Central Auckland, East Auckland, North Auckland, South Auckland, West Auckland > Private Hospitals & Specialists >

Mr Hisham Hammodat - General, Laparoscopic & Bariatric Surgeon

Private Service Bariatric (Weight Loss) Surgery

Laparoscopic Sleeve Gastrectomy

The sleeve gastrectomy is a purely restrictive operation. In this procedure, the surgeon creates a narrow tube from the stomach and removes the remainder. The surgeon uses metal staples that are similar to stitches and then cuts through the stomach.

The new stomach tube, or pouch, is about one eighth of the size of the original stomach. The route that food takes following a sleeve gastrectomy is the same as it took before surgery.

The sleeve gastrectomy can be performed as a single operation, although it was originally performed as one component of the Duodenal Switch operation. Most people will lose 50% or more of their excess weight. Weight loss is generally quite fast however, because the intestines are not bypassed, most people do not lose as much weight as with the Duodenal Switch or gastric bypass.

Occasionally the procedure will be used as the first stage of a 2-stage procedure, such as Duodenal Switch or gastric bypass. 

Expectations of weight loss

Weight loss occurs quite quickly over the first year following a sleeve gastrectomy.  Most people lose between 50-60% of their excess body weight, although this can vary and some may lose more. Adherence to dietary advice and an exercise programme will result in greater weight loss and better weight maintenance. 


  • Can be performed laparoscopically and avoid open surgery.
  • The amount of food consumed is restricted.
  • Weight loss starts from the time of surgery.
  • Average weight loss is 50-60% of the excess weight.
  • Eliminates the portion of the stomach that produces the hormones that stimulate appetite such as Ghrelin. 
  • The intestines remain intact so food is digested and absorbed as normal.
  • Effective first stage procedure for patients with very high BMI. The surgery can then be followed by conversion to the Duodenal Switch or gastric bypass resulting in further weight loss.


  • The surgery does involve stomach stapling and therefore leaks and other complications related to stapling may occur.
  • Weight loss achieved might not be as much as that following the Duodenal Switch or gastric bypass and there may also be higher risk of weight regain.
  • It is not reversible.

This page was last updated at 4:27PM on January 22, 2020.