Usefulness of an ICG fluorescence catheter system in TaTME for avoiding intraoperative urethral injury

Background. Sometimes intraoperative urethral injury occurs in Transanal total mesorectal excision (TaTME). The aim of this study is to investigate the usefulness of indocyanine green (ICG) fluorescent catheter system for avoiding intraoperative urethral injury in TaTME in experimental model. Methods. A urethral catheter was filled with the mixture of albumin and ICG and raw hams were applied in layers as the surrogate model of rectourethral muscle. The detectability of ICG fluorescence in this catheter was investigated by using laparoscope-type fluorescence camera system. Results. Fluorescence was detected when ICG was mixed with albumin or peripheral blood. ICG fluorescence could be detected within 4 mm depth of layered raw hams as the surrogate model. Quantitative analysis of the picture detected that ICG fluorescence plateaued in lower concentration than that of serum. Conclusion. ICG fluorescent catheter system may be useful for avoiding intraoperative urethral injury in TaTME.