Segmental flow-resistance relationship in pulmonary lobar transplantation: possibility for donor lobe evaluation in pediatric lung transplantation

: Pulmonary lobar transplantation is an option for pediatric lung transplantation, and it has the potential of extended applications. We compared the relationship between segmental blood flow and segmental vascular resistance of the pulmonary lobe with that of the transplanted single lung. Eight of 14 puppies received a left upper pulmonary lobe from double-weighed adult dogs, and the other six puppies received a left lung from puppies. All recipient dogs were treated with oral cyclosporine (15 mg/kg/day) and intramuscular prednisolone (1.0 mg/kg/day), after the operation. Pulmonary arterial and left atrial pressures and segmental flow of the lungs were measured at rest and while the inferior vena cava or right pulmonary artery was clamped, before and 1 hour and 2 weeks after lung transplantation. Vascular resistance of the lung segment was calculated at each hemodynamic state. Segmental resistance of the lung at rest significantly increased from pretransplantation to 1 hour after transplantation (pulmonary lobe group, 2211 +/- 42 to 2555 +/- 61 dyne.sec.cm-5; single lung group, 2126 +/- 56 to 2557 +/- 72 dyne.sec.cm-5) and recovered 2 weeks after transplantation in both groups. However, by means of partial clamp of the right pulmonary artery, segmental resistances of 1 hour after transplantation pulmonary lobe (2248 +/- 37 dyne.sec.cm-5), and single lung (2206 +/- 34 dyne.sec.cm-5) at the same segmental flow of the pretransplantation state (310 to 320 ml/min) were equivalent to those of the pretransplantation lungs. There was no significant difference in the segmental resistance at any segmental flow between the pulmonary lobe and single lung before and after lung transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)