Sealing effect of rapidly curable gelatin-poly (L-glutamic acid) hydrogel glue on lung air leak

Background. Air leak is a problem commonly occurring in lung and thoracic o perations. In this study, a rapidly curable hydrogel glue was prepared as t he seal for lung air leak. Methods. Mixing an aqueous solution of gelatin and poly(L-glutamic acid) wi th a water-soluble carbodiimide produced a hydrogel. The sealing effect on the air leak wound of rat lung was compared with that of conventional fibri n glue. Results. The gelatin-poly(L-glutamic acid) hydrogel glue was solidified as rapidly as the fibrin glue, and was significantly more effective in sealing the lung air leak than the fibrin glue. Approximately 80% of the lungs tre ated with the hydrogel glue exhibited no air leak at the lung pressure of 5 0 cm H2O. Urea addition could prevent spontaneous gelatination of the mixed solution at room temperature and did not affect the hydrogel sealing effec t. The bonding strength of the hydrogel glue both with and without urea to the lung tissue was significantly higher than that of the fibrin glue. Conclusions. We concluded that this strong lung adhesion of the gelatin-pol y(L-glutamic acid) hydrogel glue resulted in its superior sealing effect. ( Ann Thorac Surg 1999;67:922-6) (C) 1999 by The Society of Thoracic Surgeons .