Stenting for bile duct cancer increases liver volume

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Endoscopic stenting for bile duct cancer increases liver volume regardless of the stent location, according to new research from South Korea.

In hilar and distal bile duct cancer, metal stents markedly increased liver volume within four to eight weeks, the authors reported online March 28 in Gastrointestinal Endoscopy.

"This study broached a new area regarding liver volume," Dr. V. Raman Muthusamy of the David Geffen School of Medicine at UCLA in Los Angeles told Reuters Health. "The purpose of endoscopic stenting in bile duct cancer has been to relieve obstruction and avoid infection. This study indicates that a third potential role for stenting may be to reduce liver atrophy or even promote regeneration." Dr. Muthusamy wasn't involved in the study.

The findings, admittedly from a highly selected group of patients, "are certainly intriguing," said Dr. Carlos Corvera of the University of California, San Francisco, who also wasn't involved in the study.

In an email to Reuters Health, Dr. Corvera added, "They hypothesize that this effect on liver regeneration can be explained by the effectiveness of biliary drainage leading to recovery and hepatocyte proliferation following decompression."

The authors say liver volume assessment should be considered a useful tool to evaluate stent efficacy. Asked if he agrees, Dr. Corvera said, "I agree with the authors that the software has become much easier to use, but still it requires a dedicated team and resources that will not be easily generalizable in community practice settings. I don't think it is realistic, especially in this current economic environment, to anticipate routine use of liver volumetry as a method of assessing biliary stent effectiveness in this group of patients."

To study the effects of biliary stenting on liver volume, lead author Dr. Chang Hun Lee of Chonbuk National University Medical School and Hospital in Jeonju, South Korea, and colleagues reviewed data on 60 patients who received self-expandable metal stents, including 31 with hilar bile duct cancer (13 with bilateral stents and 18 with unilateral stents) and 29 with distal bile duct cancer.

The overall median age, 73.1 years, was similar in all three groups.

Over a mean of 11.7 weeks, liver volume increased 17.4% (p<0.001), with rapid growth between the 4th and 8th weeks.

Hilar stents tended to increase liver volume more than distal stents (22.5% vs 11.9%, p=0.091). In hilar bile duct cancer, though, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; p=0.512).

Dr. Muthusamy commented, "This was a novel study and to some degree the findings surprised me in terms of the degree of liver regeneration within the time period observed."

As to whether liver volume can be used as a marker of stent effectiveness, Dr. Muthusamy replied, "That remains to be seen. These findings are certainly food for thought, but this study was retrospective and we need further studies to see if these results can be reproduced.

"This study looked at global volume and global stenting. Future studies need to be prospective and should look at individual segments, which segments were drained and which were not, and individual volumes per lobe," he said.

Dr. Corvera also cautioned about the limitations of this kind of study. "Since this study is retrospective in nature and does not have a control group, the changes in liver volume may have, in fact, been initiated by the disease process and prior to the actual biliary stenting. Thus, the observed changes may merely be more of an effect rather than a cause."

The corresponding author did not respond to requests for comments.

SOURCE: http://bit.ly/1nqVrcy

Gastrointest Endosc 2014.