Unilateral Chronic Lung Allograft Dysfunction Assessed by Biphasic Computed Tomographic Volumetry in Bilateral Living-donor Lobar Lung Transplantation

Abstract

BackgroundEarly diagnosis of unilateral chronic lung allograft dysfunction (CLAD) is difficult because the unaffected contralateral lung functions as a reservoir in bilateral living-donor lobar lung transplantation (LDLLT). We previously reported the usefulness of 133Xe ventilation scintigraphy for detection of unilateral change, but the supply of 133Xe has been stopped globally. The present study aimed to examine the usefulness of inspiratory and expiratory computed tomography (I/E CT) volumetry for detection of unilateral change in CLAD patients.MethodsThis was a retrospective single-center, observational study using prospectively collected data. A total of 58 patients who underwent bilateral LDLLT from August 2008 to February 2017 were analyzed. Respiratory function tests, I/E CT were prospectively conducted. ΔLung volume was defined as the value obtained by subtracting expiratory lung volume from inspiratory lung volume.ResultsFourteen (24%) cases were clinically diagnosed with CLAD, of which 10 (71%) were diagnosed as unilateral CLAD. ΔLung volume of bilateral lungs strongly correlated with forced vital capacity (r = 0.92, P < 0.01) and forced expiratory volume in 1 second (r = 0.80, P < 0.01). Regardless the phenotypes (bronchiolitis obliterans syndrome or restrictive allograft syndrome) of CLAD, Δlung volume onset/baseline significantly decreased compared with that in the non-CLAD group. Among the 10 unilateral CLAD patients, 3 with clinically suspected unilateral rejection yet did not show a 20% decline in forced expiratory volume in 1 second. In 2 of these, Δlung volume of unilateral lungs on the rejection side decreased by 20% or more.ConclusionsOur findings suggest that I/E CT volumetry may be useful for assessment and early diagnosis of unilateral CLAD after bilateral LDLLT.

Lung perfusion scintigraphy to detect chronic lung allograft dysfunction after living-donor lobar lung transplantation

“…Until 2016, ventilation scintigraphy with 133 Xe washout imaging was used for the diagnosis of unilateral CLAD after bilateral LDLLT 5 , but the use of 133 Xe was discontinued. As an alternative diagnostic tool, inspiratory and expiratory computed tomography volumetry has been used to detect unilateral CLAD after bilateral LDLLT, but this volumetric method rarely allows the early detection of CLAD 12 . By contrast, our study showed that the perfusion shift in Q-scinti predicts the development of unilateral CLAD from 5 years before the diagnosis of CLAD after bilateral LDLLT.…”

Impact of chronic lung allograft dysfunction, especially restrictive allograft syndrome, on the survival after living-donor lobar lung transplantation compared with cadaveric lung transplantation in adults: a single-center experience

“…For a definitive diagnosis of CLAD, blood examinations, chest X-ray, computed tomography of the chest, inspiratory and expiratory computed tomography volumetry, ventilation-perfusion scanning, and electrocardiography were also performed at the same time as the pulmonary function testing. Among these, computed tomography of the chest, inspiratory and expiratory computed tomography volumetry, and ventilation-perfusion scanning were mainly used to exclude other potential causes of a reduced lung function [4,7,12,13]. The six-minute walk test and echocardiography were performed at the same time during the first five years after LT.…”

Chronic Lung Allograft Dysfunction Post Lung Transplantation: A Review of Computed Tomography Quantitative Methods for Detection and Follow-Up

“…Measurement of inspiratory and expiratory CT lung volumes can be easily performed and CT volumetry has been shown to differentiate RAS patients from BOS patients due to the strong positive correlation between inspiratory lung CT volumes and TLC [ 20 ]. Computed tomography is particularly useful for detecting CLAD affecting a single lung [ 7 , 21 ], because the unaffected contralateral lung compensates for the deficit in lung function on PFTs. A decrease over time in the difference between inspiratory and expiratory lung volumes has been reported for obstructive and restrictive CLAD phenotypes [ 21 ].…”

“…Computed tomography is particularly useful for detecting CLAD affecting a single lung [ 7 , 21 ], because the unaffected contralateral lung compensates for the deficit in lung function on PFTs. A decrease over time in the difference between inspiratory and expiratory lung volumes has been reported for obstructive and restrictive CLAD phenotypes [ 21 ].…”

“…CT: computer tomography, CLAD: chronic lung allograft dysfunction. Airway measurement methods [ 8 , 9 , 12 , 14 ], Vascular measurement methods [ 14 ], Parenchyma based methods [ 10 , 11 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ].…”