Abstracts of the 2013 Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Phoenix, Arizona • March 6–9, 2013
Lissa Peeling, Evan Frangou, Stephen Hentschel, Ziya L. Gokaslan, and Daryl R. Fourney
The treatment of complex thoracolumbar disorders occasionally requires combined anterior and posterior approaches. Traditionally, these are either sequentially staged to occur during the same anesthesia procedure or alternatively performed on separate days. A less common option is the simultaneous anterior-posterior approach. The authors discuss the rationale for this approach in selected cases and illustrate a number of modifications to previous descriptions of the procedure. By slightly altering the incision, the risk of wound breakdown and infection has been reduced. The use of newly available positioning devices has allowed easy incorporation of fluoroscopy to guide the placement of spinal instrumentation. The authors have also expanded the use of the approach beyond the original oncological indications to include trauma and infection.
Daryl R. Fourney, Laurence D. Rhines, Stephen J. Hentschel, John M. Skibber, Jean-Paul Wolinsky, Kristin L. Weber, Dima Suki, Gary L. Gallia, Ira Garonzik, and Ziya L. Gokaslan
En bloc resection with adequate margins is associated with the highest probability of long-term tumor control or cure in most cases of primary sacral malignancies. The authors present their experience with a systematic approach to these lesions. They provide a novel classification of surgical techniques based on the level of nerve root sacrifice and evaluate the functional and oncological outcomes.
Seventy-eight consecutive patients underwent 94 resections of sacral neoplasms at The University of Texas M. D. Anderson Cancer Center in Houston between August 1993 and June 2002. The records of 29 consecutive patients who underwent en bloc resection of primary sacral tumors were retrospectively reviewed. The median follow-up period was 55 months (range 1–103 months). Chordoma was the most frequent tumor type (16 cases). Midline sacral amputation was performed in 25 patients (eight low, four middle, seven high, and five total sacrectomies; one hemicorporectomy). Lateral sacrectomy was undertaken in four patients (two unilateral excisions of the sacroiliac joint and two hemisacrectomies). The surgical margins were wide in 19 cases, marginal in nine, and contaminated in one. The type of sacrectomy correlated with characteristic outcomes with respect to bladder, bowel, and ambulatory functions. Duration of hospital stay was related to the extent of sacrectomy (p = 0.003, Wilcoxon signed-rank test). The median Kaplan—Meier disease-free survival for patients with chordoma was 68 months (95% confidence interval 46–90 months).
Classification of en bloc sacral resection techniques by the level of nerve root transection is useful in predicting postoperative function and the potential for morbidity. Adequate surgical margins should not be compromised to preserve function when they are necessary to affect tumor control.
Case report and description of operative technique
Laurence D. Rhines, Daryl R. Fourney, Abdolreza Siadati, Ian Suk, and Ziya L. Gokaslan
✓ Chordomas are locally aggressive neoplasms with an extremely high propensity to recur locally following resection, despite adjuvant therapy. This biological behavior has led most authors to conclude that en bloc resection provides the best chance for the patient's prolonged disease-free survival and possible cure.
The authors present a case of an extensive upper cervical chordoma treated by en bloc resection, reconstruction, and long-segment stabilization. Total spondylectomy of C2–4 with sacrifice of the right C2–4 nerve roots and a segment of the right vertebral artery was performed. The inherent anatomical complexities of en bloc resection in the upper cervical spine are discussed. To the authors' knowledge, this represents the first report of an en bloc resection for multilevel cervical chordoma.
Use of “MAPS” for determining the optimal surgical approach to metastatic disease of the thoracolumbar spine: anterior, posterior, or combined
Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004
Daryl R. Fourney and Ziya L. Gokaslan
✓ The surgical treatment of thoracolumbar metastases is controversial, and various approaches have been described. No single approach, however, is always applicable, and the optimal surgical strategy for any individual is determined by several interrelated factors. The authors have grouped these factors into four preoperative planning considerations that form the mnemonic “MAPS”: 1) method of resection; 2) anatomy of spinal disease; 3) patient's level of fitness; and 4) stabilization. The choice of approach is also considered in light of the goals of surgery, including the relief of pain, neurological palliation, spinal stabilization, and oncological control.
Case report and review of the literature
Daryl R. Fourney, Abdolreza Siadati, Janet M. Bruner, Ziya L. Gokaslan, and Laurence D. Rhines
✓ Several rare histological variants of ependymoma have been described. The authors report on a patient in whom cervical spinal cord astrocytoma was originally diagnosed after evaluation of a limited biopsy specimen. More abundant tissue obtained during gross-total resection included areas of well-differentiated ependymoma. The histological features of the tumor were extremely unusual, with a major component of pleomorphic giant cells. Its histological, immunohistochemical, and electron microscopic features, however, were consistent with ependymoma. Only two cases of terminal filum and two of supratentorial giant cell variant of ependymoma have been reported. To the authors' knowledge, this represents the first case of giant cell ependymoma of the spinal cord. The clinical significance is the potential for misdiagnosis with anaplastic (gemistocytic) astrocytoma, especially in cases in whom limited biopsy samples have been obtained.
Daryl R. Fourney and Ziya L. Gokaslan
Sacral chordomas are relatively rare, locally invasive, malignant neoplasms. Although metastasis is infrequent at presentation, the prognosis for patients with chordoma of the sacrum is reported to be poor and attributable in most cases to intralesional resection. The value of adjuvant treatment is uncertain, and resection remains the primary mode of treatment. Chordomas are difficult to excise completely, but recent improvements in imaging and surgical techniques have allowed surgeons to perform more frequently en bloc sacral resections with wide surgical margins. The technical challenges of such operations, and the functional costs for the patient (with respect to anorectal and urogenital dysfunction) are significantly increased when the tumor involves high sacral levels. The authors review the clinical presentation and natural history of sacral chordoma and discuss the current treatment techniques and outcomes.
Daryl R. Fourney, Julie E. York, Zvi R. Cohen, Dima Suki, Laurence D. Rhines, and Ziya L. Gokaslan
Object. The treatment of atlantoaxial spinal metastases is complicated by the region's unique biomechanical and anatomical characteristics. Patients most frequently present with pain secondary to instability; neurological deficits are rare. Recently, some authors have performed anterior approaches (transoral or extraoral) for resection of upper cervical metastases. The authors review their experience with a surgical strategy that emphasizes posterior stabilization of the spine and avoidance of poorly tolerated external orthoses such as the rigid cervical collar or halo vest.
Methods. The authors performed a retrospective review of 19 consecutively treated patients with C-1 or C-2 metastases who underwent surgery at The University of Texas M. D. Anderson Cancer Center between 1994 and 2001.
Visual analog pain scores were reduced at 1 and 3 months (p < 0.005, Wilcoxon signed-rank test); however, evaluation of pain at 6 months and 1 year was limited by the remaining number of surviving patients. Analgesic medication consumption was unchanged. There were no cases of neurological decline or sudden death secondary to residual or recurrent atlantoaxial disease during the follow-up period. One patient underwent revision of hardware at 11 months. The mean follow-up period was 8 months (range 1–32 months). Median survival determined by Kaplan—Meier analysis was 6.1 months (95% confidence interval 2.99–9.21).
Conclusions. Occipitocervical stabilization provided durable pain relief and preservation of ambulatory status over the remaining life span of patients. Because of the palliative goals of surgery, the authors have not found an indication for anterior-approach tumor resection in these patients. Successful stabilization obviates the need for an external orthosis.
Daryl R. Fourney, Donald F. Schomer, Remi Nader, Jennifer Chlan-Fourney, Dima Suki, Kamran Ahrar, Laurence D. Rhines, and Ziya L. Gokaslan
Object. The current North American experience with minimally invasive vertebro- and kyphoplasty is largely limited to the treatment of benign osteoporotic compression fractures. The objective of this study was to assess the safety and efficacy of these procedures for painful vertebral body (VB) fractures in cancer patients.
Methods. The authors reviewed a consecutive group of cancer patients (21 with myeloma and 35 with other primary malignancies) undergoing vertebro- and kyphoplasty at their institution. Ninety-seven (65 vertebro- and 32 kyphoplasty) procedures were performed in 56 patients during 58 treatment sessions. The mean patient age was 62 years (± 13 years [standard deviation]) and the median duration of symptoms was 3.2 months. All patients suffered intractable spinal pain secondary to VB fractures.
Patients noted marked or complete pain relief after 49 procedures (84%), and no change after five procedures (9%); early postoperative Visual Analog Scale (VAS) pain scores were unavailable in four patients (7%). No patient was worse after treatment. Reductions in VAS pain scores remained significant up to 1 year (p = 0.02, Wilcoxon signed-rank test). Analgesic consumption was reduced at 1 month (p = 0.03, Wilcoxon signed-rank test). Median follow-up length was 4.5 months (range 1 day–19.7 months). Asymptomatic cement leakage occurred during vertebroplasty at six (9.2%) of 65 levels; no cement extravasation was seen during kyphoplasty. There were no deaths or complications related to the procedures. The mean percentage of restored VB height by kyphoplasty was 42 ± 21%.
Conclusions. Percutaneous vertebro- and kyphoplasty provided significant pain relief in a high percentage of patients, and this appeared durable over time. The absence of cement leakage—related complications may reflect the use of 1) high-viscosity cement; 2) kyphoplasty in selected cases; and 3) relatively small 3volume injection. Precise indications for these techniques are evolving; however, they are safe and feasible in well-selected patients with refractory spinal pain due to myeloma bone disease or metastases.
Daryl R. Fourney and Ziya L. Gokaslan
In addition to tumor resection, a major goal of spine surgery involving tumors is the preservation or achievement of spinal stability. The criteria defining stability, originally developed for use in trauma, are not directly applicable in the setting of neoplasia. The authors discuss the most common patterns of tumor-related instability and deformity at all levels of the spinal column and review the surgical options for treatment.