Airway growth after pediatric lung transplantation

Background: Lung transplantation (LT) has been successfully offered to pedi atric patients. Very little is known about the growth of the transplanted l ung, especially in the infant population. Computerized tomography (CT) scan ning is a simple method for studying pediatric patients who have undergone LT. We evaluated the use of CT scans to assess airway growth after pediatri c LT, compare airway diameter indexed to somatic growth between LT patients and normals, and compare the growth of pre-anastomotic and post-anastomoti c airways indexed to somatic growth in pediatric LT patients. Methods: We reviewed CT scans on all pediatric patients who underwent prima ry LT before their fifteenth birthday between January 1995 and September 19 98. Uniform measurements of diameter were made in pre-anastomotic (trachea, and proximal right and left bronchi) and post-anastomotic (distal right an d left bronchi) sites. These measurements were then correlated with height and compared to previously published normal values. Results: Of the 16 patients who underwent LT during the study period, 11 ha d at least 2 sequential CT scans (LT age 3 months to 14 years, median 2 yea rs). Thirty-one CT scans were reviewed. Inter-observer variability was with in 1 standard deviation (2 mm) in 93% of the measurements and inter-observe r reliability was 0.91 by analysis of variance. Tracheal transverse diamete r plotted against body height (slope 0.0072, correlation coefficient 0.88) was virtually identical to previously published norms. A similar relationsh ip between airway diameter and height was observed in pre-anastomotic and p ost-anastomotic segments. Conclusion: CT scanning is a reliable method for assessing airway growth in pediatric LT recipients. Tracheal growth in pediatric LT recipients is sim ilar to that of normal children. Post-anastomotic large airways grow simila rly to native, pre-anastomotic airways.