Combined lung and liver transplantation (CLLTx) has been shown to be a viable option for patients with end-stage lung disease secondarily compromised with liver disease. Although multiorgan transplantation has gained increasing acceptance, there is still debate regarding the equity of dual organ allocation in a procedure in which the indication is not well defined. Frieschlag et al1 provide a thought-provoking analysis of SRTR data comparing propensity-matched cohorts of lung-liver and liver-alone transplantation. Although they were unable to find a statistically significant difference in survival outcomes, the authors suggest that the procedure may not always warrant transplantation for both organs due to a lack of observed difference. Their recommendation for restraint with CLLTx aligns with the ethical concerns regarding multiorgan transplantation: Donor organs are a scarce resource, and in an era where waitlists continue to grow faster than the number of people being transplanted, there needs to be definitive data to justify this type of organ utilization. However, the lack of data is the crux of the problem. We have limited patient outcomes regarding CLLTx, and so the interpretation of observed trends should be taken with caution. Additionally, more robust data will provide us the necessary information to improve our selection criteria for CLLTx. This includes patients with liver disease precluding them from surviving lung transplant alone.
The opportunity for CLLTx is in patient selection. Identification of suitable candidates is complex because there is insufficient data to compare each group. Detailed patient outcomes have come from single-center reports; and, although the various transplant centers are not uniform in their approach to CLLTx, each experience provides additional information that can help shape our understanding for this complex procedure. Currently, there are single-center published reports that have shown benefit for CLLTx compared with lung transplant alone. These studies have shown a greater risk of waitlist mortality in CLLTx candidates compared with patients awaiting solitary lung or liver transplant2 and equivalent survivability to solitary organ transplantation.3,4 Center-specific descriptive data have shown the demographic landscape of these patients and the etiology for morbidity and mortality.4
Although the SRTR database can provide a larger volume of cases to analyze at once, there are many missing components that can alter one’s interpretation of the data. For instance, the severity of liver disease can be different despite similar MELD scores. Liver dysfunction is better evaluated by biopsy-proven cirrhosis and the presence of portal hypertension precluding.5 This is information not found in the database. Additionally, the etiology of lung and liver disease is not well defined in these data but may influence outcomes in this patient population.
The utility of CLLTx is also based on the knowledge that there is increased risk of mortality in cirrhotic patients undergoing surgery. The mortality risk of nonhepatic surgery in patients with cirrhosis increases to 50%.6 The relative risk of 30- and 90-day mortality increases by 14% with each point increase in a MELD score over 8.7 This would not only become unacceptable from an outcomes standpoint but also to a patient care perspective. Every patient should deserve the opportunity for improved survival over their current disease. This includes those with biopsy proven cirrhosis and end-stage lung disease.
The potential to help future patients must be weighed against the risks of maleficence and futility. Combined lung and liver transplantation is a complex procedure that carries a theoretical societal cost (“2 organs in 1”), but these patients are critically ill and may not survive lung transplant alone. Combined lung and liver transplantation also addresses these perceived inequalities through the “sickest first” principle, as supported by observations in waitlist mortality. The observation that there is no difference in survival between propensity-matched CLLTx and lung transplant alone should not suggest that there is no benefit in CLLTx in these patients. Instead, this observation should be interpreted as a triumph in CLLTx because outcomes are matched and therefore appropriate. We should continue to pursue CLLTx and refine our prognostic abilities to enable effective allocation decisions to justify multiorgan transplantation in this patient population.
1. Freischlag K, Ezekian B, Schroder PM, et al. A propensity matched survival analysis: do simultaneous liver-lung transplant recipients need a liver? Transplantation IN PRESS.
2. Wolf JH, Sulewski ME, Cassuto JR, et al. Simultaneous thoracic and abdominal transplantation: can we justify two organs for one recipient? Am J Transplant. 2013;13:1806–1816.
3. Barshes NR, DiBardino DJ, McKenzie ED, et al. Combined lung and liver transplantation: the United States experience. Transplantation. 2005;80:1161–1167.
4. Yi SG, Burroughs SG, Loebe M, et al. Combined lung and liver transplantation: analysis of a single-center experience. Liver Transpl. 2014;20:46–53.
5. Ripoll C, Groszmann R, Garcia-Tsao G, et al. Hepatic venous pressure gradient predicts clinical decompensation in patients with compensated cirrhosis. Gastroenterology. 2007;133:481–488.
6. Bhangui P, Laurent A, Amathieu R, et al. Assessment of risk for non-hepatic surgery in cirrhotic patients. J Hepatol. 2012;57:874–884.
7. Teh SH, Nagorney DM, Stevens SR, et al. Risk factors for mortality after surgery in patients with cirrhosis. Gastroenterology. 2007;132:1261–1269.