Survival Outcomes and Factors Associated with Revision Surgery for Metastatic Disease of the Spine

Abstract

Study Design Retrospective review of a prospective database. Objective Certain subset of patients undergoing surgical treatment for spinal metastasis will require a revision surgery in their disease course; however, factors predictive of revision surgery and survival outcomes are largely unknown. The goal of this study is to report on survival outcomes as well as factors predictive of revision surgery in this unique patient population. Methods A total of 55 patients who met the inclusion criteria were included from January 2010 to December 2015. Twelve (22%) of these patients underwent a revision surgery. Patient and tumor characteristics were summarized and survival outcomes were evaluated using Kaplan-Meier methods and Cox proportional hazards regression. Results Both the revision and the nonrevision groups were similarly matched with respect to spine disease burden, neurological status at time of initial presentation, primary malignancy types, and the use of adjuvant treatment modalities. Tumor progression (66.7%) was the most common reason for necessitating a revision followed by nonunion (16.7%), wound dehiscence (8.3%), and construct failure (8.3%). Following multivariate model selection procedures, smokers were found to have 3.5 times increased odds of undergoing revision compared to nonsmokers (p = 0.05). Analysis of survival curves showed that the median survival in the revision group was 3.0 years (95% CI: 1.5, 4.1), while the median survival in the nonrevision group was 1.5 years (95% CI: 1.1, 2.3; log-rank test, p = 0.105). Conclusion Despite aggressive treatment, tumor progression is the most common reason for revision surgery. Smoking is an independent risk factor for revision. Revision surgery should be considered in patients when indicated as it does not appear to detrimentally affect survival.

Commentary: Does Low-Grade Versus High-Grade Bilsky Scores Influence Local Recurrence and Overall Survival in Metastatic Spine Tumor Surgery?

“…of stay, and morbidity to the operation, and it decreases spinal column stability. 6,7 Surprisingly, the overall incidence of corpectomy and instrumentation is extremely high in this study (55.4% and 97.1%, respectively), and it is not matching with the literature. Although the authors did not provide clear explanation about this discrepancy in the discussion, the presence of spinal instability either due to multiple-level pathological vertebral fractures or multiplelevel surgical decompression might provide some justification.…”

“…For example, performing transpedicular decompression adds more complexity, operative time, blood loss, length of stay, and morbidity to the operation, and it decreases spinal column stability. 6,7…”

Hardware Failure in Spinal Tumor Surgery: A Hallmark of Longer Survival?

“…The stability of a spinal construct is dependent on achieving a timely bony fusion [ 12 ]. Local and systemic effects of spine tumors do not favor this outcome [ 2 , 14 ]. In addition, oncological patients often have a poor mobility and nutrition, and frequently undergo radiation and chemotherapy, which would further compromise the fusion bed [ 12 ].…”

“…Mortality after surgery for spinal tumors depends on a variety of factors, including patient age, comorbidities, and tumor type [ 33 ]. Prior research has shown a longer median survival rate for patients who undergo a revision surgery versus those who do not [ 14 ]. Patients in our study with hardware failures had longer overall survival.…”

Treatment Outcomes in Spinal Metastatic Disease With Indeterminate Stability

“…The surgical revision rate in this study was consistent with previous reports in the literature ranging from 10.7% to 22%. 30,31 In the KþE group, only 2 patients were revised with surgical decompression and stabilization due to progressive neurologic deficits related to tumor progression. No patients in the SþE or KþE underwent repeat treatment for persistent pain alone.…”