Assessing Risk of Anterior Exposure for Anterior Lumbar Interbody Fusion in Obese Patients.

Introduction: Though obesity is common in patients undergoing anterior lumbar interbody fusion (ALIF), complications in those with BMI ≥30 kg/m are incompletely characterized. This retrospective study of ALIF patients aims to establish predictors of perioperative complications relating to anterior exposure. Our hypothesis was that obesity would be associated with increased rates of intraoperative and postoperative complications.

Methods: We retrospectively reviewed patients who underwent ALIF from 2013 to 2023 at our institution, excluding patients with age <18 y, incalculable body mass index (BMI), or revision ALIF. The primary end point was perioperative complications (intraoperative injury, wound infection, wound dehiscence, hernia, deep venous thrombosis/pulmonary embolism, ileus, new neurologic deficit, and mortality). Secondary end points included length of stay, need for reoperation, and 30-d readmission rates. Regression (univariate and multivariate) analyses were conducted to compare patients with BMI ≥30 kg/m versus BMI <30 kg/m.

Results: Of 478 patients, 230 (48.1%) had BMI <30 kg/m. BMI ≥30 kg/m was associated with an increased risk of anterior wound complication (odds ratio (OR): 3.45, 95% confidence interval (CI): 1.39, 9.84, P = 0.0012). In addition, BMI 30-35 kg/m and BMI ≥40 kg/m were associated with a 3.25 (95% CI: 1.19, 9.74, P = 0.025) and 5.67 (95% CI: 1.48-20.9, P = 0.009) increased odds of anterior wound complication, respectively. This included wound dehiscence, superficial site infection, and/or abscess, occurring in 29 patients. Of the six patients who subsequently required operative take back, five were obese. Intraoperative injury occurred in 30 patients (6.3%) during the anterior exposure, including vessel injury (n = 24) and bladder injury (n = 1) and trended to be more frequent in obese patients (OR: 1.95, 95% CI: 0.88-4.59, P = 0.11).

Conclusions: In patients who undergo ALIF, there is a significant association between anterior wound complications and obesity. However, the overall rate of intraoperative complications was low. We demonstrated safe performance of ALIF in our patient group with higher BMI.