Technically it is a modification of biliopancreatic diversion with duodenal switch (BPD-DS), the most effective bariatric surgery. But SG – DJB has less risk of mal-absorption compared to BPD – DS. It also can be considered as a combination of sleeve gastrectomy (SG) and roux-en-y gastric bypass (RYGB). It is better operation compared to SG or RYGB since hormonal changes are more and complications are less.
How SG – DJB surgery is performed?
Abdominal cavity is entered through small holes. Upto 80 percent of left side of the stomach is removed and stomach tube (gastric sleeve) of 60 to 120 ml is fashioned over a calibration tube using high quality linear cutter staplers. First part of small bowel (duodenum) is divided 3 to 4 cm below stomach using linear cutter stapler. Middle part of small bowel (jejunum) is divided 50 to 100 cm below the junction of duodenum and jejunum (duodenojejunal flexure) and is joined to the divided first part of duodenum(duodenojejunal anastomosis). Remaining duodenum and this 50 to 100 cm upper jejunum is bypassed (biliopancreatic limb) and doesn’t come in contact with the food. Upper divided end of the jejunum (Lower end of biliopancreatic limb) is joined to the side of small bowel 150 cm below duodenojejunal anastomosis to restore continuity of bowel. All the mesenteric gaps are closed. In this operation, after leaving gastric sleeve, food passes through this 150 cm of small bowel (ailementary limb) to reach the common channel where it mixes with bile and pancreatic juices.
Laparoscopic Sleeve Gastrectomy with Duodenojejunal Bypass (Drawn by Dr. V. Amar)
Why there is long term/ permanent weight loss (fat loss) after SG – DJB surgery?
Weight loss after SG – DJB is not because of food restriction or mal-absorption but because of hormonal and genetic changes. After this operation Ghrelin hormone levels come down as fundus of the stomach is removed. GLP 1, Peptide YY hormone levels increase as food rapidly enters lower small bowel (ileum). Food doesn’t enter the remaining duodenum and upper jejunum. So levels of anti incretin hormones come down. Removal of body of stomach alters several genes involved in energy balance. These hormonal and genetic changes reduce appetite, increase energy expenditure and reset the ‘set point for fat storage’ to a lower level, resulting in long term/ permanent effective weight loss. These changes are better in SG – DJB compared to sleeve gastrectomy (SG) alone.
Please click the following link for more information on how bariatric surgery works – ‘Bariatric surgery’
How type II diabetes is resolved after SG – DJB surgery?
Same hormonal changes are responsible for resolution of type II diabetes. Ghrelin and Anti incretins act against insulin. As levels of these hormones come down, insulin acts well. GLP 1 increases insulin production and reduces insulin resistance. Since GLP 1 is increased, insulin production increases and insulin resistance comes down. These changes result in resolution/ remission of diabetes. Hormonal changes are better in SG – DJB compared to SG or RYGB. So resolution/ remission of diabetes is better.
Please click the following link for more information on how type II diabetes is resolved – ‘Metabolic surgery’
Why SG – DJB is less effective than SG – LDJB?
In SG – DJB, after leaving ‘gastric sleeve’ food has to pass through 150 cm of small bowel (ailementary limb) to reach the common channel where it mixes with bile and pancreatic juices. But in sleeve gastrectomy with loop duodenojejunal bypass (SG – LDJB), once comes out of ‘gastric sleeve’ food directly enters the common channel bypassing entire 200 to 250 cm of the upper small bowel (biliopancreatic limb). In other words, total 200 to 250 cm of upper small bowel doesn’t come in contact with the food. So food reaches lower small bowel early leading to more hormonal changes.
Why SG – DJB is better than RYGB?
In roux-en-y gastric bypass (RYGB), excluded stomach is still present, so if any ulcer or cancer develops in future, in that remnant stomach, it cannot be detected by upper GI endoscopy. Since total duodenum is excluded and doesn’t come in contact with food, risk of calcium and iron deficiency is very high inspite of giving these supplements. There is no valve controlling the food passage from stomach pouch into intestine, so risk of dumping syndrome is high. These risks are either low or absent after SG – DJB. After SG – DJB, upper GI endoscopy can be done, there is no ‘at risk’ stomach remnant, calcium and iron deficiency risk is low since first 4 cm of duodenum is not bypassed and risk of dumping syndrome is less because of intact pylorus controlling food out put into first part of duodenum.
Is SG – DJB surgery risky?
This is a very safe and highly effective operation when performed on suitable candidates after assessing fitness. Major complications like bleeding, leak from the staple line or anastomoses are very rare because of using high end technology such as full HD camera, advanced vessel sealing systems (Harmonic scalpel, Force Triad) and high quality staplers. Minor problems like hair loss, weak look due to rapid weight loss and skin wrinkling can occur but these are temporary. There is vitamin and mineral deficiency risk, even though less compared to RYGB. But these deficiencies can be rectified by giving vitamin and mineral supplements. Calcium and iron deficiencies are less after SG – DJB since first 4 cm of the duodenum is not bypassed.