Scott L. Zuckerman, Ganesh Rao, Laurence D. Rhines, Ian E. McCutcheon, Richard G. Everson and Claudio E. Tatsui
Treatment of epidural spinal cord compression (ESCC) caused by tumor includes surgical decompression and stabilization followed by postoperative radiation. In the case of severe axial loading impairment, anterior column reconstruction is indicated. The authors describe the use of interbody distraction to restore vertebral body height and correct kyphotic angulation prior to reconstruction with polymethylmethacrylate (PMMA), and report the long-term durability of such reconstruction.
A single institution, prospective series of patients with ESCC undergoing single-stage decompression, anterior column reconstruction, and posterior instrumentation from 2013 to 2016 was retrospectively analyzed. Several demographic, perioperative, and radiographic measurements were collected. Descriptive statistics were compiled, in addition to postoperative changes in anterior height, posterior height, and kyphosis. Paired Student t-tests were performed for each variable. Overall survival was calculated using the techniques described by Kaplan and Meier.
Twenty-one patients underwent single-stage posterior decompression with interbody distraction and anterior column reconstruction using PMMA. The median age and Karnofsky Performance Scale score were 61 years and 70, respectively. Primary tumors included renal cell (n = 8), lung (n = 4), multiple myeloma (n = 2), prostate (n = 2), and other (n = 5). Eighteen patients underwent a single-level vertebral body reconstruction and 3 underwent multilevel transpedicular corpectomies. The median survival duration was 13.3 months. In the immediate postoperative setting, statistically significant improvement was noted in anterior body height (p = 0.0017, 95% confidence interval [CI] −4.15 to −1.11) and posterior body height (p = 0.0116, 95% CI −3.14 to −0.45) in all patients, and improved kyphosis was observed in those with oblique endplates (p = 0.0002, 95% CI 11.16–20.27). In the median follow-up duration of 13.9 months, the authors observed 3 cases of asymptomatic PMMA subsidence. One patient required reoperation in the form of extension of fusion.
In situ interbody distraction allows safe and durable reconstruction with PMMA, restores vertebral height, and corrects kyphotic deformities associated with severe pathological fractures caused by tumor. This is accomplished with minimal manipulation of the thecal sac and avoiding an extensive 360° surgical approach in patients who cannot tolerate extensive surgery.
Jonathan N. Sellin, Dima Suki, Viraat Harsh, Benjamin D. Elder, Daniel K. Fahim, Ian E. McCutcheon, Ganesh Rao, Laurence D. Rhines and Claudio E. Tatsui
Spinal metastases account for the majority of bone metastases from thyroid cancer. The objective of the current study was to analyze a series of consecutive patients undergoing spinal surgery for thyroid cancer metastases in order to identify factors that influence overall survival.
The authors retrospectively reviewed the records of all patients who underwent surgery for spinal metastases from thyroid cancer between 1993 and 2010 at the University of Texas MD Anderson Cancer Center.
Forty-three patients met the study criteria. Median overall survival was 15.4 months (95% CI 2.8–27.9 months) based on the Kaplan-Meier method. The median follow-up duration for the 4 patients who were alive at the end of the study was 39.4 months (range 1.7–62.6 months). On the multivariate Cox analysis, progressive systemic disease at spine surgery and postoperative complications were associated with worse overall survival (HR 8.98 [95% CI 3.46–23.30], p < 0.001; and HR 2.86 [95% CI 1.30–6.31], p = 0.009, respectively). Additionally, preoperative neurological deficit was significantly associated with worse overall survival on the multivariate analysis (HR 3.01 [95% CI 1.34–6.79], p = 0.008). Conversely, preoperative embolization was significantly associated with improved overall survival on the multivariate analysis (HR 0.43 [95% CI 0.20–0.94], p = 0.04). Preoperative embolization and longer posterior construct length were significantly associated with fewer and greater complications, respectively, on the univariate analysis (OR 0.24 [95% CI 0.06–0.93] p = 0.04; and OR 1.24 [95% CI 1.02–1.52], p = 0.03), but not the multivariate analysis.
Progressive systemic disease, postoperative complications, and preoperative neurological deficits were significantly associated with worse overall survival, while preoperative spinal embolization was associated with improved overall survival. These factors should be taken into consideration when considering such patients for surgery. Preoperative embolization and posterior construct length significantly influenced the incidence of postoperative complications only on the univariate analysis.
Claudio E. Tatsui, Dima Suki, Ganesh Rao, Stefan S. Kim, Abhijit Salaskar, Mustafa Aziz Hatiboglu, Ziya L. Gokaslan, Ian E. McCutcheon and Laurence D. Rhines
Renal cell carcinoma (RCC) frequently metastasizes to the spine, and the prognosis can be quite variable. Surgical removal of the tumor with spinal reconstruction has been a mainstay of palliative treatment. The ability to predict prognosis is valuable when determining the role and magnitude of surgical intervention in cancer patients. To better identify factors affecting survival in patients undergoing surgery for spinal metastasis from RCC, the authors undertook a retrospective analysis of a large patient cohort at a tertiary care cancer center.
Relevant clinical data on a consecutive series of patients who had undergone surgery for spinal metastasis of RCC between 1993 and 2007 at The University of Texas MD Anderson Cancer Center were retrospectively reviewed. Demographic data, histopathological grade of primary tumor, timing of spinal surgery relative to diagnosis, treatment history prior to surgery, neurological status, and systemic disease burden were analyzed to determine the impact of these factors on survival outcome.
The authors identified 267 patients who met the study criteria. Five-year overall survival (OS) after spine tumor resection was 7.8%, with a median OS of 11.3 months (95% CI 9.5–13.0 months). Patients with Fuhrman Grade 4 RCC had a median OS of 6.1 months (95% CI 3.5–8.7 months), which was significantly lower than the 14.3 months (95% CI 9.1–19.4 months) observed in patients with Fuhrman Grade 3 or less RCC (p < 0.001). Patients with preoperative neurological deficits had a median survival of 5.9 months (95% CI 4.1–7.7 months), which was significantly lower than the 13.5 months (95% CI 10.4–16.6 months) observed in patients with a normal neurological examination (p < 0.001). Patients whose spine was the only site of metastasis had a median OS of 19 months (95% CI 9.8–28.2 months) after surgery, significantly longer than the 9.7 months (95% CI 8.1–11.3 months) observed in patients with additional extraspinal metastasis sites (p < 0.001). Patients with nonprogressing extraspinal metastasis (no metastasis, stable, or concurrent) had a median survival of 20.6 months (95% CI 15.1–26.1 months), compared with 5.6 months (95% CI 4.4–6.8 months) in patients with progressing metastasis (p < 0.001).
The authors identified several factors influencing survival after spine surgery for metastatic spinal RCC, including grade of the original nephrectomy specimen, activity of the systemic disease, and neurological status at the time of surgery. These clinical features may help to identify patients who may benefit from aggressive surgical intervention.