Conversion of standard Roux-en-Y gastric bypass to distal bypass for weight loss failure and metabolic syndrome: 3-year follow-up and evolution of technique to reduce nutritional complications.

BACKGROUND: Standard proximal Roux-en-Y gastric bypass (RYGB) fails to achieve long-term weight maintenance and/or control of metabolic syndrome in up to 35% of patients.

OBJECTIVES: To improve the performance of the standard proximal gastric bypass by increasing the biliopancreatic limb length at the expense of the common channel.

SETTINGS: Academic-affiliated private practice.

METHODS: A retrospective review of all patients who underwent conversion to distal RYGB from 2010 to 2016 was performed. RYGB was modified by dividing the Roux limb at the jejunojejunostomy and transposing it distally to create a shortened total alimentary limb length (TALL) of 250 to 300 cm in the initial 11 patients. Of these, 7 developed protein calorie malnutrition and diarrhea requiring a second procedure to lengthen the common channel an additional 100 to 150 cm (TALL 400-450 cm), leading to resolution of all symptoms. The subsequent 85 patients were converted to distal RYGB with TALL 400 to 450 in a single-stage operation.

RESULTS: Ninety-six RYGB patients underwent conversion to distal RYGB. The mean body mass index and mean excess weight loss at the time of distalization was 40.6 kg/m2 and 33.6%. At 1, 2, and 3 years after distalization, the mean body mass index was reduced to 34.4, 33.1, and 32.2 kg/m2 , respectively, and excess weight loss improved to 41.9%, 53.7%, and 65.7%, respectively. Diabetes resolved in 66.7%, hypertension resolved in 28.6%, hyperlipidemia resolved in 40%, and sleep apnea resolved in 50% at 1 year. The 30-day complication rate and reoperation rates were 6.3% and 5.2%; an additional 7.3% (7/96) required reoperation for limb lengthening. Hypoalbuminemia developed in 21% at 3 years, but no increase in iron deficiency was observed. Calcium metabolism was affected by the distalization procedure to a greater degree as 21% of patients had low corrected calcium levels, 77% were deficient in vitamin D, and parathyroid hormone levels were above normal in 64% at 3 years.

CONCLUSION: Revision of proximal RYGB to distal RYGB results in substantial improvement in weight loss and resolution of co-morbidities at 3 years. Diarrhea and protein calorie malnutrition were seen frequently in patients with TALL of 250 to 300 cm, whereas patients with TALL 400 to 450 cm demonstrated a lower incidence of nutritional issues, but the effect on calcium, parathyroid hormone, and the fat soluble vitamins A and D is still a major concern.