Feasibility and long-term evolution of TIPS in cirrhotic patients with portal thrombosis

Managing complications in cirrhotic patients

Liver cirrhosis is a serious and potentially life-threatening condition. This life-threatening condition usually arises from complications of cirrhosis. While variceal bleeding is the most acute and probably best studied, several other complications of liver cirrhosis are more insidious in their onset but nevertheless more important for the long-term management and outcome of these patients. This review summarizes the topics discussed during the UEG-EASL Hepatology postgraduate course of the United European Gastroenterology Week 2013 and discusses emergency surgical conditions in cirrhotic patients, the management of hepatic encephalopathy, ascites and hepatorenal syndrome, coagulation disorders, and liver cancer.

Volumetric blood flow in transjugular intrahepatic portosystemic shunt revision using 3-dimensional Doppler sonography

OBJECTIVES

Three-dimensional (3D)/4-dimensional (4D) sonographic measurement of blood volume flow in transjugular intrahepatic porto systemic shunt revision with the intention of objective assessment of shunt patency.

METHODS

A total of 17 patients were recruited (12 male and 5 female; mean age, 55 years; range, 30-69 years). An ultrasound system equipped with a 2.0-5.0-MHz probe was used to acquire multivolume 3D/4D color Doppler data sets to assess prerevision and postrevision shunt volume flow. Volume flow was computed offline based on the principle of surface integration of Doppler-measured velocity vectors in a lateral-elevational c-surface positioned at the color flow focal depth (range, 8.0-11.5 cm). Volume flow was compared to routine measurements of the prerevision and postrevision portosystemic pressure gradient. Prerevision volume flow was compared with the outcome to determine whether a flow threshold for revision could be defined.

RESULTS

Linear regression of data from revised transjugular intrahepatic portosystemic shunt cases showed an inverse correlation between the mean-normalized change in prerevision and postrevision shunt volume flow and the mean-normalized change in the prerevision and postrevision portosystemic pressure gradient (r(2) = 0.51; P = .020). Increased shunt blood flow corresponded to a decreased pressure gradient. Comparison of prerevision flows showed preliminary threshold development at 1534 mL/min, below which a shunt revision may be recommended (P = .21; area under the receiver operating characteristic curve = 0.78).

CONCLUSIONS

Shunt volume flow measurement with 3D/4D Doppler sonography provides a potential alternative to standard pulsed wave Doppler metrics as an indicator of shunt function and predictor of revision.

The coagulation system in patients with end-stage liver disease

In patients with cirrhosis, routine laboratory tests for primary hemostasis and coagulation usually show anomalies that are associated with excess bleeding in other settings, in particular low platelet counts and prolonged prothrombin time. However, under conditions similar to those in vivo, primary hemostasis and thrombin production do not appear to be decreased in patients with cirrhosis, particularly when the platelet count is above 75,000/μl. Furthermore, there is laboratory and epidemiological evidence of a mild procoagulant and prothrombotic state in patients with cirrhosis. Bleeding is mainly because of portal hypertension rather than defective hemostasis. There is some evidence that anticoagulation therapy is not associated with an excess of severe bleeding and that it could improve the outcome in patients without portal vein thrombosis. At present, there is no clear evidence that portal vein thrombosis is responsible for the progression of liver disease and that anticoagulation therapy would improve the outcome of patients with portal vein thrombosis.

Portal vein thrombosis in cirrhosis

Portal vein thrombosis (PVT) is being increasingly recognized in patients with advanced cirrhosis and in those undergoing liver transplantation. Reduced flow in the portal vein is probably responsible for clotting in the spleno-porto-mesenteric venous system. There is also increasing evidence that hypercoagulability occurs in advanced liver disease and contributes to the risk of PVT. Ultrasound based studies have reported a prevalence of PVT in 10-25% of cirrhotic patients without hepatocellular carcinoma. Partial thrombosis of the portal vein is more common and may not have pathophysiological consequences. However, there is high risk of progression of partial PVT to complete PVT that may cause exacerbation of portal hypertension and progression of liver insufficiency. It is thus, essential to accurately diagnose and stage PVT in patients waiting for transplantation and consider anticoagulation therapy. Therapy with low molecular weight heparin and vitamin K antagonists has been shown to achieve complete and partial recanalization in 33-45% and 15-35% of cases respectively. There are however, no guidelines to help determine the dose and therapeutic efficacy of anticoagulation in patients with cirrhosis. Anticoagulation therapy related bleeding is the most feared complication but it appears that the risk of variceal bleeding is more likely to be dependent on portal pressure rather than solely related to coagulation status. TIPS has also been reported to restore patency of the portal vein. Patients with complete PVT currently do not form an absolute contraindication for liver transplantation. Thrombectomy or thromboendovenectomy is possible in more than 75% of patients followed by anatomical end-to-end portal anastomosis. When patency of the portal vein and/or superior mesenteric vein is not achieved, only non-anatomical techniques (reno-portal anastomosis or cavo-portal hemitransposition) can be performed. These techniques, which do not fully reverse portal hypertension, are associated with higher morbidity and mortality risks in the short term.

Management of portal vein thrombosis in liver cirrhosis

Portal vein thrombosis (PVT) is a fairly common complication of liver cirrhosis. Importantly, occlusive PVT might influence the prognosis of patients with cirrhosis. Evidence from a randomized controlled trial has shown that anticoagulation can prevent the occurrence of PVT in patients with cirrhosis without prior PVT. Evidence from several case series has also demonstrated that anticoagulation can achieve portal vein recanalization in patients with cirrhosis and PVT. Early initiation of anticoagulation therapy and absence of previous portal hypertensive bleeding might be positively associated with a high rate of portal vein recanalization after anticoagulation. However, the possibility of spontaneous resolution of partial PVT questions the necessity of anticoagulation for the treatment of partial PVT. In addition, a relatively low recanalization rate of complete PVT after anticoagulation therapy suggests its limited usefulness in patients with complete PVT. Successful insertion of a transjugular intrahepatic portosystemic shunt (TIPS) not only recanalizes the thrombosed portal vein, but also relieves the symptomatic portal hypertension. However, the technical difficulty of TIPS potentially limits its widespread application, and the risk and benefits should be fully balanced. Notably, current recommendations regarding the management of PVT in liver cirrhosis are insufficient owing to low-quality evidence.

When and why portal vein thrombosis matters in liver transplantation: a critical audit of 174 cases

OBJECTIVE

To identify complications associated with different techniques utilized to treat portal vein thrombosis (PVT) during primary liver transplantation and their impact on survival.

BACKGROUND

PVT remains an intricate problem in liver transplantation, and the long-term outcomes of patients with PVT who undergo transplantation are not well defined.

METHODS

We performed a retrospective cohort analysis of all consecutive adult patients who underwent primary isolated liver transplantation from 1998 to 2009 (median follow-up period, 89 months). The outcomes of patients with PVT were compared with those without PVT.

RESULTS

Among 1379 recipients, 174 (12.6%) had PVT at the time of transplantation [83 (48%) complete and 91 (52%) partial]. Among PVT patients with reestablished physiological portal inflow (PVT: physiological group; n = 149), 123 underwent thrombectomies, 16 received interpositional vein grafts, and 10 received mesoportal jump grafts. In 25 patients, physiological portomesenteric venous circulation was not reconstituted (PVT: nonphysiological group; 18 underwent cavoportal hemitranspositions, 6 renoportal anastomoses, and 1 arterialization). The PVT: nonphysiological group suffered a significantly increased incidence of rethrombosis of the portomesenteric veins and gastrointestinal bleeding, with a marginal 10-year overall survival rate of 42% (no PVT, 61%; P = 0.002 and PVT: physiological, 55%; P = 0.043). The PVT: physiological and no PVT groups exhibited comparable survival rates (P = 0.13). No significant differences in survival were observed between complete and partial PVT as long as physiological portal flow was reestablished.

CONCLUSIONS

The subset of PVT patients requiring nonphysiological portal vein reconstruction was associated with higher complication rates and suffered diminished long-term prognoses. For the most severe PVT cases, a comprehensive approach is critical to further improve outcomes.

Transjugular intrahepatic portosystemic shunt for the treatment of portal hypertension in noncirrhotic patients with portal cavernoma

Background. The purpose of this study was to evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) placement in the management of portal hypertension in noncirrhotic patients with portal cavernoma. Methods. We conducted a single institution retrospective analysis of 15 noncirrhotic patients with portal cavernoma treated with TIPS placement. 15 patients (4 women and 11 men) were evaluated via the technical success of TIPS placement, procedural complications, and follow-up shunt patency. Results. TIPS placement was technically successful in 11 out of 15 patients (73.3%). Procedure-related complications were limited to a single instance of hepatic encephalopathy in one patient. In patients with successful shunt placement, the portal pressure gradient decreased from 25.8 ± 5.7 to 9.5 ± 4.2 mmHg (P < 0.001). TIPS dysfunction occurred in two patients during a median follow-up time of 45.2 months. Revision was not performed in one patient due to inadequate inflow. The other patient died of massive gastrointestinal bleeding in a local hospital. The remaining nine patients maintained functioning shunts through their last evaluation. Conclusions. TIPS is a safe and effective therapeutic treatment for noncirrhotic patients with symptomatic portal hypertension secondary to portal cavernoma.

Portal vein thrombosis and liver transplantation: implications for waiting list period, surgical approach, early and late follow-up

Portal vein thrombosis (PVT) is a well-known and relatively common complication of liver cirrhosis. In the past, PVT was considered as a contraindication for liver transplantation (LT). To characterize prevalence, risk factors, perioperative management and outcome of PVT in the setting of LT, the English literature published between 1991 and 2011 was reviewed. Of 6807 articles, 280 were selected, and 39 experiences were analyzed in detail (methodology, type and duration of treatments, peri-operative management, strategy to avoid recurrence, strengths and weaknesses, Oxford evidence level, citations). 3/39 studies were prospective; 9/39 were based on prospectively recorded databases; no studies of 1, 2a, 3a level of evidence were present; 5/39 were recognized as level 2b, 23/39 as level 3b, and 8/39 as level 4. High complication rate has been reported with consequent effect on graft and patient survival. Overall, PVT presents today good results similar to those obtained in patients without PVT undergoing LT even if they require a higher transfusion number and a longer ICU/hospital stay. Reported cases were retrospectively stratified according to Yerdel classification. Grade 1-2 patients (76%) do well with eversion thromboendovenectomy, resection of damaged vein and porto-portal anastomosis. Results of patients with grade 3-4 (24%) are inferior, however data on outcome in this subsets are fragmented and do not allow a reliable analysis. Moreover, results obtained in grade 3-4 cases are better in transplant centers with large specific experience. The small number of reports suggests caution. The role of anticoagulant treatment is still debated. Although in cirrhotics with PVT LT remains a demanding procedure, PVT should not be considered a contraindication anymore.

The Evolution of Transjugular Intrahepatic Portosystemic Shunt: Tips

Since Richter's description in the literature in 1989 of the first procedure on human patients, transjugular intrahepatic portosystemic shunt (TIPS) has been worldwide considered as a noninvasive technique to manage portal hypertension complications. TIPS succeeds in lowering the hepatic sinusoidal pressure and in increasing the circulatory flow, thus reducing sodium retention, ascites recurrence, and variceal bleeding. Required several revisions of the shunt TIPS can be performed in case of different conditions such as hepatorenal syndrome, hepatichydrothorax, portal vein thrombosis, and Budd-Chiari syndrome. Most of the previous studies on TIPS procedure were based on the use of bare stents and most patients chose TIPS 2-3 years after traditional treatment, thus making TIPS appear to be not superior to endoscopy in survival rates. Bare stents were associated with higher incidence of shunt failure and consequently patients required several revisions during the follow-up. With the introduction of a dedicated e-PTFE covered stent-graft, these problems were completely solved, No more reinterventions are required with a tremendous improvement of patient's quality of life. One of the main drawbacks of the use of e-PTFE covered stent-graft is higher incidence of hepatic encephalopathy. In those cases refractory to the conventional medical therapy, a shunt reduction must be performed.

Balloon occlusion retrograde transvenous obliteration of gastric varices in two non-cirrhotic patients with portal vein thrombosis

This report describes two non-cirrhotic patients with portal vein thrombosis who underwent successful balloon occlusion retrograde transvenous obliteration (BRTO) of gastric varices with a satisfactory response and no complications. One patient was a 35-year-old female with a history of Crohn's disease, status post-total abdominal colectomy, and portal vein and mesenteric vein thrombosis. The other patient was a 51-year-old female with necrotizing pancreatitis, portal vein thrombosis, and gastric varices. The BRTO procedure was a useful treatment for gastric varices in non-cirrhotic patients with portal vein thrombosis in the presence of a gastrorenal shunt.

TIPS: 25 years later

In the 25 years since the first TIPS intervention has been performed, technical standards, indications, and contraindications have been set up. The previous considerable problem of shunt failure by thrombosis or intimal proliferation in the stent or in the draining hepatic vein has been reduced considerably by the availability of polytetrafluoroethylene (PTFE)-covered stents resulting in reduced rebleeding and improved survival. Unfortunately, most clinical studies have been performed prior to the release of the covered stent and, therefore, do not represent the present state of the art. In spite of this, TIPS has gained increasing acceptance in the treatment of the various complications of portal hypertension and vascular diseases of the liver.

Transjugular intrahepatic portosystemic shunt for the prevention of variceal rebleeding in cirrhotic patients with portal vein thrombosis: study protocol for a randomised controlled trial

INTRODUCTION

Portal vein thrombosis (PVT) increases the risk of variceal rebleeding in liver cirrhosis. However, the strategy for preventing variceal rebleeding in cirrhotic patients with PVT has not been explored. This study aims to evaluate whether the transjugular intrahepatic portosystemic shunt (TIPS) or conventional therapy is preferable for the prevention of variceal rebleeding in liver cirrhosis patients with PVT.

METHODS AND ANALYSIS

This is a randomised controlled trial comparing the safety and efficacy of TIPS versus conventional therapy (ie, endoscopic therapy combined with non-selective β-blockers and anticoagulants) for the prevention of variceal rebleeding in cirrhotic patients with non-tumoral PVT. A total of 50 cirrhotic patients with PVT (thrombus >50% of portal vein lumen occupancy) and a history of variceal bleeding will be stratified according to the Child-Pugh class and degree of PVT, and randomised into the TIPS and conventional therapy groups. The primary objective was to compare the incidence of variceal rebleeding between the two groups. The secondary objectives were to compare the overall mortality, variceal rebleeding-related mortality, portal vein recanalisation and complications between the two groups, and to observe the progression of PVT in patients without portal vein recanalisation.

ETHICS AND DISSEMINATION

This study was approved by the ethics committee of Xijing hospital (No. 20110224-5), and was registered at ClinicalTrials.gov (NCT01326949). All participants give written informed consent. The first patient was recruited into our study on 4 June 2011. A total of 29 patients were recruited through 5 March 2013 (14 and 15 patients assigned to the TIPS and conventional therapy groups, respectively). If TIPS is superior to conventional therapy for the prevention of variceal rebleeding in cirrhotic patients with PVT, TIPS might be recommended as the first-line therapy in such patients. But a small sample size potentially limits the generalisation of our conclusions.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on 29 March 2011. The trial registration number is NCT01326949.

TRIAL STATUS

The first patient was recruited into our study on 4 June 2011. A total of 29 patients were recruited through 5 March 2013 (14 and 15 patients assigned to the TIPS and conventional therapy groups, respectively).

Efficacy of transjugular intrahepatic portosystemic shunt to prevent total portal vein thrombosis in cirrhotic patients awaiting for liver transplantation

INTRODUCTION

Complete portal vein thrombosis (PVT) may complicate orthotopic liver transplantation (OLT), increasing its technical difficulty and the transfusion requirements and as well as affecting survival in some cases. Transjugular intrahepatic portosystemic shunt (TIPS) prevents total portal vein occlusion in patients with partial PVT.

OBJECTIVE

We aimed to assess the efficacy and safety of TIPS to prevent total portal vein occlusion among patients listed for OLT.

PATIENTS AND METHODS

We analyzed the clinical records of 15 consecutive patients with partial PVT who underwent TIPS before OLT. The control group consisted of 8 transplanted patients without TIPS but partial PVT diagnosed before OLT. Portal vein patency at surgery, ischemia time, and transfusion requirements during OLT, and survival thereafter were compared between both groups. The main complications were also compared: mortality after TIPS (from TIPS placement to OLT), intraoperative technical complications, and technical complications during the 6 months after OLT.

RESULTS

Clinical characteristics at the time of OLT were similar between the groups. No relevant complications were observed after TIPS; all patients underwent transplantation. One- and 5-year actuarial survival rates were similar in both groups (92% and 85% in TIPS-group versus 100 and 75% in the control group, respectively). No differences in transfusion requirement, duration of ischemia, and frequency of technical complications during and after OLT were observed between the groups. The portal vein was patent at surgery in all TIPS patients and 4 of 8 (50%) in the control group (P = .008).

CONCLUSION

TIPS may prevent PVT in liver transplantation candidates with partial PVT.

Clinical outcome and predictors of survival after TIPS insertion in patients with liver cirrhosis

AIM: To determine the clinical outcome and predictors of survival after transjugular intrahepatic portosystemic stent shunt (TIPS) implantation in cirrhotic patients.

METHODS: Eighty-one patients with liver cirrhosis and consequential portal hypertension had TIPS implantation (bare metal) for either refractory ascites (RA) (n = 27) or variceal bleeding (VB) (n = 54). Endpoints for the study were: technical success, stent occlusion and stent stenosis, rebleeding, RA and mortality. Clinical records of patients were collected and analysed. Baseline characteristics [e.g., age, sex, CHILD score and the model for end-stage liver disease score (MELD score), underlying disease] were retrieved. The Kaplan-Meier method was employed to calculate survival from the time of TIPS implantation and comparisons were made by log rank test. A multivariate analysis of factors influencing survival was carried out using the Cox proportional hazards regression model. Results were expressed as medians and ranges. Comparisons between groups were performed by using the Mann-Whitney U-test and the χ² test as appropriate.

RESULTS: No difference could be seen in terms of age, sex, underlying disease or degree of portal pressure gradient (PPG) reduction between the ascites and the bleeding group. The PPG significantly decreased from 23.4 ± 5.3 mmHg (VB) vs 22.1 ± 5.5 mmHg (RA) before TIPS to 11.8 ± 4.0 vs 11.7 ± 4.2 after TIPS implantation (P = 0.001 within each group). There was a tendency towards more patients with stage CHILD A in the bleeding group compared to the ascites group (24 vs 6, P = 0.052). The median survival for the ascites group was 29 mo compared to > 60 mo for the bleeding group (P = 0.009). The number of radiological controls for stent patency was 6.3 for bleeders and 3.8 for ascites patients (P = 0.029). Kaplan-Meier calculation indicated that stent occlusion at first control (P = 0.027), ascites prior to TIPS implantation (P = 0.009), CHILD stage (P = 0.013), MELD score (P = 0.001) and those patients not having undergone liver transplantation (P = 0.024) were significant predictors of survival. In the Cox regression model, stent occlusion (P = 0.022), RA (P = 0.043), CHILD stage (P = 0.015) and MELD score (P = 0.004) turned out to be independent prognostic factors of survival. The anticoagulation management (P = 0.097), the porto-systemic pressure gradient (P = 0.460) and rebleeding episodes (P = 0.765) had no significant effect on the overall survival.

CONCLUSION: RA, stent occlusion, initial CHILD stage and MELD score are independent predictors of survival in patients with TIPS, speaking for a close follow-up in these circumstances.

Transjugular intrahepatic portosystemic shunt may be superior to conservative therapy for variceal rebleeding in cirrhotic patients with non-tumoral portal vein thrombosis: a hypothesis

The presence of occlusive portal vein thrombosis (PVT) greatly changes the natural history of liver cirrhosis, because it not only significantly increases the incidence of variceal rebleeding but also negatively influences the survival. However, due to the absence of strong evidence, no standard treatment algorithm for the secondary prophylaxis of variceal bleeding in cirrhotic patients with non-tumoral PVT has been established. Previous randomized controlled trials have demonstrated that transjugular intrahepatic portosystemic shunt (TIPS) can significantly decrease the incidence of variceal rebleeding in cirrhotic patients without PVT, compared with conservative therapy (i.e., endoscopic plus pharmacological therapy). Further, several large cohort studies have confirmed that TIPS can effectively prevent variceal rebleeding in cirrhotic patients with non-tumoral PVT. On the other hand, TIPS can facilitate recanalizing the thrombosed portal vein by endovascular manipulations, even in the presence of cavernous transformation of the portal vein (CTPV). More importantly, successful TIPS insertions can maintain the persistent portal vein patency, and avoid thrombus extension into the portal venous system. By comparison, anticoagulation therapy can achieve portal vein recanalization only in patients with partial PVT, but not in those with occlusive PVT or CTPV, and the use of anticoagulants may aggravate the risk of variceal bleeding in cirrhotic patients with a history of variceal bleeding. Collectively, we hypothesize that TIPS may be superior to conservative therapy for the prevention of variceal rebleeding in cirrhotic patients with non-tumoral PVT. Randomized controlled trials should be conducted to evaluate the survival benefit of TIPS in these patients.

Efficacy and safety of anticoagulation on patients with cirrhosis and portal vein thrombosis

BACKGROUND & AIMS

Portal vein thrombosis (PVT) is a frequent event in patients with cirrhosis; it can be treated with anticoagulants, but there are limited data regarding safety and efficacy of this approach. We evaluated this therapy in a large series of patients with cirrhosis and non-neoplastic PVT.

METHODS

We analyzed data from 55 patients with cirrhosis and PVT, diagnosed from June 2003 to September 2010, who received anticoagulant therapy for acute or subacute thrombosis (n = 31) or progression of previously known PVT (n = 24). Patients with cavernomatous transformation were excluded. Thrombosis was diagnosed, and recanalization was evaluated by using Doppler ultrasound, angio-computed tomography, and/or angio-magnetic resonance imaging analyses.

RESULTS

Partial or complete recanalization was achieved in 33 patients (60%; complete in 25). Early initiation of anticoagulation was the only factor significantly associated with recanalization. Rethrombosis after complete recanalization occurred in 38.5% of patients after anticoagulation therapy was stopped. Despite similar baseline characteristics, patients who achieved recanalization developed less frequent liver-related events (portal hypertension-related bleeding, ascites, or hepatic encephalopathy) during the follow-up period, but this difference was not statistically significant (P = .1). Five patients developed bleeding complications that were probably related to anticoagulation. A platelet count <50 × 109/L was the only factor significantly associated with higher risk for experiencing a bleeding complication. There were no deaths related to anticoagulation therapy.

CONCLUSIONS

Anticoagulation is a relatively safe treatment that leads to partial or complete recanalization of the portal venous axis in 60% of patients with cirrhosis and PVT; it should be maintained indefinitely to prevent rethrombosis.

Portal vein thrombosis, cirrhosis, and liver transplantation

Portal vein thrombosis is not uncommon in candidates for transplantation. Partial thrombosis is more common than complete thrombosis. Despite careful screening at evaluation, a number of patients are still found with previously unrecognized thrombosis per-operatively. The objective is to recanalize the portal vein or, if recanalization is not achievable, to prevent the extension of the thrombus so that a splanchnic vein can be used as the inflow vessel to restore physiological blood flow to the allograft. Anticoagulation during waiting time and transjugular intrahepatic portosystemic shunt (TIPS) are two options to achieve these goals. TIPS may achieve recanalization in patients with complete portal vein thrombosis. However, a marked impairment in liver function, which is a characteristic feature of most candidates for transplantation, may be a contraindication for TIPS. Importantly, the MELD score is artificially increased by the administration of vitamin K antagonists due to prolonged INR. When patency of the portal vein and/or superior mesenteric vein is not achieved, only non-anatomical techniques (renoportal anastomosis or cavoportal hemitransposition) can be performed. These techniques, which do not fully reverse portal hypertension, are associated with higher morbidity and mortality risks. Multivisceral transplantation including the liver and small bowel needs to be evaluated. In the absence of prothrombotic states that may persist after transplantation, there is no evidence that pre-transplant portal vein thrombosis justifies long term anticoagulation post-transplantation, provided portal flow has been restored through conventional end-to-end portal anastomosis.

Management of hepatic vascular diseases

Primary damage to hepatic vessels is rare. (i) Hepatic arterial disorders, related mostly to iatrogenic injury and occasionally to systemic diseases, lead to ischemic cholangiopathy. (ii) Hepatic vein or inferior vena cava thrombosis, causing primary Budd-Chiari syndrome, is related typically to a combination of underlying prothrombotic conditions, particularly myeloproliferative neoplasms, factor V Leiden, and oral contraceptive use. The outcome of Budd-Chiari syndrome has markedly improved with anticoagulation therapy and, when needed, angioplasty, stenting, TIPS, or liver transplantation. (iii) Extrahepatic portal vein thrombosis is related to local causes (advanced cirrhosis, surgery, malignant or inflammatory conditions), or general prothrombotic conditions (mostly myeloproliferative neoplasms or factor II gene mutation), often in combination. Anticoagulation at the early stage prevents thrombus extension and, in 40% of the cases, allows for recanalization. At the late stage, gastrointestinal bleeding related to portal hypertension can be prevented in the same way as in cirrhosis. (iv) Sinusoidal obstruction syndrome (or venoocclusive disease), caused by agents toxic to bone marrow progenitors and to sinusoidal endothelial cells, induces portal hypertension and liver dysfunction. Decreasing the intensity of myeloablative regimens reduces the incidence of sinusoidal toxicity. (v) Obstruction of intrahepatic portal veins (obliterative portal venopathy) can be associated with autoimmune diseases, prothrombotic conditions, or HIV infection. The disease can eventually be complicated with end-stage liver disease. Extrahepatic portal vein obstruction is common. Anticoagulation should be considered. (vi) Nodular regenerative hyperplasia is induced by the uneven perfusion due to obstructed sinusoids, or portal or hepatic venules. It causes pure portal hypertension.

Transjugular intrahepatic portosystemic shunt in the treatment of portal vein thrombosis: a critical review of literature

Reports of successful transjugular intrahepatic portosystemic shunt (TIPS) surgery in patients with portal vein thrombosis (PVT) are considered anecdotal owing to the technical difficulty of the procedure and potential procedure-related complications. A literature review was undertaken to determine the feasibility and safety of TIPS in the treatment of PVT. All studies in which TIPS was attempted in patients with PVT were identified by searching through the PUBMED and MEDLINE databases. A total of 424 PVT patients undergoing TIPS were reported in 54 articles. The success rate of TIPS insertion was 67-100% in 19 case series. Further, 85 patients with portal cavernoma underwent successful TIPS insertions. Three therapeutic strategies of TIPS placement were used: (1) TIPS placement followed by portal vein recanalization via the shunt, (2) portal vein recanalization via percutaneous approaches followed by TIPS placement, and (3) TIPS insertion between a hepatic vein and a large collateral vessel without portal vein recanalization. Four approaches were used to access the portal vein: transjugular, transhepatic, transsplenic, and transmesenteric. Intra-abdominal hemorrhage secondary to hepatic capsule perforation was lethal in only three patients. No episode of pulmonary embolism was reported. Other procedure-related complications were reversible. The overall incidence of shunt dysfunction and hepatic encephalopathy was 8-33% and 0-50%, respectively. In conclusion, the reviewed studies uniformly support the feasibility and safety of TIPS for PVT even in the presence of portal cavernoma. Further, several major issues that remain unresolved are discussed.

Transjugular intrahepatic portosystemic shunt for portal cavernoma with symptomatic portal hypertension in non-cirrhotic patients

BACKGROUND

Portal cavernoma is regarded as a contraindication to transjugular intrahepatic portosystemic shunt (TIPS).

AIM

To evaluate the feasibility, safety, and efficacy of TIPS for symptomatic portal hypertension in non-cirrhotic patients with portal cavernoma.

METHODS

Between July 2002 and December 2009, 46 consecutive non-cirrhotic patients with portal cavernoma were admitted to our center. Twenty patients presented with variceal rebleeding (n = 20) and refractory ascites (n = 1), and were treated with TIPS. They were followed until either death or July 2010. Data were compared using the Fisher's exact test or t test.

RESULTS

TIPS were successfully placed in 35% (7/20) of patients via a transjugular approach alone (n = 1), a combined transjugular/transhepatic approach (n = 4), and a combined transjugular/transsplenic approach (n = 2). TIPS were inserted in a large collateral vein in two patients in whom recanalization of the occluded main portal vein was impossible. Procedure-related complication was hepatic capsule perforation in one patient who was cured by medical therapy alone. Shunt dysfunction occurred in two patients, but TIPS revision was failed in one of them. Portosystemic pressure gradient was significantly reduced in TIPS success group (26.3 ± 1.1 vs. 12.4 ± 1.1 mmHg, p < 0.001). The incidence of variceal bleeding in TIPS success group is lower than that in TIPS failure group (14 vs. 69%, p = 0.057). In TIPS success group, two patients died of systemic infection and accident, respectively. In TIPS failure group, two patients died of liver failure.

CONCLUSIONS

TIPS procedures are feasible and safe in selected patients with portal cavernoma. Successful TIPS insertions may decrease the incidence of variceal rebleeding.

Hypercoagulability in cirrhosis: causes and consequences

Decreased levels of most coagulation factors and thrombocytopenia are the main haemostatic abnormalities of cirrhosis. As a consequence, this condition was, until recently, considered as the prototype acquired coagulopathy responsible for bleeding. However, recent evidence suggests that it should, rather, be regarded as a condition associated with normal or even increased thrombin generation. The bleeding events that occur in these patients should, therefore, be explained by the superimposed conditions that frequently occur in this setting. Due to elevated levels of factor VIII (procoagulant driver) in combination with decreased protein C (anticoagulant driver), which are typically found in patients with cirrhosis, a procoagulant imbalance, defined as a partial resistance to the in vitro anticoagulant action of thrombomodulin, can be demonstrated. Whether this in vitro hypercoagulability is truly representative of what occurs in vivo remains to be established. However, the hypothesis that it may have clinical consequences is attractive and deserves attention. The possible consequences that we discuss herein include whether (i) cirrhosis is a condition associated with increased risk of venous thromboembolism or portal vein thrombosis; (ii) the hypercoagulability associated with cirrhosis has any other role outside coagulation (i.e. progression of liver fibrosis); and (iii) anticoagulation should be used in cirrhosis. Although apparently provocative, considering anticoagulation as a therapeutic option in patients with cirrhosis is now supported by a rationale of increasing strength. There may be subgroups of patients who benefit from anticoagulation to treat or prevent thrombosis and to slow hepatic fibrosis. Clinical studies are warranted to explore these therapeutic options.