Failure of the canine principal ascending epicardial lymphatic to regenerate after transection.

We transected the principal ascending anterior epicardial cardiac lymphatic in 10 dogs, and after varying time intervals reoperated to look for lymphatic regeneration using dye injection. Photographs and sketches were made to record the findings, and in six dogs serial histologic sections were also examined. In none of the 10 dogs was regeneration of the transected principal cardiac lymphatic detected although small lymphatic collaterals from the distal side of the lymphatic developed in 2 dogs. Further studies are merited to assess the role of lymphatic insufficiency in the development of coronary vasculopathy and chronic rejection after cardiac transplantation and other heart operations (e.g., coronary artery bypass) that may injure lymphatic drainage capacity.