Implementation and Rationale for a Unified Clinical and Imaging Protocol for Evaluation and Treatment of Moyamoya Angiopathy: A Single Institutional Experience

Salvage Maneuvers for Occluded Bypass in Cerebral Revascularization Procedures

OBJECT

Cerebral revascularization is an effective measure for dealing with complicated intracranial aneurysms and ischemic cerebro-vascular disease. Intra-operative thrombosis causing bypass occlusion is a severe issue that cause devastating consequences for complication in revascularization. We report our experiences regarding salvage maneuvers for intraoperative thrombosis in cerebral revascularization procedures and discuss the characteristics and culprits.

METHODS

We investigated 720 consecutive patients who underwent cerebral revascularization at the First Affiliated Hospital of Soochow University from January 2013 to October 2021, including 688 patients who underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and 32 patients who underwent extracranial artery-radial artery (ECA-RA)-MCA bypass. Forty-one patients experienced intracranial aneurysms, and the remaining 679 patients was involved in moyamoya disease (MMD), skull base tumors, intracranial occlusive vascular diseases, or other cerebrovascular diseases. All clinical characteristics, clinical imaging examinations and neurological outcomes were studied pre- and postoperatively. The patency of bypasses was confirmed by intraoperative doppler ultrasonography and indocyanine green (ICG) videoangiography.

RESULTS

Seven intraoperative thromboses, which were confirmed by intraoperative doppler ultrasonography and ICG videoangiography, including STA-MCA bypass (n=5) and ECA-RA-MCA bypass (n=2), were observed in 720 patients who underwent cerebral revascularization. The anastomotic stoma remained patent in 6 of 7 patients with intraoperative thrombosis after treatment. One case in STA-MCA bypass failed to be salvaged. Of the four intraoperative thrombosis in STA-MCA bypass for MMD being successfully saved, two were salvaged by applying gelfoam around the site of the anastomosis to relieve the downward compression effect of the donor vessel(STA) on the recipient vessel(M4 segment of MCA).One case in ECA-RA-MCA bypass were salvaged by thrombectomy through donor arteriotomy (radial artery) and reanastomosis. The other case was salvaged by complete reanastomosis. All seven patients who experienced intraoperative thrombosis achieved favorable outcomes at discharge and the 6-month follow-up.

CONCLUSION

Various factors are responsible for intraoperative thrombosis in cerebral revascularization. Relieving the downward compression effect of the donor vessel STA on the recipient vessel M4 segment of MCA by applying gelfoam around the site of the anastomosis stoma, can be recommend to salvage the intraoperative thrombosis in cerebral revascularization.

European Stroke Organisation (ESO) Guidelines on Moyamoya angiopathy: Endorsed by Vascular European Reference Network (VASCERN)

The European Stroke Organisation (ESO) guidelines on Moyamoya Angiopathy (MMA), developed according to ESO standard operating procedure and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, were compiled to assist clinicians in managing patients with MMA in their decision making. A working group involving neurologists, neurosurgeons, a geneticist and methodologists identified nine relevant clinical questions, performed systematic literature reviews and, whenever possible, meta-analyses. Quality assessment of the available evidence was made with specific recommendations. In the absence of sufficient evidence to provide recommendations, Expert Consensus Statements were formulated. Based on low quality evidence from one RCT, we recommend direct bypass surgery in adult patients with haemorrhagic presentation. For ischaemic adult patients and children, we suggest revascularization surgery using direct or combined technique rather than indirect, in the presence of haemodynamic impairment and with an interval of 6–12 weeks between the last cerebrovascular event and surgery. In the absence of robust trial, an Expert Consensus was reached recommending long-term antiplatelet therapy in non-haemorrhagic MMA, as it may reduce risk of embolic stroke. We also agreed on the utility of performing pre- and post- operative haemodynamic and posterior cerebral artery assessment. There were insufficient data to recommend systematic variant screening of RNF213 p.R4810K. Additionally, we suggest that long-term MMA neuroimaging follow up may guide therapeutic decision making by assessing the disease progression. We believe that this guideline, which is the first comprehensive European guideline on MMA management using GRADE methods will assist clinicians to choose the most effective management strategy for MMA.

Brain perfusion and hemodynamic changes in moyamoya desease

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