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Cover Journal of Neurosurgery

Middle meningeal artery embolization as standalone treatment versus combined with surgical evacuation for chronic subdural hematomas: systematic review and meta-analysis

Huanwen Chen, Marco Colasurdo, and Peter T. Kan

OBJECTIVE

Middle meningeal artery embolization (MMAE) is a novel treatment for chronic subdural hematomas (cSDHs) with high variability of use across practitioners and institutions. This study sought to investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgery for select patients with cSDH.

METHODS

The authors searched the Medline and Embase databases for studies reporting outcomes specific to standalone MMAE and combined MMAE and surgery. The Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool was used to assess risk of bias in each included study. Patient characteristics were compared between cohorts, and rates of surgical recurrence of standalone MMAE and combined MMAE and surgery were pooled using random-effects models.

RESULTS

Four hundred two unique patients (156 with standalone MMAE and 246 with combined MMAE and surgery) were identified across 8 studies. Overall, the subdural thickness for the standalone MMAE group was modestly but statistically significantly smaller (16.8 vs 18.8 mm, estimated p value 0.002), and the mean follow-up time was significantly longer for the standalone MMAE group (5.4 vs 2.3 months, estimated p value < 0.001); there were no significant differences between age, sex, and anticoagulant use. The surgical recurrence rates were not significantly different between the two groups (estimated p value 0.63). Using random-effects models, the surgical recurrence rates were estimated at 6.8% (95% CI 3.5%–11.2%) and 4.6% (95% CI 2.3%–7.7%) for standalone MMAE and combined MMAE and surgery, respectively.

CONCLUSIONS

Standalone MMAE for cSDH may yield a low rate of surgical recurrence, which may be comparable to that of combined MMAE and surgery. However, studies in this systematic review and meta-analysis were primarily single-arm studies prone to treatment bias. Future studies are needed to further investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgical treatment for cSDH in select patients.

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Cover Neurosurgical Focus

Conduits for cerebrovascular bypass and lessons learned from the cardiovascular experience

James K. Liu, Peter Kan, S. V. Karwande, and William T. Couldwell

Direct cerebral revascularization is an important procedure in the treatment of certain complex aneurysms and skull base tumors when acute sacrifice of the internal carotid artery is required. It likely remains an appropriate treatment in a small subgroup of patients with cerebral ischemia refractory to maximal medical management. Similar to cardiovascular surgery, the choice of a graft conduit is critical for a successful outcome. The standard conduits are interposition vein grafts (usually the greater saphenous vein), free arterial grafts (radial artery), and pedicled arterial grafts (superficial temporal artery). The goal of this review is to summarize the conduits commonly used in cerebral revascularization with emphasis on their patency rates and flow characteristics. Comparisons are made with similar data available in the cardiovascular literature.

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Cover Neurosurgical Focus

Simple closure following transsphenoidal surgery

Technical note

William T. Couldwell, Peter Kan, and Martin H. Weiss

✓ The most common nonendocrine complication after transsphenoidal surgery is cerebrospinal fluid (CSF) leak. Many neurosurgeons have advocated the routine reconstruction of the floor of the sella turcica using autologous fat, muscle, fascia, and either cartilage or bone after transsphenoidal surgery to prevent postoperative CSF fistulas. However, the use of autologous grafting requires a second incision, prolongs operative time, and adds to the patient's postoperative discomfort. In addition, the presence of sellar packing may interfere with the interpretation of postoperative images. To avoid these disadvantages, the authors suggest that routine sellar reconstruction or closure after transsphenoidal surgery is unnecessary unless an intraoperative CSF leak is encountered. The incidence of postoperative CSF leakage in the patients reported on in this series is no higher than that reported by others, and no other complications such as pneu-matocele have been encountered in approximately 2700 patients in whom no intraoperative CSF leak was encountered. The authors conclude that routine closure of the floor of the sella turcica or sphenoid is unnecessary in the absence of intraoperative CSF leak.

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Cover Journal of Neurosurgery: Pediatrics

Giant fusiform aneurysm in an adolescent with PHACES syndrome treated with a high-flow external carotid artery–M3 bypass

Case report and review of the literature

Peter Kan, James K. Liu, and William T. Couldwell

✓The acronym PHACES describes a rare neurocutaneous syndrome that comprises posterior fossa malformations, facial hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities, and sternal defects. Facial hemangiomas constitute the hallmark of this disorder. Giant intracranial aneurysms have not been previously reported in the literature as manifestations of PHACES syndrome and can present difficult therapeutic challenges. The authors describe a unique case of a 13-year-old adolescent boy with an incomplete phenotypic expression of PHACES syndrome who harbored diffuse cerebral angiodysplasia and a giant fusiform internal carotid artery (ICA) aneurysm extending from the distal cavernous segment to the supraclinoid segment. The aneurysm was successfully treated with a high-flow saphenous vein graft bypass from the external carotid artery to the distal middle cerebral artery followed by proximal ICA occlusion. This case represents a unique vascular manifestation of PHACES syndrome that required a complex management strategy. The authors review the literature on this rare disorder and emphasize the importance of considering the diagnosis of PHACES syndrome in child with a facial hemangioma.

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Cover Journal of Neurosurgery: Pediatrics

Endoscopic ultrasonic aspiration of an intraparenchymal hematoma in a newborn

Melissa A. LoPresti, Eric A. Goethe, James C. Bayley, Brandon Bertot, Peter T. Kan, and Sandi Lam

Neonatal intracerebral hemorrhage is associated with substantial morbidity and mortality. Treatment is largely conservative, though interventions to evacuate intraventricular and intraparenchymal hematomas (IPHs) have been applied. Endoscopic ultrasonic aspiration for the treatment of IPH has increasingly been shown to be a useful strategy in adults; however, it has not been studied in children, and the technology has been more commonly applied to intraventricular hemorrhage (IVH). Here, the authors describe, to the best of their knowledge, the first use of endoscopic ultrasonic aspiration for IPH in a newborn.

An 8-week-old female presented with IPH secondary to left M3 aneurysm rupture, which was treated with coil embolization for aneurysm securement and vessel sacrifice, followed by IPH evacuation using endoscopic ultrasonic aspiration. Through applying this approach in a newborn, the authors gained technical insight not previously reported in the application of this technique in similar cases in adults or in cases of IVH. They highlight this case to share learning points and technical challenges regarding the application of endoscopic ultrasonic aspiration in a newborn along with learning points for imaging and visualization. Endoscopic ultrasonic aspiration can be used to treat IPH in select newborns. Further study is needed to improve efficacy and ease when applying this approach in very young patients.

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Cover Neurosurgical Focus

Utility of CT perfusion scanning in patient selection for acute stroke intervention: experience at University at Buffalo Neurosurgery–Millard Fillmore Gates Circle Hospital

Peter T. Kan, Kenneth V. Snyder, Parham Yashar, Adnan H. Siddiqui, L. Nelson Hopkins, and Elad I. Levy

Computed tomography perfusion scanning generates physiological flow parameters of the brain parenchyma, allowing differentiation of ischemic penumbra and core infarct. Perfusion maps, along with the National Institutes of Health Stroke Scale score, are used as the bases for endovascular stroke intervention at the authors' institute, regardless of the time interval from stroke onset. With case examples, the authors illustrate their perfusion-based imaging guidelines in patient selection for endovascular treatment in the setting of acute stroke.

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Cover Journal of Neurosurgery

Harvey Cushing and Oskar Hirsch: early forefathers of modern transsphenoidal surgery

James K. LIU, Aaron A. Cohen-Gadol, Edward R. Laws Jr., Chad D. Cole, Peter Kan, and William T. Couldwell

✓ The transnasal transsphenoidal approach is the preferred route for removal of most lesions of the sella turcica. The concept of transnasal surgery traversing the sphenoid sinus to reach the sella has existed for nearly a century. A comprehensive historical overview of the evolution of transsphenoidal surgery has been reported previously. In the present vignette, the authors focus on transsphenoidal surgery in the early 1900s, particularly on the methods advocated by Harvey Cushing and Oskar Hirsch, two prominent pituitary surgeons who pioneered the transsphenoidal technique. Cushing championed the sublabial approach, whereas Hirsch was the master of the endonasal route. Coincidentally, both surgeons independently performed the submucous septal resection for the first time on June 4, 1910. Although Cushing's and Hirsch's approaches were predicated on the work of their predecessors, their transsphenoidal procedures became the two most popular techniques and, for future generations of pituitary surgeons, laid the foundation for modern transsphenoidal surgery. In this comparative analysis, the authors compare the operative nuances of the approaches of Cushing and Hirsch and describe the contributions of these pioneers to modern transsphenoidal surgery.

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Cover Journal of Neurosurgery

Decompression of cavernous sinus meningioma for preservation and improvement of cranial nerve function

Technical note

William T. Couldwell, Peter Kan, James K. Liu, and Ronald I. Apfelbaum

✓ Meningiomas are the most common tumors affecting the cavernous sinus (CS). Despite advances in microsurgery and radiosurgery, treatment of CS meningiomas remains difficult and controversial. As in cases of other meningiomas, the goal of treatment for CS meningioma is long-term growth control and preservation of neural function. Gross-total resection, the ideal treatment for meningioma, is not always possible to obtain in patients with CS meningiomas with an acceptable level of morbidity. Therefore, microsurgery and radiosurgery have recently been advocated as a combined therapy to achieve good control of tumor growth and favorable functional outcome. The authors describe a technique in which tumor volume can be reduced to a minimal residual amount, while preserving cranial nerve function. This enables the smallest field to be treated radiosurgically. The optic nerve is decompressed, and the tumor mass is reduced to provide at least a 5-mm interpositional distance between the optic nerve and the residual lesion. Direct decompression of the CS, with opening of the lateral and superior sinus walls, and piecemeal removal of the tumor in “safe” locations are performed to facilitate an improvement in cranial nerve function. The authors describe the use of this technique in a series of patients and demonstrate improvement of cranial nerve function in a subset of these patients.

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Cover Journal of Neurosurgery

Carotid artery–sparing repair of a cavernous carotid artery pseudoaneurysm

Case illustration

Peter Kan, Edwin A. Stevens, Richard R. Orlandi, and William T. Couldwell

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Cover Journal of Neurosurgery

Readmission following extracranial-intracranial bypass surgery in the United States: nationwide rates, causes, risk factors, and volume-driven outcomes

Kavelin Rumalla, Visish M. Srinivasan, Monica Gaddis, Peter Kan, Michael T. Lawton, and Jan-Karl Burkhardt

OBJECTIVE

Extracranial-intracranial (EC-IC) bypass surgery remains an important treatment option for patients with moyamoya disease (MMD), intracranial arteriosclerotic disease (ICAD) with symptomatic stenosis despite the best medical management, and complex aneurysms. The therapeutic benefit of cerebral bypass surgery depends on optimal patient selection and the minimization of periprocedural complications. The nationwide burden of readmissions and associated complications following EC-IC bypass surgery has not been previously described. Therefore, the authors sought to analyze a nationwide database to describe the national rates, causes, risk factors, complications, and morbidity associated with readmission following EC-IC bypass surgery for MMD, ICAD, and aneurysms.

METHODS

The Nationwide Readmissions Database (NRD) was queried for the years 2010–2014 to identify patients who had undergone EC-IC bypass for MMD, medically failed symptomatic ICAD, or unruptured aneurysms. Predictor variables included demographics, preexisting comorbidities, indication for surgery, and hospital bypass case volume. A high-volume center (HVC) was defined as one that performed 10 or more cases/year. Outcome variables included perioperative stroke, discharge disposition, length of stay, total hospital costs, and readmission (30 days, 90 days). Multivariable analysis was used to identify predictors of readmission and to study the effect of treatment at HVCs on quality outcomes.

RESULTS

In total, 2500 patients with a mean age of 41 years were treated with EC-IC bypass surgery for MMD (63.1%), ICAD (24.5%), or unruptured aneurysms (12.4%). The 30- and 90-day readmission rates were 7.5% and 14.0%, respectively. Causes of readmission included new stroke (2.5%), wound complications (2.5%), graft failure (1.5%), and other infection (1.3%). In the multivariable analysis, risk factors for readmission included Medicaid/self-pay (OR 1.6, 95% CI 1.1–2.4, vs private insurance), comorbidity score (OR 1.2, 95% CI 1.1–1.4, per additional comorbidity), and treatment at a non-HVC (OR 1.9, 95% CI 1.1–3.0). Treatment at an HVC (17% of patients) was associated with significantly lower rates of nonroutine discharge dispositions (13.4% vs 26.7%, p = 0.004), ischemic stroke within 90 days (0.8% vs 2.9%, p = 0.03), 30-day readmission (3.9% vs 8.2%, p = 0.03), and 90-day readmission (8.6% vs 15.2%, p = 0.01). These findings were confirmed in a multivariable analysis. The authors estimate that centralization to HVCs may result in 333 fewer nonroutine discharges (50% reduction), 12,000 fewer hospital days (44% reduction), 165 fewer readmissions (43%), and a cost savings of $15.3 million (11% reduction).

CONCLUSIONS

Readmission rates for patients after EC-IC bypass are comparable with those after other common cranial procedures and are primarily driven by preexisting comorbidities, socioeconomic status, and treatment at low-volume centers. Periprocedural complications, including stroke, graft failure, and wound complications, occurred at the expected rates, consistent with those in prior clinical series. The centralization of care may significantly reduce perioperative complications, readmissions, and hospital resource utilization.