Impact of BMI on postoperative outcomes in patients undergoing proctectomy for rectal cancer: A national surgical quality improvement program analysis

BACKGROUND: There is a mounting body of evidence that suggests worsened postoperative outcomes at the extremes of BMI, yet few studies investigate this relationship in patients undergoing proctectomy for rectal cancer. OBJECTIVE: We aimed to examine the relationship between BMI and short-term outcomes after proctectomy for cancer. DESIGN: This was a retrospective study comparing the outcomes of patients undergoing proctectomy for rectal cancer as they relate to BMI. SETTINGS: The American College of Surgeons-National Surgical Quality Improvement Program database was queried for this study. PATIENTS: Patients included were those who underwent proctectomy for rectal neoplasm between 2005 and 2011. MAIN OUTCOME MEASURES: Study end points included 30-day mortality and overall morbidity, including the receipt of blood transfusion, venous thromboembolic disease, wound dehiscence, renal failure, reintubation, cardiac complications, readmission, reoperation, and infectious complications (surgical site infection, intraabdominal abscess, pneumonia, and urinary tract infection). Univariate logistic regression was used to analyze differences among patients of varying BMI ranges (kg/m2; =20, 20-24, 25-29, 30-34, and =35). When significant differences were found, multivariable logistic regression, adjusting for preoperative demographic and clinical variables, was performed. RESULTS: A total of 11,995 patients were analyzed in this study. The incidences of overall morbidity, wound infection, urinary tract infection, venous thromboembolic event, and sepsis were highest in those patients with a BMI of =35 kg/m2 (OR, 1.63, 3.42, 1.47, 1.64, and 1.50). Wound dehiscence was also significantly more common in heavier patients. Patients with a BMI <20 kg/m2 had significantly increased rates of mortality (OR, 1.72) and sepsis (OR, 1.30). LIMITATIONS: This study was limited by its retrospective design. Furthermore, it only includes patients from the American College of Surgeons-National Surgical Quality Improvement Program database, limiting its generalizability to nonparticipating hospitals. CONCLUSIONS: Obese and underweight patients undergoing proctectomy for neoplasm are at a higher risk for postoperative complications and death.