Safety and Efficacy of Induced Hypertension and Hypervolemia in Preventing Neurologic Complications After Combined Direct and Indirect Bypass in Hemorrhagic-Onset Moyamoya Disease

Incidence and Outcomes of Posterior Circulation Involvement in Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a progressive, occlusive disease of the internal carotid arteries and their proximal branches, with the subsequent development of an abnormal vascular network that is rupture-prone. Steno-occlusive changes in the posterior cerebral arteries (PCAs) may contribute to worsened outcomes in patients with MMD; however, there is little information on the incidence and natural history of posterior circulation MMD (PCMMD). We describe clinical PCMMD characteristics in a large cohort of patients with MMD.

METHODS

We retrospectively reviewed patients with MMD treated between 1991 and 2019 at a large academic medical center. Demographics, perioperative outcomes, and radiological phenotypes were recorded for 770 patients. PCA disease was graded as either 0 (no disease), 1 (mild), 2 (moderate), or 3 (severe or occluded) based on cerebral angiography. Patients with angiographically confirmed MMD diagnosis with at least 6 months follow-up and completion of revascularization surgery were included; patients with intracranial atherosclerosis, intracranial dissection, vasculitis, and undefined inflammatory processes were excluded. The presence of stenosis/occlusion was graded radiographically to assess for disease progression and the prevalence of risk factors related to reduced progression-free survival.

RESULTS

In all, 686 patients met the inclusion criteria, with PCA disease identified in 282 (41.1%) patients. Of those 282 patients with PCMMD, disease severity ranged from 99 (35.1%) with mild, 72 (25.5%) with moderate, and 111 (39.4%) with severe. The total number of postoperative complications was significantly associated with PCMMD severity (P=0.0067). Additionally, PCMMD severity correlated with worse postoperative modified Rankin Scale scores (P<0.0001). At a mean follow-up of 6.0±3.9 (range, 0.1-25.0) years, a total of 60 (12.6%) patients showed new/worsening PCMMD. The overall postoperative, progression-free survival in patients with PCMMD was 95.4% at 1 year, 82.4% at 3 years, 68.8% at 5 years, and 28.3% at 10 years, with prognostic factors for progression including preoperative PCMMD status, history of tobacco use, and hypertension (P<0.0001, P<0.001, and P<0.0001, respectively).

CONCLUSIONS

PCA disease involvement in MMD is associated with higher rates of ischemic perioperative complications and worsened functional outcomes, likely due to reduced collateral flow. Ten-year progression of PCA disease is highly likely and should be monitored throughout follow-up; future studies will assess the impact of PCA disease progression on long-term outcomes.

Relative anemia and perioperative stroke in children with moyamoya

OBJECTIVES

Surgical revascularization for moyamoya arteriopathy decreases long-term stroke risk but carries a risk of perioperative ischemic complications. We aimed to evaluate modifiable stroke risk factors in children undergoing surgical revascularization for moyamoya.

MATERIALS AND METHODS

In this exploratory, single-center, retrospective cohort study, medical records of pediatric patients undergoing surgical revascularization for moyamoya arteriopathy at our center between 2003 and 2021 were reviewed. Candidate modifiable risk factors were analyzed for association with perioperative stroke, defined as ischemic stroke ≤7 days after surgery.

RESULTS

We analyzed 53 surgeries, consisting of 39 individual patients undergoing indirect surgical revascularization of 74 hemispheres. Perioperative ischemic stroke occurred following five surgeries (9.4%). There were no instances of hemorrhagic stroke. Larger pre-to-postoperative decreases in hemoglobin (OR 3.90, p=0.017), hematocrit (OR 1.69, p=0.012) and blood urea nitrogen (OR 1.83, p=0.010) were associated with increased risk of perioperative ischemic stroke. Weight-adjusted intraoperative blood loss was not associated with risk of perioperative ischemic stroke (OR 0.94, p=0.796). Among children with sickle cell disease, all of whom underwent exchange transfusion within one week prior to surgery, none experienced perioperative stroke.

CONCLUSIONS

Decreases in hemoglobin, hematocrit, and blood urea nitrogen between the preoperative and postoperative periods are associated with increased risk of perioperative stroke. These novel findings suggest that dilutional anemia, possibly due to standardly administered hyperhydration, may increase the risk of perioperative stroke in some children with moyamoya. Further work optimizing both mean arterial pressure and oxygen-carrying capacity in these patients, including consideration of alternative blood transfusion thresholds, is necessary.

Clinical Features and Risk Factors of Postoperative Stroke in Adult Moyamoya Disease

BACKGROUND AND PURPOSE

The clinical features of and risk factors for postoperative stroke after surgical revascularization in adult moyamoya disease (MMD) have not been fully elucidated. To this end, the baseline clinical features were hereby described, and the risk factors for postoperative stroke were determined.

METHODS

Data of 4078 MMD inpatients were collected retrospectively across all secondary- and higher-level hospitals of Hubei Province from January 2019 to December 2020. In accordance with inclusion and exclusion criteria, 559 adult MMD inpatients were finally enrolled. The associated characteristics and potential risk factors were analyzed, and the Kaplan-Meier risk of stroke was also calculated.

RESULTS

The patients consisted of 286 females and 273 males, with a mean age of 49.1 ± 10.0 years, all of whom had at least 1 year of follow-up (median 25.1 months). There were 356 cases of preoperative ischemic symptoms and 203 cases of preoperative hemorrhage symptoms. Indirect, direct, and combined revascularization were conducted on 97, 105 and 357 patients, respectively. Among these patients, 17 had postoperative hemorrhagic stroke (PHS), and 43 had postoperative ischemic stroke (PIS). A comparison between PHS/PIS group and control group (patients without postoperative stroke events) showed that preoperative hemorrhage was significantly associated with PHS (p = 0.003), while hypertension (p = 0.003), diabetes mellitus (p = 0.003) and modified Rankin scale (mRS) (p = 0.034) at admission were associated with a higher rate of PIS. Furthermore, preoperative hemorrhagic stroke was identified as a risk factor for PHS (odds ratio [OR], 4.229 [95% CI, 1.244-14.376]; p = 0.021), while hypertension (odds ratio [OR], 0.424 [95% CI, 0.210-0.855]; p = 0.017), diabetes mellitus (odds ratio [OR], 0.368 [95% CI, 0.163-0.827]; p = 0.016) and admission mRS (odds ratio [OR], 2.301 [95% CI, 1.157-4.575]; p = 0.017) were found to be risk factors for PIS.

CONCLUSIONS

The age distribution of adult MMD patients with revascularization was predominantly concentrated within the range from 46 to 55 years. Preoperative hemorrhage events were considered the risk factor for PHS. Hypertension, diabetes and admission mRS were correlated with PIS, and were also the risk factors for PIS. These results indicated the possible contribution of enhancing systematic disease management to the prevention of postoperative cerebrovascular accidents.

Screening of postoperative cerebral hyperperfusion syndrome in moyamoya disease: a three-dimensional pulsed arterial-spin labeling magnetic resonance imaging approach

Introduction

Moyamoya disease (MMD) is associated with a risk of postoperative cerebral hyperperfusion syndrome (CHS) after revascularization surgery. This study aimed to explore the feasibility of using three-dimensional pulsed arterial spin labeling (3D PASL) and phase contrast (PC) magnetic resonance imaging (MRI) for predicting CHS occurrence in patients with MMD before revascularization surgery.

Methods

Overall, 191 adult patients (207 hemispheres) with MMD who underwent combined revascularization surgery were included in this study. Preoperative 3D PASL-MRI and PC-MRI were performed before surgery. The PASL-MRI data were analyzed using SPM12. Patient clinical information, average flow, and preoperative cerebral blood flow (CBF) were compared between the non-CHS and CHS groups.

Results

Among the patients, 45 (21.74%) developed CHS after revascularization surgery. No significant differences were noted in age, sex, clinical symptoms, hypertension, diabetes, surgical side, or history of revascularization surgery between the non-CHS and CHS groups. However, the average flow in the superficial temporal artery was significantly lower in the CHS group than in the non-CHS group (p < 0.05). Furthermore, 11 clusters of preoperative CBF values were significantly greater in the CHS group than in the non-CHS group [p < 0.05, false discovery rate (FDR) corrected]. A significant correlation was also observed between the preoperative time-to-flight MR angiography (MRA) scores and CBF values in patients with MMD (p < 0.05).

Conclusion

Compare patients with lower preoperative CBF and higher preoperative average flow in the STA, patients with higher preoperative CBF and lower preoperative average flow in the STA are more likely to develop postoperative CHS Preoperative PASL-MRI and PC-MRI examinations may help to screen patients at high risk of developing CHS after revascularization surgery.