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Daniel M. S. Raper, Nasser Mohammed, M. Yashar S. Kalani, and Min S. Park

The preferred method for treating complex dural arteriovenous fistulae of the transverse and sigmoid sinuses is via endovascular, transarterial embolization using liquid embolysate. However, this treatment approach mandates access to distal dural feeding arteries that can be technically challenging by standard endovascular approaches. This video describes a left temporal craniotomy for direct stick microcatheterization of an endovascularly inaccessible distal posterior division of the middle meningeal artery for embolization of a complex left temporal dural arteriovenous fistula. The case was performed in the hybrid operative suite with biplane intraoperative angiography. Technical considerations, operative nuances, and outcomes are reviewed.

The video can be found here: https://youtu.be/Dnd4yHgaKcQ.

Open access

Daniel M. S. Raper, Kunal P. Raygor, Caleb Rutledge, Todd B. Dubnicoff, and Adib A. Abla

Posterior fossa arteriovenous malformations (AVMs) in pregnant patients can present unique considerations for surgical treatment, including positioning to minimize pressure on the fetus, minimization of radiation exposure, and ethical considerations regarding emergency surgery. This video outlines surgical treatment of a ruptured tonsillar/vermian AVM performed in a staged fashion after emergent suboccipital craniotomy with posterior fossa decompression in the setting of a life-threatening infratentorial hemorrhage. Later, bilateral cerebellomedullary fissure dissection, exposure and dissection of the tela choroidea and inferior medullary velum, and disconnection of arterial feeders from the posterior inferior cerebellar artery (PICA) allowed resection of this AVM occupying the roof of the fourth ventricle.

This study was approved by the UCSF Human Research Protection Program IRB no. 18-26938.

The video can be found here: https://youtu.be/rTYUGanopUE

Open access

Huy Dang, Patrick Cotton, Tyler Lazaro, A. Basit Khan, Alex N. Hoang, Omar Tanweer, and Daniel M. S. Raper

BACKGROUND

PulseRider is an endovascular device that can be a useful adjunctive device for wide-necked bifurcation aneurysms. However, its use in distal vessels such as the anterior cerebral artery (ACA) has not been widely reported.

OBSERVATIONS

The authors reported the case of a 75-year-old woman who underwent coiling of a 6.9-mm distal ACA aneurysm with PulseRider assistance. Using a partially intraaneurysmal deployment technique, the wide-necked aneurysm was successfully embolized, resulting in Raymond-Roy class II occlusion without intra- or periprocedural complications.

LESSONS

This case illustrates a novel approach to treatment for wide-necked distal ACA aneurysms, which can be challenging to treat via traditional endovascular means. PulseRider can be safely used to treat distal ACA aneurysms with minimal residual aneurysm.

Full access

Ashish H. Shah, Karthik Madhavan, Deborah Heros, Daniel M. S. Raper, J. Bryan Iorgulescu, Brian E. Lally, and Ricardo J. Komotar

Object

The discovery of incidental low-grade gliomas (LGGs) on MR imaging is rare, and currently there is no existing protocol for management of these lesions. Various studies have approached the dilemma of managing patients with incidental LGGs. While some advocate surgery and radiotherapy, others reserve surgery until there is radiological evidence of growth. For neurosurgeons and radiologists, determining the course of action after routine brain imaging poses not only a medical but also an ethical dilemma. The authors conducted a systematic review of case reports and case series in hopes of enhancing the current understanding of the management options for these rare lesions.

Methods

A PubMed search was performed to include all relevant MR imaging studies in which management of suspected incidental LGG was reported. Comparisons were made between the surgical treatment arm and the active surveillance arm in terms of outcome, mode of discovery, reasons for treatment, and histology.

Results

Nine studies with 72 patients were included in this study (56 in the surgical arm and 16 in the active surveillance arm). Within the surgical arm, 49% remained deficit free after treatment, 25% showed evidence of tumor progression, 13% underwent a second treatment, and 7% died. The active surveillance group resulted in no unanticipated adverse events, with serial imaging revealing no tumor growth in all cases. Lesion regression was reported in 31% of this group. The surgical arm's mortality rate was 7% compared with 0% in the active surveillance arm.

Conclusions

Treatment decisions for incidental LGG should be individualized based on presenting symptoms and radiological evidence of growth. The asymptomatic patient may be monitored safely with serial MR imaging and occasionally PET scanning before treatment is initiated. In patients presenting with nonspecific symptoms or concurrent symptomatic lesions, treatment may be initiated earlier to reduce potential morbidity. All treatment decisions must be tempered by patient factors and expectations of anticipated benefit.

Restricted access

Ricardo J. Komotar, Daniel M. S. Raper, Robert M. Starke, J. Bryan Iorgulescu, and Philip H. Gutin

Object

Meningiomas are one of the more common intracranial neoplasms. The risk of seizures and secondary aspiration, brain edema, and brain injury often leads practitioners to administer prophylactic antiepileptic drugs (AEDs) perioperatively. The efficacy of this practice remains controversial, however, with prior investigations reaching conflicting results and recent studies focusing on AED side effects. The authors performed a systematic analysis of outcomes following supratentorial meningioma resection with and without prophylactic AED administration in the hope of clarifying the role of AEDs in the perioperative care of patients with these lesions.

Methods

A MEDLINE search of the literature (1979–2010) was performed. Comparisons were made for patient and tumor characteristics as well as success of repair, morbidity, and seizure outcome. Statistical analyses of categorical variables were undertaken using chi-square and Fisher exact tests.

Results

Nineteen studies, involving 698 patients, were included. There were no significant differences in the extent of resection, perioperative mortality, or recurrence between the AED and no-AED cohorts. Likewise, there were no significant differences in the incidence of early or late seizures between the cohorts.

Conclusions

The results of this systematic analysis supports the conclusion that the prophylactic administration of anticonvulsants during resection of supratentorial meningiomas provides no benefit in the prevention of either early or late postoperative seizures. Despite their traditional role in this patient population, the routine use of AEDs should be carefully reconsidered.

Restricted access

Kunal S. Patel, Ricardo J. Komotar, Oszkar Szentirmai, Nelson Moussazadeh, Daniel M. Raper, Robert M. Starke, Vijay K. Anand, and Theodore H. Schwartz

Object

Endoscopic transsphenoidal surgery is expanding in acceptance, yet postoperative CSF leak rates remain a concern. This study presents the Cornell closure protocol, which has yielded significantly lower postoperative CSF leak rates compared with prior reports, as an algorithm that can be used by centers having difficulty with CSF leak.

Methods

A single closure algorithm for endoscopic surgery has been used since January 2010 at Weill Cornell Medical College. A prospective database noting intraoperative CSF leak, closure technique, and postoperative CSF leak was reviewed. The authors used a MEDLINE search to identify similar studies and compared CSF leak rates to those of patients treated using the Cornell algorithm.

Results

The retrospective study of a prospectively acquired database included 209 consecutive patients. In 84 patients (40%) there was no intraoperative CSF leak and no postoperative CSF leak. In the 125 patients (60%) with an intraoperative CSF leak, 35 of them with high-flow leaks, there were 0 (0%) postoperative CSF leaks.

Conclusions

It is possible to achieve a CSF leak rate of 0% by using this closure protocol. With proper experience, endoscopic skull base surgery should not be considered to have a higher CSF leak rate than open transcranial or microscopic transsphenoidal surgery.

Free access

Vijay Letchuman, Leonel Ampie, Panagiotis Mastorakos, Daniel M. S. Raper, Ryan T. Kellogg, and Min S. Park

Moyamoya disease is a rare disorder of the cerebrovascular system affecting individuals in a bimodal age distribution and is characterized by progressive vascular stenosis of the bilateral supraclinoid internal carotid arteries with compensatory formation of collateral vessels at the base of the brain. Despite the disease’s initial description in the literature in 1957, little progress has been made in the development of medical and surgical therapeutics due to, in no small part, the lack of effective experimental animal models. Currently, there is a poor understanding of the pathophysiological mechanisms behind the development of the moyamoya vasculopathies. Since the description of a genetic association between moyamoya disease, few studies have investigated the impact of genetic manipulation on the development of an animal model for experimentation. To date, no one model recapitulates the precise phenotype of the moyamoya vasculopathies, although development of an appropriate model would allow for an in-depth investigation into the pathological mechanisms underlying the disease. In this review, the authors discuss the immunological, mechanical, and genetic methods used to develop moyamoya experimental models, as well as future perspectives.

Open access

Zachary K. Christian, Alex N. Hoang, Huy Dang, Abdul B. Khan, Daniel M. S. Raper, Zachary S. Pallister, and Omar Tanweer

BACKGROUND

Patients with symptomatic high-grade stenosis of the internal carotid artery (ICA) associated with a free-floating thrombus (FFT) present a significant clinical challenge. In general, for patients with moderate to severe symptomatic ICA stenosis, carotid revascularization is recommended within 2 weeks of symptom onset; however, some physicians suggest that revascularization should be delayed in cases with FFT because some data suggest that early surgery with carotid endarterectomy or carotid stent poses a higher risk for stroke. Likewise, delayed revascularization with anticoagulation may increase risk of recurrent stroke. Few reports on the management of FTT included the use of a transcarotid artery revascularization (TCAR) approach for carotid revascularization with mechanical aspiration thrombectomy.

OBSERVATIONS

This report described the use of TCAR for direct mechanical thrombectomy and carotid stent placement for a patient with 80% right ICA stenosis along with a large FFT extending into the bulb and the external carotid artery.

LESSONS

The TCAR approach for mechanical thrombectomy and carotid stenting is a safe alternative for early revascularization with low periprocedural stroke risks.

Full access

Thomas J. Buell, Daniel M. S. Raper, I. Jonathan Pomeraniec, Dale Ding, Ching-Jen Chen, Davis G. Taylor, and Kenneth C. Liu

Stenosis of the transverse sinus (TS) and sigmoid sinus (SS), with a trans-stenosis pressure gradient, has been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH). MRI has shown improvement in TS and SS stenosis after high-volume lumbar puncture (HVLP) in a subset of patients with IIH. The authors present the first report of an IIH patient with immediate post-HVLP TS and SS trans-stenosis pressure gradient reduction and an attendant increase in TS and SS cross-sectional area confirmed using intravascular ultrasonography (IVUS). Recurrence of the patient’s TS-SS stenosis coincided with elevated HVLP opening pressure, and venous sinus stent placement resulted in clinical improvement. This report suggests that TS and SS stenosis may be a downstream effect of elevated intracranial pressure in IIH, rather than its principal etiological mechanism. However, the authors hypothesize that endovascular stenting may obliterate a positive feedback loop involving trans-stenosis pressure gradients, and still benefit appropriately selected patients.

Restricted access

Ricardo J. Komotar, J. Bryan Iorgulescu, Daniel M. S. Raper, Eric C. Holland, Kathryn Beal, Mark H. Bilsky, Cameron W. Brennan, Viviane Tabar, Jonathan H. Sherman, Yoshiya Yamada, and Philip H. Gutin

Object

Atypical (WHO Grade II) meningiomas comprise a heterogeneous group of tumors, with histopathology delineated under the guidance of the WHO and a spectrum of clinical outcomes. The role of postoperative radiotherapy for patients with atypical meningiomas who have undergone gross-total resection (GTR) remains unclear. In this paper, the authors sought to clarify this role by reviewing their experience over the past 2 decades.

Methods

The authors retrospectively analyzed all patients at their institution who underwent GTR between 1992 and 2011 with a final histology demonstrating atypical meningioma. Information regarding patients, tumor characteristics, and postoperative adjuvant therapy was gleaned from medical records. Time to recurrence and overall survival were analyzed using univariate, multivariate, and Kaplan-Meier survival analyses.

Results

Forty-five patients who met the inclusion criteria underwent GTR for atypical meningiomas. By a median follow-up of 44.1 months, 22% of atypical meningiomas had recurred. There was no recurrence in 12 (92%) of 13 patients who received postoperative radiotherapy or in 19 (59%) of 32 patients who did not undergo postoperative radiotherapy (p = 0.085), demonstrating a strong trend toward improved local control with postoperative radiotherapy. No other factors were significantly associated with recurrence in univariate or multivariate analyses.

Conclusions

This retrospective series supports the observation that postoperative radiotherapy likely results in lower recurrence rates of gross totally resected atypical meningiomas. Although a multicenter prospective trial will ultimately be needed to fully define the role of radiotherapy in managing gross totally resected atypical meningiomas, the authors' results contribute to a growing number of series that support routine postoperative radiotherapy as an adjuvant treatment for these lesions.