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Dear colleagues,
We now have the ability to remove almost any large colon polyp endoscopically using a variety of techniques — from the widely used endoscopic mucosal resection to the increasingly prevalent endoscopic submucosal dissection. Yet, in this new era,
In this issue of Perspectives, Dr. Jeffrey Mosko and Dr. Moamen Gabr discuss the importance of careful polyp selection and argue that almost all polyps can be safely removed endoscopically, with low recurrence rates. In contrast, Dr. Ira Leeds from colorectal surgery offers a counterpoint, urging caution when managing polyps in the cecum and rectum while highlighting the role of minimally invasive surgical approaches. We hope these discussions provide valuable insights to support your approach to managing large colorectal polyps, especially in an era of increasing colon cancer screening.
We also welcome your thoughts on this topic — join the conversation on X at @AGA_GIHN.
Gyanprakash A. Ketwaroo, MD, MSc, is associate professor of medicine, Yale University, New Haven, and chief of endoscopy at West Haven VA Medical Center, both in Connecticut. He is an associate editor for GI & Hepatology News.
Advantages of Endoscopic Resection for Large Colon Polyps
BY MOAMEN GABR, MD, MSC, AND JEFFREY D. MOSKO MD, MSC
General Advantages
Endoscopy has revolutionized the management of large colorectal polyps, offering a minimally invasive alternative to surgical resection. The dawn of endoscopic resection in the late 20th century, particularly the evolution of endoscopic mucosal resection (EMR) in Japan, marked a paradigm shift in the treatment of colonic lesions by enabling the removal of lesions that would otherwise necessitate surgery.
Endoscopic resection of colorectal polyps is generally performed in an outpatient setting, allowing patients to recover at home the same day. This not only minimizes disruption to daily life but also significantly enhances patient satisfaction.
Most procedures are performed under moderate or deep sedation eliminating the need for general anesthesia. This represents a critical benefit, particularly for older or medically frail patients who are at higher risk of anesthesia-related complications.
From an economic perspective, endoscopic resection reduces healthcare costs by eliminating prolonged hospital stays and complex perioperative care. Additionally, preserving the colon’s structure and function avoids long-term consequences such as altered bowel habits or ostomy dependence, common with surgical interventions.
The advantages of endoscopic intervention are clear: safety, cost-effectiveness, organ preservation, and convenience for patients.
Lesion Selection
The superiority of endoscopic resection relies on selecting lesions appropriately, specifically those with a low risk of lymph node metastases. This meticulous process should include assessing a lesion’s size, location, morphology, granularity, microvascular and surface pit pattern using a combination of high-definition white light endoscopy, virtual chromoendoscopy and image magnification (when available).
Gross morphologic assessment utilizes the Paris and LST classifications. Combining the Paris classification, lesion granularity and location is both straightforward and revealing. Ulcerated/excavated lesions (0-III) are concerning for deep invasion. Depressed (0-IIc) morphologies are strongly associated with T1 CRC. Nodular lesions (0-Is or IIa + Is) have a higher risk of T1 colorectal cancer (CRC), compared with flat lesions (0-IIa or 0-IIb). Non-granular lesions (0-Is and 0-IIa + Is) have a higher risk of covert cancer. Finally, the rectosigmoid location is associated with an increased risk of T1 CRC (vs. proximal locations).
Endoscopic surface pattern assessment increases one’s diagnostic accuracy. There are three primary endoscopic surface pattern classifications: NBI International Colorectal Endoscopic (NICE), Japanese NBI expert team (JNET), and Kudo pit pattern classifications. Colonic lesions that have a NICE Type 3, JNET 3, or Kudo type Vn pattern should be referred promptly for surgical resection. Lesions with a JNET 2B or Kudo type VI carry a higher risk of superficial T1 CRC but can still be removed endoscopically (see below) in expert centers. All other lesions should undergo endoscopic resection.
Endoscopic Resection Techniques
Endoscopic resection of large colorectal polyps encompasses two primary techniques: EMR and endoscopic submucosal dissection (ESD), each tailored to specific lesion characteristics and operator expertise.
EMR, the technique of choice for the vast majority of lesions, relies on injecting a submucosal cushion to lift the lesion before excision. Recent advances, including enhanced snare designs and underwater EMR, have improved en-bloc resection rates, significantly reducing recurrence and enhancing the efficacy of this technique.
ESD offers unparalleled precision for en-bloc resection of complex lesions, particularly those with fibrosis or high-risk features. Cutting-edge innovations, such as traction devices, have streamlined the procedure, addressing the traditional challenges of ESD. Despite being more time intensive, ESD minimizes recurrence and provides complete histopathological evaluation, critical for the management of malignant or pre-malignant lesions.
For non-lifting polyps, newer techniques such as endoscopic full-thickness resection (eFTR), using tools like the Full-Thickness Resection Device (FTRD), enable resection of up to 2-3 cm of the colonic or rectal wall. This ensures complete removal of any lesion and its underlying tissue, effectively preventing recurrence.
These advancements demonstrate how endoscopy can tackle even the most challenging colorectal polyps, reinforcing its position as the preferred treatment modality.
Perceived Limitations
With ongoing refinement over the last 2 decades, many of the perceived limitations (below) of endoscopic resection have now been overcome.
- Difficult locations/access: Historically lesions at the anorectal junction, ileocecal valve, appendiceal orifice and anastomoses were preferentially sent for surgery. In spite of unique technical challenges at each of these locations, there is now compelling data supporting EMR for these scenarios. We now also have techniques aimed at enabling the resection of lesions with poor access including patient repositioning, distal attachments, variable endoscope diameter/flexibility, traction and overtube devices.
- Recurrence: In the past, recurrence after endoscopic resection of lesions > 20 mm has been reported to be as high as 20%. With our current systematic approach to complete resection, meticulous examination of the post-resection defect for residual polyp tissue, adjunctive techniques to address submucosal fibrosis (hot avulsion, CAST, submucosal release) and thermal ablation to the resection margin (EMR-T), the risk of recurrence for piecemeal resections can be decreased to < 5%. In fact, some groups argue for the en-bloc resection of all large colorectal lesions based on the extremely low (< 1%) recurrence rates and potential for decreased follow-up.
- Post-resection bleeding: Post-resection bleeding is no longer a major limitation of any endoscopic approach because of the combination of improved intra-procedural hemostatic and resection techniques, optimized electrosurgical technology, and enhanced defect closure capabilities and devices (with prophylactic defect closure now supported by randomized control trial level data).
- Perforation: Deep mural injury, once an endoscopists’ worst fear during resection, is no longer a surgical emergency. It can now be predicted, identified (Sydney classification) and successfully managed. In spite of more widespread aggressive resection strategies, the risk of emergency surgery in patients undergoing EMR and even ESD (where the risk of DMI is significantly higher) is extremely low.
Endoscopic resection for large colorectal polyps is effective, available, minimally invasive and organ sparing making it the standard of care for the management of colonic polyps. With ongoing iteration in techniques, more invasive surgical approaches can be avoided in almost all patients with benign and low-risk T1 colorectal cancers.
Dr. Gabr is associate GI division director at the University of Cincinnati, Ohio. Dr. Mosko is based in the division of gastroenterology at St. Michael’s Hospital, Toronto, Ontario, Canada. The authors declare no conflicts of interest.
Blurred Lines: Polyp Needing Surgical versus Endoscopic Excision
BY IRA LEEDS, MD
I am grateful for the invitation to join in discussion with Dr. Gabr and Dr. Mosko on the ever-increasing role of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). However, as a surgeon, I do carry at least mild trepidation entering one of the literary “safe spaces” of my gastroenterology colleagues.
With the increasing evidentiary support of EMR approaches and the increasing experience of those performing ESD, these two techniques are quickly becoming the options of choice. As these practices become ubiquitous, it is important to recognize both their advantages and limitations, compared with available surgical options. The decision to proceed with EMR and ESD is essentially a turning point away from early surgical referral for a complex lesion. In this discussion, I intend to highlight when EMR and ESD have a clear advantage to early surgical referral, why I believe that early surgical referral is still superior to advanced endoscopic techniques in the rectum, and why the approach for right-sided lesions should hinge on careful shared decision-making.
Endoscopic approaches nearly always beat surgical approaches when considering short-term risks. Even in the best surgical series, colorectal surgery typically leads to complications in 10%-15% of patients, 1%-5% being serious. Moreover, transabdominal surgical interventions (ie, colectomy) require considerable recovery involving at least a few days in the inpatient setting and over a month of activity restrictions. Finally, there is a minority of chronically unwell patients who cannot tolerate surgical intervention but may be fortunate enough to have a lesion that with enhanced attention can be endoscopically resectioned. While EMR and ESD also contribute a disproportionate burden of complications to endoscopy practice, overall complication rates are still favorable when compared with surgical resection.
Moreover, the most feared short-term complication of EMR and ESD, perforation, has the added benefit of a “controlled failure” to colectomy. Advanced endoscopic approaches already require a prepared colon, and patients are given strict return instructions. Hence, the yearly handful of postprocedural perforations that I get called upon to assist with typically tolerate a routine surgical exploration, repair or resection, and recover at rates equal to or better than elective colon resections. For these reasons, lesions that can be endoscopically removed within appropriate risk tolerances, can and should be considered for EMR or ESD at time of diagnosis.
There are two clinical scenarios where this consideration for up-front EMR or ESD requires further caution. First, any rectal lesion considered for advanced endoscopic techniques really needs to be done in multidisciplinary conference with a colorectal surgeon. In the modern era of colorectal surgery, surgeons now have numerous approaches to reach the rectum that bridge the gap between traditional endoscopy and transabdominal resection. For many rectal lesions, transanal laparoscopic and robotic approaches offer the opportunity for local excision. The most commonly practiced approach, transanal minimally invasive microsurgery (TAMIS), provides many of the benefits of endoscopy (eg, same-day discharge, no activity restrictions, limited periprocedural physiologic stress, low complication rates) while providing the surgical precision, repair strategies, and specimen orientation of conventional surgery. Anecdotally, the time it takes to do a high-quality TAMIS excision in the rectum can be substantially less than that required for a comparable ESD.
For rectal lesions in particular, specimen quality is paramount for oncologic prognosis. Regardless of any intrinsic favorable histopathology or deft hand of the endoscopist, a TAMIS approach will typically provide for a deeper partial thickness or even full thickness excision. More times each year than I would like, I find myself at a multidisciplinary tumor board discussing an endoscopically removed rectal lesion done in a piecemeal fashion or insufficient deep ESD where appropriate risk stratification is impossible and we end up offering patients a likely overly aggressive proctectomy or a potentially oncologically unsound re-excision. Consideration of EMR/ESD vs TAMIS up front would allow better sorting of which technique is most suited to which lesion and avoid these diagnostic dilemmas that only seem to be more common as EMR and ESD practices proliferate.
For a different set of reasons, an advanced cecal adenoma may also be more suited to upfront surgical considerations. Right colon lesions can be more challenging for surveillance for a host of reasons. Procedurally, right colon lesions are undeniably more difficult. The thin-walled cecum can be unforgiving for repeated polypectomies. Despite it being an uncomfortable subject for colonoscopists, the evidence suggests that getting to the cecum is not consistent or 100% expected. Finally, patients can be unwilling to undergo serial bowel preparation and endoscopic examination. In contrast, a laparoscopic right colectomy avoids these issues while also attributing little additional risk. Laparoscopic right-colon operations have overall complication rates of less than 10% and major complications of less than 1%. Hospital stays for laparoscopic right colectomy are typically 3 days or less. Finally, surgery reduces both the frequency of surveillance, and a shortened colon makes surveillance easier.
Advanced polypectomy techniques broaden our ability to address even difficult lesions under the ideally aligned degree of invasive procedure. However, like any procedure, these techniques have their own advantages and limitations. There will always be a minority of premalignant colon lesions that are best suited to surgery-first approaches to treatment. In my practice, maintaining open lines of communication and regular interaction with my endoscopy colleagues naturally leads to polyps being addressed in their most suitable fashion.
Dr. Leeds is assistant professor of surgery at the Yale School of Medicine and a staff surgeon at the VA Connecticut Healthcare System. He declares no conflicts of interest.
Dear colleagues,
We now have the ability to remove almost any large colon polyp endoscopically using a variety of techniques — from the widely used endoscopic mucosal resection to the increasingly prevalent endoscopic submucosal dissection. Yet, in this new era,
In this issue of Perspectives, Dr. Jeffrey Mosko and Dr. Moamen Gabr discuss the importance of careful polyp selection and argue that almost all polyps can be safely removed endoscopically, with low recurrence rates. In contrast, Dr. Ira Leeds from colorectal surgery offers a counterpoint, urging caution when managing polyps in the cecum and rectum while highlighting the role of minimally invasive surgical approaches. We hope these discussions provide valuable insights to support your approach to managing large colorectal polyps, especially in an era of increasing colon cancer screening.
We also welcome your thoughts on this topic — join the conversation on X at @AGA_GIHN.
Gyanprakash A. Ketwaroo, MD, MSc, is associate professor of medicine, Yale University, New Haven, and chief of endoscopy at West Haven VA Medical Center, both in Connecticut. He is an associate editor for GI & Hepatology News.
Advantages of Endoscopic Resection for Large Colon Polyps
BY MOAMEN GABR, MD, MSC, AND JEFFREY D. MOSKO MD, MSC
General Advantages
Endoscopy has revolutionized the management of large colorectal polyps, offering a minimally invasive alternative to surgical resection. The dawn of endoscopic resection in the late 20th century, particularly the evolution of endoscopic mucosal resection (EMR) in Japan, marked a paradigm shift in the treatment of colonic lesions by enabling the removal of lesions that would otherwise necessitate surgery.
Endoscopic resection of colorectal polyps is generally performed in an outpatient setting, allowing patients to recover at home the same day. This not only minimizes disruption to daily life but also significantly enhances patient satisfaction.
Most procedures are performed under moderate or deep sedation eliminating the need for general anesthesia. This represents a critical benefit, particularly for older or medically frail patients who are at higher risk of anesthesia-related complications.
From an economic perspective, endoscopic resection reduces healthcare costs by eliminating prolonged hospital stays and complex perioperative care. Additionally, preserving the colon’s structure and function avoids long-term consequences such as altered bowel habits or ostomy dependence, common with surgical interventions.
The advantages of endoscopic intervention are clear: safety, cost-effectiveness, organ preservation, and convenience for patients.
Lesion Selection
The superiority of endoscopic resection relies on selecting lesions appropriately, specifically those with a low risk of lymph node metastases. This meticulous process should include assessing a lesion’s size, location, morphology, granularity, microvascular and surface pit pattern using a combination of high-definition white light endoscopy, virtual chromoendoscopy and image magnification (when available).
Gross morphologic assessment utilizes the Paris and LST classifications. Combining the Paris classification, lesion granularity and location is both straightforward and revealing. Ulcerated/excavated lesions (0-III) are concerning for deep invasion. Depressed (0-IIc) morphologies are strongly associated with T1 CRC. Nodular lesions (0-Is or IIa + Is) have a higher risk of T1 colorectal cancer (CRC), compared with flat lesions (0-IIa or 0-IIb). Non-granular lesions (0-Is and 0-IIa + Is) have a higher risk of covert cancer. Finally, the rectosigmoid location is associated with an increased risk of T1 CRC (vs. proximal locations).
Endoscopic surface pattern assessment increases one’s diagnostic accuracy. There are three primary endoscopic surface pattern classifications: NBI International Colorectal Endoscopic (NICE), Japanese NBI expert team (JNET), and Kudo pit pattern classifications. Colonic lesions that have a NICE Type 3, JNET 3, or Kudo type Vn pattern should be referred promptly for surgical resection. Lesions with a JNET 2B or Kudo type VI carry a higher risk of superficial T1 CRC but can still be removed endoscopically (see below) in expert centers. All other lesions should undergo endoscopic resection.
Endoscopic Resection Techniques
Endoscopic resection of large colorectal polyps encompasses two primary techniques: EMR and endoscopic submucosal dissection (ESD), each tailored to specific lesion characteristics and operator expertise.
EMR, the technique of choice for the vast majority of lesions, relies on injecting a submucosal cushion to lift the lesion before excision. Recent advances, including enhanced snare designs and underwater EMR, have improved en-bloc resection rates, significantly reducing recurrence and enhancing the efficacy of this technique.
ESD offers unparalleled precision for en-bloc resection of complex lesions, particularly those with fibrosis or high-risk features. Cutting-edge innovations, such as traction devices, have streamlined the procedure, addressing the traditional challenges of ESD. Despite being more time intensive, ESD minimizes recurrence and provides complete histopathological evaluation, critical for the management of malignant or pre-malignant lesions.
For non-lifting polyps, newer techniques such as endoscopic full-thickness resection (eFTR), using tools like the Full-Thickness Resection Device (FTRD), enable resection of up to 2-3 cm of the colonic or rectal wall. This ensures complete removal of any lesion and its underlying tissue, effectively preventing recurrence.
These advancements demonstrate how endoscopy can tackle even the most challenging colorectal polyps, reinforcing its position as the preferred treatment modality.
Perceived Limitations
With ongoing refinement over the last 2 decades, many of the perceived limitations (below) of endoscopic resection have now been overcome.
- Difficult locations/access: Historically lesions at the anorectal junction, ileocecal valve, appendiceal orifice and anastomoses were preferentially sent for surgery. In spite of unique technical challenges at each of these locations, there is now compelling data supporting EMR for these scenarios. We now also have techniques aimed at enabling the resection of lesions with poor access including patient repositioning, distal attachments, variable endoscope diameter/flexibility, traction and overtube devices.
- Recurrence: In the past, recurrence after endoscopic resection of lesions > 20 mm has been reported to be as high as 20%. With our current systematic approach to complete resection, meticulous examination of the post-resection defect for residual polyp tissue, adjunctive techniques to address submucosal fibrosis (hot avulsion, CAST, submucosal release) and thermal ablation to the resection margin (EMR-T), the risk of recurrence for piecemeal resections can be decreased to < 5%. In fact, some groups argue for the en-bloc resection of all large colorectal lesions based on the extremely low (< 1%) recurrence rates and potential for decreased follow-up.
- Post-resection bleeding: Post-resection bleeding is no longer a major limitation of any endoscopic approach because of the combination of improved intra-procedural hemostatic and resection techniques, optimized electrosurgical technology, and enhanced defect closure capabilities and devices (with prophylactic defect closure now supported by randomized control trial level data).
- Perforation: Deep mural injury, once an endoscopists’ worst fear during resection, is no longer a surgical emergency. It can now be predicted, identified (Sydney classification) and successfully managed. In spite of more widespread aggressive resection strategies, the risk of emergency surgery in patients undergoing EMR and even ESD (where the risk of DMI is significantly higher) is extremely low.
Endoscopic resection for large colorectal polyps is effective, available, minimally invasive and organ sparing making it the standard of care for the management of colonic polyps. With ongoing iteration in techniques, more invasive surgical approaches can be avoided in almost all patients with benign and low-risk T1 colorectal cancers.
Dr. Gabr is associate GI division director at the University of Cincinnati, Ohio. Dr. Mosko is based in the division of gastroenterology at St. Michael’s Hospital, Toronto, Ontario, Canada. The authors declare no conflicts of interest.
Blurred Lines: Polyp Needing Surgical versus Endoscopic Excision
BY IRA LEEDS, MD
I am grateful for the invitation to join in discussion with Dr. Gabr and Dr. Mosko on the ever-increasing role of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). However, as a surgeon, I do carry at least mild trepidation entering one of the literary “safe spaces” of my gastroenterology colleagues.
With the increasing evidentiary support of EMR approaches and the increasing experience of those performing ESD, these two techniques are quickly becoming the options of choice. As these practices become ubiquitous, it is important to recognize both their advantages and limitations, compared with available surgical options. The decision to proceed with EMR and ESD is essentially a turning point away from early surgical referral for a complex lesion. In this discussion, I intend to highlight when EMR and ESD have a clear advantage to early surgical referral, why I believe that early surgical referral is still superior to advanced endoscopic techniques in the rectum, and why the approach for right-sided lesions should hinge on careful shared decision-making.
Endoscopic approaches nearly always beat surgical approaches when considering short-term risks. Even in the best surgical series, colorectal surgery typically leads to complications in 10%-15% of patients, 1%-5% being serious. Moreover, transabdominal surgical interventions (ie, colectomy) require considerable recovery involving at least a few days in the inpatient setting and over a month of activity restrictions. Finally, there is a minority of chronically unwell patients who cannot tolerate surgical intervention but may be fortunate enough to have a lesion that with enhanced attention can be endoscopically resectioned. While EMR and ESD also contribute a disproportionate burden of complications to endoscopy practice, overall complication rates are still favorable when compared with surgical resection.
Moreover, the most feared short-term complication of EMR and ESD, perforation, has the added benefit of a “controlled failure” to colectomy. Advanced endoscopic approaches already require a prepared colon, and patients are given strict return instructions. Hence, the yearly handful of postprocedural perforations that I get called upon to assist with typically tolerate a routine surgical exploration, repair or resection, and recover at rates equal to or better than elective colon resections. For these reasons, lesions that can be endoscopically removed within appropriate risk tolerances, can and should be considered for EMR or ESD at time of diagnosis.
There are two clinical scenarios where this consideration for up-front EMR or ESD requires further caution. First, any rectal lesion considered for advanced endoscopic techniques really needs to be done in multidisciplinary conference with a colorectal surgeon. In the modern era of colorectal surgery, surgeons now have numerous approaches to reach the rectum that bridge the gap between traditional endoscopy and transabdominal resection. For many rectal lesions, transanal laparoscopic and robotic approaches offer the opportunity for local excision. The most commonly practiced approach, transanal minimally invasive microsurgery (TAMIS), provides many of the benefits of endoscopy (eg, same-day discharge, no activity restrictions, limited periprocedural physiologic stress, low complication rates) while providing the surgical precision, repair strategies, and specimen orientation of conventional surgery. Anecdotally, the time it takes to do a high-quality TAMIS excision in the rectum can be substantially less than that required for a comparable ESD.
For rectal lesions in particular, specimen quality is paramount for oncologic prognosis. Regardless of any intrinsic favorable histopathology or deft hand of the endoscopist, a TAMIS approach will typically provide for a deeper partial thickness or even full thickness excision. More times each year than I would like, I find myself at a multidisciplinary tumor board discussing an endoscopically removed rectal lesion done in a piecemeal fashion or insufficient deep ESD where appropriate risk stratification is impossible and we end up offering patients a likely overly aggressive proctectomy or a potentially oncologically unsound re-excision. Consideration of EMR/ESD vs TAMIS up front would allow better sorting of which technique is most suited to which lesion and avoid these diagnostic dilemmas that only seem to be more common as EMR and ESD practices proliferate.
For a different set of reasons, an advanced cecal adenoma may also be more suited to upfront surgical considerations. Right colon lesions can be more challenging for surveillance for a host of reasons. Procedurally, right colon lesions are undeniably more difficult. The thin-walled cecum can be unforgiving for repeated polypectomies. Despite it being an uncomfortable subject for colonoscopists, the evidence suggests that getting to the cecum is not consistent or 100% expected. Finally, patients can be unwilling to undergo serial bowel preparation and endoscopic examination. In contrast, a laparoscopic right colectomy avoids these issues while also attributing little additional risk. Laparoscopic right-colon operations have overall complication rates of less than 10% and major complications of less than 1%. Hospital stays for laparoscopic right colectomy are typically 3 days or less. Finally, surgery reduces both the frequency of surveillance, and a shortened colon makes surveillance easier.
Advanced polypectomy techniques broaden our ability to address even difficult lesions under the ideally aligned degree of invasive procedure. However, like any procedure, these techniques have their own advantages and limitations. There will always be a minority of premalignant colon lesions that are best suited to surgery-first approaches to treatment. In my practice, maintaining open lines of communication and regular interaction with my endoscopy colleagues naturally leads to polyps being addressed in their most suitable fashion.
Dr. Leeds is assistant professor of surgery at the Yale School of Medicine and a staff surgeon at the VA Connecticut Healthcare System. He declares no conflicts of interest.
Dear colleagues,
We now have the ability to remove almost any large colon polyp endoscopically using a variety of techniques — from the widely used endoscopic mucosal resection to the increasingly prevalent endoscopic submucosal dissection. Yet, in this new era,
In this issue of Perspectives, Dr. Jeffrey Mosko and Dr. Moamen Gabr discuss the importance of careful polyp selection and argue that almost all polyps can be safely removed endoscopically, with low recurrence rates. In contrast, Dr. Ira Leeds from colorectal surgery offers a counterpoint, urging caution when managing polyps in the cecum and rectum while highlighting the role of minimally invasive surgical approaches. We hope these discussions provide valuable insights to support your approach to managing large colorectal polyps, especially in an era of increasing colon cancer screening.
We also welcome your thoughts on this topic — join the conversation on X at @AGA_GIHN.
Gyanprakash A. Ketwaroo, MD, MSc, is associate professor of medicine, Yale University, New Haven, and chief of endoscopy at West Haven VA Medical Center, both in Connecticut. He is an associate editor for GI & Hepatology News.
Advantages of Endoscopic Resection for Large Colon Polyps
BY MOAMEN GABR, MD, MSC, AND JEFFREY D. MOSKO MD, MSC
General Advantages
Endoscopy has revolutionized the management of large colorectal polyps, offering a minimally invasive alternative to surgical resection. The dawn of endoscopic resection in the late 20th century, particularly the evolution of endoscopic mucosal resection (EMR) in Japan, marked a paradigm shift in the treatment of colonic lesions by enabling the removal of lesions that would otherwise necessitate surgery.
Endoscopic resection of colorectal polyps is generally performed in an outpatient setting, allowing patients to recover at home the same day. This not only minimizes disruption to daily life but also significantly enhances patient satisfaction.
Most procedures are performed under moderate or deep sedation eliminating the need for general anesthesia. This represents a critical benefit, particularly for older or medically frail patients who are at higher risk of anesthesia-related complications.
From an economic perspective, endoscopic resection reduces healthcare costs by eliminating prolonged hospital stays and complex perioperative care. Additionally, preserving the colon’s structure and function avoids long-term consequences such as altered bowel habits or ostomy dependence, common with surgical interventions.
The advantages of endoscopic intervention are clear: safety, cost-effectiveness, organ preservation, and convenience for patients.
Lesion Selection
The superiority of endoscopic resection relies on selecting lesions appropriately, specifically those with a low risk of lymph node metastases. This meticulous process should include assessing a lesion’s size, location, morphology, granularity, microvascular and surface pit pattern using a combination of high-definition white light endoscopy, virtual chromoendoscopy and image magnification (when available).
Gross morphologic assessment utilizes the Paris and LST classifications. Combining the Paris classification, lesion granularity and location is both straightforward and revealing. Ulcerated/excavated lesions (0-III) are concerning for deep invasion. Depressed (0-IIc) morphologies are strongly associated with T1 CRC. Nodular lesions (0-Is or IIa + Is) have a higher risk of T1 colorectal cancer (CRC), compared with flat lesions (0-IIa or 0-IIb). Non-granular lesions (0-Is and 0-IIa + Is) have a higher risk of covert cancer. Finally, the rectosigmoid location is associated with an increased risk of T1 CRC (vs. proximal locations).
Endoscopic surface pattern assessment increases one’s diagnostic accuracy. There are three primary endoscopic surface pattern classifications: NBI International Colorectal Endoscopic (NICE), Japanese NBI expert team (JNET), and Kudo pit pattern classifications. Colonic lesions that have a NICE Type 3, JNET 3, or Kudo type Vn pattern should be referred promptly for surgical resection. Lesions with a JNET 2B or Kudo type VI carry a higher risk of superficial T1 CRC but can still be removed endoscopically (see below) in expert centers. All other lesions should undergo endoscopic resection.
Endoscopic Resection Techniques
Endoscopic resection of large colorectal polyps encompasses two primary techniques: EMR and endoscopic submucosal dissection (ESD), each tailored to specific lesion characteristics and operator expertise.
EMR, the technique of choice for the vast majority of lesions, relies on injecting a submucosal cushion to lift the lesion before excision. Recent advances, including enhanced snare designs and underwater EMR, have improved en-bloc resection rates, significantly reducing recurrence and enhancing the efficacy of this technique.
ESD offers unparalleled precision for en-bloc resection of complex lesions, particularly those with fibrosis or high-risk features. Cutting-edge innovations, such as traction devices, have streamlined the procedure, addressing the traditional challenges of ESD. Despite being more time intensive, ESD minimizes recurrence and provides complete histopathological evaluation, critical for the management of malignant or pre-malignant lesions.
For non-lifting polyps, newer techniques such as endoscopic full-thickness resection (eFTR), using tools like the Full-Thickness Resection Device (FTRD), enable resection of up to 2-3 cm of the colonic or rectal wall. This ensures complete removal of any lesion and its underlying tissue, effectively preventing recurrence.
These advancements demonstrate how endoscopy can tackle even the most challenging colorectal polyps, reinforcing its position as the preferred treatment modality.
Perceived Limitations
With ongoing refinement over the last 2 decades, many of the perceived limitations (below) of endoscopic resection have now been overcome.
- Difficult locations/access: Historically lesions at the anorectal junction, ileocecal valve, appendiceal orifice and anastomoses were preferentially sent for surgery. In spite of unique technical challenges at each of these locations, there is now compelling data supporting EMR for these scenarios. We now also have techniques aimed at enabling the resection of lesions with poor access including patient repositioning, distal attachments, variable endoscope diameter/flexibility, traction and overtube devices.
- Recurrence: In the past, recurrence after endoscopic resection of lesions > 20 mm has been reported to be as high as 20%. With our current systematic approach to complete resection, meticulous examination of the post-resection defect for residual polyp tissue, adjunctive techniques to address submucosal fibrosis (hot avulsion, CAST, submucosal release) and thermal ablation to the resection margin (EMR-T), the risk of recurrence for piecemeal resections can be decreased to < 5%. In fact, some groups argue for the en-bloc resection of all large colorectal lesions based on the extremely low (< 1%) recurrence rates and potential for decreased follow-up.
- Post-resection bleeding: Post-resection bleeding is no longer a major limitation of any endoscopic approach because of the combination of improved intra-procedural hemostatic and resection techniques, optimized electrosurgical technology, and enhanced defect closure capabilities and devices (with prophylactic defect closure now supported by randomized control trial level data).
- Perforation: Deep mural injury, once an endoscopists’ worst fear during resection, is no longer a surgical emergency. It can now be predicted, identified (Sydney classification) and successfully managed. In spite of more widespread aggressive resection strategies, the risk of emergency surgery in patients undergoing EMR and even ESD (where the risk of DMI is significantly higher) is extremely low.
Endoscopic resection for large colorectal polyps is effective, available, minimally invasive and organ sparing making it the standard of care for the management of colonic polyps. With ongoing iteration in techniques, more invasive surgical approaches can be avoided in almost all patients with benign and low-risk T1 colorectal cancers.
Dr. Gabr is associate GI division director at the University of Cincinnati, Ohio. Dr. Mosko is based in the division of gastroenterology at St. Michael’s Hospital, Toronto, Ontario, Canada. The authors declare no conflicts of interest.
Blurred Lines: Polyp Needing Surgical versus Endoscopic Excision
BY IRA LEEDS, MD
I am grateful for the invitation to join in discussion with Dr. Gabr and Dr. Mosko on the ever-increasing role of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). However, as a surgeon, I do carry at least mild trepidation entering one of the literary “safe spaces” of my gastroenterology colleagues.
With the increasing evidentiary support of EMR approaches and the increasing experience of those performing ESD, these two techniques are quickly becoming the options of choice. As these practices become ubiquitous, it is important to recognize both their advantages and limitations, compared with available surgical options. The decision to proceed with EMR and ESD is essentially a turning point away from early surgical referral for a complex lesion. In this discussion, I intend to highlight when EMR and ESD have a clear advantage to early surgical referral, why I believe that early surgical referral is still superior to advanced endoscopic techniques in the rectum, and why the approach for right-sided lesions should hinge on careful shared decision-making.
Endoscopic approaches nearly always beat surgical approaches when considering short-term risks. Even in the best surgical series, colorectal surgery typically leads to complications in 10%-15% of patients, 1%-5% being serious. Moreover, transabdominal surgical interventions (ie, colectomy) require considerable recovery involving at least a few days in the inpatient setting and over a month of activity restrictions. Finally, there is a minority of chronically unwell patients who cannot tolerate surgical intervention but may be fortunate enough to have a lesion that with enhanced attention can be endoscopically resectioned. While EMR and ESD also contribute a disproportionate burden of complications to endoscopy practice, overall complication rates are still favorable when compared with surgical resection.
Moreover, the most feared short-term complication of EMR and ESD, perforation, has the added benefit of a “controlled failure” to colectomy. Advanced endoscopic approaches already require a prepared colon, and patients are given strict return instructions. Hence, the yearly handful of postprocedural perforations that I get called upon to assist with typically tolerate a routine surgical exploration, repair or resection, and recover at rates equal to or better than elective colon resections. For these reasons, lesions that can be endoscopically removed within appropriate risk tolerances, can and should be considered for EMR or ESD at time of diagnosis.
There are two clinical scenarios where this consideration for up-front EMR or ESD requires further caution. First, any rectal lesion considered for advanced endoscopic techniques really needs to be done in multidisciplinary conference with a colorectal surgeon. In the modern era of colorectal surgery, surgeons now have numerous approaches to reach the rectum that bridge the gap between traditional endoscopy and transabdominal resection. For many rectal lesions, transanal laparoscopic and robotic approaches offer the opportunity for local excision. The most commonly practiced approach, transanal minimally invasive microsurgery (TAMIS), provides many of the benefits of endoscopy (eg, same-day discharge, no activity restrictions, limited periprocedural physiologic stress, low complication rates) while providing the surgical precision, repair strategies, and specimen orientation of conventional surgery. Anecdotally, the time it takes to do a high-quality TAMIS excision in the rectum can be substantially less than that required for a comparable ESD.
For rectal lesions in particular, specimen quality is paramount for oncologic prognosis. Regardless of any intrinsic favorable histopathology or deft hand of the endoscopist, a TAMIS approach will typically provide for a deeper partial thickness or even full thickness excision. More times each year than I would like, I find myself at a multidisciplinary tumor board discussing an endoscopically removed rectal lesion done in a piecemeal fashion or insufficient deep ESD where appropriate risk stratification is impossible and we end up offering patients a likely overly aggressive proctectomy or a potentially oncologically unsound re-excision. Consideration of EMR/ESD vs TAMIS up front would allow better sorting of which technique is most suited to which lesion and avoid these diagnostic dilemmas that only seem to be more common as EMR and ESD practices proliferate.
For a different set of reasons, an advanced cecal adenoma may also be more suited to upfront surgical considerations. Right colon lesions can be more challenging for surveillance for a host of reasons. Procedurally, right colon lesions are undeniably more difficult. The thin-walled cecum can be unforgiving for repeated polypectomies. Despite it being an uncomfortable subject for colonoscopists, the evidence suggests that getting to the cecum is not consistent or 100% expected. Finally, patients can be unwilling to undergo serial bowel preparation and endoscopic examination. In contrast, a laparoscopic right colectomy avoids these issues while also attributing little additional risk. Laparoscopic right-colon operations have overall complication rates of less than 10% and major complications of less than 1%. Hospital stays for laparoscopic right colectomy are typically 3 days or less. Finally, surgery reduces both the frequency of surveillance, and a shortened colon makes surveillance easier.
Advanced polypectomy techniques broaden our ability to address even difficult lesions under the ideally aligned degree of invasive procedure. However, like any procedure, these techniques have their own advantages and limitations. There will always be a minority of premalignant colon lesions that are best suited to surgery-first approaches to treatment. In my practice, maintaining open lines of communication and regular interaction with my endoscopy colleagues naturally leads to polyps being addressed in their most suitable fashion.
Dr. Leeds is assistant professor of surgery at the Yale School of Medicine and a staff surgeon at the VA Connecticut Healthcare System. He declares no conflicts of interest.