Thoracic Endovascular Aortic Repair for Iatrogenic Injury of the Thoracic Aorta.

PURPOSE: Address iatrogenic injury to the descending thoracic aorta by breached spinal screws through a novel approach of concomitant spinal screw removal and thoracic endovascular repair (TEVAR) placement. CASE REPORT: A 36-year-old female with idiopathic scoliosis underwent T4 to L3 bilateral pedicle instrumentation with spinal fusion and correction of scoliosis deformity. Ten months post-operative, she continued to complain of mid-thoracic pain; computed tomography (CT) angiography revealed protrusion of the left T5 and T6 transpedicular screws into her descending thoracic aorta by 3 and 5 mm, respectively. She was taken to the odds ratio (OR) in a combination case with vascular and neurosurgery. Positioned in the right lateral decubitus position, TEVAR was successfully deployed while neurosurgery concurrently removed the invading spinal screws via posterior spinal exposure. Neurosurgery then completely revised the spinal hardware during the same operation. The patient progressed well throughout the remainder of her hospital stay and was discharged on postoperative day 4. Two-year angiography demonstrated a well-placed TEVAR with no extravasation or aortic abnormality. CONCLUSIONS: In the setting of iatrogenic aortic injury due to pedicle screws, concomitant TEVAR and spinal screw removal is a safe and feasible treatment option that allows for spinal reconstruction to occur without multiple trips to the operating room.

Establishing a Standardized Method for the Effective Intraoperative Collection and Biological Preservation of Brain Tumor Tissue Samples Using a Novel Tissue Preservation System: A Pilot Study.

BACKGROUND: Glioblastoma (GB) is an aggressive tumor showing extensive intertumoral and intratumoral heterogeneity. Several possible reasons contribute to the historical inability to develop effective therapeutic strategies for treatment of GB. One such challenge is the inability to consistently procure high-quality biologically preserved specimens for use in molecular research and patient-derived xenograft model development. No scientifically derived standardized method exists for intraoperative tissue collection specifically designed with the fragility of RNA in mind. METHODS: In this investigation, we set out to characterize matched specimens from 6 GB patients comparing the traditional handling and collection processes of intraoperative tissue used in most neurosurgical operating rooms versus an automated resection, collection, and biological preservation system (APS) which captures, preserves, and biologically maintains tissue in a prescribed and controlled microenvironment. Matched specimens were processed in parallel at various time points and temperatures, evaluating viability, RNA and protein concentrations, and isolation of GB cell lines. RESULTS: We found that APS-derived GB slices stored in an APS modified medium remained viable and maintained high-quality RNA and protein concentration for up to 24 hours. CONCLUSIONS: Our results showed that primary GB cell cultures derived in this manner had improved growth over widely used collection and preservation methods. By implementing an automated intraoperative system, we also eliminated inconsistencies in methodology of tissue collection, handling and biological preservation, establishing a repeatable and standardized practice that does not require additional staff or a laboratory technician to manage it.

Analysis of the P53N a Novel Protein Encoded on Chromosome 22q12.1-12.3 in Glioblastomas and Ependymomas Specimens.

The P53N gene maps precisely to human chromosome sub-band 22q12.1-12.3, a region where loss of heterozygosity has been reported in 30% of astrocytic tumors and associated with progression to anaplasia. Moreover, a putative tumor suppressor gene has been indicated on 22q11 region involved in pathogenesis of ependymal tumors. Our objectives to examine the expression level of novel membrane-associated protein (termed P53N) encoded by a novel human gene on chromosome 22q12.1-12.3 in glioblastomas and ependymomas. Serial analysis of gene expression (SAGE) and immunofluorescence analysis of the P53N in the brain tumor tissues were performed. Our analysis revealed that there was high expression of the P53N mRNA in brain ependymoma and brain well-differentiated astrocytoma libraries. The P53N protein. P53N protein contains a high mobility group (HMG) domain at amino acid positions 301 to 360 expressed highly in glioblastoma and ependymoma specimens. Anti-P53N carboxyl-terminal peptide antibody localized the P53N protein to the cytoplasmic membranes of protoplasmic astrocytes in the glioblastoma and ependymoma specimens. These results are in good agreement with the SAGE analysis and the predicted transmembrane topology for the P53N protein and support a possible transmembrane model in which the P53N contains a predicted transmembrane region with its amino terminus localized to the inside of the cytoplasmic membrane.

Clinical outcomes for patients with lateral lumbar radiculopathy treated by percutaneous endoscopic transforaminal discectomy versus tubular microdiscectomy: A retrospective review.

BACKGROUND: Surgical management of lateral lumbar radiculopathy is evolving. TMD (Tubular microdiscectomy) and TELD (Transforaminal endoscopic lumbar discectomy) have emerged as viable MIS treatments. We aim to compare clinical outcomes of both techniques for the treatment of lateral lumbar radiculopathy in relation to pre-operative lumbar foraminal stenosis grade (LFS). METHODS: Retrospective observational cohort study of patients with back and leg pain from single level foraminal nerve root compression that underwent TMD or TELD. Data analyzed included pre- and post-operative VAS leg and back pain, MacNab clinical outcome scores, hospital length of stay, complication rates, and operative time. Outcomes were correlated with a pre-operative MRI grading system for LFS. RESULTS: 109 patients were enrolled (71 TELD and 38 TMD). Back and leg VAS pain scores improved in TELD and TMD (p < 0.0001). Patients with grade III stenosis showed significantly higher VAS scores (p < 0.01), and worse functional outcomes at latest follow-up compared with grade I/II LFS. Overall, there was no difference in outcome between procedure groups except that TMD VAS back pain scores were lower than TELD at last follow up (p < 0.05). Clinical outcome comparisons between procedures relating to LFS grade showed higher correlation of LFS to TELD (Spearman's rho (ρ)= 0.342 for TMD and 0.606 TELD). Regression analyses demonstrated correlation between higher-grade foraminal stenosis and poorer outcomes in TELD and TMD. CONCLUSIONS: Both TELD and TMD are viable for treating lateral lumbar radiculopathy. Higher-grade foraminal stenosis can be indicative of poorer outcomes regardless of procedure type, however, the severity of pre-operative LFS correlates with clinical outcomes in TELD more significantly than TMD.

Targeting Subventricular Zone Progenitor Cells with Intraventricular Liposomal Encapsulated Cytarabine in Patients with Secondary Glioblastoma : A Report of Two Cases.

BACKGROUND: Current treatments for glioblastoma (GB), the most common and malignant primary brain tumor are inadequate and as such, the median survival for most patients with GB is on the order of months, even after cytoreductive surgery, radiation and chemotherapy. CASE DESCRIPTION: Current study reports two cases of glioblastoma (GB) with subventricular zone (SVZ) involvement. SVZ biopsies demonstrated the presence of hypercellularity, nestin immunoreactivity, and a Ki-67 labeling index (LI) of 1-2%. Interestingly, tumor morphology and proliferative indices are different in the SVZ specimens than the hemispheric recurrences, which displayed similar nestin immunoreactivity, but a greater LI of 10%. Biopsy specimens demonstrated both intense nestin immunoreactivity and GFAP immunoreactivity in and around the GB recurrence. Nestin positive cells were more abundant closer to the SVZ nearest to the dorsolateral horn of the left lateral ventricle, while GFAP immunoreactivity was more intense closer to the center of the tumor recurrence. Additionally, co-labeling of cells with Ki67 and several different progenitor markers (CD133, CD140, TUJ-1, and nestin) demonstrated that these cells found in and around the GB recurrence were actively dividing. Having failed standard therapy with evidence of bi-hemispheric spread and progression to GB, we report a novel approach of using intraventricular liposomal encapsulated cytarabine (DepoCyt) for the treatment for GB by suppressing glial progenitor cells that surround the ventricular system in patients with GB. CONCLUSIONS: MRI and immunohistochemistry demonstrated that the SVZ is the incubator for future recurrences of GB and propose targeting SVZ progenitor cells with intraventricular liposomal encapsulated Ara-C. Two patients treated using this novel regimen have demonstrated partial radiographic responses warranting further studies looking at targeting the subventricular zone.

Analysis of P78: A Novel Cytoplasmic Membrane-Associated Protein Encoded on Chromosome 19q13.3 in Glioma Specimens.

Allelic losses of the q13.3 region of chromosome 19 have been documented in all major types of diffuse gliomas, strongly suggesting the presence of a 19q13.3 tumor suppressor gene responsible for these malignancies. The P78 gene precisely maps to 19q13.3, the glioma candidate region, and encodes a recently identified novel protein (P78). The purpose of this study was to determine P78 protein expression in gliomas. Serial analysis of gene expression (SAGE) reveals P78 mRNA expression to be significantly reduced in high-grade gliomas such as glioblastoma (GB), as compared with the low-grade tumors including astrocytomas, oligodendrogliomas, and ependymomas. We observed the distribution of staining of P78 protein was concentrated on the cell membranes of the luminal epithelial cells, not cytoplasm. In contrast, the pre-immune serum controls demonstrated no staining. These results demonstrate that P78 protein is highly expressed in the cytoplasmic membranes of low but not high-grade astrocytomas, and correlates with grade of malignancy. In these double immunostaining experiments, the anti-Map-2 and anti-NeuN antibodies did not stain round cells that were stained with the anti-P78 carboxyl-terminal peptide antibodies, demonstrating that these round cells were not neurons, and likely protoplasmic astrocytes. Current results also suggest that the astrocytes stained with the anti-P78 carboxyl-terminal peptide antibody are likely protoplasmic astrocytes. We also observed preincubation of anti-P78 carboxyl-terminal antibodies with immunizing peptides abolished immunostaining in gliomas. These results suggest a role for the P78 protein in the process of abnormal growth in glial tumors.

Strategies for posterior-only minimally invasive surgery in thoracolumbar metastatic epidural spinal cord compression.

BACKGROUND: Metastatic epidural spinal cord compression (MESCC) is a debilitating sequela of cancer. Here, we evaluated various subtypes of posterior-only minimally invasive spinal (MIS) procedures utilized to address different cancers. METHODS: Within this retrospective review, we analyzed the treatment of thoracolumbar MESCC treated with three MIS techniques: decompression and fusion (Subgroup A), partial corpectomy (Subgroup B), and full corpectomy (Subgroup C). RESULTS: There were 51 patients included in the study; they averaged 58.7 years of age, and 51% were females. Most tumors were in the thoracic spine (51%). The average preoperative Frankel grade was D (62.7%); 69% (35) improved postoperatively. The patients were divided as follows: subgroup A (15 patients = 29.4%), B (19 patients = 37.3%), and C (17 patients = 33.3%). The length of hospitalization was similar (~5.4 days) for all groups. The overall complication rate was 31%, while blood loss was lower in Subgroups A and B versus C. CONCLUSION: Different MIS surgical techniques were utilized in patients with thoracic and/or lumbar MESCC. Interestingly, clinical outcomes were similar between MIS subgroups, in this study, with a trend toward higher complications and greater blood loss associated with those undergoing more aggressive MIS procedures (e.g., full corpectomy and fusion).

Case-based review: ependymomas in adults.

Ependymomas are rare primary central nervous system (CNS) tumors in adults. They occur most commonly in the spinal cord, and have classically been graded histologically into World Health Organization (WHO) grades I, II, or III based on the level of anaplasia. Recent data are showing that genetic heterogeneity occurs within the same histological subgroup and that ependymomas arising from different CNS locations have different molecular signatures. This has renewed interest in developing targeting therapies based on molecular profiles especially given the variable outcomes with radiation and the poor results with cytotoxic agents. In this paper, we present the case of a 46-year-old woman with a classic presentation of spinal cord ependymoma and discuss the current histopathological and molecular classification for ependymomas as well as current guidelines for patient management.

Percutaneous vertebral augmentation: an elevation in adjacent-level fracture risk in kyphoplasty as compared with vertebroplasty.

BACKGROUND CONTEXT: Osteoporotic vertebral compression fractures (VCFs) are being increasingly treated with minimally invasive bone augmentation techniques such as kyphoplasty and vertebroplasty. Both are reported to be an effective means of pain relief; however, there may be an increased risk of developing subsequent VCFs after such procedures. PURPOSE: The purpose of this study was to compare the effectiveness and complication profile of kyphoplasty and vertebroplasty in a single patient series. STUDY DESIGN/SETTING: A clinical series of 36 patients with VCFs treated by vertebral augmentation procedures was retrospectively analyzed for surgical approach, volume of cement injected, cement extravasation (symptomatic and asymptomatic), the occurrence of subsequent adjacent level fracture, and pain relief. PATIENT SAMPLE: Thirty-six patients with 46 VCFs underwent either kyphoplasty or vertebroplasty after failing conservative therapy. The mean patient age was not significantly different between the kyphoplasty group (70; range, 46-83) and vertebroplasty group (72; range, 38-90) (p=.438). OUTCOME MEASURES: Outcomes were assessed by using self-report measures (a comparative pain rating scale) and physiologic measures (pre- and postoperative radiographs). METHODS: Thirty-six patients with VCFs underwent 46 augmentation procedures (17 patients had 20 fractures treated via kyphoplasty, and 19 patients had 26 fractures treated via vertebroplasty). Seventeen patients in this series underwent kyphoplasty using standard techniques involving bone void creation with balloon tamps, followed by cement injection. Nineteen patients underwent a percutaneous vertebroplasty procedure using a novel cannulated, fenestrated bone tap developed to direct cement anteriorly into the vertebral body to avoid backflow of cement onto neural elements. RESULTS: Pain improvement was seen in >90% of patients in both groups. Mean cement injection per vertebral body was 4.65 mL and 3.78 mL for the kyphoplasty and vertebroplasty groups, respectively (p=.014). Ninety-five percent of the kyphoplasty procedures were performed bilaterally, whereas only 19% of the vertebroplasty procedures required bilateral augmentation (p<.001). There was no cement extravasation resulting in radiculopathy, or myelopathy in either group. Asymptomatic cement extravasation was seen in 5 of 46 (11%) of the total series (3/20 [15%] and 2/26 [7.7%] of kyphoplasty and vertebroplasty, respectively) (p=.696). Within a 3-month period, there were 5 new adjacent level fractures seen in 3 patients who underwent a kyphoplasty procedure (5/20 [25%]) and none in the vertebroplasty group (p<.05). CONCLUSIONS: Vertebroplasty appears to offer a comparable rate of postoperative pain relief as kyphoplasty while using less bone cement more often via a unilateral approach and without the attendant risk of adjacent level fracture.

A biomechanical cadaveric analysis of polymethylmethacrylate-augmented pedicle screw fixation.

OBJECT: Instrumentation of the osteoporotic spine can be fraught with complications such as hardware failure. A cadaver study was performed to determine the biomechanical performance of polymethylmethacrylate (PMMA)-augmented pedicle screws. METHODS: Three osteoporotic human cadaveric specimens with a mean bone mineral density of 0.70 g/cm2 were used to evaluate the performance of a novel fenestrated bone tap in pedicle screw augmentation. On this device, tap threads serve a dual purpose in preventing backflow of cement toward neural elements while allowing for a custom form for subsequent screw placement. The tap was used to inject a mean volume of 3.7 ml PMMA/pedicle (range 2-8.0 ml PMMA/pedicle) followed by pedicle screw placement between L-5 and T-5, alternating between augmented and nonaugmented instrumentation. Axial pullout testing was then performed. RESULTS: Pedicle screw pullout strength was increased in both primary and salvage procedures by 119% (p = 0.001) and 162% (p = 0.01), respectively, after PMMA augmentation. Additionally, the injected cement volumes were divided into two groups, a low-cement group (< or = 2.8 ml/pedicle) and a high-cement group (> or = 5.5 ml/pedicle). Interestingly, the pullout strength did not significantly change with increased cement usage between the two groups (p > 0.05 for all comparisons). CONCLUSIONS: Polymethylmethacrylate-augmented pedicle screw fixation results in a significant increase in the axial pullout strength of augmented pedicle screws in both primary and revision procedures. This technique may be a valuable adjunct in cases in which bolstering of the screw-bone interface is necessary.

Minimally invasive percutaneous screw fixation of traumatic spondylolisthesis of the axis.

OBJECT Most cases of traumatic spondylolisthesis of the axis (hangman's fracture) can be treated nonoperatively with reduction and subsequent immobilization in a rigid cervical collar or halo. However, in some instances, operative management is necessary and can be accomplished by using either anterior or posterior fusion techniques. Because open posterior procedures can result in significant blood loss, pain, and limited cervical range of motion, other less invasive options for posterior fixation are needed. The authors describe a minimally invasive, navigation-guided technique for surgical treatment of Levine-Edwards (L-E) Type II hangman's fractures. METHODS For 5 patients with L-E Type II hangman's fracture requiring operative reduction and internal fixation, percutaneous screw fixation directed through the fracture site was performed. This technique was facilitated by use of intraoperative 3D fluoroscopy and neuronavigation. RESULTS Of the 5 patients, 2 were women, 3 were men, and age range was 46-67 years. No intraoperative or postoperative complications occurred. All patients wore a rigid cervical collar, and flexion-extension radiographs were obtained at 6 months. For all patients, dynamic imaging demonstrated a stable construct. CONCLUSIONS L-E type II hangman's fractures can be safely repaired by using percutaneous minimally invasive surgical techniques. This technique may be appropriate, depending on circumstances, for all L-E Type I and II hangman's fractures; however, the degree of associated ligament injury and disc disruption must be accounted for. Percutaneous fixation is not appropriate for L-E Type III fractures because of significant displacement and ligament and disc disruption. This report is meant to serve as a feasibility study and is not meant to show superiority of this procedure over other surgical options.

Primary central nervous system cytotoxic/suppressor T-cell lymphoma: report of a unique case and review of the literature.

Peripheral T-cell lymphoma primary to the central nervous system is a rare occurrence. The authors report a case of an 89-year-old woman who presented with a 3-month history of worsening confusion and recent onset of headache, nausea and vomiting, and upper limb tremors. Computed tomography and magnetic resonance imaging examinations demonstrated a 4.5-cm solitary brain mass in the right basal ganglia with compression along the ventricular system. No other lesion was found in the patient. Histologic and immunohistochemical studies of a stereotactic biopsy of the mass showed a T-cell lymphoproliferative lesion positive for CD3, CD8, CD57, and T-cell intracellular antigen 1 and negative for CD4, CD56, CD30, anaplastic lymphoma kinase, and CD20. A monoclonal T-cell receptor-gamma gene rearrangement was detected by polymerase chain reaction analysis of genomic DNA isolated from paraffin-embedded tumor tissue sections. These findings were consistent with peripheral T-cell lymphoma of cytotoxic/suppressor phenotype, resembling the phenotype of T-cell large granular cell leukemia. To the authors' best knowledge, this represents the first reported case of primary brain T-cell lymphoma with a cytotoxic/suppressor immunophenotype. A brief review of the literature of primary brain T-cell lymphoma is also presented.

Occipital condyle to cervical spine fixation in the pediatric population.

Fixation at the craniovertebral junction (CVJ) is necessary in a variety of pediatric clinical scenarios. Traditionally an occipital bone to cervical fusion is preformed, which requires a large amount of hardware to be placed on the occiput of a child. If a patient has previously undergone a posterior fossa decompression or requires a decompression at the time of the fusion procedure, it can be difficult to anchor a plate to the occipital bone. The authors propose a technique that can be used when faced with this difficult challenge by using the occipital condyle as a point of fixation for the construct. Adult cadaveric and a limited number of case studies have been published using occipital condyle (C-0) fixation. This work was adapted for the pediatric population. Between 2009 and 2012, 4 children underwent occipital condyle to axial or subaxial spine fixation. One patient had previously undergone posterior fossa surgery for tumor resection, and 1 required decompression at the time of operation. Two patients underwent preoperative deformity reduction using traction. One child had a Chiari malformation Type I. Each procedure was performed using polyaxial screw-rod constructs with intraoperative neuronavigation supplemented by a custom navigational drill guide. Smooth-shanked 3.5-mm polyaxial screws, ranging in length from 26 to 32 mm, were placed into the occipital condyles. All patients successfully underwent occipital condyle to cervical spine fixation. In 3 patients the construct extended from C-0 to C-2, and in 1 from C-0 to T-2. Patients with preoperative halo stabilization were placed in a cervical collar postoperatively. There were no new postoperative neurological deficits or vascular injuries. Each patient underwent postoperative CT, demonstrating excellent screw placement and evidence of solid fusion. Occipital condyle fixation is an effective option in pediatric patients requiring occipitocervical fusion for treatment of deformity and/or instability at the CVJ. The use of intraoperative neuronavigation allows for safe placement of screws into C-0, especially when faced with a challenging patient in whom fixation to the occipital bone is not possible or is less than ideal.

Percutaneous vertebroplasty for osteoporotic vertebral compression fractures in the nonagenarians: a prospective study evaluating pain reduction and new symptomatic fracture rate.

STUDY DESIGN: A prospective observational cohort study of consecutive osteoporotic vertebral compression fractures (VCFs) in ≥ 90-year-old patients evaluated at a multidisciplinary, university spine center. OBJECTIVE: Assess efficacy, safety, and new fracture occurrence after percutaneous vertebroplasty (PV) in a large uncontrolled cohort of ultra elderly VCF patients. SUMMARY OF BACKGROUND DATA: VCFs are associated with increased morbidity and mortality. Percutaneous injection of polymethylmethacryl-ate into the fractured vertebral body, vertebroplasty, has been extensively performed as an effective minimally-invasive treatment option for VCF patients. The patient sample included consecutive, osteoporotic patients with symptomatic VCFs electing to enter the study. METHODS: Baseline visual analogue scale rating, analgesic usage, duration of symptoms. Subsequent VAS ratings, analgesic utilization, and new fractures were assessed within 30 minutes after the procedure, at 2 weeks, 1 month, 3 months, 6 months, 1 year, and 2 years postprocedure. OUTCOME MEASURES: Visual Analogue Scale score, analgesic utilization, patient satisfaction, cement extravasation, and new fractures. RESULTS.: A total of 123 (74% female) underwent PV for 163 VCFs. Eleven patients did not complete final follow-up at 2 years due to death unrelated to the PV procedure. The mean VAS score was 7.6 at baseline and 3.1 at 30 minutes after the procedure, and 2.3, 1.2, 1.1, 0.9, 0.8, and 0.5 at 2 weeks, 1 month, 3 months, 6 months, 1 year, and 2 years, respectively. Improvement over time was statistically significant using repeated measures analysis of variance (P < 0.05). No complications were encountered during the follow-up intervals. Thirteen new fractures were observed (10.6%) at a mean 20.8 weeks (1-52 weeks) after PV with 6 new fractures (4.9%) involving an adjacent level in 5 patients (4.1%). CONCLUSION: Vertebroplasty for VCFs in the very elderly appears effective and safe without increased risk of adjacent level fracture.

Posterior occipitocervical (C0-3) fusion using polyaxial occipital condyle to cervical spine screw and rod fixation: a radiographic and cadaveric analysis.

Numerous conditions affect the occipitocervical junction requiring treatment with occipitocervical fixation. In this paper the authors present their technique of craniocervical fixation achieved with the cephalad extension of posterior C1-3 polyaxial screw and rods to polyaxial screws placed in the occipital condyles. They retrospectively analyzed occipital condyle morphology obtained from CT analyses of 40 patients with normal cervical spines, evaluated occipital condyle screw placement feasibility in 4 cadavers, and provided a case report of a 70-year-old woman with rheumatoid arthritis, basilar invagination, and atlantoaxial instability who was treated with this novel technique. Based on radiographic analysis of occipital condyle anatomy, they concluded that on average a 3.5-mm-diameter x 20- to 30-mm-long screw can be safely placed at an angle of 20-33 degrees from the sagittal plane. Overall, measuring the condylar heights (mean [+/- SD] 10.8 +/- 1.5 mm, range 8.1-15.0 mm), widths (mean 11.1 +/- 1.4 mm, range 8.5-14.2 mm), lengths (20.3 +/- 2.1 mm, range 15.4-24.6 mm), and angles (mean 32.8 +/- 5.2 degrees , range 20.2-45.8 degrees) by using CT studies is an accurate and precise method. This finding correlates with the results of prior anatomical studies of occipital condyles and is important in the planning of craniovertebral junction surgery.

Factors contributing to failure in endoscopic skull base defect repair.

BACKGROUND: Endoscopic repair of skull base (SB) defects is successful in over 90% of cases. Certain factors may contribute to failure of SB repair techniques or need for secondary repair. METHODS: Five-year retrospective review of endoscopic SB defect repairs performed by a single surgeon. RESULTS: Eighty-nine patients undergoing 110 procedures to repair 97 SB defects were evaluated. Etiology of defects included surgical/iatrogenic (64%), spontaneous (17%), traumatic (12%), congenital (6%), and idiopathic (1%). Defects occurred in the sella (41%), sphenoid sinus (18%), ethmoid roof (17%), olfactory cleft (16%), frontal sinus/recess (6%), and middle cranial fossa (2%). Sixty-three patients (71%) underwent primary SB defect repair and 26 patients underwent secondary repair (29%). In revision cases, mean number of prior repair attempts was 1.5 (range, 1-4). Factors potentially contributing to need for secondary SB defect repair included inability to localize SB defect (p =0 .008), development of new SB defect, prior sinus or SB surgery (p < 0.001), prior craniotomy (p < 0.001), prior radiation therapy (p = 0.002), and intracranial infection (p = 0.023). SB defects were successfully closed in 83 patients overall (93%), with success achieved in 97% of primary patients and 85% of secondary patients. Of failures, 3 patients required craniotomy for defect closure, 2 patients underwent permanent cerebrospinal fluid (CSF) diversion, and 1 patient has persistent CSF rhinorrhea. CONCLUSION: Although endoscopic repair of SB defect remains largely successful, certain factors should alert the surgeon to the potential for failure of repair or need for secondary SB defect repair.

Endoscopic repair of skull base defects presenting with pneumocephalus.

OBJECTIVE: Persistent pneumocephalus often indicates the presence of a skull base (SB) defect associated with one of the paranasal sinuses. Such defects require treatment to avoid sequelae. The study objective was to evaluate success in endoscopic closure of SB defects associated with pneumocephalus. DESIGN: Retrospective medical record review. SETTING: Tertiary care academic rhinology practice. METHODS: A 5-year retrospective review of patients presenting with pneumocephalus. Presenting symptoms, etiology of SB defects, radiologic findings, operative techniques, and follow-up were evaluated. MAIN OUTCOME MEASURES: Success of endoscopic SB defect repair in the setting of pneumocephalus was assessed. Factors potentially contributing to failure were evaluated in appropriate cases. RESULTS: Eleven patients with pneumocephalus from 14 SB defects underwent 17 endoscopic repairs. In 11 surgical procedures, active cerebrospinal fluid (CSF) leaks were identified, but in the remaining 6, pneumocephalus was present without CSF leak. Radiologic location of pneumocephalus ranged from extra-axial to diffuse within the brain parenchyma. SB defects were identified using fine-cut computed tomographic (CT) scans, CT cisternograms, and intrathecal fluorescein. Defects were located in the sphenoid, sella, ethmoid roof, and frontal sinus posterior table. Eight of 11 patients (72%) were managed with endoscopic repair alone. Factors potentially affecting failure included malignancy, previous radiation, intracranial infection, malnutrition, and Cushing disease. CONCLUSIONS: Endoscopic SB defect repair for pneumocephalus is largely successful. Localization of SB defects in these cases is often assisted by CT cisternography and intrathecal fluorescein.