The role of computed tomography lung volumes in size-matching lung transplants and optimising recipient outcomes

Purpose: The current recommendation for size matching organs in lung transplantation is the use of ERS’s pTLC formula. The reliability of pTLC is limited in various disease groups, ethnicities, gender and body habitus. Poor size-matching is associated with increased morbidity and mortality. We explore the utility of CT total lung capacity (CT TLC) compared to pTLC for size matching lung transplantation. Method: We performed a systematic review examining the use of CT TLC for size matching lung transplants. Findings: Consistently CT TLC was more closely associated with measured TLC, while pTLC over-estimates volume. Poor size-matching by CT TLC was associated with worse outcomes including longer mechanical ventilation, ICU admission, higher rates of delayed chest closure and PGD. Accurate CT size-matching predicted lower mortality, shorter hospital stay, and lower rates of delayed chest closure, compared to pTLC. Discrepancy between ventilatory mechanics titrated to the recipient, and donor organ requirements is believed to contribute to early graft failure. Objective measures of organ volume may reduce ventilatory barotrauma. CT size-matching provides an avenue to explore lobar transplantation when oversize organs are presented, where otherwise viable tissue would be discarded. CT size-matching may change organ allocation and waitlist mortality. Conclusion: CT TLC is a more accurate means of size matching compared to pTLC. Accurate size matching improves recipient outcomes in both the ICU and long-term setting. Prospective studies are needed to consolidate these findings.