Effects of Obesity on Minimally Invasive Lumbar Spine Surgery: A Systematic Review and Meta-Analysis

Background Obesity is linked to increased spinal degenerative pathology and higher perioperative risks in spinal surgery. As the global obesity rates continue to rise, spine surgeons increasingly turn to minimally invasive approaches to theoretically minimize risk, but its outcomes are unclear. Objective To evaluate the impact of obesity on perioperative outcomes in minimally invasive surgery (MIS) for the lumbar spine. Methods A systematic review and meta-analysis were conducted using the MEDLINE, Embase, and Cochrane databases to examine the effects of obesity on MIS lumbar spine surgeries. Perioperative outcomes were categorized by surgical procedures, specifically lumbar fusion and decompression surgeries. Patients with obesity were further stratified into 2 groups: (1) obese (all classes) vs nonobese, and (2) class II/III obese vs nonobese. Results Twenty-six cohort studies met the inclusion criteria. In MIS lumbar fusion procedures, patients with obesity experienced higher blood loss (14 studies, n = 3128; mean difference [MD] 21.54; 95% CI 4.29–38.78), longer surgical times (16 studies, n = 3353; MD 19.41, 95% CI 8.12–30.70), and increased length of hospital stay (13 studies, n = 3222; MD 0.36, 95% CI 0.14–0.58). Similarly, for MIS lumbar decompression surgeries, patients with obesity had higher blood loss (6 studies, n = 1318; MD 17.02, 95% CI 1.23–32.80), longer operative times (8 studies, n = 1294; MD 17.80, 95% CI 4.36–31.25), and extended hospital stays (10 studies, n = 1892; MD 0.41, 95% CI 0.06–0.76). There was an increased rate of revision surgery in patients with obesity undergoing decompression procedures (7 studies, n = 1397; relative risk 1.43, 95% CI 1.04–1.96). Obesity was not associated with increased risks of short-to-mid-term surgical complications, infections, pseudarthrosis, or higher opioid use. Conclusion While MIS for obese lumbar spine patients may mitigate perioperative risk, it does not eliminate it. Obesity remains associated with increased blood loss, longer operative times, extended hospital stays, and higher revision rates. Future research should investigate mid- to long-term consequences, including complications, pseudarthrosis, and rates of revision surgery, in patients with obesity undergoing MIS lumbar interventions. Clinical Relevance Patients should be counseled about the risks associated with obesity, and preoperative weight optimization is recommended to improve outcomes.