Fluorescence diagnosis of endometriosis on the chorioallantoic membrane using 5-aminolaevulinic acid.

The chorioallantoic membrane (CAM) is a useful model for the fluorescence diagnosis of experimentally induced endometriosis. In our experimental setup 75.7% of the histologically examined tissue preparations were viable and only 24.3% showed signs of necrosis on the CAM after various periods of incubation. Best results were obtained when grafting to the CAM was performed between days 7 and 9 and when implants were left on the CAM for 3-5 days (P < 0.05). We were able to demonstrate that 5-aminolaevulinic acid (ALA) is stored selectively in ectopic endometrium. The subsequent fluorescence of the endometrium shows a rapid increase that reaches a peak after 10-14 h which can be clearly differentiated from the weaker fluorescence of grafted normal peritoneum and fimbriae (P < 0.01).