Comparative Assessment of Extracranial-to-Intracranial and Intracranial-to-Intracranial In Situ Bypass for Complex Intracranial Aneurysm Treatment Based on Rupture Status: A Case Series

Abstract

Comparative outcomes of extracranial-to-intracranial (EC-IC) and intracranial-to-intracranial (IC-IC) bypass for complex aneurysm treatment based on rupture status are not well described in the literature. In this study, we compare outcomes of EC-IC and IC-IC bypass for complex intracranial aneurysm treatment based on rupture status. A prospective neurosurgical patient database was retrospectively reviewed. Sixty-three consecutive patients with aneurysm managed with revascularization were identified between July 2014 and December2018. During the study period, 41 patients with aneurysm underwent EC-IC bypass (65%; 24 [58.5%] ruptured, 17 [41.5%] unruptured) and 22 patients with aneurysm underwent IC-IC bypass (34.9%; 13 [59.1%] ruptured, 9 [40.9%] unruptured). Graft spasm occurred in 4 patients (9.8%) in the EC-IC group (all ruptured aneurysms) and all anastomoses were patent on immediate postoperative imaging. Perioperative mortality occurred in 5 patients who underwent EC-IC bypass (12.2%; 3 ruptured, 2 unruptured) EC-IC and 2 patients who underwent IC-IC bypass (9.1%; both ruptured); (P= 0.709). Bypass-related complications occurred only in patients with ruptured aneurysm (2 [8.3%] in the EC-IC group and 0 [0%] in the IC-IC group; P= 0.285). For unruptured aneurysms, the overall complication rate was lower in IC-IC compared with the EC-IC group (P= 0.006). Modified Rankin Scale scores on discharge were significantly lower in IC-IC compared with EC-IC bypass for unruptured aneurysms (P= 0.008). There was a trend for shorter temporary occlusion and hospitalization times and overall better outcomes with IC-IC compared with EC-IC bypass. Although often considered riskier than EC-IC bypass, IC-IC in situ bypass showd a favorable technical and safety profile for the treatment of complex, unruptured aneurysms.