Unstable moyamoya disease: clinical features and impact on perioperative ischemic complications

Abstract

A mAjor characteristic of moyamoya disease is the chronic progression of stenosis in the terminal portion of the internal carotid artery (ICA). 24 The rate of this progression varies by patient. Angiographic progression can occur in one-half of pediatric patients and one-quarter of adult patients, 19,21 while angiographic findings in the remaining patients are stable for years. Some patients demonstrate extremely rapid progression from disease onset, resulting in poor outcome. obJect Unstable moyamoya disease, reasonably defined as cases exhibiting either rapid disease progression or repeated ischemic stroke, represents a challenge in the treatment of moyamoya disease. Despite its overall efficacy, direct bypass for such unstable disease remains controversial in terms of safety. This study aims to reveal factors associated with unstable disease and to assess its impact on postoperative silent or symptomatic ischemic lesions. methods This retrospective cohort study included both pediatric and adult patients with moyamoya disease who had undergone 140 consecutive direct bypass procedures at Kyoto University Hospital. "Unstable moyamoya disease" was defined as either the rapid progression of a steno-occlusive lesion or repeat ischemic stroke, either occurring within 6 months of surgery. The extent of progression was determined through a comparison of the findings between 2 different MR angiography sessions performed before surgery. The clinical variables of the stable and unstable disease groups were compared, and the association between unstable disease and postoperative diffusion-weighted imaging (DWI)-detected lesion was assessed through univariate and multivariate analyses with generalized estimating equations. results Of 134 direct bypass procedures performed after patients had undergone at least 2 sessions of MR angiography, 24 (17.9%) were classified as cases of unstable disease. Age younger than 3 years (p = 0.029), underlying disease causing moyamoya syndrome (p = 0.049), and radiographic evidence of infarction (p = 0.030) were identified as factors associated with unstable disease. Postoperative DWI-defined lesions were detected after 13 of 140 procedures (9.3%), although only 4 lesions (2.9%) could be classified as a permanent complication. coNclusioNs Unstable moyamoya disease, more prevalent in younger patients and those with underlying disease, is a possible risk factor for perioperative ischemic complications. Recognition of unstable moyamoya disease may contribute to an improved surgical result through focused perioperative management based on appropriate surgical risk stratification.

Moyamoya Disease: Treatment and Outcomes

“…Funaki et al reported that postoperative diffusion weighted imaging (DWI)-defined lesions were detected in 13 (9.3%) out of 140 direct bypass operations for MMD, although only four lesions (2.9%) could be classified as a permanent complication. However, the incidence of postoperative DWI-detected lesions in the unstable group was significant at 33.3% (8 of 24) [ 50 ]. These peri-operative ischemic complications can be caused by several factors.…”

Progress on Complications of Direct Bypass for Moyamoya Disease

“…MMD is pathophysiologically complex. Fragile MMD vessels and unstable hemodynamics result in a very high surgical risk, and direct bypass is associated with a high incidence of surgical complications, especially in patients with unstable MMD 14 , 15 . In 2005, Kim et al found that MMD surgery performed within 6 weeks after the last ischemic infarction resulted in a higher incidence of postoperative ischemic complications 16 .…”

Histopathological Characteristics of Distal Middle Cerebral Artery in Adult and Pediatric Patients with Moyamoya Disease

“… 16 , 17) Younger patients and underlying disease have been reported predisposition factors of rapid progression of MMD. 18) …”