Assistant Professor of Neurosurgery and Orthopaedics Vanderbilt University Medical Center Nashville, Tennessee, United States
Introduction: Factors affecting readmission after surgery for spinal metastases remain relatively unexplored. In a cohort of patients undergoing metastatic spine surgery, we sought to: 1) identify risk factors of unplanned readmission, and 2) determine the impact of an unplanned readmission on long-term outcomes.
Methods: A single-center, retrospective, case-control study was undertaken of patients undergoing spine surgery for extradural metastatic disease between 02/2010-01/2021. The primary outcome was unplanned readmission within 3-months. Preoperative, perioperative, and tumor specific variables were collected. Bivariate comparison, Kaplan-Meier plots, and multivariate cox regression were performed, controlling for tumor size, other organ metastasis, and preoperative/postoperative radiotherapy/chemotherapy.
Results: A total of 357 patients underwent surgery for spinal metastases. 3-month unplanned readmission was seen in 64/357 (21.9%) patients, 37(57.8%) were medical, 27(42.2%) were surgical, and 21(77.7%) related to their spine surgery. No significant differences were found regarding demographics and preoperative variables, except for insurance, where most readmitted patients had private insurance compared to non-readmitted patients(p=0.021). Similarly, no difference was found in preoperative radiotherapy/chemotherapy. Interestingly, readmitted patients had a higher complication rate(p < 0.001), and worse postoperative Karnofsky Performance Score (KPS)(p=0.021) and Modified McCormick Scale (MMS)(p=0.015) at the time of first postoperative follow-up. On multivariate logistic regression, postoperative complications were associated with increased readmission(OR=1.38,95%CI=1.25-1.52,p < 0.001), with no effect of postoperative KPS/MMS. Regarding long-term tumor control, Kaplan-Meier analysis showed that an unplanned readmission was associated with shorter time to local recurrence(LR)(log-rank;p=0.029) and reduced OS(log-rank;p < 0.001). Multivariate Cox Regression showed that other organ metastasis(HR=1.48,95%CI=1.13-1.93,p=0.004) and 3-months readmissions(HR=1.75,95%CI=1.28-2.39,p < 0.001) were associated with worsened OS, with no significant impact on LR. Of note, postoperative chemotherapy was significantly associated with longer OS(HR=0.59,95%CI=0.45-0.77,p < 0.001).
Conclusion : In patients undergoing surgery for spinal metastases, postoperative complications were significantly associated with unplanned readmission. Furthermore, unplanned readmission was independently associated with worsened OS. These results may help surgeons identify strategies to reduce readmissions and improve survival.
