Transjugular Intrahepatic Stent Shunt Research Articles

A novel fiber-optic pressure sensor device for measuring variceal pressure.

It has been reported that variceal pressure can predict the occurrence of variceal bleeding. However, the majority of methods presently used to measure variceal pressure are either invasive or inconvenient. In the present study, a fiber-optic pressure sensor was constructed to detect variceal pressure. The prospective study focused on the in vitro accuracy of a fiber-optic pressure sensor and investigated the clinical reliability and feasibility of this method. The fiber-optic pressure sensor covered a pressure-sensitive probe containing a fiber-optic pressure sensor and a workstation to record the pressure tracing. It was hypothesized that the endoscopic fiber-optic pressure sensor can effectively predict the risk of variceal bleeding. To test this hypothesis, 80 patients who suffered from cirrhosis and who had a history of variceal bleeding were included in the present study. The fiber-optic pressure sensor was guided through the biopsy channel using an endoscope in the patient cohort. Transjugular intrahepatic stent-shunt (TIPS) was subsequently performed within 24 h after measuring variceal pressure. A comparison of the results of the 80 patients was made between variceal pressure measured by the endoscopic fiber-optic pressure sensor and the portal pressure gradient (PPG) measured by a TIPS. The variceal pressure measurements with the fiber-optic pressure sensor were technically satisfactory in 78 patients. The results indicated that there was a linear correlation between the variceal pressure measured by the endoscopic fiber-optic pressure sensor and the PPG (r=0.940, P<0.001). These observations suggest that the fiber-optic pressure sensor is an accurate and feasible measurement technique. Therefore, the results of the present study indicate that the endoscopic fiber-optic pressure sensor is effective in predicting the risk of variceal bleeding.

Hepatorenal syndrome: role of the transjugular intrahepatic stent shunt in real life practice.

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Splanchnic Vein Thrombosis

Splanchnic vein thrombosis includes thrombosis of the hepatic venous system (Budd-Chiari syndrome) and thrombosis of the portal venous system. Both conditions share uncommon prothrombotic disorders as causal factors, among which myeloproliferative neoplasms rank first. Budd-Chiari syndrome presents with acute or chronic, asymptomatic or severe liver disease. Diagnosis depends on noninvasive imaging of the obstructed hepatic venous outflow tract. A spontaneously fatal course can be prevented by a stepwise approach: (1) anticoagulation therapy, specific therapy for underlying disease, and medical or endoscopic management of liver-related complications, (2) angioplasty/stenting in a second step, and (3) eventually the insertion of transjugular intrahepatic stent shunt or liver transplantation. Recent portal vein thrombosis mostly jeopardizes the gut. Early anticoagulation prevents thrombus extension but is incompletely successful in achieving recanalization. Chronic portal vein thrombosis is complicated by bleeding related to portal hypertension, which can be prevented by usual pharmacological and endoscopic means. The prevention of recurrent thrombosis is achieved by anticoagulation therapy the impact of which on the risk of bleeding remains unclear. Portal vein thrombosis in patients with cirrhosis is likely neither a direct consequence of nor a direct cause for liver disease progression. Therefore, the indications and effects of anticoagulation therapy for portal vein thrombosis in patients with cirrhosis remain uncertain.

Acute endotoxemia following transjugular intrahepatic stent-shunt insertion is associated with systemic and cerebral vasodilatation with increased whole body nitric oxide production in critically ill cirrhotic patients

Transjugular intrahepatic stent-shunt (TIPSS) insertion, in patients with uncontrolled gastro-intestinal bleeding, often results in worsening of the systemic hemodynamics which can be associated with intracranial hypertension but the underlying mechanisms are unclear. This study explored the hypothesis that TIPSS insertion results in acute endotoxemia which is associated with increased nitric oxide production resulting in systemic and cerebral vasodilatation. Twelve patients with cirrhosis who were undergoing TIPSS for uncontrolled variceal bleeding were studied prior to and 1-h after TIPSS insertion. Changes in cardiac output (CO) and cerebral blood flow (CBF) were measured. NO production was measured using stable isotopes using l-[guanidino-(15)N(2)] arginine and l-[ureido-(13)C;5,5-(2)H(2)] citrulline infusion. The effect of pre- and post-TIPSS plasma on nitric oxide synthase (NOS) activity on human endothelial cell-line (HUVEC) was measured. TIPSS insertion resulted in a significant increase in CO and CBF. Endotoxin and induced neutrophil oxidative burst increased significantly without any significant changes in cytokines. Whole body NO production increased significantly and this was associated with increased iNOS activity in the HUVEC lines. The change in NO production correlated with the changes in CO and CBF. Brain flux of ammonia increased without significant changes in arterial ammonia. In conclusion, the insertion of TIPSS results in acute endotoxemia which is associated with increased nitric oxide production possibly through an iNOS dependent mechanism which may have important pathophysiological and therapeutic relevance to understanding the basis of circulatory failure in the critically ill cirrhotic patient.

Impact of Hospital and Surgeon Volumes in the Management of Complicated Portal Hypertension: Review of a Statewide Database in Florida

Mortality after complex surgical procedures has been shown to be inversely related to hospital volume. The purpose of this study was to determine whether these findings are applicable to radiologic and surgical procedures for complicated portal hypertension. The Agency for Healthcare Administration for the State of Florida database was queried to determine outcomes after transjugular intrahepatic stent shunts (TIPS) or surgical shunts from 2000 to 2003. A total of 1486 patients underwent either TIPS (1321) or surgical shunts (165). Natural breakpoints occurred at two and six procedures per year were correlated with survival for surgical shunts but not TIPS. Overall mortality was not different between TIPS and surgical shunts (11.0 vs. 12.7%, P = 0.51); however, the cost of TIPS was significantly lower (62,000 +/- 58.5 vs. 107,000 +/- 97.8, P < 0.001) as well as the length of hospitalization (9 +/- 9.0 days vs. 15 days +/- 12.6 days, P < 0.001). Surgical procedures for complicated portal hypertension are rapidly being replaced by TIPS. Like with other complex procedures, outcomes are related to hospital volume.

Liver disease induced by radioembolization of liver tumors

To the authors' knowledge, liver damage after liver radioembolization with yttrium90-labeled microspheres has never been studied specifically. Using a complete set of data recorded prospectively among all patients without previous chronic liver disease treated by radioembolization at the authors' institution from September 2003 to July 2006, patterns of liver damage were identified and possible risk factors were analyzed. In all, 20% of patients developed a distinct clinical picture that appeared 4 to 8 weeks after treatment and was characterized by jaundice and ascites. Veno-occlusive disease was the histologic hallmark observed in the most severe cases. This form of sinusoidal obstruction syndrome was not observed among patients who never received chemotherapy or in those in whom a single hepatic lobe was treated. Relevant to treatment planning, a possible risk factor was a higher treatment dose in relation to the targeted liver volume. A transjugular intrahepatic stent shunt improved liver function in 2 patients with impending liver failure, although 1 of them eventually died from it. Radioembolization of liver tumors, particularly after antineoplastic chemotherapy, may result in an uncommon but potentially life-threatening form of hepatic sinusoidal obstruction syndrome that presents clinically with jaundice and ascites.

Kidney plays a major role in ammonia homeostasis after portasystemic shunting in patients with cirrhosis

The kidney plays an important role in ammonia metabolism. In this study the hypothesis was tested that the kidney can acutely diminish ammonia release after portacaval shunting. Thirteen patients with cirrhosis (6 female/7 male, age 54.4 +/- 3.3 yr) were studied. Blood was sampled prior to and 1 h after transjugular intrahepatic stent-shunt (TIPSS) insertion from the portal vein, a hepatic vein, the right renal vein, and the femoral vein, and renal and liver plasma flow were measured. Prior to TIPSS, renal ammonia release was significantly higher than ammonia release from the splanchnic region, which was not significantly different from zero. TIPSS insertion did not change arterial ammonia concentration or ammonia release from the splanchnic region but reduced renal ammonia release into the circulation (P < 0.05) to values that were not different from zero. TIPSS resulted in a tendency toward increased venous-arterial ammonia concentration differences across leg muscle. Post-TIPSS ammonia efflux via portasystemic shunts was estimated to be seven times higher than renal efflux. Kidneys have the ability to acutely diminish systemic ammonia release after portacaval shunting. Diminished renal ammonia release and enhanced muscle ammonia uptake are important mechanisms by which the cirrhotic patient maintains ammonia homeostasis after portasystemic shunting.

Radiologic after-care of transjugular intrahepatic stent shunt (TIPSS)]

The transjugular intrahepatic stent-shunt (TIPSS) is a well accepted minimal invasive therapy for complications of portal hypertension: recurrent variceal bleeding, refractory ascites and liver failure due to the Budd-Chiari syndrome. The high frequency of shunt stenoses and occlusions makes regular follow up examinations essential. Despite modern non invasive imaging methods direct portography still is the gold standard for shunt surveillance in TIPSS. Ultrasound is helpful to detect shunt dysfunction, but nevertheless its failure rate is considerable despite the use of contrast enhancers such as Levovist because of anatomic and physical limitations, particularly when TIPSS-tracts deep in the liver are present. Reintervention rates approach 90-100% after 24 months, with 100% in child's A patients with comparatively good liver function. However, a strict shunt surveillance program with early portography and reintervention when necessary guarantees high clinical success rates associated with very low rebleeding rates below 10%. Overall the secondary success rate is 80%. Secondary failures are mainly caused by lack of patient compliance during follow-up. In a subgroup of patients no shunt maturation is observed, requiring multiple shunt revisions. In cases of recurrent shunt occlusions an association with bile leaks is presumed. In selected cases patients with chronically recurrent shunt stenosis or occlusions may benefit from placement of TIPSS stent grafts.