Piecemeal Endoscopic Mucosal Resection Research Articles

356. TUMOUR BURDEN CORRELATES WITH THE RISK OF RECURRENCE AFTER PIECEMEAL ENDOSCOPIC RESECTION OF EARLY-STAGE ADENOCARCINOMA IN BARRETT’S OESOPHAGUS

Abstract Background Endoscopic resection (ER) is curative for Barrett’s oesophagus-related early-stage oesophageal adenocarcinoma (EAC) without high-risk features, such as lymphovascular invasion (LVI), positive margins (R1), and deep submucosal invasion (T1bsm2-3). Piecemeal endoscopic mucosal resection (pEMR), often used for lesions larger than 15mm, prevents assessment of lateral margins and therefore complicates precise risk estimation for residual EAC at the first post-ER endoscopy. Thus, we investigated alternative clinical factors that could potentially be used to assess the risk for residual and recurrent EAC post-ER. Methods We performed a longitudinal cohort study of patients who underwent ER between 2006-2023. Inclusion criteria were: T1a or well/moderately differentiated T1bsm1 EAC; LVI-, and R0 resection. ER was categorised as pEMR (n=106) or en-bloc ER (n=22 en-bloc EMR, n=9 endoscopic submucosal dissection). The primary outcome was residual EAC at first post-ER endoscopy. Secondary outcomes were residual HGD at first post-ER endoscopy, EAC and HGD recurrence at any post-ER endoscopy, and remission of EAC, HGD and intestinal metaplasia (IM) at latest endoscopy. Multivariate logistic regression, receiver operating characteristics, chi-squared, and Kaplan Meier analyses were performed to investigate possible associated risk factors. Results Rates of EAC/HGD recurrence were higher post-pEMR versus en-bloc ER (p=0.019), with residual EAC at first post-ER endoscopy accounting for 34% of post-pEMR recurrence. The percentage of pEMR specimens with EAC (p=0.022) and T1bsm1 staging (p=0.013) were independent risk factors for residual EAC at first post-pEMR endoscopy (Table 1). A 53.5% cut-off of involved pEMR specimens was identified as the optimal threshold for residual EAC prediction (specificity=0.68, sensitivity=0.67). Indeed, residual (p=0.012) and recurrent (p=0.00077) EAC rates were higher when EAC involvement was >53.5%. However, rates of EAC (p=0.13), HGD (p=0.19) and IM (p=0.76) remission were unaffected by high EAC burden. Conclusions High burden of EAC on pEMR specimens correlates with increased risk of residual and recurrent EAC at post-pEMR endoscopy. Post-pEMR site check is recommended prior to endoscopic ablation, particularly in patients where more than 50% of pEMR specimens show EAC and in cases of flat subtle lesions. This will ensure eradication of any residual disease and high success rates for treatment of early EAC using endotherapy.

Can optical evaluation distinguish between t1a and t1b esophageal adenocarcinoma: an international expert inter-observer agreement study.

While piecemeal endoscopic mucosal resection (EMR) for T1a oesophageal adenocarcinoma is acceptable, enbloc-R0 excision is advocated for T1b disease as it may offer a potential cure and mitigate recurrence. Thus, distinguishing between T1a and T1b disease is imperative under current treatment paradigms. We sought to ascertain whether expert Barrett's endoscopists were able to make this distinction based on optical evaluation. Sixty sets of endoscopic images of histologically confirmed high grade dysplasia (HGD), T1a and T1b disease (n=20 for each) were compiled from consecutive patients at a single institution. Each set contained four images, and were standardized to include an overview, a close-up in high-definition white light, a near-focus magnification image, and a narrow-band image. Experts were invited to predict histology for each set. 19 experts from 8 countries (Australia, USA, Italy, Netherlands, Germany, Canada, Belgium, and Portugal) participated. The majority had been practicing for >20 years, with a median annual case volume for Barrett's EMR of 50 (IQR 18-75), and Barrett's ESD of 25 (IQR 10-45). Oesophageal adenocarcinoma (T1a/b) could be distinguished from HGD, with a pooled sensitivity of 89.1% (95% CI:84.7-93.4. When predicting T-stage for T1b adenocarcinoma cases, pooled sensitivity was 43.8% (95% CI:29.9-57.7). Fleiss' kappa was 0.421 (95% CI:0.399-0.442, P<0.001), indicating fair-to-moderate agreement. Expert Barrett's endoscopists can reliably differentiate T1a/T1b oesophageal adenocarcinoma from HGD. Although there is fair-to-moderate agreement for T-staging, T1b disease cannot be reliably distinguished from T1a disease. This may have implications on clinical decision making and selection of endoscopic treatment methods.

Efficacy of cold piecemeal EMR of medium to large adenomas compared with sessile serrated lesions

There is growing evidence for the role of cold piecemeal endoscopic mucosal resection (C-EMR) in the treatment of colorectal lesions ≥10mm. However, it is unclear if it is equally efficacious for all histologic subtypes and sizes. This retrospective study compares the efficacy and safety of C-EMR in the resection of medium (10-19mm) and large (≥20mm) serrated and adenomatous lesions. A retrospective analysis was performed of Paris IIa colonic lesions resected utilising a C-EMR technique over a 3.5 year period at our center. C-EMR was performed for 242 lesions in 151 patients. Lesion size ranged between 10mm to 50mm, with median size of 20mm. Ninety-five polyps were adenomatous, with 147 sessile serrated lesions (SSLs). At six month surveillance colonoscopy, the combined recurrence rate was 6.2%. Adenomas ≥20mm demonstrated a higher rate of recurrence (16.1%) compared to large SSLs (4.1%), medium adenomas (3.0%), and medium SSLs (1.4%). There were no adverse events reported following C-EMR. C-EMR seems to be less effective for the resection of large adenomas when compared to medium adenomas or large SSLs. C-EMR is equally safe for all lesion size and histology.

Impact of Annual Case Volume on Colorectal Endoscopic Submucosal Dissection Outcomes in a Large Prospective Cohort Study.

The adoption of colorectal endoscopic submucosal dissection (ESD) is still limited in the West. A recent randomized trial showed that ESD is more effective and only slightly riskier than piecemeal endoscopic mucosal resection; reproducibility outside expert centers was questioned. We evaluated the results according to the annual case volume in a multicentric prospective cohort. Between September 2019 and September 2022, colorectal ESD was consecutively performed at 13 participating centers classified as low volume (LV), middle volume (MV), and high volume (HV). The main procedural outcomes were assessed. Multivariate and propensity score matching analyses were performed. Three thousand seven hundred seventy ESDs were included. HV centers treated larger and more often colonic lesions than MV and LV centers. En bloc , R0, and curative resection rates were 95.2%, 87.4%, and 83.2%, respectively, and were higher at HV than at MV and LV centers. HV centers also achieved a faster dissection speed. Delayed bleeding and surgery for complications rates were 5.4% and 0.8%, respectively, without significant differences. The perforation rate (overall: 9%) was higher at MV than at LV and HV centers. Lesion characteristics, but not volume center, were independently associated with both R1 resection and perforation. However, after propensity score matching, R0 rates were significantly higher at HV than at LV centers, and perforation rates were significantly higher at MV than at HV centers. Colorectal ESD can be successfully implemented in the West, even in nonexpert centers. However, difficult lesions must still be referred to experts.

Long-term adenoma recurrence and development of colorectal cancer following endoscopic mucosal resection in large non-pedunculated colonic polyps ≥4 cm

ObjectivesData of long-term follow up for large non pedunculated colorectal polyps (LNPCPs) ≥4 cm removed with piecemeal wide field endoscopic mucosal resection (PWF-EMR) are limited. We primarily evaluated the recurrence rates and secondarily the rates of post colonoscopic polypectomy colorectal cancer (PCPCRC) on a long-term basis. MethodsWe retrospectively reviewed a prospectively-stored electronic database of all patients who underwent PWF-EMR for LNPCPs at the Venizeleion General Hospital, between 2009 and 2020. Eligible patients were those with LNPCPs ≥4 cm, deemed completely removed by endoscopic means and followed-up for a minimum of 36 months with at least two surveillance colonoscopies, the first one (SC1) (4–6) months after the initial PWF-EMR procedure and the second one (SC2) after (12–18) months. In 2023, all cases were checked for PCPCRC development. ResultsResidual/early recurrent tissue was detected in 44 (31 %) cases among the 142 (82 males, 60 females) assessed during SC1. Late recurrent tissue was detected in 9 (6.6 %) cases among the 137 surveyed during SC2. Investigation did not reveal any case of PCPCRC . ConclusionsThis historical cohort shows that the PWF-EMR for LNPCPs ≥4 cm is a safe and definitive removal method while it is not associated with the appearance of PCPCRC.

Endoscopic submucosal dissection versus endoscopic mucosal resection for the treatment of rectal lesions involving the dentate line

BackgroundThe ideal treatment of epithelial neoplastic rectal lesions involving the dentate line is a controversial issue. Piecemeal endoscopic mucosal resection (EMR) is the most commonly used resection technique, but it is associated with high recurrence rates. Endoscopic submucosal dissection (ESD) has been shown to be safe and effective for the treatment of rectal lesions, but evidence is lacking concerning its application close to the dentate line. The aim of our study is to compare ESD and EMR for the treatment of epithelial rectal lesions involving the dentate line.MethodsWe identified all cases of endoscopic resections of rectal lesions involving the dentate line performed in two German high-volume centers between 2010 and 2022. Periinterventional and follow-up data were collected and retrospectively analyzed.ResultsWe identified 68 ESDs and 62 EMRs meeting our inclusion criteria. ESD showed a significant advantage in en bloc resection rates (89.7% vs. 9.7%; P = 0.001) and complete resection rates (72.1% vs. 9.7%; P = 0.001). The overall curative resection rate was similar between both groups (ESD: 92.6%, EMR: 83.9%; P = 0.324), whereas in the subgroup of low-risk adenocarcinomas ESD was curative in 100% of the cases vs. 14% in the EMR group (P = 0.002). There was one local recurrence after ESD (1,5%) vs. 16 (25.8%) after EMR (P < 0.0001), and the EMR patients required an average of three further interventions.ConclusionESD is superior to EMR for the treatment of epithelial rectal lesions involving the dentate line and should be considered the treatment of choice.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024.

1: ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2: ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3: ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4: ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5: ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6: ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7: Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8: ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9: ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10: ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11: ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Recurrences of advanced sessile and lateral spreading colorectal adenoma after endoscopic mucosal resection (EMR) thermal ablation versus no adjuvant therapy (RESPECT): a protocol of an international randomized controlled trial

BackgroundNowadays, large benign lateral spreading lesions (LSLs) and sessile polyps in the colorectum are mostly resected by endoscopic mucosal resection (EMR). A major drawback of EMR is the polyp recurrence rate of up to 20%. Snare tip soft coagulation (STSC) is considered an effective technique to reduce recurrence rates. However, clinical trials on STSC have mainly been conducted in expert referral centers. In these studies, polyp recurrence was assessed optically, and additional adjunctive techniques were excluded. In the current trial, we will evaluate the efficacy and safety of STSC in daily practice, by allowing adjunctive techniques during EMR and the use of both optical and histological polyp recurrence to assess recurrences during follow-up.MethodsThe RESPECT study is a multicenter, parallel-group, international single blinded randomized controlled superiority trial performed in the Netherlands and Germany. A total of 306 patients undergoing piecemeal EMR for LSLs or sessile colorectal polyps sized 20–60 mm will be randomized during the procedure after endoscopic complete polyp resection to the intervention or control group. Post-EMR defects allocated to the intervention group will be treated with thermal ablation with STSC of the entire resection margin. Primary outcome will be polyp recurrence by optical and histological confirmation at the first surveillance colonoscopy after 6 months. Secondary outcomes include technical success and complication rates.DiscussionThe RESPECT study will evaluate if STSC is effective in reducing recurrence rates after piecemeal EMR of large colorectal lesions in daily clinical practice performed by expert and non-expert endoscopists. Moreover, endoscopists will be allowed to use adjunctive techniques to remove remaining adenomatous tissue during the procedure. Finally, adenomatous polyp recurrence during follow-up will be defined by histologic identification.Trial registrationClinicalTrials.gov NCT05121805. Registered on 16 November 2021. Start recruitment: 17 March 2022. Planned completion of recruitment: 31 April 2025.

Risk factors of unintentional piecemeal resection in endoscopic mucosal resection for colorectal polyps ≥ 10 mm

This study aimed to investigate the lesion and endoscopist factors associated with unintentional endoscopic piecemeal mucosal resection (uniEPMR) of colorectal lesions ≥ 10 mm. uniEPMR was defined from the medical record as anything other than a preoperatively planned EPMR. Factors leading to uniEPMR were identified by retrospective univariate and multivariate analyses of lesions ≥ 10 mm (adenoma including sessile serrated lesion and carcinoma) that were treated with endoscopic mucosal resection (EMR) at three hospitals. Additionally, a questionnaire survey was conducted to determine the number of cases treated by each endoscopist. A learning curve (LC) was created for each lesion size based on the number of experienced cases and the percentage of uniEPMR. Of 2557 lesions, 327 lesions underwent uniEPMR. The recurrence rate of uniEPMR was 2.8%. Multivariate analysis showed that lesion diameter ≥ 30 mm (odds ratio 11.83, 95% confidence interval 6.80–20.60, p < 0.0001) was the most associated risk factor leading to uniEPMR. In the LC analysis, the proportion of uniEPMR decreased for lesion sizes of 10–19 mm until 160 cases. The proportion of uniEPMR decreased with the number of experienced cases in the 20–29 mm range, while there was no correlation between the number of experienced cases and the proportion of uniEPMR ≥ 30 mm. These results suggest that 160 cases seem to be the minimum number of cases needed to be proficient in en bloc EMR. Additionally, while lesion sizes of 10–29 mm are considered suitable for EMR, lesion sizes ≥ 30 mm are not applicable for en bloc EMR from the perspective of both lesion and endoscopist factors.

Recurrence rate after piecemeal endoscopic mucosal resection of

Introduction There is scarce data focused on recurrence neoplasia rate (RR) after piecemeal endoscopic mucosal resection (pEMR) of 10–19 mm non-pedunculated colorectal lesions (NPL). We aimed to analyze the RR after pEMR of 10–19 mm NPL, identify risk factors for its development and compare it with RR after pEMR of ≥ 20 mm NPL. Methods Retrospective cohort-study including all ≥10 mm NPL resected by pEMR in our center between 2018–2022 with an early repeat colonoscopy (ERC). RR was defined as recurrence neoplasia identified in the ERC EMR scar with virtual chromoendoscopy or histological confirmation. Results A total of 444 NPL were assessed, 124 (27.9%) with 10–19 mm. In the ERC, performed a median of 6 months after pEMR, RR was significantly lower for 10–19 mm NPL compared to ≥ 20 mm NPL (13/124 vs 68/320, p = 0.005). In subgroup analysis, RR after pEMR of 15–19 mm NPL was significantly higher compared to 10–14 mm NPL (13/98 vs 0, p = 0.041) but not significantly different compared to ≥ 20 mm NPL (13/98 vs 68/320, p = 0.073). In multivariable analysis, size of NPL (HR 1.501, 95% CI 1.012–2.227, p = 0.044) was the only independent risk factor identified for RR for 10–19 mm NPL. Conclusion Although the early RR after pEMR of 10–19 mm NPL is significantly lower compared to ≥ 20 mm NPL, it is non-negligible (10.5%) and appears to be the highest among 15–19 mm NPL. The size of the lesion was the only independent risk factor for RR. Our findings should be accounted in the selection of the most appropriate post-polypectomy endoscopic surveillance.

Endoscopic resection of large anastomotic polyps is safe and effective.

Large (≥20mm) adenomatous anastomotic polyps (LAAPs) are uncommon. Data pertaining to their prevalence, characteristics, and the efficacy of endoscopic resection (ER) are absent. A safe and effective strategy for ER would reduce morbidity and healthcare costs. Large nonpedunculated colorectal polyps of ≥20mm (LNPCPs) referred for ER were prospectively studied. Multiple data points were recorded including anastomotic location, polyp morphology, resection modality, complications, and technical success. Over 7 years until November 2022, 2629 lesions were referred. Of these, 10 (0.4%) were LAAPs (median size 35 mm [interquartile range (IQR) 30-40mm]). All LAAPs were removed by piecemeal endoscopic mucosal resection (EMR), most (n=9; 90%) in combination with cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). On comparison of the LAAP group with the conventional LNPCP group, CAST was more commonly used (90% vs. 9%; P<0.001) and deep mural injury (DMI) type II was more frequent (40% vs. 11%, P=0.003); however, significant DMI (III-V) did not occur. At 6 month (IQR 5.25-6 months) surveillance, there was no recurrence in any of the 10 cases. There were no serious adverse events. LAAPs present unique challenges owing to their location overlying an anastomosis. Despite these challenges they can be safely and effectively managed endoscopically without recurrence at endoscopic follow-up.

Endoscopic treatment of colorectal polyps and early colorectal cancer

Background: Colonoscopy offers higher diagnostic sensitivity than other colorectal cancer screening methods and provides the advantage of both diagnostic tissue sampling and polyp removal. Since the majority of colorectal cancers evolve from adenomatous polyps, polyp resection through colonoscopy is widely considered an effective method of preventing colorectal cancer and reducing mortality rates.Current Concepts: Determining colorectal polyp size and shape requires comprehensive endoscopy with enhanced imaging techniques to choose treatment directions and the appropriate colorectal polypectomy method. The selection of the polypectomy method is contingent upon the polyp’s attributes and possible malignancy according to US Multi-Society Task Force on Colorectal Cancer and European gastrointestinal endoscopy guidelines. This article examines eight polypectomy procedures: cold forceps polypectomy, hot biopsy polypectomy, cold snare polypectomy, hot snare polypectomy, endoscopic mucosal resection (EMR), and modified EMR techniques. Each method has unique benefits and is suitable for particular polyp types and sizes. Piecemeal EMR and endoscopic submucosal dissection offer alternatives for larger or challenging lesions that require careful planning and follow-up. After endoscopic resection of early colorectal cancer, further surgery may be necessary depending on the risk of lymph node metastasis as determined by specific histologic findings following Korean and Japanese guidelines.Discussion and Conclusion: The choice of endoscopic resection technique, which depends on factors such as polyp shape, size, and location as well as endoscopist skill, is crucial for ensuring complete polyp removal.

S193 Adoption and Outcomes of Mucosal Defect Margin Snare Tip Soft Coagulation Following Piecemeal Endoscopic Mucosal Resection

S193 Adoption and Outcomes of Mucosal Defect Margin Snare Tip Soft Coagulation Following Piecemeal Endoscopic Mucosal Resection

Piecemeal Resection for Large Colorectal Adenomas Remains Essential in 2022: A Single-Center Experience in a Tertiary French Center.

Colorectal lesions measuring greater than 20 mm are unsuitable for en bloc endoscopic mucosal resection (EMR): piecemeal EMR (PM-EMR) and endoscopic submucosal dissection (ESD) are needed. The European Society of Gastrointestinal Endoscopy (ESGE) recommends ESD only for microinfiltrative lesions, although Japanese teams perform en bloc ESD for all lesions. We report the outcomes obtained in our endoscopy unit for these lesions and assess the hybrid "knife-assisted piecemeal EMR" (KAPM-EMR) technique. The main aim was to assess the short-term outcomes (C1). The secondary objectives were to evaluate the long-term results (C2), adverse event rate and management of recurrence. We retrospectively analyzed data from patients treated by PM-EMR, KAPM-EMR and ESD for a colorectal lesion measuring greater than 20 millimeters using prospective inclusion over four years. Data from 167 patients (median age: 70) with a median follow-up of 15.1 months were analyzed after excluding 95 patients. A total of 131 lesions were removed by PM-EMR, 24 by KAPM-EMR and 12 by ESD; 146/167 (87.4%) patients were considered in remission at C1. Recurrence was treated by endoscopy in 20/21 patients (95%); 86/89 (96.6%) were in remission at C2. A total of 16/167 patients developed adverse events, all of whom except one were endoscopically managed. KAPM-EMR was associated with a higher perforation risk (p=0.037). No differences in postoperative bleeding were found among the three groups (p=0.576). Piecemeal resection remains an effective and safe technique for large colorectal adenomas. KAPM-EMR may be useful but should be applied with caution due to the risk of perforation.

Gastrointestinal: Unusual pathology of an anorectal lesion mimicking a benign laterally spreading tumor.

A 70-year-old woman was referred to our institution for the diagnosis and treatment of an anorectal lesion detected on colonoscopy performed at a previous hospital for hematochezia. Colonoscopy revealed a 32-mm flat elevated lesion in the lower rectum with an anal component extending to the dentate line (Fig. 1a). Chromoendoscopy with indigo carmine spraying demonstrated a papillary surface (Fig. 1b). Magnifying endoscopy with narrowband imaging (NBI) displayed an irregular vessel resembling the intrapapillary capillary loop (IPCL) of the Japan Esophageal Society Classification Type B1 (Fig. 1c). Magnifying endoscopy with 0.05% crystal violet staining revealed the absence of discernible glandular ducts, hindering the evaluation of the pit pattern (Fig. 1d). The endoscopic appearance resembled a large adenoma or condyloma acuminatum; however, the absence of a pit pattern indicated that the lesion was covered with squamous epithelium and not columnar. Moreover, the irregular vessel pattern suggested a neoplastic lesion. Based on these observations, the lesion was diagnosed as a neoplasm originating from the squamous epithelium of the anal canal. Thus, we performed endoscopic submucosal dissection for complete elimination. Histological examination revealed a papillary growing squamous cell carcinoma (SCC) exhibiting low-grade and high-grade atypia and abundant dilated vessels (Fig. 2a). The tumor extended from the anal transitional zone (ATZ) to the rectum and entrapped the rectal crypts (Fig. 2b). Some tumor cells had a clear cytoplasm, indicative of koilocytosis (Fig. 2c), and positive p16 immunohistochemical staining suggested human papillomavirus (HPV) infection (Fig. 2d). The final diagnosis was HPV-associated SCC in situ originating from the ATZ with rectal extension. Anal canal cancer (ACC) is a rare disease that accounts for only 0.3% of all malignancies and is strongly associated with high-risk HPV (HPV-16 and HPV-18). This case was unusual because of the extensive infiltration of the columnar epithelium. Therefore, it might be misidentified as a rectal adenoma. Early ACC shows irregular vessel patterns reminiscent of esophageal SCC on magnified endoscopic NBI, which has been reported to be useful in diagnosing ACC. However, laterally spreading tumor (LST) can exhibit similar irregular capillary vessels. The difference in endoscopic appearance between ACC and LST can be explained by their different epithelial anatomies. ACC develops in the squamous cell epithelium and has no orifice or crypt. In contrast, LST originates from the columnar epithelium and has crypt openings. Condyloma acuminatum has a similar endoscopic appearance but with milder vascular dilatation and caliber changes. In conclusion, HPV-associated anal canal cancer can be suspected in papillary tumors with an irregular esophageal SCC-like vascular pattern and absence of glandular structures. Piecemeal endoscopic mucosal resection can be selected for large adenomas; conversely, en bloc resection is the preferred method for ACC to mitigate the risk of recurrence. To ensure the implementation of appropriate treatment, more attention should be paid to lesions extending along the anal canal to the rectum.

Editorial: Optimizing the success of cold snare polypectomy in colonoscopy practice

Editorial: Optimizing the success of cold snare polypectomy in colonoscopy practice

Commentary.

Local recurrence after piecemeal endoscopic mucosal resection (EMR) is common and it is a major drawback of this technique. Thermal ablation of resection margins after EMR using snare-tip soft coagulation has been shown to decrease the risk of local recurrence in a randomized trial [1]. Hybrid argon plasma coagulation (hAPC) is an alternative ablation technique that can be used to perform margin ablation. Recent studies on hAPC for post-EMR margin ablation showed low rates of local recurrence.

Combining endoscopic mucosal resection with hybrid argon plasma coagulation to reduce local colorectal lesion recurrence: a video tutorial.

Endoscopic mucosal resection (EMR) is a safe, effective, and surgery-sparing technique for removing large colorectal lesions [1]. Although piecemeal EMR is recommended for polyps > 20 mm in size, it remains a suboptimal technique for complete lesion resection, with high rates of residual polyp and recurrence rates reaching 15 % [2]. Hybrid argon plasma coagulation (hAPC) is a novel approach allowing ablation of resection margins and surface after EMR. hAPC combines waterjet injection and argon plasma coagulation (APC) in a single device. On-demand, repeatable saline cushioning without instrument exchange reduces thermal ablative insult to deep tissue structures, allowing for effective destruction of micro-remnants with reduced risk of perforation. High technical success and low recurrence rates (0 %) were shown in a pilot study using EMR in combination with hAPC [3]. A prospective international multicenter study showed that the local recurrence rate was only 2.2 % when using hAPC after EMR [4]. One recent meta-analysis found the local recurrence rate to be 3.3 % after hot EMR and margin ablation at 12-month follow-up [5].

Alligator forceps-assisted piecemeal endoscopic mucosal resection for a large laterally spreading tumor of the papilla.

Alligator forceps-assisted piecemeal endoscopic mucosal resection for a large laterally spreading tumor of the papilla.

Need for adjunctive removal techniques for endoscopic mucosal resection of large non-pedunculated colonic polyps is predictive of recurrence

Abstract Background and study aims Endoscopic mucosal resection (EMR) allows for safe and effective removal of large non-pedunculated colon polyps, but recurrence remains a significant concern. Risk factors for recurrence have previously been reported, however, the significance of these factors have varied and has uncertain applicability with recent advances in EMR techniques. We aimed to evaluate rates and risk factors for recurrence in recent years from a major Canadian referral center. Patients and methods Consecutive patients between April 1, 2017 and March 1, 2019 who underwent piecemeal EMR were retrospectively identified. Patients with non-pedunculated colorectal polyps ≥ 2 cm removed by piecemeal EMR with available follow-up data were included. Results Five hundred and seventeen patients were reviewed, with 265 patients satisfying inclusion criteria. The median age was 67 years (IQR 14); 48 % were female. 15 % had a recurrence on follow-up endoscopy. Adjunctive removal techniques were utilized in 31 % of patients, 95 % of which was hot avulsion. The use of adjunctive removal techniques (OR 2.87, P = 0.004) and male gender (OR 3.31, P = 0.003) was significantly predictive of recurrence on multivariate analysis. Receiver operating curve characteristics demonstrated good performance of these factors in predicting recurrence (area under the curve = 0.70). Conclusions The use of adjunctive removal techniques, particularly hot avulsion and male gender are predictive of recurrence after piecemeal EMR of large non-pedunculated colorectal polyps. Male patients and those who require hot avulsion may be considered high risk for recurrence and warrant closer follow-up.