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Trial details imported from

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Registration number
Ethics application status
Date submitted
Date registered
Date last updated

Titles & IDs
Public title
Silastic Ring Gastric Bypass Versus Sleeve Gastrectomy for Type 2 Diabetes Mellitus in Obese Patients
Scientific title
Prospective Randomised Controlled Trial Comparing the Efficacy of Laparoscopic Silastic Ring Roux-en-Y Gastric Bypass Versus Laparoscopic Sleeve Gastrectomy for the Management of Type 2 Diabetes Mellitus in Obese Patients
Secondary ID [1] 0 0
Secondary ID [2] 0 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 2 Diabetes Mellitus 0 0
Obesity 0 0
Condition category
Condition code
Metabolic and Endocrine 0 0 0 0

Study type
Description of intervention(s) / exposure
Treatment: Surgery - Laparoscopic Silastic Ring Roux-en-Y Gastric Bypass
Treatment: Surgery - Laparoscopic Sleeve gastrectomy

Active Comparator: Laparoscopic Silastic Ring Roux-en-Y Gastric Bypass -

Active Comparator: Laparoscopic Sleeve Gastrectomy -

Treatment: Surgery: Laparoscopic Silastic Ring Roux-en-Y Gastric Bypass
An isolated lesser curve-based gastric pouch will be created, with an antecolic antegastric Roux limb fashioned measuring 100 cm in length. The biliopancreatic limb will measure 50cm for all patients. A 6.5cm silastic ring will be placed above the gastrojejunostomy to prevent long term stomal dilatation.

Treatment: Surgery: Laparoscopic Sleeve gastrectomy
Resection of the greater curvature of the stomach from the distal antrum (2cm proximal to pylorus) to the angle of His, using a laparoscopic stapling device over a 36Fr bougie, will be performed to create a lesser curve gastric sleeve

Intervention code [1] 0 0
Treatment: Surgery
Comparator / control treatment
Control group

Primary outcome [1] 0 0
Remission of type 2 diabetes mellitus - COMPLETE:Defined as fasting plasma glucose less than 5.6mmol/L and glycated haemoglobin (HbA1c) less than 6.0% in the abscence of active pharmacologic therapy PARTIAL:Defined as fasting plasma glucose between 5.6 and 6.9mmol/L and glycated haemoglobin (HbA1c) between 6.0 and 6.5% in the abscence of active pharmacologic therapy
Timepoint [1] 0 0
5 years
Secondary outcome [1] 0 0
Weight loss (excess weight loss and actual weight loss)
Timepoint [1] 0 0
5 years
Secondary outcome [2] 0 0
Comorbidity resolution - Measurement of changes in blood pressure, blood lipid profile, obstructive sleep apnoea symptoms and CPAP usage, urinary incontinence frequency, angina severity, reflux symptoms using Visick scale, medication changes
Timepoint [2] 0 0
5 years
Secondary outcome [3] 0 0
Peri/ post-operative morbidity and mortality - For example haemorrhage, thromboembolic events, cardiorespiratory events, marginal ulceration, anastomotic / staple line leak, internal herniation, nutritional deficiencies and mortality
Timepoint [3] 0 0
30-day, In-hospital, 1 year and 5 years
Secondary outcome [4] 0 0
Changes in body composition, resting energy expenditure and bone density - Includes use of dual energy x-ray absorptiometry (DEXA)
Timepoint [4] 0 0
1 year and 5 years
Secondary outcome [5] 0 0
Quality of Life - Using Short Form-36 and Hospital and Anxiety depression scale
Timepoint [5] 0 0
1 year and 5 years

Key inclusion criteria
- Aged 20 to 50 years old

- Body mass index 35-65

- Type 2 diabetes mellitus for at least 6 months

- Suitable for either of the two surgical procedures
Minimum age
20 Years
Maximum age
50 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
- Aged >50 years

- BMI >65

- Type 1 diabetes mellitus or secondary forms of diabetes

- Previous bariatric or oesophagogastric surgery

- Previous small bowel resection

- Severe cardiorespiratory or gastrointestinal disease

- Myocardial infarction or cerebrovascular event within last 6 months

- Malignancy in last 5 years

- Poorly controlled psychiatric disorder

- Contraindication to general anaesthesia

- Current smoker

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Active, not recruiting
Data analysis
Reason for early stopping/withdrawal
Other reasons
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment outside Australia
Country [1] 0 0
New Zealand
State/province [1] 0 0

Funding & Sponsors
Primary sponsor type
North Shore Hospital, New Zealand

Ethics approval
Ethics application status

Brief summary
Type 2 diabetes (T2DM) and obesity are becoming increasingly common in New Zealand (NZ) and
worldwide. Both are associated with a risk of early mortality (death). Whilst weight loss
surgery is known to be effective for weight loss, current research suggests that it may also
be effective in resolving T2DM in around 60-80% of patients, with some no longer requiring
their medication. The mechanism for this remains unclear.

Two main types of weight loss surgery are performed in NZ public hospitals, which include
gastric bypass and sleeve gastrectomy. The gastric bypass is a more complex procedure
compared to the sleeve gastrectomy. Whilst both appear to be effective for weight loss (with
most patients losing more than 60% of their excess weight), it is still not known which one
is better for treating T2DM.

This study will therefore compare which of these two surgical procedures is most effective at
treating T2DM in obese patients, as well as comparing whether there are any differences in
the amount of weight lost, side effects and quality of life.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 0 0
Michael Booth, MBA FRACS
Address 0 0
North Shore Hospital, Auckland, NEW ZEALAND
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for public queries
Name 0 0
Address 0 0
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for scientific queries

No data has been provided for results reporting
Summary results
Other publications