Persistence of collateral circulation after correction of XXXX .

@entity235 @entity9931 @entity1498
The persistence of collateral circulation was evaluated one year after the correction of experimental @entity1498 ( @entity9931 ) by assessing renal perfusion with the Xenon 133-washout method and measuring distal aortic blood pressure during cross-clamping of the thoracic aorta. @entity9931 was created in 7 puppies at 2 months of age and was corrected after a follow-up with a venous patch when the @entity235 were 9 months old. Two of the @entity235 were lost during the corrective operation due to anaesthetic complications. Four sham-operated @entity235 served as controls. One year after correction of @entity9931 , four of the @entity235 had a pressure gradient of less than 5 mmHg at the site of @entity9931 and one a pressure gradient of 15 mmHg. In renal perfusion measurements a mean decrease of 49% and 96% was found in the study and control groups, respectively. Blood pressures in the distal aorta decreased 47% and 83%, respectively. Two @entity235 in the study group had a distal blood pressure under 50 mmHg and their renal perfusion decreased markedly. Collateral circulation decreased with time after a good anatomic correction of @entity9931 , so that one year after correction of experimental @entity9931 about one half of the initial collateral capacity remained. This suggests that in most reoperations performed at least one year after the primary corrections, temporal shunting or a left side bypass is necessary to ensure sufficient circulation in the distal organs.
