Covered stents in transjugular portosystemic shunt: healing response to non-porous ePTFE covered stent grafts with and without intraluminal irradiation

Patency and clinical outcomes of transjugular intrahepatic portosystemic shunt with polytetrafluoroethylene-covered stents versus bare stents: a meta-analysis

BACKGROUND AND AIM

 Transjugular intrahepatic portosystemic shunt (TIPS) with polytetrafluoroethylene-(PTFE)-covered stent has been increasingly used for patients with complications of portal hypertension. It is still debated whether the new endoprostheses will improve some clinical outcomes (except for shunt patency) compared to the bare stents. The aims of our meta-analysis were to explore the patency and clinical outcomes of TIPS with PTFE-covered stent-grafts versus bare stents.

METHODS

Pertinent studies were retrieved through PubMed (1950-2010), MEDLINE (1950-2010), and reference lists of key articles. Outcome measures were primary patency, risk of encephalopathy and survival. Time-to-event data analysis was used to calculate the overall hazard ratios (HR).

RESULTS

Six studies were identified including a total of 1275 patients (346 TIPS with PTFE-covered stent-grafts and 929 TIPS with bare stents). Pooled shunt patency data from four eligible studies suggested a significant improvement of primary patency in patients who were treated with PTFE-covered stent-grafts (HR = 0.28, 95% confidence interval [CI] 0.20-0.35). Pooled encephalopathy data from three eligible studies suggested a significant reduction of risk in the PTFE-covered group (HR = 0.65, 95%CI 0.45-0.86). Pooled survival data from four eligible studies also suggested a significant decrease of mortality in the PTFE-covered group (HR = 0.76, 95%CI 0.58-0.94). No statistical heterogeneity was observed between studies for either outcome.

CONCLUSIONS

This meta-analysis shows that the use of PTFE-covered stent-grafts clearly improves shunt patency without increasing the risk of hepatic encephalopathy and with a trend towards better survival.

Intraluminal brachytherapy of de novo TIPS: a prospective randomized double-blind study

OBJECTIVE

The aim of this prospective double-blind and randomized study was to assess whether intraluminal brachytherapy of de novo transjugular intrahepatic portosystemic shunts (TIPS) can prevent significant shunt stenosis.

SUBJECTS AND METHODS

Forty patients with portal hypertension due to liver cirrhosis were enrolled. In the irradiation group of 20 patients, the gamma radiation source, iridium-192, was introduced into the shunt within a special balloon catheter that allows the radionuclide to be centered within the shunt. A dose of 14 Gy in the shunt wall at a depth of 2 mm should be achieved. In the control group of 20 patients, a dummy source was used. Doppler sonography was performed immediately, 1 day, 1 week, 4 weeks, and 3 months after TIPS placement and then at an interval of 3 months during the first year. The primary end point of the study was the percentage of patients who developed significant shunt stenosis, defined as a reduction of maximum flow velocity below 50 cm/sec in the proximal part of the shunt 1 cm from the entry of the stent into the punctured portal vein branch. Fisher's exact test was used.

RESULTS

The TIPS procedure was technically successful in all patients. Seventeen patients in the irradiation group and 15 patients in the control group were followed up. Five patients (29.4%) in the irradiation group and 10 (66.7%) in the control group developed significant shunt stenosis during the first year after TIPS placement (p = 0.0392). The time until such stenosis occurred did not differ significantly between the two groups.

CONCLUSION

Our results suggest that brachytherapy can be useful in reducing the incidence of TIPS stenosis. A larger study with histopathologic analysis may be needed to confirm these findings.

Transjugular intrahepatic portosystemic shunt

The transjugular intrahepatic portosystemic shunt (TIPS) is an interventional treatment resulting in decompression of the portal system by creation of a side-to-side portosystemic anastomosis. Since its introduction 16 years ago, more than 1,000 publications have appeared demonstrating broad acceptance and increasing clinical use. This review summarizes our present knowledge about technical aspects and complications, follow-up of patients and indications. A technical success rate near 100% and a low occurrence of complications clearly depend on the skills of the operator. The follow-up of the TIPS patient has to assess shunt patency, liver function, hepatic encephalopathy and the possible development of hepatocellular carcinoma. Shunt patency can best be monitored by duplex sonography and can avoid routine radiological revision. Short-term patency may be improved by anticoagulation, while such a treatment does not influence long-term patency. Stent grafts covered with expanded polytetrafluoroethylene show promising long-term patency comparable with that of surgical shunts. With respect to the indications of TIPS, much is known about treatment of variceal bleeding and refractory ascites. The thirteen randomized studies that are available to date show that survival is comparable in patients receiving TIPS or endoscopic treatment for acute or recurrent variceal bleeding. Another group comprises patients with refractory ascites and related complications, such as hepatorenal syndrome and hepatic hydrothorax. It has been demonstrated that TIPS improves these complications. Five randomized studies comparing TIPS with paracentesis and one study comparing TIPS with the peritoneo-venous shunt showed good response of ascites but controversial results on survival. In addition, TIPS has been successfully applied to patients with Budd-Chiari syndrome, portal vein thrombosis, before liver transplantation, and for the treatment of ectopic variceal bleeding.

Early and long-term clinical and radiological follow-up results of expanded-polytetrafluoroethylene-covered stent-grafts for transjugular intrahepatic portosystemic shunt procedures

The purpose of this study was to assess the therapeutic efficacy and immediate and long-term safety of expanded-tetrafluoroethylene covered stent-grafts for transjugular intrahepatic portosystemic shunts in patients with portal hypertension-related complications. A cohort of 56 patients suffering from severe portal hypertension-related complications underwent implantation of an expanded-polytetrafluoroethylene-covered stent-graft. All patients suffered from severe liver cirrhosis graded Child-Pugh A (n=8; 16%), B (n=13; 21%) or C (n=35; 63%). In 44 patients, the stent-graft was placed during the initial TIPS procedure (de novo TIPS); in the other 12 patients, the stent-graft was placed to repermeabilize the previously placed bare stent (TIPS revision). Follow-up was performed with clinical assessment, duplex ultrasound and, if abnormal or inconclusive, with invasive venography and pressure measurements. Per- en immediate post-procedural complications occurred in four patients (4/56, 7%). None of them was lethal. During follow-up, stent occlusion appeared in one patient and stenosis in two; no recurrence of bleeding was noted in all patients treated for variceal bleeding (n=28), and 24 of the 28 patients (86%) suffering from refractory ascites and/or hepatic hydrothorax were free of regular paracenteses and/or drainage of pleural effusion after shunt creation. The 30-day and global mortality for the total study population (n=56) was, respectively, 7% (n=4) and 28.5% (n=16). In the patient subgroup with variceal bleeding (n=28), 30-day mortality was 3.5% (n=1) and global mortality 14.2% (n=4). In the ascites and/or hydrothorax subgroup (n=28), 8.1% (n=3) mortality at 30 days was found and global mortality was 32.4% (n=12). In 10 patients of the 56 studied patients (18%), isolated hepatic encephalopathy occurred, which was lethal in 4 (Child C) patients (7%). Three of these four patients died within the 1st month after TIPS placement. A very high primary patency rate of TIPS can be obtained long-term after implantation of an e-PTFE-covered stent-graft, leading to a definitive resolution of portal hypertension-related complications. The incidence of TIPS-induced hepatic encephalopathy is acceptable.