Major Finding: Omentectomy improved several metabolic parameters after 90 days in patients undergoing Roux-en-Y surgery.
Data Source: Data from 29 nondiabetic adults.
Disclosures: Dr. Dillard said he had no financial conflicts.
SAN DIEGO – Adding omentectomy to Roux-en-Y gastric bypass surgery improved levels of lipids, glucose, and adipokines 90 days after the procedure in nondiabetic patients.
Visceral fat predicts incipient diabetes and cardiovascular disease, but the effect of reducing visceral fat tissue on metabolic risk factors is unknown, said Dr. Troy Dillard of the Oregon Health & Science University in Portland, Ore., at the meeting.
Omentectomy is the surgical removal of the omentum, a fold of visceral fat. To determine the impact of adding omentectomy to gastric bypass surgery, Dr. Dillard and colleagues randomized 29 nondiabetic adults aged 18 years and older to Roux-en-Y alone or Roux-en-Y plus omentectomy. Baseline characteristics including age, gender, and body mass index were similar between the groups.
At 90 days after surgery, body mass index was significantly lower in both groups compared with baseline. But only the omentectomy patients showed significant decreases in fasting glucose, total cholesterol, and very low-density lipoprotein cholesterol, as well as significant increases in their total adiponectin ratios.
Among the omentectomy patients, fasting glucose decreased from 101 mg/dL at baseline to 87 mg/dL after 90 days. Total cholesterol decreased from 191 mg/dL to 163 mg/dL, and VLDL cholesterol decreased from 37 to 21 mg/dL). Triglycerides also decreased significantly, from 179 to 106 mg/dL. Adiponectin increased significantly in the omentectomy group, from 7.2 mcg/mL at baseline to 8.6 mcg/mL after 90 days.
Two patients in the omentectomy group developed gastroenterostomy stenosis and were treated with outpatient endoscopic balloon dilation.
However, any positive effects from the omentectomy seen at 90 days “are likely dwarfed by the metabolic improvements at long-term follow-up conferred by marked weight loss” with the gastric bypass surgery, Dr. Dillard noted.
His study looked at short-term 90-day follow up data, but the long-term clinical benefits of omentectomy remain uncertain, and additional studies are needed.
Long-term follow-up data from other studies suggest that omentectomy is not a beneficial procedure to add to Roux-en-Y gastric bypass, Dr. Dillard said in an interview.
But the type of surgery might make a difference, he noted. “In subjects who are undergoing gastric banding, omentectomy has been shown to be beneficial in long-term follow-up studies. However, more studies are needed in that population to validate that finding” he said.
“At this time, our findings do not indicate that omentectomy should be routinely added to laparoscopic Roux-en-Y gastric bypass, and we look forward to further data to clarify whether subjects undergoing gastric banding will benefit from this procedure.”
The improvements seen on the omentectomy group in Dr. Dillard's study were not explained by differences in total weight loss or inflammatory markers, he said, and the findings support the hypothesis that removing visceral fat tissue might offer metabolic benefits to patients at increased risk for diabetes and heart disease.