Bariatric Surgery (Sleeve Gastrectomy & Gastric Balloon) in Johannesburg
Bariatric surgery is not about cosmetics — it is a treatment for metabolic disease. For patients with a BMI above 35 (or above 30 with diabetes or hypertension), it produces durable weight loss and often resolves type 2 diabetes entirely.
Performed by Dr Pieter Marais at Johannesburg Surgical Hospital, Randburg, Johannesburg.
What it involves
Dr Marais offers laparoscopic sleeve gastrectomy (the most common bariatric operation in South Africa) and the endoscopic gastric balloon for patients who need a step below surgery. Every patient goes through a full pre-operative assessment with dietitian, physician and psychologist input.
Laparoscopic sleeve gastrectomy removes roughly 75% of the stomach, leaving a narrow tube. It restricts intake and — importantly — reduces ghrelin, the hunger hormone. Expected excess weight loss is 60–70% at one year, with excellent resolution rates for type 2 diabetes, sleep apnoea, and hypertension.
The gastric balloon is a soft silicone balloon inserted endoscopically (no cuts), filled with saline, and left in place for six months. It's a good stepping-stone for patients with BMI 30–35 or those not yet ready for surgery. Typical weight loss is 10–15 kg while it's in place.
Success depends on the wraparound programme, not just the operation. Every patient at the practice sees a dietitian before and after surgery, is assessed by a physician for anaesthetic and metabolic risk, and has psychological support if needed. Long-term follow-up is essential.
When it's indicated
When medical management and lifestyle intervention have not produced sustained results, and the metabolic risk of continuing at current weight outweighs the risk of surgery. That's a conversation, not a checklist.
The approach
Bariatric surgery works. It is also a lifelong commitment. The consultation is honest about both.
Recovery
Sleeve gastrectomy: two nights in hospital. Liquid diet for two weeks, then pureed for two weeks, then soft foods, then normal texture from week six. Return to desk work at two weeks; light exercise from four weeks. Gastric balloon: same-day discharge; three to five days of nausea while adjusting.
Bariatric Surgery FAQ
- Am I a candidate for bariatric surgery?
- Guidelines suggest BMI ≥ 35, or BMI ≥ 30 with a weight-related condition like type 2 diabetes, hypertension, or severe sleep apnoea. Beyond the number, we look at how weight is affecting your life and whether other options have been tried.
- Will medical aid cover it?
- Most South African medical aids cover sleeve gastrectomy for approved indications, subject to pre-authorisation. The practice handles the motivation. Gastric balloon is generally not covered.
- How much weight will I lose?
- Realistic expectation is 60–70% of excess weight in the first year after sleeve gastrectomy. That's typically 30–50 kg for most bariatric patients.
- Is it reversible?
- The sleeve is not reversible — the removed stomach is gone. The gastric balloon is fully reversible (removed at six months). Both need lifelong follow-up.
- What about complications?
- Serious complication rates for sleeve gastrectomy are around 3–5%: bleeding, leak, and reflux being the main concerns. These are lower than the long-term risks of untreated severe obesity. Dr Marais discusses each in detail.
Discuss bariatric surgery with Dr Marais
Send a short enquiry and the practice will be in touch during weekday office hours. Consultations take place at Johannesburg Surgical Hospital.
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