Postoperative neovascularization, cerebral hemodynamics, and clinical prognosis between combined and indirect bypass revascularization procedures in hemorrhagic moyamoya disease

Abstract

Objective: We evaluated what few studies emphasized the postoperative collateral formation and cerebral hemodynamics of hemorrhagic moyamoya disease (MMD).

Methods: Hemorrhagic MMD patients treated surgically were retrospectively collected and dichotomized into combined bypass (CB) and indirect bypass (IB) groups. CB used superficial temporal artery-to-middle cerebral artery anastomosis combined with encephaloduroarteriomyosynangiosis (STA-MCA+EDAMS), and IB used encephaloduroarteriomyosynangiosis (EDAMS) for revascularization. Postoperative complications and clinical prognosis, as well as pre- and post-operative Modified Rankin Scale (mRS), collateral circulation status, and cerebral hemodynamics were observed and compared between the CB and IB groups.

Results: A total of 37 patients with hemorrhagic MMD were identified. Of the 68 cerebral hemispheres, 47(69.1%) were combined revascularization, and the rest were indirect. During an average follow-up of 16.5 ± 8.7 months, the recurrent stroke events were significantly lower, as well as having a postoperative mRS scores≤ 2. A satisfactory postoperative collateral formation, and an improved dilation or extension of the anterior choroidal/posterior communication artery (AchA/PcoA) were significantly higher in the CB group than in the IB group (all P < .05). Compared with preoperative cerebral hemodynamics, relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), mean transit time (MTT), and relative time to peak (rTTP) in the CB group; rCBF, rCBV, and MTT in the IB group were significantly improved (all P < .001). The CB group's postoperative rCBF was significantly improved compared with the IB group (P < .001).

Conclusions: STA-MCA bypass combined with EDAMS can obtain better postoperative collateral formation, cerebral hemodynamics, and clinical prognosis than EDAMS alone.

Keywords: Combined bypass; Hemodynamics; Hemorrhagic moyamoya disease; Indirect bypass; Postoperative collateral formation.