{'fraction_non_alphanumeric': 0.03331598125976054, 'fraction_numerical': 0.022904737116085372, 'mean_word_length': 5.2200647249190935, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Propensity Matched Survival Analysis: Do Simultaneous Liver-Lung Transplant Recipients Need a Liver?

BACKGROUND
There is debate whether simultaneous lung-liver transplant (LLT) long-term outcomes warrant allocation of 2 organs to a single recipient. We hypothesized that LLT recipients would have improved posttransplant survival compared to matched single-organ lung recipients with an equivalent degree of liver dysfunction.


METHODS
The OPTN/UNOS STAR file was queried for adult candidates for LLT and isolated lung transplantation from 2006-2016. Waitlist mortality and transplant odds were calculated for all candidates. Donor and recipient demographic characteristics were compiled and compared. LLT recipients were matched 1:2 with a nearest neighbor method to single-organ lung recipients. Kaplan-Meier methods with log-rank test compared long-term survival between groups. Univariate regression was used to calculate the association of LLT and mortality within 6-months of transplant. A proportional hazards model was used to calculate risk-adjusted mortality after 6-months posttransplantation.


RESULTS
Thirty-eight LLT patients were matched to 75 single-organ lung recipients. After matching, no differences in baseline demographics or liver function were observed between cohorts. Length of stay was significantly longer in LLT recipients compared to isolated lung recipients (45.89 days vs. 22.44 days, p<0.001). There was no significant difference in survival probability between LLT and isolated lung transplant (1-year 89.5% vs. 86.7%, 5-year 67.0% vs. 64.6, p=0.20).


CONCLUSIONS
After matching for patient characteristics and level of liver dysfunction, survival in simultaneous LLT was comparable to isolated lung transplantation. While this population is unique, the clinical picture prompting liver transplant is not clear. National guidelines to better elucidate patient selection are needed.