me as the BPD, although the Common Channel was allowed to be longer to help reduce malnutrition.
These changes allowed patients to achieve was a reduction in portion sizes that could be eaten in any one setting, and decreased dumping because the pylorus, or muscle located at the end of the stomach, was left intact. Early on, and even sometimes today, the Duodenal Switch was staged, or broken up into two procedures; this was done in order to reduce the risk of doing one big surgery which could take several hours.
The Sleeve Gastrectomy was the first part, followed a few months later by the intestinal bypass. Some patients were happy just with the first part of the procedure- the Sleeve Gastrectomy- and did not want to proceed with the intestinal portion. That is how the stand-alone Vertical Sleeve Gastrectomy started to be used as its own type of weight loss surgery. Of note, the Sleeve Gastrectomy that accompanies the Duodenal Switch is traditionally slightly larger than that of a stand-alone sleeve gastrectomy, in order to allow DS patients to eat a large enough portion of food to get sufficient nutrients (specifically protein) in each day.
The most recent step in this story of evolving surgery was the development of the SADI-S, or Single Anastomosis Duodeno-Ileal bypass with Sleeve Gastrectomy. “Anastomosis” (an-ast-o –MO-sis) is a medical word that means “surgical connection”. When two pieces of intestine, or stomach and intestine, are brought together with staples or sewing, that is called an anastomosis.
As you may know from your research, any time the intestine is cut, and then sewn together with another piece of stomach/intestine, that connection could result in a leak of gastrointestinal contents. Because of the statistical increase for the risk of a leak with each additional connection, the idea behind the SADI-S was to just have ONE anastomosis. Another theoretical advantage is that because fewer connections are required, the surgery could take less time.
In the SADI-S, first a Sleeve Gastrectomy is made, and then a LOOP of distal ileum is attached to the sleeve just after the pylorus. This loop connection is the only intestinal anastomosis that is made, rather than the Y-shaped connection of a traditional Duodenal Switch or Gastric Bypass.
Both the DS and SADI-S are typically performed laparoscopically; occasionally patients may need an open procedure for safety reasons. Both surgeries could potentially be done in stages, by performing the Sleeve Gastrectomy first, and the intestinal portion later. The advantage of two stages is that since the Sleeve is a simpler, faster operation, it is a better choice for patients who are very high risk.
After a period of initial weight loss, it is safer to proceed with the second portion of the procedure. Additionally, in patients who had originally had a Sleeve Gastrectomy, but are still candidates for additional bariatric surgery, converting to a DS or SADI-S may be more straightforward than converting to a Gastric Bypass.
The traditional DS has been performed for a longer period of time – since 1988 as an open procedure, and 1999 as a laparoscopic procedure. This means that we have more long term data on the DS.
The key difference is that only one Intestinal join is made in SADI-S, compared to two in the Duodenal Switch.
With fewer surgical connections in the intestine, the chance of an intestinal leak or blockage is reduced.
In each instance of anastomosis or surgical connection being made, two separate parts of the digestive system are brought together, whether the stomach and/or a part of the intestine. Each connection can have a chance of a leak of gastrointestinal contents, and two connections significantly increase the risk of internal herniation, trapped bowel, and bowel obstruction.
The innovation of SADI-S over the traditional Duodenal Switch is to design the surgery so that only one surgical connection is made. This results in less likelihood of surgical complications.
Weight loss after the DS and SADI-S has been reported to be greater than that of gastric bypa