A novel simulation for transanal endoscopic operation training

Background

Transanal endoscopic microsurgery (TEM) and transanal endoscopic operation (TEO) have been widely adopted since first being described by Buess et al in 1985. ¹ A specially designed rectoscope is used with laparoscopic imaging and angulated instrumentation to allow precise dissection of rectal lesions under a magnified view. ² We describe a novel ex vivo simulator for TEO/TEM training.

Technique

A porcine rectal specimen was used to simulate the human rectum. A standardised liquid polyp mix is injected into the submucosal layer of the bowel. This solidifies at room temperature, allowing it to remain in situ, providing a realistic rectal lesion when visualised through the transanal endoscopic equipment (Fig 1). The stages of polyp removal can be practised including circumferential excision margin marking, polyp excision and suturing of the rectal defect. This simulation has been trialled by delegates on a laboratory-based TEO course (Fig 2).

Figure 1.

Endoscopic view of simulated transanal resection of superficial rectal lesion: overview (A), circumferential excision margin marking (B), polyp excision (C) and suturing of the rectal defect (D)

Figure 2.

External view of transanal endoscopic operation setup and simulator in use

Discussion

To our knowledge, this is the first TEO simulator to incorporate realistic rectal lesions into the simulation. This is a simple, cost effective way of improving the visual and mechanical realism of the training technique. This has received excellent preliminary course feedback from faculty and delegates. Future work will be directed towards developing this pilot model and providing evidence for its validity.