A Novel Cautery Instrument for On-Site Fenestration of Aortic Stent-Grafts: A Feasibility Study of 18 Patients

PURPOSE: To report the bench-top evaluation and initial clinical use of an instrument for on-site fenestration of aortic stent-grafts. METHODS: A stainless steel thermal cautery instrument was designed to create circular stent-graft fenestrations from 3 to 10 mm in diameter. Three operators independently bench-tested the instrument on thoracic stent-graft samples to evaluate size, shape, location, and quality of fenestrations created. For clinical use, on-site fenestration was performed 2 days before the endovascular procedure in a sterile room without access to supplemental oxygen. A fenestrator 1 or 2 mm smaller in diameter than the target vessel was used; the edges of the fenestrations were strengthened using flexible radiopaque nitinol wire. The aortic stent-graft was then re-sheathed and sterilized for added safety. Eighteen patients (17 men; mean age 51 years, range 18-80) with a variety of thoracic and juxtarenal pathologies were treated using Zenith TX2, Valiant Captivia, Zenith AAA, and Endurant stent-grafts modified in this manner. RESULTS: After successful bench testing, the instrument was used to create 34 fenestrations in aortic stent-grafts deployed in the 18 patients. Size and location of fenestrations obtained were as desired. Subsequent catheterization of the fenestration/target vessel and covered stent deployment were successfully achieved in 31 (91%) fenestrations; 2 fenestrations had type III endoleaks and 1 fenestration was unused. There was no perioperative mortality, stroke, embolization, vessel dissection, renal failure, or graft infection. Follow-up to 1 year in the majority of patients has revealed no new fenestration-related problems. CONCLUSION: This simple-to-use instrument makes on-site creation of aortic stent-graft fenestrations easy, accurate, and precise. The instrument is inexpensive, robust, and easily sterilized.