A cadaveric demonstration of visualization of the urethra using a lighted stent during transanal intersphincteric resection

Urethral injury is one of the crucial intraoperative complications during transanal total mesorectal excision (taTME) for male patients with low rectal cancer. Urethral injury can occur during the anterior dissection around the inferior lobe of the prostate and the membranous urethra. A tool to visualize the urethra around this area would be useful to avoid urethral injury. We report a cadaveric demonstration of visualization of the urethra using a lighted stent during transanal intersphincteric resection. The lighted stent (InfraVision Ureteral Kit, Stryker) was placed through the irrigation channel of a clear three-way urinary catheter. After the anterior dissection, the visibility of the lighted stent was investigated under the three laparoscopic light conditions: (1) normal intensity; (2) low intensity; and (3) turned-off. In the proper dissection plane that led to preservation of the urethra, the lighted stent was hardly visible under the normal-intensity condition, but it was clearly visible under the turned-off condition. In the improper dissection plane that led to urethral injury, the lighted stent was clearly visible under both the normal-intensity and the turned-off conditions. Visualization of the urethra using the lighted stent under the turned-off condition of the laparoscopic light can be useful to avoid inadvertent urethral injury during the anterior dissection of male taTME. Clear visibility of the lighted stent under the normal-intensity condition can indicate that the dissection plane is too close to the urethra.