Reuters Health Information: Sleeve gastrectomy may be better than gastric bypass for NASH patients
Sleeve gastrectomy may be better than gastric bypass for NASH patients
Last Updated: 2017-08-18
By Marilynn Larkin
NEW YORK (Reuters Health) - Patients with nonalcoholic steatohepatitis (NASH) may be more vulnerable to early transient deterioration of liver function after Roux-en-Y gastric bypass (RYGB) than after sleeve gastrectomy (SG), researchers in Poland say.
"Morbidly obese patients with suspected nonalcoholic fatty liver disease (NAFLD) or NASH should be given as much attention as patients with diabetes, dyslipidemia or hypertension. The importance of this type of liver injury is increasing, and it is reflected in growing numbers of patients being transplanted for end-stage liver disease related to NASH," Dr. Piotr Kalinowski of the Medical University of Warsaw told Reuters Health.
"Favorable outcomes of many studies may lead us to believe that metabolic surgery is a 'magic bullet' that cures all the conditions in the spectrum of metabolic syndrome," he said by email, "and bypass procedures are regarded as superior to (other strategies) in achieving metabolic improvement."
"I am very enthusiastic about the concept of metabolic surgery, but the outcomes of our study have slightly challenged my beliefs," he said.
Dr. Kalinowski and colleagues compared the effects of SG versus RYGB on liver function in 66 morbidly obese patients (mean age, 45; about 70% women) with NAFLD randomly assigned to one of the two procedures. Intraoperative liver biopsies and liver function tests were done before surgery and after one, six and 12 months. About half of the patients in each group had NASH at baseline.
As reported online August 1 in Annals of Surgery, at one year post-surgery, the percentage of excess weight loss was similar after SG (about 69%) and RYGB (about 63%). Body-mass index (BMI) decreased significantly after both procedures.
At one month post-surgery, the international normalized ratio (INR) increased significantly after RYGB from a mean of 0.98 at baseline to 1.14, compared with a rise from 0.99 to 1.04 after SG. Variables that predicted a change in INR at that point included operation type, NAS of 5 or more, bilirubin levels, BMI, hemoglobin A1C, and dyslipidemia.
One month after RYGB, but not SG, albumin decreased from a mean of 41.2 to 39.0; however, at one year, both INR and albumin returned to baseline.
In the NASH group, SG induced significant improvements at one year in aspartate aminotransferase (32.4 U/L vs. 21.5 U/L), alanine aminotransferase (39.9 U/L vs. 23.8 U/L), gamma-glutamyl transpeptidase (34.3 U/L vs. 24.5 U/L), and lactate dehydrogenase (510.8 U/L vs. 292.4 U/L).
Dr. Kalinowski said, "The transient deterioration of liver function in patients with NASH and metabolic syndrome who underwent RYGB is not an issue we should worry about in the general bariatric population. There is also no mid-term sequela to this early alteration."
"However, it stresses the importance of adequate assessment of liver status in patients at risk of NASH. Matching the procedure to the patient has been the holy grail of bariatric surgery since its beginning, and the puzzle has not been solved yet," he observed. "Our results fill a small gap in the big picture and may help in decision making in patients with advanced NAFLD and NASH and metabolic comorbidities."
"We should now focus on noninvasive methods of liver function assessment that could be employed in the preoperative period as well as in the follow-up," he concluded.
Dr. Scott Friedman, Chief, Division of Liver Diseases at Icahn School of Medicine at Mount Sinai in New York City, said, "The reasons for the advantage (of SG over RYGB) are not entirely clear; however, there were slightly more females in the SG group - females tend to have less advanced NASH if they are premenopausal - and slightly more inflammation in the biopsies in the RYGB group, which would increase liver damage."
"Both groups achieved significant weight loss," he told Reuters Health. "However, follow-up biopsies were not performed to assess the extent of improvement in liver damage after the surgery, which would be the most precise way to assess the benefit to the liver."
The findings "reinforce the overall safety and short-term benefit of bariatric surgery to achieve weight loss in patients with fatty liver disease, provided that there is not yet cirrhosis, which increases the risk of surgery significantly," he said by email.
"Longer-term follow-up of these and other patients undergoing bariatric surgery are essential to assess its overall value in the management of obesity and liver disease," he added. "Moreover, other modalities to achieve weight loss - for example, endoscopic procedures that mimic the effects of bariatric surgery - are an emerging option."
"Most importantly, the findings reinforce previous studies that demonstrate a high risk of significant liver disease (NASH) among patients who are morbidly obese, and the need for clinicians to consider this possibility as they evaluate patients for bariatric surgery," Dr. Friedman concluded.
Ann Surg 2017