Technical Considerations for Optimizing Flow in Superficial Temporal Artery to Middle Cerebral Artery Bypass: Case Series.

BACKGROUND AND

OBJECTIVES

Cerebral bypass can provide flow augmentation for select patients with moyamoya disease (MMD) and steno-occlusive cerebrovascular disease (SOCD). Earlier work has suggested that sacrificing the nondonor branch of the superficial temporal artery (STA) can optimize direct flow, which we assessed in real time.

METHODS

This was a single-institution observational study of consecutive patients undergoing direct STA-middle cerebral artery (MCA) bypass with indirect encephalo-duro-myo-synangiosis for MMD and SOCD over 1 year. Excluding patients with significant STA-intracranial collateralization, the intraoperative effect of nondonor STA branch temporary occlusion on direct STA-MCA bypass flow was assessed using a Charbel flow probe. Patient characteristics and perioperative and postoperative data were reviewed.

RESULTS

Eleven patients (5 MMD, 6 SOCD; mean age 53.5 ± 15.3 years) underwent combined revascularization (4 left, 7 right). The mean donor STA branch flow increased from 4.91 ± 2.79 (baseline) to 16.63 ± 11.92 mL/min after anastomosis (95% CI 1.25-17.50; P = .015), and to 20.94 ± 10.63 mL/min after nondonor STA branch test occlusion (95% CI 1.71-6.90; P = .002). The parietal STA branch was used as the donor in 8 cases (72%). In 9 patients, the nondonor STA branch was sacrificed. Perioperatively, 1 patient experienced transient dysarthria/paresthesias (9.1%); there were no strokes or other major complications. The median hospital stay was 5.0 (IQR 4.0, 7.0) days, with 81% of patients discharged home. Over a mean follow-up of 6.2 ± 3.0 months, no patients had significant wound-healing issues, and the median modified Rankin Scale score improved from 2 (IQR 1.0, 2.5) preoperatively to 0 (IQR 0.0, 0.0) (95% CI 0.11-1.69; P < .015). Six-month angiography (available in 9 patients) demonstrated 100% direct bypass patency and a median direct bypass flow grade of 2.0 (IQR 2.0, 3.0).

CONCLUSION

In patients without STA-intracranial anastomoses, STA-MCA direct bypass flow may be optimized safely by nondonor STA branch sacrifice.