Lung transplant after cardiothoracic surgery

Lung transplantation following previous cardiothoracic surgical procedures is a technically complex operation with concomitant medical comorbidities contributing to difficulty in managing postoperative patients. We commend Schumer et al. [1] on their study of the UNOS database regarding this patient population. We are however concerned about the conclusion and how it will affect a growing number of potential transplant patients. Within the data provided and analysed, there would appear to be lower survival in patients having undergone previous cardiac surgery (PCS). Not provided is information about the predominance of coronary artery bypass grafting (CABG) operations contributing to this finding and the technical details of previous CABG, which could be expected to affect operative approach. Thirty-day mortality due to graft failure was significantly more common in the PCS group and cardiovascular death more common long-term. While cardiovascular death is not unexpected after PCS, specifically CABG, it highlights the importance of guideline-directed management of coronary artery disease in transplant patients. The increased early mortality due to graft failure suggests issues with donor selection, intraoperative management and early postoperative management, rather than direct incompatibility of PCS with lung transplant.

This study is a national-level database study providing a larger dataset, but less granularity. Multiple single-centre studies regarding this patient population have found similar outcomes in PCS and PTS patients. In 2012, Shigemura et al. [2] reported their outcomes at the University of Pittsburgh Medical Center performing transplantation in patients with previous cardiothoracic surgery and found that while there was a higher rate of postoperative complications, long-term survival was similar. In 2016, Omara et al. [3] performed a retrospective review of patients with prior cardiothoracic operations undergoing lung transplantation at Cleveland Clinic finding similar short- and long-term survival. They noted a longer postoperative intensive care unit stay, but otherwise similar outcomes. Finally, in 2020, Kanaparthi et al. [4] studied patients with previous coronary revascularization (percutaneous or surgical) or undergoing combined lung transplant with CABG at Temple University Hospital and found that length of stay, postoperative complications and long-term survival were similar to that of patients without coronary intervention.

As noted in their article, PCS and PTS patients are a relatively small proportion of the lung transplant population. The PTS group is likely to remain stable moving forward, but it can be expected that the number of patients referred for possible lung transplant with PCS and coronary artery disease will increase as the national population ages overall. The determination that short-term and long-term survival in this group is decreased may lead to fewer referrals and lower priority listing. Thus, we need stronger data on the topic prior to making such conclusions. The strengths of a large database study must be balanced with its weaknesses, especially when multiple single-centre large institutional studies contradict the findings. The surgical technical difficulties must be separated from donor–recipient matching and post-transplant management outcomes, all of which may be improved with better understanding without discarding a small, but growing, population of potential transplant recipients.

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