Minimal Invasive Surgery Instrumented Fusion versus Conventional Open Surgical Instrumented Fusion for the Treatment of Spinal Metastases: A Systematic Review and Meta-analysis

OBJECTIVE: In this study, we aimed to compare the minimally invasive surgery (MIS) instrumented fusion +/- decompression versus conventional open surgery (COS) instrumented fusion +/- decompression for the treatment of spinal metastases. METHODS: We performed a systematic literature search through PubMed, Scopus, Europe PMC (PubMed Central), and Cochrane Central Database using the keywords "minimal invasive surgery" OR "minimally invasive surgery" OR "mini-open" AND "conventional open surgery" OR "traditional open surgery" OR "open surgery" AND "spinal metastasis". The outcomes of interest were complications, neurologic improvement, length of stay, intraoperative blood loss, transfusion rate, and operative duration. RESULTS: There were a total of 8 studies comprising 486 patients. Complications were less frequent in MIS compared with COS (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.30-0.84; P = 0.01; I-2 = 0%). Major complications related to surgery were less in the MIS group (OR, 0.42; 95% CI, 0.21-0.84; P = 0.01; I-2 = 0%). The rate of neurologic improvement was similar in both groups (OR, 1.01; 95% CI, 0.64-1.59; P = 0.95; I-2 = 0%). MIS was associated with less blood loss (mean difference, -690.00 mL; 95% CI, -888.31 to -491.69; P < 0.001; I-2 [ 56%), and lower transfusion rate compared with COS (OR, 0.27; 95% CI, 0.11-0.66; P [0.004; I-2 = 50%). Length of surgery was similar in both groups (mean difference, -12.49 minutes; 95% CI, -45.93 to 20.95; P = 0.46; I-2 = 86%). MIS resulted in shorter length of stay compared with COS (mean difference -3.58 days; 95% CI, -6.90 to -0.26; P = 0.03; I-2 = 89%). CONCLUSIONS: MIS was associated with lower complications, blood loss, transfusion rate, and shorter length of stay with a similar rate of neurologic improvement and length of surgery compared with COS.