(P 484) OBESITY INCREASES THE RISK OF MAJOR WOUND COMPLICATIONS FOLLOWING PELVIC RESECTION FOR BONE SARCOMA

Objective: Obesity in malignant bone tumours is a non-modifiable risk factor given the time sensitive nature of the disease. Elevated body mass index (BMI) increases the risk of surgical site infections and wound complications in limb bone sarcoma treatment. However, there is a paucity of data in the literature on the effect of obesity in patients who undergo pelvic resections. The objective of this study is to evaluate the association between obesity and major wound complications in pelvic bone sarcoma surgery.

Methods: Consecutive patients who underwent pelvic resection to treat bone sarcoma from 2005 to 2021 were reviewed from a prospectively collected single-centre database. The minimum follow-up was six months. Patients with benign tumours or primary soft tissue sarcomas were excluded. Patients were evaluated for major and minor wound complications. Major wound complication was defined as the need for a secondary surgical debridement procedure. Patients with minor wound complications only required bedside wound care with or without antibiotics. Primary outcomes were the effects of obesity on the rate of wound complications. Patients were classified according to their body mass index (BMI): obese (≥ 30kg/m2), overweight (25-29.9 kg/m2), healthy weight (18.5-24.9 kg/m2), underweight ( < 18.5kg/m2). Secondary analysis was performed to identify any independent risk factors for wound complications.

Results: Among the 106 included patients, the number of obese, overweight, healthy weight, and underweight patients was 23, 35, 45, and three respectively. Twenty-seven patients sustained a major wound complication and eight patients were treated for a minor wound issue. The proportion of obese patients who sustained a major wound complication was significantly higher compared to overweight, healthy weight, and underweight patients (12/23 (52%), 6/35 (17%), 9/45 (20%), and 0/3 respectively, p = 0.0087). The odds ratio and relative risk of a major wound complication among obese patients were 4.95 and 2.89 respectively. Other factors including patient age, sex, tumour histology, tumour volume, tumour grade, type of reconstruction, type of closure (primary vs. soft tissue reconstruction), neo-adjuvant radiation therapy and/or chemotherapy did not significantly affect outcomes. The BMI status did not play a significant role in the rate of minor wound complications.

Conclusion: Obesity is associated with an increased rate of major wound complications requiring a secondary surgical debridement procedure in patients who undergo pelvic resection for bone sarcoma. This highlights the importance of careful intraoperative and perioperative wound management as well as patient education to optimize outcomes.