A novel vaginal manipulator for identifying vaginal canal separation line by visible and near-infrared transillumination light: PHARUS Pipe.

Introduction: In total laparoscopic hysterectomy, a uterine manipulator with transillumination functionality is often employed as an instrument to visualize the vaginal canal demarcation line. However, the utilization of this device necessitates an external white light source and a fiber optic cable. In this study, we developed a prototype vaginal manipulator (PHARUS Pipe) with a simpler configuration to visualize the vaginal canal separation line.

Methods: The PHARUS Pipe is constructed from a pipe, an annular array of chip-type light-emitting diodes (LEDs) with a wavelength of warm-white and near-infrared light, and a handle. The pipe, with an outer diameter of 30 mm at the tip and a wall thickness of 3 mm, was molded using a light-guiding resin. The annular LED array was positioned on the end face of the handle side of the pipe, and a battery was integrated into the handle. The pipe was designed with an external surface to provide optimal light emission at the tip in a radial direction, i.e., away from the center of the pipe. The visibility of the transillumination passing through a 3-4 mm thick vaginal wall of porcine uterovaginal specimens was evaluated using a near-infrared compatible laparoscopic imaging system.

Results: The position of the tip of the PHARUS Pipe was clearly delineated through the vaginal wall by warm-white and near-infrared transillumination light. Compared with warm-white light, near-infrared light required less current for successful visualization.

Conclusions: The present results suggest the possibility of identifying the human vaginal canal separation line using the PHARUS Pipe.