Complications and reoperations after surgery for 647 patients with spine metastatic disease.

BACKGROUND CONTEXT: Postoperative morbidity may offset the potential benefits of surgical treatment for spine metastatic disease; hence, risk factors for postoperative complications and reoperations should be taken into considerations during surgical decision-making. In addition, it remains unknown whether complications and reoperations shorten these patients' survival.

PURPOSE: We aimed to describe and identify factors associated with having a complication within 30 days of index surgery as well as factors associated with having a subsequent reoperation. Furthermore, we assessed the effect of 30-day complications and reoperations on the patients' postoperative survival, as well as described neurologic changes after surgery.

STUDY DESIGN: Retrospective cohort study.

PATIENT SAMPLE: We included 647 patients 18 years and older who had surgery for metastatic disease in the spine between January 2002 and January 2014 in one of two affiliated tertiary care centers.

OUTCOME MEASURES: Our primary outcomes were complications within 30 days after surgery and reoperations until final follow-up or death.

METHODS: We used multivariate logistic regression to identify risk factors for 30-day complications and reoperations. We used the Cox regression analysis to assess the effect of postoperative complications and reoperations on survival.

RESULTS: From 647 included patients, 205 (32%) had a complication within 30 days. The following variables were independently associated with 30-day complications: lower albumin levels (odds ratio [OR]: 0.69, 95% confidence interval [CI]=0.49-0.96, p=.021), additional comorbidities (OR=1.42, 95% CI=1.00-2.01, p=.048), pathologic fracture (OR=1.41, 95% CI=0.97-2.05, p=.031), three or more spine levels operated upon (OR=1.64, 95% CI=1.02-2.64, p=.027), and combined surgical approach (OR=2.44, 95% CI=1.06-5.60, p=.036). One hundred and fifteen patients (18%) had at least one reoperation after the initial surgery; prior radiotherapy (OR=1.56, 95% CI=1.07-2.29, p=.021) to the spinal tumor was independently associated with reoperation. 30-day complications were associated with worse survival (hazard ratio [HR]=1.40, 95% CI=1.17-1.68, p<.001), and reoperation was not significantly associated with worse survival (HR=0.80, 95% CI=0.09-1.00, p=.054). Neurologic status worsened in 42 (6.7%), remained stable in 445 (71%), and improved in 140 (22%) patients after surgery.

CONCLUSIONS: Three or more spine levels operated upon and prior radiotherapy should prompt consideration of a preoperative plastic surgery consultation regarding soft tissue coverage. Furthermore, if time allows, aggressive nutritional supplementation should be considered for patient with low preoperative serum albumin levels. Surgeons should be aware of the increase in complications in patients presenting with pathologic fracture, undergoing a combined approach, and with any additional preoperative comorbidities. Importantly, 30-day complications were associated with worsened survival.