- General anaesthesia via an IV; spinal anaesthesia is not possible.
- Sleeve 45-75 min, mini bypass 60-90 min, bypass 90-120 min.
- Usually a hospital stay of one to a few days.
- Serious complications nationally: 1.4% (DATO 2024).
- Stopping smoking reduces the risk of complications.
What happens during the operation?
You receive general anaesthesia through an IV; Vitalys states that spinal anaesthesia is not possible for this type of operation. The surgeon fills the abdomen with gas to create working space and inserts a camera and instruments through four or five small incisions. The operation is carried out while watching a screen.
In a sleeve about 75 to 80 percent of the stomach is removed with staples. In a bypass a small pouch is created and connected to the small intestine; a mini bypass uses one connection instead of two. At the end the staple lines are tested for leaks, although that test gives no hundred percent guarantee.
Where can I watch a video of the operation?
WeightWorks shows a video explanation by gastrointestinal surgeon Dr Frits Berends on its pages about the gastric bypass and the mini bypass. Vitalys uses short videos in its own app and during information sessions. Prefer videos from Dutch centres: technique and aftercare differ between countries.
What are the risks of the operation?
The risk profile is favourable: in the DATO register, 1.4 percent of Dutch patients had a serious complication in 2024. The most serious early complication is leakage at a staple line. Pain and nausea are the most common, less serious problems in the first days.
Longer-term risks are deficiencies, ulcers at the connection (which is why NSAIDs are forbidden), internal hernia after a bypass (about 1 to 1.5 percent, below 0.12 percent after a mini bypass according to WeightWorks) and reflux after a sleeve. Stopping smoking lowers the risk of complications, thrombosis and reflux.
Risks by phase
Advantages
| Advantage | Explanation |
|---|---|
| Keyhole surgery | small incisions, faster recovery |
| High volume per centre | more than 200 procedures a year |
| National register | every complication recorded in DATO |
| Thrombosis prevention | daily injection after surgery |
Points of attention
| Point of attention | Explanation |
|---|---|
| Right after surgery | pain and nausea |
| First days | staple-line leak, rare but serious |
| First year | deficiencies, dumping after a bypass |
| Years later | internal hernia, ulcers, reflux |
Cost and insurance (2026)
The operation, stay and aftercare are covered by the basic package with a valid indication.
| Item | Amount or arrangement |
|---|---|
| With referral and indication | €385 deductible 2026 |
| Self-pay range | about €7,000-€11,000 |
| WeightWorks all-in 2026 | €10,700 |
| Vitamins afterwards | €10-€15 a month, not covered |
The operation: key figures
| Feature | Value |
|---|---|
| Gastric sleeve | 45-75 minutes |
| Mini gastric bypass | 60-90 minutes |
| Gastric bypass | 90-120 minutes |
| Incisions | 4-5 |
| Serious complications (2024) | 1.4% |
Operation time and features per procedure
| Procedure | Operation time | Intestinal connections |
|---|---|---|
| Gastric sleeve | 45-75 min | none |
| Mini gastric bypass | 60-90 min | 1 |
| Gastric bypass | 90-120 min | 2 |
| SADI (after sleeve) | varies per centre | 1 |
Step by step
- Fasting. You arrive at hospital with an empty stomach.
- Anaesthesia. General anaesthesia via an IV.
- Operation. Keyhole surgery of 45-120 minutes.
- Recovery room. Monitoring of pain, nausea and blood pressure.
- Ward. Stay of one to a few days; first sips of water.
Read next
- Recovery after the operation — week by week
- The treatment pathway — from referral to aftercare
- Types of weight loss surgery — which operation
- Cost and insurance — what you pay
Preparing for the day of surgery
Make sure you do not gain weight between the information session and the operation; Ziekenhuis Rivierenland even asks you to lose a little if possible. Order your WLS vitamins in advance so you can start right after surgery, and bring your CPAP or MRA if you use one for sleep apnoea.
Stop smoking in time, and arrange help at home for the first weeks, because you are not allowed to lift more than 2.5 kilograms.
What you notice right after waking up
In the recovery room you are monitored for pain, nausea and blood pressure. Once you are stable you go back to the ward, where you are encouraged to move soon to prevent thrombosis. On the day of the operation you may only drink clear fluids such as water and tea without sugar.
Frequently asked questions about the operation
A gastric sleeve takes 45 to 75 minutes, a mini gastric bypass 60 to 90 minutes and a classic gastric bypass 90 to 120 minutes. Including anaesthesia and recovery room you are away from the ward for a few hours.
Yes. You receive general anaesthesia through an IV. Spinal anaesthesia is not possible for this operation.
The most serious early complication is a leak at a staple line. Nationally 1.4 percent of patients had a serious complication in 2024. Longer-term risks include deficiencies, ulcers and, after a bypass, an internal hernia.
Four to five small scars where the camera and instruments were inserted. They fade over time.
It reduces the risk of complications around surgery, of thrombosis, heart attack and stroke, and of reflux after surgery.
Usually one to a few days, depending on the procedure, the centre and your recovery. Some hospitals discharge you the day after surgery.
Medically it is keyhole surgery with a favourable risk profile. What makes it demanding is the pathway around it: preparation, a new eating pattern and at least five years of aftercare.
Centres have a medical helpline for problems after surgery, and sometimes a second keyhole operation is needed. Contact them immediately with sudden abdominal pain, fever or shortness of breath.
WeightWorks shows a video explanation by surgeon Dr Frits Berends on its bypass and mini bypass pages, and many centres show images during their information sessions.
The surgical team will usually speak English with you. Ask the centre in advance which information and follow-up materials are available in English.
Call +31 6 38048347 (Mon–Fri 09:00–17:00) or email info@maagverkleining-info.nl. This page is also available in Dutch.
Sources
- DATO Annual Report 2024, DICA
- Vitalys (Rijnstate): FAQ
- WeightWorks: gastric bypass and mini gastric bypass
- Ziekenhuis Rivierenland: patient information
- Weight Clinic: complications
Search terms leading here: weight loss surgery operation, how long does gastric bypass surgery take, bariatric surgery risks Netherlands, weight loss surgery video.
Author: Gijs Bodenstaff. Last reviewed: September 2026.