Changes in the fluid compartments and dry weights of reimplanted dog lungs.

We studied changes in fluid compartments and dry weights of reimplanted lungs of dogs during the first 6 wk after operation. Excision and reimplantation caused a large increase in lung weight. The increase in weight was maximal 3 days after operation, was proportionately greater in the upper middle lobe than in the lower lobe, and was principally due to increased extravascular water. Dry weight and noncirculating red cells (measured by subtracting 51Cr-labeled red cell mass from total red cell mass as measured by hemoglobin extraction) also increased within 3 days after operation. Lung weight and extravascular water decreased progressively after 3 days and were normal in 6 wk. Chromated blood mass remaining within excised, passively drained lobes did not change at any stage postoperatively. Three days after operation, frozen lung sections showed minimal alveolar fluid but large amounts of peribronchial and perivascular edema which was occasionally blood tinged; submucosal edema was present in a few bronchi. Using intraalveolar Evans blue dye, we confirmed that several bronchial lymphatics close within 6 h and refenerate during the first postoperative week. Many of observed functional changes in freshly reimplanted lungs are temporally related to changes in extravascular water.