Sleeve Gastrectomy (SG) is a procedure that permanently reduces the size of the stomach to about 60-80 cc (half a cup). The gastric restriction makes patients lose weight because they eat less. However, it is not only the smaller size of the stomach that creates the early feeling of fullness. It is also the fact that by surgically removing 70% of the stomach along the greater curvature, the procedure takes off a part of the stomach, called fundus, that produces ghrelin, a hormone that is involved in the perception of hunger.
Comparing to other bariatric procedures LSG presents some advantages.
Sleeve Gastrectomy Versus Gastric Band
In laparoscopic adjustable gastric band an inflatable silicone device (band) is placed around the top portion of the stomach creating a small pouch. The band sometimes migrates creating complications. In contrast, SG does not involve placement of any foreign material and therefore no “band migration”-type complications occur.
People who undergo SG usually lose 55% to 70% of their excess weight loss. This is a little higher than the typical weight loss of 60-65% resulting from gastric band. The need for a revisional operation after SG is very low comparing to gastric banding procedures.
Sleeve Gastrectomy Versus RNY or BPD-DS
Being a purely restrictive procedure SG does not change the intestinal anatomy. Food is digested the normal way in the small intestine and therefore no malabsorption of nutrients occurs. In contrast, Roux-en-Y (RNY) and Biliopancreatic Diversion with Duodenal Switch (BPD-DS) have both a restrictive and a considerable malabsorptive nature, which significantly decreases the nutrient absorption capacity of the intestinal tract.
The weight loss results for SG are usually less effective than the 60 to 80% excess weight loss results of RYGB or BPD-DS.
Relative to RNY and BPD-DS, SG carries very low risk at the time of the surgery. Hospitalization after SG surgery is not too lengthy because the surgery is more straightforward.
One important difference between SG and RNY is the preservation of the pyloric valve. This is a sphincter (from the Greek word “sphincter” which means “to bind tight”) muscle that encircles the opening between the stomach and the duodenum allowing food to pass through in a controlled manner. As a result, the person feels full while the food trickles out. In RNY the pyloric valve is removed from the gastrointestinal continuity allowing undigested food to move from the gastric pouch to the small intestine too quickly, a condition called “rapid gastric emptying” or “dumping syndrome.
Another difference between SG and RNY or BPD-DS is that, in SG the upper part of the gastrointestinal tract (esophagus – stomach – duodenum) remains intact allowing doctors to look inside (endoscopy) in the future in order to detect any gastrointestinal and digestive disorders.
In addition, SG does not alter absorption of orally-administered drugs, which may transpire after RNY or BPD-DS.
Sleeve Gastrectomy Versus Vertical Banded Gastroplasty (VBG)
Both SG and VBG are restrictive procedures that create a small stomach pouch. While in SG part of the stomach is resected, in VBD the stomach is compartmentalized with the help of a plastic band and staples. However, as early as 1999 studies, showed that the long term results of VBG are discouraging. Re-operation after VBG is usually high, ranging from 14% to 43%, because of inadequate weight loss, disruption of the staple-line, food intolerance and stenosis of the banded stoma.