Technically it is similar to biliopancreatic diversion with duodenal switch (BPD DS). Difference being duodenum is not disconnected and anastomosis is gastroileal instead of duodenoileal. Gastric sleeve is formed using staplers. Distal ileum (last part of small intestine) is anastomosed to pyloric antrum of gastric sleeve in a Roux en y fashion 250 – 350 cm proximal to ileocecal junction (Roux en y gastroileal anastomosis).
Weight loss after SG TB surgery is mainly because of hormonal and genetic changes. Role of food restriction or malabsorption is secondary. 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 from 1st part of duodenum into distal ileum. There will be more than 200 hormone changes after surgery. 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 ‘fat mass’ to a lower level, resulting in long lasting and effective weight loss. Same hormonal changes are responsible for long lasting type 2 diabetes remission. Ghrelin acts against insulin. As levels of Ghrelin hormone come down, insulin resistance comes down. GLP 1 increases insulin production and sensitivity. Since GLP 1 hormone is increased, insulin production increases and insulin resistance comes down. Partial diversion of biliopancreatic juices also contributes to the metabolic effects of this surgery.
Hormonal and genetic changes responsible for long lasting weight loss and durable diabetes remission are very high in SG TB compared to Sleeve gastrectomy (SG), Roux en y gastric bypass (RYGB), Mini gastric bypass – One anastomosis gastric bypass (MGB – OAGB), Sleeve gastrectomy with loop duodenojejunal bypass (SG LDJB) or Sleeve gastrectomy with duodenojejunal bypass (SG DJB) because bypassed bowel is relatively longer compared to these procedures. So weight loss is more effective & long lasting and diabetes remission is more & durable. Chances of weight regain and diabetes recurrence are very low. Effect of SG TB is comparable to that of Single anastomosis duodenoileal bypass with sleeve (SADI S), Sleeve gastrectomy with loop gastroileal bypass (SG LGIB) and BPD DS. It has several advantages compared to RYGB and MGB – OAGB. There is no ‘at risk’ stomach remnant, calcium and iron deficiency risk is low since some food enters duodenum and jejunum, risk of dumping syndrome is less because of increased gastric inhibitory peptide (GIP) compensating for hypoglycemia. It is technically very simple surgery. Access to biliary tract is maintained. There is no risk of reflux of ileal contents into stomach.
Compared to BPD DS, the risk of protein energy malnutrition, malabsorption and vitamin & mineral deficiencies is low because, it is partial bypass and part of the food enters natural duodenojejunal pathway leading to sufficient absorption of essential nutrients, vitamins and minerals.
There is risk of marginal ulcers and internal hernias. Protein energy malnutrition, malabsorption, foul smelling oily stools, diarrhea and incontinence are high if size of anastomosis is large and length of common channel is less.
LAPAROSCOPIC SLEEVE GASTRECTOMY WITH TRANSIT BIPARTITION
(Laparoscopic SG TB)
(DRAWN BY Dr. V. AMAR)