[Development of new therapeutic method for empyema].

Objectives: We have investigated whether polylactic acid (PLA) sponge and fibroblast-growth-factor (FGF) released slowly from gelatin beads can induce fibrotic tissue in postpneumonectomy dead space.

Methods: Left pneumonectomy was performed in white Japanese rabbits. In the control group (N = 5), left chest was closed without any treatment. In the PLA sponge group (N = 5), PLA sponge and FGF (100 micrograms) released from gelatin beads were introduced into the left chest cavity.

Results: In the control group, herniation of the heart and right lung were observed without fibrotic material in the left chest cavity. In the PLA sponge group, dense fibrotic material was observed by chest CT scan 1 month after the operation. Pathological examinations revealed that PLA sponge and FGF did promote the organization of the fibrotic materials.

Conclusions: Fibrotic materials can be induced in the postpneumonectomy dead space by PLA sponge and FGF released slowly from a gelatin sponge. New therapeutic method may be introduced near future by this concept, reduction of dead space with newly developed own fibrotic materials.