Wound healing complications after revascularization for moyamoya vasculopathy with reference to different skin incisions

OBJECTIVEMoyamoya vasculopathy (MMV) is a steno-occlusive cerebrovascular disease that can be treated by a surgical revascularization. All the revascularization techniques influence the blood supply of the scalp, with a risk for wound healing disorders. The authors' aim was to analyze the wound healing process in the patients who underwent a direct or combined bypass surgery with a focus on different skin incisions.METHODSThe authors retrospectively identified all the patients with MMV who were treated surgically in their institution. Subsequently, they analyzed demographic data, clinical symptoms, surgical treatment, and detailed history of complications. Based on the evolution of their surgical techniques and the revascularization strategy to be used, the authors applied the following skin incisions: linear incision, curved incision, incomplete Y incision, and complete Y incision. Group comparisons regarding wound healing disorders were performed with significance testing using Fisher's exact test.RESULTSThe authors identified 172 patients with MMV (61.6% moyamoya disease, 7% unilateral moyamoya disease, 29.7% moyamoya syndrome, and 1.7% unilateral moyamoya syndrome), of whom 124 underwent bilateral operations. One-quarter of the patients were juveniles. A total of 236 hemispheres were included in the analysis, of which 27.9% were treated by a combined procedure with encephalomyosynangiosis. Overall, 5.1% major and 1.7% minor wound complications occurred. The overall wound complication rate was lower in direct revascularization compared to combined revascularization (3% vs 15.2%). The lowest incidence of wound healing disorders was found in the linear incision group for the parietal superficial temporal artery branch (1.6%), followed by the incomplete Y incision group for the frontal branch of the superficial temporal artery (3.8%) in the direct bypass group. In the combined revascularization cohort, major or minor wound disorders appeared in 14.3% and 4.8%, respectively, in the complete Y incision group and in 4.2% (for both major and minor) in the curved incision group. The complete Y incision caused significantly more wound healing disorders compared to the remaining incision types (17.1% vs 3.1%, p = 0.007).CONCLUSIONSWound healing disorders are one of the major complications of revascularization surgery. Their incidence depends on the revascularization strategy and skin incision applied, with a complete Y incision giving the worst results.

Experimental animal models for moyamoya disease and treatment: a pathogenesis-oriented scoping review

OBJECTIVE

Moyamoya disease (MMD) is an intracranial steno-occlusive pathology characterized by progressive narrowing of proximal large vessels, including the terminal internal carotid arteries (ICAs), middle cerebral arteries, or anterior cerebral arteries. Named for the "puff of smoke" appearance of the anomalous vascularization visualized on cerebral angiography, MMD lacks a well-defined etiology, although significant insights have been made, including the identification of a susceptibility gene, RNF213, in humans with the disease. A limitation to advancing the understanding and treatment of MMD has been the lack of experimental animal models that authentically reflect the clinical pathogenesis. In an effort to analyze characteristics of currently available models and identify strategies for future model generation, the authors performed a scoping review of experimental animal models that have been used to study MMD.

METHODS

A systematic search of PubMed, Web of Science, and Scopus was performed to identify articles describing animal models used to study MMD. Additional articles were identified via citation searching. Study selection and data extraction were performed by two independent reviewers based on defined inclusion and exclusion criteria.

RESULTS

A total of 44 articles were included for full-text review. The methods used to generate these animal models were broadly classified as surgical (n = 25, 56.8%), immunological (n = 7, 15.9%), genetic (n = 6, 13.6%), or a combination (n = 6, 13.6%). Surgical models typically involved permanent ligation of one or both of the common carotid arteries or ICAs to produce chronic cerebral hypoperfusion. Genetic models utilized known MMD or cerebrovascular disease-related genes, such as RNF213 or ACTA2, to induce heritable cerebral vasculopathy. Finally, immunological models attempted to induce vasculitis-type pathology by recapitulating the inflammatory milieu thought to underlie MMD.

CONCLUSIONS

Models generated for MMD have involved three general approaches: surgical, immunological, and genetic. Although each reflects a key aspect of MMD pathogenesis, the failure of any individual model to recapitulate the development, progression, and consequences of the disease underscores the importance of future work in developing a multietiology model.

Effect of thin-split encephalomyosynangiosis on transient neurological events in revascularization surgery for pediatric patients with moyamoya disease

OBJECTIVE

Transient neurological events (TNEs) are among the most important events after revascularization surgery in pediatric patients with moyamoya disease (MMD). Although hemodynamic changes and crying are representative factors of TNEs, brain compression by encephalomyosynangiosis (EMS) is another important cause of TNEs. Therefore, the authors assumed that making the EMS as thin as possible reduces the frequency of TNEs. However, thin-split EMS can lead to insufficient development of collateral vessels. This study aimed to evaluate the effects of thin-split EMS in combined revascularization surgery on postoperative outcomes in pediatric patients with MMD.

METHODS

The authors retrospectively included 56 consecutive combined revascularization surgeries in the anterior cerebral circulation in pediatric patients with MMD. These surgeries were classified into the former group and thin-split EMS group. The temporal muscle was halved in the former EMS group and split as thinly as possible in the thin-split EMS group. The authors performed between-group comparisons of postoperative stroke events and TNEs during the acute period and the development of collateral flow and stroke events during the chronic period.

RESULTS

Former and thin-split EMS procedures were performed in 37 and 19 patients, respectively. TNEs without crying or hemodynamic changes were observed significantly less frequently in the thin-split EMS group than in the former EMS group (0 [0.0%] in the thin-split EMS group vs 9 [24.3%] in the former EMS group, p = 0.021). There were no significant between-group differences in the development of indirect bypass during the chronic period (good: 34 [91.9%] and poor: 3 [8.1%] in the former EMS group vs good: 16 [84.2%] and poor: 3 [15.8%] in the thin-split EMS group; p = 0.397). Additionally, there were no significant between-group differences in the incidence of chronic clinical events, including death or stroke.

CONCLUSIONS

Thin-split EMS can reduce TNEs that do not accompany crying or hemodynamic changes. Furthermore, the procedure has sufficient prevention effects against stroke events during the chronic postoperative period in pediatric patients with MMD.