Should weight be a criterion for lung transplant selection?

Abstract

“...a significant number of patients die while waiting for a lung transplant because of a lack of available organs.” Denis Hadjiliadis, MD, MHS, FRCP(C), FCCP Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, PA, USA and Director, Adult Cystic Fibrosis Program, Associate Medical Director, Lung Transplantation Program, 835W Gates Building, Hospital of the University of Pennsylvania, 3600, Spruce Street, Philadelphia, PA 19104, USA Tel.: +1 215 615 3871 Fax: +1 215 662 3226 denis.hadjiliadis@ uphs.upenn.edu hadjiliadisdenis@ hotmail.com Lung transplantation is considered an acceptable treatment option for end-stage lung disease. The number of transplants performed has continued to increase over the years, reaching 2708 procedures worldwide [1] and 1465 in the USA during 2007 [2]. However, lung transplant outcomes remain inferior to other solid organ transplants with 1-year survival rates of 79% and 5-year survival rates of 52% [1]. In addition, a significant number of patients die while waiting for a lung transplant owing to a lack of available organs [2]. The number of waiting list deaths in the USA improved initially with the new lung allocation score and the donor increase initiative, but has now reached a plateau [2]. Therefore, it remains very important to select patients that have the best chance of survival after lung transplantation, to appropriately allocate this precious resource. According to the most recent guidelines by the International Society for Heart and Lung Transplantation, obesity is a relative contraindication to lung transplantation [3]. Obesity prevalence in the USA has dramatically increased over the last 15 years [101]. Using a definition of BMI above 30 kg/m, only one state in 2008 had a prevalence of obesity less than 20%, while six states had a prevalence of more than 30%. By contrast, in 1994 all 50 states had an obesity prevalence of less than 20% according to data from the CDC [101]. As a result of this rise in obesity, there is a significant increase in the number of obese patients requiring the provision of multiple healthcare services and clinicians frequently face questions on the appropriate management of these patients. These questions and dilemmas are likely to intensify over the next 5–10 years. Some patients with end-stage lung disease are at particular risk of obesity owing to steroid use (e.g., patients with idiopathic pulmonary fibrosis [IPF]). Most recent reports suggest that the effect of obesity is small on survival outcomes. In cardiac surgery, obesity leads to a small but significant increase in mortality [4] and wound infections [5]. In other solid organ transplants, there are conflicting data on the effect of obesity on posttransplant outcomes; most suggest that these patients have worse outcomes [6–8], and almost all of the studies have suggested increased post-transplant complications. In addition, all the aforementioned have mainly considered patients with extreme obesity (BMI >35, or even 40 kg/m).