Will SIPS replace the gastric bypass?
SIPS: The New Kid on the Bariatric Block-Will a modification of the duodenal switch replace gastric bypass
by Kristina Fiore
Staff Writer, MedPage Today
Duodenal switch is an effective procedure for weight loss, but it currently accounts for less than 5% of all bariatric surgeries due to concerns about technical difficulty, nutritional deficiency, and frequent bowel movements.
But Mitchell Roslin, MD, a bariatric surgeon at Lenox Hill Hospital in New York City, has developed a modification to the procedure and is now pioneering what he calls stomach intestinal pylorus-sparing surgery, or SIPS.
Roslin says SIPS is easier to perform and diminishes the diarrhea and nutritional deficiencies seen with duodenal switch, while also helping patients lose a lot of weight. In the first study of the procedure that Roslin presented at Obesity Week in Boston last month, which enrolled 129 patients between January 2013 and July 2014, there was an average weight loss of 40% at 1 year.
Roslin answered questions from MedPage Today via email about the procedure.
Kristina Fiore: Tell us about the procedure.
Mitchell Roslin, MD: SIPS is a modified duodenal switch, which was given its name by myself and Dr. Daniel Cottam in Utah. It involves the formation of a sleeve gastrectomy that is slightly larger than our usual sleeve, with an attachment placed beneath the pyloric valve, which controls emptying of the stomach into the mid gut, located three meters from the terminal ileum.
Dr. Cottam and I decided to standardize our approach, and now more surgeons are becoming very interested. In Spain, a similar procedure has been done by Juan Antonio Torres and Anders Sanchez. Their sleeve is larger and they bypass more intestine.
Our goal is to find an operation that does not cause abrupt rise and fall of blood glucose, thus preserving the pyloric valve, and not bypass too much intestine and get the complications of short bowel syndrome. Since Dr. Cottam and I have calibrated and standardized the procedure, these variables have been reduced.
Another potential advantage of SIPS is that it does not have a distal anastomosis and avoids a roux limb. Therefore, the intestine is not divided. We believe that this will reduce gastrointestinal symptoms and potentially reduce long-term risk of intestinal obstruction. Also, there is Murphy’s law, and by doing one less attachment, [there is] less [of a] chance for complications.
In the original presentation at Obesity Week, weight loss from SIPS seemed to be similar to that of duodenal switch and 30% greater than sleeve gastrectomy and gastric bypass. One-year weight loss was 40% of body weight, with over 80% of excess weight lost. This is in patients who had an average starting BMI [body mass index] of close to 50. Additionally, there were no obstructions, no marginal ulcers, and no patients that required re-operations from the simplified reconstruction.
SIPS is not a mini gastric bypass because the attachment is after the valve of the stomach and the extra portion of the stomach is resected. Therefore there is no increased risk of bile reflux gastritis. Attraction for SIPS is increasing because surgeons are looking for a solution for sleeve patients who regain weight or have inadequate weight loss, and for efficacy in those with supermorbid obesity.
KF: Are you and your colleague in Utah the first surgeons to use this technique?
MR: I have discussed this for a while. In Spain, a different modification has been done, but I named SIPS and created the size of the sleeve and bowel length. Yes, we are the first to do [the procedure] and accumulate data to be presented, and author a submitted manuscript.
KF: How do the weight loss and safety compare with other procedures?
MR: The complication profile seems favorable to roux-en-Y gastric bypass (RYGB) and other stapling procedures with anastomosis. Early complications seem lower than similar procedures during the first year postsurgery. This is being actively studied in a five-site clinical registry, and the sites include our [two hospitals], Utah, Colorado, and North Carolina. Realize that all cases in this series were done by two experienced surgeons and the registry is being done to better define outcomes.
Interestingly, the weight loss curves were exactly the same in New York and Utah, with smaller standard deviation than gastric bypass or sleeve.
KF: What are your next steps?
MR: Training programs for surgeons are being run and there is incredible demand, far exceeding what can be accommodated. The five-center registry has started. We are also studying continuous glucose monitoring and change in cardiac function following the procedure.
I really think that this is going to be the operation that replaces RYGB in the next several years. Patients will have either sleeve gastrectomy or SIPS.
Roslin reported financial relationships with Covidien, Johnson and Johnson, SurgiQuest, and ValentTx.