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Patrick J. Codd, Alim P. Mitha and Christopher S. Ogilvy

Arteriovenous malformations are generally considered to be cured following angiographically proven complete resection. However, rare instances of AVM recurrence despite negative findings on postoperative angiography have been reported in both children and adults. In this paper, the authors present the case of a 33-year-old woman with 2 AVM recurrences. This patient represents the oldest case of recurrent AVM, and the first adult double recurrence reported in the literature. The case is presented, the radiological and surgical features are considered, and the literature on recurrent AVMs is reviewed.

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Alim P. Mitha, Erin E. Murphy and Christopher S. Ogilvy

✓ In this report, the authors present the case of a patient with a unique type of spinal arteriovenous fistula. Both the location and venous angioarchitecture of this variant are uncommon, making diagnosis of the lesion challenging and raising particular management issues. The authors discuss this unusual lesion and describe its imaging features and surgical findings, as well as highlight its pathological abnormalities.

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Alim P. Mitha, Kelly J. Bullivant, Julie L. Lauzon and Walter J. Hader

Macrocephaly-cutis marmorata telangiectatica congenita is a rare overgrowth syndrome commonly associated with hydrocephalus. Although the pathophysiological characteristics of the hydrocephalus in this syndrome is not fully known, previous reports have described its treatment with ventriculoperitoneal shunt placement. The authors describe 2 cases of macrocephaly-cutis marmorata telangiectatica congenita successfully treated for progressive hydrocephalus with endoscopic third ventriculostomy. Both patients experienced clinical and radiographic stabilization following treatment, and these findings offer insight into the pathophysiology of the hydrocephalus and its ideal management.

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Kelly J. Bullivant, Alim P. Mitha and Mark G. Hamilton

The PS Medical Strata valve is a programmable shunt valve used in the treatment of hydrocephalus that allows for noninvasive changes in the pressure setting using a magnet. The Strata valve is sensitive to magnetic fields, and reprogramming is frequently necessary after MR imaging. A known but rare complication of the Strata valve is that the rotor can become locked, causing shunt malfunction. This complication can only occur in a first generation Strata valve.

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Alim P. Mitha, John H. Wong, Michael D. Hill and Mayank Goyal

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Joshua P. Aronson, Alim P. Mitha, Brian L. Hoh, Pavan K. Auluck, Irina Pomerantseva, Joseph P. Vacanti and Christopher S. Ogilvy

Object

Recurrence after endovascular coiling of intracranial aneurysms is reported in up to 42% of cases and is attributed to the lack of endothelialization across the neck. In this study the authors used a novel tissue engineering approach to promote endothelialization by seeding endothelial progenitor cells (EPCs) within a fibrin polymer injected endovascularly into the aneurysm.

Methods

Experimental aneurysms were created in New Zealand White rabbits and were left untreated, surgically clipped, or embolized with platinum coils, fibrin biopolymer alone, or fibrin combined with autologous cultured EPCs.

Results

In aneurysms treated with EPCs, a confluent monolayer of endothelial cells with underlying neointima was demonstrated across the neck at 16 weeks posttreatment, which was not observed with aneurysms treated using the other methods.

Conclusions

This novel technique may address reasons for the limited durability of standard coil embolization and provides further avenues for the development of improved devices for the care of patients with aneurysms.

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Alim P. Mitha, Jay D. Turner, Adib A. Abla, A. Giancarlo Vishteh and Robert F. Spetzler

Object

The management of intramedullary spinal cord cavernous malformations (CMs) is controversial. At Barrow Neurological Institute, the authors selectively offer surgical treatment for symptomatic spinal cord CMs. The purpose of this paper is to review the clinical outcomes in patients after resection of these lesions based on a single-center experience over a 25-year period.

Methods

The records of 80 patients who underwent resection of pathologically confirmed spinal cord CMs from January 1985 to May 2010 were analyzed retrospectively. Preoperative clinical status and imaging findings were evaluated as well as immediate and long-term postoperative outcomes.

Results

Compared with their preoperative Frankel grade, 11% of patients were worse, 83% were the same, and 6% improved immediately after surgery. At a mean follow-up interval of 5 years, 10% of patients were worse, 68% were the same, and 23% were improved compared with their preoperative status. Five percent of patients underwent reoperation for resection of a symptomatic residual or recurrent lesion. Immediate complications were encountered in 6% of patients, including CSF leakage and deep venous thrombosis. Long-term complications were encountered in 14% of patients and included kyphotic deformity, stenosis, and spinal cord tethering. A significant correlation was found between long-term outcome and anteroposterior length of the lesion (p = 0.01).

Conclusions

The resection of intramedullary spinal cord CMs can be achieved with good long-term outcomes and an acceptable risk of immediate or delayed complications.

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Adib A. Abla, Jay D. Turner, Alim P. Mitha, Gregory Lekovic and Robert F. Spetzler

Brainstem cavernous malformations (CMs) are low-flow vascular lesions in eloquent locations. Their presentation is often marked with symptomatic hemorrhages that appear to occur more frequently than hemorrhage from supratentorial cavernomas. Brainstem CMs can be removed using 1 of the 5 standard skull-base approaches: retrosigmoid, suboccipital (with or without telovelar approach), supracerebellar infratentorial, orbitozygomatic, and far lateral.

Patients being referred to a tertiary institution often have lesions that are aggressive with respect to bleeding rates. Nonetheless, the indications for surgery, in the authors' opinion, are the same for all lesions: those that are symptomatic, those that cause mass effect, or those that abut a pial surface. Patients often have relapsing and remitting courses of symptoms, with each hemorrhage causing a progressive and stepwise decline. Many patients experience new postoperative deficits, most of which are transient and resolve fully. Despite the risks associated with operating in this highly eloquent tissue, most patients have had favorable outcomes in the authors' experience. Surgical treatment of brainstem CMs protects patients from the potentially devastating effects of rehemorrhage, and the authors believe that the benefits of intervention outweigh the risks in patients with the appropriate indications.

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Michael K. Tso, Myunghyun M. Lee, Chad G. Ball, William F. Morrish, Alim P. Mitha, Andrew W. Kirkpatrick and John H. Wong

OBJECTIVE

Blunt cerebrovascular injury (BCVI) occurs in approximately 1% of the blunt trauma population and may lead to stroke and death. Early vascular imaging in asymptomatic patients at high risk of having BCVI may lead to earlier diagnosis and possible stroke prevention. The objective of this study was to determine if the implementation of a formalized asymptomatic BCVI screening protocol with CT angiography (CTA) would lead to improved BCVI detection and stroke prevention.

METHODS

Patients with vascular imaging studies were identified from a prospective trauma registry at a single Level 1 trauma center between 2002 and 2008. Detection of BCVI and stroke rates were compared during the 3-year periods before and after implementation of a consensus-based asymptomatic BCVI screening protocol using CTA in 2005.

RESULTS

A total of 5480 patients with trauma were identified. The overall BCVI detection rate remained unchanged postprotocol compared with preprotocol (0.8% [24 of 3049 patients] vs 0.9% [23 of 2431 patients]; p = 0.53). However, postprotocol there was a trend toward a decreased risk of stroke secondary to BCVI on a trauma population basis (0.23% [7 of 3049 patients] vs 0.53% [13 of 2431 patients]; p = 0.06). Overall, 75% (35 of 47) of patients with BCVI were treated with antiplatelet agents, but no patient developed new or progressive intracranial hemorrhage despite 70% of these patients having concomitant traumatic brain injury.

CONCLUSIONS

The results of this study suggest that a CTA screening protocol for BCVI may be of clinical benefit with possible reduction in ischemic complications. The treatment of BCVI with antiplatelet agents appears to be safe.

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John H. Wong, Alim P. Mitha, Morgan Willson, Mark E. Hudon, Robert J. Sevick and Richard Frayne

Object

Digital subtraction (DS) angiography is the current gold standard of assessing intracranial aneurysms after coil placement. Magnetic resonance (MR) angiography offers a noninvasive, low-risk alternative, but its accuracy in delineating coil-treated aneurysms remains uncertain. The objective of this study, therefore, is to compare a high-resolution MR angiography protocol relative to DS angiography for the evaluation of coil-treated aneurysms.

Methods

In 2003, the authors initiated a prospective protocol of following up patients with coil-treated brain aneurysms using both 1.5-tesla gadolinium-enhanced MR angiography and biplanar DS angiography. Using acquired images, the subject aneurysm was independently scored for degree of remnant identified (complete obliteration, residual neck, or residual aneurysm) and the surgeon's ability to visualize the parent vessel (excellent, fair, or poor).

Results

Thirty-seven patients with 42 coil-treated aneurysms were enrolled for a total of 44 paired MR angiography–DS angiography tests (median 9 days between tests). An excellent correlation was found between DS and MR angiography for assessing any residual aneurysm, but not for visualizing the parent vessel (κ = 0.86 for residual aneurysm and 0.10 for parent vessel visualization). Paramagnetic artifact from the coil mass was minimal, and in some cases MR angiography identified contrast permeation into the coil mass not revealed by DS angiography. An intravascular microstent typically impeded proper visualization of the parent vessel on MR angiography.

Conclusions

Magnetic resonance angiography is a noninvasive and safe means of follow-up review for patients with coil-treated brain aneurysms. Compared with DS angiography, MR angiography accurately delineates residual aneurysm necks and parent vessel patency (in the absence of a stent), and offers superior visualization of contrast filling within the coil mass. Use of MR angiography may obviate the need for routine diagnostic DS angiography in select patients.