Browse

You are looking at 51 - 60 of 96 items for

  • Refine by Access: all x
  • By Author: Nakaji, Peter x
Clear All
Restricted access

Douglas A. Hardesty, Wyatt Ramey, Mohammad Afrasiabi, Brian Beck, Omar Gonzalez, Ana Moran, and Peter Nakaji

Object

Coccidioidomycosis is a common fungal infection in the southwestern US. Hydrocephalus is a serious complication of cranial coccidioidomycosis, and the surgical management of coccidioidomycosis-related hydrocephalus has unique challenges. The authors reviewed their institutional experience with hydrocephalus in the setting of coccidioidomycosis.

Methods

The authors retrospectively identified 44 patients diagnosed with coccidioidomycosis-related hydrocephalus at their institution since 1990, who underwent a total of 99 shunting procedures. The authors examined patient demographics, type of shunt and valve used, pressure settings, failure rates, medical treatment, ventricular response to shunting, and other variables.

Results

The majority of patients were young (average age 37 years) men (male/female ratio 28:16) with a mean follow-up of 63 months. Patients of Asian and African descent were overrepresented in the cohort compared with regional demographic data. The overall shunt failure rate during follow-up was 50%, and the average number of revisions required if the shunt failed was 2.5 (range 1–8). Low to moderate draining pressures (mean 88 mm H2O) were used in this cohort. Fourteen patients received intrathecal antifungals, and a trend of initiating intrathecal therapy after need for a shunt revision was observed (p = 0.051). The majority of shunt failures (81%) were due to mechanical blockages in the drainage system. Most patients (59%) had at least partial persistent postoperative ventriculomegaly despite successful CSF diversion. Four patients (9%) died due to coccidioidomycosis during the follow-up period.

Conclusions

Coccidioidomycosis-related hydrocephalus more often affected young males in the study's cohort, especially those of African and Asian descent. Despite the best medical therapy, there was a high rate of shunt failure due to clogged catheters or valves due to the underlying disease process. Many patients continued to have ventriculomegaly even with adequate CSF diversion. The morbidity and mortality of this chronic disease process must be recognized by the treatment team, and patients should be appropriately counseled.

Free access

Leonardo Rangel-Castilla, Jonathan J. Russin, Hasan A. Zaidi, Eduardo Martinez-del-Campo, Min S. Park, Felipe C. Albuquerque, Cameron G. McDougall, Peter Nakaji, and Robert F. Spetzler

Object

Spinal arteriovenous fistulas (AVFs) and arteriovenous malformations (AVMs) are rare, complex spinal vascular lesions that are challenging to manage. Recently, understanding of these lesions has increased thanks to neuroimaging technology. Published reports of surgical results and clinical outcome are limited to small series. The authors present a large contemporary series of patients with spinal AVFs and AVMs who were treated at Barrow Neurological Institute in Phoenix, Arizona.

Methods

Retrospective detailed review of a prospective vascular database was performed for all patients with spinal AVFs and AVMs treated between 2000 and 2013. Patient demographic data, AVF and AVM characteristics, surgical results, clinical outcomes, complications, and long-term follow-up were reviewed.

Results

Between 2000 and 2013, 110 patients (57 male and 53 female) underwent obliteration of spinal AVFs and AVMs. The mean age at presentation was 42.3 years (range 18 months–81 years). There were 44 patients with AVFs and 66 with AVMs. The AVM group included 27 intramedullary, 21 conus medullaris, 12 metameric, and 6 extradural. The most common location was thoracic spine (61%), followed by cervical (22.7%), lumbar (14.5%), and sacral (1.8%). The most common presenting signs and symptoms included paresis/paralysis (75.5%), paresthesias (60%), pain (51.8%), bowel/bladder dysfunction (41.8%), and myelopathy (36.4%). Evidence of rupture was seen in 26.4% of patients. Perioperative embolization was performed in 42% of patients. Resection was performed in 95 patients (86.4%). Embolization alone was the only treatment in 14 patients (12.7%). One patient was treated with radiosurgery alone. Angiographically verified AVF and AVM obliteration was achieved in 92 patients (83.6%). At a mean follow-up duration of 30.5 months (range 1–205 months), 43 patients (97.7%) with AVFs and 57 (86.4%) with AVMs remained functionally independent (McCormick Scale scores ≤ 2). Perioperative complications were seen in 8 patients (7%). No deaths occurred. Temporary neurological deficits were observed in 27 patients (24.5%). These temporary deficits recovered 6–8 weeks after treatment. Recurrence was identified in 6 patients (13.6%) with AVFs and 10 (15.2%) with AVMs.

Conclusions

Spinal AVFs and AVMs are complex lesions that should be considered for surgical obliteration. Over the last several decades the authors have changed surgical strategies and management to achieve better clinical outcomes. Transient neurological deficit postoperatively is a risk associated with intervention; however, clinical outcomes appear to exceed the natural history based on patients’ ability to recover during the follow-up period. Due to the recurrence rate associated with these lesions, long-term follow-up is required.

Free access

Leonardo Rangel-Castilla, Jonathan J. Russin, Eduardo Martinez-del-Campo, Hector Soriano-Baron, Robert F. Spetzler, and Peter Nakaji

Object

Arteriovenous malformations (AVMs) are classically described as congenital static lesions. However, in addition to rupturing, AVMs can undergo growth, remodeling, and regression. These phenomena are directly related to cellular, molecular, and physiological processes. Understanding these relationships is essential to direct future diagnostic and therapeutic strategies. The authors performed a search of the contemporary literature to review current information regarding the molecular and cellular biology of AVMs and how this biology will impact their potential future management.

Methods

A PubMed search was performed using the key words “genetic,” “molecular,” “brain,” “cerebral,” “arteriovenous,” “malformation,” “rupture,” “management,” “embolization,” and “radiosurgery.” Only English-language papers were considered. The reference lists of all papers selected for full-text assessment were reviewed.

Results

Current concepts in genetic polymorphisms, growth factors, angiopoietins, apoptosis, endothelial cells, pathophysiology, clinical syndromes, medical treatment (including tetracycline and microRNA-18a), radiation therapy, endovascular embolization, and surgical treatment as they apply to AVMs are discussed.

Conclusions

Understanding the complex cellular biology, physiology, hemodynamics, and flow-related phenomena of AVMs is critical for defining and predicting their behavior, developing novel drug treatments, and improving endovascular and surgical therapies.

Restricted access

Jason P. Sheehan, Robert M. Starke, Hideyuki Kano, Anthony M. Kaufmann, David Mathieu, Fred A. Zeiler, Michael West, Samuel T. Chao, Gandhi Varma, Veronica L. S. Chiang, James B. Yu, Heyoung L. McBride, Peter Nakaji, Emad Youssef, Norissa Honea, Stephen Rush, Douglas Kondziolka, John Y. K. Lee, Robert L. Bailey, Sandeep Kunwar, Paula Petti, and L. Dade Lunsford

Object

Parasellar and sellar meningiomas are challenging tumors owing in part to their proximity to important neurovascular and endocrine structures. Complete resection can be associated with significant morbidity, and incomplete resections are common. In this study, the authors evaluated the outcomes of parasellar and sellar meningiomas managed with Gamma Knife radiosurgery (GKRS) both as an adjunct to microsurgical removal or conventional radiation therapy and as a primary treatment modality.

Methods

A multicenter study of patients with benign sellar and parasellar meningiomas was conducted through the North American Gamma Knife Consortium. For the period spanning 1988 to 2011 at 10 centers, the authors identified all patients with sellar and/or parasellar meningiomas treated with GKRS. Patients were also required to have a minimum of 6 months of imaging and clinical follow-up after GKRS. Factors predictive of new neurological deficits following GKRS were assessed via univariate and multivariate analyses. Kaplan-Meier analysis and Cox multivariate regression analysis were used to assess factors predictive of tumor progression.

Results

The authors identified 763 patients with sellar and/or parasellar meningiomas treated with GKRS. Patients were assessed clinically and with neuroimaging at routine intervals following GKRS. There were 567 females (74.3%) and 196 males (25.7%) with a median age of 56 years (range 8–90 years). Three hundred fifty-five patients (50.7%) had undergone at least one resection before GKRS, and 3.8% had undergone prior radiation therapy. The median follow-up after GKRS was 66.7 months (range 6–216 months). At the last follow-up, tumor volumes remained stable or decreased in 90.2% of patients. Actuarial progression-free survival rates at 3, 5, 8, and 10 years were 98%, 95%, 88%, and 82%, respectively. More than one prior surgery, prior radiation therapy, or a tumor margin dose < 13 Gy significantly increased the likelihood of tumor progression after GKRS.

At the last clinical follow-up, 86.2% of patients demonstrated no change or improvement in their neurological condition, whereas 13.8% of patients experienced symptom progression. New or worsening cranial nerve deficits were seen in 9.6% of patients, with cranial nerve (CN) V being the most adversely affected nerve. Functional improvements in CNs, especially in CNs V and VI, were observed in 34% of patients with preexisting deficits. New or worsened endocrinopathies were demonstrated in 1.6% of patients; hypothyroidism was the most frequent deficiency. Unfavorable outcome with tumor growth and accompanying neurological decline was statistically more likely in patients with larger tumor volumes (p = 0.022) and more than 1 prior surgery (p = 0.021).

Conclusions

Gamma Knife radiosurgery provides a high rate of tumor control for patients with parasellar or sellar meningiomas, and tumor control is accompanied by neurological preservation or improvement in most patients.

Restricted access

M. Yashar S. Kalani, Ali M. Elhadi, Wyatt Ramey, Peter Nakaji, Felipe C. Albuquerque, Cameron G. McDougall, Joseph M. Zabramski, and Robert F. Spetzler

Object

Aneurysms are relatively rare in the pediatric population and tend to include a greater proportion of large and giant lesions. A subset of these large and giant aneurysms are not amenable to direct surgical clipping and require complex treatment strategies and revascularization techniques. There are limited data available on the management of these lesions in the pediatric population. This study was undertaken to evaluate the outcome of treatment of large and giant aneurysms that required microsurgical revascularization and vessel sacrifice in this population.

Methods

The authors retrospectively identified all cases in which pediatric patients (age < 18 years) with aneurysms were treated using cerebral revascularization in combination with other treatment modalities at their institution between 1989 and 2013.

Results

The authors identified 27 consecutive patients (19 male and 8 female) with 29 aneurysms. The mean age of the patients at the time of treatment was 11.5 years (median 13 years, range 1–17 years). Five patients presented with subarachnoid hemorrhage, 11 with symptoms related to mass effect, 2 with stroke, and 3 with seizures; in 6 cases, the aneurysms were incidental findings. Aneurysms were located along the internal carotid artery (n = 7), posterior cerebral artery (PCA) (n = 2), anterior cerebral artery (n = 2), middle cerebral artery (MCA) (n = 14), basilar artery (n = 2), vertebral artery (n = 1), and at the vertebrobasilar junction (n = 1). Thirteen were giant aneurysms (45%). The majority of the aneurysms were fusiform (n = 19, 66%), followed by saccular (n = 10, 34%). Three cases were previously treated using microsurgery (n = 2) or an endovascular procedure (n = 1). A total of 28 revascularization procedures were performed, including superficial temporal artery (STA) to MCA (n = 6), STA to PCA (n = 1), occipital artery to PCA (n = 1), extracranial-intracranial (EC-IC) bypass using radial artery graft (n = 3), EC-IC using a saphenous vein graft (n = 7), STA onlay (n = 3), end-to-end anastomosis (n = 1), and in situ bypasses (n = 6). Perioperative stroke occurred in 4 patients, but only one remained dependent (Glasgow Outcome Scale [GOS] score 3). At a mean clinical follow-up of 46 months (median 14 months, range 1–232 months), 26 patients had a good outcome (GOS score 4 or 5). There were no deaths. Five patients had documented occlusion of the bypass graft. The majority of aneurysms (n = 24) were obliterated at last follow-up. There was a single case of a residual aneurysm and one case of recurrence. Angiographic follow-up was unavailable in 3 cases.

Conclusions

Cerebral revascularization remains an essential tool in the treatment of complex cerebral aneurysms in children.

Restricted access

Mark E. Oppenlander, Andrew B. Wolf, Laura A. Snyder, Robert Bina, Jeffrey R. Wilson, Stephen W. Coons, Lynn S. Ashby, David Brachman, Peter Nakaji, Randall W. Porter, Kris A. Smith, Robert F. Spetzler, and Nader Sanai

Object

Despite improvements in the medical and surgical management of patients with glioblastoma, tumor recurrence remains inevitable. For recurrent glioblastoma, however, the clinical value of a second resection remains uncertain. Specifically, what proportion of contrast-enhancing recurrent glioblastoma tissue must be removed to improve overall survival and what is the neurological cost of incremental resection beyond this threshold?

Methods

The authors identified 170 consecutive patients with recurrent supratentorial glioblastomas treated at the Barrow Neurological Institute from 2001 to 2011. All patients previously had a de novo glioblastoma and following their initial resection received standard temozolomide and fractionated radiotherapy.

Results

The mean clinical follow-up was 22.6 months and no patient was lost to follow-up. At the time of recurrence, the median preoperative tumor volume was 26.1 cm3. Following re-resection, median postoperative tumor volume was 3.1 cm3, equating to an 87.4% extent of resection (EOR). The median overall survival was 19.0 months, with a median progression-free survival following re-resection of 5.2 months. Using Cox proportional hazards analysis, the variables of age, Karnofsky Performance Scale (KPS) score, and EOR were predictive of survival following repeat resection (p = 0.0001). Interestingly, a significant survival advantage was noted with as little as 80% EOR. Recursive partitioning analysis validated these findings and provided additional risk stratification at the highest levels of EOR. Overall, at 7 days after surgery, a deterioration in the NIH stroke scale score by 1 point or more was observed in 39.1% of patients with EOR ≥ 80% as compared with 16.7% for those with EOR < 80% (p = 0.0049). This disparity in neurological morbidity, however, did not endure beyond 30 days postoperatively (p = 0.1279).

Conclusions

For recurrent glioblastomas, an improvement in overall survival can be attained beyond an 80% EOR. This survival benefit must be balanced against the risk of neurological morbidity, which does increase with more aggressive cytoreduction, but only in the early postoperative period. Interestingly, this putative EOR threshold closely approximates that reported for newly diagnosed glioblastomas, suggesting that for a subset of patients, the survival benefit of microsurgical resection does not diminish despite biological progression.

Free access

Cameron G. McDougall, Robert F. Spetzler, Felipe C. Albuquerque, Joseph M. Zabramski, and Peter Nakaji

Free access

Joseph Georges, Aqib Zehri, Elizabeth Carlson, Joshua Nichols, Michael A. Mooney, Nikolay L. Martirosyan, Layla Ghaffari, M. Yashar S. Kalani, Jennifer Eschbacher, Burt Feuerstein, Trent Anderson, Mark C. Preul, Kendall Van Keuren-Jensen, and Peter Nakaji

Glioblastoma is the most common primary brain tumor with a median 12- to 15-month patient survival. Improving patient survival involves better understanding the biological mechanisms of glioblastoma tumorigenesis and seeking targeted molecular therapies. Central to furthering these advances is the collection and storage of surgical biopsies (biobanking) for research. This paper addresses an imaging modality, confocal reflectance microscopy (CRM), for safely screening glioblastoma biopsy samples prior to biobanking to increase the quality of tissue provided for research and clinical trials. These data indicate that CRM can immediately identify cellularity of tissue biopsies from animal models of glioblastoma. When screening fresh human biopsy samples, CRM can differentiate a cellular glioblastoma biopsy from a necrotic biopsy without altering DNA, RNA, or protein expression of sampled tissue. These data illustrate CRM's potential for rapidly and safely screening clinical biopsy samples prior to biobanking, which demonstrates its potential as an effective screening technique that can improve the quality of tissue biobanked for patients with glioblastoma.

Free access

Michael A. Mooney, Aqib H. Zehri, Joseph F. Georges, and Peter Nakaji

Laser scanning confocal endomicroscopy (LSCE) is an emerging technology for examining brain neoplasms in vivo. While great advances have been made in macroscopic fluorescence in recent years, the ability to perform confocal microscopy in vivo expands the potential of fluorescent tumor labeling, can improve intraoperative tissue diagnosis, and provides real-time guidance for tumor resection intraoperatively. In this review, the authors highlight the technical aspects of confocal endomicroscopy and fluorophores relevant to the neurosurgeon, provide a comprehensive summary of LSCE in animal and human neurosurgical studies to date, and discuss the future directions and potential for LSCE in neurosurgery.