Loop Duodenal Switch Surgery in Morbidly Obese Patients

Overview

The loop duodenal switch (L-DS) is a single-anastomosis biliopancreatic diversion with duodenal switch (BPD-DS) procedure. The original BPD-DS has two-anastomosis and is an accepted and approved bariatric procedure by the American Society of Metabolic and Bariatric Surgery. Preliminary data from Sanchez-Pernaute et al. (2013) indicates that the L-DS procedure is safer and easier to perform as it only requires one anastomosis compared to the BPD-DS, and offers good results for treatment of both morbid obesity and its metabolic comorbidities, including type-2 diabetes mellitus. However, the initial publications of the loop DS still resulted in a small number of patients with total protein malnutrition. For this reason, the investigators will study the loop DS with a modification of the originally published technique with a longer common channel limb (300 cm) to reduce the risk of protein malnutrition For patients with a BMI \>50, many are limited to just a sleeve gastrectomy as other bariatric procedures are technically challenging with increased operative risk. A loop duodenal switch may be a safer operation with improved weight loss for the super-morbidly obese patient.

Screening and Informed Consent Subjects will be screened on a weekly basis for eligibility of enrollment. If eligible, patients will be approached by study staff at the initial surgical consultation. The purpose of the study and risks of the procedures will be explained to the subject and the consent process must be documented accordingly in the medical record. Subjects who agree to study participation must sign an IRB-approved informed consent form. Subjects will be informed that their participation in this study is voluntary and they may refuse to participate or discontinue from the study at any time. Subjects will be given the opportunity to ask the investigator questions so that they are adequately informed about the research. A copy of the signed informed consent must be provided to the subject and the informed consent process will be documented in source documents. If new information becomes available that may affect a subject's decision to continue to take part in the study, this information will be discussed with the subject by the investigator. Failure to meet submission requirements: Each patient will be required to meet their individual insurance companies requirements for submission of bariatric surgery approval. Subjects who provide study consent but then do not submit for insurance approval or are denied will be considered "discontinued" and will not require additional study follow-up visits. The reason for the discontinuation will be clearly delineated on the applicable case report form. Subjects in who the loop duodenal switch procedure is begun but not completed will be considered "discontinued" once discharged from the hospital and not require any additional study follow-up visits. Reasons for discontinuation will be recorded in the case report form. Additionally, female patients of child bearing age will undergo a standard of care pregnancy test at the time of the pre-operative surgical testing (2/3 weeks before surgery) and always the morning of surgery by urine HCG. Surgical Procedures: The operation will be performed per standard of care and as previously described (1-3), with the exception that in this protocol the duodeno-intestinal anastomosis will be performed at approximately 300 cc with moderate stretch from the ileocecal valve, rather than 200 cm or 250 cm, as in previous reports (Cottam et al, 2015). The purpose of this change is to allow greater nutrient absorption since a previous report observed no difference in mean excess weight loss between 200 cm and 250 cm (3). In addition, the sleeve gastrectomy will be performed over a 40 French bougie. The duodeno-intestinal anastomosis will be hand-sewn. Subjects will be maintained on a low-calorie diet for the first post-operative month, as per standard of care. In addition, multivitamin supplements, calcium, and iron should be prescribed and maintained per standard of care.