Surgical shunt allowing direct passage of blood from an artery to a vein. (From Dorland, 28th ed)
An abnormal direct communication between an artery and a vein without passing through the CAPILLARIES. An A-V fistula usually leads to the formation of a dilated sac-like connection, arteriovenous aneurysm. The locations and size of the shunts determine the degree of effects on the cardiovascular functions such as BLOOD PRESSURE and HEART RATE.
Large endothelium-lined venous channels situated between the two layers of DURA MATER, the endosteal and the meningeal layers. They are devoid of valves and are parts of the venous system of dura mater. Major cranial sinuses include a postero-superior group (such as superior sagittal, inferior sagittal, straight, transverse, and occipital) and an antero-inferior group (such as cavernous, petrosal, and basilar plexus).
Congenital, inherited, or acquired abnormalities involving ARTERIES; VEINS; or venous sinuses in the BRAIN; SPINAL CORD; and MENINGES.
Abnormal formation of blood vessels that shunt arterial blood directly into veins without passing through the CAPILLARIES. They usually are crooked, dilated, and with thick vessel walls. A common type is the congenital arteriovenous fistula. The lack of blood flow and oxygen in the capillaries can lead to tissue damage in the affected areas.
Veins draining the cerebrum.
A vessel that directly interconnects an artery and a vein, and that acts as a shunt to bypass the capillary bed. Not to be confused with surgical anastomosis, nor with arteriovenous fistula.
Congenital vascular anomalies in the brain characterized by direct communication between an artery and a vein without passing through the CAPILLARIES. The locations and size of the shunts determine the symptoms including HEADACHES; SEIZURES; STROKE; INTRACRANIAL HEMORRHAGES; mass effect; and vascular steal effect.
Fluorocarbon polymers are synthetic, high-molecular-weight compounds consisting of carbon chains with fluorine atoms replacing hydrogen atoms, known for their chemical and thermal stability, as well as their resistance to water, oil, and heat, which make them useful in various medical applications such as biocompatible coatings, drug delivery systems, and implant materials.
Duration of blood flow after skin puncture. This test is used as a measure of capillary and platelet function.
The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.
An indandione that has been used as an anticoagulant. Phenindione has actions similar to WARFARIN, but it is now rarely employed because of its higher incidence of severe adverse effects. (From Martindale, The Extra Pharmacopoeia, 30th ed, p234)
A method of hemostasis utilizing various agents such as Gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and INTRACRANIAL ARTERIOVENOUS MALFORMATIONS, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage.
Surgical creation of a communication between a cerebral ventricle and the peritoneum by means of a plastic tube to permit drainage of cerebrospinal fluid for relief of hydrocephalus. (From Dorland, 28th ed)
Formation and development of a thrombus or blood clot in the blood vessel.
Tubes inserted to create communication between a cerebral ventricle and the internal jugular vein. Their emplacement permits draining of cerebrospinal fluid for relief of hydrocephalus or other condition leading to fluid accumulation in the ventricles.
The TEMPERATURE at the outer surface of the body.
A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum.
Radiography of the vascular system of the brain after injection of a contrast medium.
Veins in the neck which drain the brain, face, and neck into the brachiocephalic or subclavian veins.
A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of five named species: PAPIO URSINUS (chacma baboon), PAPIO CYNOCEPHALUS (yellow baboon), PAPIO PAPIO (western baboon), PAPIO ANUBIS (or olive baboon), and PAPIO HAMADRYAS (hamadryas baboon). Members of the Papio genus inhabit open woodland, savannahs, grassland, and rocky hill country. Some authors consider MANDRILLUS a subgenus of Papio.
Surgical venous shunt between the portal and systemic circulation to effect decompression of the portal circulation. It is performed primarily in the treatment of bleeding esophageal varices resulting from portal hypertension. Types of shunt include portacaval, splenorenal, mesocaval, splenocaval, left gastric-caval (coronary-caval), portarenal, umbilicorenal, and umbilicocaval.
The flow of BLOOD through or around an organ or region of the body.
Radiography of blood vessels after injection of a contrast medium.
Surgical portasystemic shunt between the portal vein and inferior vena cava.
An operation for the continuous emptying of ascitic fluid into the venous system. Fluid removal is based on intraperitoneal and intrathoracic superior vena cava pressure differentials and is performed via a pressure-sensitive one-way valve connected to a tube traversing the subcutaneous tissue of the chest wall to the neck where it enters the internal jugular vein and terminates in the superior vena cava. It is used in the treatment of intractable ascites.
The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA.
Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.
Dilated blood vessels in the ESOPHAGUS or GASTRIC FUNDUS that shunt blood from the portal circulation (PORTAL SYSTEM) to the systemic venous circulation. Often they are observed in individuals with portal hypertension (HYPERTENSION, PORTAL).
A syndrome characterized by central nervous system dysfunction in association with LIVER FAILURE, including portal-systemic shunts. Clinical features include lethargy and CONFUSION (frequently progressing to COMA); ASTERIXIS; NYSTAGMUS, PATHOLOGIC; brisk oculovestibular reflexes; decorticate and decerebrate posturing; MUSCLE SPASTICITY; and bilateral extensor plantar reflexes (see REFLEX, BABINSKI). ELECTROENCEPHALOGRAPHY may demonstrate triphasic waves. (From Adams et al., Principles of Neurology, 6th ed, pp1117-20; Plum & Posner, Diagnosis of Stupor and Coma, 3rd ed, p222-5)
Developmental abnormalities in any portion of the ATRIAL SEPTUM resulting in abnormal communications between the two upper chambers of the heart. Classification of atrial septal defects is based on location of the communication and types of incomplete fusion of atrial septa with the ENDOCARDIAL CUSHIONS in the fetal heart. They include ostium primum, ostium secundum, sinus venosus, and coronary sinus defects.
Vein formed by the union (at the hilus of the spleen) of several small veins from the stomach, pancreas, spleen and mesentery.
A system of vessels in which blood, after passing through one capillary bed, is conveyed through a second set of capillaries before it returns to the systemic circulation. It pertains especially to the hepatic portal system.
A short thick vein formed by union of the superior mesenteric vein and the splenic vein.
Accumulation or retention of free fluid within the peritoneal cavity.
Abnormalities in any part of the HEART SEPTUM resulting in abnormal communication between the left and the right chambers of the heart. The abnormal blood flow inside the heart may be caused by defects in the ATRIAL SEPTUM, the VENTRICULAR SEPTUM, or both.
Bleeding in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.
A form of compensated hydrocephalus characterized clinically by a slowly progressive gait disorder (see GAIT DISORDERS, NEUROLOGIC), progressive intellectual decline, and URINARY INCONTINENCE. Spinal fluid pressure tends to be in the high normal range. This condition may result from processes which interfere with the absorption of CSF including SUBARACHNOID HEMORRHAGE, chronic MENINGITIS, and other conditions. (From Adams et al., Principles of Neurology, 6th ed, pp631-3)
Short thick veins which return blood from the kidneys to the vena cava.
The circulation of the BLOOD through the LUNGS.
A condition in which the FORAMEN OVALE in the ATRIAL SEPTUM fails to close shortly after birth. This results in abnormal communications between the two upper chambers of the heart. An isolated patent ovale foramen without other structural heart defects is usually of no hemodynamic significance.
Diversion of the flow of blood from the entrance to the right atrium directly to the pulmonary arteries, avoiding the right atrium and right ventricle (Dorland, 28th ed). This a permanent procedure often performed to bypass a congenitally deformed right atrium or right ventricle.
A benign epithelial tumor of the LIVER.
Tumors or cancer of the LIVER.
Solitary or multiple benign hepatic vascular tumors, usually occurring in women of 20-50 years of age. The nodule, poorly encapsulated, consists of a central stellate fibrous scar and normal liver elements such as HEPATOCYTES, small BILE DUCTS, and KUPFFER CELLS among the intervening fibrous septa. The pale colored central scar represents large blood vessels with hyperplastic fibromuscular layer and narrowing lumen.
Pathological processes of the LIVER.
A vascular anomaly due to proliferation of BLOOD VESSELS that forms a tumor-like mass. The common types involve CAPILLARIES and VEINS. It can occur anywhere in the body but is most frequently noticed in the SKIN and SUBCUTANEOUS TISSUE. (from Stedman, 27th ed, 2000)
A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.
The first alpha-globulins to appear in mammalian sera during FETAL DEVELOPMENT and the dominant serum proteins in early embryonic life.

Sites of stenosis in AV fistulae for haemodialysis access. (1/955)

BACKGROUND: A large proportion of late failures of radiocephalic arteriovenous fistulae are related to the progression of intimal hyperplasia. The aetiology of this process is still unknown but the fistula configuration and resultant haemodynamics have been implicated. This clinical study was devised to identify sites of stenosis in patients with fistulae and relate the findings to various clinical and geometrical parameters. METHOD: Measurement of anastomotic length and angle was made intraoperatively in 25 consecutive fistulae. Post-operative assessment was carried out at regular intervals using duplex and colour-flow ultrasonography. RESULTS: Stenoses were present in all 25 of the fistulae studied at 3 months. The stenoses could be classified to three specific sites: at the anastomosis (Type 1), on the inner wall of the curved region of the cephalic vein (Type 2) and just proximal to this curved segment where the vein straightens out (Type 3). Most of Type 1 and Type 2 stenoses were not progressive while Type 3 stenoses were generally progressive. CONCLUSION: These findings emphasize the need for an effective surveillance programme of AV fistulae.  (+info)

Association of plasma fibrinogen concentration with vascular access failure in hemodialysis patients. (2/955)

BACKGROUND: Elevated plasma fibrinogen is an important risk factor for coronary artery disease in the general population and patients with chronic renal failure. High plasma fibrinogen may trigger thrombus formation in arteriovenous fistulas. We performed a prospective, cohort study to evaluate the association of plasma fibrinogen concentration with vascular access failure in patients undergoing long-term haemodialysis. METHODS: Between September 1989 and October 1995, 144 patients underwent a vascular access operation. In March 1997, 102 patients (56 M, 46 F) who had been followed up for more than 18 months (median; 37 months, range; 18-102 months) were included in the study. The median age of the patients was 52 years (range; 19-78 years). In 35 patients, renal disease was secondary to diabetes mellitus. The type of vascular access was a polytetrafluoroethylene (PTFE) graft in 17 patients. Seventy-seven patients received recombinant human erythropoietin (r-HuEPO) therapy during the follow-up period. Plasma fibrinogen, albumin, total cholesterol, hematocrit, platelets and creatinine were measured at the time of operation. Vascular access failure was defined as the occurrence of complications requiring transluminal angioplasty, thrombolytic therapy or surgical repair. RESULTS: Thirty-eight patients had at least one vascular access failure and the incidence was 0.3 (range; 0-2.4) episodes per patient-year. The survival rate of vascular access was 78% (native fistula; 80%, PTFE graft; 71%) after 12 months and 70% (native fistula; 73%, PTFE graft; 51%) after 24 months. Older age, a PTFE graft, r-HuEPO therapy, higher hematocrit, lower albumin and higher fibrinogen levels were significantly associated with vascular access failure, whereas gender, diabetes mellitus, total cholesterol and platelet count were not. Plasma fibrinogen was inversely correlated with albumin (r=-0.38, P=0.001). The cumulative vascular access survival was significantly lower in patients with high plasma fibrinogen levels (> or = 460 mg/dl) compared with patients with low levels (< 460 mg/dl) (P=0.007). Independent risk factors for vascular access failure analysed by Cox's proportional hazards model were older age (RR; 1.36 by 10-year increment), higher fibrinogen level (RR; 1.20 by 100 mg/dl increment), PTFE graft (RR; 2.28) and r-HuEPO therapy (RR; 3.79). CONCLUSION: High plasma fibrinogen level is an independent risk factor for vascular access failure in haemodialysis patients.  (+info)

Right atrial bypass grafting for central venous obstruction associated with dialysis access: another treatment option. (3/955)

PURPOSE: Central venous obstruction is a common problem in patients with chronic renal failure who undergo maintenance hemodialysis. We studied the use of right atrial bypass grafting in nine cases of central venous obstruction associated with upper extremity venous hypertension. To better understand the options for managing this condition, we discuss the roles of surgery and percutaneous transluminal angioplasty with stent placement. METHODS: All patients had previously undergone placement of bilateral temporary subclavian vein dialysis catheters. Severe arm swelling, graft thrombosis, or graft malfunction developed because of central venous stenosis or obstruction in the absence of alternative access sites. A large-diameter (10 to 16 mm) externally reinforced polytetrafluoroethylene (GoreTex) graft was used to bypass the obstructed vein and was anastomosed to the right atrial appendage. This technique was used to bypass six lesions in the subclavian vein, two lesions at the innominate vein/superior vena caval junction, and one lesion in the distal axillary vein. RESULTS: All patients except one had significant resolution of symptoms without operative mortality. Bypass grafts remained patent, allowing the arteriovenous grafts to provide functional access for 1.5 to 52 months (mean, 15.4 months) after surgery. CONCLUSION: Because no mortality directly resulted from the procedure and the morbidity rate was acceptable, this bypass grafting technique was adequate in maintaining the dialysis access needed by these patients. Because of the magnitude of the procedure, we recommend it only for the occasional patient in whom all other access sites are exhausted and in whom percutaneous dilation and/or stenting has failed.  (+info)

Volume flow measurement in hemodialysis shunts using time-domain correlation. (4/955)

Volume flow was measured in 58 hemodialysis shunts (32 grafts and 26 radial fistulas) using the color velocity imaging-quantification method. This method is based on time-domain correlation for velocity calculation and integration of time-varying velocity profiles generated by M-mode sampling. Measurements were made in the brachial artery to estimate radial fistula flow or directly in the grafts. Intraoperator reproducibility was 14.9% for fistulas and 11.6% for grafts. Flow rate was significantly lower in abnormal shunts associated with a functional disorder or a morphologic complication (808 ml/min +/- 484) than in shunts associated with no abnormalities (1401 ml/min +/- 562). Receiver operating characteristic curves showed that a flow rate of 900 ml/min for fistulas and 1300 ml/min for grafts provided 81% and 79% sensitivity and 79% and 67% specificity, respectively. A functional disorder or a morphologic complication was associated with all fistulas and grafts in which flow rates were lower than 500 ml/min and 800 ml/min, respectively.  (+info)

Prospective randomised trial of distal arteriovenous fistula as an adjunct to femoro-infrapopliteal PTFE bypass. (5/955)

OBJECTIVES: To compare graft patency and limb salvage rate following femoro-infrapopliteal bypass using ePTFE grafts with and without the addition of adjuvant arterio-venous fistula. DESIGN: A prospectively randomised controlled trial. MATERIALS: Patients referred to two teaching hospital vascular surgery units in the U.K. for the treatment of critical limb ischaemia. METHODS: Eighty-seven patients (M:F; 2.3:1) undergoing 89 femoro-intrapopliteal bypass operations with ePTFE grafts for critical limb ischaemia were randomly allocated to have AVF included in the operative procedure (n = 48) or to a control group without AVF (n = 41). An interposition vein-cuff was incorporated at the distal anastomosis in all patients. RESULTS: The cumulative rates of primary patency and limb salvage at 1-year after operation for patients with AVF were 55.2% and 54.1% compared to 53.4% and 43.2%, respectively, for the control group. The differences between the AVF and control groups did not reach statistical significance, in terms of either graft patency or limb salvage, at any stage after operation (Log-Rank test). CONCLUSIONS: AVF confers no additional significant clinical advantage over interposition vein cuff in patients having femoro-infrapopliteal bypass with ePTFE grants for critical limb ischaemia.  (+info)

Homocyst(e)ine and vascular access complications in haemodialysis patients: insights into a complex metabolic relationship. (6/955)

BACKGROUND: As elevated total homocyst(e)ine (tHcy) is associated with increased risk of vascular thrombosis, we hypothesized that the elevated levels of tHcy seen in patients on haemodialysis may be associated with an increased risk of thrombosis of native arteriovenous fistulae (vascular access failure). Our study was designed to investigate the relationship between tHcy and vascular access failure. The relationship between tHcy and mortality was explored as a secondary analysis. METHODS: The study comprised a cross-sectional analysis of 96 haemodialysis patients at a single university-affiliated hospital and a subsequent 9-month prospective follow-up of 88 of the 96 patients. RESULTS: Levels of tHcy (median 30 micromol/l) were elevated. In the initial cross-sectional sample, there was an inverse relationship between tHcy and history of vascular access failure which was not observed in the prospective study. Variables influencing the risk of vascular access failure in the prospective study included history of previous vascular access failure (RR=2.93, P=0.03), use of antiplatelet agents (RR=0.13, P=0.01), increased urea reduction ratio (RR=0.55 for a 5% increase, P=0.01) and increased weight (RR=0.61 for a 10 kg increase, P=0.02). Secondary analysis showed an unexpected inverse relationship between tHcy and mortality (RR=0.033 for 1 log increase in tHcy, P=0.006), such that the lower levels of tHcy were associated with an increased risk of death in short-term follow-up. CONCLUSION: We did not demonstrate a relationship between tHcy and risk of vascular access failure. Patients with the lowest levels of tHcy appeared to be at increased risk of death in this short-term follow-up. The relationship of tHcy to vascular access complications and death in haemodialysis patients appears complex and requires further study.  (+info)

Effects of arteriovenous fistulas on cardiac oxygen supply and demand. (7/955)

BACKGROUND: Arteriovenous (AV) fistulas used for hemodialysis access may affect cardiac load by increasing the preload while decreasing the afterload. In dogs, AV fistulas have also been shown to affect coronary perfusion negatively. We investigated the net effect of AV fistulas on cardiac oxygen supply and demand. METHODS: Aortic pressure waves were reconstructed from finger pressure recordings obtained on the nonfistula arm using a wave-form filter. Changes in systolic, mean, and diastolic aortic pressure were calculated, together with changes in heart rate (HR), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR) during a 60-second compression of AV fistulas in 10 patients. Changes in cardiac supply and demand were estimated by calculating the area under the aortic pressure curve during diastole [diastolic pressure time index (DPTI)] and systole [systolic pressure time index (SPTI)], respectively. RESULTS: During fistula compression, systolic, mean and diastolic pressure increased by 4.2 +/- 4.3, 2.6 +/- 3.0, and 2.8 +/- 2.9 mm Hg (mean +/- SD, all P < 0.05). The HR decreased by 3.8 +/- 2.5 beats per minute (P < 0.01), and SV decreased 3.7 +/- 6.1% (NS). CO decreased 9.4 +/- 8.6%, and SVR increased 14.3 +/- 11.7% (both P < 0.05). The SPTI increased by 1.5 +/- 1.5 mm Hg.sec (P < 0.01), and the DPTI increased by 7.6 +/- 8.1 mm Hg.sec (14.8% increase, P < 0.05) during compression. The ratio of supply and demand (DPTI/SPTI) improved by 13.5 +/- 13.0% (P < 0.01) when the fistula was compressed. CONCLUSION: AV fistulas have a small effect on left ventricular oxygen demand, but decrease cardiac oxygen supply considerably.  (+info)

Differential regulation of IGF-I, its receptor and GH receptor mRNAs in the right ventricle and caval vein in volume-loaded genetically hypertensive and normotensive rats. (8/955)

It has been suggested, mainly by in vitro findings, that cardiovascular tissue in the spontaneously hypertensive rat (SHR) should be more prone to proliferate/hypertrophy than that of the Wistar-Kyoto rat (WKY). The present study tests the hypothesis that the tissue of the low-pressure compartment in SHR, being structurally similar to that of the WKY, shows an increased growth response due to activation of the GH-IGF-I system. An aortocaval fistula (ACF) was induced in 64 SHR and WKY male rats and 44 rats served as controls. They were all followed for 1, 2, 4 and 7 days after surgery. In separate groups of SHR (n=4) and WKY (n=3), central venous pressure was measured by telemetry recordings prior to opening of the fistula and for up to 16 h post-surgery. Systolic blood pressure was measured during the week post-surgery. The right ventricular (RV) and the caval vein IGF-I mRNA and RV IGF-I receptor and GH receptor mRNAs were quantitated by means of solution hybridisation assay. In rats with ACF the systolic blood pressure decreased, approximately 29% in SHR and 16% in WKY between 1 and 7 days post-surgery (P<0.05, n=5-6 in each group). SHR with ACF showed a transient elevation in central venous pressure vs WKY. Within the week following fistula induction both strains showed a similar, pronounced increase in RV hypertrophy. SHR with ACF showed a smaller, or even blunted, overall response with respect to activation of the GH-IGF-I system compared with WKY, the latter showing clear-cut elevation of gene expressions. Two days after shunt opening in SHR, RV and caval vein IGF-I mRNA increased by 57% and 108% (P<0.05 for both, n=5-6 in each group) respectively, and these expressions were then turned off, whereas RV GH receptor and IGF-I receptor mRNA expression remained unaffected compared with WKY rats. WKY rats showed on average a later and a greater response of GH-IGF-I system mRNA expression vs SHR. The present in vivo study suggests that the SHR requires less activation of the GH-IGF-I system for creating a given adaptive structural growth response.  (+info)

An arteriovenous shunt is a surgically created connection between an artery and a vein. This procedure is typically performed to reroute blood flow or to provide vascular access for various medical treatments. In a surgical setting, the creation of an arteriovenous shunt involves connecting an artery directly to a vein, bypassing the capillary network in between.

There are different types of arteriovenous shunts used for specific medical purposes:

1. Arteriovenous Fistula (AVF): This is a surgical connection created between an artery and a vein, usually in the arm or leg. The procedure involves dissecting both the artery and vein, then suturing them directly together. Over time, the increased blood flow to the vein causes it to dilate and thicken, making it suitable for repeated needle punctures during hemodialysis treatments for patients with kidney failure.
2. Arteriovenous Graft (AVG): An arteriovenous graft is a synthetic tube used to connect an artery and a vein when a direct AVF cannot be created due to insufficient vessel size or poor quality. The graft can be made of various materials, such as polytetrafluoroethylene (PTFE) or Dacron. Grafts are more prone to infection and clotting compared to native AVFs but remain an essential option for patients requiring hemodialysis access.
3. Central Venous Catheter (CVC): A central venous catheter is a flexible tube inserted into a large vein, often in the neck or groin, and advanced towards the heart. CVCs can be used as temporary arteriovenous shunts for patients who require immediate hemodialysis access but do not have time to wait for an AVF or AVG to mature. However, they are associated with higher risks of infection and thrombosis compared to native AVFs and AVGs.

In summary, a surgical arteriovenous shunt is a connection between an artery and a vein established through a medical procedure. The primary purpose of these shunts is to provide vascular access for hemodialysis in patients with end-stage renal disease or to serve as temporary access when native AVFs or AVGs are not feasible.

An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. This connection causes blood to flow directly from the artery into the vein, bypassing the capillary network that would normally distribute the oxygen-rich blood to the surrounding tissues.

Arteriovenous fistulas can occur as a result of trauma, disease, or as a planned surgical procedure for patients who require hemodialysis, a treatment for advanced kidney failure. In hemodialysis, the arteriovenous fistula serves as a site for repeated access to the bloodstream, allowing for efficient removal of waste products and excess fluids.

The medical definition of an arteriovenous fistula is:

"An abnormal communication between an artery and a vein, usually created by surgical means for hemodialysis access or occurring as a result of trauma, congenital defects, or disease processes such as vasculitis or neoplasm."

Cranial sinuses are a part of the venous system in the human head. They are air-filled spaces located within the skull and are named according to their location. The cranial sinuses include:

1. Superior sagittal sinus: It runs along the top of the brain, inside the skull, and drains blood from the scalp and the veins of the brain.
2. Inferior sagittal sinus: It runs along the bottom of the brain and drains into the straight sinus.
3. Straight sinus: It is located at the back of the brain and receives blood from the inferior sagittal sinus and great cerebral vein.
4. Occipital sinuses: They are located at the back of the head and drain blood from the scalp and skull.
5. Cavernous sinuses: They are located on each side of the brain, near the temple, and receive blood from the eye and surrounding areas.
6. Sphenoparietal sinus: It is a small sinus that drains blood from the front part of the brain into the cavernous sinus.
7. Petrosquamosal sinuses: They are located near the ear and drain blood from the scalp and skull.

The cranial sinuses play an essential role in draining blood from the brain and protecting it from injury.

Central nervous system (CNS) vascular malformations are abnormal tangles or masses of blood vessels in the brain or spinal cord. These malformations can be congenital (present at birth) or acquired (develop later in life). They can vary in size, location, and symptoms, which may include headaches, seizures, weakness, numbness, difficulty speaking or understanding speech, and vision problems.

There are several types of CNS vascular malformations, including:

1. Arteriovenous malformations (AVMs): These are tangles of arteries and veins with a direct connection between them, bypassing the capillary network. AVMs can cause bleeding in the brain or spinal cord, leading to stroke or neurological deficits.
2. Cavernous malformations: These are clusters of dilated, thin-walled blood vessels that form a sac-like structure. They can rupture and bleed, causing symptoms such as seizures, headaches, or neurological deficits.
3. Developmental venous anomalies (DVAs): These are benign vascular malformations characterized by an abnormal pattern of veins that drain blood from the brain. DVAs are usually asymptomatic but can be associated with other vascular malformations.
4. Capillary telangiectasias: These are small clusters of dilated capillaries in the brain or spinal cord. They are usually asymptomatic and found incidentally during imaging studies.
5. Moyamoya disease: This is a rare, progressive cerebrovascular disorder characterized by the narrowing or blockage of the internal carotid arteries and their branches. This can lead to decreased blood flow to the brain, causing symptoms such as headaches, seizures, and strokes.

The diagnosis of CNS vascular malformations typically involves imaging studies such as MRI or CT scans, and sometimes angiography. Treatment options may include observation, medication, surgery, or endovascular procedures, depending on the type, location, and severity of the malformation.

Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels that directly connect arteries and veins, bypassing the capillary system. This results in a high-flow and high-pressure circulation in the affected area. AVMs can occur anywhere in the body but are most common in the brain and spine. They can vary in size and may cause symptoms such as headaches, seizures, or bleeding in the brain. In some cases, AVMs may not cause any symptoms and may only be discovered during imaging tests for other conditions. Treatment options include surgery, radiation therapy, or embolization to reduce the flow of blood through the malformation and prevent complications.

Cerebral veins are the blood vessels that carry deoxygenated blood from the brain to the dural venous sinuses, which are located between the layers of tissue covering the brain. The largest cerebral vein is the superior sagittal sinus, which runs along the top of the brain. Other major cerebral veins include the straight sinus, transverse sinus, sigmoid sinus, and cavernous sinus. These veins receive blood from smaller veins called venules that drain the surface and deep structures of the brain. The cerebral veins play an important role in maintaining normal circulation and pressure within the brain.

An arteriovenous (AV) anastomosis is a connection or short channel between an artery and a vein that bypasses the capillary bed. In a normal physiological condition, blood flows from the arteries to the capillaries, where oxygen and nutrients are exchanged with the surrounding tissues, and then drains into veins. However, in an AV anastomosis, blood flows directly from the artery to the vein without passing through the capillary network.

AV anastomoses can occur naturally or be created surgically for various medical purposes. For example, they may be created during bypass surgery to reroute blood flow around a blocked or damaged vessel. In some cases, AV anastomoses may also develop as a result of certain medical conditions, such as cirrhosis or arteriovenous malformations (AVMs). AVMs are abnormal connections between arteries and veins that can lead to the formation of an AV anastomosis.

It is important to note that while AV anastomoses can be beneficial in certain medical situations, they can also have negative consequences if they occur inappropriately or become too large. For example, excessive AV anastomoses can lead to high-flow shunts, which can cause tissue damage and other complications.

Intracranial arteriovenous malformations (AVMs) are abnormal, tangled connections between the arteries and veins in the brain. These connections bypass the capillary system, which can lead to high-flow shunting and potential complications such as hemorrhage, stroke, or neurological deficits. AVMs are congenital conditions, meaning they are present at birth, although symptoms may not appear until later in life. They are relatively rare, affecting approximately 0.1% of the population. Treatment options for AVMs include surgery, radiation therapy, and endovascular embolization, depending on the size, location, and specific characteristics of the malformation.

Fluorocarbon polymers are a type of synthetic polymeric material that contain carbon-fluorine bonds. These materials are known for their chemical inertness, high stability, and resistance to heat, chemicals, and water. They are often used in various medical applications such as in the coating of medical devices, implants, and drug delivery systems due to their biocompatibility and non-reactive properties.

Fluorocarbon polymers can be classified into two main categories: perfluoropolymers and fluoropolymers. Perfluoropolymers contain only carbon and fluorine atoms, while fluoropolymers contain other elements such as hydrogen, oxygen, or nitrogen in addition to carbon and fluorine.

Examples of fluorocarbon polymers used in medical applications include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and ethylene tetrafluoroethylene (ETFE). These materials have a wide range of properties that make them useful in various medical applications, such as low coefficient of friction, high electrical resistance, and excellent chemical resistance.

Bleeding time is a medical test that measures the time it takes for a small blood vessel to stop bleeding after being cut. It's used to evaluate platelet function and the effectiveness of blood clotting. The most common method used to measure bleeding time is the Ivy method, which involves making a standardized incision on the forearm and measuring the time it takes for the bleeding to stop. A normal bleeding time ranges from 2 to 9 minutes, but this can vary depending on the specific method used. Prolonged bleeding time may indicate an impairment in platelet function or clotting factor deficiency.

Dura Mater is the thickest and outermost of the three membranes (meninges) that cover the brain and spinal cord. It provides protection and support to these delicate structures. The other two layers are called the Arachnoid Mater and the Pia Mater, which are thinner and more delicate than the Dura Mater. Together, these three layers form a protective barrier around the central nervous system.

Phenindione is an anticoagulant medication, which is primarily used in the prevention and treatment of thromboembolic disorders such as deep vein thrombosis (DVT), pulmonary embolism (PE), and certain types of strokes. It works by inhibiting the formation of blood clots in the body.

Phenindione is a derivative of indandione, and it functions by blocking the activity of vitamin K-dependent coagulation factors II, VII, IX, and X, thereby prolonging the clotting time of the blood. It is available in oral form as tablets or capsules.

It's important to note that phenindione has largely been replaced by other anticoagulants such as warfarin due to its narrow therapeutic index, higher risk of adverse effects, and interactions with other medications. Therefore, it is not commonly used in clinical practice today.

Therapeutic embolization is a medical procedure that involves intentionally blocking or obstructing blood vessels to stop excessive bleeding or block the flow of blood to a tumor or abnormal tissue. This is typically accomplished by injecting small particles, such as microspheres or coils, into the targeted blood vessel through a catheter, which is inserted into a larger blood vessel and guided to the desired location using imaging techniques like X-ray or CT scanning. The goal of therapeutic embolization is to reduce the size of a tumor, control bleeding, or block off abnormal blood vessels that are causing problems.

A Ventriculoperitoneal (VP) shunt is a surgical procedure that involves the insertion of a long, flexible tube (shunt) into the cerebral ventricles of the brain to drain excess cerebrospinal fluid (CSF). The other end of the shunt is directed into the peritoneal cavity, where the CSF can be absorbed.

The VP shunt is typically used to treat hydrocephalus, a condition characterized by an abnormal accumulation of CSF within the ventricles of the brain, which can cause increased intracranial pressure and damage to the brain. By diverting the excess CSF from the ventricles into the peritoneal cavity, the VP shunt helps to relieve the symptoms of hydrocephalus and prevent further neurological damage.

The shunt system consists of several components, including a ventricular catheter that is placed in the ventricle, a one-way valve that regulates the flow of CSF, and a distal catheter that is directed into the peritoneal cavity. The valve helps to prevent backflow of CSF into the brain and ensures that the fluid flows in only one direction, from the ventricles to the peritoneal cavity.

VP shunts are generally safe and effective, but they can be associated with complications such as infection, obstruction, or malfunction of the shunt system. Regular follow-up with a healthcare provider is necessary to monitor the function of the shunt and ensure that any potential issues are addressed promptly.

Thrombosis is the formation of a blood clot (thrombus) inside a blood vessel, obstructing the flow of blood through the circulatory system. When a clot forms in an artery, it can cut off the supply of oxygen and nutrients to the tissues served by that artery, leading to damage or tissue death. If a thrombus forms in the heart, it can cause a heart attack. If a thrombus breaks off and travels through the bloodstream, it can lodge in a smaller vessel, causing blockage and potentially leading to damage in the organ that the vessel supplies. This is known as an embolism.

Thrombosis can occur due to various factors such as injury to the blood vessel wall, abnormalities in blood flow, or changes in the composition of the blood. Certain medical conditions, medications, and lifestyle factors can increase the risk of thrombosis. Treatment typically involves anticoagulant or thrombolytic therapy to dissolve or prevent further growth of the clot, as well as addressing any underlying causes.

Cerebrospinal fluid (CSF) shunts are medical devices used to divert the flow of excess CSF from the brain and spinal cord to another part of the body, usually the abdominal cavity. The shunt consists of a catheter, a valve, and a reservoir.

The catheter is inserted into one of the ventricles in the brain or the subarachnoid space surrounding the spinal cord to drain the excess CSF. The valve regulates the flow of CSF to prevent over-drainage, which can cause complications such as low CSF pressure and brain sagging. The reservoir is a small chamber that allows for easy access to the shunt system for monitoring and adjusting the pressure settings.

CSF shunts are typically used to treat conditions associated with increased production or impaired absorption of CSF, such as hydrocephalus, communicating hydrocephalus, normal pressure hydrocephalus, and pseudotumor cerebri. By reducing the buildup of CSF in the brain, shunts can help alleviate symptoms such as headaches, nausea, vomiting, vision problems, and cognitive impairment.

It is important to note that while CSF shunts are effective in managing these conditions, they also carry risks of complications such as infection, obstruction, malfunction, and over-drainage. Regular monitoring and follow-up care are necessary to ensure proper functioning and minimize the risk of complications.

Skin temperature is the measure of heat emitted by the skin, which can be an indicator of the body's core temperature. It is typically lower than the body's internal temperature and varies depending on factors such as environmental temperature, blood flow, and physical activity. Skin temperature is often used as a vital sign in medical settings and can be measured using various methods, including thermal scanners, digital thermometers, or mercury thermometers. Changes in skin temperature may also be associated with certain medical conditions, such as inflammation, infection, or nerve damage.

The hepatic artery is a branch of the celiac trunk or abdominal aorta that supplies oxygenated blood to the liver. It typically divides into two main branches, the right and left hepatic arteries, which further divide into smaller vessels to supply different regions of the liver. The hepatic artery also gives off branches to supply other organs such as the gallbladder, pancreas, and duodenum.

It's worth noting that there is significant variability in the anatomy of the hepatic artery, with some individuals having additional branches or variations in the origin of the vessel. This variability can have implications for surgical procedures involving the liver and surrounding organs.

Cerebral angiography is a medical procedure that involves taking X-ray images of the blood vessels in the brain after injecting a contrast dye into them. This procedure helps doctors to diagnose and treat various conditions affecting the blood vessels in the brain, such as aneurysms, arteriovenous malformations, and stenosis (narrowing of the blood vessels).

During the procedure, a catheter is inserted into an artery in the leg and threaded through the body to the blood vessels in the neck or brain. The contrast dye is then injected through the catheter, and X-ray images are taken to visualize the blood flow through the brain's blood vessels.

Cerebral angiography provides detailed images of the blood vessels in the brain, allowing doctors to identify any abnormalities or blockages that may be causing symptoms or increasing the risk of stroke. Based on the results of the cerebral angiography, doctors can develop a treatment plan to address these issues and prevent further complications.

The jugular veins are a pair of large, superficial veins that carry blood from the head and neck to the heart. They are located in the neck and are easily visible when looking at the side of a person's neck. The external jugular vein runs along the surface of the muscles in the neck, while the internal jugular vein runs within the carotid sheath along with the carotid artery and the vagus nerve.

The jugular veins are important in clinical examinations because they can provide information about a person's cardiovascular function and intracranial pressure. For example, distention of the jugular veins may indicate heart failure or increased intracranial pressure, while decreased venous pulsations may suggest a low blood pressure or shock.

It is important to note that medical conditions such as deep vein thrombosis (DVT) can also affect the jugular veins and can lead to serious complications if not treated promptly.

"Papio" is a term used in the field of primatology, specifically for a genus of Old World monkeys known as baboons. It's not typically used in human or medical contexts. Baboons are large monkeys with robust bodies and distinctive dog-like faces. They are native to various parts of Africa and are known for their complex social structures and behaviors.

A portosystemic shunt is a surgical procedure that creates a connection between the portal vein (the blood vessel that carries blood from the digestive organs to the liver) and another systemic vein (a vein that carries blood away from the liver). This procedure is typically performed in animals, particularly dogs, to treat conditions such as portal hypertension or liver disease.

In a surgical portosystemic shunt, the surgeon creates a connection between the portal vein and a systemic vein, allowing blood from the digestive organs to bypass the liver. This can help to reduce the pressure in the portal vein and improve blood flow to the liver. The specific type of shunt created and the surgical approach used may vary depending on the individual patient's needs and the surgeon's preference.

It is important to note that while a surgical portosystemic shunt can be an effective treatment for certain conditions, it is not without risks and potential complications. As with any surgical procedure, there is always a risk of infection, bleeding, or other complications. Additionally, the creation of a portosystemic shunt can have long-term effects on the liver and overall health of the patient. It is important for pet owners to carefully consider the risks and benefits of this procedure and to discuss any questions or concerns they may have with their veterinarian.

Regional blood flow (RBF) refers to the rate at which blood flows through a specific region or organ in the body, typically expressed in milliliters per minute per 100 grams of tissue (ml/min/100g). It is an essential physiological parameter that reflects the delivery of oxygen and nutrients to tissues while removing waste products. RBF can be affected by various factors such as metabolic demands, neural regulation, hormonal influences, and changes in blood pressure or vascular resistance. Measuring RBF is crucial for understanding organ function, diagnosing diseases, and evaluating the effectiveness of treatments.

Angiography is a medical procedure in which an x-ray image is taken to visualize the internal structure of blood vessels, arteries, or veins. This is done by injecting a radiopaque contrast agent (dye) into the blood vessel using a thin, flexible catheter. The dye makes the blood vessels visible on an x-ray image, allowing doctors to diagnose and treat various medical conditions such as blockages, narrowing, or malformations of the blood vessels.

There are several types of angiography, including:

* Cardiac angiography (also called coronary angiography) - used to examine the blood vessels of the heart
* Cerebral angiography - used to examine the blood vessels of the brain
* Peripheral angiography - used to examine the blood vessels in the limbs or other parts of the body.

Angiography is typically performed by a radiologist, cardiologist, or vascular surgeon in a hospital setting. It can help diagnose conditions such as coronary artery disease, aneurysms, and peripheral arterial disease, among others.

A portacaval shunt is a surgical procedure that creates an alternate pathway for blood flow between the portal vein and the inferior vena cava. The portal vein carries blood from the gastrointestinal tract, liver, spleen, and pancreas to the liver. In certain medical conditions, such as severe liver disease or portal hypertension, the blood pressure in the portal vein becomes abnormally high, which can lead to serious complications like variceal bleeding.

In a surgical portacaval shunt procedure, a surgeon creates a connection between the portal vein and the inferior vena cava, allowing a portion of the blood from the portal vein to bypass the liver and flow directly into the systemic circulation. This helps reduce the pressure in the portal vein and prevent complications associated with portal hypertension.

There are different types of portacaval shunts, including:

1. Direct portacaval shunt: In this procedure, the surgeon directly connects the portal vein to the inferior vena cava.
2. Side-to-side portacaval shunt: Here, the surgeon creates an anastomosis (connection) between a side branch of the portal vein and the inferior vena cava.
3. H-type shunt: This involves creating two separate connections between the portal vein and the inferior vena cava, forming an "H" shape.

It is important to note that while portacaval shunts can be effective in managing complications of portal hypertension, they may also have potential risks and side effects, such as worsening liver function, encephalopathy, or heart failure. Therefore, the decision to perform a portacaval shunt should be made carefully, considering the individual patient's medical condition and overall health.

A Peritoneovenous Shunt is a medical device used to treat severe ascites, a condition characterized by the accumulation of excess fluid in the abdominal cavity. The shunt consists of a small tube or catheter that is surgically implanted into the abdominal cavity and connected to another tube that is inserted into a vein, usually in the chest or neck.

The shunt works by allowing the excess fluid in the abdomen to flow through the tube and into the bloodstream, where it can be eliminated from the body through the kidneys. This helps to alleviate the symptoms of ascites, such as abdominal pain and swelling, and can improve the patient's quality of life.

Peritoneovenous shunts are typically used in patients who have not responded to other treatments for ascites, such as diuretics or paracentesis (a procedure in which excess fluid is drained from the abdomen using a needle and syringe). While peritoneovenous shunts can be effective in managing ascites, they do carry some risks, including infection, bleeding, and blockage of the shunt. As with any surgical procedure, it's important for patients to discuss the potential benefits and risks with their healthcare provider before deciding whether a peritoneovenous shunt is right for them.

Platelet aggregation is the clumping together of platelets (thrombocytes) in the blood, which is an essential step in the process of hemostasis (the stopping of bleeding) after injury to a blood vessel. When the inner lining of a blood vessel is damaged, exposure of subendothelial collagen and tissue factor triggers platelet activation. Activated platelets change shape, become sticky, and release the contents of their granules, which include ADP (adenosine diphosphate).

ADP then acts as a chemical mediator to attract and bind additional platelets to the site of injury, leading to platelet aggregation. This forms a plug that seals the damaged vessel and prevents further blood loss. Platelet aggregation is also a crucial component in the formation of blood clots (thrombosis) within blood vessels, which can have pathological consequences such as heart attacks and strokes if they obstruct blood flow to vital organs.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

Hydrocephalus is a medical condition characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the brain, leading to an increase in intracranial pressure and potentially causing damage to the brain tissues. This excessive buildup of CSF can result from either overproduction or impaired absorption of the fluid, which typically causes the ventricles (fluid-filled spaces) inside the brain to expand and put pressure on surrounding brain structures.

The condition can be congenital, present at birth due to genetic factors or abnormalities during fetal development, or acquired later in life as a result of injuries, infections, tumors, or other disorders affecting the brain's ability to regulate CSF flow and absorption. Symptoms may vary depending on age, severity, and duration but often include headaches, vomiting, balance problems, vision issues, cognitive impairment, and changes in behavior or personality.

Treatment for hydrocephalus typically involves surgically implanting a shunt system that diverts the excess CSF from the brain to another part of the body where it can be absorbed, such as the abdominal cavity. In some cases, endoscopic third ventriculostomy (ETV) might be an alternative treatment option, creating a new pathway for CSF flow within the brain. Regular follow-ups with neurosurgeons and other healthcare professionals are essential to monitor the condition and make any necessary adjustments to the treatment plan.

Portal hypertension is a medical condition characterized by an increased pressure in the portal vein, which is the large blood vessel that carries blood from the intestines, spleen, and pancreas to the liver. Normal portal venous pressure is approximately 5-10 mmHg. Portal hypertension is defined as a portal venous pressure greater than 10 mmHg.

The most common cause of portal hypertension is cirrhosis of the liver, which leads to scarring and narrowing of the small blood vessels in the liver, resulting in increased resistance to blood flow. Other causes include blood clots in the portal vein, inflammation of the liver or bile ducts, and invasive tumors that block the flow of blood through the liver.

Portal hypertension can lead to a number of complications, including the development of abnormal blood vessels (varices) in the esophagus, stomach, and intestines, which are prone to bleeding. Ascites, or the accumulation of fluid in the abdominal cavity, is another common complication of portal hypertension. Other potential complications include encephalopathy, which is a condition characterized by confusion, disorientation, and other neurological symptoms, and an increased risk of bacterial infections.

Treatment of portal hypertension depends on the underlying cause and the severity of the condition. Medications to reduce pressure in the portal vein, such as beta blockers or nitrates, may be used. Endoscopic procedures to band or inject varices can help prevent bleeding. In severe cases, surgery or liver transplantation may be necessary.

Esophageal varices and gastric varices are abnormal, enlarged veins in the lower part of the esophagus (the tube that connects the throat to the stomach) and in the stomach lining, respectively. They occur as a result of increased pressure in the portal vein, which is the large blood vessel that carries blood from the digestive organs to the liver. This condition is known as portal hypertension.

Esophageal varices are more common than gastric varices and tend to be more symptomatic. They can cause bleeding, which can be life-threatening if not treated promptly. Gastric varices may also bleed, but they are often asymptomatic until they rupture.

The most common causes of esophageal and gastric varices are cirrhosis (scarring of the liver) and portal hypertension due to other liver diseases such as schistosomiasis or Budd-Chiari syndrome. Treatment options for esophageal and gastric varices include medications to reduce bleeding, endoscopic therapies to treat active bleeding or prevent recurrent bleeding, and surgical procedures to relieve portal hypertension.

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome associated with liver dysfunction and/or portosystemic shunting. It results from the accumulation of toxic substances, such as ammonia and inflammatory mediators, which are normally metabolized by the liver. HE can present with a wide range of symptoms, including changes in sleep-wake cycle, altered mental status, confusion, disorientation, asterixis (flapping tremor), and in severe cases, coma. The diagnosis is based on clinical evaluation, neuropsychological testing, and exclusion of other causes of cognitive impairment. Treatment typically involves addressing the underlying liver dysfunction, reducing ammonia production through dietary modifications and medications, and preventing further episodes with lactulose or rifaximin therapy.

Atrial septal defect (ASD) is a type of congenital heart defect that involves the septum, which is the wall that separates the two upper chambers of the heart (atria). An ASD is a hole or abnormal opening in the atrial septum, allowing oxygen-rich blood to leak into the oxygen-poor blood chambers in the heart. This leads to an overload of blood in the right side of the heart, which can cause enlargement of the heart and increased work for the right ventricle.

ASDs can vary in size, and small defects may not cause any symptoms or require treatment. Larger defects, however, can result in symptoms such as shortness of breath, fatigue, and heart rhythm abnormalities. Over time, if left untreated, ASDs can lead to complications like pulmonary hypertension, atrial fibrillation, and stroke.

Treatment for ASD typically involves surgical closure of the defect or catheter-based procedures using devices to close the hole. The choice of treatment depends on factors such as the size and location of the defect, the patient's age and overall health, and the presence of any coexisting conditions.

The splenic vein is a large, thin-walled vein that carries oxygenated blood from the spleen and pancreas to the liver. It is formed by the union of several smaller veins that drain the upper part of the stomach, the pancreas, and the left side of the colon (splenic flexure). The splenic vein runs along the top border of the pancreas and merges with the superior mesenteric vein to form the portal vein. This venous system allows for the filtration and detoxification of blood by the liver before it is distributed to the rest of the body.

A portal system in medicine refers to a venous system in which veins from various tissues or organs (known as tributaries) drain into a common large vessel (known as the portal vein), which then carries the blood to a specific organ for filtration and processing before it is returned to the systemic circulation. The most well-known example of a portal system is the hepatic portal system, where veins from the gastrointestinal tract, spleen, pancreas, and stomach merge into the portal vein and then transport blood to the liver for detoxification and nutrient processing. Other examples include the hypophyseal portal system, which connects the hypothalamus to the anterior pituitary gland, and the renal portal system found in some animals.

The portal vein is the large venous trunk that carries blood from the gastrointestinal tract, spleen, pancreas, and gallbladder to the liver. It is formed by the union of the superior mesenteric vein (draining the small intestine and a portion of the large intestine) and the splenic vein (draining the spleen and pancreas). The portal vein then divides into right and left branches within the liver, where the blood flows through the sinusoids and gets enriched with oxygen and nutrients before being drained by the hepatic veins into the inferior vena cava. This unique arrangement allows the liver to process and detoxify the absorbed nutrients, remove waste products, and regulate metabolic homeostasis.

Ascites is an abnormal accumulation of fluid in the peritoneal cavity, which is the space between the lining of the abdominal wall and the organs within it. This buildup of fluid can cause the belly to swell and become distended. Ascites can be caused by various medical conditions, including liver cirrhosis, cancer, heart failure, and kidney disease. The accumulation of fluid in the peritoneal cavity can lead to complications such as infection, reduced mobility, and difficulty breathing. Treatment for ascites depends on the underlying cause and may include diuretics, paracentesis (a procedure to remove excess fluid from the abdomen), or treatment of the underlying medical condition.

A heart septal defect is a type of congenital heart defect, which means it is present at birth. It involves an abnormal opening in the septum, the wall that separates the two sides of the heart. This opening allows oxygen-rich blood to leak into the oxygen-poor blood chambers in the heart.

There are several types of heart septal defects, including:

1. Atrial Septal Defect (ASD): A hole in the atrial septum, the wall between the two upper chambers of the heart (the right and left atria).
2. Ventricular Septal Defect (VSD): A hole in the ventricular septum, the wall between the two lower chambers of the heart (the right and left ventricles).
3. Atrioventricular Septal Defect (AVSD): A combination of an ASD and a VSD, often accompanied by malformation of the mitral and/or tricuspid valves.

The severity of a heart septal defect depends on the size of the opening and its location in the septum. Small defects may cause no symptoms and may close on their own over time. Larger defects can lead to complications, such as heart failure, pulmonary hypertension, or infective endocarditis, and may require medical or surgical intervention.

Gastrointestinal (GI) hemorrhage is a term used to describe any bleeding that occurs in the gastrointestinal tract, which includes the esophagus, stomach, small intestine, large intestine, and rectum. The bleeding can range from mild to severe and can produce symptoms such as vomiting blood, passing black or tarry stools, or having low blood pressure.

GI hemorrhage can be classified as either upper or lower, depending on the location of the bleed. Upper GI hemorrhage refers to bleeding that occurs above the ligament of Treitz, which is a point in the small intestine where it becomes narrower and turns a corner. Common causes of upper GI hemorrhage include gastritis, ulcers, esophageal varices, and Mallory-Weiss tears.

Lower GI hemorrhage refers to bleeding that occurs below the ligament of Treitz. Common causes of lower GI hemorrhage include diverticulosis, colitis, inflammatory bowel disease, and vascular abnormalities such as angiodysplasia.

The diagnosis of GI hemorrhage is often made based on the patient's symptoms, medical history, physical examination, and diagnostic tests such as endoscopy, CT scan, or radionuclide scanning. Treatment depends on the severity and cause of the bleeding and may include medications, endoscopic procedures, surgery, or a combination of these approaches.

Normal pressure hydrocephalus (NPH) is a type of hydrocephalus that occurs in older adults and is characterized by the accumulation of cerebrospinal fluid (CSF) in the brain's ventricles, leading to enlargement of the ventricles while maintaining normal or near-normal CSF pressure. This condition can cause a triad of symptoms including gait disturbance, cognitive impairment, and urinary incontinence.

The exact cause of NPH is not well understood, but it may be associated with conditions such as previous meningitis, subarachnoid hemorrhage, or head trauma. In some cases, the cause may be idiopathic, meaning there is no known underlying condition.

Diagnosis of NPH typically involves a combination of clinical evaluation, imaging studies (such as CT or MRI scans), and sometimes lumbar puncture to measure CSF pressure and assess the patient's response to removal of CSF. Treatment usually involves surgical implantation of a shunt system that diverts excess CSF from the ventricles to another part of the body where it can be absorbed, such as the abdominal cavity. This procedure can help alleviate symptoms and improve quality of life for some patients with NPH.

The renal veins are a pair of large veins that carry oxygen-depleted blood and waste products from the kidneys to the inferior vena cava, which is the largest vein in the body that returns blood to the heart. The renal veins are formed by the union of several smaller veins that drain blood from different parts of the kidney.

In humans, the right renal vein is shorter and passes directly into the inferior vena cava, while the left renal vein is longer and passes in front of the aorta before entering the inferior vena cava. The left renal vein also receives blood from the gonadal (testicular or ovarian) veins, suprarenal (adrenal) veins, and the lumbar veins.

It is important to note that the renal veins are vulnerable to compression by surrounding structures, such as the overlying artery or a tumor, which can lead to renal vein thrombosis, a serious condition that requires prompt medical attention.

Pulmonary circulation refers to the process of blood flow through the lungs, where blood picks up oxygen and releases carbon dioxide. This is a vital part of the overall circulatory system, which delivers nutrients and oxygen to the body's cells while removing waste products like carbon dioxide.

In pulmonary circulation, deoxygenated blood from the systemic circulation returns to the right atrium of the heart via the superior and inferior vena cava. The blood then moves into the right ventricle through the tricuspid valve and gets pumped into the pulmonary artery when the right ventricle contracts.

The pulmonary artery divides into smaller vessels called arterioles, which further branch into a vast network of tiny capillaries in the lungs. Here, oxygen from the alveoli diffuses into the blood, binding to hemoglobin in red blood cells, while carbon dioxide leaves the blood and is exhaled through the nose or mouth.

The now oxygenated blood collects in venules, which merge to form pulmonary veins. These veins transport the oxygen-rich blood back to the left atrium of the heart, where it enters the systemic circulation once again. This continuous cycle enables the body's cells to receive the necessary oxygen and nutrients for proper functioning while disposing of waste products.

Patent Foramen Ovale (PFO) is a medical condition where the foramen ovale, an opening between the left and right atria of the heart in a fetus, does not close completely after birth. This results in a small flap-like opening that allows blood to pass from the right atrium to the left atrium. While this condition is typically harmless in itself, it can potentially allow blood clots to pass from the right side of the heart to the left, which could then travel to the brain and cause a stroke. Patent Foramen Ovale is usually an incidental finding during tests for other conditions.

A "Heart Bypass, Right" or Right Coronary Artery Bypass Graft (RCA Bypass) is a surgical procedure that aims to improve the blood supply to the right side of the heart. It involves grafting a healthy blood vessel, usually taken from another part of the body, to divert blood flow around a blocked or narrowed section of the right coronary artery (RCA). The RCA supplies blood to the right ventricle and the back of the left ventricle. By creating this bypass, the surgery helps restore adequate oxygenated blood flow to the heart muscle, reducing the risk of damage or failure due to insufficient blood supply, and alleviating symptoms such as angina and shortness of breath.

It is important to note that "Heart Bypass, Right" specifically refers to bypass surgery on the right coronary artery, while a standard "Heart Bypass Surgery," also known as Coronary Artery Bypass Grafting (CABG), typically involves bypassing blockages in multiple coronary arteries.

A liver cell adenoma is a benign tumor that develops in the liver and is composed of cells similar to those normally found in the liver (hepatocytes). These tumors are usually solitary, but multiple adenomas can occur, especially in women who have taken oral contraceptives for many years. Liver cell adenomas are typically asymptomatic and are often discovered incidentally during imaging studies performed for other reasons. In rare cases, they may cause symptoms such as abdominal pain or discomfort, or complications such as bleeding or rupture. Treatment options include monitoring with periodic imaging studies or surgical removal of the tumor.

Liver neoplasms refer to abnormal growths in the liver that can be benign or malignant. Benign liver neoplasms are non-cancerous tumors that do not spread to other parts of the body, while malignant liver neoplasms are cancerous tumors that can invade and destroy surrounding tissue and spread to other organs.

Liver neoplasms can be primary, meaning they originate in the liver, or secondary, meaning they have metastasized (spread) to the liver from another part of the body. Primary liver neoplasms can be further classified into different types based on their cell of origin and behavior, including hepatocellular carcinoma, cholangiocarcinoma, and hepatic hemangioma.

The diagnosis of liver neoplasms typically involves a combination of imaging studies, such as ultrasound, CT scan, or MRI, and biopsy to confirm the type and stage of the tumor. Treatment options depend on the type and extent of the neoplasm and may include surgery, radiation therapy, chemotherapy, or liver transplantation.

Focal nodular hyperplasia (FNH) is a benign liver mass, which means it's a non-cancerous growth. It is characterized by the presence of multiple nodules or "lesions" in the liver that are well-circumscribed and have a distinctive "stars in the sky" appearance on histopathology. These lesions are composed of abnormal arrangements of liver cells, bile ducts, and blood vessels. FNH is usually discovered incidentally during imaging studies performed for unrelated reasons. It's more common in women than men, and while its cause remains unclear, it has been linked to hormonal factors. Most cases do not require treatment unless they become symptomatic or complications arise.

Liver diseases refer to a wide range of conditions that affect the normal functioning of the liver. The liver is a vital organ responsible for various critical functions such as detoxification, protein synthesis, and production of biochemicals necessary for digestion.

Liver diseases can be categorized into acute and chronic forms. Acute liver disease comes on rapidly and can be caused by factors like viral infections (hepatitis A, B, C, D, E), drug-induced liver injury, or exposure to toxic substances. Chronic liver disease develops slowly over time, often due to long-term exposure to harmful agents or inherent disorders of the liver.

Common examples of liver diseases include hepatitis, cirrhosis (scarring of the liver tissue), fatty liver disease, alcoholic liver disease, autoimmune liver diseases, genetic/hereditary liver disorders (like Wilson's disease and hemochromatosis), and liver cancers. Symptoms may vary widely depending on the type and stage of the disease but could include jaundice, abdominal pain, fatigue, loss of appetite, nausea, and weight loss.

Early diagnosis and treatment are essential to prevent progression and potential complications associated with liver diseases.

A hemangioma is a benign (noncancerous) vascular tumor or growth that originates from blood vessels. It is characterized by an overgrowth of endothelial cells, which line the interior surface of blood vessels. Hemangiomas can occur in various parts of the body, but they are most commonly found on the skin and mucous membranes.

Hemangiomas can be classified into two main types:

1. Capillary hemangioma (also known as strawberry hemangioma): This type is more common and typically appears during the first few weeks of life. It grows rapidly for several months before gradually involuting (or shrinking) on its own, usually within the first 5 years of life. Capillary hemangiomas can be superficial, appearing as a bright red, raised lesion on the skin, or deep, forming a bluish, compressible mass beneath the skin.

2. Cavernous hemangioma: This type is less common and typically appears during infancy or early childhood. It consists of large, dilated blood vessels and can occur in various organs, including the skin, liver, brain, and gastrointestinal tract. Cavernous hemangiomas on the skin appear as a rubbery, bluish mass that does not typically involute like capillary hemangiomas.

Most hemangiomas do not require treatment, especially if they are small and not causing any significant problems. However, in cases where hemangiomas interfere with vital functions, impair vision or hearing, or become infected, various treatments may be considered, such as medication (e.g., corticosteroids, propranolol), laser therapy, surgical excision, or embolization.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults. It originates from the hepatocytes, which are the main functional cells of the liver. This type of cancer is often associated with chronic liver diseases such as cirrhosis caused by hepatitis B or C virus infection, alcohol abuse, non-alcoholic fatty liver disease (NAFLD), and aflatoxin exposure.

The symptoms of HCC can vary but may include unexplained weight loss, lack of appetite, abdominal pain or swelling, jaundice, and fatigue. The diagnosis of HCC typically involves imaging tests such as ultrasound, CT scan, or MRI, as well as blood tests to measure alpha-fetoprotein (AFP) levels. Treatment options for Hepatocellular carcinoma depend on the stage and extent of the cancer, as well as the patient's overall health and liver function. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or liver transplantation.

Alpha-fetoprotein (AFP) is a protein produced by the yolk sac and the liver during fetal development. In adults, AFP is normally present in very low levels in the blood. However, abnormal production of AFP can occur in certain medical conditions, such as:

* Liver cancer or hepatocellular carcinoma (HCC)
* Germ cell tumors, including non-seminomatous testicular cancer and ovarian cancer
* Hepatitis or liver inflammation
* Certain types of benign liver disease, such as cirrhosis or hepatic adenomas

Elevated levels of AFP in the blood can be detected through a simple blood test. This test is often used as a tumor marker to help diagnose and monitor certain types of cancer, particularly HCC. However, it's important to note that an elevated AFP level alone is not enough to diagnose cancer, and further testing is usually needed to confirm the diagnosis. Additionally, some non-cancerous conditions can also cause elevated AFP levels, so it's important to interpret the test results in the context of the individual's medical history and other diagnostic tests.

... such as an arteriovenous fistula) or innate (such as the arteriovenous shunt of a metarteriole); and it may be natural (such as ... Surgical anastomosis techniques include Linear Stapled Anastomosis, Hand Sewn Anastomosis, End-to-End Anastomosis (EEA). ... Studies have been performed comparing various anastomosis approaches taking into account surgical "time and cost, postoperative ... Surgical anastomosis occurs when segments of intestine, blood vessel, or any other structure are connected together surgically ...
... arteriovenous shunt, surgical MeSH E04.035.188 - cerebrospinal fluid shunts MeSH E04.035.188.850 - ventriculoperitoneal shunt ... peritoneovenous shunt MeSH E04.035.760 - portasystemic shunt, surgical MeSH E04.035.760.755 - portacaval shunt, surgical MeSH ... portasystemic shunt, surgical MeSH E04.100.814.790.790 - portacaval shunt, surgical MeSH E04.100.814.790.830 - portasystemic ... arteriovenous shunt, surgical MeSH E04.100.814.200 - blood vessel prosthesis implantation MeSH E04.100.814.300 - cerebral ...
It is associated with amputees, haemodialysis (HD) patients with arteriovenous (AV) shunts, and patients with paralysed legs, ... Management includes compression therapy, wound care and surgical correction of AVM. Dapsone combined with leg elevation and ...
In 1960 the use of a subcutaneous arteriovenous shunt along with the artificial kidney machine allowed hemodialysis for ... The surgical replacement of body parts also became possible and was used to treat ailing kidneys and joints such as knees and ... In 1962, in the US, Dow Corning developed the silicone gel-filled breast implant which was used by women for surgical breast ... Children were also often on the receiving end of the tonsillectomy a fashionable surgical procedure during these years. ...
Arteriovenous subpapillary plexus shunting also occurs. Persistent vasoconstriction at the precapillary sphincter creates a ... There is no standard medical or surgical treatment for acrocyanosis, and treatment, other than reassurance and avoidance of ...
2013). "Spinal dural arterio-venous fistula: clinico-radiological profile and outcome following surgical occlusion in an Indian ... If the myelogram is positive, angiography is required to show the extent of malformation and the exact site of the shunt. ... Spinal arteriovenous malformations are the main cause and are represented later in this article. However, TIAs can result from ... Surgical occlusion has been shown to halt the progression and may improve any gait or incontinence. Foix-Alajouanine syndrome ...
It often presents in infancy with cardiac failure because of extensive arteriovenous shunting within the lesion. It is the ... Surgical resection, radiotherapy, and chemotherapy have all been used to treat these masses, although studies on survival have ... Surgical resection, partial hepatectomy, and embolization of afferent vessels should be considered for severe cases. Low power ... indicating significant shunting, is seen on angiograms. Because most hemangioendotheliomas in infants sponanteously involute ...
... and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting. In the retina, the ... Patients with intracranial lesions have been treated with surgical intervention and in some cases, this procedure has been ... and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting. The facial features ... Bonnet-Dechaume-Blanc syndrome results from arteriovenous malformations. The exact cause of this disorder is unknown, and no ...
However, it can also be used to detect other forms of right-to-left shunts including pulmonary arteriovenous malformations ... Surgical closure of a patent foramen ovale or other atrial septal defects is often done through an out-patient, percutaneous, ... The use of MRI to detect cardiac shunts is "controversial" and that the use of CT is not recommended due to exposure to ... Similar to a TEE, a transcranial Doppler sonography study is also described as helping to evaluate for right-to-left shunts of ...
He did his surgical training at Cook County Hospital in Chicago. Fabian Udekwu was the first fully certified cardiothoracic ... Traumatic aneurysms and arteriovenous fistulas in Nigeria. Clinical aspects of pulmonary and pleural carcinoma in Nigeria. ... Odeku, E. L.; Antia, A. U.; Udekwu, F. A. O. (1970). "Persistent ascites following infected ventriculoperitoneal shunt". West ... Anyanwu, CH; Ude, AC; Swarup, AS; Umerah, BC; Udekwu, FA (August 1980). "Traumatic aneurysms and arteriovenous fistulas in ...
Larger arteriovenous shunts correlate with greater hemodynamic effects and earlier symptom onset; small arteriovenous shunts ... Even after surgical treatment, the mortality rate remains as high as 39.4%. Most cases occur during infancy when the mortality ... The heart failure is due to the size of the arteriovenous shunt that can steal 80% or more of the cardiac output, with large ... The Arteriovenous Malformation Study Group (June 10, 1999). "Arteriovenous Malformations of the Brain in Adults". New England ...
If bubbles appear in the left heart, it may indicate a shunt, such as a patent foramen ovale, atrial septal defect, ventricular ... Anesthesiologists can perform intra-operative TEEs during surgical cases and they interpret their own studies. Anyone ... septal defect or arteriovenous malformations in the lungs. If a doctor deems it necessary, a stress TTE may be performed. It ... for diastolic function Agitated saline bubble study for right to left shunting (PFO, ASD, VSD) With contrast, apical and mural ...
Arteriovenous fistula Sundt, Thoralf M.; Piepgras, David G. (1983-07-01). "The surgical approach to arteriovenous malformations ... MRIs are typically normal but can identify venous hypertension as a result of arterial-venous shunting. The Borden ... Type Ia - simple dural arteriovenous fistulas have a single meningeal arterial supply Type Ib - more complex arteriovenous ... Type I dural arteriovenous fistulas are supplied by meningeal arteries and drain into a meningeal vein or dural venous sinus. ...
... resulting in shunting of blood. This results in improperly oxygenated blood. (I67.1) Cerebral arteriovenous fistula, acquired ( ... For example, surgical treatment of fistulae in Crohn's disease can be effective, but if the Crohn's disease itself is not ... Coronary arteriovenous fistula, acquired (I28.0) Arteriovenous fistula of pulmonary vessels Pulmonary arteriovenous fistula: ... Surgical and medical treatment: Complications from gallbladder surgery can lead to biliary fistulas. As well as being ...
Surgical approaches to dissections can include reconstructing the aorta, surgical bypass and surgical fenestration. Like other ... The arteriovenous fistula (AVF) is the preferred method. Arteriovenous fistula are created surgically by directly connecting an ... A transjugular intrahepatic portosystemic shunt (TIPS) is a procedure an interventional radiologist performs to create a shunt ... European Journal of Surgical Oncology: The Journal of the European Society of Surgical Oncology and the British Association of ...
In the brain a cerebral arteriovenous malformation causes arterial blood to be directly shunted into the veins as there is an ... Chen, RJ; Vrazas, JI; Penington, AJ (January 2021). "Surgical Management of Intramuscular Venous Malformations". Journal of ... Those involving the mix of vessels are known as cerebral arteriovenous malformations (AVMs or cAVMs). The arteriovenous type is ... There are also malformations that are of mixed-flow involving more than one type of vessel, such as an arteriovenous ...
It accounts for 10 to 15% of intracranial arteriovenous shunts. DAVF lacks a nidus. Signs and symptoms of DAVF are: headache, ... Therefore, large EDH requires emergent surgical clot evacuation. Embolisation of middle meningeal artery is performed if the ... Dural arteriovenous fistulae (DAVF) is the direct connection between dural or cerebral arteries with dural venous sinuses or ... Cerebral ateriovenous malformation (Cerebral AVM) is characterised by abnormal shunting between cerebral arteries and veins ...
A dental cone beam scan offers useful information when it comes to the assessment and planning of surgical implants. The ... Vascular Anomalies: After correction of arteriovenous malformations with coiling, CBCT sensitively detects small infarcts in ... tissue that has been "sacrificed" during the procedure to prevent further shunting. The infarcted tissue appears as a small ... ability to combine 3 dimensional and weight bearing information which are of the utmost importance in diagnosis and surgical ...
If a source of bleeding can be identified (sources are frequently not found), then surgical correction of the bleeding source ... The chronic bleeding can come from many sources such as from an arteriovenous malformation or cavernous malformation, ... myxopapillary ependymoma of the spinal cord, from chronic subdural hematoma, from a ventricular shunt, or from chronic ...
Tortuosity is caused by arteriovenous shunting from the retinal periphery. It can feature small bleeds of the retina known as ... Surgical intervention is indicated for severely advanced disease that poses a threat to visual acuity. Indications include ... Scleral buckle was a previously popular surgical intervention however, its complications include anterior segment ischemia as a ...
"The effect of embolization with N-butyl cyanoacrylate prior to surgical resection of cerebral arteriovenous malformations". ... leading to a right-to-left blood shunt. They have no symptoms in up to 29% of all cases, however they can give rise to serious ... "Arteriovenous Malformations". Neurosurgery. Retrieved June 26, 2023. "A Randomized Trial of Unruptured Brain Arteriovenous ... An arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. ...
Surgical Neurology International, its successor publication, was also headed by James I. Ausman, M.D., editor-in-chief. Faria ... Faria MA Jr; O'Brien MS; Tindall GT (1980). "A technique for the evaluation of ventricular shunts using Amipaque and ... Schlachter LB, Fleischer AS, Faria MA Jr, Tindall GT (November 1980). "Multifocal Intracranial Arteriovenous Malformations". ... Faria completed his surgical internship at Shands Teaching Hospital at the University of Florida (1977-1978), and his ...
Deviations from the above described behavior can occur in arterialized hemangiomas or those containing arterio-venous shunts. ... Also they are successfully applied in the treatment of liver metastases, where surgical resection is contraindicated. They are ... the presence of arterio-arterial and arterio-venous shunts, lack or incompetence of arterial precapillary sphincter made up of ... surgical resection, local ablative therapies) continuing ultrasound screening is recommended first at 1 month then at 3 months ...
... soft-tissue mass usually without direct arteriovenous shunting. On MRI, IHs show a well-circumscribed lesion with intermediate ... Surgical excision of hemangiomas is rarely indicated, and limited to lesions which fail medical therapy (or when it is ... may leave behind stretched skin or fibrofatty tissue that may be disfiguring or require future surgical correction. Areas of ...
Intrapulmonary arteriovenous shunts are dormant capillaries within the lungs that become recruited when venous pressures become ... Common Surgical Diseases (2nd ed.). Springer. pp. 391-394. ISBN 978-0-387-75245-7. (CS1 maint: location missing publisher, ... In general, a shunt may be within the heart or lungs, and cannot be corrected by administering oxygen alone. Shunting may occur ... Shunting also occurs by the smallest cardiac veins, which empty directly into the left ventricle. Physiological shunts, occur ...
Comparative study oftwo surgical techniques in the treatment of varicose veins of the lower extremities: results after five ... In 1980 he described the Fistula Flow Ratio (French 'RDF') to assess the flow of arteriovenous fistulas, especially in renal ... Dynamic fractionizing of hydrostatic pressure, close and open shunt, vicarious varicose evolution: how have these concepts made ... P.Zamboni et al.: Minimally Invasive Surgical management of primary venous Ulcer vs. Compression. Eur J vasc Endovasc Surg 00,1 ...
... opening of arteriovenous shunts, all of which then worsens the condition in a vicious cycle. Swollen legs, feet and ankles are ... Timby, Barbara Kuhn; Smith, Nancy E. (2006). Introductory Medical-Surgical Nursing (9th ed.). Philadelphia: Lippincott Williams ...
Vascular shunt A vascular shunt can also bypass the capillary bed and provide a route for blood supply directly to a collecting ... An irregular connection between an artery and a vein is known as arteriovenous fistula. A small specialised arteriovenous ... ISBN 978-1-4160-6257-8. Sureka, Binit (15 September 2015). "Portal vein variations in 1000 patients: surgical and radiological ... A subcutaneous venous plexus is continuous, and a high rate of flow is supplied by small arteriovenous anastomoses. The high ...
Singh S, Taylor MA (August 2010). "Con: the FloTrac device should not be used to follow cardiac output in cardiac surgical ... Tanke RB, van Heijst AF, Klaessens JH, Daniels O, Festen C (January 2004). "Measurement of the ductal L-R shunt during ... is also known as the arteriovenous oxygen difference.[citation needed] While considered to be the most accurate method of ... It is used for managing fluid optimisation in high-risk surgical or critically ill patients. A physiologic optimization program ...
The Atrial switch operation is an alternative surgical option when the arterial switch is not feasible due to the particular ... Transposed vessels can present with atriovenous, ventriculoarterial and/or arteriovenous discordance. The effects may range ... the most common type being intracardiac shunts such as atrial septal defect including patent foramen ovale, ventricular septal ...
"Arteriovenous Shunt, Surgical" by people in this website by year, and whether "Arteriovenous Shunt, Surgical" was a major or ... "Arteriovenous Shunt, Surgical" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ( ... Arteriovenous Shunt, Surgical*Arteriovenous Shunt, Surgical. *Surgical Arteriovenous Shunt. *Shunt, Surgical Arteriovenous ... Below are the most recent publications written about "Arteriovenous Shunt, Surgical" by people in Profiles. ...
Arteriovenous Shunt, Surgical * Calcium / blood * Cardiovascular Diseases / mortality * Female * Fractures, Bone / mortality ...
No arteriovenous shunting occurs in these tumors. Angiograms clearly delineate the feeding and draining vessels; these findings ... Prokopienko M, Kunert P, Podgórska A, Marchel A. Surgical treatment of sporadic and von Hippel-Lindau syndrome-associated ... Berenstein A, Lasjaunias P. Surgical Neuroangiography: Endovascular Treatment of Spine and Spinal Cord Lesions. New York, NY: ... One study reported on the use of intraoperative indocyanine green (ICG) videoangiography during surgical resection of spinal ...
... such as an arteriovenous fistula) or innate (such as the arteriovenous shunt of a metarteriole); and it may be natural (such as ... Surgical anastomosis techniques include Linear Stapled Anastomosis, Hand Sewn Anastomosis, End-to-End Anastomosis (EEA). ... Studies have been performed comparing various anastomosis approaches taking into account surgical "time and cost, postoperative ... Surgical anastomosis occurs when segments of intestine, blood vessel, or any other structure are connected together surgically ...
Intracranial dural arteriovenous fistulas: a review of their current management based on emerging knowledge - Journal of ... KEY WORDS: Brain vascular malformations - Dural arteriovenous fistula - Surgical arteriovenous shunt - Therapeutic embolization ... Intracranial dural arteriovenous fistulas: a review of their current management based on emerging knowledge. J Neurosurg Sci ... Intracranial dural arteriovenous fistulas: a review of their current management based on emerging knowledge. Francesco ...
... dural arteriovenous shunts) can include certain medications or surgery. A surgical procedure known as sinus wall reconstruction ...
Investigations on the Filter Capacity of the Dogs Brain: A Contribution to the Question of Cerebral Arteriovenous Shunts. ... A Contribution to the Question of Cerebral Arteriovenous Shunts. Arch Neurol. 1972;26(6):479-488. doi:10.1001/archneur. ... The presence in the dogs brain of arteriovenous connections much larger than capillaries, but not larger than 76μ, is ... Surgical Innovation. *Surgical Pearls. *Teachable Moment. *Technology and Finance. *The Art of JAMA ...
Third, various cerebrovascular diseases that are associated with arteriovenous shunts, foremost pial AVMs, may produce similar ... TR 3D MRA is obtained before and after surgical exclusion of a high-grade DAVF (type 4) on a left medial tentorial sinus. The ... The type of shunt (direct cortical drainage versus shunt into a dural venous sinus), and signs of venous hypertension ( ... Venous drainage was analyzed with regard to the type of arteriovenous shunt (see above), and signs of venous hypertension ( ...
Arteriovenous Shunt, Surgical , Profiles RNS. Arteriovenous Shunt, Surgical [E04.035.087]. *Cardiovascular Surgical Procedures ... "Arteriovenous Shunt, Surgical" by people in this website by year, and whether "Arteriovenous Shunt, Surgical" was a major or ... Surgical shunt allowing direct passage of blood from an artery to a vein. (From Dorland, 28th ed) ... "Arteriovenous Shunt, ... Cardiovascular Surgical ProceduresSurgical Procedures, OperativeSurgical Procedures, MinorTreatment OutcomeAmbulatory Surgical ...
Pulmonary arteriovenous shunting in the normal fetal lung JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY McMullan, D. M., Hanley ... Clinically significant pulmonary arteriovenous malformations occur in up to 25% of patients after surgical intervention. ... Pulmonary arteriovenous shunting was not present in animals studied at four weeks of life (n = 2) and in adult sheep (n = 5). ... Pulmonary arteriovenous shunting was identified by contrast echocardiography in all surviving animals (n = 40) following ...
Arteriovenous Fistula/Shunt. 1. 2. 3. 4. 3 Way Catheter & Bladder Irrigation. 1. 2. 3. 4. ...
T82.2 Complication of mechanical origin associated with coronary artery bypass graft: Obliteration of arteriovenous shunt ... Surgical practice; The surgical procedure; Surgical interventions; Surgery on the gastrointestinal tract; Surgical procedures ... Surgical intervention of the genitourinary system; Surgical procedures on the heart; Surgical manipulation; surgery; Surgery on ... Surgical infection; Surgical treatment of chronic limb ulcers; Surgery; The surgery in the anal area; The surgery on the colon ...
Read more about how UPMC was the first institution to use the endoscopic endonasal approach to remove an arteriovenous ... The patient underwent a three-stage surgical intervention to resect the AVM. An open subfrontal approach, as the first ... Postoperative angiography revealed minimal residual shunting in the pharynx and cavernous sinus. The patient has been free of ... Ear Nose Throat J. 70:373-375;(1991), Malik GM, Mahmood A, Mehta BA Dural arteriovenous malformation of the skull base with ...
A surgical arteriovenous shunt was created in adult male Sprague-Dawley rats to induce HF. RVLM-C1 neurons were selectively ... A surgical arteriovenous shunt was created in adult male Sprague-Dawley rats to induce HF. RVLM-C1 neurons were selectively ... A surgical arteriovenous shunt was created in adult male Sprague-Dawley rats to induce HF. RVLM-C1 neurons were selectively ... A surgical arteriovenous shunt was created in adult male Sprague-Dawley rats to induce HF. RVLM-C1 neurons were selectively ...
Hemangioblastoma of filum terminale associated with arteriovenous shunting. Journal:Surgical Neurology. Wong, GKCZhu, XLNg, HK ...
Arteriovenous Shunt, Surgical. *Ascites. *Benchmarking. *Bile Duct Neoplasms. *Bile Ducts, Intrahepatic. *Boston ...
Arteriovenous Anastomosis. *Arteriovenous Fistula. *Arteriovenous Shunt, Surgical. *Cardiovascular System. *Carotid Arteries. * ...
View other providers who treat Removal of Arteriovenous Shunt for Renal Dialysis ... Vascular & Surgical Care Northwest Pllc 515 Minor Ave Ste 240, Seattle, WA 98104 ... View other providers who treat Revision of Arteriovenous Shunt for Renal Dialysis ... Removal of Arteriovenous Shunt for Renal Dialysis ... Revision of Arteriovenous Shunt for Renal Dialysis ...
The hormonal agents produced during adolescence, maternity as well as menopause can produce Arterio-Venous shunts. Researchers ... Surgical procedure can be made use of to deal with serious varicose veins. This strategy is called vein stripping. This is ... Venous shunts can damage the blood vessel walls due to the fact that it assists bypass the veins, which maintains the ... This surgical treatment entails placing an adaptable carry out with the varicose blood vessel. When the implement is taken out ...
However, large hemangiomas occasionally cause arteriovenous shunting sufficient to cause heart failure and sometimes ... If the adenoma does not regress or if it is subcapsular or > 5 cm, surgical resection is often recommended. ... surgical removal, selective hepatic artery embolization, and, rarely, liver transplantation Liver Transplantation Liver ...
We treated a 64-year-old man who had an inferior mesenteric arteriovenous malformation with multiple shunts. As multiple ... Complete surgical resection was effective treatment for this CEH.. Asunto(s). Hepatopatías , Drenaje , Hematoma/diagnóstico por ... The likely cause was a pressure increase in the incompletely thrombosed varicosity due to shunt blood flow from the remaining ... Two days after embolization, a varicosity near the shunt (65 mm diameter) ruptured, causing intra-abdominal hemorrhage and ...
Arteriovenous Shunt, Surgical. Surgical shunt allowing direct passage of blood from an artery to a vein. (From Dorland, 28th ed ... Portasystemic Shunt, Surgical. Surgical venous shunt between the portal and systemic circulation to effect decompression of the ... InterventionalArteriovenous Shunt, SurgicalAngioplasty, BalloonAnastomosis, SurgicalTreatment OutcomeCatheterization ... Anastomosis, Surgical. Surgical union or shunt between ducts, tubes or vessels. It may be end-to-end, end-to-side, side-to-end ...
Spinal dural arteriovenous fistulas (SDAVFs) result from abnormal vascular shunting between one radicular artery or arteries to ... The artery of Adamkiewicz: vascular anatomy, clinical significance and surgical considerations. Int J Cardiovasc Res. 2016;5(6 ... Spinal dural arteriovenous fistulas. AJNR Am J Neuroradiol. 2009;30(4):639-648. ... Spinal dural arteriovenous fistulas. AJNR Am J Neuroradiol. 2009;30(4):639-648. ...
What is an arteriovenous graft? An arteriovenous graft is another form of dialysis access, which can be used when people do not ... The surgical incision is usually only 2 to 4 inches long. Generally you are able to return home later that same day. The ... An AV fistula is a surgically placed "shunt"; that is, an artery is directly sutured to a vein. An artery is a high-pressure ... Creating an AV graft is a surgical procedure, which requires a small incision at the proposed site. Surgeons sew the graft to ...
A unique mechanism of action of HBOT for preserving compromised flaps is the possibility of closing arteriovenous shunts. [61] ... After emergent surgical intervention, the patient should undergo HBOT at 2-2.5 ATA for 60-90 minutes. For the next 2-3 days, ... The extent to which the injury has affected tissues is unclear, even after surgical intervention. [67, 63, 68] HBOT is not ... 27] or accidental intravenous air injection or some surgical procedures. [33, 34, 35, 36, 37] Symptoms usually occur within ...
Arguments favouring surgical intervention are the complexity of the pulmonary AVM and the extent of these lesions, leaving ... We report on one of the youngest patients diagnosed with a pulmonary AVM causing a large right to left shunt. The indication ... AVM, arteriovenous malformation. Hereditary haemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is an ... Pulmonary arteriovenous fistula: presentation, diagnosis and treatment. World J Surg1999;23:1118-21. ...
Metastatic RCC must be differentiated from benign primary soft-tissue tumors because aggressive surgical resection is necessary ... due to an arteriovenous shunt in RCC [7] might reduce the time for Gadolinium to reach the tissue in order for it to be ... World Journal of Surgical Oncology volume 5, Article number: 88 (2007) Cite this article ... Surgical resection of metastatic RCC reportedly improves the outcome of patients with metastatic RCC, and five-year survival ...
... hemodialysis patients with arteriovenous shunts, shunts for hydrocephalus, oral surgical or operative procedures (depending on ...

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