Brandon C Gabel

Comparison of endoscopic and microscopic removal of pituitary adenomas: single-surgeon experience and the learning curve.

OBJECT The endoscopic endonasal approach for resection of pituitary lesions is an effective surgical option for tumors of the sella turcica. In this study the authors compared outcomes after either purely endoscopic resection or traditional microscope-aided resection. They also attempted to determine the learning curve associated with a surgical team converting to endoscopic techniques. METHODS Retrospective data were collected on patients who were surgically treated for a pituitary lesion at the Hospital of the University of Pennsylvania between July 2003 and May 2008. Age, sex, race, presenting symptoms, length of hospital stay, surgical approach, duration of surgery, tumor pathological features, gross-total resection (GTR) of tumor, recurrence of the lesion, and intraoperative and postoperative complications were noted. All procedures were performed by the same senior neurosurgeon, who was initially unfamiliar with the endoscopic endonasal approach. RESULTS A total of 25 patients underwent microscopic resection and 25 patients underwent endoscopic resection performed by a single skull base team consisting of the same senior neurosurgeon and otorhinolaryngologist (M.S.G. and B.W.O.). In the microscopically treated cohort, there were 8 intra- or postoperative complications, 6 intraoperative CSF leaks, 17 (77%) of 22 patients had GTR on postoperative imaging, 5 patients underwent >or= 2 operations, and 10 (59%) of 17 patients reported total symptom resolution at follow-up. The endoscopically treated group had 7 intraor postoperative complications and 7 intraoperative CSF leaks. Of the patients who had pre- and postoperative imaging studies, 14 (66%) of 21 endoscopically treated patients had GTR; 4 patients had >or= 2 operations, and 10 (66%) of 15 patients reported complete symptom resolution at follow-up. The first 9 patients who were treated endoscopically had a mean surgical time of 3.42 hours and a mean hospital stay of 4.67 days. The next 8 patients treated had a mean surgical time of 3.11 hours and a mean hospital stay of 3.13 days. The final 8 patients treated endoscopically had a mean surgical time of 2.22 hours and a mean hospital stay of 3.88 days. The difference in length of operation between the first 9 and the last 8 patients treated endoscopically was significantly different. There was a trend toward decreased CSF leaks and other complications from the first 2 groups compared with the third group. CONCLUSIONS In this subset of patients, the use of endoscopic endonasal resection results in a similar complication and symptom resolution rate compared with traditional techniques. The authors postulate that the learning curve for endoscopic resection can be </= 17 procedures.

Surgical Treatment of Brain Tumors in Infants Younger than Six Months of Age and Review of the Literature

OBJECTIVE Brain tumors are rare in infants who are younger than six months of age. These tumors can be challenging to treat surgically. We analyzed a modern series of patients treated by a multidisciplinary team at a tertiary care center and performed a literature review of this unique population. METHODS Retrospective clinical data were collected for patients surgically treated for intracranial mass lesions at The Childrens Hospital of Philadelphia from 1998 to 2007. Dermoid cysts and other skull-based lesions were excluded from the analysis. RESULTS Sixteen patients younger than six months of age underwent surgery for primary intracranial mass lesions. The median age of the patients at surgery was 5.2 months (range, 1.4-6 months of age). Children most often presented with a bulging fontanelle, hydrocephalus, or macrocephaly (seven patients). Vomiting was seen in five patients, cranial nerve palsies in one patient, and seizures in three patients. All patients had tumor resections and postoperatively were monitored in the intensive care unit. The final pathology consisted of atypical teratoid/rhabdoid tumor (three patients), primitive neuroectodermal tumor/medulloblastoma (three patients), choroid plexus papilloma (two patients), astrocytoma (two patients), ganglioglioma (two patients), desmoplastic infantile ganglioglioma (two patients), glioblastoma multiforme (one patient), and choroid plexus carcinoma (one patient). Two intraoperative deaths occurred. Of the surviving 14, a gross total resection was achieved in four. Adjuvant therapy was determined by a multidisciplinary team composed of neuro-oncology, neurosurgery, and radiation oncology. Seven patients were treated with chemotherapy, and one patient had proton beam therapy. Five-year overall survival was 45%. The eight surviving patients had neurological sequelae, and developmental outcome was variable. CONCLUSIONS Brain tumors are uncommon in children younger than six months of age. Patients present with a variety of tumor pathologies. Children who survive have neurological sequelae. More studies are necessary to understand the impact that different treatment options, tumor pathology, and tumor location have on neurological outcome.

Symptomatic high-flow arteriovenous fistula after a C-2 fracture. Case report.

Spinal arteriovenous fistulas (AVFs) are relatively uncommon lesions that are often diagnosed in a delayed fashion. The authors present a cause of a symptomatic high-flow AVF that developed in a patient after traumatic injury to the upper cervical spine. The patient presented to the trauma bay after a motor vehicle collision, and was found to have a C-2 fracture involving the transverse foramen. Although the patient was neurologically intact on presentation, 6 hours after admission weakness developed on his left side. Imaging studies demonstrated complete transection of the distal cervical aspect of the right vertebral artery (VA) at the base of C-2, with antegrade and retrograde flow into a direct AVF, resulting in early filling of the right internal jugular vein and other external draining veins. The patient was treated endovascularly with coil occlusion of the VA both proximal and distal to the transection. The patients weakness improved over the next 7 days. At the 12-week follow-up examination, the patients fractures had healed and he was neurologically intact.

172 A Phase I, Open-Label, Single-Site, Safety Study of Human Spinal Cord-Derived Neural Stem Cell Transplantation for the Treatment of Chronic Spinal Cord Injury.

INTRODUCTION Spinal cord injury (SCI) resulting in paraplegia or quadriplegia is a significant burden in the world. It is estimated that there are approximately 250 000 people living with SCI in the United States alone. Our study offered the direct implantation of human-derived stem cells into the spinal cord of subjects who have chronic SCI. The primary objective of the study is to determine the safety and toxicity of human spinal stem cell transplantation for the treatment of paralysis. The secondary objectives of the study are to evaluate (1) graft survival in the transplant site, (2) effectiveness of transient immunosuppression as determined by absence of donor-specific HLA antibodies, and (3) potential therapeutic role of implantation on motor and sensory function in SCI. METHODS This is a phase I, open-label, single-site, study of human spinal cord-derived neural stem cell (HSSC) transplantation for the treatment of chronic SCI. Four subjects with chronic SCI with ASIA A SCI who met eligibility criteria were enrolled. All subjects received spinal cord injections of HSSC. The treatment consisted of removal of spinal instrumentation followed by direct injections into spinal parenchyma. Six HSSC injections were administered in each subject. Each injection consisted of 2 × 10 cells in 10 µL. RESULTS Four subjects have been implanted to date. All subjects tolerated the procedure well and there have been no major adverse events to date. Prospective data has been collected including ISNCSCI scores, ASIA level, functional and pain surveys, SCIM scores, Sensory and Motor Evoked potentials, EMG, and MRI including a novel sequence of MR spinal diffusion tensor imaging (DTI). These metrics are continuing to be collected and evaluated. CONCLUSION We can conclude that (1) HSSC transplanted into the injury site of a spinal cord in chronic spinal cord injury patients can be done safely. (2) The HSSC graft has been shown to have no major adverse events to date.

Potent spinal parenchymal AAV9-mediated gene delivery by subpial injection in adult rats and pigs

Effective in vivo use of adeno-associated virus (AAV)-based vectors to achieve gene-specific silencing or upregulation in the central nervous system has been limited by the inability to provide more than limited deep parenchymal expression in adult animals using delivery routes with the most clinical relevance (intravenous or intrathecal). Here, we demonstrate that the spinal pia membrane represents the primary barrier limiting effective AAV9 penetration into the spinal parenchyma after intrathecal AAV9 delivery. We develop a novel subpial AAV9 delivery technique and AAV9-dextran formulation. We use these in adult rats and pigs to show (i) potent spinal parenchymal transgene expression in white and gray matter including neurons, glial and endothelial cells after single bolus subpial AAV9 delivery; (ii) delivery to almost all apparent descending motor axons throughout the length of the spinal cord after cervical or thoracic subpial AAV9 injection; (iii) potent retrograde transgene expression in brain motor centers (motor cortex and brain stem); and (iv) the relative safety of this approach by defining normal neurological function for up to 6 months after AAV9 delivery. Thus, subpial delivery of AAV9 enables gene-based therapies with a wide range of potential experimental and clinical utilizations in adult animals and human patients.

An Algorithm to Predict Success of Indirect Decompression Using the Extreme Lateral Lumbar Interbody Fusion Procedure.

Purpose: The purpose of this study is to define an algorithm that will predict the success of indirect decompression without the need for direct decompression in patients undergoing lateral lumbar interbody fusions. Methods and Materials: A prospective cohort study was undertaken for patients undergoing indirect decompression with lateral lumbar interbody fusion. Patients had to meet the following criteria prior to indirect fusion: lack of facet fusion on CT, absence of free disc fragment or compressive facet joint cyst on MRI, absence of frank osteoporosis, lack of congenital and/or severe spinal stenosis on MRI, and significant reduction (greater than 50%) in leg and back pain at rest. We then assessed which patients at follow-up required a second stage open decompression procedure because of continued back and/or leg pain. Results: Our series included 28 patients who underwent indirect decompression with extreme lateral lumbar interbody fusion. Of the 28 patients, one patient required a second stage open decompression at follow-up. The most common level operated on was the L4-L5 level. Twelve patients underwent more than a single level fusion. Average preoperative lumbar lordosis was 29 degrees and average postoperative lordosis was 45 degrees. The average patient age was 66.3 years and average follow-up was 1.21 years. Conclusions: Our algorithm can be used as an aid to assess which patients may benefit from indirect decompression alone, compared to indirect decompression combined with posterior decompression procedures.

Relationship of the lumbar plexus branches to the lumbar spine: anatomical study with application to lateral approaches

BACKGROUND CONTEXT Injuries to the lumbar plexus during lateral approaches to the spine are not uncommon and may result in permanent deficits. However, the literature contains few studies that provide landmarks for avoiding the branches of the lumbar plexus. PURPOSE The present anatomical study was performed to elucidate the course of these nerves in relation to lateral approaches to the lumbar spine. STUDY DESIGN This is a quantitative anatomical cadaveric study. METHODS The lumbar plexus and its branches were dissected on 12 cadaveric sides. Metal wires were laid on the nerves along their paths on the posterior abdominal wall. Fluoroscopy was performed in the anteroposterior and lateral positions. The relationships between regional bony landmarks and the branches of the lumbar plexus were observed. RESULTS When viewed laterally, the greatest concentration of nerves occurred from the posteroinferior aspect of L4, inferior along the posterior one-third of the body of L5, then at the level of the sacral promontory. On the basis of our study, approaches to the anterior two-thirds of the L4 vertebra and anterior third of L5 will result in the lowest chance of lumbar plexus nerve injury. In addition, lateral muscle dissection through the psoas major should be in a superior to inferior direction in order to minimize nerve injury. Laterally, the widest corridor between branches in the abdominal wall was between the subcostal and iliohypogastric nerves. CONCLUSIONS The findings of our cadaveric study provide surgeons who approach the lateral lumbar spine with data that could decrease injuries to the branches of the lumbar plexus, thus lessening patient morbidity.

Questioning the need for ICU level of care in pediatric patients following elective uncomplicated craniotomy for brain tumors.

OBJECTIVE The object of this study is to address what factors may necessitate the need for intensive care monitoring after elective uncomplicated craniotomy in pediatric patients who are initially managed in a non-intensive care unit setting postoperatively. METHODS A retrospective chart review was undertaken for all patients who underwent elective craniotomy for brain tumor between April of 2007 and April of 2012 and who were directly admitted to the floor postoperatively. Factors such as age, tumor type, craniotomy location, neurological comorbidities, reason for transfer to intensive care unit (ICU) level of care (if applicable), time between admittance to floor and transfer to ICU level of care, and reason for transfer to ICU level of care were assessed. RESULTS Adjusted logistic regression found 2 significant positive predictors of postoperative transfer to the ICU after initial admission to the floor: primitive neuroectodermal tumor pathology (OR 44.10, 95% CI 1.24-1572.16, p = 0.04), and repeat craniotomy during the same hospitalization (OR 13.97, 95% CI 1.21-160.66, p = 0.03). Conversely, 1 negative factor was found: low-grade glioma pathology (OR 0.05, 95% CI 0.00-0.87, p = 0.04). CONCLUSIONS Select pediatric patients may not require ICU level of care after elective uncomplicated pediatric craniotomy. Additional studies are needed to adequately address which patients would benefit from initial ICU admittance following elective craniotomies for brain tumors.

A Review of Stem Cell Therapy for Spinal Cord Injury: Large Animal Models and the Frontier in Humans.

OBJECTIVE To review the literature of spinal cord injury and stem cell therapy for large animal models and incorporate those results into an understanding of stem cell therapy for human cord injury. METHODS Review of the literature. RESULTS Eleven canine studies were identified and 3 sub-human primate studies were identified showing variable results. CONCLUSIONS Stem cell therapy is a promising therapeutic option for patients with spinal cord injury; however, the technology has many un-answered questions and further research is needed.

Low-profile Visualized Intraluminal Support Junior Device for the Treatment of Intracranial Aneurysms.

Objective: Early case series suggest that the recently introduced Low-profile Visualized Intraluminal Support Junior (LVIS Jr.) device (MicroVention-Terumo, Inc., Tustin, CA) may be used to treat wide-necked aneurysms that would otherwise require treatment with intrasaccular devices or open surgery. We report our single-center experience utilizing LVIS Jr. to treat intracranial aneurysms involving 1.8-2.5 mm parent arteries. Methods: We retrospectively reviewed records of patients treated with the LVIS Jr. device for intracranial aneurysms at a single center. A total of 21 aneurysms were treated in 18 patients. Aneurysms were 2-25 mm in diameter; one was ruptured, while three had recurred after previous rupture and treatment. Lesions were distributed across the anterior (n=12) and posterior (n=9) circulations. Three were fusiform morphology. Results: Stent deployment was successful in 100% of cases with no immediate complications. Seventeen aneurysms were treated with stent-assisted coil embolization resulting in immediate complete occlusion in 94% of cases. Two fusiform aneurysms arising from the posterior circulation were further treated with elective clip ligation after delayed expansion and recurrence; no lesions required further endovascular treatment. Four aneurysms were treated by flow diversion with stand-alone LVIS Jr. stent, and complete occlusion was achieved in three cases. Small foci of delayed ischemic injury were noted in two patients in the setting of antiplatelet medication noncompliance. No in-stent stenosis, migration, hemorrhage, or permanent deficits were observed. Good functional outcome based on the modified Rankin Scale score (mRS ≤ 2) was achieved in 100% of cases. Conclusion: Our midterm results suggest that the LVIS Jr. stent may be used for a variety of intracranial aneurysms involving small parent arteries (1.8-2.5 mm) with complete angiographic occlusion, parent vessel preservation, and functional clinical outcomes. This off-label expansion would increase the number of aneurysms amenable to endovascular treatment. Future studies may build upon our experiences with flow diversion and treatment of complex or multiple lesions.