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Volume: 14 Issue: 6 December 2016

FULL TEXT

ARTICLE
Listing Practices for Morbidly Obese Patients at Liver Transplantation Centers in the United States

Objectives: The effect of morbid obesity on liver transplant outcomes has yielded mixed results. The aim of this study was to determine listing practices for morbidly obese patients at liver transplant centers in the United States.

Materials and Methods: A 19-item survey was created to assess liver transplant evaluation and listing practices for morbidly obese patients. All adult liver transplant medical and surgical directors in the United States were contacted by e-mail, which provided an Internet link to an online survey.

Results: We sent a total of 187 surveys by e-mail, with responses received from 46 physicians (24.7% response rate). A policy on evaluation and listing of obese patients was present at 70.5% of institutions, with most (54.5%) reporting that their body mass index cutoff for transplant was 40 kg/m2, but a range of 35 kg/m2 to unlimited was noted. Most respondents agreed that patients with high body mass index were less likely to be evaluated for transplant. Respondents reported increased complication rates among obese patients, with the most common being poor wound healing and increased infection rates.

Conclusions: Most medical and surgical liver transplant directors have a strong appreciation of the possible morbidity risks associated with performing liver transplants in morbidly obese patients and have policies in effect to minimize these risks.


Key words : Morbid obesity, Operative risk, Body mass index

Introduction

The prevalence of obesity in the United States is currently estimated to affect approximately 35% of the population.1 The most severe classes of obesity are rising sharply, with numbers of individuals with body mass index (BMI) distribution class III obesity (BMI ≥ 40 kg/m2) quadrupling and BMI ≥ 50 kg/m2 quintupling between 1986 and 2000.2 A cross-sectional analysis of an ethnically diverse population in the United States found that the prevalence of nonal­coholic fatty liver disease to be 30% and nonalcoholic steatohepatitis to be 12%, thus closely mirroring the obesity epidemic.3 In light of these statistics, liver disease secondary to nonalcoholic steato­hepatitis has been projected to become the leading indication for liver transplant in the next 10 years.4,5

The use of obesity as a factor in health resource allocation decisions has received increased attention in recent years. Although obesity has been assumed to have negative long-term health consequences, the relation between obesity and inferior outcomes during acute critical illness and major surgery, including liver transplant, remains controversial.6-8 Analyzing the effect of obesity on outcomes of patients undergoing liver transplant has been considered challenging because the conventional measurement of obesity, BMI, may overestimate obesity in patients with anasarca and may not be appropriate for non-European ethnic groups.8,9 Despite this, morbid obesity, as measured by BMI, is used by some transplant centers as a factor in making the decision to add a patient to their liver transplant wait list. The aim of our study was to determine an overall consensus of listing practices for morbidly obese patients at liver transplant centers in the United States.

Materials and Methods

Participants
All medical and surgical liver transplant directors in the United States were invited to participate. A list of all 112 United Network for Organ Sharing-certified liver transplant centers in the United States was obtained. E-mail addresses for directors were found on the institution Web site or by Internet search engine.

Survey instrument and administration
A 19-item survey was created to assess specific program listing practices and observations on the topic of morbidly obese patients referred for liver transplant (see Supplement). Exemption status was obtained from the Thomas Jefferson University Institutional Review Board. Most questions allowed for free-text comment. All directors were contacted via e-mail with a cover letter describing the study and an Internet link to the SurveyMonkey Web site where they could anonymously complete the survey. Five follow-up e-mails were sent after the initial e-mail to encourage participation. Descriptive statistics were used to characterize demographics and question responses.

Results

Characteristics of responders
We contacted a total of 187 participants, with responses received from 46 physicians (24.7% response rate). The physicians reported to being in practice for a median of 20 years (minimum of 7 and maximum of 30 years). The physicians consisted of 29 medical directors and 17 surgical directors and included physicians from all of the United Network Organ Sharing regions, although regions 4 and 6 had the fewest respondents (n = 2). 78.2% physicians reported to be at an academic medical center (73.3%) and performing more than 50 liver transplants a year (60.8%) (Table 1 and Figure 1). A median Model for End-Stage Liver Disease score at transplant of 28 (range, 20-38) was reported.

Current listing practices for morbidly obese patients
A policy on evaluation and listing of obese patients was present at 70.5% of responding institutions, with most (54.5%) reporting that their BMI cutoff for transplant was 40 kg/m2, but a range of 35 kg/m2 to unlimited was noted (Figure 2). Most physicians (61.4%) agreed that there has been an increase in the number of obese patients that they have listed for liver transplant in recent years. Despite this, 75% reported that patients with high BMI values were less likely to be offered transplant evaluation. This result differed between groups, with 79% of medical directors reporting that they have not started liver transplant evaluations on patients as a result of elevated BMI compared with only 62.5% of surgical directors. Programs appeared to be actively working with patients on this issue, as 72% reported having a weight loss program in place for obese patients referred for liver transplant.

Liver transplant concerns for morbidly obese patients
Regarding complications in obese patients, 65.9% reported experiencing increases in complication rate, with the most frequent complications being poor wound healing and increased infection rates (Figure 3). A longer hospital stay was expected for obese patients after liver transplant by 77% of the physicians. Despite the reported increased complication rate, only 34.1% of centers reported that they had experienced worse survival rates with obese patients.

Discussion

Since 2004, the number of patients on wait lists for liver transplant with end-stage liver disease secondary to nonalcoholic steatohepatitis has tripled, and this condition is now the second leading reason and fastest rising indication for entering a liver transplant wait list in the United States.10 From 2004 to 2013, new wait list registrants with nonalcoholic steatohepatitis increased by 170% (from 804 to 2174), those with alcoholic liver disease increased by 45% (from 1400 to 2024), and those with hepatitis C virus infection increased by 14% (from 2887 to 3291).10-12 Even so and for reasons that are not fully clear, adults with nonalcoholic steatohepatitis are less likely to survive for 90 days on the wait list and less likely to get a new liver within 90 days compared with other causes of liver disease, including hepatitis C virus and alcohol-induced liver disease.10

Understanding the independent and additive risks of obesity on outcomes after liver transplant represents a pivotal aspect of pretransplant treatment. This is particularly important when we are considering whether allocation decisions based on obesity and other lifestyle diseases are appropriate. Our study found that most medical and surgical liver transplant directors have a strong appreciation of the possible morbidity and mortality risks associated with morbidly obese patients after transplant and have policies in effect to minimize these risks.

We expect that the number of patients with obesity and end-stage liver disease will continue to grow.13 Developing evidence-based and uniform policies will be important to providing high-quality care to patients requiring liver transplants. This is of specific concern due to the need to provide more high-quality and cost-effective transplant care in the present health care climate. Optimal treatment of these patients may be by a multidisciplinary approach. An example of this is the Mayo Clinic experience with combined liver transplant plus sleeve gastrectomy, which has resulted in effective weight loss in patients and has been associated with fewer posttransplant metabolic complications.14

This study has several limitations. Despite a fair overall response rate, the results may have been biased because most respondents were medical directors as opposed to surgical directors. Also, a lack of knowledge about respondents’ specific program characteristics does not allow us to fully examine for response bias. In addition, questions may not have been interpreted consistently by the responders, and responses about outcomes were anecdotal and not factual. Program decisions about how a center determines a specific BMI cutoff were also not known. Some programs could have a cutoff for perceived medical reasons, whereas other, potentially smaller programs may be less willing to take a risk on a morbidly obese patient for fear of influencing their publicly available transplant statistical outcomes.

In conclusion, there is variability in liver transplant listing practices with respect to obese patients with liver failure. Often, due to their obesity and concomitant metabolic factors, this patient group does not get referred for liver transplant evaluation as there is a general perception by many physicians of an increased morbidity and mortality in this patient cohort. With the surging prevalence of obesity-related nonalcoholic steatohepatitis and metabolic syndrome, evidence-based policies should be developed and enforced among all transplant programs. Outcome data regarding the safety and success of bariatric surgical procedures (such as lap bands and gastric bypass) to improve BMI in this patient population would be very helpful in determining whether more morbidly obese patients could become eligible for liver transplant. In addition, more data are urgently needed on examining morbidly obese cirrhotic patient posttransplant outcomes perioperatively, stratified by other comorbidities.


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Volume : 14
Issue : 6
Pages : 646 - 649
DOI : 10.6002/ect.2015.0247


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From the 1Division of Gastroenterology and Hepatology, Department of Medicine; and the 2Division of Transplantation, Department of Surgery, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
Acknowledgements: The authors have no conflicts of interest to declare. Although no grant support was used for this research, departmental funds were used.
Corresponding author: Dina Halegoua-De Marzio, 132 S. 10th St., Main Building, Suite 480, Philadelphia, PA 19107, USA
Phone: +1 215 955 89 00
E-mail: dlh004@jefferson.edu