Size matching in lung transplantation using predicted total lung capacity

Height is used in allocation of donor lungs as an indirect estimate of thoracic size. Total lung capacity (TLC), determined by both height and sex, could be a more accurate functional estimation of thoracic size. Size-matching criteria based on height versus predicted TLC was retrospectively evaluated, and, furthermore, whether a TLC mismatch was related to clinical and functional complications.

The ratio of donor and recipient height, as well as the ratio of predicted TLC in donors and recipients, were calculated in 80 patients after bilateral lung transplantation. Complications evaluated included persistent atelectasis, persistent pneumothorax and increased number of days in intensive care, occurrence of bronchiolitis obliterans syndrome and limitation of exercise capacity.

Median height donor/recipient ratio was 1.01 (0.93-1.12). Median predicted TLC donor/recipient ratio was 1.01 (with a clearly broader range 0.72-1.41). Neither sex mismatch nor TLC mismatch were related to clinical or functional complications.

Allocation of donor lungs based upon height alone leads to a substantial mismatch in total lung capacity caused by sex mismatch. The absence of complications suggests that a greater height donor/recipient discrepancy can be accepted for allocation than previously assumed.