Laterally Spreading Tumors Research Articles

Granular Mixed Laterally Spreading Tumors: What Is the Risk for Covert Cancer?

Colorectal laterally spreading tumors (LSTs) — defined as nonpolypoid lesions ≥1 cm with lateral growth — can sometimes harbor covert (not

Mo1670 EFFICACY AND SAFETY OF ESTD AND ESD IN THE TREATMENT OF LARGE AREA RECTAL LATERALLY SPREADING TUMORS

This study aims to compare the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) and endoscopic submucosal dissection (ESD) in the treatment of large area rectal laterally spreading tumors (LST). The clinical data, operation procedures and pathology of rectal LST treated with ESD and ESTD from August 2011 to February 2019 in the Center of Digestive Endoscopy, West China Hospital of Sichuan University were retrospectively analyzed. The rates of en bloc, curative resection, complications and recurrence of tumors were compared and analyzed, then we evaluated the safety and effectiveness of ESD and ESTD in the treatment of large area LSTs. There were 122 patients with rectal LST in ESD and ESTD groups. The lesion area was 12.6±14.1 cm2, 24.5±19.9 cm2, respectively, p < 0.001.;the en bloc resection rate was 88.3% ,97.8%,respectively,p=0.066; the dissection speed was 23.3±18.3 mm2/min, 27.1±13.2 mm2/min, respectively, p=0.239; the curative resection rate was 98.7%, 86.7%, respectively,p=0.006; There were 7 cases of non-curative resection in the two groups after operation, of which 6 cases underwent additional surgery. Postoperative complications were mainly fever and hematochezia without endoscopic intervention, with fewer serious complications. The overall canceration rate of LST was 17.3%. The follow-up time of the two groups was 16.4 ±16.0 months and 23.20±16.3 months, respectively. Only one case recurred in ESD group. In the analysis of large area lesions(>3cm), there were 90 patients with large area LST, 50 patients in ESD group and 40 patients in ESTD group .The lesion areas of the two groups was 17.4±15.5 cm2 , 26.0±19.8cm2, respectively, p=0.025;the en bloc resection rate was 85%, 97.5%, respectively, p=0.034; the dissection speed was 28.4±20.3 mm2/min, 28.3 ±12.9 mm2/min, respectively, p=0.991; the curative resection rate was 92.5%, 100%, respectively, p=0.084. Both ESD and ESTD can safely and effectively resect rectal LST, which was not affected by the size of lesions. There was no significant difference in the dissection speed and the curative resection rate. When large area LST was resected, the rate of en bloc resection of ESTD was higher than that of ESD.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Su1070 ENDOSCOPIC SUBMUCOSAL DISSECTION FOR COLORECTAL LATERALLY SPREADING TUMORS: CLINICAL OUTCOMES AND PREDICTORS OF TECHNICAL DIFFICULTY

Endoscopic submucosal dissection (ESD) has been used for colorectal laterally spreading tumors (LSTs), yet is technically challenging. We aimed to investigate the clinical outcomes of ESD for colorectal LSTs and predictors of technical difficulty. Consecutive patients who underwent ESD for colorectal LSTs in Beijing Friendship Hospital between June 2013 and March 2019 were retrospectively involved. We evaluated the en bloc resection rate, R0 resection rate, curative resection rate and adverse events with per lesion analysis. Dissection with a slow speed (<8mm2/min), conversion to piecemeal resection or abandonment of endoscopic procedure was considered as technically difficult. Factors associated with difficult ESD procedure, including LST subtype, size, non-lifting sign, procedure duration and operator experience (scaled by prior ESD case numbers) were determined using logistic regression. Significant factors with p<0.05 were adjusted in multivariate logistic regression. A total of 322 patients (56.5% men, mean age 64.7 years old) with 335 colorectal LSTs (median size 20.0mm, range 10.0-100.0mm) were enrolled. The proportions of granular (G) subtype and the non-granular (NG) subtype LSTs were 61.9% and 38.1%, respectively (Table 1). The en bloc, R0 and curative resection rate were 90.7%, 76.1% and 73.4%, respectively. The median dissection speed was 8.2mm2/min. Endoscopic procedure was abandoned in 4 lesions (1.2%), and 27 (8.1%) converted to piecemeal resection because of technical difficulty. Four cases (1.2%) had delayed bleeding and treated under endoscopy successfully. Perforation occurred in 10 LSTs (3.0%), of which only 1 (0.3%) needed surgery. Table 2 listed the risk factors for technically difficult ESD. NG subtype (odds ratio [OR] 1.9, p=0.012), positive non-lifting sign (OR 3.2, p=0.012), and less experienced operators (≤60 colorectal ESD cases) (OR 1.8, p=0.019) associated with a slow dissection speed. After adjusted in multivariate analysis, NG subtype (OR 2.2, p=0.004), positive non-lifting sign (OR 3.4, p=0.009), and less experienced operators (OR 2.1, p=0.009) remained to be independent predictors of low speed procedure. Lesions with size ≥20mm (OR 3.6, p=0.004) and positive non-lifting sign (OR 7.5, p<0.001) had higher risk for ESD abandonment or conversion to piecemeal resection due to difficult procedure. After adjustment in multivariate analysis, larger size (OR 8.3, p<0.001) and positive non-lifting sign (OR 13.3, p<0.001) were still significant factors. Procedure with prolonged duration of ≥60min associated with perforation (OR 5.8, p=0.014). ESD is feasible and safe for treating colorectal LSTs. NG subtype, larger size and positive non-lifting sign indicate difficult ESD procedure. The dissection speed can be improved with operator experience increased.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Review on colorectal endoscopic submucosal dissection focusing on the technical aspect

Endoscopic submucosal dissection (ESD) enables removal of broad-based colorectal polyps or lateral spreading tumors with a higher rate of en bloc resection and a lower risk of local recurrence. However, it is technically demanding. Over the past 20years, various equipment and innovative techniques have been developed to reduce the difficulty of ESD. The information in the literature is scattered. Our aim is to provide a comprehensive review on the setup and technical aspects of colorectal ESD. We searched the PubMed database and systemically reviewed all original and review articles related to colorectal ESD. Further manual search according to reference lists of identified articles were done. The selected articles were categorized and reviewed. Original figures were created to help readers understand some of the ESD techniques. A total of 216 articles were identified, in which 25 of them were review articles and 191 of them were original articles. They were categorized and reviewed. An in-depth appraisal of the setting, equipment, and technical aspects of colorectal ESD was performed. Although ESD is a technically demanding procedure that requires expert endoscopic skills, it can be mastered. With good peri-procedural preparation, sufficient knowledge of the equipment, and thorough understanding of the useful endoscopic tricks and maneuvers, colorectal ESD can be performed smoothly and safely.

Treatment policy for colonic laterally spreading tumors based on each clinicopathologic feature of 4 subtypes: actual status of pseudo-depressed type

Laterally spreading tumors (LSTs) are originally classified into 4 subtypes. Pseudo-depressed nongranular types (LSTs-NG-PD) are gaining attention because of their high malignancy potential. Previous studies discussed the classification of nongranular (LST-NG) and granular types (LST-G); however, the actual condition or indication for endoscopic treatment of LSTs-NG-PD remains unclear. We aimed to compare the submucosal invasion pattern of LSTs-NG-PD with the other 3 subtypes. A total of 22,987 colonic neoplasms including 2822 LSTs were resected endoscopically or surgically at Showa University Northern Yokohama Hospital. In these LSTs, 322 (11.4%) were submucosal invasive carcinomas. We retrospectively evaluated the clinicopathologic features of LSTs divided into 4 subtypes. In 267 LSTs resected en bloc, their submucosal invasion site was further evaluated. The frequency of LSTs in all colonic neoplasms was significantly higher in women (14.9%) than in men (11.0%). Rates of submucosal invasive carcinoma were .8% in the granular homogenous type (LSTs-G-H), 15.2% in the granular nodular mixed type (LSTs-G-M), 8.0% in the nongranular flat elevated type (LSTs-NG-F), and 42.5% in LSTs-NG-PD. Tumor size was associated with submucosal invasion rate in LSTs-NG-F and LSTs-NG-PD (P< .001). The multifocal invasion rate of LSTs-NG-PD (46.9%) was significantly higher than that of LSTs-G-M (7.9%) or LSTs-NG-F (11.8%). In LSTs-NG-PD, the invasion was significantly deeper (≥1000 μm) if observed in 1 site. For LSTs-G-M and LSTs-NG-F that may have invaded the submucosa, en bloc resection could be considered. Considering that LSTs-NG-PD had a higher submucosal invasion rate, more multifocal invasive nature, and deeper invasion tendency, regardless if invasion was only observed in 1 site, than LSTs-NG-F, we should endoscopically distinguish LSTs-NG-PD from LSTs-NG-F and strictly adopt en bloc resection by endoscopic submucosal dissection or surgery for LSTs-NG-PD. (Clinical trial registration number: UMIN 000020261.).

Computer aided detection for laterally spreading tumors and sessile serrated adenomas during colonoscopy.

Evidence has shown that deep learning computer aided detection (CADe) system achieved high overall detection accuracy for polyp detection during colonoscopy. The detection performance of CADe system on non-polypoid laterally spreading tumors (LSTs) and sessile serrated adenomas/polyps (SSA/Ps), with higher risk for malignancy transformation and miss rate, has not been exclusively investigated. A previously validated deep learning CADe system for polyp detection was tested exclusively on LSTs and SSA/Ps. 1451 LST images from 184 patients were collected between July 2015 and January 2019, 82 SSA/Ps videos from 26 patients were collected between September 2018 and January 2019. The per-frame sensitivity and per-lesion sensitivity were calculated. (1) For LSTs image dataset, the system achieved an overall per-image sensitivity and per-lesion sensitivity of 94.07% (1365/1451) and 98.99% (197/199) respectively. The per-frame sensitivity for LST-G(H), LST-G(M), LST-NG(F), LST-NG(PD) was 93.97% (343/365), 98.72% (692/701), 85.71% (324/378) and 85.71% (6/7) respectively. The per-lesion sensitivity of each subgroup was 100.00% (71/71), 100.00% (64/64), 98.31% (58/59) and 80.00% (4/5). (2) For SSA/Ps video dataset, the system achieved an overall per-frame sensitivity and per-lesion sensitivity of 84.10% (15883/18885) and 100.00% (42/42), respectively. This study demonstrated that a local-feature-prioritized automatic CADe system could detect LSTs and SSA/Ps with high sensitivity. The per-frame sensitivity for non-granular LSTs and small SSA/Ps should be further improved.

The Coexistence of Colorectal Polyps in the Right Colon Increases the Malignant Risk of Laterally Spreading Tumors.

Background The coexistence of colorectal polyps with laterally spreading tumors (LSTs) is commonly observed during colonoscopy. However, there are rare studies that assess the malignant risks for LSTs with colorectal polyps, which might largely contribute to further strategies of treatment and follow-up plans in LSTs. Methods We conducted a retrospective cohort study that enrolled 206 patients with LSTs in the Endoscopy Center and Endoscopy Research Institute, Renji Hospital, Shanghai Jiao Tong University, China. The subjects with LSTs were divided into two groups: the nonpolyp group with 89 patients and the polyp group with 117 patients. Binary logistic regression was used to identify the independent predictors of outcomes of interest. Results The risk of the polyps' coexistence phenomenon increased in males compared with females (OR = 2.138, p = 0.047), especially in those between 50 and 75 years old (OR = 7.074, p = 0.036). Tumor size (3–4 cm), LSTs with tubulovillous types, and history of polyps statistically increased the risk of the polyp coexistence phenomenon (OR = 5.768, p = 0.003; OR = 36.345, p = 0.024; OR = 13.245, p < 0.0001, respectively). LST-NG-PD (OR = 20.982, p = 0.017) and LSTs ≥ 5 cm (OR = 37.604, p = 0.038) notably increased the malignant risk of LSTs. When the simultaneous polyps are located in the right colon, the risk of malignant LSTs (OR = 58.540, p = 0.013) positively increased. Conclusion The simultaneous colorectal polyps in the right colon were the most important risk factor to predict the malignant risk of LSTs.

A patient with colitis-associated cancer who developed clinically manifest Crohn\u2019s disease only after surgery

BackgroundPatients with prolonged inflammatory bowel disease have a greater risk of colorectal cancer, known as colitis-associated cancer. Here we describe an unusual case of colitis-associated cancer.Case presentationThe subject is a 41-year-old male who has not presented digestive symptoms and has an appreciable medical history. He consulted a nearby doctor with left flank pain. A colonoscopy revealed a lateral spreading tumor (granular-type) in his descending colon. With a clinical diagnosis of cancer, D3 left hemicolectomy was performed and a small intestine stoma was constructed. The pathological diagnosis of the tumor was mucinous adenocarcinoma, pT4a(SE), pN2a, which was associated with dysplasia in the surface area. Post-operative ileus was prolonged and the endoscopic examination revealed longitudinal ulcers in the ileum. These ulcers responded quite well to the administration of infliximab, confirming the final diagnosis of Crohn’s disease. Pathological re-examination revealed that the tumor was dysplasia-associated type, and another dysplasia was confirmed near the tumor. Furthermore, mural scars and sporadic lymphoid aggregates were noted in the colon tissues, which suggested pre-existing Crohn’s disease. The patient died of peritoneal dissemination of cancer on day 207 after surgery.ConclusionThe present case was diagnosed as colitis-associated cancer with clinically latent Crohn’s disease, who developed clinically manifest Crohn’s disease only after surgery. Our review of literature revealed no cases comparable to ours.

Long-term outcomes of endoscopic treatment for colorectal laterally spreading tumor: a large-scale multicenter retrospective study from China

Laterally spreading tumor (LST) is a type of precancerous lesion of colorectal cancer with high malignant potential. The present study aimed to evaluate long-term outcomes of endoscopic treatment for LST in Chinese patients. This study was a retrospective review of data collected from 653 included patients with LST from six regional representative hospitals in China between January 2007 and January 2017. Demographic characteristics, endoscopic features of LST, operation-related data, and follow-up results were collected and analyzed. LST-granular type (LST-G, 80.3%) was much more common than LST-non-grandular type (LST-NG, 19.7%). The overall submucosal invasion rate of all LSTs was 6.1% and the submucosal invasion rate of LST-NG was significantly higher than that of LST-G (6.79% vs. 3.87%, p = 0.000). The en bloc resection rate of ESD and EMR treatment was 96% and 93.7%, respectively, with pathologic R0 resection rate of 90.1% and 82.8%. After an average duration of follow-up about 34.52 ± 11.76months, the recurrence rate of ESD was 3.47%, and the recurrence rate of EMR was 8.8% after an average follow-up of about 38.44 ± 4.42months. However, the recurrence rate of ESD was much lower than piecemeal EMR for LST (3.47% vs. 8.62%, p = 0.017). Retroflexion-assisted technique applied for resection of rectal LST was associated with a significantly shortened operating time (85.40min vs. 174.18min, p = 0.002). Endoscopic resection is a safe and efficient modality for the treatment of colorectal LST with a relatively low recurrence rate and shortened operating time with the use of retroflexion.

Cap-fitted endoscopic mucosal resection of ≥ 20 mm colon flat lesions followed by argon plasma coagulation results in a low adenoma recurrence rate.

Background and study aims Endoscopic mucosal resection (EMR) is increasingly used for the treatment of large colonic polyps (≥ 20 mm). A drawback of EMR is local adenoma recurrence. Therefore, we studied the impact of argon plasma coagulation (APC) of the EMR edge on local adenoma recurrence. Patients and methods This was a retrospective study of patients with laterally spreading tumors (LST) ≥ 20 mm, who underwent EMR from January 2009 to August 2018 and follow-up endoscopic assessment. A cap-fitted endoscope was used to assess completeness of resection by systematically inspecting the EMR defect for any macroscopic disease. This was followed by forced APC of the resection edge followed by clip closure of the defect. Surveillance colonoscopy was performed at 6 months after resection to detect recurrence. Results Two hundred forty-six patients met the inclusion criteria. Most were female (53 %) and white (80 %), with a Median age of 64 years. Median polyp size was 35 mm (interquartile range, 30–45 mm). Most polyps were located in the right colon (77 %) and were removed by piecemeal EMR (70 %). Eleven patients (5 %) had residual tumor at the resection site. Conclusions We observed low adenoma recurrence after argon plasma coagulation of the EMR edge with a cap fitted colonoscope in patients with LST ≥ 20 mm of the colon, which requires further validation in a randomized controlled study.

Endoscopic mucosal resection versus endoscopic submucosal dissection for colorectal laterally spreading tumors: a meta-analysis

To assess the efficacy and safety of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) in the treatment of colorectal laterally spreading tumors (LSTs). A systematic literature search was performed in Pubmed, Embase, the Cochrane Library, CNKI and WANFANG databases. The related literatures were selected according to certain inclusion and exclusion criteria. The Cochrane Collaboration's Revman 5.3 software was used for data analysis. A total of 12 studies were included in the analysis. The total number of lesions was 3062 (EMR: 1906; ESD: 1156). The en bloc resection rate of ESD was 95% (1098/1156), which was significantly higher than that of EMR (42.8%, 815/1906) [OR=0.07, 95% CI (0.02, 0.07), P<0.00001]. The complete resection rate of ESD was 93.2% (109/117), which was significantly higher than that of EMR as well (71.9%, 92/128) [OR=0.12，95% CI (0.05, 0.29), P<0.00001]. The bleeding rate showed no significant difference between EMR and ESD (4.2% vs. 3.5%) [OR=1.04, 95% CI (0.68, 1.60), P=0.85]. The perforation rates of EMR and ESD were 1.8% and 2.4%, respectively, which displayed significant difference [OR=0.56, 95% CI (0.32,0.97), P=0.04]. Nevertheless, the recurrence rate of EMR was significantly higher than that of ESD (15.9% vs. 0.5%) [OR=23.06, 95% CI (11.11, 47.85), P<0.00001]. Endoscopic resection of LSTs is safe and effective. As compared with EMR, ESD has higher en-bloc and complete resection rates but a lower recurrence rate. Therefore, ESD is highly recommended for treatment of LSTs.

Evaluation of recurrence and surgical complementation rates after endoscopic resection of large colorectal non-pedunculated lesions.

the process that leads to the development of colorectal cancer takes many years and most tumors originate from polyps and non-polypoid lesions. Techniques of endoscopic resection are surgical treatment options, even in case of large lesions or with initial invasion. This study aimed to evaluate the recurrence and surgical complementation rates after endoscopic resection of large colorectal non-pedunculated lesions. a retrospective, longitudinal and descriptive trial was performed via an analysis of colonoscopies with the resection of non-pedunculated lesions larger than 3 cm, performed between 2014 and 2017. sixty-two lesions were included from 61 patients and 32 (52.5 %) were female. The age ranged from 36 to 89 years, with a mean age of 60.5 years. Lesions had an average diameter of 40.08 mm, ranging from 30 to 80 mm. Regarding the location of the lesions, the most frequent colonic segments were the ascending and rectum, both accounting for 22.6 %. Considering the morphologic endoscopic classification, 67.7 % were granular laterally spreading tumors (LST), 38.8 % were homogeneous granular and 29 % were mixed granular. The most frequent histological types were tubulovillous adenoma (30.7 %) and intramucosal adenocarcinoma (29 %). The resection technique was piecemeal mucosectomy in 85.5 %. Five lesions were removed by en bloc mucosectomy, two (3.2 %) by endoscopic submucosal dissection (ESD) and two (3.2 %) by a hybrid technique. The recurrence rate was 25.8 %. Three patients needed complementary surgical treatment and the clinical success of endoscopic treatment was 95.1 %. recurrence rate after endoscopic resection of large colorectal lesions was 25.8 % and surgical complementation rate due to failure in the endoscopic treatment of recurrence was 4.8 %.

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.

Comparison of the histopathological characteristics of large colorectal laterally spreading tumors according to growth pattern.

Objectives: Colorectal laterally spreading tumors (LSTs) are widely recognized owing to their structural characteristics. This study aims to clarify the histopathological characteristics of large colorectal LSTs according to growth pattern. Methods: We studied 297 colorectal LSTs measuring ≥20 mm in diameter. The LSTs were classified into four types: granular homogenous type (LST-G-H), granular nodular mixed type (LST-G-M), non-granular flat elevated type (LST-NG-F), and non-granular pseudo-depressed type (LST-NG-PD). Retrospectively collected data were examined to compare the histopathological characteristics of LSTs according to the growth pattern. Results: LST-G-M lesions (142 lesions) were most common, followed by LST-NG-F (74 lesions), LST-G-H (61 lesions), and LST-NG-PD (20 lesions). The mean tumor diameter of LST-G lesions (38.5 ± 17.2 mm) was significantly greater than that of LST-NG lesions (26.3 ± 7.0 mm, P < 0.001). In particular, 45% of LST-G-M lesions were ≥40 mm in diameter. Adenomas accounted for 54% of LST-G-H lesions compared with only 10% of LST-NG-PD lesions. Pathological T1 carcinomas accounted for 55% of LST-NG-PD lesions and were not found among LST-G-H lesions. Conclusions: The biological malignancy of colorectal LSTs differs considerably depending on the growth pattern even among large lesions and therefore should be considered when selecting treatment regimens.

Diagnostic value of JNET classification under narrow-band imaging for colorectal laterally spreading tumors

Objective To evaluate the diagnostic efficacy of Japan Narrow Band Imaging Expert Team(JNET) classification under narrow-band imaging (NBI) for colorectal laterally spreading tumors. Methods Data of 170 laterally spreading tumors (LST) detected by NBI and pigment dyeing were reviewed in the retrospective study. JNET classification under NBI was used for rediagnosis based on surface pattern and vessel pattern. Pit pattern(PP) was observed under pigment dyeing using PP classification. The results were compared with histologic results after endoscopic resection or surgery. Results The diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of JNET classification and PP classification were 92.2% VS 70.3%, 82.3% VS 85.0%, 74.7% VS 72.6%, 94.9% VS 83.5%, 85.9% VS 79.7%, respectively (P=0.159). The consistency rates of JNET classification and PP classification in predicting shallow invasion depth of LST were 6.1% and 8.3% respectively and the consistency rates in predicting deep invasion were 30.8% and 4.8%, respectively. Conclusion JNET classification under NBI is effective in predicting malignant laterally spreading tumors, however, its efficacy in predicting tumor invasion depth is unsatisfied. PP classification can be used to improve the diagnostic accuracy for those with diagnostic difficulty. Key words: Colorectal neoplasms; Diagnosis; Laterally spreading tumor; Narrow-band imaging; JNET classification

Long-term outcomes of endoscopically resected laterally spreading tumors with a positive histological lateral margin.

With advances in diagnostic endoscopy, the incidence of superficial colorectal tumors, including laterally spreading tumors (LSTs), has increased. However, little is known about the long-term results of LSTs with positive lateral margin after endoscopic treatment. This study aimed to evaluate the long-term clinical outcomes and risk factors for local recurrence of LSTs with positive lateral margin after initial endoscopic resection. We performed a retrospective analysis of the medical records of 324 patients who had 363 LSTs with positive lateral margin after endoscopic resection at a tertiary academic medical center. The medical records from 2011 to 2015 were analyzed. Local recurrence was confirmed through endoscopic finding and subsequent biopsy analysis. We assessed the local recurrence rate and performed multivariate analyses to identify the factors associated with local recurrence. Follow-up colonoscopy was performed in 176 of 363 LSTs. The local recurrence rate was 6.3% (11/176), with a median (interquartile range [IQR]) follow-up period of 19.8 (12.4-46.5) months. In multivariate analysis, local recurrence was associated with piecemeal resection (odds ratio [OR] 6.62, 95% confidence interval [CI] 1.28-34.33; p = 0.024) and inversely associated with thermal ablation (OR 0.033, 95% CI 0.00-0.45; p = 0.011). At surveillance colonoscopy, histology of the recurrent tumor was adenoma in 10 (90.9%) of 11; these were treated endoscopically. In this retrospective study, we found that endoscopically resected LSTs with positive lateral margin have a low recurrence rate. Piecemeal resection was associated with higher local recurrence, and thermal ablation was inversely associated with local recurrence. Endoscopic resection with positive lateral margin combined with thermal ablation leads to a low recurrence rate.

Endoskopische Abtragung eines vernarbten Adenoms im Rektum mittels EndoRotor

Benign colorectal neoplasia are commonly resected using snare resection or endoscopic submucosal dissection (ESD). These methods are safe, but just the piecemeal resection in flat adenomas greater than 20 mm harbor a relevant risk of recurrence. Interventional endoscopic therapy of recurrent lesions can be challenging, even in expert hands due to a high risk of complications. While smaller, scarred recurrent adenomas less than 20 mm are suitable for endoscopic full-thickness resection, hitherto larger ones have had to be removed with more laborious, time-consuming and costly endoscopic methods, or had to undergo surgery. The EndoRotor is a novel non-diathermic resection system for benign neoplasia in the gastrointestinal tract. The tissue is aspirated into an opening at the tip of a flexible resection catheter, dissected by means of a rotating blade on the inside of the catheter and finally transported into a tissue trap. We present the case of a 79-year-old female patient with a large recurrent adenoma of a lateral-spreading tumor granular type in the rectum. Whereas a part of the adenoma could be resected with ESD, the scarred parts were not amenable to traditional endoscopic methods. By using EndoRotor, the scarred adenoma could be resected completely and without any complication. Scarred adenomas pose a challenge for interventional endoscopy. In this case study, EndoRotor proved to be a safe and viable method and a new resection option for complicated scarred rectal adenomas.

INCREASED RISK OF SYNCHRONOUS COLORECTAL LESIONS IN PATIENTS REFERRED FOR ENDOSCOPIC MUCOSAL RESECTION OF LATERAL SPREADING TUMORS.

Endoscopic mucosal resection is one of the most frequent therapeutic alternatives for large colorectal lateral spreading tumors. There are few data on the prevalence of synchronous lesions on these patients. To describe the prevalence of synchronous colorectal lesions in patients referred for endoscopic mucosal resection of lateral spreading tumors >20 mm. We reviewed the endoscopic database of our Department and identified adult patients who were referred for the resection of a colorectal lateral spreading tumor >20 mm and had a diagnostic colonoscopy performed up to six months before. The proportion of patients with at least one synchronous lesion was estimated. The following features were compared between patients with and without synchronous lesions: age, gender, bowel preparation quality and cecal intubation on index colonoscopy and therapeutic colonoscopy, serrated adenoma as index lesion. From December 2016 to November 2017, we identified 70 patients who fulfilled inclusion criteria. Median size of lesions was 25 mm (20-45). Eighty percent were located in the right colon and 35.71% were serrated adenomas. Synchronous lesion rate was 38.57%. Bowel preparation quality was similar in both groups when comparing both index and therapeutic colonoscopies. Patients with synchronous lesions had a higher proportion of serrated adenoma as index lesion than patients without synchronous lesions [51.85% vs 25.58%, OR 3.13 (1.13-8.68), P=0.03]. We found a high prevalence of synchronous lesions among patients with a large colorectal lateral spreading tumor. This risk seems to be increased if index lesions are serrated adenomas.

Wide-field underwater EMR followed by line-assisted complete closure for a large duodenal adenoma.

Wide-field underwater EMR followed by line-assisted complete closure for a large duodenal adenoma.

A clinical study of preoperative endoscopic assessment of the invasion depth of colorectal laterally spreading tumor

Objective To compare the diagnostic accuracy of magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) for preoperative endoscopic assessment of the invasion depth of colorectal laterally spreading tumour(LST). Methods Data of 104 cases of colorectal LST were included. With the final pathological diagnosis as the golden standard, the accuracies of MCE and EUS for preoperative assessment of the invasion depth of colorectal LST were compared. Results The diagnostic accuracies of MCE and EUS for evaluating the invasion depth of LST were 89.4%(93/104) and 73.1%(76/104), respectively(P<0.05). The lesion size and the endoscopist could affect the accuracy of the EUS evaluation(P=0.017, OR=3.561; P=0.035, OR=1.399). The accuracy of EUS seemed to show a downward trend for colorectal LST of larger diameters. Conclusion Both MCE and EUS are effective for evaluating the invasion depth of colorectal LST, but the accuracy of MCE may be higher than that of EUS. Large diameter of the lesion and the doctor's experience inadequacy may be the risk factors for the accuracy of EUS. Key words: Colorectal neoplasms; Endosonography; Program evaluation; Laterally spreading tumor; Magnifying chromoendoscopy