CRC ESD with 2nd-gen flexible endoscopic robotic system pioneered in HK

Researchers from the Chinese University of Hong Kong (CUHK) have launched the world’s first clinical trial of robotic endoscopic submucosal dissection (ESD) of early-stage colorectal cancer (CRC) using a second-generation flexible endoscopic robotic system developed jointly with investigators in Singapore.

“The new system, known as EndoMaster EASE, is an endoluminal robotic system consisting of an independently designed flexible endoscopic platform, three working channels for two robotic arms and accessories, and an independent water-jet system,” said Professor Philip Chiu of the CUHK Jockey Club Minimally Invasive Surgical Skills Centre.

“Our previous study showed that the EndoMaster robotic system can be used to perform ESD and effectively treat patients with early gastric neoplasia,” explained Chiu. [Clin Gastroenterol Hepatol 2012;10:1117-1121] “The second-generation EndoMaster EASE system is redesigned and developed for performing ESD in the colorectum, which presents a higher level of technical challenge due to the colorectum’s long and winding shape as well as thin wall. It allows tissue retraction with excellent visualization to enhance the safety of submucosal dissection.”

The clinical trial aims to recruit 46 patients with early-stage CRC – a group with growing demand for ESD due to the increasing number of cases identified through CRC screening programmes.

As of 15 September 2020, six patients with early-stage CRC had undergone robotic ESD in the trial. “Negative resection margin was achieved in all six patients, with no perforation or post-ESD bleeding. The mean operation time was 88 minutes, while mean length of hospital stay was 2 days. The patients were able to resume a normal diet 1 day after the procedure,” reported Chiu. “The first patient underwent colorectal ESD with the EndoMaster EASE system at our centre in May 2020. Another two patients are recruited recently into the trial and are to undergo preoperative assessment shortly.”  

“In Hong Kong, about 60 percent of CRC cases discovered through the government’s CRC screening programme are early-stage cases suitable for ESD. At the Prince of Wales Hospital alone, 150 cases of ESD for early-stage CRC were performed in 2019,” said Professor Simon Ng of the Division of Colorectal Surgery, CUHK.  

“However, ESD is technically very challenging, involving a learning curve of 80–100 cases and an operation time of 2–3 hours. If performed by inexperienced endoscopists, the risk of complications is relatively high, with our previous study reporting a 65.2 percent perforation rate and a 56.5 percent bleeding rate,” Ng continued. [Surg Endosc 2010;24:1049-1054]

The researchers therefore see an urgent need to refine the ESD technology, with the use of robotics, for example, to address the increasing demand for ESD for early-stage CRC.

“In our preclinical study involving three ESD expert endoscopists, three ESD nonexpert endoscopists and three nonendoscopist novices, even novices were able to complete ESD procedures in porcine stomach models using the EndoMaster robotic system, with no perforation,” said Chiu. [Endosc Int Open 2015;3:E439-E442]

“Introduction of the second-generation flexible endoscopic robotic system may encourage more endoscopists to provide ESD for treatment of early gastrointestinal cancer in a safe manner,” Chiu suggested.

“The learning curve for ESD with the second-generation flexible endoscopic robotic system may be less steep compared with conventional ESD, but we need more data to confirm,” said Ng.