By John Gever, Deputy Managing Editor, MedPage Today
Published: April 28, 2013
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco
AMSTERDAM -- Elimination of spontaneous liver shunts, or reducing the size of surgically placed shunts, is an effective treatment for hepatic encephalopathy in cirrhotic patients, researchers said here.
A retrospective review of 37 European patients undergoing embolization of spontaneous liver shunts, all of whom had encephalopathy prior to the procedure, found that 59% were free of the condition during the first 100 days of follow-up, said Wim Laleman, MD, of University Hospitals Leuven, Belgium.
A few patients had recurrent encephalopathy later on, but the overall clinical success rate was 49%, Laleman told attendees at the European Association for the Study of the Liver's (EASL) annual meeting.
In a separate presentation at EASL, a colleague of Laleman's in Leuven, Frederik Nevens, MD, reported that patients with hepatic encephalopathy after undergoing transjugular intrahepatic portosystemic shunt (TIPS) for preventing variceal bleeding benefited from a shunt reduction procedure.
Among 55 patients with either persistent encephalopathy or a syndrome known as post-TIPS liver failure, a percutaneous procedure to implant a new, smaller stent to reduce the shunt area led to marked clinical improvements, Nevens said.
Hepatic encephalopathy was reduced or eliminated in 25 of 34 patients for whom that was the most prominent post-TIPS problem. In 21 patients also afflicted with liver failure following TIPS, the condition lifted in nine after shunt reduction.
Both researchers emphasized that the results needed to be replicated in larger samples before these procedures could become standards 0f care.
Hepatic encephalopathy is a frequent complication of liver cirrhosis because the organ loses its ability to remove brain-poisoning toxins from the circulation. The problem can be exacerbated when blood flow to or within the liver is compromised by vascular shunts.
Such shunts may occur spontaneously with liver disease, or they may be placed deliberately in an effort to control variceal bleeding.
Shunt Reduction after TIPS
Nevens said that, in the vast majority of cases, TIPS is helpful to liver cirrhosis patients. The 55 patients undergoing the shunt reduction procedure were the treatment failures in a group of 407 TIPS patients.
The shunt reduction was carried out with what Nevens called the "parallel technique," in which a balloon-expandable stent is placed within the existing shunt. He said a femoral approach has been preferred but that a jugular approach was used in some cases. The target reduction in surface area was 36%.
Although responses to the reduction procedure were generally encouraging, particularly in the patients without liver failure in addition to encephalopathy, it was not a panacea. Nevens noted that nine of the 34 encephalopathy-only patients developed recurrent ascites or variceal bleeding.
Also, of the 21 patients with post-TIPS liver failure, which Nevens characterized as a form of acute-on-chronic liver failure, only 11 survived through follow-up lasting as long as 5 years, including four who subsequently underwent liver transplantation.
Nevens and colleagues examined several potential risk factors for early mortality in the post-TIPS liver failure group. The most important, and potentially modifiable, was the interval between the original TIPS procedure and the reduction. It averaged 20 days in the fatal cases compared with 10 days in survivors.
"We may not have been aggressive enough" in correcting TIPS in the patients who died," Nevens said. Survivors also tended to be younger and have lower MELD (Model for End-Stage Liver Disease) scores, but not to a great degree, he said.
Embolizing Spontaneous Shunts
The other shunt-related complication in cirrhosis involves hepatic vascular defects that arise spontaneously. Laleman noted that attempting to correct them can carry their own risks, such as the potential for thrombosis and aggravated portal hypertension.
Nevertheless, a number of centers in Europe have begun doing such procedures in selected patients. Laleman, Nevents, and their colleagues surveyed six hepatology centers in the U.K., Spain, and Belgium to ask about their experience.
Responses involved a total of 38 patients for whom the procedure was planned, although it was not carried out successfully in one patient. Patients had been treated as long ago as 1998; mean follow-up was about 23 months.
Techniques included transhepatic or femoral vein access, with coils, matrix materials, or "amplatzer" plugs used to embolize the shunts. About half of the shunts were spleno-renal; others were of the mesentericocaval, periumbilical, and mesentericorenal varieties.
Not only was hepatic encephalopathy successfully eliminated in most patients, at least in the short term, but rates of hospitalization due to the condition were reduced by about three-quarters, both within 100 days of embolization and throughout follow-up.
The procedure also restored functional ability in most patients. Whereas 25% of patients were fully autonomous prior to embolization, 65% were described as autonomous afterward.
Laleman noted that eight patients had complications from the procedure. In seven cases these were mild and easily managed, involving such things as hematoma and skin infections. The one major complication was severe bleeding and shock related to transhepatic access, but Laleman said the patient recovered with no long-term adverse effects.
As with TIPS reduction, the embolization did not solve all the patients' problems. Liver function, as quantified by MELD scores, continued to deteriorate, and portal hypertension persisted in patients who had it prior to surgery.
In a multivariate analysis of risk factors for encephalopathy recurrence, the most important predictive factor was MELD score prior to embolization, Laleman said.
He said a MELD score of 11 or less appeared to be a good cutoff for predicting success, with a sensitivity of 66% and specificity of 78%. The lower MELD score, he said, could be taken as an indicator of "sufficient functional liver reserve."
Both studies had no commercial funding. All authors declared they had no relevant financial interests.
Primary source: European Association for the Study of the Liver
Source reference:
Laleman W, et al. "Embolization of large spontaneous portosystemic shunts for refractory hepatic encephalopathy: A European multi-center survey on safety & efficacy" EASL 2013; Abstract 77.
Additional source: European Association for the Study of the Liver
Source reference:
De Keyzer B, et al. "The outcome of shunt reduction after TIPS by the Parallel Technique: A prospective study" EASL 2013; Abstract 79.
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