Elevated Body Mass Index in Patients Undergoing Stand-alone Anterior and Lateral Lumbar Interbody Fusion: Complications, Hospital Length of Stay, and Cost.

Abstract

Retrospective cohort study. This study aims to evaluate the impact of body mass index (BMI) on postoperative outcomes following anterior, extreme lateral, and oblique lumbar interbody fusion (A/X/OLIF). Obesity is an increasingly common comorbidity among spine surgery patients, potentially leading to elevated postoperative complications. Little is known about the safety of A/X/OLIF approaches in overweight and obese patients. The PearlDiver database was queried to identify all adults who underwent single-level A/X/OLIF. Patients were stratified by BMI, defined as healthy weight (≤24.9 kg/m 2 ), overweight (25-29.9 kg/m 2 ), obese (30-39.9 kg/m 2 ), and morbidly obese (≥40 kg/m 2 ). Patient demographics and comorbidities were compared before matching, and complications were compared after matching for age, sex, and Charlson Comorbidity Index (CCI). Among the 36,716 A/X/OLIF included patients, 5464 (14.88%) were healthy weight, 9124 (24.85%) were overweight, 16,283 (44.35%) were obese, and 5845 (15.92%) were morbidly obese. The mean age was 54.4 years, 62.6% were females, and the mean CCI was 1.8. After matching, the mean age was 54.0 years, 70.1% were females, and the mean CCI was 1.4. At 90 days postoperatively, medical and surgical complication rates and readmission generally increased with increasing BMI (all P < 0.010). Length of stay (5.37, 5.51, 5.89, 6.69, P < 0.001) and 90-day costs ($19,326, $19,058, $19,680, $21,103, P = 0.002) also generally increased with increasing BMI. Intraoperative and 2-year complication rates were comparable across cohorts. Elevated BMI was associated with increased 90-day postoperative complications but not increased intraoperative or 2-year complications following A/X/OLIF. Optimization for patients with higher BMI should be performed to improve perioperative outcomes, especially in the 90-day postoperative period, and ultimately the safety of these procedures for obese patients. Level III.