Bariatric Surgery (Gastric Bypass)NCT07483957
Linear vs. Circular Stapled Gastrojejunal Anastomosis in Bariatric Laparoscopic Gastric Bypass Surgery in Switzerland
An observational study of Bariatric Surgery (Gastric Bypass), run by Cantonal Hospital of St. Gallen at 1 site in Switzerland.
Trial summary
Bariatric surgery has become one of the preferred options in treatment of severe obesity and its comorbidities in the Western world. In Switzerland, the approximate 5000 annual bariatric operations are performed exclusively in centres certified by the "Swiss Society of Study of Morbid Obesity and Metabolic Disorders… Read more about this study
- Who is it for?
- Ages 20 years and older
- Conditions the study is for
- Bariatric Surgery (Gastric Bypass)
- What is being tested?
- Linear anastomosis and Circular anastomosis
- Type of treatment
- Surgery or procedure
- How many people
- 21,375 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Jan 2015to 15 May 2025
- How long will I take part?
- 90 Days
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 years and older
- All sexes
- Adult, Older adult
Study population: All patients with gastric bypass surgery in Switzerland between 2015 and 2022
Who may be able to join
- Elective laparoscopic Roux-en-Y gastric bypass
Who cannot join
- Incomplete documentation
- Age under 20 years
- Other hospitals than general or surgical hospitals
- Omega-loop gastric bypass
- Emergency admission
- No stapler coded
- Open access
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
HOCH Health Ostschweiz, Kantonsspital St.Gallen
Sankt Gallen, 9000
About this study
Official title: Linear vs. Circular Stapled Gastrojejunal Anastomosis in Bariatric Laparoscopic Gastric Bypass Surgery in Switzerland: A Retrospective National Registry Study From 2015 to 2022.
Bariatric surgery has become one of the preferred options in treatment of severe obesity and its comorbidities in the Western world. In Switzerland, the approximate 5000 annual bariatric operations are performed exclusively in centres certified by the "Swiss Society of Study of Morbid Obesity and Metabolic Disorders (SMOB)". Among the different bariatric surgical procedures, the laparoscopic gastric bypass remains one of the most frequently performed operations. A critical step of this operation is the creation of the gastrojejunal anastomosis. This can be done using either a linear or a circular stapler. The optimal method continues to be discussed in current academic research. The linear anastomosis technique seems to be more feasible, uses smaller incisions and is therefore faster performed. The circular anastomosis technique benefits from a standardised diameter of the anastomosis with consecutive higher reproducibility. No difference in long-term weight loss have been described for these two techniques until today. The linear technique has been linked to marginal ulcers, while the circular technique has been associated with higher rates of stenosis and incisional hernia. The associations with other long-term adverse events such as internal hernias remain under discussion. However, according to several international analyses, the linear technique seems to have favourable short-term outcomes with shorter operation time and lower rates of wound complications and postoperative bleeding. Both techniques are used in Switzerland but Swiss national data on this topic is scarce. Given the high annual case volume of bariatric surgery in Switzerland and the inconsistent international evidence, a systematic comparison of these two techniques is of relevance.
This retrospective registry study provides Swiss national data on short-term postoperative outcomes after elective laparoscopic Roux-en-Y gastric bypass from 2015 to 2022. It aims to compare the linear vs. circular gastrojejunal anastomosis in terms of postoperative short-term postoperative, reoperation rate, and length of hospital stay.
- Conditions
- Bariatric Surgery (Gastric Bypass)
- Being tested
- Linear anastomosis, Circular anastomosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Linear anastomosisProcedure or surgery
A linear stapled anastomosis was selected based on the Swiss Classification of Operations (CHOP) code 00.9A.13 or 00.9A.14.
Circular anastomosisProcedure or surgery
A circular stapled anastomosis was selected based on the Swiss Classification of Operations (CHOP) code 00.9A.11 or 00.9A.12.
| Study group | Role | What they receive |
|---|---|---|
| Linear | Elective laparoscopic Roux-en-Y gastric bypass with linear gastrojejunal anastomsis Receives: Procedure: Linear anastomosis | |
| Circular | Elective laparoscopic Roux-en-Y gastric bypass with circular gastrojejunal anastomsis Receives: Procedure: Circular anastomosis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Overall complications
Measured: Periprocedural
Secondary outcomes (7)
Individual complications
International Statistical Classification of Diseases and Related Health Problems 10th Revision codes
Myocardial infarction (I21, I22) I21, I22 Cardiac arrest I46 Arterial fibrillation I48 DVT and/or PE I26.0, I26.9, I80.2 Pneumonia J13-18, J85.1 Pleural effusion J90, J91 Atelectasis J98.1 Aspiration J69.0, J69.8, J95.4 Pulmonary insufficiency J95.1, J95.2, J95.3, J96 ARDS J80 Acute kidney injury N17, N19 Urinary tract infection N10, N30.0, N30.9, N39.0 Urinary retention R33 Anastomotic leakage K91.83 Gastrointestinal ulcer K25, K28 Peritonitis / abscess K65 Delayed gastric emptying K31.88 Ileus K56, K91.3 Bleeding K81.0, S36.81 Shock T81.1 Wound dehiscence T81.3 SSI T81.4, T89.02, L08.9 Intraoperative injury T81.2 Intraoperative retained foreign body T81.5, T81.6 Other complications J95.8, J95.9, K91.88, K91.9, T81.8, T81.9
Measured: Periprocedural
Reoperation
A reoperation was selected based on the Swiss Classification of Operations (CHOP) code 00.99.10.
Measured: Periprocedural
Length of hospital stay
Length of hospital stay was assessed at the 50th percentile (typical postoperative course) and the 90th percentile (prolonged postoperative course).
Measured: up to 4 weeks
Time trend age
Time trend of annual mean age (years)
Measured: Between 2015 and 2022
Time trend CCI
Time trend of annual mean Charlson Comorbidity Index (CCI)
Measured: Between 2015 and 2022
Time trend insurance
Time trend of annual percentage of private insurance
Measured: Between 2015 and 2022
Time trend access
Time trend of annual percentage of robotic access
Measured: Between 2015 and 2022
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Mar 2026
- Study start1 Jan 2015
- Primary completion31 Dec 2022
- Study completion15 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Bariatric Surgery (Gastric Bypass)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 21,375 participants (actual)
- Target duration
- 90 Days
Sponsor and investigators
- Lead sponsor
- Cantonal Hospital of St. Gallen
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yanic Ammann, Cantonal Hospital of St. Gallen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07483957
- Sponsor's protocol ID
- RYGB linear vs. circular
- Status last verified
- Mar 2026
- First submitted
- 5 Mar 2026
- Last updated
- 19 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Ammann Y, Warschkow R, Klein M, Schneider R, Muller B, Lisarelli L, Tarantino I, Folie P. Linear versus Circular Stapled Gastrojejunostomy in Minimally Invasive Roux-en-Y Gastric Bypass: A Nationwide Swiss Administrative Database Study (2015-2022). Obes Surg. 2026 Oct 16. doi: 10.1007/s11695-026-08982-x. Online ahead of print.
PubMed 42886429
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Linear vs. Circular Stapled Gastrojejunal Anastomosis in Bariatric Laparoscopic Gastric Bypass Surgery in Switzerland: A Retrospective National Registry Study From 2015 to 2022.
- ClinicalTrials.gov ID
- NCT07483957
- Acronym / sponsor ID
- RYGB linear vs. circular
- Conditions
- Bariatric Surgery (Gastric Bypass)
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 21,375 participants (actual)
- Lead sponsor
- Cantonal Hospital of St. GallenUniversity, hospital or other
- Study start
- 1 Jan 2015 (actual)
- Primary completion
- 31 Dec 2022 (actual)
- Study completion
- 15 May 2025 (actual)
- First posted
- 19 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Bariatric surgery has become one of the preferred options in treatment of severe obesity and its comorbidities in the Western world. In Switzerland, the approximate 5000 annual bariatric operations are performed exclusively in centres certified by the "Swiss Society of Study of Morbid Obesity and Metabolic Disorders (SMOB)". Among the different bariatric surgical procedures, the laparoscopic gastric bypass remains one of the most frequently performed operations. A critical step of this operation is the creation of the gastrojejunal anastomosis. This can be done using either a linear or a circular stapler. The optimal method continues to be discussed in current academic research. The linear anastomosis technique seems to be more feasible, uses smaller incisions and is therefore faster performed. The circular anastomosis technique benefits from a standardised diameter of the anastomosis with consecutive higher reproducibility. No difference in long-term weight loss have been described for these two techniques until today. The linear technique has been linked to marginal ulcers, while the circular technique has been associated with higher rates of stenosis and incisional hernia. The associations with other long-term adverse events such as internal hernias remain under discussion. However, according to several international analyses, the linear technique seems to have favourable short-term outcomes with shorter operation time and lower rates of wound complications and postoperative bleeding. Both techniques are used in Switzerland but Swiss national data on this topic is scarce. Given the high annual case volume of bariatric surgery in Switzerland and the inconsistent international evidence, a systematic comparison of these two techniques is of relevance.
This retrospective registry study provides Swiss national data on short-term postoperative outcomes after elective laparoscopic Roux-en-Y gastric bypass from 2015 to 2022. It aims to compare the linear vs. circular gastrojejunal anastomosis in terms of postoperative short-term postoperative, reoperation rate, and length of hospital stay.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 90 Days
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Linear | – | Procedure: Linear anastomosisElective laparoscopic Roux-en-Y gastric bypass with linear gastrojejunal anastomsis |
| Circular | – | Procedure: Circular anastomosisElective laparoscopic Roux-en-Y gastric bypass with circular gastrojejunal anastomsis |
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- All patients with gastric bypass surgery in Switzerland between 2015 and 2022
Key inclusion criteria (1 listed)
- Elective laparoscopic Roux-en-Y gastric bypass
Key exclusion criteria (7 listed)
- Incomplete documentation
- Age under 20 years
- Other hospitals than general or surgical hospitals
- Omega-loop gastric bypass
- Emergency admission
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Linear anastomosisA linear stapled anastomosis was selected based on the Swiss Classification of Operations (CHOP) code 00.9A.13 or 00.9A.14. | Procedure or surgery | Linear |
| Circular anastomosisA circular stapled anastomosis was selected based on the Swiss Classification of Operations (CHOP) code 00.9A.11 or 00.9A.12. | Procedure or surgery | Circular |
Primary outcome
Overall complications
Time frame: Periprocedural
7 secondary outcomes
Individual complications
Time frame: Periprocedural
Reoperation
Time frame: Periprocedural
Length of hospital stay
Time frame: up to 4 weeks
Time trend age
Time frame: Between 2015 and 2022
Time trend CCI
Time frame: Between 2015 and 2022
Time trend insurance
Time frame: Between 2015 and 2022
Time trend access
Time frame: Between 2015 and 2022
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Mar 2026.
- Derived from this study: PubMed 42886429Ammann Y, Warschkow R, Klein M, Schneider R, Muller B, Lisarelli L, Tarantino I, Folie P. Linear versus Circular Stapled Gastrojejunostomy in Minimally Invasive Roux-en-Y Gastric Bypass: A Nationwide Swiss Administrative Database Study (2015-2022). Obes Surg. 2026 Oct 16. doi: 10.1007/s11695-026-08982-x. Online ahead of print.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Bariatric Surgery (Gastric Bypass), run by Cantonal Hospital of St. Gallen at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Overall complications (time frame: Periprocedural). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07483957, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Mar 2026.