Alteration of epicardial lymphatics in lymphostatic canine hearts.

This study was conducted in an attempt to establish a method for evaluation of cardiac lymphostasis in autopsy cases and animal experiments. Ten mongrel dogs were operated on to induce cardiac lymphostasis in terms of ligation of coronary lymphatics. From the following day to 6 months after surgery, epicardial lymphatics were visualized to measure the volumes and densities of the lymphatics. The mean volume, measured after 1 week (0.27 +/- 0.09), 2 weeks (0.32 +/- 0.04), and 6 months (0.23 +/- 0.05) continued to be higher than that on the first day (0.16 +/- 0.04) (P less than 0.05). The density, measured after 1 week (2.6 +/- 0.3) and 2 weeks (3.7 +/- 0.7), also showed higher values, than that on the 1st day (1.7 +/- 0.7) (P less than 0.01). However, 6 months later, the measured value (1.9 +/- 0.03) showed no statistical difference compared to that of the 1st day. Observation under a binocular microscope revealed impressions of a progressive increase in both number and thickness of the lymphatics as late as 2 weeks after the induction. However, 6 months later, there was marked dilatation and a relative decrease in the number of lymphatics.