Roux En Y Gastric Bypass
Gastric bypass operations are increasing with the number performed in Australia now surpassing gastricbanding (BariatricSurgical registry data 2016-2017) Gastric bypass is considered by some to be the gold standard that we measure other operations against (asmbs 2005). Roux en Y bypass is the most commonly performed bypass operation performed in Australia.
This operation combines both restriction and metabolicweight loss. Malabsorption is not a major mechanism of weight loss as it is felt that after a few months the gut adaptsand Malabsorption of fat and carbohydrate ceases(C.W Le Roux 2005)Gastric bypassinvolves formation of a small gastric pouch that is directly joined to the proximal (upper) small Bowel. The bypassed stomach, duodenum and top of the jejunum are then joined onto the jejunum lower down with a second anastomosis or Join.There are accepted variations of the Roux en y gastric bypass including banded gastric bypass. This involves adding a fixed band or ring to the gastric pouch to increase the restrictive element of the operation.
First performed in 1967 by Professor E.EMason and Professor Ito. It was used for weight loss after it was observed that people who had partial stomach removal for peptic ulcer lost weight.(Mason E. E 1967). Originally thought to work by Malabsorptionit is now thought to work by more complex means (asmbs 2005). The current theory involves the effects of reduced gastric volume but also a variety of changes to gut hormones that occur with more rapid transit of foodinto the small bowel(C.W Le Roux 2005). Hormones such as Ghrelin, Peptide YY(PYY), GIPand GLP 1 are thought to be important in reducing appetite and increasing satiety (korner 2005).Restriction or decrease in food intake is an important element to the operation and is due to the size of the gastric pouch and also the size of the join between the stomach and small bowel (GastroJejunostomy)
Weight loss is thought to be most durable with gastric bypassin comparison to Gastricband.Gastric sleeve has not been adequately evaluated in long-termseries to make a definitive claim of better or worse durability. A 2017 long term study looking at 12 years of follow up of Gastric bypass patients(Kothari 2017)showed that maximum weight loss occurred at 18 months (79% Excess weight loss) Excess weight loss was still at 57% at 12 years with 83% follow upof patients. A veteran’sstudyin the United Stateswith 31% 10-yearfollow up confirmed a 56.4% Excess weight loss. Biertho et al also showed a 74.6% excess weight loss at 18 months compared with 40.4% with gastric banding(biertho 2003).
Diabetic remission rates arehigh after RYGB. Remission rates are higher than gastric band and Gastric Sleeve. The Stampedetrial (schauer 2017)looked prospectively at matched groups with BMI between 27kg/m2and 43 kg/m2. There was a remission rate of 45% in the gastric bypass cohort compared with
2% in the medically treated cohort. Other conditions that improve significantly after gastric bypass include Hypertension, Dyslipidaemia and gastroesophageal reflux disease.The STAMPEDE trial showed that surgical treatment was alsomore beneficial in these conditions than stand alone medical therapy.
2% in the medically treated cohort. Other conditions that improve significantly after gastric bypass include Hypertension, Dyslipidaemia and gastroesophageal reflux disease.The STAMPEDE trial showed that surgical treatment was alsomore beneficial in these conditions than stand alone medical therapy.
Laparoscopic gastric bypass surgery is considered a relatively safe procedure with a 30-daymortality of .38%-.72% (irene T Ma 2015). This has been confirmed by a number of other studies. Mortality rates have been shown to be higher in low volume centres (asmbs 2005).Mortality rates have dropped dramatically from around 2% in 1993(irene T Ma 2015)to the current levels with the advances in Laparoscopic surgery.
30 day morbidity can be due to complications such as anastomotic leak, bleeding and Pulmonary embolus. Leak rates have been described from .1-5.6%.(Jacobsen 2014)
Long term re operation rates of 3%-20% of patients after RYGB has been described (daellenbach 2011). Complications that may require re operation include anastomotic stricture, Marginal Ulcer, intestinal obstruction and internal hernia.Revision is also possible for pouch dilatation and other anatomical issues that may occur.Dumping and transient Hypo Glycaemia are other side effects of surgery that may require further treatment or surgery.
Regular follow up is recommended for postoperative RYGB patients. Although its mechanism of action is not thought to be by Malabsorption there is some micronutrient Malabsorption due to bypass of the stomach, duodenum and proximal jejunum micronutrient. Vitamin B12, Calcium and Iron. In a recent study 21% of patients developed an iron deficiency in the 1st12 months post RYGB (obinwanne KM 2014). Therefore careful monitoring of patients is expected for life.
Gastric Bypass has evolved into a safe and effective option for patients with obesity and also in the treatment of medical conditions associated for obesity. It should be offered to patients with Morbid obesity but also it can be argued that lower BMI patients with significant medicalissues such as Type 2 Diabetes should be offered RYGB. Life long follow up is recommended