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Karam Moon, Andreas K. Filis and Alan R. Cohen

Mobile spinal tumors have been reported previously in the literature, with schwannomas as the most common form. A discrepancy between the location of the tumor in preoperative imaging and its actual position intraoperatively may lead to confusion. The authors present an unusual case of a mobile cauda equina ependymoma. Resection was complicated by cephalad migration of the tumor upon durotomy. Visualization was made possible by engaging a Valsalva maneuver in the patient under anesthesia, at which point the tumor was observed to migrate caudally into the operative field. Observation of this unique pathology is presented as potentially important knowledge for surgeons that might help prevent other unnecessary procedures such as a multilevel laminectomy.

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Bradley A. Gross, Felipe C. Albuquerque, Karam Moon and Cameron G. McDougall

OBJECTIVE

Many small series and technical reports chronicle the evolution of endovascular techniques for cranial dural arteriovenous fistulas (dAVFs) over the past 3 decades, but reports of large patient series are lacking. The authors provide a thorough analysis of clinical and angiographic outcomes across a large patient cohort.

METHODS

The authors reviewed their endovascular database from January 1996 to September 2015 to identify patients harboring cranial dAVFs who were treated initially with endovascular approaches. They extracted demographic, presentation, angiographic, detailed treatment, and long-term follow-up data, and they evaluated natural history, initial angiographic occlusion, complications, recurrence, and symptomatic resolution rates.

RESULTS

Across a cohort of 251 patients with 260 distinct dAVFs, the overall initial angiographic occlusion rate was 70%; recurrence or occult residual lesions were seen on subsequent angiography in 3% of cases. The overall complication rate was 8%, with permanent neurological complications occurring in 3% of cases. Among 102 patients with dAVFs without cortical venous reflux, rates of resolution/improvement of pulsatile tinnitus and ocular symptoms were 79% and 78%, respectively. Following the introduction of Onyx during the latter half of the study period, the number of treated dAVFs doubled; the initial angiographic occlusion rate increased significantly from 60% before the use of Onyx to 76% after (p = 0.01). In addition, during the latter period compared with the pre-Onyx period, the rate of dAVFs obliterated via a transarterial-only approach was significantly greater (43% vs 23%, p = 0.002), as was the number of dAVFs obliterated via a single arterial pedicle (29% vs 11%, p = 0.002).

CONCLUSIONS

Overall, in the Onyx era, the rate of initial angiographic occlusion was approximately 80%, as was the rate of meaningful clinical improvement in tinnitus and/or ocular symptoms after initial endovascular treatment of cranial dAVFs.

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Alfred P. See, Bruno C. Flores, Karam Moon, Andrew F. Ducruet, Robert F. Spetzler and Felipe C. Albuquerque

Supratentorial arteriovenous malformations in eloquent territories can be difficult to resect. This video presents the treatment of a patient with a symptomatic 3-cm arteriovenous malformation in the left motor strip. At the authors’ institution, per the surgeon’s discretion, preoperative angiography is performed to evaluate the need for preoperative embolization. Multimodality treatment reduced the microsurgical risk by allowing early occlusion of a draining vein, by decreasing overall intraoperative hemorrhage, and by allowing minimal pial dissection in the deep aspect of the arteriovenous malformation that abutted the corticospinal tract. The choice of embolysate was an additional nuance of the embolization.

The video can be found here: https://youtu.be/HWZ0RjgPEXg.

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Karam Moon, Felipe C. Albuquerque, Andrew F. Ducruet, R. Webster Crowley and Cameron G. McDougall

Object

Intracranial aneurysms, especially those of the cavernous segment of the internal carotid artery (ICA), can present with cranial nerve (CN) palsies. The Pipeline Embolization Device (PED) has demonstrated safety and efficacy in the treatment of cerebral aneurysms by flow diversion, but little data exist reporting the outcomes of cranial neuropathies following treatment with the device.

Methods

The prospectively maintained Barrow Neurological Institute's endovascular database was reviewed for all patients treated with the PED after presenting with one or more CN palsies secondary to a cerebral aneurysm since May 2011. Patient charts and digital subtraction angiograms were reviewed to report clinical and angiographic outcomes. Only patients with clinical follow-up were included in the analysis.

Results

A total of 127 patients were treated with the PED at the authors' institution after FDA approval. Twentytwo patients presented with cranial neuropathies, for initial inclusion in this study. Of these, 20 had sufficient followup for analysis. Cranial neuropathies included those of CN II, III, V, and VI, with presenting symptoms of diplopia, decreased visual acuity, and facial numbness and/or pain. Thirteen lesions were cavernous segment ICA aneurysms, whereas the remainder included supraclinoid and petrous segment ICA, posterior communicating artery, and basilar trunk aneurysms. At an average clinical follow-up of 9.55 months, 15 patients (75%) had resolution or significant improvement of their cranial neuropathies, and the remaining 5 had stable symptoms. Of the 18 patients with angiographic follow-up, 12 (66.7%) demonstrated complete obliteration or small neck residual, whereas 6 (33.3%) had residual lesion. Patients with complete or near-complete obliteration of their lesion were significantly more likely to demonstrate symptomatic improvement at follow-up (p = 0.009). Two patients with persistent symptoms were eventually treated with microsurgical bypass. Transient complications in this series included 6 (30%) extracranial hemorrhagic complications related to dual-antiplatelet therapy, all of which were managed medically. There was 1 delayed right ICA occlusion following retreatment that led to microsurgical bypass.

Conclusions

Intracranial aneurysms presenting with one or more CN palsies show a high rate of clinical improvement after treatment with the PED. Clinical outcomes must be weighed against the risks and challenges faced with flow diverters. Further research is warranted for patients whose symptoms do not respond optimally to device placement.

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Tsinsue Chen, Karam Moon, Daphne E. deMello, Iman Feiz-Erfan, Nicholas Theodore and Ratan D. Bhardwaj

A 13-year-old boy presented with fever and neck pain and stiffness, which was initially misdiagnosed as culture-negative meningitis. Magnetic resonance images of the brain and cervical spine demonstrated what appeared to be an intradural extramedullary mass at the C1–3 level, resulting in moderate cord compression, and a Chiari Type I malformation. The patient underwent a suboccipital craniectomy and a C1–3 laminectomy with intradural exploration for excisional biopsy and resection. The lesion containing the parasite was extradural, extending laterally through the C2–3 foramina. Inflammatory tissue secondary to Onchocerca lupi infection was identified, and treatment with steroids and doxycycline was initiated. At the 6-month follow-up, the patient remained asymptomatic, with MR images demonstrating a significant reduction in lesional size. However, 10 weeks postoperatively, the infection recurred, necessitating a second operation. The patient was treated with an additional course of doxycycline and is currently maintained on ivermectin therapy. This is the second reported case of cervical O. lupi infection in a human. In the authors' experience, oral doxycycline alone was insufficient in controlling the disease, and the addition of ivermectin therapy was necessary.

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Min S. Park, Michael Nanaszko, Matthew R. Sanborn, Karam Moon, Felipe C. Albuquerque and Cameron G. McDougall

OBJECT

The optimal strategy for use of the Pipeline Embolization Device (PED, ev3 Neurovascular) has not been clearly defined. The authors examined re-treatment rates after treatment with PED alone versus PED and adjunctive coil embolization (PED/coil).

METHODS

The authors retrospectively examined cerebral aneurysms treated with the PED from May 2011 to March 2014. Overall, 133 patients (25 men, 108 women; mean age 60.4 years, range 23–85 years) were treated for 140 aneurysms (mean size 11.8 ± 8.3 mm) requiring 224 PEDs (mean 1.7 PEDs per patient). Sixty-eight patients (13 men, 55 women) were treated with PED alone for 73 aneurysms (mean size 10.6 ± 9.2 mm) and 65 patients (12 men, 53 women) were treated with PED/coil for 67 aneurysms (mean size 12.8 ± 7.4 mm).

RESULTS

Eight aneurysms in 8 patients were re-treated in the PED-alone cohort versus only 1 aneurysm in 1 patient in the PED/coil cohort for re-treatment rates of 11.8% (8/68) and 1.5% (1/65), respectively (p = 0.03). Two patients in the PED-alone cohort were re-treated due to PED contraction, while the other 6 were re-treated for persistent filling of the aneurysms. The PED/coil patient experienced continued filling of a vertebrobasilar artery aneurysm. No aneurysms in either group ruptured after treatment.

CONCLUSIONS

Adjunctive coil embolization during flow diversion with the PED resulted in a significantly lower re-treatment rate compared with PED alone, suggesting an added benefit with adjunctive coil embolization. This result may provide the basis for future evaluation with randomized, controlled trials.

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Karam Moon, Andrew F. Ducruet, R. Webster Crowley, Kathleen Klas, Ruth Bristol and Felipe C. Albuquerque

In this paper the authors report the case of a complex dural arteriovenous fistula (dAVF) with high-risk features in a 14-year-old girl with Bannayan-Riley-Ruvalcaba syndrome (BRRS), a phosphatase and tensin homolog–associated syndrome, presenting with signs and symptoms of increased intracranial pressure (ICP) that had previously been attributed to pseudotumor cerebri. This fistula was obliterated following 2 stages of embolization, and the patient experienced immediate symptomatic improvement. At the 2-month follow-up evaluation, the fistula remained angiographically occluded, and her symptoms continue to improve. This is the third reported case of an intracranial dAVF in a patient with BRRS. Because high-risk dAVFs can result in devastating morbidity, early detection with vascular imaging is crucial for patients with BRRS presenting with signs of increased ICP. Goals of treatment should include complete fistula obliteration whenever possible.

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Michael R. Levitt, Randall J. Hlubek, Karam Moon, M. Yashar S. Kalani, Peter Nakaji, Kris A. Smith, Andrew S. Little, Kerry Knievel, Jane W. Chan, Cameron G. McDougall and Felipe C. Albuquerque

OBJECTIVE

Cerebral venous pressure gradient (CVPG) from dural venous sinus stenosis is implicated in headache syndromes such as idiopathic intracranial hypertension (IIH). The incidence of CVPG in headache patients has not been reported.

METHODS

The authors reviewed all cerebral venograms with manometry performed for headache between January 2008 and May 2015. Patient demographics, headache etiology, intracranial pressure (ICP) measurements, and radiographic and manometric results were recorded. CVPG was defined as a difference ≥ 8 mm Hg by venographic manometry.

RESULTS

One hundred sixty-four venograms were performed in 155 patients. There were no procedural complications. Ninety-six procedures (58.5%) were for patients with IIH. The overall incidence of CVPG was 25.6% (42 of 164 procedures): 35.4% (34 of 96 procedures) in IIH patients and 11.8% (8 of 68 procedures) in non-IIH patients. Sixty procedures (36.6%) were performed in patients with preexisting shunts. Seventy-seven patients (49.7%) had procedures preceded by an ICP measurement within 4 weeks of venography, and in 66 (85.7%) of these patients, the ICP had been found to be elevated. CVPG was seen in 8.3% (n = 5) of the procedures in the 60 patients with a preexisting shunt and in 0% (n = 0) of the 11 procedures in the 77 patients with normal ICP (p < 0.001 for both). Noninvasive imaging (MR venography, CT venography) was assessed prior to venography in 112 (68.3%) of 164 cases, and dural venous sinus abnormalities were demonstrated in 73 (65.2%) of these cases; there was a trend toward CVPG (p = 0.07). Multivariate analysis demonstrated an increased likelihood of CVPG in patients with IIH (OR 4.97, 95% CI 1.71–14.47) and a decreased likelihood in patients with a preexisting shunt (OR 0.09, 95% CI 0.02–0.44).

CONCLUSIONS

CVPG is uncommon in IIH patients, rare in those with preexisting shunts, and absent in those with normal ICP.

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Al-Wala Awad, Karam Moon, Nam Yoon, Marcus D. Mazur, M. Yashar S. Kalani, Philipp Taussky, Cameron G. McDougall, Felipe C. Albuquerque and Min S. Park

OBJECTIVE

Flow diversion has proven to be an efficacious means of treating cerebral aneurysms that are refractory to other therapeutic means. Patients with tandem aneurysms treated with flow diversion have been included in larger, previously reported series; however, there are no dedicated reports on using this technique during a single session to treat this unique subset of patients. Therefore, the authors analyzed the outcomes of patients who had undergone single-session flow diversion for the treatment of tandem aneurysms.

METHODS

The authors conducted a retrospective review of flow diversion with the Pipeline embolization device (PED) for the treatment of tandem aneurysms in a single session at 2 participating medical centers: University of Utah, Salt Lake City, Utah, and Barrow Neurological Institute, Phoenix, Arizona. Patient demographic data, aneurysm characteristics, treatment strategy and results, complications, and follow-up data were collected from the medical record and analyzed.

RESULTS

Between January 2011 and December 2015, 17 patients (12 female, 5 male) with a total of 38 aneurysms (mean size 4.7 ± 2.7 mm, mean ± SD) were treated. Sixteen patients had aneurysms in the anterior circulation, and 1 patient had tandem aneurysms in the posterior circulation. Twelve patients underwent only placement of a PED, whereas 5 underwent adjunctive coil embolization of at least 1 aneurysm. One PED was used in each of 9 patients, and 2 PEDs were required in each of 8 patients. There were 2 intraprocedural complications; however, in both instances, the patients were asymptomatic at the last follow-up. The follow-up imaging studies were available for 15 patients at a mean of 7 months after treatment (216 days, range 0–540 days). The mean initial Raymond score after treatment was 2.7 ± 0.7, and the mean final score was 1.3 ± 0.7.

CONCLUSIONS

In this series, the use of flow diversion for the treatment of tandem cerebral aneurysms had an acceptable safety profile, indicating that it should be considered as an effective therapy for this complicated subset of patients. Further prospective studies must be performed before more definitive conclusions can be made.