Primary anterior lumbar interbody fusion, with and without posterior instrumentation: a 1,377-patient cohort from a multicenter spine registry.

BACKGROUND CONTEXT: Lumbar interbody instrumentation techniques are common and effective surgical options for a variety of lumbar degenerative pathologies. Anterior lumbar interbody fusion (ALIF) has become a versatile and powerful means of decompression, stabilization, and reconstruction. As an anterior only technique, the integrity of the posterior muscle and ligaments remain intact. Adding posterior instrumentation to ALIF is common and may confer benefits in terms of higher fusion rate but could contribute to adjacent segment degeneration due to additional rigidity. Large clinical studies comparing stand-alone ALIF with and without posterior supplementary fixation (ALIF+PSF) are lacking. PURPOSE: To compare rates of operative nonunion and adjacent segment disease (ASD) in ALIF with or without posterior instrumentation. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Adult patients (≥18 years old) who underwent primary ALIF for lumbar degenerative pathology between levels L4 to S1 over a 12-year period. Exclusion criteria included trauma, cancer, infection, supplemental decompression, noncontiguous fusions, prior lumbar fusions, and other interbody devices. OUTCOME MEASURES: Reoperation for nonunion and ASD compared between ALIF only and ALIF+PSF. METHODS: Reoperations were modeled as time-to-events where the follow-up time was defined as the difference between the primary ALIF procedure and the date of the outcome of interest. Crude cumulative reoperation probabilities were reported at 5-years follow-up. Multivariable Cox proportional hazard regression was used to evaluate risk of operative nonunion and for ASD adjusting for patient characteristics. RESULTS: The study consisted of 1,377 cases; 307 ALIF only and 1070 ALIF+PSF. Mean follow-up time was 5.6 years. The 5-year crude nonunion incidence was 2.4% for ALIF only and 0.5% for ALIF+PSF; after adjustment for covariates, a lower operative nonunion risk was observed for ALIF+PSF (HR=0.22, 95% CI=0.06-0.76). Of the patients who are deemed potentially suitable for ALIF alone, one would need to add posterior instrumentation in 53 patients to prevent one case of operative nonunion at a 5-year follow-up (number needed to treat). Five-year operative ASD incidence was 4.3% for ALIF only and 6.2% for ALIF+PSF; with adjustments, no difference was observed between the cohorts (HR=0.96, 95% CI=0.54-1.71). CONCLUSIONS: While the addition of posterior instrumentation in ALIFs is associated with lower risk of operative nonunion compared with ALIF alone, operative nonunion is rare in both techniques (<5%). Accordingly, surgeons should evaluate the added risks associated with the addition of posterior instrumentation and reserve the supplemental posterior fixation for patients that might be at higher risk for operative nonunion. Rates of operative ASD were not statistically higher with the addition of posterior instrumentation suggesting concern regarding future risk of ASD perhaps should not play a role in considering supplemental posterior instrumentation in ALIF.

Simultaneous cerebrospinal fluid and hematologic metastases in a high-grade ependymoma.

BACKGROUND: Ependymomas are relatively uncommon tumors that constitute about 7% of all primary intracranial neoplasms. Among these, high-grade ependymomas are locally aggressive and recur most commonly at the primary site following resection. Ependymomas are also known to be the one glial neoplasm that tends to frequently metastasize inside and outside the central nervous system (CNS) that complicates workup and management. Metastasis due to surgical manipulation is common and neurosurgeons should be well-versed in the most effective methods to remove these tumors in order to avoid such metastases. CASE DESCRIPTION: Here, we report a case of a 28-year-old female who initially presented with a parenchymal World Health Organization (WHO) grade III anaplastic ependymoma of the occipital lobe without metastasis. After multiple resections, the patient showed no evidence of disease recurrence for 2 years. During follow-up, new metastasis to the frontal lobe as well as to the lung were discovered 2 years after the initial surgery, without recurrence at the tumor's primary site. CONCLUSIONS: While uncommon, this case demonstrates the possibility for ependymomas to metastasize via cerebrospinal fluid to other locations within the CNS and hematologically to extraneural locations without recurring locally.

Surgical nuances of partial sacrectomy for chordoma.

BACKGROUND: Sacral chordomas are rare, slow growing, locally aggressive tumors. Unfortunately, aggressive surgical resection is often associated with increased neurological morbidity. METHODS: This technical note focuses on the utilization of partial sacrectomy for the resection of complex spinal chordomas. RESULTS: The case presented documents the potential range of postoperative morbidity seen in patients undergoing partial sacrectomy for chordomas. Despite iatrogenic morbidity and tumor recurrence, with the cooperation of medical and surgical spine specialists, majority of patients can achieve good long-term outcomes. CONCLUSIONS: Sacral chordomas are rare lesions and pose a therapeutic challenge for spinal surgeons and oncologists. En-bloc surgical resection (e.g., partial sacrectomy) is the treatment of choice for these lesions, and the cooperation between subspecialists can lead to good neurologic outcomes, particularly if gross total resection is achieved.

Surgical nuances of circumferential lumbar spondylectomy: A case report and short literature review.

BACKGROUND: Chordomas are uncommon malignant bone tumors that are often minimally symptomatic for several years. By the time they are diagnosed, these lesions are typically large, involve major neural, bony, and vascular structures, and are no longer readily resectable. This leads to a high recurrence rate. CASE DESCRIPTION: In this case report, we present a 67-year-old male with nonmechanical axial back pain, neurogenic claudication, and a large mass centered at the L3 level on magnetic resonance imaging consistent with a locally invasive chordoma. The patient underwent surgical resection that required a complete lumbar spondylectomy utilizing a three-stage approach, leading to incomplete tumor excision. The patient's residual postoperative symptoms included paresthesias/numbness in the right anterior thigh and a partial (4/5) right-sided foot drop. At the time of discharge, there were plans for future proton beam therapy. CONCLUSIONS: Because of their relative resistance to chemotherapeutic agents, the optimal surgical management of chordomas is gross total en-bloc excision. Unfortunately, this is rarely feasible.

Adult sacrococcygeal teratoma with coccygectomy: A case report with a review of the literature.

BACKGROUND: Saccrococcygeal teratomas (SCT) are derived from embryonic germ cell layers. They frequently present at the base of the coccyx within the pelvis. While these tumors are common in children, they are exceedingly rare in adults. In adults, a majority of these tumors are intrapelvic and associated with a low risk of malignant transformation. Therefore, this contributes to a good prognosis following resection of mostly benign lesions. CASE DESCRIPTION: An adult female with chronic pelvic pain presented with a sacral teratoma. She failed conservative treatment and underwent a coccygectomy with an en-bloc excision of the tumor. Microscopic histological analysis showed no evidence of immature or malignant elements, confirming the diagnosis of a mature, benign, cystic SCT. CONCLUSIONS: Mature SCTs in adults are rare malignant lesions. In this case, the patient was cured following primary surgical excision requiring en-bloc coccygectomy.

Adjuvant Stereotactic Radiosurgery and Radiation Therapy for the Treatment of Intracranial Chordomas.

Objective Chordomas are locally aggressive, highly recurrent tumors requiring adjuvant radiotherapy following resection for successful management. We retrospectively reviewed patients treated for intracranial chordomas with adjuvant stereotactic radiosurgery (SRS) and stereotactic radiation therapy (SRT). Methods A total of 57 patients underwent 83 treatments at the UCLA Medical Center between February 1990 and August 2011. Mean follow-up was 57.8 months. Mean tumor diameter was 3.36 cm. Overall, 8 and 34 patients received adjuvant SRS and SRT, and the mean maximal dose of radiation therapy was 1783.3 cGy and 6339 cGy, respectively. Results Overall rate of recurrence was 51.8%, and 1- and 5-year progression-free survival (PFS) was 88.2% and 35.2%, respectively. Gross total resection was achieved in 30.9% of patients. Adjuvant radiotherapy improved outcomes following subtotal resection (5-year PFS 62.5% versus 20.1%; p = 0.036). SRS and SRT produced comparable rates of tumor control (p = 0.28). Higher dose SRT (> 6,000 cGy) (p = 0.013) and younger age (< 45 years) (p = 0.03) was associated with improved rates of tumor control. Conclusion Adjuvant radiotherapy is critical following subtotal resection of intracranial chordomas. Adjuvant SRT and SRS were safe and improved PFS following subtotal resection. Higher total doses of SRT and younger patient age were associated with improved rates of tumor control.

Predictors of recurrence following resection of intracranial chordomas.

Management of intracranial chordomas remains challenging, despite improvements in microsurgical techniques and radiotherapy. Here, we analyzed the prognostic factors associated with improved rates of tumor control in patients with intracranial chordomas, who received either gross (GTR) or subtotal resections (STR). A retrospective review was performed to identify all patients who were undergoing resection of their intracranial chordomas at the Ronald Reagan University of California Los Angeles Medical Center from 1990 to 2011. In total, 57 patients undergoing 81 resections were included. There were 24 females and 33 males with a mean age of 44.6 years, and the mean tumor diameter was 3.36 cm. The extent of resection was not associated with recurrence. For all 81 operations, the 1 and 5 year progression free survival (PFS) was 87.5 and 40.4%, and 88.0 and 33.6% for STR and GTR, respectively (p=0.90). Adjuvant radiotherapy was associated with improved rates of PFS (hazard ratio [HR] 0.20; p=0.009). Additionally, age >45 years (HR 5.88; p=0.01) and the presence of visual deficits (HR 7.59; p=0.03) were associated with worse rates of tumor control. Tumor size, sex, tumor histology, and recurrent tumors were not predictors of recurrence. Younger age, lack of visual symptoms on presentation and adjuvant radiotherapy were associated with improved rates of tumor control following surgery. However, GTR and STR produced comparable rates of tumor control. The surgical management of intracranial chordomas should take a conservative approach, with the aim of maximal but safe cytoreductive resection with adjuvant radiation therapy, and a major focus on quality of life.

Intramedullary abscess of the spinal cord in the setting of patent foramen ovale.

BACKGROUND: Intramedullary abscess of the spinal cord is a rare entity, especially in the setting of an intracardiac shunt, which, to our knowledge, has not been described in the literature. Here we present a case of an intramedullary spinal cord abscess in a patient with a patent foramen ovale. METHODS: The article includes a chart review and description of a clinical case presentation. RESULTS: A 59-year-old man was admitted with rapidly progressive quadriparesis. Magnetic resonance imaging of the cervical spine demonstrated a large intramedullary mass extending from the level of C3 to C7. The patient was taken to the operating room for biopsy and surgical evacuation of the mass. Intraoperative pathology was consistent with abscess, and subsequent cultures grew Streptococcus viridans. On further workup, the patient was found to have a patent foramen ovale with right-to-left flow. Postoperatively, the strength improved significantly in all extremities with residual weakness. CONCLUSION: This is the first published case of an intramedullary spinal cord abscess in the setting of an intracardiac right-to-left shunt. Although intramedullary spinal cord abscess is rare, there are certain predisposing conditions that increase the risk of its occurrence.

Symptomatic vertebral artery compression by the rod of a C1-C2 posterior fusion construct: case report and review of the literature.

STUDY DESIGN: Case report. OBJECTIVE: To report a rare complication of atlantoaxial fusion. SUMMARY OF BACKGROUND DATA: Vertebral artery injury is a serious complication of screw-based atlantoaxial fusion. To our knowledge, injury to the vertebral artery has only been described as a result of screw placement. We describe the first case of atlantoaxial fixation complicated by symptomatic and reversible external compression of the vertebral artery by the rod in a Harms construct. METHODS: Medical records and imaging reports were reviewed. RESULTS: A neurologically intact 84-year-old woman presented after a ground-level fall. Imaging revealed a nondisplaced type II odontoid fracture associated with a C1 ring fracture. She underwent a minimally invasive Harms atlantoaxial fusion. After surgery, she developed fluctuating level of consciousness in the setting of an otherwise normal neurologic and metabolic workup. A computed tomographic angiogram was obtained and showed good screw placement except for compression of the right vertebral artery from the right transfixing rod causing 75% luminal narrowing. She underwent a revision with rod shortening, and after surgery, improved neurologically, without any further episodes of altered mental status. CONCLUSION: In atlantoaxial fusion, the incidence of vertebral artery compression by the rod component of fusion construct may be underreported because it is difficult to detect with noncontrast computed tomography without computed tomographic angiography, which is not routinely obtained unless there is a high suspicion for vascular injury. We recommend inserting the rods with the cut (sharp) end pointing inferiorly, to avoid lacerating the vertebral artery. A vertebral artery compression from the rod in the absence of screw violation of the foramen transversarium should be considered in a patient with altered mental status after atlantoaxial fusion.

Evaluation of intracranial cerebrospinal fluid cytology in staging pediatric medulloblastomas, supratentorial primitive neuroectodermal tumors, and ependymomas.

OBJECT: The objective of this study was to determine the role of intracranial CSF examination in detecting true cases of early tumor dissemination. Cerebrospinal fluid dissemination is an ominous feature of pediatric brain tumors, occurring in as many as 30% of medulloblastomas, 25% of supratentorial primitive neuroectodermal tumors (PNETs), and 5% of ependymomas at diagnosis. Detecting early dissemination is important for determining both treatment and prognosis. Dissemination can be detected by evaluating imaging of the full neuraxis and by examining CSF cytology. Neuraxis MR imaging and lumbar CSF cytology evaluation are widely accepted methods for determining dissemination. However, the value of examining intracranial CSF cytology in detecting early dissemination is uncertain. METHODS: Under an institutional review board-approved protocol, medical records, pathology reports, and radiology reports for 150 patients who had undergone resection of brain tumors (88 with medulloblastomas, 21 with supratentorial PNETs, and 41 with ependymomas) and who had been evaluated using neuraxis MR imaging studies in the last 15 years were retrospectively reviewed. Radiology results were compared with the CSF cytology results and long-term disease outcomes. RESULTS: Between lumbar and intracranial CSF cytology results, 7 of 40 were discordant: in 2 intracranial CSF was negative and lumbar CSF was positive, and in 5 the reverse was true. The discordance percentage was 18%, with a kappa statistic of 0.36. Between MR imaging and lumbar CSF cytology results, 11 of 65 were discordant: in 9 the lumbar CSF was negative and MR imaging was positive, and in 2 the reverse was true. The discordance percentage is 17%, with a kappa statistic of 0.27. Between MR imaging and intracranial CSF cytology results, 8 of 52 were discordant: in 3 intracranial CSF was negative and MR imaging was positive, and in 5 the reverse was true. The discordance rate was 15%, with a kappa statistic of 0.41. Patients with positive and negative results on perioperative neuraxis MR imaging studies had a median survival of 26.8 and 33.1 months, respectively (p = 0.02). Patients with positive and negative results on perioperative lumbar CSF cytology had a median survival of 20.1 and 31.4 months, respectively (p = 0.11). Patients with positive and negative results on intracranial CSF cytology had a median survival of 31 and 31.4 months, respectively (p = 0.84). CONCLUSIONS: Discordance exists between the results of neuraxis MR imaging and lumbar and intracranial CSF cytology in perioperative detection of tumor dissemination for pediatric medulloblastoma, supratentorial PNETs, and ependymoma. In 1 case in this series, perioperative dissemination was detected by intracranial CSF cytology, but not by lumbar CSF cytology or neuraxis MR imaging. Isolated intracranial CSF cytology positivity may represent an earlier stage of disseminated disease. Complementary use of perioperative neuraxis MR imaging and lumbar and intracranial CSF cytology can reduce the incidence of missed diagnoses of dissemination. Survival analysis revealed that perioperative neuraxis MR imaging findings are correlated with survival, whereas perioperative lumbar and intracranial CSF cytology findings are not.

Survival in lymph node negative adenocarcinoma of the esophagus after R0 resection with and without neoadjuvant therapy: evidence for downstaging of N status.

BACKGROUND: After esophagectomy, many patients who received neoadjuvant therapy have no evidence of lymph node involvement (N0 disease). Whether lymph nodes were initially involved and eradicated by the neoadjuvant therapy (down-staged) or if the nodes were never involved is a subject of debate. To address this issue, we compared clinical outcomes in N0 patients treated with neoadjuvant therapy with outcomes in patients treated with surgery alone. STUDY DESIGN: We reviewed records of 100 consecutive patients who underwent R0 esophagectomy for adenocarcinoma with pathologic N0 status. Seventy-five patients were treated by operation alone and 25 received neoadjuvant therapy. Tumor characteristics including length, depth, lymphovascular invasion, and degree of differentiation were compared and longterm survival was assessed by Kaplan-Meier analysis at a median of 46 months (interquartile range 26 to 77 months). RESULTS: Tumor characteristics were similar between groups. Recurrence was more common in patients who received neoadjuvant therapy compared with those treated with surgery alone (10 of 25 versus 10 of 75, p=0.0063). Patients with N0 disease after neoadjuvant therapy had a significantly worse survival than patients treated by surgery alone (49% versus 85%, p=0.005). CONCLUSIONS: Although neoadjuvant therapy may eradicate lymph node metastases, it does not result in the same outcomes as those achieved in patients with N0 disease treated with surgery alone. The poor clinical outcomes observed in N0 patients after neoadjuvant therapy suggest that they initially had node involvement and were downstaged by eradication of lymph node disease.