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Christopher Carr, Lora Kahn, Mansour Mathkour, Erin Biro, Cuong J. Bui and Aaron S. Dumont

OBJECTIVE

The Global Burden of Disease (GBD) is an international collaboration and the largest comprehensive investigation of global health disease burden ever conducted. It has been particularly insightful for understanding disease demographics in middle-income nations undergoing rapid development, such as Vietnam, where 6 of the top 10 causes of death are relevant to the neurosurgeon. The burden of stroke—the number one cause of death in Vietnam—is particularly impressive. Likewise, road injuries, with a disproportionate rate of traumatic brain injury, continue to increase in Vietnam following economic development. Low-back and neck pain is the number one cause of disability. Simultaneously, more patients have access to care, and healthcare spending is increased.

METHODS

It is imperative that neurosurgical capital and infrastructure keep pace with Vietnam’s growth. The authors searched the existing literature for assessments of neurosurgical infrastructure or initiatives to address neurosurgical disease burden. Using GBD data, the authors also abstracted data for death by cause and prevalence of years of life lost due to disability (YLD) for common neurosurgical pathologies for Vietnam and comparison nations.

RESULTS

Interventions aimed at primary prevention of risk factors for neurosurgical disease and focused on the transference of self-sustainable technical skills were found to be analogous to those that have been successful in other regions. Efforts toward stroke prevention have been focused on causal risk factors. Multiple investigators have found that interventions aimed at increasing helmet use were successful in preventing traumatic brain injury. Government-led reforms and equipment donation programs have improved technical capacity. Nevertheless, Vietnam lags behind other nations in neurosurgeons per capita; cause-attributable death and YLD attributable to neurosurgical disease are considerably higher in Vietnam and middle-income nations compared to both lower-income nations and upper-income nations.

CONCLUSIONS

More than two-thirds of deaths attributable to neurosurgical pathologies in Vietnam and other middle-income nations were due to stroke, and one-fifth of both cause-attributable death and YLD was associated with neurosurgical pathologies. Vietnam and other middle-income nations continue to assume a global burden of disease profile that ever more closely resembles that of developed nations, with particular cerebrovascular, neurotrauma, and spinal disease burdens, leading to exponentially increased demand for neurosurgeons that threatens to outpace the training of neurosurgeons.

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Peter S. Amenta, Ricky Medel and Aaron S. Dumont

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Nohra Chalouhi, Cory D. Bovenzi, Vismay Thakkar, Jeremy Dressler, Pascal Jabbour, Robert M. Starke, Sonia Teufack, L. Fernando Gonzalez, Richard Dalyai, Aaron S. Dumont, Robert Rosenwasser and Stavropoula Tjoumakaris

Object

Aneurysm recurrence after coil therapy remains a major shortcoming in the endovascular management of cerebral aneurysms. The need for long-term imaging follow-up was recently investigated. This study assessed the diagnostic yield of long-term digital subtraction angiography (DSA) follow-up and determined predictors of delayed aneurysm recurrence and retreatment.

Methods

Inclusion criteria were as follows: 1) available short-term and long-term (> 36 months) follow-up DSA images, and 2) no or only minor aneurysm recurrence (not requiring further intervention, i.e., < 20%) documented on short-term follow-up DSA images.

Results

Of 209 patients included in the study, 88 (42%) presented with subarachnoid hemorrhage. On shortterm follow-up DSA images, 158 (75%) aneurysms showed no recurrence, and 51 (25%) showed minor recurrence (< 20%, not retreated). On long-term follow-up DSA images, 124 (59%) aneurysms showed no recurrence, and 85 (41%) aneurysms showed recurrence, of which 55 (26%) required retreatment. In multivariate analysis, the predictors of recurrence on long-term follow-up DSA images were as follows: 1) larger aneurysm size (p = 0.001), 2) male sex (p = 0.006), 3) conventional coil therapy (p = 0.05), 4) aneurysm location (p = 0.01), and 5) a minor recurrence on short-term follow-up DSA images (p = 0.007). Ruptured aneurysm status was not a predictive factor. The sensitivity of short-term follow-up DSA studies was only 40.0% for detecting delayed aneurysm recurrence and 45.5% for detecting delayed recurrence requiring further treatment.

Conclusions

The results of this study highlight the importance of long-term angiographic follow-up after coil therapy for ruptured and unruptured intracranial aneurysms. Predictors of delayed recurrence and retreatment include large aneurysms, recurrence on short-term follow-up DSA images (even minor), male sex, and conventional coil therapy.

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Stephen J. Monteith, Asterios Tsimpas, Aaron S. Dumont, Stavropoula Tjoumakaris, L. Fernando Gonzalez, Robert H. Rosenwasser and Pascal Jabbour

Object

Despite advances in surgical and endovascular techniques, fusiform aneurysms remain a therapeutic challenge. Introduction of flow-diverting stents has revolutionized the treatment of aneurysms with wide necks and of complex morphology. The authors report their experience with the endovascular treatment of fusiform aneurysms using the Pipeline Embolization Device.

Methods

A retrospective review of 146 patients with cerebral aneurysms treated with the Pipeline Embolization Device between June 2011 and January 2013 was performed. Twenty-four patients were identified as having fusiform aneurysms. Twenty-four aneurysms in these 24 patients were treated. The mean patient age was 59 years. There were 9 men and 15 women. Angiographic and clinical data (including the modified Rankin Scale [mRS] score) were recorded at the time of treatment and at follow-up. The aneurysms were located in the internal carotid artery in 8 patients (33.3%), middle cerebral artery in 8 patients (33.3%), anterior cerebral artery in 1 patient (4%), and vertebrobasilar circulation in 7 patients (29%). The aneurysms were smaller than 10 mm in 3 patients, 10–25 mm in 16 patients, and larger than 25 mm in 5 patients. The mean largest dimension diameter was 18 mm.

Results

Stent deployment was successful in all cases. The minor procedural morbidity was 4% (1 case). Morbidity and mortality related to aneurysm treatment were 4.2% and 4.2%, respectively. The mean mRS scores preoperatively and at clinical follow-up (median 6.0 months, mean 6.9 months) were 0.71 and 1.2, respectively (91.7% presented with an mRS score of 2 or better, and 79.2% had an mRS score of 2 or better at the 6.0-month follow-up). At clinical follow-up, 82.6% of patients were stable or had improved, 13.0% worsened, and 4.2% had died. Twenty-two (91.7%) of 24 patients had follow-up angiography available (mean follow-up time 6.3 months); 59% had excellent angiographic results (> 95% or complete occlusion), 31.8% had complete aneurysm occlusion, 27.3% had greater than 95% aneurysm occlusion, 18.2% had a moderate decrease in size (50%–95%), 4.5% had a minimal decrease in size (< 50%), 13.6% had not changed, and 4.5% had an increase in size.

Conclusions

This series demonstrates that endovascular treatment of fusiform cerebral aneurysms with flow diversion was a safe and effective treatment. Procedural complications were low. Long-term morbidity and mortality rates were acceptable given the complex nature of these lesions.

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Ana Rodríguez-Hernández, Ahmed J. Awad and Michael T. Lawton

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Edward H. Oldfield, Johanna J. Loomba, Stephen J. Monteith, R. Webster Crowley, Ricky Medel, Daryl R. Gress, Neal F. Kassell, Aaron S. Dumont and Craig Sherman

Object

Intravenous sodium nitrite has been shown to prevent and reverse cerebral vasospasm in a primate model of subarachnoid hemorrhage (SAH). The present Phase IIA dose-escalation study of sodium nitrite was conducted to determine the compound's safety in humans with aneurysmal SAH and to establish its pharmacokinetics during a 14-day infusion.

Methods

In 18 patients (3 cohorts of 6 patients each) with SAH from a ruptured cerebral aneurysm, nitrite (3 patients) or saline (3 patients) was infused. Sodium nitrite and saline were delivered intravenously for 14 days, and a dose-escalation scheme was used for the nitrite, with a maximum dose of 64 nmol/kg/min. Sodium nitrite blood levels were frequently sampled and measured using mass spectroscopy, and blood methemoglobin levels were continuously monitored using a pulse oximeter.

Results

In the 14-day infusions in critically ill patients with SAH, there was no toxicity or systemic hypotension, and blood methemoglobin levels remained at 3.3% or less in all patients. Nitrite levels increased rapidly during intravenous infusion and reached steady-state levels by 12 hours after the start of infusion on Day 1. The nitrite plasma half-life was less than 1 hour across all dose levels evaluated after stopping nitrite infusions on Day 14.

Conclusions

Previous preclinical investigations of sodium nitrite for the prevention and reversal of vasospasm in a primate model of SAH were effective using doses similar to the highest dose examined in the current study (64 nmol/kg/min). Results of the current study suggest that safe and potentially therapeutic levels of nitrite can be achieved and sustained in critically ill patients after SAH from a ruptured cerebral aneurysm. Clinical trial registration no.: NCT00873015 (ClinicalTrials.gov).

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Nohra Chalouhi, Pascal Jabbour, Robert M. Starke, Stavropoula I. Tjoumakaris, L. Fernando Gonzalez, Samantha Witte, Robert H. Rosenwasser and Aaron S. Dumont

Object

Surgical clipping of posterior inferior cerebellar artery (PICA) aneurysms can be challenging and carries a potentially significant risk of morbidity and mortality. Experience with endovascular therapy has been limited to a few studies. The authors assess the feasibility, safety, and efficacy of endovascular therapy in the largest series of proximal and distal PICA aneurysms to date.

Methods

A total of 76 patients, 54 with proximal and 22 with distal PICA aneurysms, underwent endovascular treatment at Jefferson Hospital for Neuroscience between 2001 and 2011.

Results

Endovascular treatment was successful in 52 patients (96.3%) with proximal aneurysms and 19 patients (86.4%) with distal aneurysms. Treatment consisted of selective aneurysm coiling in 60 patients (84.5%) (including 4 with stent assistance and 4 with balloon assistance) and parent vessel trapping in 11 patients (15.5%). Specifically, a deconstructive procedure was necessary in 9.6% of proximal aneurysms (5 of 52) and 31.6% of distal aneurysms (6 of 19). There were 9 overall procedural complications (12.7%), 6 infarcts (8.5%; 4 occurring after deliberate occlusion of the PICA), and 3 intraprocedural ruptures (4.2%). The rate of procedure-related permanent morbidity was 2.8%. Complete aneurysm occlusion was achieved in 63.4% of patients (45 of 71). One patient (1.4%) treated with selective aneurysm coiling suffered a rehemorrhage on postoperative Day 15. The mean angiographic follow-up time was 17.2 months. Recurrence and re-treatment rates were, respectively, 20% and 17.1% for proximal aneurysms compared with 30.8% and 23.1% for distal aneurysms. Favorable outcomes (moderate, mild, or no disability) at follow-up were seen in 93% of patients with unruptured aneurysms and in 78.7% of those with ruptured aneurysms.

Conclusions

Endovascular therapy is a feasible, safe, and effective treatment in patients with proximal and distal PICA aneurysms, providing excellent patient outcomes and adequate protection against rehemorrhage. The long-term incidence of aneurysm recanalization appears to be high, especially in distal aneurysms, and requires careful angiographic follow-up.

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Pascal Jabbour, Nohra Chalouhi, Stavropoula Tjoumakaris, L. Fernando Gonzalez, Aaron S. Dumont, Rohan Chitale, Robert Rosenwasser, Carlos G. Bianciotto and Carol Shields

Retinoblastoma is a deadly eye cancer in children, leading to death in 50%–70% of children in undeveloped nations who are diagnosed with it. This malignancy is the most common intraocular tumor in childhood worldwide. The good prognosis in developed nations is related to early detection and advanced treatments. With the advent of intraarterial chemotherapy, neurosurgeons have taken a central role in the treatment of this pediatric condition. Intraarterial chemotherapy is a novel treatment for retinoblastoma whereby chemotherapeutic agents are precisely delivered into the ophthalmic artery, minimizing systemic toxicity. This procedure has shown impressive results and has allowed a dramatic decrease in the rate of enucleation (eye removal) in advanced and refractory retinoblastoma. Recent reports have raised some concerns about the risk of ocular vasculopathy, radiation-related toxicity, and the potential for metastatic disease after intraarterial chemotherapy. In the authors' experience of more than 3 years, tumor control is excellent with globe salvage at 67% and vascular events less than 5%, mostly related to improvement in technique. The role of this novel approach in the management of retinoblastoma has yet to be defined. As more centers are adopting the technique, the topic will decidedly become the focus of intensive future research. In this paper, the authors review and discuss current data regarding intraarterial chemotherapy for retinoblastoma.

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Nohra Chalouhi, Aaron S. Dumont, Stavropoula Tjoumakaris, L. Fernando Gonzalez, Jurij R. Bilyk, Ciro Randazzo, David Hasan, Richard T. Dalyai, Robert Rosenwasser and Pascal Jabbour

Object

Endovascular therapy is the primary treatment option for carotid-cavernous fistulas (CCFs). Operative cannulation of the superior ophthalmic vein (SOV) provides a reasonable alternative route to the cavernous sinus when all transvenous and transarterial approaches have been unsuccessful. The role of the liquid embolic agent Onyx in the management of CCFs has not been well documented, especially when using an SOV approach. The purpose of this study is to assess the safety and efficacy of Onyx embolization of CCFs through a surgical cannulation of the SOV.

Methods

The authors retrospectively reviewed all patients with CCFs who were treated with Onyx through an SOV approach between April 2009 and April 2011. Traditional endovascular approaches had failed in all patients.

Results

A total of 10 patients were identified, 1 with a Type A CCF, 5 with a Type B CCF, and 4 with a Type D CCF. All fistulas were embolized in 1 session. Onyx was the sole embolic agent used in 7 cases and was combined with coils in 3 other cases. Complete obliteration was achieved in 8 patients and a significant reduction in fistulous flow was achieved in 2 patients, which later progressed to near-complete occlusion on angiographic follow-up. All patients experienced a complete clinical recovery with excellent cosmetic results and were free from recurrence at their latest clinical follow-up evaluations.

Conclusions

Onyx embolization is an excellent therapy for CCFs in general, and through an SOV approach in particular. Direct operative cannulation of the SOV followed by Onyx embolization may be the best treatment option in patients with CCFs when all other endovascular approaches have been exhausted.