Adolescents with moyamoya disease: clinical features, surgical treatment and long-term outcomes

BACKGROUND

This study aimed to elucidate the clinical features, surgical treatment and long-term outcomes of adolescent patients with moyamoya disease.

METHODS

We reviewed consecutive patients with moyamoya vasculopathy who were admitted to our hospital from 2009 to 2015 to identify adolescent patients with moyamoya disease. Clinical features, surgical treatment and long-term outcomes were analyzed. Follow-up was performed by face-to-face or structured telephone interviews. Outcome measures were future stroke events. We performed univariate and multivariate time-to-event analyses to identify risk factors associated with future stroke events.

RESULTS

A total of 95 adolescent patients with moyamoya disease (age at onset, 13.1 ± 2.3 years) were included in this study. During follow-up, 12 patients (12.6%) had stroke events. We found that the patients who underwent direct/combined bypass had a significantly lower risk of future strokes [hazard ratio (HR), 0.16; 95% confidence interval (CI), 0.03-0.74; P = 0.019] compared to patients who underwent indirect bypass.

CONCLUSIONS

Our results demonstrate that direct/combined bypass can be more effective in preventing future strokes than indirect bypass in adolescent patients with moyamoya disease.

Enlarged Encephalo-Duro-Myo-Synangiosis Treatment for Moyamoya Disease in Young Children

OBJECTIVE

To retrospectively evaluate the midterm therapeutic effect of enlarged encephalo-duro-myo-synangiosis (EDMS) for moyamoya disease (MMD) in young children.

METHODS

Seventy-seven children diagnosed with MMD by digital subtraction angiography (DSA) or magnetic resonance angiography (MRA) were treated between January 2011 and December 2014 in our center. Their clinical features, imaging, and operative reports were analyzed.

RESULTS

Four patients presented with intracerebral hemorrhage, whereas 73 presented with ischemic symptoms. Revascularization procedures were performed unilaterally on 11 left hemispheres and 9 right hemispheres, and 57 had bilateral surgeries. The average length of surgery was 143 ± 24 minutes, with 28 ± 9 mL of blood loss. The mean period of follow-up was 28.43 ± 15.31 months. Cerebral blood flow increased 3 months after the operations in the previously affected regions. Collateralization from the deep temporal artery, superficial temporal artery, and the middle meningeal artery was found by DSA or MRA. In cases where single-photon emission computed tomography was obtained, it demonstrated better perfusion postoperatively. The ischemic symptoms were relieved in 118 (88.06%) hemispheres, and remained stable in 5 (3.73%) hemispheres. There were 12 radiographic cerebral infarctions (8.96%) within 1 month postoperatively.

CONCLUSIONS

Enlarged EDMS is safe and effective for MMD in young children. Extensive and multilayered revascularization could significantly preserve neurologic function. The long-term effect on posterior circulation disease development needs further investigation.

Incidence, clinical features, and treatment of familial moyamoya in pediatric patients: a single-institution series

OBJECTIVE Limited data exist on familial moyamoya in children. The purpose of this study was to characterize presentation and outcomes of pediatric moyamoya patients who have relatives diagnosed with moyamoya. METHODS The authors performed a single-institution retrospective analysis of a case series including all surgically treated children with moyamoya with first- or second-degree relatives with moyamoya. Clinical and radiographic characteristics were analyzed, along with surgical outcomes. RESULTS A total of 537 patients underwent surgery for moyamoya during the study period. Eighteen of those patients (3.4% of the total series) had moyamoya and a family history of moyamoya and were included in this study. Of these 18 patients, 14 were non-twin siblings, and the remaining 4 represented 2 pairs of identical (affected) twins. The presentation was predominantly ischemic (72%), but 4 patients (33%) were asymptomatic when they were found to have moyamoya. Bilateral disease was present in 13 patients (72%). Radiographic stroke prevalence (67%), Suzuki grade (3.3), and angiographic findings were comparable to findings in nonfamilial moyamoya patients. Thirty revascularization procedures were performed, with a 3.3% operative stroke rate per hemisphere and no new strokes in an average follow-up period of 4.5 years. CONCLUSIONS In a North American surgical series, familial moyamoya existed in 3.4% of cases, and was distinguished by manifesting in a broad range of ethnic groups, with a higher proportion of male patients and increased rates of asymptomatic and unilateral disease in comparison to nonfamilial moyamoya. Screening indications remain controversial and the current data are used to suggest guidelines. Surgical therapy is warranted, effective, and durable in these patients, but patients should be carefully selected.

Ultrasonographic Changes after Indirect Revascularization Surgery in Pediatric Patients with Moyamoya Disease

The marked cerebral hypoperfusion of moyamoya disease (MMD) can be treated with encephaloduroarteriosynangiosis (EDAS), an indirect revascularization surgery. Collateral establishment after the surgery is a gradual process; thus, easy access to serial assessment is of great importance. We prospectively recruited 15 pediatric moyamoya patients who underwent EDAS surgeries on a total of 19 hemispheres. Ultrasonography of extracranial and intracranial arteries was performed pre-operatively and post-operatively at 1, 3 and 6 mo. Among the extracranial arteries, the superficial temporal artery had the most pronounced increase in flow velocity and decrease in flow resistance from 1 mo post-surgery (p < 0.01). Among the large intracranial arteries, a significant increase in peak systolic velocity was observed in the anterior cerebral artery from 3 mo post-surgery (p < 0.05). These findings indicate significant hemodynamic changes on ultrasonography in pediatric moyamoya patients after indirect revascularization surgery.

Moyamoya Disease: Treatment and Outcomes

Although the pathogenesis of moyamoya disease (MMD) has not been fully elucidated, the effectiveness of surgical revascularization in preventing stroke has been addressed by many studies. The main mechanism of surgical revascularization is augmenting the intracranial blood flow using an external carotid system by either direct bypass or pial synangiosis. This can improve resting cerebral blood flow as well as vascular reserve capacity. For direct revascularization, the superficial temporal artery is used as the donor artery in most cases, although the occipital artery may be used in limited cases. Usually, the cortical branch of the middle cerebral artery is selected as the recipient of direct anastomosis. As for indirect revascularization, various techniques using different kinds of connective tissues have been introduced. In some cases, reinforcing the anterior cerebral artery and the posterior cerebral artery territories can be considered. The effectiveness of surgical revascularization for preventing ischemic stroke had been generally accepted by many studies. However, for preventing hemorrhagic stroke, new evidence has been added by a recent randomized controlled trial. The incidence of peri-operative complications such as stroke and hyperperfusion syndrome seems to be high due to the nature of the disease and technical demands for treatment. Preventing and adequately managing these complications are essential for ensuring the benefits of surgery.

Surgical outcomes following encephaloduroarteriosynangiosis in adult moyamoya disease associated with Type 2 diabetes

OBJECTIVE Debate exists regarding the merits and shortcomings of an indirect bypass procedure for treating adult patients with moyamoya disease (MMD). Considerable variation in neovascularization occurs among different organs in patients with diabetes mellitus. Here, the effect of encephaloduroarteriosynangiosis on MMD associated with Type 2 diabetes mellitus (T2DM) is evaluated. METHODS A retrospective and 1:2 matched case-control study was conducted in moyamoya patients with or without T2DM (n = 180). Postoperative collateral formations were graded according to the Modified Collateral Grading System that originated from the Matsushima Angiographic Stage Classification. Neurological function outcomes before and after the operation were evaluated according to the modified Rankin Scale. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for clinical outcome. RESULTS There was no statistically significant difference in the constituent ratios of initial symptom and preoperative Suzuki stage between patients with and without T2DM. Progression of angiopathy around the circle of Willis was postoperatively observed in bilateral internal carotid arteries in both groups. Patients with T2DM had a higher postoperative Suzuki stage (p < 0.01) and more frequent development of collateral angiogenesis germinating from the external carotid after indirect revascularization procedures in the surgical cerebral hemisphere (82.7% vs 72.2%; p < 0.05). The extent of postoperative collateral formation in patients with diabetes mellitus was significantly higher (p < 0.01). Postoperative clinical improvement in the diabetes group was more common after revascularization procedures (p < 0.05), and the diabetes group had lower modified Rankin Scale scores (p < 0.05) in comparison with the nondiabetes group. Late postoperative stroke and posterior cerebral artery involvement were identified as predictors of unfavorable clinical outcome in both groups, while T2DM was associated with a favorable clinical outcome. CONCLUSIONS Encephaloduroarteriosynangiosis is an efficacious treatment for adult patients with MMD. Patients with T2DM could achieve better collateral circulation and clinical improvement following surgery.

Universal Bypass for Treatment of Symptomatic Moyamoya Disease or Moyamoya Syndrome. Analysis of a Personal Case Series on Behalf of the Italian Moyamoya Association

BACKGROUND

Moyamoya (MM) is a very rare cerebrovascular disease, particularly in Caucasians. We describe the results of an Italian case series where the mainstay of treatment was a bypass or a combined approach.

METHODS

An analysis of a prospectively collected database was carried out. The main objective was to investigate (1) the risk of perioperative stroke and surgical complications, (2) the risk of new ischemic events, and (3) the risk of new hemorrhages at follow-up (mean follow-up: 2.2 years).

RESULTS

Between January 2011 and January 2015 we carried out 34 bypasses in 23 patients with MM (15 MM disease, 5 unilateral MM, 3 MM syndrome); mean age was 34 (range:1-57). The mortality and definitive morbidity rates were 0 %. Two patients suffered from transient aphasia and one developed partial palsy of the facial nerve. Five of the 12 patients with preoperative fixed deficits improved. No patient with preoperative ischemia experienced new ischemic symptoms. Rebleeding occurred in 1 of the 11 patients with a hemorrhagic presentation (9 %).

CONCLUSIONS

The bypass/combined approach to MM appears to have a favorable risk profile and preventive effectiveness, particularly on TIAs and ischemic stroke.