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Will ESD replace EMR for large colorectal polyps?
Dear colleagues,
Resection of polyps is the bread and butter of endoscopy. Advances in technology have enabled us to tackle larger and more complex lesions throughout the gastrointestinal tract, especially through endoscopic mucosal resection (EMR). Endoscopic submucosal dissection (ESD) is another technique that offers much promise for complex colorectal polyps and is being rapidly adopted in the West. But do its benefits outweigh the costs in time, money and additional training needed for successful ESD? How can we justify higher recurrence rates with EMR when ESD is available? Will reimbursement continue to favor EMR? In this issue of Perspectives, Dr. Alexis Bayudan and Dr. Craig A. Munroe make the case for adopting ESD, while Dr. Sumeet Tewani highlights all the benefits of EMR. I invite you to a great debate and look forward to hearing your own thoughts on Twitter @AGA_GIHN and by email at ginews@gastro.org.
Gyanprakash A. Ketwaroo, MD, MSc, is assistant professor of medicine at Baylor College of Medicine, Houston. He is an associate editor for GI & Hepatology News.
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.
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.
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.
More investment than payoff
Most large colorectal polyps are best managed by endoscopic mucosal resection (EMR) and do not require endoscopic submucosal dissection (ESD). EMR can provide complete, safe, and effective removal, preventing colorectal cancer while avoiding the risks of surgery or ESD. EMR has several advantages over ESD. It is minimally invasive, low cost, well tolerated, and allows excellent histopathologic examination. It is performed during colonoscopy in an outpatient endoscopy lab or ambulatory surgery center. There are several techniques that can be performed safely and efficiently using accessories that are readily available. It is easier to learn and perform, with lower risks and fewer resources. Endoscopists can effectively integrate EMR into a busy practice, without making significant additional investments.
EMR of large adenomas has improved morbidity, mortality, and cost compared to surgery.1-3 I first carefully inspect the lesion to plan the approach and exclude submucosal invasion, which should be referred for ESD or surgery instead. This includes understanding the size, location, morphology, and surface characteristics, using high-definition and narrow-band imaging or Fujinon intelligent chromoendoscopy. Conventional EMR utilizes submucosal injection to lift the polyp away from the underlying muscle layer before hot snare resection. Injection needles and snares of various shapes, sizes, and stiffness are available in most endoscopy labs. The goal is en bloc resection to achieve potential cure with complete histological assessment and low rate of recurrence. This can be achieved for lesions up to 2 cm in size, although larger lesions require piecemeal resection, which limits accurate histopathology and carries a recurrence rate up to 25%.1 Thermal ablation of the resection margins with argon plasma coagulation or snare-tip soft coagulation can reduce the rate of recurrence. Additionally, most recurrences are identified during early surveillance within 6 months and managed endoscopically. The rates of adverse events, including bleeding (6%-15%), perforation (1%-2%), and postpolypectomy syndrome (< 1%) remain at acceptable low levels.1,4
For many polyps, saline injection is safe, effective, and inexpensive, but it dissipates rapidly with limited duration of effect. Alternative agents can improve the lift, at additional cost.4 I prefer adding dye, such as methylene blue, to differentiate the submucosa from the muscularis, demarcate the lesion margins, and allow easier inspection of the defect. Dilute epinephrine can also be added to reduce intraprocedural bleeding and maintain a clean resection field. I reserve this for the duodenum, but it can be an important adjunct for some colorectal polyps. Submucosal injection also allows assessment for a “nonlifting sign,” which raises suspicion for invasive carcinoma but can also occur with benign submucosal fibrosis from previous biopsy, partial resection, or adjacent tattoo. In these cases, effective management can still be achieved using EMR in combination with avulsion and thermal ablation techniques.
Alternative techniques include cold EMR and underwater EMR.1,4 These are gaining popularity because of their excellent safety profile and favorable outcomes. Cold EMR involves submucosal injection followed by cold-snare resection, eliminating the use of cautery and its associated risks. Cold EMR is very safe and effective for small polyps, and we use this for progressively larger polyps given the low complication rate. Despite the need for piecemeal resection of polyps larger than 10 mm, local recurrence rates are comparable to conventional EMR. Sessile serrated polyps are especially ideal for piecemeal cold EMR. Meanwhile, underwater EMR eliminates the need for submucosal injection by utilizing water immersion, which elevates the mucosal lesion away from the muscularis layer. Either hot or cold snare resection can be performed. Benefits include reduced procedure time and cost, and relatively low complication and recurrence rates, compared with conventional EMR. I find this to be a nice option for laterally spreading polyps, with potentially higher rates of en bloc resection.1,4
ESD involves similar techniques but includes careful dissection of the submucosal layer beneath the lesion. In addition to the tools for EMR, a specialized electrosurgical knife is necessary, as well as dedicated training and mentorship that can be difficult to accommodate for an active endoscopist in practice. The primary advantage of ESD is higher en bloc resection rates for larger and potentially deeper lesions, with accurate histologic assessment and staging, and very low recurrence rates.1,4,5 However, ESD is more complex, technically challenging, and time and resource intensive, with higher risk of complications. Intraprocedural bleeding is common and requires immediate management. Additional risks include 2% risk of delayed bleeding and 5% risk of perforation.1,5 ESD involves an operating room, longer procedure times, and higher cost including surgical, anesthesia, and nursing costs. Some of this may be balanced by reduced frequency of surveillance and therapeutic procedures. While both EMR and ESD carry significant cost savings, compared with surgery, ESD is additionally disadvantaged by lack of reimbursement.
Regardless of the technique, EMR is easier to learn and perform than ESD, uses a limited number of devices that are readily available, and carries lower cost-burden. EMR is successful for most colorectal polyps, with the primary disadvantage being piecemeal resection of larger polyps. The rates of adverse events are lower, and appropriate surveillance is essential to ensuring complete resection and eliminating recurrence. Japanese and European guidelines endorse ESD for lesions that have a high likelihood of cancer invading the submucosa and for lesions that cannot be removed by EMR because of submucosal fibrosis. Ultimately, patients need to be treated individually with the most appropriate technique.
Dr. Tewani of Rockford Gastroenterology Associates is clinical assistant professor of medicine at the University of Illinois, Rockford. He has no relevant conflicts of interest to disclose.
References
1. Rashid MU et al. Surg Oncol. 2022 Mar 18;101742.
2. Law R et al. Gastrointest Endosc. 2016 Jun;83(6):1248-57.
3. Backes Y et al. BMC Gastroenterol. 2016 May 26;16(1):56.
4. Thiruvengadam SS et al. Gastroenterol Hepatol. 2022 Mar;18(3):133-44.
5. Wang J et al. World J Gastroenterol. 2014 Jul 7;20(25):8282-7l.
Dear colleagues,
Resection of polyps is the bread and butter of endoscopy. Advances in technology have enabled us to tackle larger and more complex lesions throughout the gastrointestinal tract, especially through endoscopic mucosal resection (EMR). Endoscopic submucosal dissection (ESD) is another technique that offers much promise for complex colorectal polyps and is being rapidly adopted in the West. But do its benefits outweigh the costs in time, money and additional training needed for successful ESD? How can we justify higher recurrence rates with EMR when ESD is available? Will reimbursement continue to favor EMR? In this issue of Perspectives, Dr. Alexis Bayudan and Dr. Craig A. Munroe make the case for adopting ESD, while Dr. Sumeet Tewani highlights all the benefits of EMR. I invite you to a great debate and look forward to hearing your own thoughts on Twitter @AGA_GIHN and by email at ginews@gastro.org.
Gyanprakash A. Ketwaroo, MD, MSc, is assistant professor of medicine at Baylor College of Medicine, Houston. He is an associate editor for GI & Hepatology News.
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.
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.
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.
More investment than payoff
Most large colorectal polyps are best managed by endoscopic mucosal resection (EMR) and do not require endoscopic submucosal dissection (ESD). EMR can provide complete, safe, and effective removal, preventing colorectal cancer while avoiding the risks of surgery or ESD. EMR has several advantages over ESD. It is minimally invasive, low cost, well tolerated, and allows excellent histopathologic examination. It is performed during colonoscopy in an outpatient endoscopy lab or ambulatory surgery center. There are several techniques that can be performed safely and efficiently using accessories that are readily available. It is easier to learn and perform, with lower risks and fewer resources. Endoscopists can effectively integrate EMR into a busy practice, without making significant additional investments.
EMR of large adenomas has improved morbidity, mortality, and cost compared to surgery.1-3 I first carefully inspect the lesion to plan the approach and exclude submucosal invasion, which should be referred for ESD or surgery instead. This includes understanding the size, location, morphology, and surface characteristics, using high-definition and narrow-band imaging or Fujinon intelligent chromoendoscopy. Conventional EMR utilizes submucosal injection to lift the polyp away from the underlying muscle layer before hot snare resection. Injection needles and snares of various shapes, sizes, and stiffness are available in most endoscopy labs. The goal is en bloc resection to achieve potential cure with complete histological assessment and low rate of recurrence. This can be achieved for lesions up to 2 cm in size, although larger lesions require piecemeal resection, which limits accurate histopathology and carries a recurrence rate up to 25%.1 Thermal ablation of the resection margins with argon plasma coagulation or snare-tip soft coagulation can reduce the rate of recurrence. Additionally, most recurrences are identified during early surveillance within 6 months and managed endoscopically. The rates of adverse events, including bleeding (6%-15%), perforation (1%-2%), and postpolypectomy syndrome (< 1%) remain at acceptable low levels.1,4
For many polyps, saline injection is safe, effective, and inexpensive, but it dissipates rapidly with limited duration of effect. Alternative agents can improve the lift, at additional cost.4 I prefer adding dye, such as methylene blue, to differentiate the submucosa from the muscularis, demarcate the lesion margins, and allow easier inspection of the defect. Dilute epinephrine can also be added to reduce intraprocedural bleeding and maintain a clean resection field. I reserve this for the duodenum, but it can be an important adjunct for some colorectal polyps. Submucosal injection also allows assessment for a “nonlifting sign,” which raises suspicion for invasive carcinoma but can also occur with benign submucosal fibrosis from previous biopsy, partial resection, or adjacent tattoo. In these cases, effective management can still be achieved using EMR in combination with avulsion and thermal ablation techniques.
Alternative techniques include cold EMR and underwater EMR.1,4 These are gaining popularity because of their excellent safety profile and favorable outcomes. Cold EMR involves submucosal injection followed by cold-snare resection, eliminating the use of cautery and its associated risks. Cold EMR is very safe and effective for small polyps, and we use this for progressively larger polyps given the low complication rate. Despite the need for piecemeal resection of polyps larger than 10 mm, local recurrence rates are comparable to conventional EMR. Sessile serrated polyps are especially ideal for piecemeal cold EMR. Meanwhile, underwater EMR eliminates the need for submucosal injection by utilizing water immersion, which elevates the mucosal lesion away from the muscularis layer. Either hot or cold snare resection can be performed. Benefits include reduced procedure time and cost, and relatively low complication and recurrence rates, compared with conventional EMR. I find this to be a nice option for laterally spreading polyps, with potentially higher rates of en bloc resection.1,4
ESD involves similar techniques but includes careful dissection of the submucosal layer beneath the lesion. In addition to the tools for EMR, a specialized electrosurgical knife is necessary, as well as dedicated training and mentorship that can be difficult to accommodate for an active endoscopist in practice. The primary advantage of ESD is higher en bloc resection rates for larger and potentially deeper lesions, with accurate histologic assessment and staging, and very low recurrence rates.1,4,5 However, ESD is more complex, technically challenging, and time and resource intensive, with higher risk of complications. Intraprocedural bleeding is common and requires immediate management. Additional risks include 2% risk of delayed bleeding and 5% risk of perforation.1,5 ESD involves an operating room, longer procedure times, and higher cost including surgical, anesthesia, and nursing costs. Some of this may be balanced by reduced frequency of surveillance and therapeutic procedures. While both EMR and ESD carry significant cost savings, compared with surgery, ESD is additionally disadvantaged by lack of reimbursement.
Regardless of the technique, EMR is easier to learn and perform than ESD, uses a limited number of devices that are readily available, and carries lower cost-burden. EMR is successful for most colorectal polyps, with the primary disadvantage being piecemeal resection of larger polyps. The rates of adverse events are lower, and appropriate surveillance is essential to ensuring complete resection and eliminating recurrence. Japanese and European guidelines endorse ESD for lesions that have a high likelihood of cancer invading the submucosa and for lesions that cannot be removed by EMR because of submucosal fibrosis. Ultimately, patients need to be treated individually with the most appropriate technique.
Dr. Tewani of Rockford Gastroenterology Associates is clinical assistant professor of medicine at the University of Illinois, Rockford. He has no relevant conflicts of interest to disclose.
References
1. Rashid MU et al. Surg Oncol. 2022 Mar 18;101742.
2. Law R et al. Gastrointest Endosc. 2016 Jun;83(6):1248-57.
3. Backes Y et al. BMC Gastroenterol. 2016 May 26;16(1):56.
4. Thiruvengadam SS et al. Gastroenterol Hepatol. 2022 Mar;18(3):133-44.
5. Wang J et al. World J Gastroenterol. 2014 Jul 7;20(25):8282-7l.
Dear colleagues,
Resection of polyps is the bread and butter of endoscopy. Advances in technology have enabled us to tackle larger and more complex lesions throughout the gastrointestinal tract, especially through endoscopic mucosal resection (EMR). Endoscopic submucosal dissection (ESD) is another technique that offers much promise for complex colorectal polyps and is being rapidly adopted in the West. But do its benefits outweigh the costs in time, money and additional training needed for successful ESD? How can we justify higher recurrence rates with EMR when ESD is available? Will reimbursement continue to favor EMR? In this issue of Perspectives, Dr. Alexis Bayudan and Dr. Craig A. Munroe make the case for adopting ESD, while Dr. Sumeet Tewani highlights all the benefits of EMR. I invite you to a great debate and look forward to hearing your own thoughts on Twitter @AGA_GIHN and by email at ginews@gastro.org.
Gyanprakash A. Ketwaroo, MD, MSc, is assistant professor of medicine at Baylor College of Medicine, Houston. He is an associate editor for GI & Hepatology News.
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.
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.
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.
More investment than payoff
Most large colorectal polyps are best managed by endoscopic mucosal resection (EMR) and do not require endoscopic submucosal dissection (ESD). EMR can provide complete, safe, and effective removal, preventing colorectal cancer while avoiding the risks of surgery or ESD. EMR has several advantages over ESD. It is minimally invasive, low cost, well tolerated, and allows excellent histopathologic examination. It is performed during colonoscopy in an outpatient endoscopy lab or ambulatory surgery center. There are several techniques that can be performed safely and efficiently using accessories that are readily available. It is easier to learn and perform, with lower risks and fewer resources. Endoscopists can effectively integrate EMR into a busy practice, without making significant additional investments.
EMR of large adenomas has improved morbidity, mortality, and cost compared to surgery.1-3 I first carefully inspect the lesion to plan the approach and exclude submucosal invasion, which should be referred for ESD or surgery instead. This includes understanding the size, location, morphology, and surface characteristics, using high-definition and narrow-band imaging or Fujinon intelligent chromoendoscopy. Conventional EMR utilizes submucosal injection to lift the polyp away from the underlying muscle layer before hot snare resection. Injection needles and snares of various shapes, sizes, and stiffness are available in most endoscopy labs. The goal is en bloc resection to achieve potential cure with complete histological assessment and low rate of recurrence. This can be achieved for lesions up to 2 cm in size, although larger lesions require piecemeal resection, which limits accurate histopathology and carries a recurrence rate up to 25%.1 Thermal ablation of the resection margins with argon plasma coagulation or snare-tip soft coagulation can reduce the rate of recurrence. Additionally, most recurrences are identified during early surveillance within 6 months and managed endoscopically. The rates of adverse events, including bleeding (6%-15%), perforation (1%-2%), and postpolypectomy syndrome (< 1%) remain at acceptable low levels.1,4
For many polyps, saline injection is safe, effective, and inexpensive, but it dissipates rapidly with limited duration of effect. Alternative agents can improve the lift, at additional cost.4 I prefer adding dye, such as methylene blue, to differentiate the submucosa from the muscularis, demarcate the lesion margins, and allow easier inspection of the defect. Dilute epinephrine can also be added to reduce intraprocedural bleeding and maintain a clean resection field. I reserve this for the duodenum, but it can be an important adjunct for some colorectal polyps. Submucosal injection also allows assessment for a “nonlifting sign,” which raises suspicion for invasive carcinoma but can also occur with benign submucosal fibrosis from previous biopsy, partial resection, or adjacent tattoo. In these cases, effective management can still be achieved using EMR in combination with avulsion and thermal ablation techniques.
Alternative techniques include cold EMR and underwater EMR.1,4 These are gaining popularity because of their excellent safety profile and favorable outcomes. Cold EMR involves submucosal injection followed by cold-snare resection, eliminating the use of cautery and its associated risks. Cold EMR is very safe and effective for small polyps, and we use this for progressively larger polyps given the low complication rate. Despite the need for piecemeal resection of polyps larger than 10 mm, local recurrence rates are comparable to conventional EMR. Sessile serrated polyps are especially ideal for piecemeal cold EMR. Meanwhile, underwater EMR eliminates the need for submucosal injection by utilizing water immersion, which elevates the mucosal lesion away from the muscularis layer. Either hot or cold snare resection can be performed. Benefits include reduced procedure time and cost, and relatively low complication and recurrence rates, compared with conventional EMR. I find this to be a nice option for laterally spreading polyps, with potentially higher rates of en bloc resection.1,4
ESD involves similar techniques but includes careful dissection of the submucosal layer beneath the lesion. In addition to the tools for EMR, a specialized electrosurgical knife is necessary, as well as dedicated training and mentorship that can be difficult to accommodate for an active endoscopist in practice. The primary advantage of ESD is higher en bloc resection rates for larger and potentially deeper lesions, with accurate histologic assessment and staging, and very low recurrence rates.1,4,5 However, ESD is more complex, technically challenging, and time and resource intensive, with higher risk of complications. Intraprocedural bleeding is common and requires immediate management. Additional risks include 2% risk of delayed bleeding and 5% risk of perforation.1,5 ESD involves an operating room, longer procedure times, and higher cost including surgical, anesthesia, and nursing costs. Some of this may be balanced by reduced frequency of surveillance and therapeutic procedures. While both EMR and ESD carry significant cost savings, compared with surgery, ESD is additionally disadvantaged by lack of reimbursement.
Regardless of the technique, EMR is easier to learn and perform than ESD, uses a limited number of devices that are readily available, and carries lower cost-burden. EMR is successful for most colorectal polyps, with the primary disadvantage being piecemeal resection of larger polyps. The rates of adverse events are lower, and appropriate surveillance is essential to ensuring complete resection and eliminating recurrence. Japanese and European guidelines endorse ESD for lesions that have a high likelihood of cancer invading the submucosa and for lesions that cannot be removed by EMR because of submucosal fibrosis. Ultimately, patients need to be treated individually with the most appropriate technique.
Dr. Tewani of Rockford Gastroenterology Associates is clinical assistant professor of medicine at the University of Illinois, Rockford. He has no relevant conflicts of interest to disclose.
References
1. Rashid MU et al. Surg Oncol. 2022 Mar 18;101742.
2. Law R et al. Gastrointest Endosc. 2016 Jun;83(6):1248-57.
3. Backes Y et al. BMC Gastroenterol. 2016 May 26;16(1):56.
4. Thiruvengadam SS et al. Gastroenterol Hepatol. 2022 Mar;18(3):133-44.
5. Wang J et al. World J Gastroenterol. 2014 Jul 7;20(25):8282-7l.
