Accuracy, reproducibility of liver disease assessment poor in morbidly obese patients

WASHINGTON — Although morbidly obese patients with non-alcoholic fatty liver disease face a higher risk of surgical and anaesthesiological complications related to advanced liver fibrosis, accurate non-invasive assessment of hepatic fibrosis before surgery has proven difficult, a speaker said here.

“The methods are poorly feasible and not reliable in these patients,” Thomas Karlas, MD, of Leipzig University Medical Center, said at The Liver Meeting.

Researchers analyzed 41 patients – 28 female, median age 46 – with a median body-mass index of 47. Each was examined via transient elastography (TE) or acoustic radiation force impulse (ARFI) imaging 14 days before bariatric surgery, after which the patients were randomly assigned to one of two 14-day, low-energy diets intended to reduce visceral adipose tissue and liver volume.

Thomas Karlas

The patients then underwent TE or ARFI again the day before surgery. Results were compared using intraoperative liver biopsies, while adipose tissue and liver volumes were assessed by MRI, Karlas said.

Both methods failed to identify the cirrhotic patient, he said. Valid TE measurements at 14 days before surgery and 1 day before were available in only 34% of patients using the XL probe, meant for obese patients, and only in 10% using the M probe. While serial ARFI data were available in 83% of the cases, less than 10% fulfilled the interquartile range criterion.

“Assessment of liver disease prior to bariatric surgery remains important,” he said, but clinicians “cannot rely on ultrasound based noninvasive [methods.]”

Disclosure: Karlas received travel expenses from Echosens.

For more information:

Karlas T #556: Poor performance and diagnostic accuracy of preoperative transient elastography and ARFI imaging in morbidly obese bariatric patients. Presented at: The Liver Meeting 2013; Nov. 1-5, Washington.