Weight loss and malnutrition after conversion of the primary Roux-en-Y gastric bypass to distal gastric bypass in patients with morbid obesity.

Background: After Roux-en-Y gastric bypass (RYGB), 15% to 35% of patients fail to lose sufficient weight. Distalization of the limbs of the RYGB (D-RYGB) with shortening of the common channel (CC), has been used to induce additional weight loss. However, this may increase the risk of malnutrition.

Objective: The aim of this study was to assess postoperative outcomes after D-RYGB with an alimentary limb of 250 to 300 cm and CC of 100 cm.

Setting: General hospital, specialized in bariatric surgery.

Methods: We retrospectively studied all patients who underwent revision of RYGB to D-RYGB between January 2014 and April 2018. Data were collected from medical records, including weight loss, nutritional deficiencies, and co-morbidities. Questionnaires on defecation pattern, quality of life, and patient satisfaction were obtained.

Results: Forty-seven patients were included. Total weight loss (%TWL) increased significantly from 12% to 30% after D-RYGB. In 62% of patients %TWL >25% was achieved. Patients with %TWL <25% after primary RYGB, lost significantly more weight than initially reached after RYGB. Diabetes and hypertension remission occurred in 67% and 50%, respectively. Five patients (11%) needed subsequent lengthening of the CC to 250 cm due to protein malnutrition or debilitating defecation patterns. Nutritional deficiencies were present in 89% of patients after D-RYGB despite the prescription of specialized multivitamins.

Conclusion: Conversion of the primary RYGB to D-RYGB improves weight loss and co-morbidities in patients with insufficient weight loss after primary RYGB. After D-RYGB, nutritional complications and diarrhea are a risk. Based on this study, a modified D-RYGB with a longer CC of >200 cm will be considered.