Development of moyamoya arteriopathy following treatment of intracranial tumors: clinical and radiographic characterization.

OBJECTIVE: Moyamoya arteriopathy can develop in patients with brain tumors, particularly when associated with neurofibromatosis type 1 (NF1) or cranial irradiation. The present study aimed to analyze the clinical outcomes of moyamoya after brain tumor treatment and elucidate the effect of revascularization on brain tumors. METHODS: The authors retrospectively reviewed clinical and radiographic findings in 27 patients with brain tumors who developed moyamoya requiring revascularization surgery between January 1985 and June 2017 at a single institution. The long-term clinical and neuroimaging-based outcomes were analyzed. RESULTS: Among 27 patients, 22 patients underwent radiotherapy, and 12 patients had NF1. The mean ages at diagnosis of brain tumors and moyamoya were 4.4 years and 10.3 years, respectively. The mean interval between radiotherapy and moyamoya diagnosis was 4.0 years. The mean follow-up period after revascularization surgery was 8.5 years. Among 46 affected hemispheres in 27 patients, the patients who underwent radiotherapy (30 hemispheres in 22 patients) had a higher incidence of Suzuki stage 5 or 6 (20% [6/30] vs 0% [0/8]) and infarction (63.6% [14/22] vs 0% [0/5]) compared with patients without radiotherapy (8 hemispheres in 5 patients). After revascularization, stroke occurred in 4 patients, and 6 hemispheres showed Matsushima grade C, all of which occurred in patients with a history of radiotherapy. The residual brain tumors progressed in 4 of 21 patients (19%) after revascularization, comparable to the progression rates of brain tumors without revascularization in previous literature. CONCLUSIONS: Patients with brain tumors can develop moyamoya that exhibits characteristic clinical and radiographic features of idiopathic MMD. Moyamoya associated with cranial irradiation has a higher incidence of stroke with less capacity for revascularization, requiring thorough evaluations and timely treatment. Revascularization does not appear to have any effect on the progression of existing brain tumors.

First-Trimester Abortion Complications: Simulation Cases for OB/GYN Residents in Sepsis and Hemorrhage.

Introduction: Serious complications associated with first-trimester abortions are rare. The US mortality rate for these procedures is 0.7 per 100,000, primarily due to infection and hemorrhage. While complications are unlikely to arise during training, residents must be prepared to manage them in practice. To address this, we developed a 2-hour simulation-based abortion complication curriculum for OB/GYN resident learners. Methods: OB/GYN residents participated in three sessions: a case-based didactic reviewing institutional aspiration abortion practice and preop preparation; an in-vivo aspiration abortion hemorrhage simulation; and an interdepartmental postabortal sepsis simulation. Participants completed surveys before and after their participation that evaluated clinical knowledge, and self-rated competence in, and preparedness for, managing first-trimester abortion complications. Results: Resident learners (N = 26) represented all four classes of OB/GYN residents. Residents initially showed stronger clinical knowledge in managing postabortal hemorrhage than sepsis (90% vs. 62%, p < .001). Clinical knowledge improved following the sepsis simulation (62% to 91%, p < .001), and remained strong but unchanged after the hemorrhage simulation (90% to 87%, p = .3). Resident self-assessments of competence and preparedness were significantly improved after both the hemorrhage (p = .006) and sepsis (p = .002) simulations. Learners reported that the simulation increased their level of comfort in managing these complications in their future practice. Discussion: Postabortal hemorrhage and sepsis simulations increased OB/GYN residents' knowledge, comfort, and preparedness for managing rare complications of first-trimester abortions. In-vivo simulation and interdepartmental collaboration were novel aspects of these simulations that may facilitate increased preparedness and management skills.

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

OBJECTIVEThere 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.METHODSThis 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.RESULTSA 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.CONCLUSIONSRevascularization 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 5 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.

Moyamoya syndrome and PHACE syndrome: clinical and radiographic characterization of the intracranial arteriopathy and response to surgical revascularization.

OBJECTIVE: PHACE syndrome (PHACES) has been linked to cervical and cerebral vascular anomalies, including persistent embryonic anastomoses and progressive steno-occlusive disease. However, no prior studies have documented the long-term response of PHACES patients with moyamoya disease to surgical revascularization with pial or myosynangiosis. The authors present their experience with 8 consecutive patients with PHACES and moyamoya disease. METHODS: Retrospective review of patients who underwent pial synangiosis revascularization for moyamoya disease with concurrent diagnosis of PHACES. RESULTS: A total of 8 patients out of 456 surgically treated moyamoya patients had a diagnosis of PHACES. All patients were female, and their average age at the time of surgical treatment was 9.3 years (range 1.8-25.8 years). Five patients had associated basilar artery anomalies or stenosis. All patients had symptomatic narrowing of the petrous segment of the internal carotid artery with tortuous collateralization. Three patients underwent unilateral pial or myo-synangiosis and 5 underwent bilateral procedures. The average hospital length of stay was 5.0 days (range 3-7 days). There were no postoperative complications. Follow-up ranged from 8 to 160 months (average 56 months). Seven of 8 patients have had follow-up angiograms and all had Matsushima grade A or B collateralization without progression of stenosis in other locations. All patients had reduced cortical FLAIR signal on 6-month follow-up MRI and no evidence of new radiographic or clinical strokes. CONCLUSIONS: Patients with moyamoya disease and PHACES had an intracranial arteriopathy characterized by ectactic anterior vasculature with concomitant basilar artery stenosis, and were all female. The patients had both radiographic and clinical responses to pial synangiosis. The surgical treatment of these patients can be challenging given facial hemangiomas located near the surgical field. Patients with unilateral disease did not have evidence of progression in other cerebral circulation during the given follow-up period.

Imaging features and prognostic factors in fetal and postnatal torcular dural sinus malformations, part II: synthesis of the literature and patient management.

BACKGROUND: Torcular dural sinus malformations (tDSMs) are described as slow flow dural arteriovenous fistulae with frequently poor outcomes in the neuroangiographic literature, but other etiologies have been proposed in the obstetric literature, where outcomes have been more favorable. OBJECTIVE: To review tDSMs reported in the literature of multiple specialties for features that support a common etiology, and to identify key prognostic factors, with an emphasis on tDSM trajectory highlighted in part I. METHODS: Analysis of imaging features and clinical outcome for 77 prenatal and 22 postnatal tDSMs reported in 37 papers from the literature. RESULTS: In addition to large venous lakes, 36% of prenatal and 96% of postnatal tDSMs had evidence of arterialization, where specifically assessed. For fetal cases, where there was an observable natural history, 97% underwent a spontaneous decrease-13% after an initial increase and only 1 case with subsequent enlargement after a decrease. Prenatal cases had 83% survival (62% with a favorable outcome) whereas postnatal cases had 59% survival (29% favorable). In addition to a postnatal diagnosis, unfavorable features included ventriculomegaly, parenchymal injury, arterialization, and need for intervention. Favorable features included decreasing tDSM size, presence of clot, and increasing clot percentage. CONCLUSIONS: Neonatal and fetal tDSMs have overlapping imaging appearances, suggesting a common etiology, where neonatal tDSMs represent those rare fetal tDSMs that do not undergo spontaneous regression and have a propensity for worse outcomes. Decrease in tDSM size is a critical observation when managing a tDSM because it is generally irreversible and associated with a favorable outcome.

Imaging features and prognostic factors in fetal and postnatal torcular dural sinus malformations, part I: review of experience at Boston Children's Hospital.

BACKGROUND: Even for the most common dural sinus malformation (DSM), the torcular DSM (tDSM), generalizable statements about etiology and prognosis are difficult because neurosurgeons/neuroradiologists and obstetrical imagers have focused on different patient age groups, have reported different outcomes, and have offered differing pathophysiologic explanations. OBJECTIVE: To examine the imaging features and outcomes of a local cohort of tDSMs across fetal-neonatal life for commonalities. METHODS: Review of imaging and clinical outcome for a local cohort of 12 tDSM patients (9 fetal, 3 postnatal). RESULTS: All 12 tDSMs had similar imaging characteristics, including enlargement of the torcular and intraluminal thrombus early on, later evolving to peripheral scar tissue after treatment or spontaneous regression. Spontaneous decrease in size of the tDSM was observed in 6 prenatal and 1 postnatal case, and this decrease appeared to be irreversible once it occurred. One of 9 prenatal tDSMs was demonstrated to have arteriovenous fistulae in utero, while 2 of 3 postnatal diagnoses had arteriovenous fisutlae. All 6 prenatal tDSM diagnoses followed to term and all 3 postnatal diagnoses had a grossly normal neurologic outcome after a median of 12 months of age. CONCLUSIONS: Prenatal and postnatal tDSMs have overlapping imaging features suggesting a common etiology, and involution of a tDSM is a key imaging biomarker for a favorable outcome. While there is reason for concern with postnatally diagnosed tDSMs, good outcomes may still be achieved across the fetal-neonatal age spectrum of presentations. These findings are generalized in part II of this article.

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.

Preoperative transdural collateral vessels in moyamoya as radiographic biomarkers of disease.

OBJECTIVE The prevalence of angiographically evident preoperative transdural collateral vessels in moyamoya is not well documented. The authors hypothesized that transdural collaterals could be used as radiographic biomarkers of disease, and that their presence is associated with more advanced moyamoya arteriopathy at diagnosis, which is a harbinger of more frequent operative complications and a predictor of better long-term angiographic results following surgery. METHODS The study consists of a single-institution case series of patients with moyamoya who underwent pial synangiosis between 2005 and 2013. RESULTS Moyamoya was diagnosed in a total of 204 patients (n = 121 [59%] female, 83 [41%] male); the average age at surgery was 9.5 years (range 0.4-35 years). Radiographically, 154 (75%) had bilateral disease for a total of 308 affected hemispheres; 152 (75%) had radiographic stroke; and 190 (93%) had "ivy sign" on FLAIR MRI, indicating slow flow. Of the 358 hemispheres, 324 were treated operatively. On preoperative angiography, 107 patients (52%) had transdural collaterals in 176 affected hemispheres (49%). The Suzuki stage was higher in patients with collaterals (3.4 vs 3.0, p = 0.002). Of 324 treated hemispheres, 84 (26%) had collaterals within the surgical field. Complications included 12 strokes (3.7% stroke rate/hemisphere), with 5 (42%) directly attributable to interruption of transdural collaterals. On 1-year postoperative arteriograms available in 222 hemispheres, Matsushima grades trended better in patients with preoperative collaterals (1.5 vs 1.8 [A = 1, B = 2, C = 3]; p < 0.003). CONCLUSIONS Transdural collaterals are present in nearly half of all preoperative arteriograms in patients with moyamoya. These collaterals are more common in advanced disease, are associated with stroke as a perioperative complication, and may suggest increased capacity to produce surgical collaterals postoperatively. These data support the utility of preoperative arteriography.

Microsurgical treatment of arteriovenous malformations in pediatric patients: the Boston Children's Hospital experience.

OBJECT: Outcomes of microsurgical treatment of arteriovenous malformations (AVMs) in children are infrequently reported across large cohorts. METHODS: The authors undertook a retrospective review of departmental and hospital databases to obtain the medical data of all patients up to 18 years of age who were diagnosed with cerebral AVMs. Demographic and AVM angioarchitectural characteristics were analyzed, and for the patients who underwent surgery, the authors also analyzed the estimated intraoperative blood loss, postoperative angiographically confirmed obliteration rates, and neurological complications and outcomes classified according to the modified Rankin Scale (mRS). RESULTS: Of 117 children with cerebral AVMs, 94 underwent microsurgical resection (80%). Twenty (21%) of these 94 patients underwent adjunctive preoperative embolization. The overall postoperative angiographically confirmed obliteration rate was 94%. As part of a new protocol, the last 50 patients in this series underwent immediate perioperative angiography, improving the subsequent obliteration rate from 86% to 100% (p = 0.01). No other factors, such as a hemorrhagic AVM, size of the AVM, location, drainage, or Spetzler-Martin grade, had a statistically significant impact on the obliteration rate. Perioperative neurological deficits occurred in 17% of the patients, but the vast majority of these (77%) were predictable visual field cuts. Arteriovenous malformations that were hemorrhagic or located in noneloquent regions were each associated with lower rates of postoperative neurological complications (p = 0.05 and 0.002, respectively). In total, 94% of the children had good functional outcomes (mRS Scores 0-2), and these outcomes were significantly influenced by the mRS score on presentation before surgery (p = 0.01). A review of 1- and 5-year follow-up data indicated an overall annual hemorrhage rate of 0.3% and a recurrence rate of 0.9%. CONCLUSIONS: Microsurgical resection of AVMs in children is associated with high rates of angiographically confirmed obliteration and low rates of significant neurological complications. Implementation of a protocol using perioperative angiography in this series led to complete radiographically confirmed obliteration of all AVMs, with low annual repeat hemorrhage and recurrence rates.