Superficial temporal artery to middle cerebral artery bypass for moyamoya disease
The superficial temporal artery is a useful donor artery for direct bypass surgery for moyamoya disease and can provide sufficient blood supply to the ischemic cerebral territory 1).
Combined with a temporal muscle patch can deliver a higher total clinical curative rate for patients with moyamoya disease and can alleviate their coma 2).
Clinical success
Collateral artery formation from the extracranial carotid artery to ischemic brain tissue determines the clinical success of superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery in adult patients with moyamoya disease, but postoperative collateral formation (PCF) after STA-MCA bypass surgery is unpredictable. Accurate preoperative prediction of acceptable PCF could improve patient selection. Sun et al. aim to develop a prediction nomogram model for PCF in this patient population.
Adult patients with moyamoya disease undergoing the STA-MCA bypass surgery between January 2013 and December 2020 at a single institution were retrospectively or prospectively enrolled in this observational study. Data including potential clinical and radiological predictors were obtained from hospital records. A nomogram was generated based on a multivariate logistic regression analysis, to identify potential predictors associated with good PCF. The performance of the nomogram was evaluated for discrimination, calibration, and clinical utility.
Data from 243 patients with moyamoya disease who underwent the STA-MCA bypass surgery were analyzed to build the nomogram. After 1-year follow-up, 162 (66.7%) hemispheres had good PCF and 81 (33.3%) had poor PCF. Good PCF is associated with 3 preoperative factors: age at operation, the diameter of the donor branch of STA, and the preinfarction period stage. Incorporating these 3 factors, the model achieved a concordance index of 0.88 (95% CI, 0.84-0.92) and had a well-fitted calibration curve and good clinical application value. A cutoff value of 100 was determined to predict good PCF via this nomogram.
The nomogram exhibits high accuracy in predicting good PCF after the STA-MCA bypass surgery in adult patients with moyamoya disease and may allow surgeons to better evaluate preoperatively candidacy for successful bypass surgery 3).
Complications
Case series
Data for consecutive patients who underwent STA-MCA MVB from 2000-2019 due to moyamoya/moyamoya-like disease, complex intracranial aneurysms, or intractable brain ischemia due to internal carotid artery or middle cerebral artery occlusive disease with repeated ischemic events were retrospectively analyzed under a waiver of informed consent. Key surgical steps and the important role of neuroendovascular interventions are presented. Surgical results and late outcomes were analyzed.
The study was comprised of 32 patients (17 women [53%], 15 men [47%]), mean age 42.94 years (range 16-66). Patients underwent 37 STA-MCA MVB procedures during the study period; 22 with moyamoya/moyamoya-like disease (69%) underwent 27 surgeries (five bilateral); 7 with complex aneurysms (22%) and 3 with vascular occlusive disease (9%) underwent unilateral bypass. Five of seven aneurysms were treated with coiling or flow-diverter stent implant prior to bypass surgery; two were clipped during the bypass procedure. There were no surgical complications, no perioperative mortality, and no death from complications related to neurovascular disease at late follow-up. Transient neurological deficits following 8/37 (21%) resolved with no permanent neurologic sequelae. Transient ischemic attacks occurred only in the immediate postoperative period in four patients (11%).
In specific cases, STA-MCA MVB is a feasible and clinically effective procedure. It is important to preserve this technique in surgical armamentarium 4).
From October 2005 to November 2009, Xu et al. from the Department of Neurosurgery, Fudan University, Shanghai, China performed a combined revascularization procedure in 111 patients with different types and stages of moyamoya disease. The superficial temporal artery, middle meningeal artery and the deep temporal artery were evaluated for individualized surgical planning in these cases. The integrity of the deep temporal artery and the middle meningeal artery network, and the pre-existing spontaneous anastomoses of the distal branches of the external carotid artery with the cortical arteries were well preserved. The mean follow-up time was 72.5 months, all clinical and radiological data were retrospectively reviewed.
A total of 198 stomas were performed in 122 hemispheres, all remaining patent until the last follow-up. The encephalo-duro-myo-synangiosis resulted in extensive anastomoses of the deep temporal artery (100%), the middle meningeal artery (90.9%), and the sphenopalatine artery (39.8%) with the cortical arteries, respectively. The superficial temporal artery, deep temporal artery, and the middle meningeal artery were significantly thickened in 88 patients as determined by digital subtraction angiography at follow-up. The relative cerebral blood flow increased significantly within one week after the operation. At 6 months post the operation, the relative cerebral blood flow was further increased by 15.5% from the gradual formation of anastomoses as a result of indirect revascularization. Transient ischemic attacks were effectively reduced or totally arrested. The neurological deficits significantly improved in 37 patients, with the National Institutes of Health Stroke Scale scores lowered by 2-8. There was no rehemorrhage in hemorrhagic moyamoya disease patients.
This study showed that the superficial temporal artery-middle cerebral artery bypass combined with encephalo-duro-myo-synangiosis can achieve good therapeutic effect in the moyamoya disease treatment 5).