A new partially covered nitinol stent for palliative treatment of malignant bile duct obstruction: a multicenter single-arm prospective study.

BACKGROUND AND STUDY AIMS: Covered self-expanding metal stents (SEMSs) have proven effective for managing malignant bile duct strictures and may reduce risk of tumor ingrowth. A new nitinol partially covered biliary SEMS was prospectively evaluated. PATIENTS AND METHODS: 70 patients with inoperable extrahepatic biliary obstructions were enrolled in a prospective multicenter trial, and followed up to 6 months or death, whichever came first. Primary endpoint was adequate palliation defined as absence of recurrent biliary obstruction from partly covered SEMS placement to end of follow-up. RESULTS: Mean age of the patients was 69 years and 52 % were men. Pancreatic carcinoma was present in 68 %. One stent was placed in 67 patients, two patients received two, and in one patient a guide wire could not traverse the stricture. In 55 % of patients the SEMS was inserted de novo and in 45 % for exchange with a plastic stent. Technical success was 97 %. At 6 months, 62 % of patients were free of obstructive symptoms; compared with baseline the mean number of symptoms per patient was significantly reduced (3.1 at baseline, 0.6 at 6 months; P < 0.0001) and total bilirubin levels dropped by 73 %. There were four cases of recurrent biliary obstruction, due to stent migration (2), tumor overgrowth (1), and sludge formation (1). Device-related complications included cholecystitis (3), right upper quadrant pain (1), and moderate pancreatitis (1). No tumor ingrowth was reported. CONCLUSIONS: This new partially covered nitinol SEMS is easily inserted, and safe and effective in the palliation of biliary obstruction secondary to malignant bile duct strictures.

Diversity of the vif gene of human immunodeficiency virus type 1 in Uganda.

Little sequence information is available for human immunodeficiency virus type 1 (HIV-1) vif genes of African origin. Here we describe 37 new complete vif genes of 18 AIDS patients from Uganda and show that vif has a high in vivo genetic variability. vif proviral DNA sequences of peripheral blood cells were determined by direct sequencing of PCR products. Only 52% of the deduced Vif amino acids were absolutely conserved; when Vif sequences previously analysed were considered, only 32% of the Vif consensus sequence comprised conserved and as such possibly functionally important motifs. The high inter-individual vif variability was in contrast to a very low intra-individual variability. One patient carried a vif gene with a stable C-terminal deletion, but N-terminal truncations were not found in patients' predominant vif sequences. The vif genes analysed comprised subtypes A, D and an A/D mosaic. Phylogenetic analyses additionally showed that HIV- 1 in Uganda has spread across the boundaries of ethnic groups.