In vivo assessment of changes in air and tissue volumes after
pneumonectomy.
Takeda, S., E. Y. Wu, R. H. Epstein, A. S. Estrera, and C. C. W. Hsia.
Depts. of Internal Medicine, Radiology and Surgery, University of
Texas Southwestern Medical Center, Dallas, Texas 75235-9034
APStracts 3:0539A, 1996.
We examined the progression and topographical distribution of
postpneumonectomy volume changes in immature foxhounds undergoing
right pneumonectomy (R-PNX, n=5) or sham pneumonectomy (SHAM, n=6) at
2 months of age and subsequently raised to maturity. Volumes of lung
air (VA) and tissue (Vt) were estimated by CT scan at 7, 22 and 52
weeks after surgery at a transpulmonary pressure of 20 cmH2O.
Estimates of Vt by CT scan included both septal tissue as well as
non-septal tissue (small and medium sized airways and blood vessels);
these were compared to estimates of septal tissue volume by an
acetylene rebreathing (RB) method. We found significant correlations
between these techniques (VACT=0.83VARB&275, R=0.97,
VtCT=1.62VtRB-30, R=0.81). Extravascular septal Vt returned to normal
7 weeks after R-PNX and remained normal up to maturity. Non-septal Vt
remained significantly below normal. The greatest increase in Vt
occurred in the mid-lung region just cephalad and caudal to the
heart. After an early period of accelerated tissue growth after R
-PNX, the rate of septal tissue growth matched that of somatic growth,
while non-septal tissue growth lagged behind. Compensatory growth of
the remaining left lung was not associated with selective alterations
in thoracic development.
Received 22 August 1996; accepted in final form 13 November 1996.
APS Manuscript Number A816-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996