General Surgery News
ISSUE: OCTOBER 2012 | VOLUME: 39:10
Obesity Faulted; Study Shows Transplant Helps Nonalcoholic Steatohepatitis Patients
By Christina Frangou
AT A GLANCE
Population-based studies suggest about 12% of Americans may have fat and inflammation present in the liver.
The epidemic of hepatitis C, which currently accounts for about half of liver transplants in the United States, appears to have peaked and the numbers are expected to slide downward.
Analysis showed that NASH patients required more resources during their surgery and postoperatively, but that long-term survival of NASH patients matches those of other transplant patients.
Researchers identified two predictors of lower survival in NASH patients: obesity and pretransplant hemodialysis
America’s stretched donor pool and limited resources for transplant will come under further stress in the next decade as nonalcoholic steatohepatitis (NASH) supplants hepatitis C as the primary indication for liver transplant, experts say.
According to a study presented at the American Surgical Association’s annual meeting, NASH is now the fastest-growing indicator for liver transplant at the University of California, Los Angeles (UCLA), which has one of the country’s largest transplant programs.
In 2002, NASH was the primary indication for liver transplant in about 3% of all liver transplants at UCLA. By 2011, it accounted for 19% of all liver transplants and was the second most common indication for liver transplant at the center, representing a fivefold increase over nine years.
“NASH will soon become the leading indication for liver transplantation in the United States,” said Vatche Agopian, MD, a transplant surgeon at the David Geffen School of Medicine at UCLA.
The situation in Los Angeles is similar to that at transplant centers across the country, said John P. Roberts, MD, professor of surgery and chief of transplantation at the University of California, San Francisco.
NASH is rising dramatically in the United States, yet another consequence of the sky-high obesity rate. Population-based studies suggest about 12% of Americans may have fat and inflammation present in the liver. At the same time, the epidemic of hepatitis C, which currently accounts for about half of liver transplants in the United States, appears to have peaked and the numbers are expected to slide downward.
Even at its peak, hepatitis C affected about 1% of the U.S. population. The growing prevalence of NASH suggests that a much larger proportion of the population could one day be candidates for liver transplant, said Dr. Roberts.
“It’s changing very fast. My sense is that you are going to see a big switch in indication for liver transplant from hepatitis C to NASH within the next decades,” said Dr. Roberts. “This is where the future is going and it has the potential to overwhelm the system. We’re already short of organs now.”
A study presented at the American Association for the Study of Liver Diseases meeting this fall showed that NASH accounts for an increasing proportion of liver transplants nationally and liver transplant recipients with NASH have poorer survival compared with non-NASH recipients without hepatitis C (Brandman D et al. Temporal trends in liver transplantation [LT] for nonalcoholic steatohepatitis [NASH]; abstract).
The UCLA study is the largest single- institution experience of liver transplant for NASH. Unlike previous research, it demonstrates that NASH patients can have outcomes that are comparable to other patients undergoing liver transplants. Even so, NASH patients place increased demand on hospital resources, the study showed.
Between 1997 and 2011, 144 patients underwent liver transplant for NASH, representing 12% of all liver transplants at UCLA during that time. Before 2002, only eight patients in total underwent liver transplantation for NASH. Since then, the number has leaped upward annually.
Patients with NASH had more pretransplant comorbidities and higher pretransplant acuity than patients who underwent liver transplants for other causes. Two-thirds of NASH patients had a body mass index (BMI) of 30 kg/m2 or greater and/or diabetes; 50% of patients had hypertension and 30% had metabolic syndrome—all significantly higher than in other transplant patients. NASH patients had an average Model for End-Stage Liver Disease score of 33, 45% were on hemodialysis and 17% were receiving vasopressors.
Analysis showed that patients with NASH required more resources during their surgery and postoperatively. They had significantly longer operative times, reaching a median of 6.9 hours compared with 5.3 hours for other patients (P<0.001); they had greater operative blood loss (18 vs. 14 units of packed red blood cells; P=0.004) and a longer total hospital length of stay (35 vs 29 days; P=0.046).
But long-term, the survival of patients with NASH matches those of other transplant patients. One- and three-year graft survival reached 80% and 70%, respectively, and one- and three-year patient survival was 84% and 75%, respectively. The survival rates were similar to those for all other patients undergoing liver transplant except for patients with hepatitis C. Patients with hepatitis C who received liver transplants had much poorer outcomes: a 62% survival and 57% graft survival after three years.
Two factors appear to be important predictors of survival in patients with NASH: namely, patients who had a BMI greater than 35 kg/m2 and patients requiring pretransplant hemodialysis had worse outcomes after transplant. The authors said these factors might help guide the selection of patients who may benefit most from liver transplant.