The interpositional bypass with a parietal branch of superficial temporal artery graft for symptomatic atherosclerotic anterior cerebral artery stenosis or occlusion.

Background: For nonmoyamoya patients with anterior cerebral artery (ACA) stenosis or occlusion, whether direct revascularization of the ACA territory can prevent stroke is still unclear. The objective of this study was to investigate the efficacy and safety of a parietal branch of superficial temporal artery-interposed superficial temporal artery-to-ACA bypass (PISAB) for preventing stroke in patients with symptomatic atherosclerotic ACA stenosis or occlusion (SAASO). Methods: We retrospectively analyzed the data from patients with SAASO who had undergone PISAB in our center between April 2016 and November 2021. The rates of patency, satisfaction (revascularization grades A and B) of bypass, perioperative complications, recurrence of ischemic stroke, changes in bypass flow, and improvements in cerebral blood perfusion were analyzed. Results: A total of 19 SAASO patients were involved in this study. Sixteen out of 19 (84.2%) patients were free from any cerebral ischemic events after surgery. Only 3 patients (15.8%) had recurrent stroke postoperatively. Two (10.5%) surgery-related complications occurred, including hyperperfusion syndrome and minor stroke. No skin ischemic complications occurred. The average follow-up period was 50.6 ± 18.3 months. The flow rate of the bypass was significantly increased half a year after surgery (56.2 ± 8.0 mL/min vs. 44.3 ± 5.3 mL/min, p < 0.001). The ratio of ipsilateral/contralateral mean transit time in the superior frontal gyrus was decreased significantly after bypass (1.08 ± 0.07 vs. 1.23 ± 0.05, p < 0.001) and continued to decrease 6 months after surgery (1.05 ± 0.04 vs. 1.08 ± 0.07, p = 0.002). The patency rate of PISAB was 94.7% (18/19) 2 years after surgery. The satisfaction rate of bypass was 89.5% (17/19). Conclusion: The results of this study indicate that PISAB, as a safe superficial bypass, can effectively reduce the risk of stroke in SAASO patients. More precise conclusions will require randomized control studies.

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.

The History and Evolution of Internal Maxillary Artery Bypass.

Internal maxillary artery (IMA) bypass has gained momentum in the last 5 years for the treatment of complex cerebrovascular disorders and skull base tumors. However, some issues regarding this treatment modality have been proposed. As one of the most experienced neurosurgical teams to perform internal maxillary artery bypass in the world (>100 clinical cases), we reviewed the literature in aspects of basic anatomy of maxillary artery with its variations to the lateral pterygoid muscle, initial anastomosis modalities, and subsequent exposure techniques in cadaver studies, preoperative arterial evaluation methods, optimal interposed graft selections, and surgical outcome in the management of complex aneurysms, skull base tumors, and steno-occlusive disorders.