Struggling with obesity and looking for a permanent, proven solution? Sleeve gastrectomy — also known as VSG or gastric sleeve surgery — is one of the safest and most effective weight loss surgeries available today. At Slim Expert in Lahore, it is performed by Prof. Maaz Ul Hassan, Pakistan’s most experienced bariatric surgeon, with over 12,000 surgeries and 28 years of specialized expertise behind him.
This page covers everything you need to know about sleeve gastrectomy in Pakistan — what it is, how it works, the full procedure process, expected results, recovery, risks, cost, and how to get started.
What is sleeve gastrectomy (VSG)?
Sleeve gastrectomy is a permanent, minimally invasive weight loss surgery in which 75 to 80 percent of the stomach is surgically removed. The remaining portion of the stomach is shaped into a narrow tube — or sleeve — roughly the size and shape of a banana. This dramatically limits the amount of food you can eat at one time and significantly reduces hunger.
The procedure permanently alters the stomach structure, so unlike a gastric band, there is nothing to adjust, fill, or remove later. Because the part of the stomach that produces ghrelin — the hormone responsible for hunger — is removed during the operation, most patients experience a substantial and lasting reduction in appetite. This is what makes VSG so effective: it works on both restriction and hunger control at the same time.
Sleeve gastrectomy is performed laparoscopically, meaning through small keyhole incisions rather than a large open cut. This results in a faster recovery, less postoperative pain, smaller scars, and a significantly lower risk of complications compared to open surgery.
How does sleeve gastrectomy work?
Sleeve gastrectomy produces weight loss through two distinct and well-established mechanisms working together:
1. Physical restriction
After surgery, your stomach can hold only 100 to 150 ml of food at a time — compared to 900 to 1,500 ml in a normal stomach. This means you feel full after eating a very small amount. Portion sizes reduce dramatically and calorie intake falls naturally, without requiring willpower alone.
2. Hormonal change
The section of stomach removed during VSG includes the fundus — the part that produces the majority of ghrelin, the hormone that signals hunger to your brain. With far less ghrelin circulating in your body, you feel genuinely less hungry throughout the day. This hormonal shift is one of the key reasons VSG delivers better long-term results than purely mechanical procedures such as gastric banding.
Together, restriction and reduced hunger allow patients to consistently eat far less, resulting in sustained, significant weight loss over time — without feeling deprived or constantly fighting hunger.
The sleeve gastrectomy procedure — what to expect
Pre-operative assessment (2 to 4 weeks before surgery)
Before your surgery is scheduled, Prof. Maaz Ul Hassan conducts a thorough medical evaluation to confirm your suitability for VSG and minimize risk. This assessment includes:
- Full blood panel: complete blood count, liver function, kidney function, thyroid, HbA1c, lipid profile, and coagulation screen
- Upper GI endoscopy to assess the stomach and oesophagus for ulcers, polyps, or H. pylori infection
- Cardiac evaluation including ECG and, if required, echocardiogram
- Pulmonary function testing for patients with sleep apnoea or respiratory issues
- Nutritional assessment and dietary counselling with our specialist dietitian
- Psychological evaluation to assess readiness and establish realistic expectations
If H. pylori infection is detected, it is treated and cleared before surgery proceeds. Any other findings are addressed to optimize your health before the operation.
The surgery itself (60 to 90 minutes)
Sleeve gastrectomy is performed under general anaesthesia in a fully equipped operating theatre. Prof. Maaz uses a laparoscopic approach throughout — five small incisions of approximately 1 cm each are made in the abdomen. Using a surgical stapler, approximately 75 to 80 percent of the stomach is divided and removed, leaving a narrow sleeve approximately 15 cm long. The staple line is carefully reinforced to prevent leakage. The entire operation typically takes between 60 and 90 minutes.
In-hospital recovery
Following surgery, you will be moved to a monitored recovery ward. Most patients spend 2 to 3 nights in hospital. During this time:
- Pain is managed with intravenous medication — most patients report discomfort rather than severe pain
- You will begin sipping clear fluids within 24 hours of surgery
- A physiotherapist will guide you through gentle breathing exercises and early mobilization to reduce the risk of blood clots
- A leak test is performed before discharge to confirm the staple line is secure
- Blood thinning injections are administered to prevent deep vein thrombosis
Sleeve gastrectomy recovery — week-by-week
- Week 1: Rest at home. Clear fluids only — water, broth, diluted juice. Mild soreness around incision sites. Short gentle walks encouraged. No driving.
- Weeks 2–3: Progress to full liquids: protein shakes, yoghurt, blended soups. Light desk work can resume.
- Weeks 4–6: Soft and pureed foods introduced. Most patients feel significantly better. Walking duration increases.
- Weeks 6–8: Transition to soft solid foods. Most patients return to full-time work. Exercise intensity can begin to increase.
- 3 months: Normal solid foods reintroduced gradually. Weight loss is rapid and visible.
- 6–12 months: Peak weight loss period. Lifestyle habits well established. Consistent exercise routine.
Diet progression after VSG
- Clear liquids (days 1–7): water, clear broth, diluted juice, sugar-free drinks
- Full liquids (weeks 2–3): protein shakes, smooth yoghurt, pureed soups, milk
- Pureed and soft foods (weeks 4–6): scrambled eggs, soft fish, mashed vegetables, cottage cheese
- Soft solids (weeks 7–8): well-cooked vegetables, soft fruits, ground meat, soft bread
- Normal foods (month 3 onwards): most foods tolerated — small portions, chewed thoroughly, eaten slowly
Expected results from sleeve gastrectomy
- Excess weight loss: 60–70% within 12 to 18 months
- Total body weight loss: 25–35% on average
- Type 2 diabetes: 60–80% of patients experience significant improvement or full remission
- Hypertension: 50–70% reduction in blood pressure medication within 12 months
- Sleep apnoea: Significant improvement or resolution in most patients
- Joint pain: Marked reduction in knee, hip, and back pain as weight decreases
- 5-year maintenance: Most patients maintain 50–60% excess weight loss with correct lifestyle habits
Risks and potential complications
Short-term risks (within 30 days)
- Staple line leak: the most serious short-term complication, occurring in less than 1% of cases. Treatable if detected early.
- Bleeding: rare; usually resolves without intervention.
- Blood clots (DVT/PE): prevented through blood thinning medication, compression stockings, and early mobilization.
- Infection: incision site infections are uncommon and treated with antibiotics.
Long-term considerations
- GERD (acid reflux): some patients develop or experience worsening of acid reflux. Patients with significant pre-existing GERD may be advised to consider gastric bypass instead.
- Nutritional deficiencies: lifelong supplementation of vitamin B12, vitamin D, calcium, iron, and a multivitamin is essential.
- Weight regain: a small number of patients regain weight, usually due to dietary habits. Ongoing follow-up significantly reduces this risk.
Why choose Prof. Maaz Ul Hassan?
- 12,000+ bariatric and laparoscopic surgeries — highest volume of any bariatric surgeon in Pakistan
- 28+ years of exclusive specialization in obesity, diabetes, and metabolic surgery
- Pioneer of the MMRYGB — the Maaz Modification of Roux-en-Y Gastric Bypass — recognized internationally
- Professor of Surgery at Shalamar Institute of Health Sciences, Lahore
- International training: FCPS (Pakistan), FLS (USA), Diploma in Laparoscopic Surgery (France), Fellowship in Bariatric and Minimally Invasive Surgery
- Operated on Pakistan’s heaviest patient at 380 kg (now 140 kg) and the world’s heaviest child at 200 kg (now 100 kg)
Frequently Asked Questions
How long does sleeve gastrectomy surgery take?
The operation itself takes between 60 and 90 minutes under general anaesthesia. Most patients spend 2 to 3 nights before discharge.
Is sleeve gastrectomy painful?
Most patients report manageable discomfort rather than severe pain. Pain is well-controlled with medication during your hospital stay, and most patients are comfortable on oral pain relief alone by discharge.
How soon can I return to work after VSG?
For desk-based or office work, most patients return within 2 weeks. Those with physically demanding jobs typically require 4 to 6 weeks.
How much weight will I lose after gastric sleeve surgery?
Most patients lose 60 to 70 percent of their excess body weight within 12 to 18 months. Total body weight typically reduces by 25 to 35 percent.
Is sleeve gastrectomy available in Lahore?
Yes. Prof. Maaz Ul Hassan performs sleeve gastrectomy at Shalamar Hospital and his dedicated clinic in Lahore. Patients travel from across Pakistan and internationally for his expertise.
Ready to take the first step? Book your consultation
If you are considering sleeve gastrectomy and want to speak directly with Pakistan’s most experienced bariatric surgeon, book a consultation with Prof. Maaz Ul Hassan today. The consultation includes a full review of your medical history, an honest assessment of your suitability, and a clear explanation of all your options — with no pressure and no obligation.
Call / WhatsApp: 0305-9738995
Location: Lahore, Punjab, Pakistan — patients welcomed from all cities. Video consultations available.
Book a consultation: Patient portal · +92 329 166 4350