Predictability of first-year weight loss in laparoscopic sleeve gastrectomy

Bariatric surgery is a significant investment for the patient and weight loss team. In some cases, this includes a requirement for pre-operative weight loss despite the lack of evidence for a correlation with successful outcomes. We sought to determine whether weight loss on a short, immediate pre-operative diet, as well as across the medical weight loss program, would correlate with 1-year outcomes of patients undergoing laparoscopic sleeve gastrectomy (LSG).

All patients having a LSG between March 2013 and March 2016 were reviewed. Demographics and biometrics [weight, body mass index (BMI)] were collected at initial, day of surgery and follow-up (2 weeks, 6 weeks, 4 months, and 1 year). Pre-operative weight loss was determined both cumulative (initial to day of surgery) and for the pre-operative diet (2 weeks). Weight loss and percent excess weight loss (%EWL) were calculated and correlated at all time points.

A total of 127 patients were reviewed for this study. The mean %EWL at 1-year follow-up was 47 ± 18%. Weight loss achieved on a 2-week pre-operative diet did not correlate with weight outcomes at 1-year follow-up (r = 0.134, p = 0.40); however, cumulative pre-operative weight loss had a modest correlation (r = 0.443, p < 0.01). Post-operative %EWL at 4 months had the best correlation with longer term weight loss (r = 0.730, p < 0.01).

Pre-operative performance is not a good predictor for 1-year outcomes in LSG. Better correlation was observed in %EWL at post-surgery visits. Following the patient's trajectory post-operatively may provide a window for intervention to improve weight loss.