Early Shift of Lung Perfusion to the Unilateral Lung Predicts the Development of Unilateral Chronic Lung Allograft Dysfunction after Bilateral Living-Donor Lobar Lung Transplantation

Abstract

Purpose In the diagnosis of chronic lung allograft dysfunction (CLAD) after living-donor lobar lung transplantation (LDLLT), lung ventilation scintigraphy using 133 Xe has been shown to be useful. However, the supply of 133 Xe has been discontinued worldwide in 2016 and a new diagnostic tool is required for CLAD after LDLLT. Generally, because CLAD has been shown to develop predominantly on one side after bilateral LDLLT, lung perfusion scintigraphy (LPS) could show a perfusion shift to the unilateral healthy lung ( Figure 1A ). Nevertheless, the usefulness of LPS in the diagnosis of CLAD after LDLLT is unknown. Methods We conducted a single-center retrospective cohort study of 58 recipients who underwent bilateral LDLLT at Okayama University Hospital between October 1998 and June 2016. The unilateral shift values in LPS were calculated, and compared between the CLAD group (N=27) and the non-CLAD group (N=31) from 5 years before the CLAD onset to 5 years after the CLAD onset. Results The median time to the CLAD onset was 2176 days (326-4763 days). The unilateral shift values in LPS of the CLAD group were significantly higher than those of the non-CLAD group during 5 years before the CLAD onset (P Figure 1B ). An ROC analysis of the performance of the unilateral shift value in LPS as a marker of CLAD yielded an AUC of 0.79 (sensitivity=0.54 and specificity=1.00 at a unilateral shift threshold level of 8.6%). The unilateral shift values in LPS were significantly correlated with the results of the forced expiratory volume in 1 second (P = 0.036, r = - 0.322) ( Figure 1C ). Conclusion In the patients with unilateral CLAD after bilateral LDLLT, LPS showed the unilateral perfusion shift to the healthy lung even during 5 years before the CLAD onset. LPS might have a potential to diagnose unilateral CLAD early after bilateral LDLLT.