Introduction: To review our experience with repeat revascularization for moyamoya disease and investigate its effect on outcome.
Methods: Single institution, retrospective analysis of a prospective MMD database.
Results: From 1991-2014, 1244 revascularization bypass (1107 direct, 137 indirect) were performed in 765 patients, of whom 57 were repeat revascularizations.
Patients with previous indirect bypass: 38 (23F,15M) underwent 56 repeat revascularizations. 42% (16/38) were pediatric patients. Mean time to repeat surgery was 49 months (3-264). Indications for repeat surgery included TIAs (26 patients, 68%), new strokes (9), worsening developmental delay with seizure (3). Of the repeat surgeries, 59% (33/56) had direct bypasses (28 STA-MCA, 4 OA-MCA, 1 saphenous-MCA ) and 23 had indirect (4 EMS, 6 EDAS, 4 EDAMS, 8 omental-cerebral transpositions, 1 burrholes). Mean follow up was 4.8 years (0-16) and 81% (29/36) of the surviving patients are well with no TIAs/stroke.
Patients with previous direct bypass: 19 (16F,3M) required 20 repeat revascularizations. 26% (5/19) were pediatric patients. Mean time to repeat surgery was 47 months (0.2-200). Indications for repeat surgery include TIAs (13 patients, 68%), new strokes (4), 1 acute graft occlusion and 1 with persistent steal despite surgery. 55% (11/20) of repeat revascularizations were to augment blood supply in another vascular territory and this was achieved using another direct bypass technique (ie frontal STA branch or occipital artery). Other procedures included 3 EMS, 1 EDAS, 5 omental-cerebral transposition. Mean follow up was 4.7 years (0.5-21), 82% (14/17) of the surviving patients are well with no TIAs/stroke.
When the initial revascularization was performed at Stanford, the rate of repeat revascularization was 4% (5/137) and 1% (12/1107) for indirect and direct bypass respectively (p=0.0312).
Conclusions: When indicated, repeat revascularization is safe and effective in preventing future ischemic events. Indirect bypass has a higher rate of repeat revascularization. Over 50% of repeat revascularization were achieved with direct procedures.
Patient Care: Symptomatic moyamoya patients after initial revascularization procedures have high rate of symptomatic improvement after repeat revascularizations. In over half the cases, direct bypass could be achieved, which has been shown to have lower rate of repeat revascularization in our study, in conjunction with other benefits over indirect bypass according to the published literatures. However choice of procedure depends on operative findings and status of donor and recipient vessels.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) understand the indications for repeat revascularizations for moyamoya disease.
2) discuss the difference in treatment options for repeat revascularizations, the pros and cons of each technique.
3) determine the different repeat revascularization rates after initial direct or indirect bypass.