Moyamoya disease: A comparison of long term outcome of conservative and surgical treatment in India

Effect of Age, Stage, and Type of Surgical Revascularization on Clinical and Angiographic Outcome in Moyamoya Disease - Experience from a Case Series of 175 Revascularization Procedures

BACKGROUND

There is dearth of literature on impact of age - pediatric versus adult, Suzuki staging - early versus late, and revascularization type - indirect versus direct on clinical and angiographic outcome in moyamoya disease (MMD). Hence, we intend to comprehensively evaluate factors influencing outcome in MMD following surgical revascularization.

METHODS

MMD patients operated at our institute from January 2011 to August 2018 were followed for an average 24 months. Primary outcomes were modified Rankin score (mRS) and stroke risk reduction. Secondary outcome was angiographic outcome score (AOS).

RESULTS

A total of 133 patients including 37.6% adults (>18 years; n = 50) underwent 175 revascularizations - 89 direct (DR) and 86 indirect (IR) subgroups. Mean mRS scores improved in pediatric DR (P < 0.001), IR (P < 0.001), adult IR (P = 0.10), and DR (P = 0.25) subgroups. Recurrent stroke rate was similar in pediatric-DR (2.7%) and IR (7.6%, P = 0.61), and adult-DR (0%) and IR (4.1%) subgroups (P = 1.00). AOS scores improved in pediatric DR (P = 0.002) and IR (P = 0.01), and adult-DR (P = 0.02) and IR (P = 0.06) subgroups. Late-stage MMD (Suzuki IV-VI) showed better improvement in mRS scores than early-stage-Suzuki (I-III; P < 0.001). Recurrent stroke rates were similar (P = 0.26) and AOS scores improved significantly in early- and late-stage MMD (P < 0.001).

CONCLUSIONS

In pediatrics, clinical and angiographic outcome significantly improved after revascularization procedure, and in adults, angiographic improvement was more evident than clinical recovery. Late-stage Suzuki MMD patients demonstrated significantly better clinical improvement than early stage. The angiographic improvement was equivalent to early stage, irrespective of age and type of revascularization.

Epidemiology of Moyamoya Angiopathy in Eastern India

Introduction

Moyamoya angiopathy (MMA) is a chronic, progressive intracranial vasculopathy with variation in prevalence and clinical manifestations across different populations. This study was aimed to estimate the frequency of MMA as an etiology of stroke and its epidemiological features in the largest cohort of MMA patients in India.

Method

A single-centered cross-sectional observational study over a period of 5 years (2016–2021) was undertaken among consecutive stroke and transient ischemic attack (TIA) patients to look for the presence of MMA angiographically. Each patient with angiographically proven MMA was further evaluated for demographic, clinical, and radiological characteristics.

Results

Among 10,250 consecutive stroke and TIA patients (ischemic = 78%, hemorrhagic = 22%), frequency of MMA was 1.56% (n = 160); 15.3% among children. Female preponderance (Male:Female = 1:1.4) was noted among 160 MMA patients, with bimodal age distribution, first peak at 3–8 years, and a shorter second peak at 41–47 years. Childhood-onset MMA was seen in 75 (46.9%) with commonest initial neurological symptom of fixed-motor-weakness (44.0%), followed by TIA (26.7%); while 85 (53.1%) had adult-onset MMA with fixed-motor-weakness (50.6%) followed by headache (24.7%) as the predominant initial neurological symptom; seizure significantly higher in children (p < 0.001) and headache in adults (p = 0.012). Transient and fixed neurological manifestations constituted 87.5 and 69.4% respectively, of symptoms throughout the disease course. Cerebral infarction (45.0%) and TIA (21.9%) were the commonest types of MMA. On brain imaging, infarction was noted in 80.6%, hemorrhage in 11.3%, significantly higher among adults (p < 0.001). Cortical infarct and Gyral pattern were commoner in children (p = 0.004), subcortical infarcts in adults (p = 0.018). Frequent Suzuki staging observed was stage 4 (31.3%), followed by stage 3 (30.0%). Involvement of posterior circulation was detected in 55.6%, brain atrophy at the time of diagnosis was seen in 65.0%.

Conclusion

MMA is an important etiological consideration in patients with stroke, especially in children. It can present with a myriad of transient neurological symptoms, frequently overlooked, leading to delayed diagnosis, and contributing to socio-economic burden. Indian MMA showed aberrations in its gender predisposition, age distribution, frequency of familial cases, disease manifestation, and type of stroke, in comparison to its Japanese and Caucasian counterparts pointing to the inter- and intra-continent differences of MMA phenotype. Future development of the Indian MMA national registry is of essence.

The disease presentation of Moyamoya angiopathy in Eastern India

INTRODUCTION

Clinical spectrum of Moyamoya angiopathy (MMA) differs across populations with different ethnicity. This study, the largest one done among Indian population was undertaken to assess clinico-radiological profile of MMA patients in eastern India.

METHODS

A single centre cross-sectional study was undertaken among 76 MMA cases. Each patient was evaluated for epidemiological, clinical and radiological characteristics. SPSS 25 was used for statistical analysis. P < 0.05 was taken as statistically significant.

RESULTS

36 (47.4%) were children without gender preponderance. There were female predominance among adults (male:female = 1:2.33). Mean age at onset of first neurological symptoms for children was 4.2 ± 2.0years, followed by 34.9 ± 58.2months of latency with final diagnosis at the mean age of 7.4 ± 3.5years. For adults, mean age of onset of first neurological symptoms was 31.5 ± 12.3years, followed by 14.7 ± 41.7months time gap and diagnosed at the mean age of 33.5 ± 12.5years. There was a statistically significant difference between child and adult regarding the diagnostic latency (p = 0.035). Fixed motor weakness (FMW) was the predominant symptom across the whole disease course. Among children predominant first neurological symptom was fixed motor weakness (FMW) (52.8%), followed by seizures (22.2%). FMW was predominant (55%) first neurological complaint, followed by headache (22.5%) among adults. Seizure was more prevalent among children both as first (p = 0.002) and presenting symptom at the time of diagnosis (p = 0.048). Over the course of the disease seizure was more common among children (p = 0.001), while headache was more common among adults (p = 0.017). Recurrence of symptoms was more common among children (p = 0.059). Infarcts were more common among children (91.7%) than adults (72.5%), while hemorrhage was seen only among adults (25%) (p = 0.004). Isolated cerebral cortex was involved more commonly among children (59.4%) than adults (36.1%), while isolated subcortical involvement was seen only among adults (19.4%) (p = 0.016). Majority of the MMA cases were of Suzuki stage 4 (39.5%) and 5 (27.6%). Brain atrophy was associated with diagnostic latency (p = 0.009).

CONCLUSION

Indian Moyamoya presents similar to disease presentation in Caucasian and Japanese patients. It is a frequently overlooked cause of stroke in young, often with various non-motor presentations, failure to recognize which leads to delay in diagnosis. Radiological burden disproportionate to number of acute vascular events, with subtle neurological manifestations like headache or seizure, often with cognitive decline, should raise suspicion of MMA.

Results of more than 20 years of follow-up in pediatric patients with moyamoya disease undergoing pial synangiosis

OBJECTIVE

There are limited data on the long-term outcomes for children undergoing surgical revascularization for moyamoya disease (MMD) in North America. The authors present a series of pediatric MMD patients who underwent a standard revascularization procedure, pial synangiosis, more than 20 years previously at a single institution by a single surgical team.

METHODS

This study is a retrospective review of all patients aged 21 years or younger treated for MMD at Boston Children's Hospital who were operated on more than 20 years previously by the senior author (R.M.S.). Radiographic and operative reports, outpatient clinical records, and communications with patients and families were reviewed to document current clinical status, ability to perform daily activities, and concurrent or new medical conditions.

RESULTS

A total of 59 patients (38 female [64.4%], 21 male [35.6%]; median age at surgery 6.2 years [IQR 0.5-21 years]) were identified who were diagnosed with MMD and underwent surgical revascularization procedures more than 20 years previously. Clinically, all but 2 patients (96.6%) presented with the following symptoms alone or in combination: 43 (73%) presented with stroke, 22 (37%) with transient ischemic attack, 12 (20%) with seizures, 7 (12%) with headache, 3 (5%) with choreiform movements, and 2 (3%) with hemorrhage; MMD was incidentally detected in 2 patients (3%). Five patients had unilateral MMD at presentation, but 3 of these ultimately progressed to develop bilateral MMD after an average of 16 months; therefore, pial synangiosis was ultimately performed in a total of 116 hemispheres during the study period. Clinical follow-up was available at a median interval of 20.6 years (IQR 16.1-23.2 years). Modified Rankin Scale scores were stable or improved in 43 of 50 patients with evaluable data; 45 of 55 are currently independent. There were 6 patient deaths (10.2%; 3 due to intracranial hemorrhage, 2 due to tumor-related complications, and 1 due to pulmonary artery stenosis), 4 of whom had a history of previous cranial radiation. One patient (1.7%) experienced a late stroke. Synangiosis vessels remained patent on all available late MRI and MRA studies. Four patients reported uneventful pregnancies and vaginal deliveries years following their revascularization procedures.

CONCLUSIONS

Revascularization for MMD by pial synangiosis appears to confer protection from stroke for pediatric patients over long-term follow-up. A history of cranial radiation was present in 4 of the 6 patients who died and in the lone patient with late stroke. Most patients can expect productive, independent lives following revascularization surgery in the absence of significant preoperative neurological deficits and comorbidities.

Meta-Analysis of Prognosis of Different Treatments for Symptomatic Moyamoya Disease

OBJECTIVE

The purpose of this study was to evaluate the efficacy of surgical revascularization versus conservative treatment and different surgical modalities, in order to provide evidence for the patient with moyamoya disease (MMD) to choose the appropriate treatment.

METHODS

We comprehensively searched PubMed, Embase, Web of Science, and the Cochrane Library for articles published regarding MMD treatment. If the I² value, which evaluated the heterogeneity, was <50%, a fixed-effect model was used; if not, a random effect model was applied.

RESULTS

Twenty-seven articles were included in the meta-analysis. The surgery group is more advantageous in reducing the risk of future stroke events than conservative treatment in MMD patients (odds ratio [OR] 0.26, 95% confidence interval [CI] 0.20-0.33, P < 0.001). In addition, the surgical group also had an advantage in terms of increased cerebral perfusion (OR 7.16, 95% CI 3.28-15.64, P < 0.001) and death due to rebleeding (OR 0.27, 95% CI 0.10-0.72, P < 0.01). Direct surgery showed a significant efficacy over indirect surgery (OR 2.03, 95% CI 1.32-3.13, P < 0.01). No obvious difference was found between the direct and indirect bypass subset (OR 0.76, 95% CI 0.51-1.14, P = 0.185). Angiographic results in patients undergoing direct bypass surgery are more pronounced (OR 0.20, 95% CI 0.06-0.67, P < 0.01).

CONCLUSIONS

In patients with symptomatic moyamoya disease, bypass surgery is more effective than conservative treatment to prevent future strokes. In surgical patients, direct bypass seems to reduce the risk of stroke more than an indirect bypass.

Direct versus indirect bypasses for adult ischemic-type moyamoya disease: a propensity score–matched analysis

OBJECTIVE

The optimal surgical modality for moyamoya disease (MMD) remains unclear. The aim of this study was to compare the surgical effects of direct bypass (DB) and indirect bypass (IB) in the treatment of adult ischemic-type MMD.

METHODS

Adult patients with ischemic-type MMD who underwent either DB or IB from 2009 to 2015 were identified retrospectively from a prospective database. Patients lost to follow-up or with a follow-up period less than 12 months were excluded. Recurrent stroke events and modified Rankin Scale (mRS) scores at the last follow-up were compared between the 2 surgical groups after 1:1 propensity score matching.

RESULTS

A total of 220 patients were considered, including 143 patients who underwent DB and 77 patients who underwent IB. After propensity score matching, 70 pairs were obtained. The median follow-up period was 40.5 months (range 14–75 months) in the DB group and 31.5 months (range 14–71 months) in the IB group (p = 0.004). Kaplan-Meier analysis showed that patients who received DB had a longer stroke-free time (mean 72.1 months) compared with patients who received IB (mean 61.0 months) (p = 0.045). Good neurological status (mRS score ≤ 2) was achieved in 64 patients in the DB group (91.4%) and 66 patients in the IB group (94.3%), but there was no significant difference (p = 0.512).

CONCLUSIONS

Although neurological function outcome was not determined by the surgical modality, DB is more effective in preventing recurrent ischemic strokes than IB for adult ischemic-type MMD.

Moyamoya Vasculopathy in Indian Children: Our Experience

Background:

Moyamoya vasculopathy is a chronic progressive vaso-occlusive disease affecting the distal intracranial carotid arteries and their proximal branches. It is an important cause of recurrent strokes in children. Surgical revascularization procedures are now considered as the treatment option for moyamoya vasculopathy. The data from Indian children with moyamoya vasculopathy are limited to a very few studies.

Study Design:

We analyzed the records of children with moyamoya vasculopathy treated at our tertiary care center from 2000 to 2014. Our study population included all patients (aged 0–18 years) with moyamoya disease/syndrome (MMD/MMS). The demographic data, clinical characteristics, imaging, treatment details, and surgical procedures performed were reviewed.

Results:

A total of 41 patients (females-19, males-22) were identified. Thirty-three (80.48%) had MMD and eight (19.5%) had MMS. The mean age (±standard deviation) at presentation was 6.26 ± 3.79 years (range: 6 months–14 years). Majority had ischemic events at onset; none had hemorrhagic manifestations. Twenty-eight (68.29%) patients underwent surgery (a total of 33 surgical procedures, bilateral in five and unilateral in 23) and 13 (31.7%) were managed conservatively. The median duration of follow-up was 2.2 ± 1.85 years (range: 4 months–7 years). Two/thirteen patients (15%), who were managed conservatively, had recurrent strokes as against none (0/28) in the operated patients. No mortality was observed in our cohort.

Conclusion:

We agree with previous studies that Indian patients with moyamoya vasculopathy differ from their Asian and European counterparts. The availability of expertise in revascularization surgeries in various centers should prompt surgery as an efficient and safe treatment option.

Bypass surgery versus medical treatment for symptomatic moyamoya disease in adults

OBJECTIVE

In this study the authors evaluated whether extracranial-intracranial bypass surgery can prevent stroke occurrence and decrease mortality in adult patients with symptomatic moyamoya disease (MMD).

METHODS

The medical records of 249 consecutive adult patients with symptomatic MMD that was confirmed by digital subtraction angiography between 2002 and 2011 at 8 institutions were retrospectively reviewed. The study outcomes of stroke recurrence as a primary event and death during the 6-year follow-up and perioperative complications within 30 days as secondary events were compared between the bypass and medical treatment groups.

RESULTS

The bypass group comprised 158 (63.5%) patients, and the medical treatment group comprised 91 (36.5%) patients. For 249 adult patients with MMD, bypass surgery showed an HR of 0.48 (95% CI 0.27–0.86, p = 0.014) for stroke recurrence calculated by Cox regression analysis. However, for the 153 patients with ischemic MMD, the HR of bypass surgery for stroke recurrence was 1.07 (95% CI 0.43–2.66, p = 0.887). For the 96 patients with hemorrhagic MMD, the multivariable adjusted HR of bypass surgery for stroke recurrence was 0.18 (95% CI 0.06–0.49, p = 0.001). For the treatment modality, indirect bypass and direct bypass (or combined bypass) did not show any significant difference for stroke recurrence, perioperative stroke, or mortality (log rank; p = 0.524, p = 0.828, and p = 0.616, respectively).

CONCLUSIONS

During the treatment of symptomatic MMD in adults, bypass surgery reduces stroke recurrence for the hemorrhagic type, but it does not do so for the ischemic type. The best choice of bypass methods in adult patients with MMD is uncertain. In adult ischemic MMD, a prospective randomized study to evaluate the effectiveness and safety of bypass surgery to prevent recurrent stroke is necessary.

Effects of different surgical modalities on the clinical outcome of patients with moyamoya disease: a prospective cohort study

OBJECTIVE Bypass surgery is the most common treatment for moyamoya disease (MMD), but there is controversy over which surgical modality is best. The objective of this study was to evaluate the clinical outcome of patients with MMD after undergoing different surgical modalities. METHODS A series of 696 consecutive MMD patients treated between June 2009 and May 2015 were screened in this prospective cohort study. Patients who did not undergo revascularization surgeries and those who underwent different surgical modalities in bilateral hemispheres were excluded. Finally, 529 patients who were observed for at least 12 months were included: 438 patients underwent unilateral surgery, and 91 patients underwent bilateral surgery. Of these, 241 patients underwent direct bypass (DB); 81, a combined bypass (CB); and 207, an indirect bypass (IB). Three clinical outcomes were evaluated and compared between surgical groups: recurrent stroke events, modified Rankin Scale (mRS) scores, and change in the main symptoms. RESULTS The mean follow-up period was 40 months. During the follow-up period, recurrent stroke was observed in 43 patients, including 15 patients with hemorrhage, 26 patients with ischemia (transient ischemic attack in 19 patients and infarction in 7 patients), and 2 patients with both hemorrhage and cerebral infarction. Kaplan-Meier analysis showed that patients who underwent a CB or DB had a longer ischemia-free time than those who underwent IB (p = 0.013); however, there was no significant difference in the hemorrhage-free time between the different surgical modalities (p = 0.534). A good neurological status (mRS score ≤ 2) was achieved in 495 patients (93.6%) and was significantly achieved by more children (98.2%) than adults (92.3%; p = 0.022). Surgical modalities were not significantly associated with outcome neurological status (p = 0.860). Moreover, improvement in symptoms was observed in 449 patients (84.9%) and was also significantly more common in children (93.0%) than in adults (82.7%; p = 0.006). No significant difference was observed between the different surgical modalities (p = 0.548). CONCLUSIONS CB and DB are more effective at preventing recurrent ischemic strokes than IB. However, there is no evidence that these 3 surgical modalities demonstrate significant differences in preventing recurrent hemorrhage.

The Efficacy of Surgical Treatment for the Secondary Prevention of Stroke in Symptomatic Moyamoya Disease: A Meta-Analysis

The treatment of moyamoya disease (MMD) is controversial and often depends on the doctor's experience. In addition, the choice of surgical procedure to treat MMD can differ in many ways. In this study, we performed a meta-analysis to determine whether surgical treatment of MMD is superior to conservative treatment and to provide evidence for the selection of an appropriate surgical treatment.The human case-control studies regarding the association of MMD treatment were systematically identified through online databases (PubMed, Web of Science, Elsevier Science Direct, and Springer Link). Inclusion and exclusion criteria were defined for the eligible studies. The fixed-effects model was performed when homogeneity was indicated. Alternatively, the random-effects model was utilized.This meta-analysis included 16 studies. Surgical treatment significantly reduced the risk of stroke (odds ratio (OR) of 0.17, 95% confidence interval (CI), 0.12-0.26, P < 0.01). A subgroup analysis showed that surgical treatment was more beneficial to hemorrhagic MMD (OR of 0.23, 95% CI, 0.15-0.38, P < 0.01), but there was no significant difference between surgical treatment and conservative treatment on ischemic MMD treatment (OR of 0.45, 95% CI, 0.15-1.29, P = 0.14). Further analysis indicated that compared to direct bypass surgery, indirect bypass surgery had a lower efficacy on secondary stroke risk reduction (OR of 1.79, 95% CI, 1.14-2.82, P = 0.01), while no significant difference was detected for perioperative complications.Surgery is an effective treatment for symptomatic MMD patients, and direct bypass surgery may bring more benefits for these patients.