The Diamond™ endobiliary stent (Microvasive, Natick, MA) is constructed of nitinol wire strands laser welded together in a diamond configuration conveying high radial-force, kink-resistant properties. We evaluated the stent in a porcine model. METHODS: A total of 12 stents were placed over two sessions. The following parameters were assessed: ease of delivery & deployment (4 pt scale); expansion (measured by retrieval balloon); fluoroscopic appearance; accuracy of deployment (within 5 mm of intended margins); repositioning; biotolerance; and complications. RESULTS: The stent is compressed onto a flexible delivery catheter by a transparent plastic oversheath with a 3 mm outer diameter. Post-deployment diameter is 10 mm, lengths 4 & 8 cm. The delivery system passed easily through the Olympus TJF-100 duodenoscope, over an .035″ guidewire, and through the un-adultered sphincter choledocus, into the CBD. The stent lattice-work and proximal and distal radiographic markings were well seen fluoroscopically. Stent deployment occurred with a 1:1 withdrawal of the oversheath. Once partial deployment was initiated, the stent could be repositioned more distally in the CBD but could not be advanced more proximally nor recaptured. The stent reliably deployed to its full diameter immediately on release. Accuracy of deployment was 92%. Deployed stents that traversed the ampulla could be immediately removed with a snare or biopsy forceps. No procedure related complications were encountered. At 10 week follow-up no survival subjects had clinical evidence of biliary obstruction or stent related complications. Necropsy and explantation in two subjects at week 10 demonstrated no stent migration and minimal to no appreciable epithelial hyperplasia or biliary sludge accumulation grossly and microscopically. CONCLUSIONS: 1) The porcine model is an effective tool for evaluating new endotherapies. 2) The Diamond endobiliary stent demonstrated ease of delivery without sphincterotomy; accurate deployment with immediate and full expansion; and excellent biotolerance. 3) This endobiliary stent has potential advantages over currently available biliary stents warranting further investigation.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging