The quest for precision in transanal total mesorectal excision

Abstract

Transanal total mesorectal excision (TME) is an emerging minimally invasive approach to rectal cancer, with encouraging preliminary results. However, the new surgical anatomy of the bottom-up approach complicates surgical understanding and increases the risks of inadvertent injuries to crucial anatomical structures, including nerves. Key elements to improve the safety and stimulate interest in such a complex technique might be robotics and image guidance, to enhance the level of precision. In this editorial, some of the technologies that could be used for precision TME are outlined, in light of the experience of our Institute for Image-Guided Surgery.

Abdomino-endoscopic perineal excision of the rectum for benign and malignant pathology: Technique considerations for true transperineal verus transanal total mesorectal excision endoscopic proctectomy

“…Improved MRI selection can also of course help with understanding dissection vectors and include the possibility of real-time, intraoperative feedback via stereotactic augmentation of instrument tip and direction to help with correct planar orientation and ensure completeness of mesorectal excision. [20]…”

Virtual reality simulation for surgery: from video games to transanal total mesorectal excision

“…Once in the operating room, VR images can guide surgical navigation, enhancing the surgeons' view of the operating field by combining the 1 3 visual field with the radiology images. Fluorescence guidance by the augmented eye [9] is a non-invasive method that allows real-time cartography of structures (ureters and nerves), labeled by injected fluorophores, which are excited by near-infrared laser cameras [10]. Another asset of the VR glasses being developed is the ability to provide real-time microscopic images with confocal laser endomicroscopy (CLE) [9], which generates digital "biopsies" at micronlevel resolution.…”

“…Fluorescence guidance by the augmented eye [9] is a non-invasive method that allows real-time cartography of structures (ureters and nerves), labeled by injected fluorophores, which are excited by near-infrared laser cameras [10]. Another asset of the VR glasses being developed is the ability to provide real-time microscopic images with confocal laser endomicroscopy (CLE) [9], which generates digital "biopsies" at micronlevel resolution. This technique could translate into a precise estimation of tumor margins and could end unnecessary sacrificing of the anal sphincters or reinterventions due to positive margins in oncologic resections.…”

“…This technique could translate into a precise estimation of tumor margins and could end unnecessary sacrificing of the anal sphincters or reinterventions due to positive margins in oncologic resections. The augmented hand [9] is a flexible device that overcomes the rigidity of the laparoscopic instruments that could be the solution for the pure natural orifice transluminal endoscopic surgery (NOTES) taTME [11], where the dissection is performed completely transanally. With current rigid instruments, it is difficult to reach the splenic flexure, due to the angle formed by the promontory, while this VR minimally invasive "hand" enables surgical triangulation, overcoming this limitation.…”

“…One of the major drawbacks limiting the proliferation of the enhanced reality devices is the lack of haptic feedback on the VR controllers, a key capability that controllers are required to have. VR with haptic feedback is at least as effective in training as traditional box trainers and makes possible shorter operative times and more efficient movements [9]. Creating effective haptic sensors on the VR systems providing force and tactile feedback to the surgeon from the operative field via the laparoscopic instruments is challenging and still under development and evaluation, but will be essential for efficient training and simulation.…”