Sleeve gastrectomy is the laparoscopic removal of roughly 75-80% of the stomach along its greater curvature, leaving a narrow gastric tube. It is generally offered to people with a body mass index of 40 or above, or between 35 and 40 with a related condition such as type 2 diabetes or sleep apnoea. Patients usually stay in hospital 2-3 days and lose 60-70% of their excess weight within 12-18 months.
Obesity is not simply excess weight; it is the starting point of a chain that runs from type 2 diabetes to sleep apnoea, from joint problems to heart disease. Where diet and exercise fail to produce a lasting result in advanced obesity, surgery is today accepted as the most effective treatment. Sleeve gastrectomy is the most commonly performed bariatric operation worldwide and in Turkey. This article brings together the questions patients seeking sleeve gastrectomy in Mersin ask most often.
What Is Sleeve Gastrectomy?
In sleeve gastrectomy, roughly 75-80 per cent of the stomach along the greater curvature is removed, leaving a narrow tube shaped like a banana. The operation is performed laparoscopically, with a camera and specialised instruments inserted through a few millimetre-sized openings in the abdominal wall.
The effect works in two ways. The first is restrictive: with a smaller stomach, far less food produces a feeling of fullness. The second, no less important, is hormonal: the portion of the stomach removed is the region that secretes most of the hunger hormone ghrelin. This is why patients report not only that they can eat less, but that they want less.
Who Is Eligible?
The internationally accepted criteria are:
- A body mass index (BMI) of 40 or above
- A BMI between 35 and 40 together with at least one obesity-related condition such as type 2 diabetes, hypertension, sleep apnoea, fatty liver disease or advanced joint problems
- Usually an age range of 18 to 65 (selected cases outside this range may also be suitable)
- Failure to achieve lasting weight loss despite diet, exercise and medical treatment
To calculate your BMI, divide your weight in kilograms by the square of your height in metres. For someone 1.70 m tall weighing 110 kg, the BMI is 110 / (1.70 × 1.70) = 38.
Important: These numbers alone do not decide the matter. Age, eating habits, previous weight-loss attempts, psychological readiness and overall health are assessed together. Uncontrolled binge eating disorder, untreated serious psychiatric illness, alcohol or substance dependence, and heart or lung disease that would make surgery unsafe may all mean the operation is postponed.
Preparation Before Surgery
Bariatric surgery is the work of a team, not a single surgeon. The following steps are usually completed beforehand:
- General surgery consultation and the decision to operate
- Endocrinology assessment: thyroid function, insulin resistance, diabetes status
- Nutrition and dietetic counselling: a specific pre-operative diet to reduce fatty liver
- Psychiatric assessment: eating behaviour and readiness to adapt after surgery
- Endoscopy (gastroscopy): to check for hiatal hernia, ulcer or Helicobacter pylori
- Blood tests, chest X-ray, ECG and, where needed, respiratory and cardiology review
Stopping smoking at least two weeks before surgery makes a substantial difference to wound healing and lung complications.
How Is the Operation Performed?
The procedure is carried out under general anaesthesia using the laparoscopic technique. Four or five small openings are usually made in the abdominal wall. The greater curvature of the stomach is mobilised, a calibration tube is placed inside the stomach, and the stomach is divided and shaped over that tube using specialised stapling devices. The removed portion is taken out through one of the openings. The operation takes 1 to 1.5 hours on average.
What Happens Afterwards?
The first days
Patients are usually helped onto their feet on the evening of surgery; early mobilisation is the single most effective way of preventing lung and vascular complications. Once a leak check has been carried out, fluid intake begins. The hospital stay is most often two to three days.
Nutrition timeline
Nutrition advances in stages. The general framework is:
- Weeks 1-2: clear fluids, then a full liquid phase
- Weeks 3-4: pureed, soft foods
- Weeks 5-6: transition to soft solid foods
- From month 2: gradual return to normal solid foods
This timeline varies from patient to patient and is tailored by a dietitian. Three rules apply for life: eat slowly, chew thoroughly, and do not drink with meals.
Weight loss
Weight loss is fastest in the first six months and usually reaches a plateau within 12 to 18 months. On average, 60-70 per cent of excess weight is lost, but this varies markedly with diet and exercise habits. Surgery alone is not enough; a lasting result comes from a change in lifestyle.
Vitamins and follow-up
Vitamin B12, iron, vitamin D, calcium and folic acid supplements must be taken regularly after surgery. Follow-up with blood tests is recommended at 1, 3, 6 and 12 months in the first year, and annually thereafter.
Risks and Possible Complications
In experienced hands sleeve gastrectomy is a safe operation, but like any surgical procedure it carries risks. The main ones are leakage from the staple line, bleeding, venous thromboembolism, stricture and, in the longer term, an increase in reflux symptoms. Serious complication rates in experienced centres are reported in the range of 1-3 per cent. Thorough pre-operative assessment and regular post-operative follow-up are the two factors that most reduce these risks.
Sleeve Gastrectomy or Gastric Bypass?
The same operation is not right for every patient. The general approach can be summarised as follows:
- Sleeve gastrectomy: shorter, technically simpler and, because it does not alter the intestinal arrangement, associated with fewer vitamin absorption problems. Often the first choice in patients without significant reflux.
- Gastric bypass: favoured in patients with type 2 diabetes and significant reflux; its metabolic effect is stronger.
- Gastric balloon and gastric botox: endoscopic procedures offering a temporary solution for patients who have not reached the surgical threshold or who are not suitable for surgery.
The decision is made by weighing BMI, associated conditions, the presence of reflux, eating habits and the patient's own expectations together.
A Bariatric Practice Kept Continuously Up to Date
Op. Dr. Ersan Semerci has made bariatric and metabolic surgery one of the focal points of his career. Over his years in practice he has successfully performed more than 3,000 sleeve gastrectomy and bariatric surgery cases. He keeps his technique current not only through experience but through international training programmes he attends regularly.
- Laparoscopic Bariatric Surgery Course, Acıbadem University Center of Advanced Simulation and Education, Istanbul (2015)
- Gastric Bypass and Beyond Core Training Course, 2nd Bariatric and Metabolic Surgery Congress (2017)
- Surgeon of Excellence Bronze Certification (2018)
- Medtronic Medical Education, Bariatric Re-Do Surgery Training, Bruges, Belgium (2023)
Alongside sleeve gastrectomy, gastric bypass, mini gastric bypass and transit bipartition, he also performs endoscopic gastric balloon and gastric botox procedures. The point patients raise most often in their reviews is that post-operative follow-up continues without interruption, including by phone.
Op. Dr. Ersan Semerci has practised in Mersin since 2010 and currently works at Medicalpark Mersin Hospital. Consultations and operations in Bariatric Surgery are carried out at this hospital. Patients travelling from Mersin and neighbouring provinces can book via WhatsApp.
Book on WhatsAppCan sleeve gastrectomy be reversed?
No. Because the removed portion of the stomach cannot be restored, sleeve gastrectomy is irreversible. If weight loss is insufficient or severe reflux develops, it can be converted to another operation such as gastric bypass; this is known as revision or re-do surgery.
How soon can I return to work?
Office-based workers usually return within one to two weeks. Those doing heavy physical work are advised to wait four to six weeks. The exact period is set by your surgeon according to how you are recovering.
Can the weight come back?
Some of the weight lost in the first 12 to 18 months can be regained if eating habits slip. Regular follow-up, portion control, a protein-focused diet and at least 150 minutes of exercise per week substantially reduce weight regain.
Is sleeve gastrectomy covered by insurance in Turkey?
SGK, the Turkish social security institution, covers bariatric surgery for patients meeting defined criteria. Coverage and required documentation vary by hospital and current regulations, so we recommend confirming before your appointment.
Will I lose hair after surgery?
Temporary hair shedding can occur between months three and six as a result of rapid weight loss. With adequate protein intake and regular use of the recommended supplements, it usually resolves on its own.
Treatment by grade, laser and Doppler-guided methods, recovery after surgery, and how to prevent recurrence.
Answers to the most common questions about appointments, the hospital, treatment scope and surgical experience are in the FAQ section on the home page.
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For Obesity and related symptoms you can book an appointment at Medicalpark Mersin Hospital. Mezitli / Mersin, Turkey, weekdays 09:00-17:00.
WhatsApp: +90 542 236 05 33Disclaimer. This article is provided for general information only. It does not constitute medical advice, diagnosis or a treatment recommendation, and it is not a substitute for examination, diagnosis and treatment by a physician. The content is not tailored to any individual and is not intended as advertising. Do not start, change or stop any treatment on the basis of the information here. Consult your own doctor about any decision concerning your health and see a healthcare provider about your symptoms. The site owner accepts no liability for any consequences arising from use of this content. Last updated: 2026-08-07.