Single Anastomosis Duodeno-ileal Bypass With Sleeve Gastrectomy (SADI-S): A Prospective Cohort Study

September 29, 2025 updated by: Amin Andalib, McGill University Health Centre/Research Institute of the McGill University Health Centre

The prevalence of morbid obesity in Canada has risen almost 5 fold in the past three decades. Surgery remains the cornerstone of treatment of obesity and related comorbidities such as type-2 diabetes. Bariatric/metabolic procedures can be classified into 2 main categories: a) those that cause restriction, and b) those that add a malabsorptive component to restriction. Currently sleeve gastrectomy (SG), which is a purely restrictive operation, is the most frequently performed procedure in North America.

Interestingly, combined restrictive/malabsorptive procedures such as Roux-en-Y gastric bypass (RYGB) or biliopancreatic diversion with duodenal switch (BPD-DS) are more effective procedures when compared to purely restrictive ones. Moreover, the conventional BPD-DS procedure has been shown to be significantly more effective than RYGB in achieving durable weight loss and resolving comorbidities such as type-2 diabetes. Despite superior outcomes, the performance of BPD-DS is highly institution dependant and comprises less than 5% of the annual bariatric procedures performed worldwide.

Common reservations against BPD-DS are related to the side effects of the procedure, and include frequent bowel movements, flatulence, fat, micronutrient and protein malnutrition. Furthermore, longer operative times and surgical technical challenges are also reasons for lower prevalence of the BPD-DS procedure.

Single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is a modification of the conventional BPD-DS that potentially addresses many of these concerns. In addition, it is a suitable second-stage or salvage procedure for severely obese patients with inadequate weight loss or resolution of obesity-related comorbidities after SG. Despite showing excellent results of up to 5 years with acceptable postoperative morbidity, all the literature on SADI-S originates from a single center and has not been compared directly with BPD-DS. Hence, the investigators aim to evaluate the feasibility, safety, and postoperative outcomes of SADI-S as it compares to conventional BPD-DS in morbidly obese patients.

This project has three specific aims:

  1. To evaluate feasibility and short-term safety of SADI-S.
  2. To evaluate short and long-term beneficial outcomes.
  3. To evaluate and compare long-term morbidity.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The prevalence of morbid obesity in Canada has risen almost 5 fold in the past three decades. Surgery remains the cornerstone of treatment of obesity and related comorbidities such as type-2 diabetes. Bariatric/metabolic procedures can be classified into 2 main categories: a) those that cause restriction, and b) those that add a malabsorptive component to restriction. Currently sleeve gastrectomy (SG), which is a purely restrictive operation, is the most frequently performed procedure in North America.

Interestingly, combined restrictive/malabsorptive procedures such as Roux-en-Y gastric bypass (RYGB) or biliopancreatic diversion with duodenal switch (BPD-DS) are more effective procedures when compared to purely restrictive ones. Moreover, the conventional BPD-DS procedure has been shown to be significantly more effective than RYGB in achieving durable weight loss and resolving comorbidities such as type-2 diabetes. Despite superior outcomes, the performance of BPD-DS is highly institution dependant and comprises less than 5% of the annual bariatric procedures performed worldwide.

Common reservations against BPD-DS are related to the side effects of the procedure, and include frequent bowel movements, flatulence, fat, micronutrient and protein malnutrition. Furthermore, longer operative times and surgical technical challenges are also reasons for lower prevalence of the BPD-DS procedure.

Single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is a modification of the conventional BPD-DS that potentially addresses many of these concerns. In addition, it is a suitable second-stage or salvage procedure for severely obese patients with inadequate weight loss or resolution of obesity-related comorbidities after SG. Despite showing excellent results of up to 5 years with acceptable postoperative morbidity, all the literature on SADI-S originates from a single center and has not been compared directly with BPD-DS. Hence, the investigators aim to evaluate the feasibility, safety, and postoperative outcomes of SADI-S as it compares to conventional BPD-DS in morbidly obese patients. Our project has three specific aims:

  1. To evaluate feasibility and short-term safety of SADI-S. The investigators will assess operative parameters (e.g. procedure time, inadvertent injuries, need for conversion to laparotomy, and transfusion of blood products) and 30-day postoperative adverse events (e.g. length of stay, superficial/deep surgical site infection, leak, venous thromboembolism (VTE), need for reintervention and readmission).
  2. To evaluate short and long-term beneficial outcomes. The investigators will evaluate and compare excess weight loss, resolution of type-2 diabetes and other comorbidities, and changes in quality of life at 1, 6, 12 months and yearly thereafter for both groups.
  3. To evaluate and compare long-term morbidity. The investigators will evaluate and compare both groups at 6, 12 months and yearly thereafter following surgery for long-term morbidities (e.g. frequency of bowel movements, fat malabsorption, micronutrient and protein-calorie malnutrition, need for supplemental nutrition, internal/incisional hernia, and gastro-esophageal reflux).

Study Type

Interventional

Enrollment (Actual)

62

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Quebec
      • Montreal, Quebec, Canada, H3G 1A4
        • McGill University Health Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Participants must meet ALL of the following inclusion criteria:

  • Age ≥18 years and ≤60 years
  • Fulfill criteria for bariatric surgery as coined by National Institutes of Health
  • Give written informed consent

Exclusion Criteria:

Participants who meet any of the following criteria at the time of the baseline visit are excluded from the study:

  • Presence of the following baseline comorbidities:
  • Congestive heart failure (CHF),
  • Chronic kidney disease (CKD) stage 3-5 (or GFR <60 ml/min per 1.73 m2),
  • Inflammatory bowel disease (IBD),
  • Pulmonary hypertension (PHTN),
  • Cirrhosis.
  • Severe gastroesophageal reflux disorder (GERD) +/- presence of any Barrett's disease
  • Individuals who were found by any member of the multidisciplinary team (nutritionist, nurse, psychologist, and surgeon) to be at risk for lack of support and poor compliance (e.g. ≥2 missed appointments without a valid justification)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: BPD-DS
BPD-DS involves creating a sleeve gastrectomy and creation of a Roux-en-Y bypass involving a Roux limb (150cm) which is anastomosed to the transected first-stage of the duodenum and a short common channel (100cm).
Procedure: BPD-DS
Biliopancreatic Diversion with Duodenal Switch
Other Names:
  • Bariatric/metabolic surgery
Experimental: SADI-S
SADI-S involves creating a sleeve gastrectomy but simplifies the bypass part of the BPD-DS by a single anastomosis of a loop of jejunum at 250cm from the ileocecal valve (longer common channel) to the transected first-stage of the duodenum instead of the Roux-en-Y construct.
Procedure: SADI-S
Single Anastomosis Duodeno-ileal Bypass with Sleeve Gastrectomy
Other Names:
  • Bariatric/metabolic surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Short-term Safety Assessment
Time Frame: 30 days
To evaluate feasibility and short-term safety of SADI-S, we will assess operative parameters (procedure time, inadvertent injuries, need for conversion to laparotomy, and transfusion of blood products) and 30-day postoperative adverse events (length of stay, superficial/deep surgical site infection, leak, venous thromboembolism (VTE), need for reintervention and readmission).
30 days
Weight loss
Time Frame: 5 years
%EWL and change in BMI as compared to preoperative reference values
5 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Long-term Morbidity Assessment
Time Frame: 5 years

Postoperatively at 1, 6, 12 months and yearly thereafter for 5 years both groups will be compared for incidence of long-term morbidities including frequency of bowel movements, fat malabsorption, micronutrient and protein-calorie malnutrition, need for supplemental nutrition, internal/incisional herniation, and worsening versus de novo GERD.

At each visit protein (albumin, total protein) and vitamin/micronutrient levels (calcium, magnesium, iron, zinc, copper, selenium, vitamins A/E/D/K/B1/B6/B12) will be monitored using respective blood tests.
5 years
Remission of T2DM
Time Frame: 5 years

The presence of T2DM will be diagnosed according to the American Diabetes Association's current criteria:

  1. HbA1C ≥6.5 percent, OR
  2. FPG ≥126 mg/dL (7.0 mmol/L), OR
  3. 2-hour plasma glucose ≥200 mg/dL (11.1 mmol/L) during an OGTT, OR
  4. In a patient with classic symptoms of hyperglycemia or hyperglycemic crisis, a random plasma glucose ≥200 mg/dL (11.1 mmol/L)
5 years
Resolution/Improvement in other obesity related comorbidities
Time Frame: 5 years
Hypertension, Dyslipidemia, Obstructive sleep apnea, NAFLD/NASH
5 years
Quality of Life Assessment
Time Frame: 5 years
Quality of life status will be assessed using the SF-36 questionnaire at each follow-up visit.
5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

McGill University Health Centre/Research Institute of the McGill University Health Centre

Investigators

  • Principal Investigator: Amin Andalib, MD MSc FRCSC, McGill University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2016

Primary Completion (Actual)

December 31, 2019

Study Completion (Actual)

December 31, 2024

Study Registration Dates

First Submitted

June 2, 2016

First Submitted That Met QC Criteria

June 6, 2016

First Posted (Estimated)

June 7, 2016

Study Record Updates

Last Update Posted (Estimated)

October 1, 2025

Last Update Submitted That Met QC Criteria

September 29, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 15-588 MUHC

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Obesity

Clinical Trials on BPD-DS

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Ecuador

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe