Airway growth after pediatric lung transplantation

Lung transplantation (LT) has been successfully offered to pediatric patients. Very little is known about the growth of the transplanted lung, especially in the infant population. Computerized tomography (CT) scanning is a simple method for studying pediatric patients who have undergone LT. We evaluated the use of CT scans to assess airway growth after pediatric LT, compare airway diameter indexed to somatic growth between LT patients and normals, and compare the growth of pre-anastomotic and post-anastomotic airways indexed to somatic growth in pediatric LT patients.

We reviewed CT scans on all pediatric patients who underwent primary LT before their fifteenth birthday between January 1995 and September 1998. Uniform measurements of diameter were made in pre-anastomotic (trachea, and proximal right and left bronchi) and post-anastomotic (distal right and left bronchi) sites. These measurements were then correlated with height and compared to previously published normal values.

Of the 16 patients who underwent LT during the study period, 11 had at least 2 sequential CT scans (LT age 3 months to 14 years, median 2 years). Thirty-one CT scans were reviewed. Inter-observer variability was within 1 standard deviation (2 mm) in 93% of the measurements and inter-observer reliability was 0.91 by analysis of variance. Tracheal transverse diameter plotted against body height (slope 0.0072, correlation coefficient 0.88) was virtually identical to previously published norms. A similar relationship between airway diameter and height was observed in pre-anastomotic and post-anastomotic segments.

CT scanning is a reliable method for assessing airway growth in pediatric LT recipients. Tracheal growth in pediatric LT recipients is similar to that of normal children. Post-anastomotic large airways grow similarly to native, pre-anastomotic airways.