Influence of body mass index on outcomes in patients undergoing surgery for diverticular disease

We hypothesized that increasing body mass index is a risk factor for surgical complications in surgery for diverticulitis. We assessed the relationship of body mass index and surgical complications following surgery for diverticular disease.

We used National Surgical Quality Improvement Program database from 2005 to 2015. Patients undergoing surgery for diverticular disease during that period were included and stratified into 9 groups based on their body mass index (< 18.5, 18.6-24.9, 25.0-29.9, 30.0-34.9, 35.0-39.9, 40.0-44.9, 45.0-49.9, 50.0-54.9, > 55). Outcomes of interest were complications of superficial surgical site infection, deep incisional surgical site infection, organ space surgical site infection, wound disruption complications, pneumonia, ventilator dependence > 48 hours, acute renal failure, myocardial infarction, return to operating room, and 30-day mortality.

Morbidly obese patients had higher rates of diabetes, hypertension, and steroid use. They had higher American Society of Anesthesiologists classification and were more likely to have emergency and open cases. Interestingly, increased body mass index was inversely associated with age. Increasing body mass index was associated with worse outcomes including superficial surgical site infection, deep incisional surgical site infection, organ space surgical site infection, wound disruption complications, ventilator dependence > 48 hours, acute renal failure, and return to operating room. Risk of developing pneumonia didn't have similar correlation with body mass index. Overweight status had protective effect on mortality. No statistically significant differences in increased rates of myocardial infarction were noted. Underweight patients also developed worse outcomes.

Obesity is associated with a number of complications following surgery for diverticulitis. Elevated body mass index adds significant risk to procedures for diverticulitis and should be accounted for in risk stratification models. Patients should be counseled on weight reduction before undergoing elective surgery for diverticular disease.