Efficacy of a Required Preoperative Weight Loss Program for Patients Undergoing Bariatric Surgery

The efficacy of mandatory medically supervised preoperative weight loss (MPWL) prior to bariatric surgery continues to be a controversial topic. The purpose of this observational study was to assess the efficacy of a MPWL program in a single institution, which mandated at least 10% excess body weight loss before surgery, by comparing outcomes of patients undergoing primary bariatric surgery with and without a compulsory preoperative weight loss regimen. We analyzed our database of 757 patients who underwent primary bariatric surgery between March 2008 and January 2015. Patients were placed into two cohorts based on their participation in a MPWL program requiring at least 10% excess weight loss (EWL) prior to surgery. Patients were evaluated at 3, 6, 12, and 24 months after surgery for weight loss, comorbidity resolution, and the occurrences of hospital readmissions. A total of 717 patients met the inclusion criteria of whom 465 underwent surgery without a preoperative weight loss requirement and 252 participated in the MPWL program. One year after surgery, 67.1% of non-participants and 62.5% of MPWL participants showed a resolution of at least one of five associated comorbidities (p = 0.45). Non-participants showed an average of 58.6% EWL, while MPWL participants showed 59.1% EWL at 1 year postoperatively (p = 0.84). Readmission rates, excluding those which were ulcer-related, at 30 days (3.4 vs. 6.40%, p = 0.11) and 90 days (9.9 vs. 7.5%, p = 0.29) postoperatively were not significantly different between the non-participants and MPWL patients, respectively. A mandatory preoperative weight loss program prior to bariatric surgery did not result in significantly greater %EWL or comorbidity resolution 1 year after surgery compared to patients not required to lose weight preoperatively. Additionally, the program did not result in significantly lower 30- or 90-day readmission rates for these patients. The value of a MPWL program must be weighed against the potential loss of bariatric surgery candidates. Patients who fail to lose 10% excess weight preoperatively are thus ineligible for a procedure from which they would otherwise benefit. Our data suggest these patients will have similar positive outcomes.