The authors present 2 cases involving patients who presented with myelopathy. Magnetic resonance imaging of the cervical spine showed spinal cord signal changes on T2-weighted images without any spinal cord compression. Flexion-extension plain radiographs of the spine showed no instability. Dynamic MR imaging of the cervical spine, however, showed spinal cord compression on extension. Compression of the spinal cord was caused by dynamic anulus bulging and ligamentum flavum buckling. This report emphasizes the need for dynamic MR imaging of the cervical spine for evaluating spinal cord changes on neutral position MR imaging before further workup for other causes such as demyelinating disease.
Kern H. Guppy, Mark Hawk, Indro Chakrabarti and Amit Banerjee
Kern H. Guppy, Indro Chakrabarti and Amit Banerjee
Imaging guidance using intraoperative CT (O-arm surgical imaging system) combined with a navigation system has been shown to increase accuracy in the placement of spinal instrumentation. The authors describe 4 complex upper cervical spine cases in which the O-arm combined with the StealthStation surgical navigation system was used to accurately place occipital screws, C-1 screws anteriorly and posteriorly, C-2 lateral mass screws, and pedicle screws in C-6. This combination was also used to navigate through complex bony anatomy altered by tumor growth and bony overgrowth. The 4 cases presented are: 1) a developmental deformity case in which the C-1 lateral mass was in the center of the cervical canal causing cord compression; 2) a case of odontoid compression of the spinal cord requiring an odontoidectomy in a patient with cerebral palsy; 3) a case of an en bloc resection of a C2–3 chordoma with instrumentation from the occiput to C-6 and placement of C-1 lateral mass screws anteriorly and posteriorly; and 4) a case of repeat surgery for a non-union at C1–2 with distortion of the anatomy and overgrowth of the bony structure at C-2.
Indro Chakrabarti, Arun P. Amar, William Couldwell and Martin H. Weiss
Object. The authors report on a cohort of patients with craniopharyngioma treated principally through transnasal (TN) resection and followed up for a minimum of 5 years. More specifically, they evaluate the role of the TN approach in the management of craniopharyngioma.
Methods. Between 1984 and 1994, 68 patients underwent TN resection of craniopharyngiomas at the University of Southern California. The tumor was at least partially cystic in 88% of cases. Four tumors were purely intrasellar, 53 had intra- and suprasellar components, and 11 were exclusively suprasellar. During the same period, 18 patients underwent transcranial (TC) resection of purely suprasellar craniopharyngiomas. Long-term neurological, visual, and endocrine outcomes were reviewed for all patients.
In 61 (90%) of 68 patients in the TN group, total resection was achieved, according to 3-month postoperative magnetic resonance images, although four patients suffered a recurrence. Three (43%) of the seven tumors that had been partially resected were enlarged on serial imaging. Fifty-four (87%) of 62 patients with preoperative visual loss experienced improvement in one or both eyes, but two patients (3%) with exclusively suprasellar tumors experienced postoperative visual worsening in one or both eyes. New instances of postoperative endocrinopathy (that is, not present preoperatively) occurred as follows: hypogonadism (eight of 22 cases), growth hormone (GH) deficiency (four of 18 cases), hypothyroidism (11 of 49 cases), hypocortisolemia (nine of 52 cases), and diabetes insipidus (DI; four of 61 cases). One case each of hypocortisolemia and hypothyroidism resolved after surgery. Hyperphagia occurred in 27 (40%) of 68 patients. One patient had short-term memory loss. Postoperative complications included one case of cerebrospinal fluid leak.
Among the 18 patients in the TC group, 11 had complete resections. In one case (9%) the tumors recurred. Three (43%) of the seven subtotally resected tumors grew during the follow-up interval. Vision improved in 11 (61%) of 18 cases and worsened in three (17%) as a result of surgery. New instances of postoperative endocrinopathy occurred as follows: hypogonadism (one of six cases), GH deficiency (four of seven cases), hypothyroidism (11 of 14 cases), hypocortisolemia (eight of 15 cases), and DI (nine of 16 cases). No instance of preoperative endocrinopathy was corrected through TC surgery. Four patients (22%) exhibited short-term memory loss and 11 (61%) had hyperphagia after surgery. When compared with those in the TC group, patients in the TN group had shorter hospital stays.
Conclusions. Use of the TN approach can render good outcomes in properly selected patients with craniopharyngioma, particularly when the tumor is cystic. Even in mostly suprasellar cases, an extended TN approach can afford complete resection. Note that endocrine function often worsens after surgery and that postoperative obesity can be a significant problem.
Ben A. Strickland, Ian E. McCutcheon, Indro Chakrabarti, Laurence D. Rhines and Jeffrey S. Weinberg
Metastasis to the spinal cord is rare, and optimal management of this disease is unclear. The authors investigated this issue by analyzing the results of surgical treatment of spinal intramedullary metastasis (IM) at a major cancer center.
The authors retrospectively reviewed the medical records of 13 patients who underwent surgery for IM. Patients had renal cell carcinoma (n = 4), breast carcinoma (n = 3), melanoma (n = 2), non–small cell lung cancer (n = 1), sarcoma (n = 1), adenoid cystic carcinoma (n = 1), and cervical cancer (n = 1). Cerebrospinal fluid was collected before surgery in 11 patients, and was negative for malignant cells, as was MRI of the neuraxis. Eleven patients presented with neurological function equivalent to Frankel Grade D.
Radiographic gross-total resection was achieved in 9 patients, and tumor eventually recurred locally in 3 of those 9 (33%). Leptomeningeal disease was diagnosed in 4 patients after surgery. In the immediate postoperative period, neurological function in 6 patients deteriorated to Frankel Grade C. At 2 months, only 2 patients remained at Grade C, 8 were at Grade D, and 1 had improved to Grade E. One patient developed postoperative hematoma resulting in Frankel Grade A. Radiotherapy was delivered in 8 patients postoperatively. The median survival after spine surgery was 6.5 months. Three patients are still living.
Surgery was performed as a last option to preserve neurological function in patients with IM. In most patients, neurological function returned during the immediate postoperative period and was preserved for the patients’ remaining lifetime. The data suggest that surgery can be effective in preventing further decline in selected patients with progressive neurological deficit.
Kern H. Guppy, Indro Chakrabarti, Richard S. Isaacs and Jae H. Jun
En bloc resection of cervical chordomas has led to longer survival rates but has resulted in significant morbidities from the procedure, especially when the tumor is multilevel and located in the high-cervical (C1–3) region. To date, there have been only 5 reported cases of multilevel en bloc resection of chordomas in the high-cervical spine. In this technical report the authors describe a sixth case. A complete spondylectomy was performed at C-2 and C-3 with spinal reconstruction and stabilization, using several new modalities that were not used in the previous cases. The use of 1) preoperative endovascular sacrificing of the vertebral artery, 2) CT image-guidance, 3) an ultrasonic aspirator for skeletonizing the vertebral artery, and 4) the custom design of an anterior cage all contributed to absence of intraoperative or long-term (20 months) hardware failure and pseudarthrosis.
Ganesh Rao, Chul S. Ha, Indro Chakrabarti, Iman Feiz-Erfan, Ehud Mendel and Laurence D. Rhines
Metastases of multiple myeloma often occur in the cervical spine. These metastases may cause pain and associated spinal instability. The authors report the results of radiotherapy and surgical treatment for myeloma involving the cervical spine. The results of radiation therapy for multiple myeloma metastases to the cervical spine that cause clinical or radiographically documented instability have not been reported previously.
A retrospective chart review of patients with multiple myeloma metastases to the cervical spine was undertaken. Between 1993 and 2005, 35 patients were treated with external-beam radiation and/or surgical stabilization at the University of Texas M. D. Anderson Cancer Center in Houston, Texas. Nineteen of 20 patients with sufficient follow-up data experienced resolution of their pain when treated with radiation without surgical intervention. Twenty-three patients had evidence of spinal instability on radiographic images; 15 of these were treated with radiation alone. Of these, 10 had sufficient follow-up data, and none showed any clinical progression of instability. Radiographic follow-up images demonstrated an arrest of further progression of instability and, in some cases, healing of pathological fractures by means of radiation alone.
The results of this series suggest that, in selected cases, external-beam radiation for multiple myeloma metastases to the cervical spine is an effective palliative treatment, even in cases involving clinical or radiographically documented instability.
Iman Feiz-Erfan, Benjamin D. Fox, Remi Nader, Dima Suki, Indro Chakrabarti, Ehud Mendel, Ziya L. Gokaslan, Ganesh Rao and Laurence D. Rhines
Hematogenous metastases to the sacrum can produce significant pain and lead to spinal instability. The object of this study was to evaluate the palliative benefit of surgery in patients with these metastases.
The authors retrospectively reviewed all cases involving patients undergoing surgery for metastatic disease to the sacrum at a single tertiary cancer center between 1993 and 2005.
Twenty-five patients (21 men, 4 women) were identified as having undergone sacral surgery for hematogenous metastatic disease during the study period. Their median age was 57 years (range 25–71 years). The indications for surgery included palliation of pain (in 24 cases), need for diagnosis (in 1 case), and spinal instability (in 3 cases). The most common primary disease was renal cell carcinoma.
Complications occurred in 10 patients (40%). The median overall survival was 11 months (95% CI 5.4–16.6 months). The median time from the initial diagnosis to the diagnosis of metastatic disease in the sacrum was 14 months (95% CI 0.0–29.3 months). The numerical pain scores (scale 0–10) were improved from a median of 8 preoperatively to a median of 3 postoperatively at 90 days, 6 months, and 1 year (p < 0.01). Postoperative modified Frankel grades improved in 8 cases, worsened in 3 (due to disease progression), and remained unchanged in 14 (p = 0.19). Among patients with renal cell carcinoma, the median overall survival was better in those in whom the sacrum was the sole site of metastatic disease than in those with multiple sites of metastatic disease (16 vs 9 months, respectively; p = 0.053).
Surgery is effective to palliate pain with acceptable morbidity in patients with metastatic disease to the sacrum. In the subgroup of patients with renal cell carcinoma, those with the sacrum as their solitary site of metastatic disease demonstrated improved survival.
Flexion-extension magnetic resonance imaging
John W. Gilbert, Greg R. Wheeler, Gregory E. Mick and Stephanie L. Herder
Indro Chakrabarti, Allen W. Burton, Ganesh Rao, Iman Feiz-Erfan, Roman Hlatky, Laurence D. Rhines and Ehud Mendel
✓ The authors report the use of percutaneous transpedicular vertebroplasty performed using polymethylmethacrylate (PMMA) in two patients. These men (53 and 57 years old) had previously undergone open surgery and posterior instrumentation to treat myelomatous compression fractures. Both patients presented with acute back pain that manifested after minor activities. Kyphotic wedge fractures were diagnosed at T-11 in one case and at L-1 in the other. Both patients were treated at other hospitals with laminectomy and instrumented fusion; multiple myeloma was diagnosed after surgery. The patients experienced severe, recalcitrant, and progressive pain; on referral, they were found to have persistent kyphosis. Multiple myelomatous lesions of the spine were seen in one case and in the other the L-1 fracture represented the only site of disease. Percutaneous vertebroplasty was performed by injecting PMMA into the anterior third of the compressed vertebral body. Both patients experienced a 50% reduction in pain immediately after treatment; 3 months later both were walking and reported minimal back pain while undergoing treatment for multiple myeloma. Three years after surgery one patient reported no back pain and no progressive instability of the spine. Four years after surgery the other patient remains pain free, ambulatory, and with overall disease remission.
Percutaneous vertebroplasty provided effective analgesia in these two patients with progressive back pain despite posterior stabilization. In both cases, the anterior column was effectively stabilized. A much larger operative intervention with its attendant risks of morbidity was avoided. In addition, subsequent aggressive medical treatment was well tolerated.
Ganesh Rao, Dima Suki, Indro Chakrabarti, Iman Feiz-Erfan, Milan G. Mody, Ian E. McCutcheon, Ziya Gokaslan, Shreyaskumar Patel and Laurence D. Rhines
Sarcomas of the spine are a challenging problem due to their frequent and extensive involvement of multiple spinal segments and high recurrence rates. Gross-total resection to negative margins, with preservation of neurological function and palliation of pain, is the surgical goal and may be achieved using either intralesional resection or en bloc excision. The authors report outcomes of surgery for primary and metastatic sarcomas of the mobile spine in a large patient series.
A retrospective review of patients undergoing resection for sarcomas of the mobile spine between 1993 and 2005 was undertaken. Sarcomas were classified by histology study results and as either primary or metastatic. Details of the surgical approach, levels of involvement, and operative complications were recorded. Outcome measures included neurological function, palliation of pain, local recurrence, and overall survival.
Eighty patients underwent 110 resections of either primary or metastatic sarcomas of the mobile spine. Twenty-nine lesions were primary sarcomas (36%) and 51 were metastatic sarcomas (64%). Intralesional resections were performed in 98 surgeries (89%) and en bloc resections were performed in 12 (11%). Median survival from surgery for all patients was 20.6 months. Median survival for patients with a primary sarcoma of the spine was 40.2 months and was 17.3 months for patients with a metastatic sarcoma. Predictors of improved survival included a chondrosarcoma histological type and a better preoperative functional status, whereas osteosarcoma and a high-grade tumor were negative influences on survival. Multivariate analysis showed that only a high-grade tumor was an independent predictor of shorter overall survival. American Spinal Injury Association scale grades were maintained or improved in 97% of patients postoperatively, and there was a significant decrease in pain scores postoperatively. No significant differences in survival or local recurrence rates between intralesional or en bloc resections for either primary or metastatic spine sarcomas were found.
Surgery for primary or metastatic sarcoma of the spine is associated with an improvement in neurological function and palliation of pain. The results of this study show a significant difference in patient survival for primary versus metastatic spine sarcomas. The results do not show a statistically significant benefit in survival or local recurrence rates for en bloc versus intralesional resections for either metastatic or primary sarcomas of the spine, but this may be due to the small number of patients undergoing en bloc resections.