Bariatric & metabolic surgery
Obesity is a chronic disease, not a lack of willpower. Surgery is the treatment with the most durable results.
Your surgeon: Stefanos Lazaridis MD, FRCS, Director, 11th Surgical Clinic for Obesity & Reflux, Metropolitan General, Athens · formerly NHS Consultant in Upper GI & Bariatric Surgery, London
Short answer
Weight loss surgery (bariatric surgery) changes the size of the stomach and, in some operations, the route food takes through the gut. It reduces hunger and portion size and improves conditions such as type 2 diabetes, high blood pressure, sleep apnoea and reflux. The two main operations are the gastric sleeve and the gastric bypass. Both are done by keyhole (laparoscopic) surgery.
Who it is for
International guidelines recommend weight loss surgery for adults with:
The numbers are only the starting point. The decision also depends on your overall health, your readiness for change and whether long-term follow-up is possible.
The operations
There is no single best operation. The right one depends on your weight, your eating pattern, reflux, diabetes and your medical history.
Most common
About 80% of the stomach is removed, leaving a narrow tube. Fewer hunger hormones, smaller meals. No rerouting of the gut.
Gold standard
A small stomach pouch joined to the small intestine. Somewhat greater long-term weight loss, and the better choice when reflux or diabetes is present.
After a previous operation
For weight regain, reflux or other problems after a sleeve, band or bypass done elsewhere.
Results
Results are given as the percentage of excess weight lost: the weight above a healthy BMI of 25.
| Excess weight lost | Gastric sleeve | Gastric bypass |
|---|---|---|
| 5 years (SM-BOSS) | 61% | 68% |
| 10 years (SLEEVEPASS) | 44% | 51% |
Sources: Salminen P. et al., SLEEVEPASS 10-year results, JAMA Surgery 2022. Peterli R. et al., SM-BOSS 5-year results, JAMA 2018. Figures refer to the percentage of excess weight lost.
The process
In person or by video. History, goals, previous attempts and a first opinion on whether surgery is right for you.
Blood tests, gastroscopy and assessments by the dietitian and, where needed, other specialists.
Keyhole surgery at Metropolitan General, Athens. About 24 hours in hospital after a sleeve, 48 hours after a bypass.
Diet stages, supplements and regular reviews, in person or remotely, for years after surgery.
The team
Weight loss and reflux surgery work best when the same experienced team prepares you and follows you up. I work with a stable team of specialists:
2
Gastroscopy, reflux and oesophageal function testing before and after surgery.
2
Assessment of breathing and sleep apnoea before surgery.
1
Diabetes, hormones and metabolic care.
1
Specialised in weight loss surgery: preparation, diet stages and long-term nutrition.
1
Specialised in weight loss surgery: assessment and support before and after the operation.
Travelling for surgery
Length of stay, flying home, follow-up and emergencies: information for international patients.
We start with a video call. You send your history and any tests, and we decide together whether surgery makes sense before you book a flight.
With your consent I send a full report to your GP or specialist at home. The specialist follow-up stays with us.
Regular follow-up by video call and email, with a clear plan for blood tests and supplements that you can arrange locally.
Questions
Modern laparoscopic bariatric surgery has a safety profile similar to other common abdominal operations, such as gallbladder removal. Careful preparation and an experienced team keep the risk low. I will discuss your own risks in detail at the consultation.
GLP-1 medicines can help many people, but weight usually returns when they are stopped. Surgery gives durable results without lifelong injections. For some patients the two are combined.
Yes, after both a sleeve and a bypass. UK guidelines (BOMSS) recommend lifelong daily vitamin and mineral supplements and at least yearly blood tests. The bypass needs a broader set of supplements.
At least seven days after surgery, unless you live a short trip away. The hospital stay itself is about 24 hours after a sleeve and 48 hours after a bypass; the rest of the week lets us check your recovery before you travel.
Next step
Send us your details and I will contact you for a first conversation, by phone or video call.