Transfacet and Transpedicular Posterior Approaches to Thoracic Disc Herniations: Consecutive Case Series of 24 Patients.

OBJECTIVE: Various approaches are advocated for symptomatic thoracic disc herniation (TDH). The aim of this series is to demonstrate the feasibility, safety, and results of posterior transfacet or transpedicular approaches for excision of all types of extradural TDH. We report a consecutive series of patients undergoing posterior approach surgery for TDH. METHODS: Twenty-four patients (17 women, 7 men) underwent surgery at 25 disc levels. Mean age was 56.3 years (range, 23-79 years). A posterior transfacet or transpedicular approach was used. Patients presented with myelopathy (n = 21, 88%), radiculopathy (n = 8, 33%), sphincter dysfunction (n = 16, 67%), and axial back pain (n = 10, 43%). Preoperative imaging revealed 7 (30%) central, 14 (61%) calcified, and 10 (43%) large disc herniations. The mean follow-up period was 6.0 months (range, 2-36 months). RESULTS: Eighteen patients underwent unilateral approach surgery (5 transfacet and 13 transfacet plus transpedicular), and 7 patients required bilateral approach laminectomy for unilateral (n = 4) or bilateral (n = 3) discectomy. One patient required unplanned reoperation for resection of residual disc. Average operative time was 95 minutes (range, 40-175 minutes). Mean hospital stay was 4.9 days (range, 2-35 days). There were no major complications. Postoperative Frankel scores were maintained or improved in all patients at last review. CONCLUSIONS: TDH including large central calcified discs can be safely removed through posterior transfacet or transpedicular approaches with reduced morbidity in comparison with more invasive anterior approaches. Careful microsurgical technique and use of specialized instruments are important for successful excision of TDH from a posterior approach.

Comparative analysis of isocentric 3-dimensional C-arm fluoroscopy and biplanar fluoroscopy for anterior screw fixation in odontoid fractures.

STUDY DESIGN: Retrospective clinical study. OBJECTIVE: To compare long-term radiographic and clinical outcomes of patients undergoing anterior odontoid screw placement using traditional biplanar fluoroscopy or isocentric 3-dimensional C-arm (iso-C) fluoroscopy-assisted techniques. SUMMARY OF BACKGROUND DATA: Anterior screw fixation of odontoid fractures preserves motion at the C1-C2 joint, but accurate screw positioning is essential for successful outcomes. Biplanar fluoroscopy image guidance is most often used; however, iso-C imaging improves the ease and accuracy of screw placement with less radiation exposure. METHODS: Fifty-one patients underwent anterior odontoid screw fixation for type II (48 patients) and rostral type III fractures (3 patients). Procedures were guided by biplanar fluoroscopy in 25 (49%) patients, and with iso-C assistance in 26 (51%). Length of surgery, complications, and clinical outcomes based on the Smiley-Webster score were evaluated. Computed tomography confirmed adequate screw placement. Follow-up ranged from 3 to 9 months. RESULTS: At 3-month follow-up, screw position and fusion across the fracture were evident in 87% of the cases treated with biplanar fluoroscopy and in 100% treated by iso-C. The average outcome score in the iso-C group was superior to that of the biplanar group (1.08 vs. 1.33, respectively), although not statistically significant. At last follow-up, the rate of successful fusion was 88% in the biplanar group and 95% in the iso-C group. Length of surgery was significantly lower in the iso-C group compared with the biplanar group (P=0.05). The significantly longer preparation time in the iso-C group (P=0.04) accounted for no overall difference in total operating room occupancy time between the 2 groups. CONCLUSIONS: Iso-C significantly decreased surgical time. At last follow-up iso-C assistance was associated with improved rates of radiographic fusion with comparable outcome and complication profiles. This series represents the largest cohort of patients treated with intraoperative real-time navigation assistance for odontoid fractures.

A simple and quantitative method to predict symptomatic vasospasm after subarachnoid hemorrhage based on computed tomography: beyond the Fisher scale.

BACKGROUND: Although the Fisher scale is commonly used to grade vasospasm risk in aneurysmal subarachnoid hemorrhage (aSAH) patients, it fails to account for increasing subarachnoid hemorrhage (SAH) thickness. OBJECTIVE: We developed a simple quantitative scale based on maximal SAH thickness and compared its reproducibility and ability to predict symptomatic vasospasm against the Fisher scale. METHODS: The incidence of radiographic and symptomatic vasospasm among 250 aSAH patients treated at our institution was investigated. Admission head computed tomography scans were graded according to the Fisher scale and the proposed scale, which assigns a score from 1 to 5 based on a single measurement of maximum SAH thickness. We calculated vasospasm risk per grade for the Fisher scale and the proposed scale, and compared inter- and intraobserver variability for both scales. RESULTS: Forty-five patients (20.6%) developed symptomatic vasospasm. On the proposed scale, grade 5 patients were at highest risk, with an odds ratio for symptomatic vasospasm of 11 (95% confidence interval [CI] 2.27-53.37). Odds ratios for proposed grades 4 and 3 were 4.63 (95% CI 1.10-19.59) and 3.04 (95% CI 0.85-10.90), respectively. The odds ratio for Fisher grade 3 was 3.3 (0.96-11.30). Mean inter- and intraobserver agreement was greater for the proposed scale in comparison with the Fisher scale (κ0.65 and κ0.81 vs κ0.51 and κ0.35, respectively). CONCLUSION: The new scale accounted for increasing SAH thickness and was superior to the Fisher scale in inter- and intraobserver agreement and in predicting symptomatic vasospasm, particularly among the highest-risk patients.

Multimodality treatment of conus medullaris arteriovenous malformations: 2 decades of experience with combined endovascular and microsurgical treatments.

BACKGROUND: Conus medullaris arteriovenous malformations (AVMs) are rare, challenging spinal vascular lesions that cause progressive debilitating myeloradiculopathy. Only sporadic reports of conus AVMs have been published. OBJECTIVE: To better define the presentation, prognosis, and optimal treatment of these lesions, we present the first case series of conus AVMs, reflecting over 2 decades of experience with a multimodality endovascular and surgical approach. METHODS: We retrospectively reviewed the charts of 16 patients with a conus AVM evaluated at our institution from 1989 to 2010. For each patient, the following clinical data were collected: age, sex, symptoms, angiographic findings, type of treatment, complications, degree of angiographic obliteration, recurrence at follow-up, and need for re-treatment. Ambulatory status, Frankel Grade, motor function, and bladder/bowel function were assessed before treatment, at discharge, and at last follow-up. RESULTS: All 16 patients were treated. Eight (50%) patients underwent embolization followed by microsurgical resection, and 8 (50%) underwent microsurgical resection only. The rate of complete angiographic obliteration was 88%. At last follow-up (mean, 70 months), 43% of patients neurologically improved, 43% were stable, and 14% worsened in comparison with before treatment. During follow-up, 3 recurrences were detected, including the only 2 instances of long-term neurological decline. In the absence of recurrence, all patients ambulatory before treatment remained ambulatory at follow-up, whereas 75% of the initially nonambulatory patients regained the ability to walk. CONCLUSION: Although conus AVMs are challenging to treat, excellent long-term outcomes are possible with a multimodality approach. Recurrence is associated with long-term neurological decline and calls for close follow-up.

Survival and functional outcome after surgical resection of intramedullary spinal cord metastases.

OBJECTIVE: Intramedullary spinal cord metastasis (ISCM) is a rare manifestation of systemic cancer and data about the optimal management of these lesions are lacking. To clarify the role of surgery, we investigated survival and neurological outcomes after surgical resection of ISCMs. METHODS: Between 2003 and 2010, we surgically treated 10 ISCMs in 9 patients. For each patient, we retrospectively collected the following data: demographic variables, history of prior cancer, site of primary cancer, extent of cancer on presentation, degree of resection, preoperative and postoperative spinal cord impairment (American Spinal Injury Association [ASIA] grade), and postoperative survival. We investigated the relationship between these variables, overall survival, and preservation of function. RESULTS: Eight ISCMs were treated with gross total resection and two were treated with subtotal resection. Overall postoperative survival was 6.4 ± 9.4 months (mean ± standard deviation), with one patient still alive at last follow-up. Patients with a diagnosis of melanoma had higher mean survival than those with nonmelanoma histology (20.5 ± 13.4 vs. 2.4 ± 1.7 months, P < 0.01). Degree of resection, number of organ systems affected, ambulatory status, and ASIA grade pre operatively or postoperatively, were not significantly associated with survival. Of the nine patients, seven (78%) demonstrated no change in ASIA grade postoperatively, one (11%) improved, and one patient (11%) deteriorated. All patients who were ambulatory preoperatively remained ambulatory postoperatively and at last follow-up. CONCLUSIONS: Although ISCM is associated with poor prognosis, survival appears to be greater in patients with melanoma. Surgical resection does not appear to significantly lengthen survival but may be indicated to preserve ambulatory status in symptomatic patients.

Orbitozygomatic resection for hypothalamic hamartoma and epilepsy: patient selection and outcome.

PURPOSE: This study aims to examine the outcomes of ten patients after orbitozygomatic (OZ) pterional surgery in cases of refractory epilepsy caused by hypothalamic hamartomas (HH). METHODS: Ten patients with HH and treatment-resistant epilepsy (mean age 18.3 years, range 0.7 to 42.7) underwent HH resection with an OZ approach (n = 8) or an OZ approach combined with a transventricular endoscopic approach (n = 2). Follow-up for the patients ranged from 0.5 to 6.2 years (mean 3.1). Outcomes were prospectively monitored with the use of a proprietary database. RESULTS: Four patients (40%) are seizure-free, and four (40%) have had greater than 50% reduction in seizures. One patient had no significant change in seizure frequency, and one patient died unexpectedly 2.8 years after surgery. Six patients had total or near-total HH resection (98-100% of HH lesion volume). Of these, four of six (66%) were seizure-free, and two had at least greater than 50% reduction in seizures. Residual complications include diabetes insipidus (n = 1), poikilothermia (n = 1), visual field deficit (n = 1), and hemiparesis (n = 1). Eight families (80%) reported improved quality of life. CONCLUSIONS: Patients with treatment-resistant epilepsy and tumors with an inferior or horizontal plane of attachment to the hypothalamus should continue to be approached from below. Those with both intrahypothalamic and parahypothalamic components may require approaches from above and below, either simultaneously or staged. For appropriately selected patients, the success of controlling seizures with an OZ is comparable to results utilizing transcallosal or transventricular approaches. The likelihood of controlling seizures appears to correlate with extent of resection.

Neuroblastoma-like schwannoma of lumbar spinal nerve root.

Neuroblastoma-like schwannoma is a rare nerve sheath tumor with histological features resembling a neuroblastoma. A comprehensive literature review identified only 10 previous case reports of this condition. The authors present the first reported case of a neuroblastoma-like schwannoma at a spinal nerve root. The patient, a 61-year-old woman, presented with severe pain in the right lower extremity that failed to resolve after conservative management. Magnetic resonance imaging revealed an intradural enhancing lesion extending out of the right neural foramen at L1-2. A right L1-2 hemilaminectomy and facetectomy with gross-total resection of the tumor was performed without complications. Neuroblastoma-like schwannoma was diagnosed based on histopathological examination of the biopsied tumor specimen. A postoperative course of serial examination and imaging was chosen based on a suspected benign postoperative course as in the case of a completely resected schwannoma. The authors present the novel case of neuroblastoma-like schwannoma at a lumbar spinal nerve root and describe the distinguishing pathological features of this rare lesion.

Primary spinal intramedullary adrenal cortical adenoma associated with spinal dysraphism: case report.

OBJECTIVE: The authors report a primary spinal intramedullary adrenal cortical adenoma in a patient with spinal dysraphism presenting with bilateral leg pain and urinary frequency. METHODS: Magnetic resonance imaging, L2 laminectomy with resection of mass, and pathological and immunohistochemical analysis of resected mass revealed the diagnosis. RESULTS: Microscopic and immunohistochemical findings confirmed the diagnosis as a primary intramedullary tumor of adrenal cortical origin. CONCLUSION: The occurrence of a primary adrenal tumor in the spinal cord is rare and difficult to explain based on our understanding of embryology. A review of the relevant literature and discussion of the pathophysiology and clinical implications is provided.