Large Sessile Research Articles

First experience of one and two-step endoscopic submucosal dissection of colorectal neoplasms

Aim. To analyze the results of one and two-step endoscopic submucosal dissection in the treatment of colorectal neoplasms.
 Methods. Between 2018 and 2019, 17 patients (6 men and 11 women) aged 33 to 79 years underwent 21 endoscopic submucosal dissections of colorectal neoplasms ranging in size from 1.0 to 6.0 cm. Submucosal fibrosis was identified in 2 (11.8%) patients, epithelial neoplasms in 15 (88.2%) patients including laterally spreading tumors in 9 (60%), and large sessile colorectal polyps in 6 (40%) patients. Histological examination revealed a carcinoid tumor (11.8%), adenoma with low-grade (64.7%) and high-grade (23.5%) intraepithelial neoplasia. 13 patients were subjected to the one-step operation, and 4 patients required the two-step operation with a 1-day interval. Follow-up examinations after the operation were performed, on average, between 2 and 6 months.
 Results. En bloc endoscopic submucosal dissection was performed in 11 (64.7%) patients, 4 of them in combination with mucosal resection. Endoscopic piecemeal resection of the neoplasia was performed in 6 (35.3%) patients. The average operative time was 15573 minutes (range 40320 min). Intraoperative complications, which were eliminated endoscopically, occurred during 8 (38.1%) of 21 operations: intensive bleeding in 6 (75%) patients, diastasis of muscle fibers in 1 (12.5%) patient, perforation of the intestinal wall in 1 (12.5%) patient. At the follow-up at 6 months, all patients formed the scar at the surgical area, while 3 patients required endoscopic removal of residual adenoma 2 months after the operation.
 Conclusion. Endoscopic submucosal dissection is an effective method for removing colorectal neoplasms, while two-step dissection is a promising approach to the development of the technique.Keywords: one and two-step dissection, endoscopic submucosal dissection (ESD), colorectal neoplasms.

Tu1102 EFFICACY AND SAFETY OF COLD ENDOSCOPIC MUCOSAL RESECTION OF LARGE COLONIC ADENOMAS

Cold snare polypectomy is safe, and recent studies have shown a high level of efficacy for large sessile serrated lesions. In contrast, data on cold resection of large adenomas are limited, with previous studies utilizing high rates of adjuvant therapy (biopsy forceps or argon plasma coagulation). The aim of this study was to evaluate the safety and efficacy of a standardised cold EMR technique for large (≥20mm) colonic adenomas. We retrospectively analysed all consecutive large adenomas removed by cold EMR by the study endoscopists at a single academic endoscopy centre between June 2015-May 2019. High definition cap-fitted colonoscopy was performed with a standardized cold EMR technique1: a) submucosal injection of succinylated gelatin with methylene blue or indigo carmine; b) piecemeal cold snare resection with at least 3mm margin of normal mucosa; and c) targeted clip placement for persistent or focal ooze when early post-procedural anticoagulation was planned. Adjuvant therapy was never applied. All specimens were reviewed by a specialist GI pathologist. First surveillance colonoscopy (SC1) was performed at 3-6 months and SC2 at subsequent 6-12 months. Structured scar assessment involved white light and narrow band imaging examination. Flat bland scars were assessed endoscopically; non-bland scars were biopsied; suspected residual adenoma was treated by cold snare or cold biopsy avulsion followed by snare tip soft coagulation. 100 adenomas were removed in 93 patients over 51 months (mean age 68 years, 53 % female). Mean polyp size was 26mm (median 23mm, 20-70mm), 90% were located in the proximal colon and were predominantly Paris 0-IIa morphology (87%). Final histology was tubular/tubulovillous adenoma in 93 (58 low grade and 35 high grade dysplasia) and traditional serrated adenoma in 7. Unanticipated unifocal low risk submucosal invasive adenocarcinoma was present in a single case. A median of 2 clips were placed in 21 defects (23%). Adverse events occurred in 4 (4%); delayed bleeding 2 (2%) and hospitalisation for mild abdominal symptoms in 2 (2%). SC1 is complete for 95 (95%) lesions with surveillance of 3 lesions pending. No residual was detected in 88/95 (endoscopic 38, biopsy 50) at SC1. Residual neoplasia was identified in 7/95 (7.36%) and was treated endoscopically. All residual cases have completed SC2; 5 (71%) had no residual and 2 had further residual treated and are awaiting SC3. Overall SC2 is complete in 52 (52%) and residual was not detected in any additional cases. Selected large colonic adenomas can be safely removed by cold EMR with a low rate of residual neoplasia. Further study is required comparing cold and conventional EMR to further define which lesions and patients are best served by cold resection.

Tip-in endoscopic mucosal resection for large colorectal sessile polyps.

Tip-in endoscopic mucosal resection (EMR) is a modified EMR technique using which en bloc resection of large colorectal sessile polyps can be performed; however, its usefulness for colorectal sessile polyps of > 20mm has not been reported. This study examined treatment outcomes of tip-in and conventional EMR for large colorectal sessile polyps of ≥ 20mm. This was a retrospective case-control study conducted at a single tertiary center in Japan. Subjects included those with large colorectal sessile polyps of ≥ 20mm, excluding pedunculated-type polyps, who underwent endoscopic resection between January 2010 and January 2019. The primary outcome was endoscopic treatment outcomes when using tip-in and conventional EMR, and the secondary outcome was the local recurrence rate after endoscopic treatment. Forty-three colorectal lesions were treated using tip-in EMR and 83 using conventional EMR. Tip-in EMR had a significantly higher en bloc resection rate (90.7% vs. 69.8.%), and significantly shorter treatment duration (6.64 ± 0.64min vs. 10.47 ± 0.81min) than conventional EMR. However, for lesions > 30mm, en bloc resection rate was 50.0% and 52.6% for tip-in and conventional EMR, respectively, indicating no significant difference. Perforation rates with tip-in and conventional EMR were 4.6% and 3.6%, respectively, indicating no significant difference. Local recurrence was examined in 80 cases who were followed up for > 6months after endoscopic resection; recurrence rate was 0% and 7.0% in tip-in and conventional EMR cases, respectively, without significance difference. Tip-in EMR showed high en-block resection rate, particularly in polyps of < 30mm, and no residual tumor was found. This technique is a potential endoscopic treatment alternative for large colorectal sessile polyps of ≥ 20mm.

A simple and cost-effective method: piecemeal cold snare polypectomy without injection for a large sessile serrated lesion≥20mm.

A simple and cost-effective method: piecemeal cold snare polypectomy without injection for a large sessile serrated lesion≥20mm.

Comatulids (Crinoidea, Comatulida) chemically defend against coral fish by themselves, without assistance from their symbionts

Symbiotic associations between small animals and relatively large sessile invertebrates that use taste deterrents for protection are widespread in the marine environment. To determine whether the symbionts are involved in the chemical protection of their hosts, the palatability of ten species of comatulids and six species of their symbionts was evaluated. Taste attractiveness was determined by offering agar pellets flavoured with extracts of comatulids and their symbionts for four coral reef fish species. Five species of symbiont were highly palatable, and one was indifferent to the taste. Almost all comatulids were distasteful, while their aversiveness was different for different fish. These findings indicate that comatulids chemically defend themselves without assistance from symbionts, and the taste deterrents are not universal and can only be effective against particular predators. The presence of tasteful symbionts reduces the security of their hosts by provoking attacks of predators and may impact on the individual and population fitness of comatulids. However, the chemical protection of comatulids is useful for symbionts and undoubtedly increases their survival. Obtained results allows the relationship between comatulids and their symbionts considered commensalism. Most likely, similar relationships can be established in many other associations, where symbionts inhabit chemically defended coral reef invertebrates.

A rare localization of a sessile osteochondroma on the scapula causing shoulder pain in an adolescent girl

Osteochondromas are common primary bone tumors which are usually found in the metaphyseal region of tubular long bones. The distal femur, proximal tibia and the proximal humerus account for 90% of the common sites of occurrence. Their occurrence in flat bones such as the pelvis and the scapula are rare and constitute only 3-4% of all osteochondromas. While the scapula is rarely involved, this is the most common tumor of the scapula. Clinical signs of this lesion include shoulder pain and limited range of motion. This tumor may also present with winging of the scapula. We report a case of a 15-year-old girl presenting with a large sessile osteochondroma of the scapula causing pain on shoulder movements. While osteochondromas of the scapula are rare, it is important to recognise that the most common benign bone tumor of the scapula is an osteochondroma. Due to the unusual location with unspecific shoulder pain, the diagnosis may be hindered. Osteochondromas may have different symptoms depending on their location. Good functional outcomes can be expected following excision of scapular osteochondromas as evidenced by this patient. The prognosis is mostly excellent following excision, but the possibility of recurrence must be kept in mind if the excision is inadequate.

A105 ENDOSCOPIC MUCOSAL RESECTION (EMR) OF LARGE SESSILE POLYPS: DATA FROM A MULTI-CENTER HEALTH ZONE

Abstract Background EMR is the standard of care for management of large non-invasive colonic polyps. Current guidelines recommend repeat colonoscopy within 6 months after EMR of large sessile polyps to assess the EMR site for residual adenoma. We reviewed the outcomes and compliance to these guidelines in patients at the University of Alberta Hospital (UAH) and surrounding 7 hospitals. Aims The primary outcome was the proportion of patients who received a follow up colonoscopy within 180 days. Methods Retrospective data was collected on consecutive patients who had a large polyp resection (size &amp;gt;2cm as documented per endoscopy report) from January 1st, 2014 to January 1st, 2016. Information was collected on patients from UAH as well as seven surrounding hospitals within the Edmonton geographic zone. Data was extracted from electronic health records. Results Of 258 patients identified patients, 250 had complete data. Of these 250 patients, 151 (60.4 %) were male and median age was 67 (IQR 60 - 72). Eighty-two cases (32.8%) were performed at UAH, with 168 cases (67.2%) at other hospitals. Polyps were removed by gastroenterologists (n=215, 86.0%), surgeons (n=26, 10.4%), and others (n=9, 3.6%). Fifty-two patients (20.8%) had no formal follow up on electronic health records, while 198 patients (79.2%) had a repeat colonoscopy. 57 patients (29.1 %) had a repeat colonoscopy within 180 days. The median follow-up time was 224 days (IQR 172–365). Of the 82 cases performed at UAH, 74 (90.2%) had follow up. Out of the 168 cases at the other hospitals, 124 (73.8%) had follow up (p&amp;lt;0.01). Sixteen (21.9%) and 41 (33.3%) cases were followed up within 180days at UAH and other hospitals, respectively (p=0.09). Of the 74 cases with follow up at UAH, 12 (15.7%) had residual tissue confirmed by pathology. Of the 124 cases at other hospitals, 26 (21.0%) had follow up (p=0.41). Median polyp size was 2.5cm (IQR 2.0cm - 3.5cm) Conclusions Only 29.1% of patients with large sessile polyp removal in the Edmonton zone had a repeat colonoscopy within 180 days. Patients with large polypectomy performed at the academic hospital were more likely to be followed up compared to non-academic hospitals. Further validation studies with larger data sets are needed. These findings highlight the need for standardized pathways to appropriately manage and survey large polyps post-EMR. Funding Agencies None

Underwater endoscopic mucosal resection without submucosal injection (UEMR) for large colorectal polyps: A community-based series

BackgroundUnderwater endoscopic mucosal resection without submucosal injection (UEMR) is an appealing therapy for large colorectal polyps. However, this technique is not practiced widely and there are limited data evaluating UEMR in community settings. MethodsThe study comprised patients undergoing UEMR of large (≥20 mm) sessile colorectal lesions at a community-based center. Residual neoplasia was assessed via follow-up colonoscopy. ResultsAmong 264 lesions (diameter 38 ± 18 mm; range 20–110 mm) 99% were successfully resected with UEMR. Two lesions involving the cecum/IC valve required multiple sessions. There were no cases of perforation or post-polypectomy syndrome. Delayed bleeding occurred in 1.6%, all managed conservatively. Residual neoplasia was present in 5.7% and was amenable to UEMR. ConclusionThis large community-based series demonstrated high efficacy and safety of UEMR for large sessile colorectal lesions. The results support UEMR as first-line therapy for these lesions. SummaryUnderwater endoscopic mucosal resection without submucosal injection (UEMR) is a recently developed method that has advantages over conventional EMR for treatment of large colorectal lesions. However, UEMR is not practiced widely and there are limited data evaluating this technique in everyday practice. This large community-based series demonstrated high efficacy and safety of UEMR for large sessile colorectal lesions.

Consecutive cold/hot underwater snaring with a single hybrid snare for resection of large sessile serrated lesions when cold snaring fails

Consecutive cold/hot underwater snaring with a single hybrid snare for resection of large sessile serrated lesions when cold snaring fails

Underwater EMR of a colonic adenoma surrounded by diverticula.

An 83-year-old man with positive fecal occult blood test results underwent colonoscopy, which revealed a 15-mm-diameter laterally spreading tumor surrounded by multiple diverticula at the ascending colon (Figs. 1 and 2). The lesion was a nongranular-type laterally spreading tumor, and the Japanese Narrow-Band Imaging Expert Team classification was type 2A, meaning no evidence of invasion; therefore, we performed endoscopic resection instead of surgery.Figure 2Endoscopic image showing the tumor well demarcated with indigo carmine.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Conventional EMR of the tumor surrounded by diverticula with the use of submucosal saline solution injection would have been difficult because the appropriate lifting up by submucosal injection is difficult, and snaring including adjacent diverticula would have resulted in perforations. Furthermore, endoscopic submucosal dissection (ESD) for tumors adjacent to diverticula carries a high risk of perforation, and performing ESD on such lesions demands highly advanced skills, although we have reported success with the use of ESD for colonic polyps involving a diverticulum.1Shichijo S. Matsuno K. Takeuchi Y. et al.Pulley traction-assisted colonic endoscopic submucosal dissection affords good visibility of submucosal layer.VideoGIE. 2018; 3: 358-360Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar,2Shichijo S. Yamasaki Y. Takeuchi Y. Case of colonic adenoma involving a diverticulum resected by a traction-assisted endoscopic submucosal dissection technique.Dig Endosc. 2017; 29: 729-730Crossref PubMed Scopus (17) Google Scholar Underwater EMR was developed and described by Binmoeller et al3Binmoeller K.F. Weilert F. Shah J. et al."Underwater" EMR without submucosal injection for large sessile colorectal polyps (with video).Gastrointest Endosc. 2012; 75: 1086-1091Abstract Full Text Full Text PDF PubMed Scopus (206) Google Scholar in 2012. We previously reported the usefulness of this procedure with a high en bloc resection rate for intermediate-sized colorectal polyps4Yamashina T. Uedo N. Akasaka T. et al.Comparison of underwater vs conventional endoscopic mucosal resection of intermediate-size colorectal polyps.Gastroenterology. 2019; 157: 451-461.e2Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar; therefore, we performed underwater EMR for this lesion (Video 1, available online at www.VideoGIE.org). We here report the first case, to our knowledge, of a colonic adenoma surrounded by diverticula treated with underwater EMR. We used a magnifying colonoscope (Evis PCF-Q260ZAI; Olympus Medical Systems, Tokyo, Japan). Air was evacuated from the affected segment of the lumen and infused water until the lumen was completely full, after which we performed hot-snare polypectomy without submucosal injection, using a SnareMaster (15 mm; Olympus Medical Systems) (Fig. 3). A high-frequency electrical generator (Vio 300D; Erbe Elektromedizin, Tübingen, Germany) was used with the following settings: endocut Q mode: effect 3, duration 2, interval 4. We resected the lesion en bloc in 2 minutes without perforation and completely closed the mucosal defect with clips (Figs. 4 and 5). No adverse events occurred, and the patient experienced no postoperative abdominal pain or fever requiring antibiotics. On pathologic examination, the lesion was a tubular adenoma, high-grade in part, with negative margins (Fig. 6).Figure 4Endoscopic image showing completed underwater EMR.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 5Endoscopic image showing complete closure of the defect with clips.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 6Photograph of the specimen after it was resected en bloc in 2 minutes.View Large Image Figure ViewerDownload Hi-res image Download (PPT) All authors disclosed no financial relationships relevant to this publication. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJjOWE4NzBhZThjMTAyNjRmNTMyMWUzMThjM2U0OTJhNiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjc4MDA4Njc1fQ.ojSWMYGdEpn8sb_Vue33TsVsQk4sx0xrnjsYhN0e_DMlvnvbvi5PS7yv2mRUWzp3aWHkwZ4DJoK_nBNhCPKTdkB4F-kWgbyJUoHLKX-Wmq3WgmsVAB7rESbsA-KJA1m88IGz7HnhNTBBdva_Y-l26Ngn1miP5yyC9XT5ZVGfCjWvecCVo_hEJW_mHgjtsoOZ7OPrY-u8tb-Xx4tDpXt02RazLx4tDvP4H2nsA00kITkefKFvNuW-xE7zwOvGY82EkSh-eF7LSqwaA-uLhLrVmQb-OqrnZzW2Nxnbn-qa2NBulHuER2Ie6ppmB_x4TSRdEXfxLjxmy7Soh5Bp0OQrOA Download .mp4 (31.25 MB) Help with .mp4 files Video 1Underwater EMR of the colonic adenoma surrounded by diverticula.

Cold snare piecemeal EMR of large sessile colonic polyps ≥20 mm (with video)

Conventional EMR using a hot snare is the standard of care for resection of large (≥20mm) nonmalignant sessile colonic polyps. Serious adverse events are predominantly because of electrocautery. This could potentially be avoided by cold snare piecemeal EMR (CSP-EMR). This study aimed to evaluate the safety and efficacy of CSP-EMR of sessile colonic polyps sized≥20mm. All cases of CSP-EMR at 5 Australian academic hospitals for sessile polyps≥20mm over a 2-year period, from January 2016 to December 2017, were identified retrospectively. Efficacy was defined as the absence of residual or recurrent polyp tissue during the first surveillance colonoscopy (SC1) and second surveillance colonoscopy (SC2). Clinically significant intraprocedural or delayed adverse events and surveillance colonoscopy findings were assessed by reviewing medical records. CSP-EMR was performed on 204 polyps sized≥20mm in 186 patients (men, 33.8%; median age, 68 years). SC1 for 164 polyps (80.4%) at a median interval of 150 days showed residual or recurrent polyp in 9 cases (5.5%; 95% confidence interval, 3%-11%). SC2 for 113 polyps (72.9%) at a median interval of 18 months showed late residual or recurrent polyp in 4 cases (3.5%; 95% confidence interval, .9%-8.5%) after a normal SC1. Intraprocedural bleeding was successfully treated in 4 patients (2.2%), whereas 7 patients (3.8%) experienced self-limited clinically significant post-EMR bleeding and 1 patient (.5%) required overnight observation for nonspecific abdominal pain that resolved spontaneously. None experienced other adverse events. CSP-EMR of sessile colonic polyps≥20mm is technically feasible, effective, and safe. The adverse event rate and polyp recurrence rate were low. Randomized or large prospective trials are required to confirm the noninferiority and improved safety of CSP-EMR compared with conventional EMR and to further determine the polyp morphologies that are best suited for CSP-EMR.

Surgical versus endoscopic resection of large sessile duodenal and papillary lesions.

Data on the endoscopic resection of duodenal and papillary lesions less than 15 mm in size have been well supported by systematic studies. However, for large sessile lesions of the duodenum or papilla (LSL-D/P), surgery is often performed despite significant morbidity and mortality. This study aimed to compare the outcomes and costs between endoscopic and surgical resection of such lesions. Patients who underwent endoscopic or surgical resection of LSL-D/P at Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University from 2013 to 2017 were retrospectively analyzed. Endoscopic and surgical outcomes and costs were compared. A total of 68 lesions were evaluated (47.1% of patients were male; mean lesion size 25 mm); 46 were treated by endoscopic resection, and 22 were managed by surgical resection. At the initial procedure, complete resection was achieved in 93.4%. Major complications (perforation, delayed bleeding, pancreatitis, infections and admission to the ICU) occurred in 15.3% of the endoscopic group and 22.6% of the surgical group. For recurrence at the first surveillance endoscopic examination, there was a 12.1% recurrence rate in the endoscopic group and a 5.3% recurrence rate in the surgical group (P = 0.654). Compared with surgical resection, regardless of lesion location, endoscopic resection had a shorter procedural time and hospital stay, a lower morbidity rate and was less costly. In centers specialized in complex endoscopic resection, patients with LSL-D/P would likely benefit from advanced endoscopic management, which offers a lower morbidity profile and reduced costs.

Proposal and applicability of a method to evaluate surface tension of liquid using large volume sessile drop in gravity

Early cancer diagnosis and treatment are crucial research fields of human health. One method that has proven efficient is biomarker detection which can provide real-time and accurate biological information for early diagnosis. This review presents several biomarker sensors based on electrochemistry, surface plasmon resonance (SPR), nanowires, other nanostructures, and, most recently, metamaterials which have also shown their mechanisms and prospects in application in recent years. Compared with previous reviews, electrochemistry-based biomarker sensors have been classified into three strategies according to their optimizing methods in this review. This makes it more convenient for researchers to find a specific fabrication method to improve the performance of their sensors. Besides that, as microfabrication technologies have improved and novel materials are explored, some novel biomarker sensors-such as nanowire-based and metamaterial-based biomarker sensors-have also been investigated and summarized in this review, which can exhibit ultrahigh resolution, sensitivity, and limit of detection (LoD) in a more complex detection environment. The purpose of this review is to understand the present by reviewing the past. Researchers can break through bottlenecks of existing biomarker sensors by reviewing previous works and finally meet the various complex detection needs for the early diagnosis of human cancer.

Application of KeyPort access to transanal endoscopic mircrosurgery

Objective: To explore the effectiveness of KeyPort access in transanal endoscopic mircrosurgery (TEM). Methods: A descriptive case series study was performed. Clinicopathological data of 20 patients undergoing KeyPort access TEM in Beijing Chaoyang Hospital of Capital Medical University from December 2016 to April 2018 were collected and analyzed retrospectively. Procedure of KeyPort access TEM: general anesthesia or combined spinal epidural anesthesia (CSEA); lithotomy or prone jack-knife position; anal dilation; placement of the KeyPortaccess; connection of TEM pneumoperitoneum device, light source and imaging equipment; placement of 5 mm dedicated endoscope; insufflation of CO2 with pressure of 1.6-2.0 kPa (12-15 mmHg); after rinsing the intestinal lumen, circular resection marginlabeled by the needle-shaped electrocautery;electric coagulation or ultrasonic knife used to perform a full-thickness resection with a 0.5 cm-1 cm margin along the marking line. Indications of KeyPort access TEM: (1) benign large sessile polyps which were difficult to resect under colonoscopy; (2) submucosal lesions with diameter <2 cm; (3) Tis and T1 stage rectal carcinoma without lymph node metastasis; (4) palliative resection of T2 stage rectal carcinoma without lymph node metastasis. Contraindications: (1) accompanying serious diseases without the tolerance of anesthesia and operation; (2) distance from lesion to anal verge >20 cm. Results: There were 10 males and 10 females with age of (63±15) years old and BMI of (24.5±3.3) kg/m(2). The diameter of the lesions was (2.0±1.3) cm, and the distance from lesion to anal verge was (6.2±2.2) cm. One patient had 3 lesions at different positions in rectum with diameters of 0.5 cm, 0.5 cm, and 1 cm, respectively. All operations were accomplished through the KeyPort access TEM and no case was transferred to other methods. The duration of surgery was 75 (30-220) minutes; intraoperative blood loss was 10 (0-30) ml. Two patients with rectal anterior wall lesions underwent full-thickness resection of the intestine wall reaching the peritoneal reflex with penetration into the peritonealcavity, and received suture closure immediately. For the patient with 3 rectal lesions, the 1.0 cm lesion received a full-thickness resection and the other 2 lesions received submucosal resection. No postoperative complication occurred. Postoperative pathology showed that there were 1 case of chronic inflammatory lesion, 4 cases of benign tumor, 3 cases of carcinoma in situ, 4 cases of neuroendocrine tumor, 6 cases of pT1 rectal cancer, 2 cases of pT2 rectal cancer (both invading the superficial muscle layer). The median hospital stay was 6 (3-7) days. The postoperative follow-up was (7.2±3.8) months. No postoperative complication or recurrence was observed. Conclusion: TEM with KeyPort access is safe, rapid and effective in the treatment of rectal tumors.

Management of villous adenoma - beyond endoscopic techniques

Polyp’ is a descriptive term for abnormal projection above an epithelial surface and is not a histological diagnosis. Adenoma is a benign neoplasm of glandular origin and is significant because they are cancers in making. Once a polyp is found, it must be removed in total. Attempts at estimating the polyp histology by endoscopic appearance are often incorrect. With recent advances in endoscopic techniques, most of the polyps are removable through endoscopy. However, there remain a few situations depending on location, size of the lesion and endoscopic expertise available, where complete removal of the polyp requires surgical intervention especially so for large sessile adenomas. We are presenting here four cases of villous adenoma requiring surgical intervention each managed differently depending on presentation and overall clinical picture.

Long-term follow-up after EMR of large colorectal lesions: metachronous lesions, predictors and surveillance timing

Background: Endoscopic mucosal resection (EMR) is the first-line approach to large colorectal sessile lesions. These patients have been associated with high rates of metachronous lesions (ML), but long-term follow-up (LtFU) data are lacking. We aimed at evaluating the efficacy of an LtFU protocol and analyse the development and risk factors for ML.Methods: A prospectively collected database was analysed. Seventy-six patients submitted to EMR of large colorectal sessile lesions between 2007 and 2013 complied with a specific endoscopic surveillance, consisting of two protocols – initial follow-up (iFU) and LtFU. iFU intended to inspect the mucosectomy scars twice (at 3–6 and 12 months) and remove synchronous lesions (SL). Protocol examinations of LtFU were carried out at the first- and fourth-year post-iFU, aiming to remove ML. Statistical analysis included variables related to patient, index lesion, SL and ML characteristics.Results: Rates of ML were 39.5% and 20.4% at the first- and fourth-year of LtFU, and respectively 11.8% and 3.7% of them were advanced ML. All ML were endoscopically resectable. At univariate analysis, male gender (OR: 2.91; p=.029), the presence of SL (OR 3.86, p=.010) and advanced SL (OR 4.25, p=.006) were risk factors for ML. At multivariate analysis, male gender (p=.031) and advanced SL (p=.006) were significant predictors of ML development.Conclusions: We confirmed the increased risk of ML in patients with large colorectal lesions. A significant number of advanced ML was removed at the first LtFU colonoscopy, probably it should be carried out earlier than currently recommended.

Safety and efficacy of tip‐in endoscopic mucosal resection for large sessile colorectal polyps: A single‐center experience in Taiwan

AbstractEndoscopic mucosal resection (EMR) is an established technique for treating large colonic polyps. However, en bloc resection of large sessile lesions using conventional EMR is technically challenging and can generally be performed only in a piecemeal manner, resulting in low radical resection rates and high recurrence rates. Endoscopic submucosal dissection (ESD), a more difficult and time‐consuming technique, is an alternative procedure with high en bloc resection rates and low recurrence rates. Therefore, we present a novel technique: tip‐in EMR. We evaluated the feasibility and safety of tip‐in EMR for the en bloc resection of large sessile colorectal polyps or laterally spreading tumors (LSTs). In this retrospective observational study, we included patients who underwent tip‐in EMR for the removal of large colonic polyps (&gt;10 mm) at Shuang Ho Hospital over a 2‐year period (September 2015 to September 2017). Clinical variables, including age, gender, polyp size and morphology, procedure time, complications, and pathology, were analyzed. A total of 46 polyps were removed from 42 adult patients through tip‐in EMR. The patients' mean ± SD age was 61.0 ± 12.0 years. The polyps were located in the right‐side colon, transverse colon, left‐side colon, and rectum in 39.1%, 17.4%, 37.0%, and 6.5% of the patients, respectively. The mean polyp size was 20.4 ± 5.6 mm (range = 10‐35 mm). LSTs were the predominant polyp type (n = 37, 81.5%). Among all LSTs (n = 37), 12 lesions were of granular type, and 25 lesions were nongranular. All polyps were removed en bloc using tip‐in EMR. The mean procedure time was 14.9 ± 8.8 min. Immediate bleeding occurred in only one patient (2.2%). No patient developed perforation or delayed bleeding. Regarding histopathological findings, 9 polyps (19.6%) were sessile serrated adenomas, 16 (34.8%) were tubular adenomas, 12 (26.1%) were tubulovillous adenomas, and 1 (2.2%) was a villous adenoma. High‐grade dysplasia was observed in four polyps (8.7%), and one lesion was an in situ carcinoma. Surveillance colonoscopy was performed in 20 patients (47.6%) over a mean follow‐up period of 12.7 ± 5.3 months. Among these patients, only one patient exhibited local recurrence. Tip‐in EMR is a novel alternative technique for polyp resection that is proven to be relatively safe and efficient for the en bloc removal of large sessile colonic polyps.

Clinical and financial impacts of introducing an endoscopic mucosal resection service for treatment of patients with large colonic polyps into a regional tertiary hospital.

Background and study aims Endoscopic mucosal resection (EMR) of large sessile or laterally spreading colonic lesions is a safe alternative to surgery. We assessed reductions in Surgical Resection (SR) rates and associated clinical and financial benefits following the introduction of an EMR service to a large regional center. Patients and methods Ongoing prospective intention-to-treat analysis of EMR was undertaken from time of service inception in 2009 to 2017. Retrospective data for SR of large sessile/laterally spreading colonic lesions were collected for the period 4 years before commencement of the EMR service (2005 – 2008) and 9 years after its introduction (2009 – 2017). Results From 2005 to 2008, 32 surgical procedures were performed for non-malignant colonic neoplasia (50 % male, median age 68 years, median Length of Stay (LoS) 10 days). Following the introduction of the EMR service, there was a 56 % reduction in the number of patients referred for surgery (32 surgical procedures, 47 % male, median age 70 years, median LoS 8.5 days). During this period, EMR was successfully performed in 183 patients with 216 lesions resected (60 % male, median age 68 years, median LoS 1 day). Compared to the SR group, the EMR cohort had a lower peri-procedural complication rate (7.7 % vs 54.7 %, P < 0.0001), and shorter average LoS (1 vs 9 days, P < 0.0001). A cost saving of AUD $ 19 543.5 was seen per lesion removed with EMR compared to SR. Conclusions The introduction of a dedicated EMR service into a large regional center as an alternative to SR can lead to a substantial decrease in unnecessary surgery with subsequent clinical and financial benefits.

549 Efficacy and Safety of Non-Elevated Piecemeal Polypectomy Using Hot Snare

INTRODUCTION: Piecemeal polypectomy refers to the removal of large sessile colonic polyps by means of multiple snarings and is commonly performed after submucosal injection of a liquid, typically normal saline. Some reports suggest submucosal injection may not be benign, due to concerns of needle tracking of neoplastic cells, and difficulty in removal of recurrences due to scarring after injection. There is a paucity of recent literature describing polypectomy without submucosal injection. Historically, non-elevated piecemeal polypectomy has been criticized for concerns regarding bleeding and perforation. The purpose of this study was to describe a retrospective review of colonic polyps removed using non-elevated piecemeal polypectomy and associated outcomes. METHODS: An outpatient endoscopy center database was searched for patients who had large (≥3.0) sessile polyps excised using non-elevated piecemeal polypectomy technique between December 2012 and December 2018. All polyps with invasive cancer were excluded (n = 3). Chart review was carried out to extract demographic data, outcomes and adverse events. Details of all subsequent colonoscopies, including recurrences, residual tissue, or need for surgery were recorded. RESULTS: During the study period, 73 patients underwent 78 non-elevated piecemeal polypectomies for polyps ≥3 cm. There were 27 (37%) female patients and 46 (63%) male patients. Most common polyp sizes were between 3.5 cm to 3.9 cm (48.7%) or ≥4 cm (52.6%). Tubulovillous adenoma was the most frequent histological subtype (48.7%). Most polypectomies occurred in the right colon (54.4%). There were zero events of perforation. Ten (12.6%) patients had intraprocedural bleeding controlled endoscopically. Four patients (5.1%) had post-procedural bleeding, 3 required colonoscopy and clip hemostasis. There were 10 recurrences (12.8%), nine were found at the first endoscopic follow up and controlled by means of non-elevated hot snare polypectomy. One patient had a persistent recurrence and required subsequent surgical management for an adenocarcinoma. CONCLUSION: Non-elevated piecemeal polypectomy with hot snare is a safe and effective technique for the removal of large sessile (≥3 cm) colonic polyps. Perforation and bleeding are uncommon. Recurrences are easily controlled by additional hot snare resection.

574 Role of Prophylactic Endoscopic Clipping for Prevention of Delayed Post-Polypectomy Bleeding: Meta-Analysis of Randomized Controlled Trials

INTRODUCTION: Post-polypectomy bleeding is a common complication of colonoscopy. Several endoscopic techniques including prophylactic endoscopic clip placement are used for prevention of post-polypectomy bleeding. However, several studies have reported mixed results on the efficacy of this approach. We conducted a meta-analysis of randomized controlled trials (RCTs) to assess the efficacy of prophylactic endoscopic clipping for prevention of delayed post-polypectomy bleeding. METHODS: Several databases (Embase, Pubmed, Cochrane database, Google Scholar) and abstracts of gastrointestinal and surgical meetings were searched extensively for relevant articles. Studies comparing prophylactic endoscopic clipping alone to standard colonoscopy with no endoscopic clipping were included. Studies that combined prophylactic clipping with other hemostatic techniques were excluded. Data was extracted using a standard form by two reviewers. Data regarding patient characteristics, types of polyps resected, post-polypectomy bleeding and other complications were extracted. Effect sizes were computed either using the fixed effects or random effects model using the Comprehensive Meta-analysis software. Publication bias, quality of studies and heterogeneity were analyzed. RESULTS: Nine RCTs were included in this study. The studies recruited subjects from USA, Japan, Canada and Spain. There were 3762 controls and 3658 patients in the treatment arm. Studies evaluated both small (&lt;20mm) and large polyps (&gt;20 mm), sessile and pedunculated polyps. The polyps were predominantly removed with standard polypectomy or endoscopic mucosal resection (for larger polyps). Delayed post-polypectomy bleeding occurred in 2.4% of controls and 1.6% in patients with endoscopic clipping. On analysis of all polyps, prophylactic endoscopic clipping decreased the risk of delayed post-polypectomy bleeding (RR = 0.71: 95% CI 0.51-0.99, P = 0.04, I2= 20%). The risk reduction was seen mainly with larger polyps(&gt;20 mm), RR = 0.53 (95% CI : 0.32-.90, P = 0.02, NNT 28) and with sessile polyps (RR = 0.52, 95% CI: 0.32-0.83, P = 0.006, NNT 100). The protective effect was not seen for small polyps (&lt;20 mm) (P = 0.91, P = 0.7) or pedunculated polyps (RR = 0.58, P = 0.29). All studies were of high quality. No publication bias or heterogeneity was present. CONCLUSION: Prophylactic clipping decreased the risk of delayed post-polypectomy bleeding. The benefit was mainly seen in patients with sessile polyps or large polyps (&gt;20 mm).