Cerebral revascularization using gracilis muscle transplantation for childhood moyamoya disease

Surgical revascularization of frontal areas in pediatric Moyamoya vasculopathy: a systematic review

INTRODUCTION

The aim of this study is to systematically review the literature on surgical revascularization techniques for flow-augmentation of the frontal areas and/or anterior cerebral artery (ACA) territory in children with Moyamoya vasculopathy (MMV), to elucidate the current surgical practice and describe the outcome associated to the different techniques.

EVIDENCE ACQUISITION

The systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. MEDLINE, Web of Science and EMBASE were searched up to April 2020. Published techniques were systematically analyzed according to level of evidence, revascularization technique, opening of the interhemispheric fissure (IF), uni- or bilateral revascularization, clinical, neurocognitive, angiographic, perfusion and hemodynamic outcome.

EVIDENCE SYNTHESIS

Twenty-five studies were enrolled, including 829 patients: among these, 13 patients underwent direct revascularization of ACA territories, 570 indirect revascularization and 246 patients combined revascularization. One study reached a level of evidence II (grade of recommendation B), 8 studies were level III (grade B) and 16 studies were level IV (grade C). The surgical techniques proposed in the enrolled papers were systematically described.

CONCLUSIONS

Combined techniques (grade of recommendation B) and indirect techniques (grade of recommendation C) are considered effective for revascularizing the frontal areas and/or anterior cerebral artery (ACA) territory in children with MMV. While performing the revascularization, surgical risks can be reduced by avoiding the exposure of the superior sagittal sinus and opening of IF (recommendation grade C). There is not sufficient evidence to define which type of surgical technique should be preferred. Future studies are needed for a longitudinal assessment of comparable outcomes and to determine which revascularization technique for the frontal areas and/or ACA territory is optimal for this highly specific pediatric population.

Sibling cases of moyamoya disease having homozygous and heterozygous c.14576G>A variant in RNF213 showed varying clinical course and severity

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive occlusion of the terminal portion of the internal carotid arteries and their branches. A genetic background was under speculation, because of the high incidence of familial occurrence. Sibling cases usually exhibit a similar clinical course. Recently, RNF213 was identified as the first MMD susceptibility gene. The c.14576G>A variant of RNF213 significantly increases the MMD risk, with an odds ratio of 190.8. Furthermore, there is a strong association between clinical phenotype and the dosage of this variant. The present study described sibling MMD cases having homozygous and heterozygous c.14576G>A variant in RNF213, as well as different clinical course and disease severity. The homozygote of c.14576G>A variant showed an early onset age and rapid disease progress, which resulted in significant neurological deficits with severe and wide distribution of vasculopathy. In contrast, the heterozygote of the variant showed a relatively late-onset age and mild clinical course without irreversible brain lesions with limited distribution of vasculopathy. This is the first report of sibling MMD cases with different doses of the RNF213 variant, showing its genetic impact on clinical phenotype even in members with similar genetic background.

Indirect revascularization techniques for treating moyamoya disease

There have been many indirect revascularization techniques described by surgeons for the treatment of moyamoya disease. These surgical procedures are typically used more commonly in pediatric, than in adults', cases. Some of the techniques include: cervical sympathectomy, omental transplantation, multiple burr holes, encephalo-myo-synangiosis (EMS), encephalo-arterio-synangiosis (EAS), encephalo-duro-synangiosis (EDS), encephalo-myo-arterio-synangiosis (EMAS), encephalo-duro-arterio-synangiosis (EDAS), encephalo-duro-arterio-myo-synangiosis (EDAMS), encephalo-duro-galeo (periosteal)-synangiosis (EDGS), and combinations of all the above. This chapter will detail the technical aspects of many of these procedures and some of the reported clinical outcomes.

Subcutaneous tissue graft including a scalp artery and a relevant vein for the treatment of cerebral ischemia in childhood moyamoya disease

BACKGROUND

Simple indirect anastomosis was introduced for the treatment of moyamoya disease with cerebral ischemia in the territory of anterior cerebral arteries (ACAs) or middle cerebral arteries (MCAs), and its clinical usefulness was discussed.

METHODS

The study included 19 patients with childhood moyamoya disease who were operated on with subcutaneous tissue graft including a scalp artery and a relevant vein (group 1). They all had repetitive transient ischemic attacks (TIAs) in the territory of ACAs or MCAs. To compare age, sex, and the time required for the operation, 34 patients with childhood moyamoya disease with direct anastomosis were also included in the (group 2).

RESULTS

No TIAs were observed in 19 of 21 operative sides during the follow-up period in group 1. The remaining 2 sides continued to have TIAs postsurgically, but with a marked decrease in frequency. There were no significant differences in age and sex between group 1 and group 2. Required time for surgical procedure in group 1 ranged from 103 to 270 minutes (mean +/- SD, 167.4 +/- 38.8 minutes), and in group 2 from 140 to 320 minutes (215.0 +/- 36.2 minutes). The former was significantly shorter than the latter (unpaired t test, t = 4.8773, P = .000007).

CONCLUSIONS

Subcutaneous tissue graft including a scalp artery and a relevant vein is recommended for the treatment of moyamoya disease presenting ischemia in the territory of the ACAs or MCAs.

Revascularisation surgery for paediatric moyamoya: a review of the literature

INTRODUCTION AND AIMS

The role of and optimal surgical revascularisation technique for paediatric moyamoya syndrome (MMS) are controversial. In this literature review our primary aim was to evaluate the evidence base for the efficacy of surgical revascularisation for the treatment of paediatric MMS. Secondary aims were to estimate the rate of peri-operative complications and to ascertain whether direct or indirect revascularisation techniques resulted in differences in clinical or radiological outcomes.

METHODS

Papers describing surgical revascularisation and its outcome in the treatment of children with MMS were identified from the OVID Medline database (1966-2004). Only papers in English were reviewed. Data were abstracted using a standardised form.

RESULTS

Fifty-seven studies, including data on 1,448 patients, were reviewed. Most were Japanese; 10% were from Western institutions. Indications for revascularisation were described in <15% of studies and varied between centres. Indirect procedures were most commonly performed (alone in 73% of cases, combined with direct procedures in 23%). The rates of peri-operative stroke and reversible ischaemic events were 4.4 and 6.1% respectively. Out of 1,156 (87%) patients, 1,003 derived symptomatic benefit from surgical revascularisation (complete disappearance or reduction in symptomatic cerebral ischaemia), with no significant difference between the indirect and direct/combined groups. Data on developmental and functional outcomes were limited and of uncertain significance as they were not related to pre-operative status. Good collateral formation was significantly more frequent in the direct/combined group than in the indirect group (chi(2), p<0.001).

CONCLUSIONS

Data from the medical literature suggest that surgical revascularisation is a safe intervention for paediatric MMS and most treated patients derive some symptomatic benefit. However, paucity of data on selection criteria and more global outcome measures means that the impact of surgical revascularisation on natural history remains uncertain. Direct and/or combined procedures provide better revascularisation, but this is not associated with differences in symptomatic outcome. International standardisation of the clinical approach to the treatment of paediatric MMS is urgently needed to critically evaluate the optimal indications for and timing of surgical revascularisation.

Patch angioplasty to repair the arteriotomy defect in the wall of the middle cerebral artery after failure of superficial temporal artery-middle cerebral artery anastomosis in moyamoya disease--case report

A 65-year-old woman presented with moyamoya disease associated with a saccular aneurysm of the posterior cerebral artery. The surgical plan required superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis to be conducted before neck clipping of the aneurysm to provide collateral flow via the STA to prevent ischemia if temporary occlusion of the parent artery of the aneurysm was needed. However, the anastomotic procedure failed because the STA was occluded at the site of temporary clip application. End-to-end anastomosis of the STA was planned after excising the occluded site of the STA, but end-to-end anastomosis could not be performed because the donor artery was too short for anastomosis to the branch of the MCA. Therefore, patch grafting using a piece of wall of the STA was performed to repair the arteriotomy defect in the wall of the MCA, followed by neck clipping of the saccular aneurysm in the posterior circulation via the subtemporal approach. Vascular reconstruction can be recommended if arterial anastomosis between a superficial skin artery and a branch of the MCA is impossible due to an intraoperative accident or technical difficulty and reperfusion is necessary.

Cerebral revascularization using omentum and muscle free flap for ischemic cerebrovascular disease

BACKGROUND

Indirect cerebral revascularization has been generally accepted in the management of brain ischemia in moyamoya disease. We performed indirect cerebral revascularization by using omental flap and muscle flap techniques for the treatment of ischemic cerebrovascular disease.

METHODS

Ten patients with ischemic cerebrovascular disease including three with adult moyamoya disease underwent this procedure (omental flap on eight sides and muscle flap on five sides). The muscle used for the flap was the serratus anterior muscle on two sides and shaved latissimus dorsi muscle on three sides. Angiography and cerebral blood flow studies were performed in all patients preoperatively and postoperatively. All patients demonstrated severely impaired cerebrovascular reserve capacity due to occlusive disease.

RESULTS

There was one patient each with perioperative death and intracranial infection following omental flap loss, and two patients had perioperative strokes. The average follow-up period was 23.2 months. Of the nine surviving patients, all eight except for the one with flap loss had good outcome with complete resolution of neurologic episodes.

CONCLUSIONS

It is concluded that this method seems to be effective in selected patients with ischemic cerebrovascular disease.

Risk factors for neurologic deterioration after revascularization surgery in patients with moyamoya disease

To investigate the risk factors for postoperative neurological deterioration in patients with moyamoya disease, we retrospectively reviewed the perioperative course of 368 cases of revascularization surgery in 216 patients with this disease. Risk factors anecdotally associated with postoperative ischemic events were analyzed by comparing groups with or without a history of such events on the operative day. Ischemic events were noted in 14 cases (3.8%), 4 of which were defined as strokes and the others as transient ischemic attack (TIA). Postoperative neurological deterioration more often developed in patients who suffered from frequent TIAs, had precipitating factors for TIA, and underwent indirect nonanastomotic revascularization. The authors conclude that the incidence of postoperative ischemic events were related more to the severity of moyamoya disease and the type of surgical procedure than to other factors, including anesthetic management.

IMPLICATIONS

Although preventing stroke is the major concern for patients with moyamoya disease, risk factors for perioperative cerebral ischemia have not been clarified. We retrospectively analyzed the perioperative course in 368 cases with this disease and found that the severity of the disease and type of surgical procedure were major determinants of postoperative cerebral ischemia.

Natural history of moyamoya disease: comparison of activity of daily living in surgery and non surgery groups

The present study was undertaken to reach a clearer understanding of the natural history of Moyamoya disease. Follow-up studies were performed in 88 patients with Moyamoya disease. They were divided into the ischemia group and the hemorrhage group. The activity of daily living (ADL) of each groups were followed up and compared between those who were surgically treated and conservatively managed. Ischemic manifestations were more common in the younger children and tended to be recurrent, whereas hemorrhagic manifestations were more common in the adults. Follow-up duration of the 36 patients, who were surgically treated, ranged from 6 to 86.4 months (mean: 28.8 months). During the follow-up period, ADL was improved in 17 of 31 ischemic Moyamoya patients (55%); the condition was unchanged in nine (29%); and aggravated in five (16%). Follow-up duration of the 52 patients who were managed without surgery ranged from 12 to 216 months (mean: 67.2 months). In 35 patients of the ischemia group, ADL was aggravated in 49% and improved in only 26% during the follow-up period. However, ADL was aggravated in 12% of 17 hemorrhagic patients, but improved in 53%. Our result suggest that indirect revascularization procedures are effective for prevention of recurrent ischemic attacks which is common in pediatric patients. However, the effectiveness of indirect revascularization for hemorrhagic Moyamoya disease is not clear and requires extended follow-up study.

Preoperative and postoperative evaluation of cerebral perfusion and vasodilatory capacity with 99mTc-HMPAO SPECT and acetazolamide in childhood Moyamoya disease

BACKGROUND AND PURPOSE

The results of long-term follow-up studies of cerebral perfusion and vasodilatory capacity following administration of acetazolamide after serial vascular reconstructions in 25 patients with childhood moyamoya disease are reported.

METHODS

Cerebral perfusion was measured with 99mTc-hexamethylpropyleneamine oxime single-photon emission CT before and after IV administration of 10 mg/kg acetazolamide, which was performed both before and after vascular reconstruction by superficial temporal artery-middle cerebral artery anastomosis and encephalomyosynangiosis (first and second operations) and/or omental transplantation to the brain (third operation).

RESULTS

Follow-up periods ranged between 12 and 24 months (mean +/- SD, 18.5 +/- 3.2 months) after the first operation. Repetitive transient ischemic attacks disappeared completely after serial vascular reconstructions in all patients. Before the first operation, cerebral perfusion in the territory of the middle cerebral artery on the side of initial operation was 83.9 +/- 4.7% and was significantly lower than that in the contralateral side (88.3 +/- 4.9%, n = 25; P < .0001, paired t test). Vasodilatory capacity on the side of the first operation was -18.4 +/- 2.5% and that on the contralateral side -14.4 +/- 2.1%. The former value was significantly lower than the latter value (n = 25; P < .0001, paired t test). After the first operation, cerebral perfusion and vasodilatory capacity on the side of initial operation were markedly improved, to 87.8 +/- 4.5% and -14.7 +/- 2.7%, respectively (n = 25; P < .0001, both cases, paired t test). Before the second operation, cerebral perfusion and vasodilatory capacity on the side of the second operation were 76.6 +/- 4.1% and -20.1 +/- 1.9%, respectively, and significantly lower than those before the first operation (n = 25; P < .0001, both cases, paired t test). Eight patients subsequently required bifrontal omental transplantation for repetitive paraparetic transient ischemic attacks after the second operation; they had low cerebral perfusion and vasodilatory capacity bilaterally in the territories of the anterior cerebral arteries (72.4 +/- 2.7% and -18.6 +/- 1.7%, respectively). After omental transplantation, both were significantly increased, to 81.9 +/- 3.4% and -11.8 +/- 1.9%, respectively (n = 25; P < .0001, both cases, paired t test).

CONCLUSIONS

Hemodynamic compromise existed in patients with childhood moyamoya disease and was a major cause of development of ischemic symptoms. Regions in which hemodynamic compromise was present could be determined by measuring regional cerebral perfusion and vasodilatory capacity.