Intracranial-Intracranial Bypass with a Graft Vessel: A Comprehensive Review of Technical Characteristics and Surgical Experience.

Objective: Intracranial-intracranial (IC-IC) bypass with a graft vessel (IBGV) is a straightforward arterial reconstruction technique used for the treatment of complex aneurysms and skull base tumors. We have described the technical characteristics and summarized the clinical results of IBGV in complex cerebrovascular disorders.

Methods: We performed a search of the PubMed and Google Scholar online databases. The terms "intracranial-intracranial bypass," "jump graft bypass," "interposition graft bypass," "radial artery graft bypass," "saphenous vein graft bypass," and "superficial temporal artery graft bypass" were searched. Studies involving IBGV combined with other bypass methods were excluded. Illustrations of the technique have been provided to enhance comprehension.

Results: We identified 59 cases involving 6 types of graft vessels were identified from 1978 to July 2018. The IBGV technique was divided into the following 4 subtypes: type IA, in situ interposition graft bypass; type IB, Y-shaped double-barrel interposition graft bypass; type IIA, long jump graft bypass; and type IIB, Y-shaped double-barrel jump graft bypass. Grafts from the radial (44.1%; 26 of 59) and superficial temporal (39.3%; 22 of 59) arteries were used most frequently, and the middle cerebral artery territory was the most commonly involved region for IBGV. Of the cases with the specified postoperative characteristics, the graft patency and overall uneventful rates were 96.3% (52 of 54) and 82.2% (37 of 45), respectively. A higher patency rate (100% vs. 90.5%) and a lower complication rate (<20% vs. 60%) were observed with the type II group with an arterial graft.

Conclusions: The IBGV method is a technically feasible option for vascular disease or complex cerebral tumors and should be considered by neurosurgeons. Long jump bypass with arterial grafts should be preferred when IC-IC bypass has been considered owing to the high rates of graft patency and favorable clinical outcomes.