AT ENDO 2017
ORLANDO – Roux-en-Y gastric bypass resulted in greater weight loss than sleeve gastrectomy in a study that followed more than 700 patients, an effect that was sustained over time.
However, surgical complications were more common than with sleeve gastrectomy, and patients were more likely to have an extended hospital stay.
The study, conducted by Corey Lager, MD, and his collaborators at the University of Michigan Medical Center, Ann Arbor, looked at 5-year outcomes for 380 patients who had Roux-en-Y gastric bypass (RYGB), compared with those for 336 patients who received sleeve gastrectomy (SG).
Specific outcomes examined included the amount of absolute weight loss and excess body weight loss over the 5-year study period, whether obesity-related comorbidities resolved, and the type and number of complications seen with each procedure.
Sleeve gastrectomy is becoming increasingly popular, even as RYGB and adjustable gastric banding procedures have become more and more rare, Dr. Lager said at the annual meeting of the Endocrine Society. Duodenal switch procedures have continued to represent a very small proportion of surgical weight loss surgeries. Of the four, SG accounted for nearly 80% of the procedures performed in 2013; RYGB, which accounted for about 60% of procedures in 2006, fell to about 30% of procedures by 2013.
The investigators conducted a retrospective analysis of patients undergoing RYGB or SG from January 2008 to November 2013. Patients were seen annually in postoperative follow-up, so the study was able to track body mass index (BMI), weight, excess body weight loss, hemoglobin A1c levels, blood pressure, and serum lipid and vitamin levels over the 5-year period. Additionally, the study captured 30-day postoperative complications for each procedure.
Although about 80% of patients undergoing each procedure were female and baseline lab values and characteristics were similar in many respects, patients undergoing sleeve gastrectomy had higher body weight (mean, 143 kg) and BMI (mean, 50 kg/m2), compared with those who received RYGB (weight, 133 kg; BMI, 47; P less than .001 for both). The average age in both groups was about 45 years.
Sleeve gastrectomy patients were less likely to continue for the full 5 years of follow-up. Of 336 SG patients originally enrolled, 93 had 5-year data. Of the 380 RYGB patients, 188 returned for the 5-year follow-up.
At all time points, the RYGB patients had significantly more total weight loss than the SG patients (P less than .05); the initial weight loss for RYGB patients approached 28% of body weight at year 1, compared with about 23% for the SG patients. By the end of the 5-year period, RYGB patients had maintained about a 24% weight loss, compared with almost 20% for the SG group.
This pattern was mirrored for BMI in each cohort: At year 1, the RYGB patients were down about 14 points, compared with about 12 points for the SG group. By year 5, the difference had narrowed so that each group had lost a mean of between 11 and 12 points from their original BMI, but the difference was still statistically significant (P less than .05).
The final measure of weight loss was excess body weight lost, and again, RYGB patients lost significantly more of their excess body weight at all time points than did the SG patients. At the end of the first year, RYGB had lost more than 65% of their excess body weight, compared with about 48% for the SG patients. By 5 years, the SG patients had regained enough weight that their net excess weight loss was a little less than 40%, while the RYGB patients’ regain put them at about 55% excess weight loss by the end of the study period.
In terms of biomarkers, systolic blood pressure did not differ significantly between the three groups except at study year 3, though the RYGB group had numerically slightly lower systolic blood pressures at all time points. Total cholesterol was lower at 1, 2, 4, and 5 years after surgery for the RYGB group.
Sleeve gastrectomy, as expected, had lower rates of grade I surgical complications, including hemorrhage and infection. Also, the SG patients had fewer postsurgical emergency department visits and a shorter length of stay.
The study results were consistent with those of a 2016 meta-analysis that favored RYGB in terms of excess weight lost, readmission for diabetes-related complications, and resolution of hypertension (Obes Surg. 2016 Feb;26[2]:429-42).
Although this was a large study, it was limited by its retrospective nature and by the lack of randomization, said Dr. Lager. Retaining patients for long-term follow-up was also an issue: Of the original 719 patients, 507 were followed at 3 years and 281 at 5 years, so a significant number weren’t tracked for the full 5 years.
Dr. Lager reported no conflicts of interest, and the study had no outside sources of funding.
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