Postoperative cerebral infarction after revascularization in patients with moyamoya disease: Incidence and risk factors

Introducing an index on prediction of post-revascularization cerebral infarction using preoperative CT perfusion parameters in moyamoya disease

OBJECTIVE

To determine the value of preoperative CT perfusion (CTP) parameters for prediction of post-revascularization cerebral infarction (post-CI) in adults with moyamoya disease (MMD).

METHODS

This retrospective study included 92 adults with MMD who underwent surgical revascularization. Preoperative quantitative CTP parameters, including cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to drain (TTD), and transit time to maximum of the residue function (Tmax), along with clinical data, were compared between the groups with and without post-CI. Predictors of post-CI were identified and assessed using multivariable logistic regression and receiver-operating characteristic curve analyses.

RESULTS

Post-CI occurred in 11 patients (12.0%). In univariate analysis, preoperative mean values for CBF, MTT, TTD, Tmax, initial presentation, infarction within the 2 months before surgery, surgical side, and modified Rankin Scale score on admission were associated with post-CI (all p < 0.05). Multivariable logistic regression revealed that the preoperative mean Tmax (OR 2.342, 95% CI: 1.267-4.330, p = 0.007) and infarction within the 2 months before surgery (OR 14.345, 95% CI: 2.108-97.638, p = 0.006) were independent predictors of post-CI. The preoperative mean Tmax produced the largest area under the curve (0.955, 95% CI: 0.914-0.997) with a cutoff of 3.590 s (sensitivity, 100%; specificity, 87.7%).

CONCLUSIONS

Adults with MMD are at risk of post-CI when the preoperative mean Tmax is > 3.590 s. Cerebral infarction during the 2 months before revascularization is also a risk factor for post-CI.

CRITICAL RELEVANCE STATEMENT

Post-CI is a serious complication for adults with MMD following surgical revascularization. The risk of post-CI can be predicted using preoperative CTP parameters, which will assist neurosurgeons with surgical decisions and implementing individualized prophylactic strategies.

KEY POINTS

Predicting the risk of post-CI in MMD patients is beneficial to their prognosis. The preoperative mean Tmax was an excellent perfusion parameter for predicting post-CI. Preoperative CTP evaluation can help clinicians make cautious surgical decisions.

Prediction of cerebral infarction after bypass surgery in adult moyamoya disease: combing parameters on 4D perfusion CT with clinical related factors

OBJECTIVE

This study aimed to identify predictive factors for cerebral infarction after bypass surgery in adult patients with moyamoya disease (MMD) using quantitative parameters in 4D-CT perfusion software.

METHODS

A total of 108 patients who underwent combined revascularization, including superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS), in our hospital between September 2019 and August 2023 were analyzed retrospectively. Preoperative relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative time to maximum residual function (rTmax) perfusion parameters were obtained using 4D-CT perfusion software. These quantitative parameters, combined with related clinical and angiographic factors, were statistically analyzed using univariate and multivariate regression analyses to determine the significant predictors of cerebral infarction after bypass surgery.

RESULTS

Acute cerebral infarction occurred in 12 patients postoperatively. Univariate analysis showed that a history of previous ischemic events (P = 0.024), higher Suzuki stage (P = 0.006), higher modified Rankin score (mRS) (P = 0.013), rCBV (P = 0.026), rMTT (P = 0.001), and rTmax (P < 0.001) were associated with postoperative cerebral infarction. Further multivariate regression analysis showed that a history of previous ischemic events (OR = 12.830, 95%CI = 1.854-875.672, P = 0.031) and higher rTmax (OR = 16.968, 95%CI = 2.035-141.451, P = 0.009) were independently associated with new postoperative cerebral infarction. The cutoff value for rTmax was 2.025 (AUC = 0.935).

CONCLUSIONS

Previous ischemic event history and rTmax greater than 2.025 are independent risk factors for predicting cerebral infarction after combined revascularization with high sensitivity in adult patients with MMD. These patients should be more cautious when deciding on combined revascularization.

Coincidence of Concentric Vessel-Wall Contrast Enhancement in Moyamoya Disease and Acute Postoperative Ischemic Stroke During Revascularization Procedures

BACKGROUND

Concentric vessel-wall contrast enhancement (VW-CE) of the terminal carotid artery and its proximal branches may be linked to ischemic strokes, disease activity and progression in Moyamoya disease (MMD). The objective of this retrospective cohort study is to analyze the association between VW-CE and perioperative acute ischemic stroke (PAIS) occurring within 24 h after revascularization.

METHODS

All previously untreated MMD patients who required revascularization and who had undergone preoperative MRI with VW-CE-sequences were included. PAIS was detected by CT and/or diffusion-weighted MRI sequences within 24 h postoperatively.

RESULTS

Of the 110 patients included (female-to-male ratio: 2.7:1, median age: 45.1 (16.6-69.2); n = 247 revascularizations), a priori VW-CE was present in 67.3% (mean time from MRI to first surgery: 86 days ± 82 days). PAIS occurred in five patients undergoing primary revascularization (PAIS rate per revascularization: 2.1%), all of whom had a preoperative pathological VW-CE in the vascular segment corresponding to the stroke area. Two (40%) incidents of PAIS occurred in revascularized territory, while three (60%) occurred in non-revascularized vascular territory. In each case, the supplying artery exhibited VW-CE, indicating disease activity. No additional PAIS occurred during subsequent revascularizations in cases of multistage procedures (n = 38), such as ACA or PCA revascularization as a second step.

CONCLUSIONS

Preoperative VW-CE in one or more vascular segments may be a marker for postoperative stroke in the respective vascular territory at the time of revascularization. VW-CE imaging should be routinely performed when planning revascularization in MMD. If VW-CE is found, strict perioperative monitoring of these high-risk patients should be performed to achieve the best results possible.

Natural course of hemodynamically stable hemispheres contralateral to operated hemispheres in adult patients with ischemic moyamoya diseases

The necessity of bilateral bypass in adult moyamoya disease (MMD) remains unclear despite its recommendation for pediatric and hemorrhagic cases. We aimed to investigate the natural course of hemodynamically stable unoperated hemispheres after bypass surgery for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD. Among 288 patients, the mean age at the first operation of the unstable hemispheres was 40.8 ± 12.2 years. The mean follow-up period was 62.9 ± 46.5 months. 45 patients (15.6%) experienced stroke events in the unoperated hemisphere, consisting of hemorrhagic stroke in 8 (2.8%) and ischemic stroke in 37 (12.8%), including progressive transient ischemic attack in 25 (8.7%) and infarction in 12 (4.2%). Among them, 39 patients (13.5%) underwent bypass surgery. The annual risk of total stroke is 3.0%/patient-year, with 2.5% for ischemic stroke and 0.5% for hemorrhagic stroke. The 5- and 10-year cumulative risks of ischemic stroke were 13.4% and 18.3%, respectively, and those of hemorrhagic stroke were each 3.2%. The natural course of hemodynamically stable hemispheres contralateral to the operated ones appeared fairly good. Additional bypass surgery on the unoperated hemispheres should be considered for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD during the follow-up.

Clinical Characteristics of Immediate Contralateral Ischemia Subsequent to Revascularization for Moyamoya Disease

BACKGROUND

Moyamoya disease is a bilateral steno-occlusive disease involving the cerebral vasculature. While some patients are affected by procedure-related ipsilateral ischemia, ischemic complications contralateral to the revascularization are rarely observed.

METHODS

We retrospectively investigated 135 hemispheres (103 patients) that underwent revascularization in our institution between April 2006 and September 2022. Revascularization surgery comprised single superficial temporal artery-middle cerebral artery anastomosis and encephalo-myo-synangiosis. Certain patients aged under 10 years underwent indirect revascularization. Bilateral revascularization was performed with an interval of >3 months. Medical records and neuroimages were reviewed, and patients with contralateral ischemic complications were identified. Some cases underwent genetic analysis.

RESULTS

The mean age was 34.5 (range: 5-71) years, and 95 cases (70.4%) were in women. Of the 102 cases examined for the RNF213 c.14429 G > A (p.Arg4810Lys) variant, 33 (32.4%) and 69 (67.6%) showed the GG and GA genotype, respectively. Three cases (2.2%, all female, age range 44-71 years) were complicated with contralateral infarction. The infarcted area distributions of the 2 cases with RNF213 c.14429 G > A variant were patchy and peripheral. The other case showed on magnetic resonance imaging (MRI) angiography total occlusion of the internal carotid artery where patency had been confirmed preoperatively.

CONCLUSIONS

Contralateral ischemia after revascularization occurred in 2.2% of cases. We classified them into peripheral and central types: peripheral type, an infarction owing to hemodynamic insufficiency or intracranial blood flow redistribution; central type, total occlusion of the contralateral internal carotid artery. Intensive preoperative management can minimize the risk of peripheral types, and neurosurgeons should beware of severe central types.

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.

Clinical effect of a modified superficial temporal artery-middle cerebral artery bypass surgery in Moyamoya disease treatment

Background

Cerebral extracranial-intracranial (EC-IC) revascularization technique (superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting) has become the preferred surgical method for the treatment of Moyamoya disease (MMD). We attempted to completely free the two branches of the superficial temporal artery without disconnection. Extracranial and intracranial blood flow reconstruction were then modified by selectively performing a direct bypass technique on one branch and a patch fusion technique on the other of the STA based on the blood flow and the vascular diameter of the intracranial surface blood vessels.

Methods

A series of modified STA-MCA bypass surgeries performed consecutively between March 2022 and March 2023 were reviewed and compared to conventional combined bypass surgeries performed during the same period. The following information was collected from all enrolled patients: demographic characteristics, clinical symptoms, and preoperative and postoperative imaging, including Suzuki stage and Matsushima grade. The modified Rankin scale (mRS) was used to assess the changes in neurological status before and after surgery.

Results

A total of 41 patients with Moyamoya disease (MMD) who underwent cerebral revascularization were included in this study, of which 30 were conventional revascularization and 11 were modified revascularization. The mean age was 49.91 years, and 18 (43.9%) of the patients were women. The modified group had a lower incidence of cerebral hyperperfusion syndrome (18.2%) than the conventional group (23.3%). After at least 3 months of follow-up, the bypass patency rate remained 100% in the modified group and 93.3% in the conventional group. All patients in the modified group achieved a better Matsushima grade (A + B), with six (54.5%) having an A and five (45.5%) having a B. In contrast, four patients (13.3%) in the conventional group had a Matsushima grade of C. In all, 72.8% of the modified group had postoperative mRS scores of 0 and 1, which was higher than that of the traditional group (63.3%).

Conclusion

The improved STA-MCA bypass could provide blood flow to multiple cerebral ischemic areas, reduce excessive blood perfusion, and ensure blood supply to the scalp, with lower complications and better clinical benefits than the traditional combined bypass.