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Joon K. Song, Aman B. Patel, Gary R. Duckwiler, Y. Pierre Gobin, Reza Jahan, Neil A. Martin, Edwin D. Cacayorin and Fernando Viñuela

✓ The authors present the case of a 69-year-old man who suffered from bilateral cortical venous hypertension due to a brain pial arteriovenous malformation (AVM) with a high-flow fistula. The AVM became complicated by the development of a high-grade stenosis of the posterior superior sagittal sinus (SSS). A comparison of cerebral angiograms obtained at different times revealed that the severe SSS stenosis had developed within a 5-year period and was located distal to the nidus of the left parietal AVM nidus, away from the entrance of the dominant superior superficial cortical draining vein into the SSS. The high-flow fistula was occluded with detachable coils and the AVM nidus was further embolized with acrylic. The SSS stenosis was mechanically dilated by means of balloon angioplasty and stent placement. This case provides angiographic evidence to support the hypothesis that a pial arteriovenous fistula in an adult can cause high-flow occlusive venopathy in a major sinus within a relatively short time and that this acquired high-flow occlusive venopathy can develop at an atypical location distant from the nidus of the AVM.

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Chirag D. Gandhi, Ronit Gilad, Aman B. Patel, Abilash Haridas and Joshua B. Bederson

Object

Lenticulostriate artery (LSA) aneurysms are rarely reported in the literature, making management decisions challenging. Conservative, endovascular, and surgical treatments have been described primarily through case reports and reports of individual authors' experiences. The purpose of this study is to report neurological outcomes in a single-institution experience of ruptured lenticulostriate aneurysms treated surgically.

Methods

The authors have conducted a retrospective review of all cases involving patients with ruptured LSA aneurysms who presented to the Mt. Sinai Hospital neurosurgical service between September 2001 and January 2007.

Results

Over 5.4 years, the authors treated 6 patients with 7 LSA aneurysms—6 ruptured and 1 unruptured. The Hunt and Hess grade on admission ranged from I to IV, with subarachnoid hemorrhage in 5 of the 6 patients. Catheter angiography confirmed the presence of the aneurysms, and all patients underwent a pterional craniotomy and clipping or resection of the aneurysm, performed by a single surgeon.

Associated risk factors in our series of patients included hypertension, cocaine abuse, and intracranial occlusive disease suggestive of moyamoya disease. Two types of LSA aneurysms were identified. The mean size of the 6 ruptured aneurysms was 3.2 mm. The LSA was preserved in 3 of 6 patients, but LSA preservation did not correlate with development of a postoperative infarct, clinically or radiologically. In patients with ruptured aneurysms, the mean modified Rankin Scale score at discharge was 1.7. The 3 patients in whom the LSA was sacrificed had good outcomes, suggesting that loss of the artery is clinically well tolerated.

Conclusions

This case series demonstrates that surgical treatment of ruptured LSA aneurysms can be an appropriate, effective, and safe therapy.

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Oral Presentations

2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010

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Christoph J. Griessenauer, Christopher S. Ogilvy, Paul M. Foreman, Michelle H. Chua, Mark R. Harrigan, Christopher J. Stapleton, Aman B. Patel, Lucy He, Matthew R. Fusco, J Mocco, Peter A. Winkler, Apar S. Patel and Ajith J. Thomas

OBJECTIVE

Contemporary treatment for paraophthalmic artery aneurysms includes flow diversion utilizing the Pipeline Embolization Device (PED). Little is known, however, about the potential implications of the anatomical relationship of the ophthalmic artery (OA) origin and aneurysm, especially in smaller aneurysms.

METHODS

Four major academic institutions in the United States provided data on small paraophthalmic aneurysms (≤ 7 mm) that were treated with PED between 2009 and 2015. The anatomical relationship of OA origin and aneurysm, radiographic outcomes of aneurysm occlusion, and patency of the OA were assessed using digital subtraction angiography. OA origin was classified as follows: Type 1, OA separate from the aneurysm; Type 2, OA from the aneurysm neck; and Type 3, OA from the aneurysm dome. Clinical outcome was assessed using the modified Rankin Scale, and visual deficits were categorized as transient or permanent.

RESULTS

The cumulative number of small paraophthalmic aneurysms treated with PED between 2009 and 2015 at the 4 participating institutions was 69 in 52 patients (54.1 ± 13.7 years of age) with a male-to-female ratio of 1:12. The distribution of OA origin was 72.5% for Type 1, 17.4% for Type 2, and 10.1% for Type 3. Radiographic outcome at the last follow-up (median 11.5 months) was available for 54 aneurysms (78.3%) with complete, near-complete, and incomplete occlusion rates of 81.5%, 5.6%, and 12.9%, respectively. Two aneurysms (3%) resulted in transient visual deficits, and no patient experienced a permanent visual deficit. At the last follow-up, the OA was patent in 96.8% of treated aneurysms. Type 3 OA origin was associated with a lower rate of complete aneurysm occlusion (p = 0.0297), demonstrating a trend toward visual deficits (p = 0.0797) and a lower rate of OA patency (p = 0.0783).

CONCLUSIONS

Pipeline embolization treatment of small paraophthalmic aneurysms is safe and effective. An aneurysm where the OA arises from the aneurysm dome may be associated with lower rates of aneurysm occlusion, OA patency, and higher rates of transient visual deficits.

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Matthew J. Koch, Christopher J. Stapleton, Pankaj K. Agarwalla, Collin Torok, John H. Shin, Jean-Valery Coumans, Lawrence F. Borges, Christopher S. Ogilvy, James D. Rabinov and Aman B. Patel

OBJECTIVE

Vascular malformations of the spine represent rare clinical entities with profound neurological implications. Previously reported studies on management strategies for spinal dural arteriovenous fistulas (sDAVFs) appeared before the advent of modern liquid embolic agents. Authors of the present study review their institutional experience with endovascularly and surgically treated sDAVFs.

METHODS

The authors performed a retrospective, observational, single-center case series on sDAVFs treated with endovascular embolization, microsurgical occlusion, or both between 2004 and 2013. The mode, efficacy, and clinical effect of treatment were evaluated.

RESULTS

Forty-seven patients with spinal arteriovenous malformations were evaluated using spinal angiography, which demonstrated 34 Type I sDAVFs (thoracic 20, lumbar 12, and cervical 2). Twenty-nine of the patients (85%) were male, and the median patient age was 63.3 years. Twenty patients underwent primary endovascular embolization (16 Onyx, 4 N-butyl cyanoacrylate [NBCA]), and 14 underwent primary surgical clipping. At a mean follow-up of 36 weeks, according to angiography or MR angiography, 5 patients treated with endovascular embolization demonstrated persistent arteriovenous shunting, whereas none of the surgically treated patients showed lesion persistence (p = 0.0237). Thirty patients (88%) experienced some resolution of their presenting symptoms (embolization 17 [85%], surgery 13 [93%], p = 1.00).

CONCLUSIONS

Microsurgical occlusion remains the most definitive treatment modality for sDAVFs, though modern endovascular techniques remain a viable option for the initial treatment of anatomically amenable lesions. Treatment of these lesions usually results in some clinical improvement.

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Christopher J. Stapleton, Thabele M. Leslie-Mazwi, Collin M. Torok, Reza Hakimelahi, Joshua A. Hirsch, Albert J. Yoo, James D. Rabinov and Aman B. Patel

OBJECTIVE

Endovascular thrombectomy in patients with acute ischemic stroke caused by occlusion of the proximal anterior circulation arteries is superior to standard medical therapy. Stentriever thrombectomy with or without aspiration assistance was the predominant technique used in the 5 randomized controlled trials that demonstrated the superiority of endovascular thrombectomy. Other studies have highlighted the efficacy of a direct aspiration first-pass technique (ADAPT).

METHODS

To compare the angiographic and clinical outcomes of ADAPT versus stentriever thrombectomy in patients with emergent large vessel occlusions (ELVO) of the anterior intracranial circulation, the records of 134 patients who were treated between June 2012 and October 2015 were reviewed.

RESULTS

Within this cohort, 117 patients were eligible for evaluation. ADAPT was used in 47 patients, 20 (42.5%) of whom required rescue stentriever thrombectomy, and primary stentriever thrombectomy was performed in 70 patients. Patients in the ADAPT group were slightly younger than those in the stentriever group (63.5 vs 69.4 years; p = 0.04); however, there were no differences in the other baseline clinical or radiographic factors. Procedural time (54.0 vs 77.1 minutes; p < 0.01) and time to a Thrombolysis in Cerebral Infarction (TICI) scale score of 2b/3 recanalization (294.3 vs 346.7 minutes; p < 0.01) were significantly lower in patients undergoing ADAPT versus stentriever thrombectomy. The rates of TICI 2b/3 recanalization were similar between the ADAPT and stentriever groups (82.9% vs 71.4%; p = 0.19). There were no differences in the rates of symptomatic intracranial hemorrhage or procedural complications. The rates of good functional outcome (modified Rankin Scale Score 0–2) at 90 days were similar between the ADAPT and stentriever groups (48.9% vs 41.4%; p = 0.45), even when accounting for the subset of patients in the ADAPT group who required rescue stentriever thrombectomy.

CONCLUSIONS

The present study demonstrates that ADAPT and primary stentriever thrombectomy for acute ischemic stroke due to ELVO are equivalent with respect to the rates of TICI 2b/3 recanalization and 90-day mRS scores. Given the reduced procedural time and time to TICI 2b/3 recanalization with similar functional outcomes, an initial attempt at recanalization with ADAPT may be warranted prior to stentriever thrombectomy.

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Rahul A. Sastry, Matthew J. Koch, Benjamin L. Grannan, Christopher J. Stapleton, William E. Butler and Aman B. Patel

Endoscopic third ventriculostomy (ETV) is a common treatment for noncommunicating hydrocephalus. Although rare, vascular injury and traumatic pseudoaneurysm development during ETV have been reported. The authors present the case of a 13-year-old boy who underwent repeat ETV (rETV) for shunt and ETV failure, and who suffered an intraoperative subarachnoid hemorrhage due to iatrogenic injury to the basilar tip, with subsequent development of a pseudoaneurysm. Despite initial primary coil embolization, the aneurysm recurred and was definitively treated with flow diversion. In this report, the authors review complication rates associated with ETV and rETV as well as the emerging use of flow diversion and its applications in vessel reconstruction within the pediatric population.

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Tomoaki Suzuki, Christopher J. Stapleton, Matthew J. Koch, Kazutoshi Tanaka, Soichiro Fujimura, Takashi Suzuki, Takeshi Yanagisawa, Makoto Yamamoto, Yukihiko Fujii, Yuichi Murayama and Aman B. Patel

OBJECTIVE

Degenerative cerebral aneurysm walls are associated with aneurysm rupture and subarachnoid hemorrhage. Thin-walled regions (TWRs) represent fragile areas that may eventually lead to aneurysm rupture. Previous computational fluid dynamics (CFD) studies reported the correlation of maximum pressure (Pmax) areas and TWRs; however, the correlation with aneurysm rupture has not been established. This study aims to investigate this hemodynamic correlation.

METHODS

The aneurysmal wall surface at the Pmax areas was intraoperatively evaluated using a fluid flow formula under pulsatile blood flow conditions in 23 patients with 23 saccular middle cerebral artery (MCA) bifurcation aneurysms (16 unruptured and 7 ruptured). The pressure difference (Pd) at the Pmax areas was calculated by subtracting the average pressure (Pave) from the Pmax and normalized by dividing this by the dynamic pressure at the aneurysm inlet side. The wall shear stress (WSS) was also calculated at the Pmax areas, aneurysm dome, and parent artery. These hemodynamic parameters were used to validate the correlation with TWRs in unruptured MCA aneurysms. The characteristic hemodynamic parameters at the rupture points in ruptured MCA aneurysms were then determined.

RESULTS

In 13 of 16 unruptured aneurysms (81.2%), Pmax areas were identified that corresponded to TWRs. In 5 of the 7 ruptured cerebral aneurysms, the Pmax areas coincided with the rupture point. At these areas, the Pd values were not higher than those of the TWRs in unruptured cerebral aneurysms; however, minimum WSS, time-averaged WSS, and normalized WSS at the rupture point were significantly lower than those of the TWRs in unruptured aneurysms (p < 0.01).

CONCLUSIONS

At the Pmax area of TWRs, decreased WSS appears to be the crucial hemodynamic parameter that indicates the risk of aneurysm rupture.