The future standard of care
BY ALEXIS BAYUDAN, MD, AND CRAIG A. MUNROE, MD
Endoscopic submucosal dissection (ESD) is a minimally invasive, organ-sparing, flexible endoscopic technique used to treat advanced neoplasia of the digestive tract, with the goal of en bloc resection for accurate histologic assessment. ESD was introduced over 25 years ago in Japan by a small group of innovative endoscopists.1 After its initial adoption and success with removing gastric lesions, ESD later evolved as a technique used for complete resection of lesions throughout the gastrointestinal tract.
The intent of ESD is to achieve clear pathologic evaluation of deep and lateral margins, which is generally lost when piecemeal EMR (pEMR) is performed on lesions larger than 2 cm. With growing global experience, the evidence is clear that ESD is advantageous when compared to pEMR in the resection of large colorectal lesions en bloc, leading to improved curative resection rates and less local recurrence.
Dr. Alexis Bayudan
From our own experience, and from the results of many studies, we know that although procedure time in ESD can be longer, the rate of complete resection is far superior. ESD was previously cited as having a 10% risk of perforation in the 1990s and early 2000s, but current rates are closer to 4.5%, as noted by Nimii et al., with nearly complete successful treatment with endoscopic closure.1 In a 2021 meta-analysis reviewing a total of 21 studies, Lim et. al demonstrate that, although there is an increased risk of perforation with ESD compared to EMR (risk ratio, 7.597; 95% confidence interval, 4.281-13.479; P < .001), there is no significant difference in bleeding risk between the two techniques (RR, 7.597; 95% CI, 4.281-13.479; P < .001).2
Since its inception, many refinements of the ESD technique have occurred through technology, and better understanding of anatomy and disease states. These include, but are not limited to, improvements in hemostatic and closure techniques, electrosurgical equipment, resection and traction devices, the use of carbon dioxide, the ability to perform full-thickness endoscopic surgery, and submucosal lifting.1 The realm of endoscopic innovation is moving at a rapid pace within commercial and noncommercial entities, and advancements in ESD devices will allow for further improvements in procedure times and decreased procedural complications. Conversely, there have been few advancements in EMR technique in decades.
Dr. Craig Munroe
Further developments in ESD will continue to democratize this intervention, so that it can be practiced in all medical centers, not just expert centers. However, for ESD to become standard of care in the Western world, it will require more exposure and training. ESD has rapidly spread throughout Japan because of the master-mentor relationship that fosters safe learning, in addition to an abundance of highly skilled EMR-experienced physicians who went on to acquire their skills under the supervision of ESD experts. Current methods of teaching ESD, such as using pig models to practice specific steps of the procedure, can be implemented in Western gastroenterology training programs and through GI and surgical society training programs to learn safe operation in the third space. Mentorship and proctorship are also mandatory. The incorporation of ESD into standard practice over pEMR is very akin to laparoscopic cholecystectomy revolutionizing gallbladder surgery, even though open cholecystectomy was known to be effective.
A major limitation in the adoption of ESD in the West is reimbursement. Despite mounting evidence of the superiority of ESD in well-trained hands, and the additional training needed to safely perform these procedures, there had not been a pathway forward for payment for the increased requirements needed to perform these procedures safely.3 This leads to more endoscopists performing pEMR in the West which is anti-innovative. In October 2021, the Centers for Medicare and Medicaid Services expanded the reimbursement for ESD (Healthcare Common Procedure Coding System C9779). The availability of billing codes paves the way for increasing patient access to these therapies. Hopefully, additional codes will follow.
With the mounting evidence demonstrating ESD is superior to pEMR in terms of curative resection and recurrence rates, we think it is time for ESD to be incorporated widely into Western practice. ESD is still evolving and improving; ESD will become both safer and more effective. ESD has revolutionized endoscopic resection, and we are just beginning to see the possibilities and value of these techniques.
Dr. Baydan is a second-year fellow, and Dr. Munroe is an associate professor, both at the University of California, San Francisco. They have no relevant conflicts of interest.
References
1. Ferreira J et al. Clin Colon Rectal Surg. 2015 Sep; 28(3):146-151.
2. Lim X et al. World J Gastroenterol. 2021 Jul 7;27(25):3925-39.
3. Iqbal S et al. World J Gastrointest Endosc. 2020 Jan 16; 12(1):49-52.
