Obesity Week 2013 RYGB vs LSG: little difference between procedures

despite differences in reoperation rates, remission from type 2 diabetes and EWL, both procedures are safe with acceptably low morbidity and mortality rates.

Four studies comparing laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy have reported that despite differences in reoperation rates, remission from type 2 diabetes and EWL, both procedures are safe with acceptably low morbidity and mortality rates.

The studies were presented at the 30th Annual Meeting for the American Society for Metabolic and Bariatric Surgery (ASMBS) during ObesityWeek 2013, the largest international event focused on the basic science, clinical application and prevention and treatment of obesity. The event was hosted by the ASMBS and The Obesity Society (TOS).

Extreme obesity

The first study, ‘Laparoscopic sleeve gastrectomy or laparoscopic roux-en-y gastric bypass in patients with extreme obesity 30-day morbidity and mortality comparison: a NSQIIP database analysis’, presented by researchers from Yale School of Medicine, compared the short-term safety profile of both procedures in patients with BMI 50-60 using prospectively collected data by the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP

Patients were identified using the 2010 and 2011 ACS-NSQIP data files. For both BMI groups, univariate analyses were conducted to compare the relative frequencies of continuous and categorical outcome variables, respectively, between patients undergoing both procedures.

The primary outcomes included 30-day post-operative mortality, occurrence of major post-operative complications and need for reoperation, and the secondary outcomes included peri-operative variables and 30-day post-operative complications.

The outcomes showed that a total of 6,365 patients with a BMI 50 underwent had either procedure (LSG=1,345, LRGYB=5,020), compared with 1,425 patients with a BMI 60 (LSG=334, LRGYB=1,091). Comorbidities were similar in both procedural groups except for a greater proportion of patients with diabetes in the LRYGB patients (31.4% vs. 27.7%. p=<0.01). No significant differences were found in mortality (0.30% vs. 0.24%, p=0.70) or occurrence of major complications (3.56% vs. 4.33%, p=0.24) between the procedures.

However, patients that underwent LRYGB were found to have a statistically significantly higher rate of return to the operating room within 30-days (p=<0.05). Length of operative time (109.15 min vs. 139.16 min, p=<0.01) and post-operative length of stay (2.25 days vs. 2.49 days, p=<0.01) were significantly lower in patients with BMI 50 who received a LSG. The results were also significant for patients with BMI (117.87 min vs. 145.46 min, p=<0.01; and 2.32 days vs. 2.83 days, p=<0.01).

The researchers concluded that despite its higher technical difficulty, gastric bypass does not have a higher 30-day mortality or a higher incidence of major complications when compared to LSG in patients with BMI 50 and 60. They did note there was a higher risk of reoperation within 30-days after bypass. Nevertheless, they said that both procedures are safe surgical alternatives for weight loss surgery in patients with extreme obesity.

T2DM

A second study entitled, ‘laparoscopic sleeve gastrectomy versus gastric bypass for the treatment of type 2 diabetes mellitus in mild obese patients: 5-year results of a randomized trial,’ presented by Min-Sheng General Hospital, and Ching-Yun University, Taiwan, compared the two procedures in regards to diabetic control and the role of duodenal exclusion.

Thirty diabetic patients with a mean BMI 30(24-34), mean age of 45 (34-58) and mean HbA1C of 10.0 (7.5-15) were randomised to either sleeve gastrectomy (n=30) or bypass (n=30). The primary outcome was remission of T2DM (fasting glucose <126 mg/dl and HbA1c value <6.5% without glycaemic therapy).

The outcomes showed that there were no differences in pre-operative clinical parameters between the two groups. After five years of follow-up, remission of T2DM was achieved by 16 of 22 (72.7%) in the gastric bypass group and 12 of 28 (42.8%) in the sleeve gastrectomy (p<0.05). Gastric bypass patients also lost more weight, achieved a lower level of BMI (23.6 vs. 24.5) and HbA1C (6.1% vs. 6.5%).

However, there was no difference in incretin effects between the groups and both procedures had a GLP-1 effect, with sleeve patients having a better ghrelin reduction, whereas bypass had a better reduction in cholecystokinin and pancreatic polypeptide reducing effects.

“This study demonstrates that participants randomised to gastric bypass were more likely to achieve a durable remission of T2DM,” the researchers concluded. “Duodenum exclusion does play a role in T2DM diabetes treatment.

Procedure comparison

In the third paper entitled, ‘Laparoscopic vertical sleeve gastrectomy vs. Laparoscopic roux-en-y-gastric bypass: single center experience with 2 year follow-up’, researchers from St Luke’s University Hospital and Health Network, Bethlehem, PA, compared the safety and outcome of both procedures at their  institution.

A total of 885 patients were included (547 (62%) underwent bypass and 338 (38%) underwent sleeve). Baseline demographics included age, gender, race and preoperative BMI and the primary outcomes were length of stay, 30-day mortality, serious complication, reoperation and readmission rates and also %EWL at three, six, 12 and 24 months. Secondary outcomes were operative time and blood loss.

From the 885 patients, there were no instances of death. The operative time (80.2 min vs. 104.6 min; p<0.05) and length of stay (29.1 vs. 31hrs; p>0.05) was less for sleeve patients, as was the 30-day complication and reoperation rates, although the difference was not statistically significant. There was no difference in operative blood loss

Bypass patients had a significantly higher readmission rate (5.1% vs. 0.3%; p<0.05), although sleeve patients had a significantly lower %EWL during the follow-up period. In addition,

“Sleeve gastrectomy seems to have a better safety profile in the short term compared to gastric bypass with a significantly lower readmission rate,” the researchers concluded. “However, bypass patients achieve a significantly higher EWL compared to sleeve patients. Randomised clinical trials are needed to better elucidate our findings.”

Elderly patients

In the fourth paper entitled, ‘Short-term outcomes of laparoscopic vertical sleeve gastrectomy and gastric bypass in the elderly; a NSQIP analysis‘, researchers from Dartmouth-Hitchcock Medical Center, assessed the short-term outcomes of the procedures in patients aged 65 years or older.

They identified 1,946 patients from the NSQIP database (sleeve gastrectomy was performed in 155 patients, 8%). There were no statistically significant differences in the presence of cardiac, pulmonary, hepatic or renal comorbidities between the groups.

Diabetes was more frequent in the bypass group (43.2% vs. 53.7%, p=0.013), and vascular comorbidities were more frequent in the sleeve group (21.8% vs. 8.1%, p<0.001). 30-day mortality (0.6% vs. 0.7%), serious complications (5.2% vs. 4.7%) and overall morbidity (9% vs.. 8.2%) were similar.

There was no significant difference in the rate of septic occurrences (1.3% vs. 1.8%, p=1.0), bleeding (2.6% vs. 1.3%, p=0.267), intra-abdominal abscess (0% vs. 0.9%, p=0.632), pulmonary embolism (1.3% vs. 0.6%, p=0.278) or re-operation (3.2% vs. 3.5%, p=0.849) between the groups.

“In elderly patients undergoing laparoscopic bariatric surgery, sleeve gastrectomy is not associated with significantly different 30-day outcomes compared to gastric bypass,” the researchers concluded. “Both procedures are followed by acceptably low morbidity and mortality. For patients aged 65 years and over considering bariatric surgery, both procedures appear to be equally safe.”