Radiological Analysis of Unused Donor Lungs: A Tool to Improve Donor Acceptance for Transplantation?

Abstract

Despite donor organ shortage, a large proportion of possible donor lungs are declined for transplantation. Criteria for accepting/declining lungs remain controversial because of the lack of adequate tools to aid in decision-making. We collected, air-inflated, and froze a large series of declined/unused donor lungs and subjected these lung specimens to CT examination. Affected target regions were scanned by using micro-CT. Lungs from 28 donors were collected. Two lungs were unused, six were declined for non-allograft-related reasons (collectively denominated nonallograft declines, n = 8), and 20 were declined because of allograft-related reasons. CT scanning demonstrated normal lung parenchyma in only four of eight nonallograft declines, while relatively normal parenchyma was found in 12 of 20 allograft-related declines. CT and micro-CT examinations confirmed the reason for decline in most lungs and revealed unexpected (unknown from clinical files or physical inspection) CT abnormalities in other lungs. CT-based measurements showed a higher mass and density in the lungs with CT alterations compared with lungs without CT abnormalities. CT could aid in the decision-making to accept or decline donor lungs which could lead to an increase in the quantity and quality of lung allografts.

Histopathologic and radiologic assessment of nontransplanted donor lungs

“…We previously stated that CT imaging might be a useful tool to assess donor organ quality, and Gauthier and colleagues illustrated the potential role of in vivo CT imaging to assess structural lung diseases . The current study supports these findings and highlights the potential of CT imaging as an important adjunct in the assessment of emphysema.…”

“…Unexpected histologic findings were further reported by Solé‐Violán and colleagues who found histologic evidence of bronchopneumonia in 7/9 (78%) donors, none of whom were clinically suspected of pulmonary infection . In contrast, Ware et al found no or only mild histologic abnormalities in 18/29 (62%) declined donor lungs and our group recently reported absence of radiological abnormalities in 60% of allograft‐related declined lungs …”

“…All collected lungs were procured as previously described . Briefly, this included inflation, cold anterograde flush in the donor with subsequent retrograde flush with Perfadex° preservation solution (XVIVO, Göteborg, Sweden), thorough inspection and subsequent definite decline by the procuring surgeon; followed by transportation to our hospital in a semi‐inflated state on ice.…”

“…In a retrospective study, our group previously identified that 20% of declined lungs could potentially be transplantable after EVLP; and the EXPAND trial recently reported excellent clinical outcomes after EVLP of initially questionable lungs . However, only few studies have systematically assessed the actual abnormalities in lungs that were considered to be of insufficient quality for transplantation . In 2002, Ware et al performed a histologic assessment of 29 declined donor lungs and in 62% none or only mild histologic abnormalities were found .…”

“…In addition, no correlation was found between chest X‐ray findings, gas exchange, duration of brain death, and the observed histologic abnormalities. We previously reported a computed tomography (CT) analysis of 28 nontransplanted donor lungs, which revealed no radiologic abnormalities in 60% of allograft‐related declined donor lungs, despite clinical suspicion of severe abnormalities . Therefore, there is a high need for adequate tools to further assist in the assessment of donor lung quality.…”