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The 2009 update of the American Association for the Study of Liver Diseases (AASLD) Practice Guideline "The Role of Transjugular Intrahepatic Portosystemic Shunt (TIPS) in the Management of Portal Hypertension" is now posted online at www.aasld.org. This is the first update of the original guideline published in 2005. 1 The key changes in the 2009 guidelines are new recommendations on the use of covered versus bare stents in the creation of the TIPS. Use of expanded polytetrafluoroethylene (ePTFE)-covered stents is now preferred. The lower risk of shunt dysfunction and perhaps improved outcomes using covered as opposed to bare stents are the basis for this recommendation. 2,3 Creation of a TIPS increases the risk of hepatic encephalopathy but the prophylactic use of nonabsorbable disaccharides or antibiotics does not appear to reduce this risk and is not recommended. 4 The value of TIPS versus a surgical shunt in the prevention of variceal rebleeding in patients who have failed medical therapy has been clarified by the publication of a controlled trial comparing TIPS to distal splenorenal shunt (DSRS). 5 Both were effective in preventing rebleeding (rebleeding incidence in 5.5% of DSRS versus 10.5% of TIPS; not significant) with no difference in encephalopathy or survival. The patients in whom TIPS was performed required significantly more interventions to maintain patency because of the use of bare stents. A cost analysis showed TIPS to be slightly more cost effective than DSRS at year 5, 6 and these two approaches are now considered to be of equal efficacy in the prevention of variceal rebleeding.The other significant change to the guidelines is how TIPS should be used in the management of patients with Budd-Chiari syndrome. A large (221 patients) retrospective study was published in which patients who failed to improve with use of anticoagulation had a TIPS created (133 patients). One-year and 10-year transplant-free survival was 88% and 69%, respectively, which is better than predicted. 7 TIPS patency was best in those who received a covered stent. The recommendation now is for creation of a TIPS in those who fail to improve with anticoagulation.

Ornithine transcarbamylase deficiency (OTCD) is an inborn error of urea synthesis that has been considered as a model for liver-directed gene therapy. Current treatment has failed to avert a high mortality or morbidity from hyperammonemic coma. Restoration of enzyme activity in the liver should suffice to normalize metabolism. An E1- and E4-deleted vector based on adenovirus type 5 and containing human OTC cDNA was infused into the right hepatic artery in adults with partial OTCD. Six cohorts of three or four subjects received 1/2 log-increasing doses of vector from 2 x 10(9) to 6 x 10(11) particles/kg. This paper describes the experience in all but the last subject, who experienced lethal complications. Adverse effects included a flu-like episode and a transient rise in temperature, hepatic transaminases, thrombocytopenia, and hypophosphatemia. Humoral responses to the vector were seen in all research subjects and a proliferative cellular response to the vector developed in apparently naive subjects. In situ hybridization studies showed transgene expression in hepatocytes of 7 of 17 subjects. Three of 11 subjects with symptoms related to OTCD showed modest increases in urea cycle metabolic activity that were not statistically significant. The low levels of gene transfer detected in this trial suggest that at the doses tested, significant metabolic correction did not occur.

with TEVAR was impressive. With longer follow-up, this may translate into improved survival with fewer long-term complications. Stent Graft versus Balloon Angioplasty for Failing Dialysis-Access GraftsHaskal ZJ, Trerotola S, Dolmatch B, et al. N Engl J Med 2010;362:494-503. Conclusion: Revision of a venous anastomotic stenosis of a prosthetic dialysis access graft with a stent graft provides longer-term patency and freedom from repeat intervention than revision with standard balloon angioplasty.Summary: Secondary patency of hemodialysis grafts is at best 50% at 3 years. Many interventions are typically required to maintain dialysis-access graft patency. The authors sought to test the hypothesis that revision of venous anastomotic stenosis with stent grafts constructed with the same material as the dialysis-access graft itself would improve long-term patency compared with that provided by revision with balloon angioplasty alone. Theoretically, stent graft revision would prevent elastic recoil associated with balloon angioplasty alone and prevent intimal hyperplasia in-growth at the venous anastomosis, resulting in improved patency of the revised grafts.This was a prospective multicenter trial. There were 190 patients undergoing hemodialysis with dialysis-access grafts and a venous anastomosis stenosis that were randomly assigned to receive balloon angioplasty alone or balloon angioplasty plus placement of a stent graft at the site of the venous anastomotic lesion. Patency of the treatment area and patency of the entire vascular access graft were the primary end points.At 6 months, patency of the treatment area was greater in the stent graft group than in the balloon angioplasty group (51% vs 23%, P Ͻ .001). Six-month patency of the dialysis access circuit was improved in the stent graft group vs the balloon angioplasty group (38% vs. 20%, P ϭ .008). Freedom from subsequent intervention at 6 months was also greater in the stent graft group than in the balloon angioplasty group (32% vs 16%, P ϭ .03). Restenosis was greater in the balloon angioplasty group than in the stent graft group (78% vs 28%, P Ͻ .001). Other adverse events at 6 months were equivalent in the two treatment groups.Comment: There is still a need for dialysis-access grafts. Results of this study suggest stent grafts provide better patency in treating venous anastomotic strictures of dialysis-access grafts than that provided by balloon angioplasty alone. Although the results are statistically significant, there are details to be considered before declaring the results clinically significant. Grafts in this study were treated before actual thrombosis. Many access grafts do not come to revision until they have thrombosed, and it is controversial whether surveillance and treatment of patent, but not thrombosed dialysis grafts, actually results in overall prolongation of usable access. In addition, 6 months after revision with a stent graft, there is primary patency in only half the patients. Stent grafts are more expensive than balloon angioplasty a...

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