Robot-assisted transvaginal peritoneoscopy using confocal endomicroscopy: a feasibility study in a porcine model

Optical biopsy methods such as probe-based confocal laser endomicroscopy (pCLE) provide useful intraoperative real-time information, especially during minimally invasive surgery with flexible endoscopic or robotic platforms. By translating the probe at constant pressure across the target tissue, undistorted "mosaics" can be produced. However, this poses ergonomic challenges with a conventional flexible endoscope.

A 100 μm confocal depth pCLE probe was integrated into a previously described seven degrees-of-freedom articulated endoscopic robot. After estimating the average workspace created by a female pneumoperitoneum, the accessibility of the peritoneal cavity by the device for robot-assisted pCLE peritoneoscopy was calculated. To demonstrate its in vivo feasibility, the robot was inserted transvaginally in a pig, under laparoscopic vision. Optical biopsy was performed of several targets within the peritoneal cavity.

The workspace analysis calculated that 88 % of the surface of an estimated average female pneumoperitoneum could be contacted by the probe using the robot transvaginally. In vivo, the robot was manoeuvred to provide views of all abdominal and pelvic organs. At each target there was robotic acquisition of still pCLE images, and slowly translating images for the construction of increased field-of-view mosaics up to 2 mm in length. Optical biopsies took 1-2 min per target, and at 3.5 μm lateral resolution, the mosaic images showed characteristic features of anterior abdominal wall, liver, and spleen.

In the porcine model, the robotically actuated method of performing peritoneoscopy and pCLE mosaicked optical biopsy is safe and provides a consistent means of acquiring near-histological grade images of submesothelial tissue. Clinical translation is likely to provide sufficient accessibility of the peritoneal cavity.