481 Troubleshooting the Bypass: Intraoperative Management of Initially Failed Anastomosis in Cerebral Extracranial – Intracranial Direct Revascularization Surgery

Abstract

INTRODUCTION: Direct cerebral revascularization is considered one the most technically challenging operations in neurosurgery. Technical errors are often not identified during the completion of the anastomosis. Initial assessment and management at this moment can determine the success of the entire case, making re-circulation one of the most stressful moments in the procedure. METHODS: A retrospective analysis of direct bypass cases based on operative reports and available videos, were studied in detai. A case was defined as an “initially failed bypass”, irrespective of its final result, if after removal of the temporary clips, the bypass was not patent, or significant leak was encountered. RESULTS: 138 cases were included (109 being STA-MCA) done for flow replacement (n = 49), or for flow augmentation (n = 89). 45 initially failed anastomosis, out of which 37 were the result of a technical error encounterd. Causes were clot(n = 10), vessel kinking(n = 5), spasm(n = 6), inappropriate donor(n = 3) or recipient(n = 2), competitive flow(n = 6) or a leak(n = 5). 31/37 cases were troubleshooted successfully resulting in a working bypass. Rescue maneuvers included: Partial re-opening of the suture line and irrigation for clot, graft repositioning for kinking, papaverine-vessel massage for spasm, and partial vessel cut at the donor site for anastomosis inspection. In “local” lack of demand, a new anastomosis was done by the same donor. 30-days follow-up showed similar rates of patency between successfully troubleshooted patients and the rest of the patients (82% vs 85%, p = 0.35). CONCLUSIONS: A comprehensive approach detailing technical “corrections”, describing maneuvers and the sequence of actions done in order to “revive” the bypass, as well as their prevalence, was not previously well described. In this study we present 3 of initial failure types: a leak, acute occlusion or delayed occlusion, presenting an algorithm for intra-operative management in these cases.