MADISON, WIS. – Total complication rates are high but comparable over the long term between duodenal switch surgery and Roux-en-Y gastric bypass, according to a propensity matched analysis of 309 superobese patients.
"Duodenal switch is a valid alternative to the Roux-en-Y gastric bypass, especially if significant comorbid illnesses are present, particularly diabetes," Dr. Robert B. Dorman said.
His conclusion is drawn from a study that focused on the long-term outcomes of 178 consecutive patients who underwent duodenal switch (DS) surgery and 139 propensity matched patients undergoing Roux-en-Y gastric bypass (RYGB). In addition to a chart review, the University of Minnesota Bariatric Surgery Outcomes Survey tool was used to prospectively track patients’ weight, comorbid illnesses, adverse outcomes, readmissions, and general health status. Mean follow-up was 3.7 years in the DS group and 6.2 years in the RYGB group.
There were five deaths in the DS group (postop day 38 and months 5, 7, 16, and 66) and three deaths in the RYGB group (postop months 3, 7, and 72), leaving 173 patients and 136 patients, respectively, in the analysis, Dr. Dorman said at the annual meeting of the Central Surgical Association.
Notably, weight loss in the two groups was comparable, decreasing from an average body mass index of 52 kg/m2 to 31 kg/m2 in the DS group and from 51 kg/m2 to 34 kg/m2 in the RYGB group, said Dr. Dorman, a general surgery resident at the University of Minnesota, Minneapolis.
Resolution of type 2 diabetes, hypertension, and hyperlipidemia was greatest among DS patients at 82%, 67%, and 81%, respectively, compared with 64%, 39%, and 55%, respectively, among RYGB patients.
DS patients, however, experienced significantly more loose stools, bloating, and heartburn than did RYGB patients, who had significantly more constipation. Nausea and emesis were comparable between the two groups.
With regard to complications, DS patients were significantly more likely to visit the emergency department (ED) than were RYGB patients (40% vs. 25%; P value less than .01) and to experience hair loss (67% vs. 41%; P less than .01), Dr. Dorman said.
There was also a nonsignificant trend for DS patients to be readmitted more often than RYGB patients (25.4% vs. 23.5%) and to have more gastrointestinal leaks (1.7% vs. 0%), abdominal reoperations (29% vs. 23%), total parenteral nutrition/tube feeds (7.6% vs. 3%), and infusion therapy (28.5% vs. 23.5%). The RYGB patients, however, underwent more endoscopy (22% vs. 14%).
Dr. Dorman said providers should explain to patients the adverse symptoms they can expect following duodenal switch, but noted that the investigators "still feel DS should be limited to surgeons and centers with experience."
Invited discussant Dr. James Wallace, a bariatric and general surgeon from the Medical College of Wisconsin, Milwaukee, described the 40% rate of ED visits in the DS group as "extreme," and questioned the use of nutritional, vitamin, and protein supplementation – particularly in light of the observed hair loss.
"I commend the authors for their excellent surgical outcomes with the duodenal switch – much better than others have reported in the literature – but I’m unconvinced that the incremental improvement in weight loss and resolution of metabolic derangements justifies the increased nutritional risk of the duodenal switch," he said.
Dr. Dorman responded that the ED visits may represent a "knee-jerk reflex" on the part of DS patients when they experience a complication. He added that the university has instituted more frequent checks and phone calls, particularly to high-risk DS patients, and has partnered with their transplant clinic’s infusion center to provide IV fluids. Nutritional support data in this study was insufficient to report on for all patients, but supplementary nutrition is implemented based on factors such as vitamin and albumin levels or difficulty with eating, according to Dr. Dorman.
Invited discussant Dr. Bradley Needleman, director of the bariatric surgery program at Ohio State University in Columbus, said he was most fascinated by the lack of a significant difference in weight loss between the two groups and asked how this finding would influence patient consultations.
Dr. Dorman said a recent case-matched study at their institution also found no significant difference in weight loss between the two procedures (Ann. Surg. 2012;255:287-93), although a recent prospective randomized European study reported that weight loss was significantly greater with duodenal switch surgery than with gastric bypass (Ann. Intern. Med. 2011;155:281-91).