A flow self-regulating STA-MCA bypass based on side to side fashion anastomosis for adult patients with moyamoya disease

OBJECTIVESide to side (S-S) fashion superficial temporal artery-middle cerebral artery (STA-MCA) bypass was reported for treating a special moyamoya disease (MMD) patient with collaterals arising from the donor STA. However, the S-S technique is not routinely performed to date and its benefits are still unknown for adult MMD. The purpose of this study is to investigate the possibility of routine use of the S-S technique for adult MMD. METHODSThe authors retrospectively analyzed the clinical data from 50 adult patients (65 hemispheres, including 30 in end to side [E-S] group and 35 in S-S group) with MMD underwent STA-MCA bypass. The patients demographics, clinical courses, technical details, intraoperative blood flow, post- and preoperative relative cerebral blood flow (rCBF) values, modified Rankin Scale (mRS) scores and short-term revascularization results were compared between the two groups. RESULTSThere was no significant difference observed in terms of baseline characteristics, bypass patency rates, post-/ preoperative rCBF values, incidence of cerebral hyperperfusion syndrome (CHS), improvement of mRS scores and short-term revascularization results between the two groups (P all > 0.05). Intraoperative blood flow analysis showed the increase of STA flow in the E-S group was significantly higher than that of proximal STA flow in the S-S group (P = 0.008 <0.05). Although the increases of proximal and distal recipient flow in the E-S group seemed higher than those in the S-S group, the results were not statistically significant (P = 0.086 in proximal and P = 0.076 in distal). The CHS symptoms were milder and their duration time was much shorter in the S-S group. The follow-up angiographic data of the representative case amazingly demonstrated that all the frontal and parietal STA branch and occipital artery participated in the postoperative collateralization. CONCLUSIONSS-S anastomosis can achieve comparable clinical effects to standard E-S construction. S-S anastomosis used in adult MMD demonstrated mild CHS symptoms with short duration time and had the potential to arouse all scalp arteries as donor sources for revascularization through the intact distal STA by a flow self-regulating fashion.