COLONIC ENDOSCOPIC SUBMUCOSAL DISSECTION USING MASTER ROBOTIC SYSTEM – A PRECLINICAL STUDY

Aims:

One of the difficulties in performing endoscopic submucosal dissection (ESD) is the lack of retraction during submucosal dissection. The development of master and slave transluminal endoscopic robot (MASTER) aimed to enhance safety and efficacy of ESD through two flexible robotic arms for tissue retraction and dissection. This is a preclinical animal study to evaluate performance of colorectal ESD using latest version of MASTER.

Methods:

The latest version of MASTER consisted of an independently designed flexible platform with build-in imaging system and working channels for passage of robotic arms [Figure 1]. In this animal study, outcome measures included operating time (from starting incision to finishing dissection), completeness of resection, procedure-related complications as well as limitation of arms manipulation in narrow working space.

Results:

A total of 5 colorectal ESD procedures were performed in a 66.7 kg porcine model under general anesthesia. The mean operative time was 73.8 minutes, and size of specimen resected was 1340 mm². There was no perforation while profuse bleeding was encountered during one procedure. Hemostasis was achieved after adequate exposure of bleeding arteriole by retracting the mucosal with robotic arm. The en-bloc resection rate was 100%.

Tab. 1:

Outcomes of Colorectal ESD using MASTER in porcine model

Sigmoid (36 cm from verge)	OT time: 68 mins	Dissection time 46 mins	Specimen size 35 × 35 mm	No complication
Rectum (5 cm from verge)	OT time: 46 mins	Dissection time 26 mins	Specimen size 50 × 45 mm	No complication
Sigmoid (28 cm from verge)	OT time: 30 mins	Dissection time: 18 mins	Specimen size 25 × 25 mm	No complication
Sigmoid (36 cm from verge)	OT time: 158 mins	Dissection time: 100 mins	Specimen size 40 × 50 mm	Intra-procedural bleeding
Sigmoid (24 cm from verge)	OT time: 79 mins	Dissection time: 67 mins	Specimen size 20 × 30 mm	No complication

Conclusions:

This study confirmed the feasibility and safety in performing ESD using MASTER system in porcine colon. This provided an important preclinical experience for the conduction of clinical trial.