Polypectomy Site Research Articles

Risk of metachronous colorectal cancer associated with polypectomy during endoscopic diagnosis of colorectal cancer

Background and aimThere are conflicting reports regarding the risk of metachronous colorectal cancer (CRC) subsequent to colonoscopy with polypectomy or biopsy performed concurrently with diagnostic biopsies for CRC. We aimed to establish the 5-year risk of CRC in patients who had synchronous polypectomy or biopsies during the colonoscopy at which CRC was diagnosed.MethodsThis is a single-centre retrospective case–control study of adults who underwent surgical resection for CRC over a 2-year period (January 2016 to December 2017). Colonoscopy details of interest were the location of the CRC, polypectomy and non-CRC biopsy sites. In patients with CRC at index colonoscopy, we sought associations between the occurrence of metachronous CRC and the sites from which endoscopic specimens had been obtained.ResultsOur study population comprised 225 patients with a median (IQR) age of 71 (60–77) years. Polypectomy or biopsy at a non-CRC site had been performed during the index colonoscopy in 108 patients (48%), including 83 (37%) polypectomies outside the surgical resection field. There were 8 (3.6%) metachronous CRCs: 1 (0.4%) at the site of endoscopic mucosal resection for a 15-mm sessile serrated lesion, 3 (1.3%) anastomotic site CRCs and 4 (1.8%) at other sites within the colon. There was no significant difference in the prevalence of metachronous CRC in patients who underwent polypectomy/biopsy at the index colonoscopy compared with those who did not (1.9% vs. 5.1%, p = 0.283).ConclusionThere was no significant increased risk of metachronous CRC subsequent to synchronous polypectomy or biopsy during the colonoscopy at which CRC was diagnosed.

S2179 A Case of Anorectal Junction Melanoma

Introduction: Malignant melanoma of the rectum is an extremely rare disease that is aggressive in nature and often at an advanced stage at the time of diagnosis. We present a case of malignant melanoma of the rectum that was diagnosed on endoscopic polypectomy and staged with endoscopic ultrasound. Case Description/Methods: A 66-year-old, asymptomatic, White female underwent a surveillance colonoscopy. She was noted to have a 20 mm semi-pedunculated rectal polyp (Figure 1), which was piecemeal resected using a hot snare (Figure 1.2). Resection and retrieval were complete. Pathology showed malignant melanoma involving the anal and anorectal junction mucosa (Figure 1.3 and 1.4). The tumor approached the inked resection margin. Immunohistochemical stains were positive for Sox-10 (diffuse and strong) (Figure 1.5), Melan-A (focal), S-100 (focal), and tyrosinase (focal). Stains were negative for pan keratin, CK7, CK20, CDX2, P40, CD56, synaptophysin, CD45, and CEA. EUS performed 3 weeks later showed linear scar just above the dentate line with no residual polyp tissue. Rectal wall at the polypectomy site was thickened without any tumor infiltration and a normal appearing muscular propria. Patient was noted to have 2 hypoechoic lymph nodes 11.4 mm X 8.5 mm and 6.4 mm X 6.0 mm, 8 cm from anal verge (Figure 1.6). Fine needle Aspiration biopsy of the lymph nodes was performed. Pathology from the lymph node showed presence of malignant melanoma. Immunostain positive for MART-1 and SOX-10 but negative for HMB-45. PET/CT did not show any regional or distant metastatic disease. Tumor was staged as Stage III malignant melanoma. Discussion: Malignant melanoma of the distal rectum and anorectal junction is an aggressive and a rare presentation of this disease. It is mostly diagnosed in White women in fifth to sixth decade. Melanocytes are located at the anal transition zone and squamous zone with most anorectal melanomas arising from the dentate line and located at the anal verge or in the anal canal. Due to the hidden location and late onset of symptoms, many of these tumors are advanced by the time of diagnosis. As this case illustrates, tumors are often 20 mm or bigger in size with nodal involvement. Hence the 5 year disease free survival in patients with metastatic disease is only 16%.Figure 1.: 1: Colonoscopy image showing rectal polyp. 2: Colonoscopy image showing post rectal polypectomy site. 3: Pathology showing malignant melanoma involving the anal and anorectal junction mucosa. 4: Pathology showing sheets of melanocytic tumor cells. 5: Pathology showing brown nuclear staining with SOX-10 immunoperoxidase marker. 6: EUS image showing hypoechoic lymph node.

A122 OUTCOMES OF COLD SNARE POLYPECTOMY FOR POLYPS GREATER THAN 20 MM: DATA FROM AN ACADEMIC CENTER

BackgroundCold snare polypectomy (CSP) is widely utilized for resection of small polyps (less than 10mm), due to the technique’s favourable safety profile. However, Hot Snare Endoscopic Mucosal Resection (HSEMR) remains the standard of care for large polyps greater than or equal to 20mm. HSEMR carries an increased risk of complications. These include delayed bleeding, perforation, and post-polypectomy syndrome, along with residual or recurrent adenomatous (RRA).More recently, Cold Snare Endoscopic Mucosal Resection (CSEMR) technique has been used selectively for polyps greater than 20mm. Published studies have demonstrated a significantly lower adverse event rate of complications as compared with HSEMR. RRA utilizing CSP remains a concern, with a recent publication reporting a recurrence of 34.8% on follow-up endoscopy. We present the experience at a single Canadian academic centre with patients undergoing CSEMR for polyps greater than 20mm.AimsTo demonstrate the efficacy and safety of cold snare endoscopic mucosal resection CSEMR of large (greater than or equal to 20mm) polyps at a single Canadian academic centre.MethodsWe retrospectively reviewed colonoscopies performed by endoscopists employing this technique at our centre from January 2020 to August 2021. 15 total cases were identified for patients with polyps greater than or equal to 20 mm, removed by CSEMR technique.ResultsPatient age ranged from 41 to 76, with a median patient age was 66. There were 10 males and 5 females. There were no adverse events intraoperatively. 15/15 (100%) polyps were successfully resected using CSEMR technique. Polyp size ranged from 2 cm to 7 cm, and there was a median polyp size of 3 cm. 14/15 (93%) polyps were proximal to the splenic flexure, with 1/15 (7%) polyp in the rectum. 6/15 (40%) patients received snare tip soft coagulation to the edges of the polypectomy site. Polyp histology included 7 tubular adenomas, 3 tubulovillous adenomas, 4 sessile serrated polyps, and one hyperplastic polyp. Two patients were on aspirin 81 mg daily, and there were zero patients on any other antiplatelets or anticoagulation. 1/15 patient presented with late bleeding requiring emergent colonoscopy. There were no immediate or delayed perforations or other serious adverse events recorded.Approximately 50% of patients have had follow-up colonoscopy within 3–6 months of their initial procedure. Follow-up ranged from 12 to 252 days, with a median time to follow up of 171 days. 3/7 (43%) patients had histologic evidence of recurrence at follow-up colonoscopy, all of which were successfully treated endoscopically.ConclusionsSelective CSEMR is a safe and effective technique, with a low risk of complications. There may be a higher rate of residual polyp at follow-up colonoscopy compared to HSEMR. This data will need further validation with a larger sample size. Funding AgenciesNone

S2223 Rare Colonic Vascular Ectasia Disguised as a Polyp

Introduction: Vascular ectasia in the gastrointestinal (GI) tract is commonly seen as dilated and congested submucosal blood vessels, which appear as characteristic red flat lesions on endoscopy. In the colon, they can be found incidentally and are estimated to be responsible for 2-30% of lower GI bleeds. Polypoid appearing vascular ectasia lesions are exceedingly rare. We report an asymptomatic case of colonic polypoidal vascular ectasia. Case Description/Methods: A 62-year-old asymptomatic man with a history of diabetes mellitus II and hypertension and no family history of GI malignancy presented for his index screening colonoscopy. A 7cm pedunculated polyp was seen in the sigmoid colon (Figure 1a), with mucosa appearing identical to the surrounding mucosa. It was removed with hot snare polypectomy, and the polypectomy site was clipped with two hemoclips. The rest of the colonoscopy was unremarkable. Pathology demonstrated colonic mucosa with mild hyperplastic changes and submucosal vascular ectasia, as evidenced by markedly dilated and congested submucosal vessel that extended the length of the entire polyp with clusters of smaller congested capillaries spreading into the overlying mucosa, as shown in the 20x (Figure 1b) and corresponding high power 400x (Figure 1c) histopathological images. Pathology was negative for dysplasia. Discussion: Polypoid appearing colonic vascular ectasia lesions are infrequent, and literature review shows only 15 lesions matching the description in our case. In addition, these lesions are typically located in the cecum or ascending colon, accounting for 54-81.9% of colonic vascular ectasia. Classically, angiodysplasia of the colon is associated with aortic stenosis, chronic renal failure, and in patients with Von Willebrand disease. In our patient, the patient was asymptomatic, and the lesion was incidentally identified during a screening colonoscopy. The lesion was a large pedunculated polyp located in the sigmoid colon, unlike most colonic vascular ectasias that appear in the right/proximal colon. Since the lesion is benign and not an adenoma of the colon, the colon cancer surveillance interval was determined to be 10 years. This report is pertinent for endoscopists who may encounter abnormal polypoid masses on colonoscopy. Keeping vascular ectasia on the differential diagnosis will aid in both intra-procedure decision-making and post-procedure follow-up.Figure 1.: A. CT Chest with Pneumomediastinum B. Upper Endoscopy With Erythematous Posterior Oropharynx and an Extrinsic, Longitudinal Bulge in the Proximal Esophagus C. Intraoperative Photograph During Thoracotomy.

S212 Comparing Polyp Detection Rate Between Water Exchange and Air Insufflation by a Computer-aided Detection Algorithm: An Analysis of Withdrawal Phase Videos from a Randomized Controlled Trial

Introduction: Water exchange (WE) improves polyp (PDR) and adenoma detection rate (ADR) compared with air insufflation [GIE 2021;93:1411], but still misses polyps due to human limitations [JCG 2021, in press]. A computer-aided detection (CADe) algorithm can overcome human omissions, but is limited by false positives (FPs) [Lancet Gastroenterol & Hepatol 2019;4:71], which might be reduced by salvage-cleaning effect provided by insertion WE [Tzu-Chi Med J 2021;33:108]. We hypothesized that the strengths of CADe and WE can complement the weaknesses of each other. Their combination can enhance PDR and ADR and reduce false positive rate (FPR). Methods: We used a locally developed convolutional neural network with YOLOv4 to build a CADe model. Images of polyps (n=15961) were divided in 80% and 20% for training and testing. Prior to real-time application, we validated the model in detecting polyps, using edited and coded withdrawal phase videos of the right colon from a RCT comparing right colon adenoma detection between WE and air insufflation. The polyps detected by the CADe were confirmed by the consensus of 2 blinded reviewers (experienced endoscopists). We also developed a computer-aided diagnosis (CADx) model based on YOLOv4 to characterize the detected polyps as adenomas or not. The primary and secondary outcomes were PDR and the FPR, respectively. Results: A total of 245 coded videos of colonoscopies inserted with WE (n=123) or air insufflation (n=122) were analyzed. CADe achieved significantly higher PDR in the WE group (61.8%) than in the air insufflation group (40.2%), P=0.0009. CADe also had significantly higher additional PDR in the WE group (30.1% vs 12.3%, P=0.001). The CADx assessed ADR was significantly higher in the WE group than that in the air insufflation group (46.3% vs 30.3%, P=0.018), after the detected polyps were characterized by the CADx. (Table a) The mean numbers of FPs related to feces [1.78 (1.67) vs 2.09 (2.09), P=0.007] and bubbles [0.53 (0.89) vs 1.25 (2.45), P=0.001] were significantly lower in the WE group than in the air insufflation group. (Table b). Conclusion: The data confirmed the hypothesis that the strengths of CADe and WE complemented the weaknesses of each other, enhanced PDR and ADR and reduced FPR. The locally developed CADe and CADx are validated for polyp detection and adenoma assignment for real-time application. Furthermore, WE provides an optimal platform for the computer-assisted algorithms.Table 1.: ADR, adenoma detection rate; All the percentages calculated according to respective total number of patients for each group; PDR, polyp detection rate; Total numbers of polyps were based on those found by the performing endoscopist plus those detected by the CADe; Proportion of additional polyps found by CADe equals numbers of additional polyp (adenomas) found by CADe divided by total numbers of polyps (adenomas). Others: ileocecal valve, cecum, polypectomy site, suction marks and drug pills. † Mann-Whitney test; ††Fisher exact test.

S3686 A Rare Case of Duodenal Neuroendocrine Tumor

Introduction: Neuroendocrine tumors of the duodenum (D-NET) are rarely seen constituting less than 2-3% of gastrointestinal tumors. With NET on rising, it is important to recognize this rare tumor and treat it with early surgical or endoscopic resection. Case Description/Methods: A 52-year-old white male was seen in the office for new onset of dysphagia worse with solid food for few months. He had a history of squamous cell carcinoma of the tongue and had undergone surgical resection with concurrent chemotherapy with cisplatin. His examination and laboratory findings were unremarkable. On endoscopic examination, the patient was found to have a 5 mm size nodule in the second part of the duodenum which was removed with a cold biopsy (Figure A&B). The histopathologic findings were consistent with a well-differentiated neuroendocrine tumor (NET) (figure C&D). The tumor cells were strongly positive for synaptophysin (figure-D), CD56, chromogranin and showed < 1% of Ki-67 labeling index supporting the diagnosis of NET. A PET/CT- GA-68 Dotatate scan confirmed no residual tumor but an increased uptake in the lymph nodes above and below the diaphragm was noted (figure E). These lymphadenopathies are likely falsely positive given the symmetric uptake with awaiting biopsy on follow up. Three months later a repeat endoscopy with biopsy of previous polypectomy site did not show any evidence of remnant NET. Oncology was consulted with suspected disseminated NET and is awaiting further investigation. Discussion: NET is a type of epithelial tumor with predominant neuroendocrine differentiation arising from various organs of the body. The majority of these cases arise from the gastrointestinal tracts followed by lungs, pancreas, ovaries, and head & neck region. Although the GI tract is the most common site of occurrence the NET-D are very rarely seen, constituting less than 3% of GI NET. The overall rate of the NET is on rising with an annual rate of 6.3%. This rise to some extent can be attributed to increased diagnostic imaging utilization. D-NETs produce symptoms based on their location resulting in abdominal pain, intestinal obstruction, jaundice, or rarely pancreatitis. By the virtue of their hormonal production, they can lead to flushing, diarrhea, skin rashes, nausea, or peptic ulcer disease. It is important to recognize these rare tumors and treat them either with surgical or endoscopic resection.Figure 1:: Figure A& B: Esophagogastroduodenoscopy (EGD) – A 5 mm size nodule seen in the second part of the duodenum with normal covering mucosa removed with cold biopsy. Figure C: Duodenal nodule on biopsy (H & E stain @ 4X) - The nested appearance of monomorphic population of tumor cells without nucleoli, necrosis or brisk mitotic activity consistent with neuroendocrine tumor. Figure D: Duodenal nodule on biopsy (4X)- Synaptophysin Immunohistochemical Stain positive consistent with neuroendocrine tumor. Figure E: PET/CT- GA-68 Dotatate: No duodenal uptake noted. Multiple radiotracer acid lymph nodes above and below the diaphragm with prominent on the axilla and bilateral iliac chain & inguinal region.

A Pilot Randomized Trial of Polypectomy Techniques for 4 to 6 mm Colonic Polyps.

There is variation in polypectomy techniques for resection of small polyps. Aim was to compare techniques for 4 to 6 mm polyps for recurrent adenoma, efficiency, and adverse events and to establish methodological factors for definitive trial. The study was a randomized controlled trial. Outpatients with ≥1, 4 to 6 mm polyps were randomized to cold forceps (CF), cold snare (CS), and hot snare (HS). Polypectomy site was marked with SPOT to assess for recurrence at the original polypectomy site during surveillance colonoscopy. To assess feasibility of a definitive trial we measured (1) rates of patient refusal, participation, ineligibility; (2) retention; (3) recurrent neoplasia; and (4) sample size for a definitive trial. Three hundred fifty-three patients were randomized to 1 of the 3 polypectomy techniques, of whom 260 (73.6%) completed the initial colonoscopy (mean age 57 y, 50.4% women), with 91, 87, and 82 patients randomized to CF, CS, and HS polypectomy, respectively. Mean time for polyp resection for CF, CS, and HS were 198.8, 58.5, and 96.8 seconds, respectively, with CS and HS requiring less time than CF (P<0.001). One hundred sixty-four (63.1%) completed surveillance colonoscopy. Polyp recurrences were 9 (14.5%) with CF, 5 (9.6%) with CS, and 0 (0%) with HS. Although the recurrence relative risks with CF and CS polypectomy were 1.84 and 1.65 as compared with HS, respectively, neither was statistically significant. CS and HS polypectomy require less time than CF. HS polypectomy may have a lower risk for recurrent neoplasia. High attrition rate is a challenge in conducting randomized controlled trial with polyp recurrence as endpoint.

Endoscopic characteristics influencing postpolypectomy bleeding in 1147 consecutive pedunculated colonic polyps: a multicenter retrospective study

Postpolypectomy bleeding is the most common adverse event with pedunculated polyps. We clarified the endoscopic characteristics influencing postpolypectomy bleeding for pedunculated colonic polyps. We reviewed clinical data for 1147 pedunculated colonic polyps removed by polypectomy in 5 Japanese institutions. Pedunculated polyps were defined as polyps with a stalk length≥5mm. Analyzed clinical data were age, sex, polyp location/size, stalk length/width, prophylactic clipping or endoloop before polypectomy, injecting the stalk, closing the polypectomy site, antithrombotic agent use, and endoscopist experience. Postpolypectomy bleeding was classified as immediate bleeding or delayed bleeding. Immediate and delayed bleeding was observed in 8.5% (97/1147) and 2% (23/1147) of polypectomies, respectively. Comparing immediate bleeding with nonbleeding, multivariate analysis showed that stalk width≥6mm (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1-3.4) was a significant risk factor for immediate bleeding. For polyp size≥15mm, prophylactic endoloop use (OR, .17; 95% CI, .04-.72) was a significant inhibiting factor. Comparing delayed bleeding with nonbleeding, multivariate analysis showed that prophylactic clipping before polypectomy (OR, 4.2; 95% CI, 1.3-13) and injecting the stalk (OR, 4.0; 95% CI, 1.4-12) were significant risk factors for delayed bleeding. The increased risk for delayed bleeding with injecting the stalk and prophylactic clipping before polypectomy suggests that simple resection with coagulation mode is a suitable strategy in endoscopic resection of pedunculated polyps. Moreover, prophylactic endoloop use was highly likely to inhibit immediate bleeding with polyp size≥15mm.

Local excision after polypectomy for rectal polyp cancer: when is it worthwhile?

The optimal management of a polyp cancer that has been removed endoscopically is unclear. Further local excision is often advocated to remove the polyp stalk or scar or to ensure clear margins, but the benefit of this is unclear. The aim of this paper is to determine whether the indications for further local excision can be better defined. Data were collected from two institutions (in UK and Denmark) which maintain prospective databases to collect information on all patients undergoing transanal endoscopic microsurgery (TEM). The study group was all patients who had a TEM after macroscopically complete polypectomy for rectal cancer. Data covering an 11-year period were analysed. Sixty three patients had TEM with no residual cancer after macroscopically complete polypectomy. Residual adenoma was found in 23 (37%). A postpolypectomy endoscopy had not detected the residual adenoma in three. Malignant local recurrence occurred in five patients (8%) and distant metastases in another two (3%). Recurrence occurred in 4/23 (17%) when there was residual adenoma in the TEM specimen and in 3/40 (7.5%) where there was scar only, although this did not reach significance. In two instances recurrence was around 10years after TEM. Those with residual adenoma at TEM tended to have poorer survival. Further local excision often reveals no residual cancer despite microscopically involved polypectomy margins. Careful endoscopy is required to assess the polypectomy site as residual tumour can be missed. In the absence of residual adenoma, TEM does not appear to be of benefit, although a small risk of recurrence exists.

S1838 Cutting into Colorectal Cancer Prevention: Development of Lymph Node Metastasis Despite Clear Margins

INTRODUCTION: Colorectal cancer (CRC) is the 2nd leading cause of cancer related death within the US despite progressively declining mortality. Advancements in screening guidelines and colonoscopy techniques led to higher adenoma detection rate and increased malignant polyp resection. Although complete resection of malignant polyps with clear margins prevents recurrence, patients are not guaranteed to be CRC risk free. Cancer may be found in the polypectomy site or lymph nodes (LNs). Here we present a case of a polypectomy with clear margins in the sigmoid colon and later findings of metastatic disease to the LNs. CASE DESCRIPTION/METHODS: A 45 y.o. male with a PMH of HTN presented to the outpatient gastroenterologist (GI) office with rectal bleeding for one month. He reported multiple bright red formed stools. FHx was relevant only for his father with h/o benign colon polyps. Colonoscopy 3 weeks later revealed a 50 mm pedunculated polyp in the sigmoid colon. Hot snare excisional polypectomy was performed and the area was tattooed. Histopathology revealed an intact well-differentiated adenocarcinoma invading into the stalk of the tubulovillous adenoma. Stalk margin was negative for invasive carcinoma by 3 mm and staged PT1,pNX with no lymphovascular invasion. Extra vigilance by the patient led to a colorectal surgery follow up. After evaluation, sigmoid colon resection with LN dissection was done. Although no residual adenocarcinoma was identified, 1 of 13 LNs dissected was positive of metastatic adenocarcinoma. The patient was discharged with a 3 month follow up with GI. He underwent chemoradiation and a repeat PET scan at 1 year which was negative for residual disease. Repeat colonoscopy at 1 and 3 years was negative for recurrence. DISCUSSION: Colonoscopy remains the gold standard for detecting and treating polyps. Several studies support demonstrating clear margins to show entire adenoma removal on histopathological examination. Resections >1 mm of free margins show 0–2% recurrence while <1 mm demonstrate 21–33%. Ideally, samples should have >2 mm of free margins but recurrence chances are not 0%. Therefore, individual decisions should be made for discussing possible LN metastasis which inevitably cause recurrence despite complete polyp resection.Close surveillance with oncology and colorectal surgery should be considered in large malignant polyps.Figure 1.: 50mm rectosigmoid polyp with stalk.Figure 2.: Polypectomy with 3mm cancer free margin.Figure 3.: Lymph node with metastatic adenocarcinoma.

S3458 A Tale of Two Dieulafoy’s: Massive GI Hemorrhage from Synchronous Dieulafoy Lesions

INTRODUCTION: Dieulafoy lesions (DL) are an elusive source of gastrointestinal hemorrhage accounting for 5% of all cases. They consist of large aberrant submucosal arterioles that erode through overlying epithelium. Patients present with hematemesis, melenic stools, and/or hemodynamic instability. Bleeding is from a single lesion in the stomach (64%), small intestine (20%), colon (10%), or esophagus (2%). Diagnosis is difficult in the absence of overt bleeding and repeat endoscopy is often required. Management includes epinephrine injection, thermal ablation, hemoclips, or resection. Unfortunately, recurrence can be seen in 5-10% of cases. We report an exceedingly rare case of two synchronous DL actively bleeding during one hospitalization. CASE DESCRIPTION/METHODS: A 61 year old male with ESRD, CAD status-post bypass grafting, atrial fibrillation, and heart failure status-post mitral valve replacement presented with four weeks of melena. Index endoscopy demonstrated duodenal bulb and cecal angioectasias that were ablated with snare polypectomy of four polyps. Bleeding persisted so capsule endoscopy was pursued showing fresh blood in the jejunum and distal ileum. Upper double balloon-assisted enterography (DBE) showed an actively bleeding DL in the mid-distal jejunum that was treated with APC, hemoclips and marked with India Ink. Melena and transfusion-dependent anemia persisted and repeat upper DBE showed oozing from prior DL ablation, thus retreated with APC. Bleeding continued but IR angiogram was unrevealing, so resection was pursued. Unfortunately, despite resection, video capsule, and two colonoscopies with hemoclip placement at polypectomy sites, bleeding continued. A lower DBE revealed an actively bleeding DL 50cm proximal to the ileocecal valve that was treated with APC and hemoclips. Hemostasis was achieved and the patient was discharged. DISCUSSION: Despite endoscopy and small bowel series, the source is not found in up to 5% of overt GI hemorrhages. While DL account for only 5% of GI bleeding cases, they are important due to their propensity to cause significant hemorrhage. DL are typically solitary; only two cases of synchronous DL have been reported in literature, and were isolated to the stomach or stomach and small bowel. This is an unusual case of persistent GI bleeding caused by two active small bowel DL (distal jejunum and ileum) which were synchronously bleeding during one hospital admission. As far as we know, this is the only reported case of two actively bleeding DL in the small bowel.Figure 1.: Initially identified DL in mid-distal jejunum treated with APC & hemoclips.Figure 2.: Synchronous DL 50cm from ICV.

Hot snare polypectomy versus endoscopic mucosal resection for small colorectal polyps: a randomized controlled trial.

This study was performed to compare endoscopic mucosal resection (EMR) with hot snare polypectomy (HSP) in terms of the complete resection rate and the incidence of adverse events for resecting small (5-10mm) colorectal polyps. Small colorectal polyps (5-10mm) with neoplastic features were randomly allocated to either the HSP or EMR group. A submucosal injection was performed prior to hot snaring in the EMR group only. Complete resection was defined as the absence of neoplastic tissue from two additional biopsies of the polypectomy site. R0 resection was defined as the absence of neoplastic tissue at the margin of the resected specimen. A total of 362 colon polyps from 272 patients were included, and 167 polyps in the HSP group and 155 polyps in the EMR group were analyzed. Between the polypectomy techniques, there was no significant difference in the complete resection rates, which were 96.4% (161/167) in the HSP group and 95.5% (148/155) in the EMR group (P = 0.67). The R0 resection rate in the HSP and EMR groups was significantly different, with 49.7% (83/167) and 74.8% (116/155), respectively (P < 0.001). There was no significant difference in the incidence of adverse events between the two groups. The complete resection rates for small (5-10mm) polyps were not different between HSP and EMR. ClincialTrials.gov number NCT02239536.

Mo1631 A PILOT RANDOMIZED TRIAL OF POLYPECTOMY TECHNIQUES FOR 4-6 MM COLONIC POLYPS

There is wide variation in use of polypectomy techniques among endoscopists for resection of 4-6mm polyps. We evaluated the various polypectomy techniques in terms of risk of recurrent adenoma, efficiency and adverse events. The study was a randomized controlled trial, conducted at three endoscopy units at a single institution. Outpatients between the ages of 18-75 years with one or more 4-6 mm polyps were randomized to one of the three polypectomy techniques: cold forceps (CF), cold snare (CS) and hot snare (HS). Patients on long term anti-coagulation and history for inflammatory bowel disease were excluded. Polyp size, location and morphology were recorded as well as polypectomy duration in seconds (s). Each study polypectomy site was tattooed. Adequacy of polypectomy was determined by visual absence of recurrent adenoma tissue on surveillance exam. A total of 353 patients were randomized to one of the three polypectomy techniques. Ninety three patients (26.4%) were excluded post randomization (Figure 1); 260 completed the initial colonoscopy, mean age 57 +/- 6.6 years, 50.4% women). Ninety-one, 87 and 82 patients were randomized to CF, CS and HS polypectomy, respectively (Figure 1). A total of 316 study polyps were identified. Mean (SD) time for polyp resection for CF, CS, and HS were 198.8 s (SD 159.5), 58.5 s (SD 79.6), and 96.8 s (SD 54.6), respectively. CS and HS required less time than CF (P <0.001). From the 260 participants randomized, 96 (36.9%) did not complete the surveillance colonoscopy. Among those who completed surveillance, the number of definite recurrences was 9 with CF, 7 with CS and 1 with HS. The recurrence rate with CF and CS polypectomy was 2.07 (95% CI 0.93-8.54; P=0.32) and 1.69 (95% CI 0.40-9.00; P=0.48) times higher than with HS, respectively, however, neither result was statistically significant. From 260 procedures, there were 6 complications (2.3%): 4 with HS (2 post cautery syndrome, 2 delayed bleeding), 1 with CS (immediate bleeding) and one with CF (immediate bleeding). Three required hospitalization, 3 underwent repeat colonoscopy, 2 had clip placement, 1 had bipolar cautery and 1 required blood transfusion. For polypectomy of 4-6 mm polyps, CS and HS polypectomy require less time than CF. HS polypectomy may have a lower risk for recurrent neoplasia at the polypectomy site, but a larger trial with more complete follow up (i.e. surveillance colonoscopy) is required. High attrition rate is a significant challenge in conducting randomized controlled trials with polyp recurrence as an endpoint.

Recurrence with malignancy after endoscopic resection of large colon polyps with high-grade dysplasia: incidence and risk factors.

In the West, piecemeal endoscopic resection remains the primary treatment for large colon polyps (LCP), as most recurrences are believed to be benign and resectable with follow-up endoscopy. However, invasive malignancy at the site of prior piecemeal endoscopic mucosal resection has been reported in the Asian literature. This study aims to identify the incidence of and the risk factors for local recurrence with malignancy after endoscopic resection of LCP with high-grade dysplasia (HGD). In this retrospective cohort study, we identified patients undergoing complete endoscopic resection of LCPs (≥ 20mm) with HGD at the Cleveland Clinic between January 2000 and December 2016. Demographic, endoscopic, and pathologic data were collected. All subsequent endoscopic and pathology reports were reviewed to identify recurrence. The cumulative incidence of malignancy at the polypectomy site was determined and univariate analysis was performed to assess risk factors. A total of 254 LCPs with HGD were resected in 229 patients. Mean polyp size was 29.2mm. There were 138 lesions resected in piecemeal fashion and 116 en-bloc. After a median follow-up of 28.7months for the entire cohort, local recurrence with malignancy was diagnosed in six cases. Median time to malignancy diagnosis was 28.5months. All malignant cases occurred after piecemeal resection and none after en-bloc resection (HR 11.4; 95% CI 0.48-273). Malignancy after endoscopic resection of LCPs with HGD is uncommon and may be associated with piecemeal resection. When possible, en-bloc resection should be the goal for the management of LCPs.

A case report of iatrogenic gas gangrene post colonoscopy successfully treated with conservative management- is surgery always necessary?

BackgroundColonoscopy is a routine procedure in diagnosis and treatment of colonic disease. While generally regarded as a safe procedure, potentially fatal complications can occur. Gas gangrene is one such complication, with very high mortality. There are few cases of gas gangrene occurring after colonoscopy, making it one of the rarer complications of this procedure. There have been no previously reported cases of a patient surviving such an infection and the optimal treatment strategy is contentious. This report describes a case of intramural gas gangrene of the colon, treated conservatively with antibiotic therapy in which the patient survived with full recovery.Case presentationA 71-year-old, previously healthy male presented 6 h post apparently uncomplicated colonoscopic polypectomy with rigors, nausea, vomiting and right upper quadrant pain. At presentation he was febrile at 40.1 °C but hemodynamically stable. Abdominal computed tomography revealed substantial colonic thickening and several focal intramural gas bubbles (pneumatosis intestinalis) surrounding the polypectomy site. Within 24 h post procedure he became hypotensive and was admitted to ICU in frank septic shock requiring inotropes, and with demonstrable septic myocardial depression. Bloods showed multi-organ derangement with leukocytosis, lactic acidosis, haemolytic anaemia and hyperbilirubinemia. A diagnosis of presumed Clostridial gas gangrene was made, and treatment was initiated with benzylpenicillin, clindamycin, metronidazole and vancomycin. After 4 days in ICU he was stepped down, and discharged after a further 10 days with no surgical or endoscopic interventions. At three-month review he reported being back to full health.ConclusionsThis case demonstrates that gas gangrene infection is a possible complication of colonoscopic polypectomy. This is a cause of rapid deterioration in post-colonoscopy patients and has been misdiagnosed as colonic perforation in previously reported cases of retroperitoneal gas gangrene. Such misdiagnosis delays antibiotic therapy, which likely plays a role in the high mortality of this condition. Early diagnosis and initiation of antibiotic therapy with benzylpenicillin and clindamycin as seen in this case is essential for patient survival. While surgery is typically performed, non-operative management of pneumatosis intestinalis, and potentially gas gangrene is becoming more common and was utilized effectively in this patient.

Rates of Incomplete Resection of 1- to 20-mm Colorectal Polyps: A Systematic Review and Meta-Analysis

Incomplete resection of neoplastic colorectal polyps can result in postcolonoscopy colorectal cancer. We performed a systematic review and meta-analysis to determine the incomplete resection rate (IRR) of colorectal polyps and associated factors. We searched MEDLINE, EMBASE, EBM Reviews, and CINAHL to identify full-text articles that reported IRRs of polyps 1 to 20 mm, published until March 2019. Exclusion criteria were studies of inflammatory bowel disease cohorts, referrals for difficult polypectomy, polyp sizes larger than 20 mm, and endoscopic submucosal resection and/or dissection as polypectomy approaches. IRRs were calculated based on findings from biopsies taken at polypectomy sites or assessments of margins of resected polyps. The primary outcome was IRR for snare removal of polyps 1 to 20 mm. Secondary outcomes included IRR for polyps 1 to 10 mm and 10 to 20 mm, IRR for hot and cold snare removal of polyps 1 to 10 mm and 10 to 20 mm, IRR of snare removal with or without submucosal injection, and IRR for forceps and cold snare removal of polyps 1 to 5 mm. We identified 6148 reports and used 32 studies, with a total of 9282 polyps, in our quantitative analysis. The IRR for snare removal of polyps 1 to 20 mm was 13.8% (95% confidence interval [CI] 10.3-17.3; 13 studies, 5128 polypectomies). IRRs were 15.9% for snare removal of polyps 1 to 10 mm (95% CI 9.6-22.1; 9 studies, 2531 polypectomies) and 20.8% for snare removal of polyps 10 to 20 mm (95% CI 12.9-28.8; 6 studies, 412 polypectomies). The IRR for hot snare removal of polyps 1 to 10 mm was 14.2% (95% CI 5.2-23.2) vs 17.3% for cold snare polypectomy (95% CI 14.3‒20.3). The IRR for forceps removal of polyps 1 to 5 mm was 9.9% (95% CI 7.1-13.0) vs 4.4% for snare polypectomy (95% CI 2.9-6.1). In a systematic review and meta-analysis, we found that colorectal polyps 1 to 20 mm are frequently incompletely resected, and that risk increases for polyps 10 mm or larger. There is no difference in IRRs of cold vs hot snares for polyps 1 to 10 mm. Snare polypectomy should be used over forceps for polyps 1 to 5 mm.

Efficacy and safety of three different endoscopic methods in treatment of 6–20 mm colorectal polyps

Objective: Endoscopic resection of colorectal polyps is widely established as the optimal method to manage precancerous lesions. But the optimal technique for removal of the polyps is uncertain. The aim of this study was to compare the efficacy and safety of three methods for the management of 6–20mm colorectal polyps.Methods: A prospective, randomised controlled trial was conducted at the 900TH Hospital of Joint Logistics Support Force in Fujian, China. Endoscopically diagnosed colorectal polyps, 6–20 mm in size, were randomly assigned to the cold snare polypectomy (CSP), cold snare endoscopic mucosal resection (CS-EMR) or endoscopic mucosal resection (EMR) group. After polypectomy, additional 3–5 forceps biopsies by leading narrow-band imaging (NBI) were performed at the base and margins of polypectomy sites to assess the presence of residual polyp tissue and all samples were sent for histopathological analysis to assess completeness of resection. Polypectomy timing, tissue retrieval and complications were recorded at the time of the procedure.Results: A total of 781 polyps in 404 patients were assessed and randomly assigned to each group. Of these, 763 polyps were finally analyzed based on the pathology results. The complete resection rates with CSP, CS-EMR and EMR were 81.6%, 94.1% and 95.5%, respectively (p < .001). The intraprocedural bleeding rate, immediately after polypectomy, was significantly higher in the CSP group than in the CS-EMR and EMR group (9.4% vs. 4.4% vs. 1.9%; p < .001). However,delayed bleeding was higher in the EMR group than in the CSP and CS-EMR group (2.6% vs. 1.2% vs. 0.8%, respectively; p = .215). In the multivariate analysis showed that the operation method, lesion size, morphology and the number of resection were independent risk factors for complete resection rate (CRR) (p < .05), but the location and pathological classification of polyps had no significant influence on CRR.Conclusions: CS-EMR is safe and effective in the treatment of 6–20 mm colorectal polyps. Especially for 6–15 mm non-pedunculated polyps, CS-EMR has a high histological complete resection rate comparable to EMR, and retains the low risk of delayed complications after polypectomy with cold snare. CS-EMR is expected to become a more valuable new cold-cutting technique after cold snare polypectomy.

Efficacy and safety of cap-assisted endoscopic mucosal resection of ileocecal valve polyps.

Background and study aims Standard endoscopic mucosal resection (EMR) of ileocecal valve (ICV) polyps is challenging. Cap-assisted endoscopic mucosal resection (C-EMR) can be performed when polyps are not easily amenable to standard EMR. Current literature is limited regarding its efficacy and safety for ICV polyps. The objectives of this study were to assess the efficacy and safety of C-EMR for ICV polyps. Patients and methods A retrospective review was conducted from September 2008 to November 2018 at a tertiary care center. Patients included in the study underwent C-EMR for ICV polyps by a single gastroenterologist (LHJ). Polyps were successfully eradicated if they were removed en-bloc as confirmed by pathology, or had a negative biopsy on follow-up colonoscopy. Outcomes of the procedures were evaluated, including complete adenoma clearance and adverse events. Results Twenty-one ICV polyps were removed with C-EMR. Median polyp size was 15 mm (range, 5–45). The rate of complete adenoma clearance was 100 %. Procedure-related complications occurred in five patients (24 %): delayed GI bleeding (4.8 %) and deep mucosal resection/visible vessel (14.3 %). Three patients had subsequent surveillance colonoscopies at 8, 56, and 67 months, respectively. The third patient was found to have a 6-mm flat polyp at the edge of the previous polypectomy site. This was treated with C-EMR and repeat colonoscopy 6 months later did not show residual. Conclusion C-EMR is highly effective in treating ICV polyps with a low complication rate. It is our suggested method in approaching ICV polyps that are difficult to remove via standard freehand snare EMR technique.

Dye-based chromoendoscopy following polypectomy reduces incomplete polyp resection

Background and study aims The completeness of a polyp resection is an important determinant of quality in colonoscopy, and may reduce incidence of interval cancers. Incomplete resection rates (IRR) vary widely and range from 6.5 % to 22.7 %. Residual disease is more likely with larger polyps, for sessile serrated adenomas, and with more proximal lesions. Chromoendoscopy is increasingly employed in lesion detection. The aims of this study were to assess local IRR, and to determine whether chromoendoscopy could correctly identify residual disease post polypectomy. Patients and methods This was a prospective study examining post polypectomy sites. Chromoendoscopy (0.13 % indigo carmine) was applied to resection bases to identify residual disease. Targeted base biopsies were taken from identified residual disease (positive group) or random base biopsies were taken when a clear base was visualised (negative group). Overall rates of incomplete resection were documented. Reported rates post chromoendoscopy and actual histological rates were documented and compared. Results A total of 102 polyps were identified for inclusion, of which 15 % (n = 16) were excluded. Resection quality was evaluated in 86 polyps of 61 patients (female n = 33 54 %; mean Age 62.3 years). Polyps were mainly removed by cold snare (n = 71, 82.5 %). Most polyps (n = 58, 67 %) measured between 5 to 10 mm. Polyps were largely located in the right colon (n = 57, 66 %). Overall histological residual disease occurred in 17 /86 (19.6 %). Chromoendoscopy correctly identified residual disease in 13 of 17 bases (76.5 %). Only four of /86 (4.6 %) of polyp bases were missclassified post-chromoendoscopy (odds ratio 0.284 (95 % CI 0.0857–0.9409), P = 0.03). Conclusion Indigo carmine chromoendoscopy improves early detection of residual disease post polypectomy, reducing incomplete resection rates.

Efficacy and Safety of Endoscopic Resection of Sessile Serrated Polyps 10 mm or Larger: A Systematic Review and Meta-Analysis

The best method for endoscopic resection of sessile serrated polyps (SSP) 10 mm or larger is unclear; studies report variable outcomes in comparison to conventional adenomas. We performed a systematic review and meta-analysis to assess the efficacy and safety of resection of SSPs 10 mm or larger in size. We searched the PubMed/MEDLINE, Google Scholar, Embase, and Cochrane databases for studies reporting data on endoscopic resection of SSPs 10 mm or larger, through May 31st, 2019. The primary outcome was rate of residual SSP, which was the rate of residual SSP found at the polypectomy site during the first follow-up colonoscopy. Secondary outcomes were: technical success (rate of complete macroscopic resection), R0 resection rate (complete histological resection with absence of any polyp tissue at the lateral and deep margins after en-bloc resection), and adverse events (immediate or delayed bleeding and perforation). We performed IQR,group analyses for outcomes based on polyp size and resection techniques. Pooled proportion rates (%) or odds ratio with 95% CIs with heterogeneity (I2) and P < .05. A total of 14 studies met the inclusion criteria: 911 patients (50.2% male; mean age, 62.8 ± 4.9 years) who underwent resection of 1137 SSPs (574 SSPs ≥ 20 mm) with a median polyp size of 19.4 mm (interquartile range, 15.9-29.6 mm). Follow-up information was available for 832 SSPs with a median follow-up duration of 12 months (interquartile range, 6-22.5 months). Piecemeal resection was performed in 58.5% SSPs. The pooled residual SSP rate was 4.3% (95% CI, 2%-6.5%). There was a higher residual SSP rate for polyps ≥ 20 mm compared to 10-19 mm (5.9% vs 1.2%; odds ratio, 3.02; 95% CI, 1-9.2; P = .049). Cold endoscopic mucosal resection (EMR) had significantly lower rates of delayed bleeding (0 vs 2.3%; P = .03) and residual polyp rate (0.9% vs 5%; P=.01) compared to hot EMR, based on univariate analysis. In multi-variate analysis there was no difference in residual polyp rate. There was no significant difference in other outcomes based on the size or method of resection. In a systematic review and meta-analysis, we found that SSPs ≥ 10 mm can be safely resected with low residual polyp rates. Polyp size ≥ 20 mm is a significant factor for residual polyp. Compared to hot EMR, cold EMR is associated with a lower rate of delayed bleeding. Randomized controlled trials comparing hot and cold resection are needed to standardize techniques and optimize outcomes.