Oar. Binns et al., USE OF OVER-SIZED MATURE PULMONARY LOWER LOBE GRAFTS RESULTS IN SUPERIOR PULMONARY-FUNCTION, The Annals of thoracic surgery, 64(2), 1997, pp. 307-312
Background. Mature lobar transplantation will increase the pediatric d
onor organ pool; however, issues regarding size discrepancy between do
nor grafts and recipient lungs remain unresolved. We hypothesized that
an oversized mature pulmonary lobar allograft implanted into an immat
ure recipient would provide adequate longterm pulmonary function versu
s a size-matched mature lobar graft or an immature whole lung. Methods
. We investigated our hypothesis in a porcine orthotopic left lung tra
nsplant model in which 19 immature animals made up one control and thr
ee recipient groups. Group I underwent sham left thoracotomy (control,
n = 4). Group II received age-and size-matched immature whole left lu
ng transplant (n = 6). Group III received mature size-matched left upp
er robe transplants (n = 4). Group IV received mature over-sized left
lower lobe transplants (n 5). Twelve weeks after implantation, data we
re collected after the native right lung was excluded. Results. Graft
weight was significantly elevated in group IV as compared with the exp
lanted lung (72.4 +/- 6.8 versus 38.3 +/- 4.5 g; p = 0.003). Pulmonary
artery pressure and pulmonary vascular resistance were significantly
elevated in group III as compared with the over-sized mature lower lob
e transplants (51.8 +/- 2.2 versus 40.4 +/- 2.5 mm tig [p < 0.0001] an
d 1,605.9 +/- 117.5 versus 857.6 +/- 133.6 dynes.s.cm(-5) [p < 0.0005]
, respectively). A trend toward decreased oxygenation was identified i
n group II. Conclusions. Over-sized mature lobar grafts provide improv
ed hemodynamics as compared with size-matched grafts. Mature left lowe
r lobe grafts are superior to size-matched upper lobe grafts in this m
odel, probably as a result of an augmented vascular bed. (C) 1997 by T
he Society of Thoracic Surgeons.