Laterally Spreading Tumors Research Articles

Cost-effectiveness analysis of endoscopic resection for colorectal laterally spreading tumors: Endoscopic submucosal dissection versus piecemeal endoscopic mucosal resection.

The cost-effectiveness of endoscopic submucosal dissection (ESD) and piecemeal endoscopic mucosal resection (pEMR) for colorectal laterally spreading tumors (LSTs) remains unclear. We examined the cost-effectiveness of these procedures for cases of colon/rectal LST-non-granular-type ≥2 cm and LST-granular-mixed-type ≥3 cm. We performed a simulation model analysis using parameters based on clinical data from the National Cancer Center Hospital, Tokyo, and previous literature. The number of recurrences and surgeries and the required costs for 5 years following ESD and pEMR were assessed. Japanese cost data were used in the base-case analysis, and probabilistic sensitivity analysis (PSA) was performed. The Swedish cost data were used in the scenario analysis. Endoscopic submucosal dissection yielded a considerably lower number of recurrences and surgeries but required a higher cost than pEMR. The recurrence rates following ESD and pEMR were 0.9-1.3% and 21.1-25.9%, respectively. The incremental cost-effectiveness ratios for an avoided recurrence and surgery for ESD against pEMR were 376,796-476,496 JPY (3575-4521 USD) and 7,335,436-8,187,476 JPY (69,604-77,689 USD), respectively. PSA demonstrated that the probability of ESD being chosen as a more cost-effective option than pEMR was >50% at willingness-to-pay values of ≥400,000-500,000 JPY (3795-4744 USD) for avoiding a recurrence and ≥9,500,000-10,500,000 JPY (90,143-99,631 USD) for avoiding a surgery. In the scenario analysis, the required cost was also lower for ESD. Our findings suggest potentially favorable cost-effectiveness of ESD, depending on cost settings and the willingness-to-pay value for avoiding recurrence/surgery.

How to trick artificial intelligence: rectal heterotopic gastric lateral spreading tumor.

Video 1.

Novel approaches to minimize intraoperative bleeding during endoscopic submucosal dissection of a large rectal lateral spreading tumor extended to the dentate line with internal hemorrhoids.

Video 1Endoscopic submucosal dissection (ESD) of large rectal lateral spreading tumors (LSTs) that extend to the dentate line with internal hemorrhoids is a challenging procedure because of the increased risk of bleeding from penetrating and hemorrhoidal vessels and the reduced visual field caused by the dilated venous packages and the narrow anal lumen.This video describes novel technical approaches to minimize the risk of intraoperative bleeding.The described approaches are indicated in large rectal LSTs that extend to the dentate line with large internal hemorrhoids. The described selective-vessel approach is also indicated in any vascularized superficial lesion amenable to endoscopic treatment.ESD was performed in the retroflex view using an Evis Exera II video processor, an H180 gastroscope, an ERBE ICC 200, and CO2 insufflation. As tools, IT-nano, needle knife, hook knife, hemostatic forceps, and a distal cap were used. The lifting solution was a mixture of normal saline, hyaluronic acid, epinephrine, and indigo carmine.A hemicircumferential superficial granular lateral spreading tumor was observed in the lower rectum. Indigo carmine dye spray facilitated the identification of the lesion's margin and demonstrated no ulcer, converging folds, or large nodules. After the submucosal (SM) injection, a shallow mucosal incision was made in the retroflex view using a conventional needle knife, followed by the circumferential incision at the proximal side using an IT-nano. The SM layer was dissected at a superficial level to avoid large SM vessels, thus preventing intraoperative bleeding and maintaining a clean surgical field. Small vessels were selectively coagulated mainly by using the small disc located at the back of the insulated tip as the SM later was superficially dissected. To facilitate precise coagulation, a stepwise dissection technique was used for larger vessels. After identification, the vessel was first exposed by dissecting the surrounding SM layer at the left and right sides using the long blade of IT-nano, with blunt dissection of the surrounding tissue at the vessels' posterior aspect using a Hook knife. Double-vessel sealing using a hemostatic forceps was performed both at the rectal and tumor sides. Lastly, the vessel was transected between sealed segments using the IT-nano, without major bleeding. The circumferential incision was completed at the left side and distally extended to the anal canal where large hemorrhoidal bundles were seen. A needle knife was used to complete the SM dissection and, here, the final cut. En bloc resection was successfully achieved without intraoperative bleeding.The en bloc resected specimen was 85mm in size, and squamous epithelium of the anal canal was observed at the distal margin. Colonoscopy 5 months post-ESD revealed adequate healing, no stenosis and no hemorrhoids.Coagulation and hemostasia should be promptly carried out whenever inadvertent injury to large vessels and subsequent bleeding occurs during lateral exposure, posterior blunt dissection, double coagulation, and transection of vessels.Curative ESD can be achieved in large rectal LSTs that extend to the dentate line with large internal hemorrhoids. Strategies to minimize intraoperative bleeding during ESD should be considered and include the following:•An SM dissection from the proximal tumor margin in the retroflex view to circumvent contact with hemorrhoids.•A differential level of dissection to prevent inadvertent vessel injury-shallow first to avoid large SM vessels and deeper above the muscular layer closer to the dentate line to shut off blood supply by penetrating hemorrhoidal vessels.•Last but not least, a selective approach to vessels to reduce the risk of bleeding, with direct coagulation for small vessels and with lateral exposure, posterior blunt dissection, double-vessel sealing, and transection between sealed segments for larger vessels.

Fecal Enterotoxigenic Bacteroides fragilis-Peptostreptococcus stomatis-Parvimonas micra Biomarker for Noninvasive Diagnosis and Prognosis of Colorectal Laterally Spreading Tumor.

ObjectiveUp to now, non-invasive diagnosis of laterally spreading tumor (LST) and prediction of adenoma recurrence after endoscopic resection of LSTs is inevitable. This study aimed to identify a microbial signature with clinical significance of diagnosing LSTs and predicting adenoma recurrence after LSTs colectomy.MethodsWe performed 16S rRNA sequencing in 24 mucosal samples, including 5 healthy controls (HC), 8 colorectal adenoma (CRA) patients, and 11 LST patients. The differentiating microbiota in fecal samples was quantified by qPCR in 475 cases with 113 HC, 208 CRA patients, 109 LST patients, and 45 colorectal cancer (CRC) patients. We identified differentially abundant taxa among cases and controls using linear discriminant analysis effect size analysis. ROC curve was used to evaluate diagnostic values of the bacterial candidates. Pairwise comparison of AUCs was performed by using the Delong’s test. The Mantel-Haenszel hazard models were performed to determine the effects of microbial compositions on recurrence free survival.ResultsThe microbial dysbiosis of LST was characterized by relative high abundance of the genus Lactobacillus-Streptococcus and the species enterotoxigenic Bacteroides fragilis (ETBF)–Peptostreptococcus stomatis (P. stomatis)–Parvimonas micra (P. micra). The abundance of ETBF, P. stomatis, and P. micra were steadily increasing in LST and CRC groups. P. stomatis behaved stronger value on diagnosing LST than the other two bacteria (AUC 0.887, 95% CI 0.842–0.931). The combination of P. stomatis, P. micra, and ETBF (AUC 0.922, 95% CI 0.887–0.958) revealed strongest diagnostic power with 88.7% sensitivity and 81.4% specificity. ETBF, P. stomatis, and P. micra were associated with malignant LST (PP.stomatis = 0.0015, PP.micra = 0.0255, PETBF = 0.0169) and the abundance of IL-6. The high abundance of P. stomatis was related to the adenoma recurrence after LST resection (HR = 3.88, P = 0.008).ConclusionsFecal microbiome signature (ETBF–P. stomatis–P. micra) can diagnose LSTs with high accuracy. ETBF, P. stomatis, and P. micra were related to malignant LST and P. stomatis exhibited high predictive value on the adenoma recurrence after resection of LSTs. The fecal microbiome signature of LST may provide a noninvasive alternative to early detect LST and predict the adenoma recurrence risk after resections of LSTs.

Hybrid endoscopic submucosal dissection: An alternative resection modality for large laterally spreading tumors in the cecum?

BackgroundEndoscopic resection for large, laterally spreading tumors (LSTs) in the cecum is challenging. Here we report on the clinical outcomes of hybrid endoscopic submucosal dissection (ESD) in large cecal LSTs.MethodsWe retrospectively reviewed data from patients with cecal LSTs ≥ 2 cm who underwent ESD or hybrid ESD procedures between January of 2008 and June of 2019. We compared the baseline characteristics and clinical outcomes, including procedure time, the en bloc and complete resection rates, and adverse events.ResultsA total of 62 patients were enrolled in the study. There were 27 patients in the ESD group and 35 patients in the hybrid ESD group, respectively. Hybrid ESD was more used for lesions with submucosal fibrosis. No other significant differences were found in patient characteristics between the two groups. The hybrid ESD group had a significantly shorter procedure time compared with the ESD group (27.60 ± 17.21 vs. 52.63 ± 44.202 min, P = 0.001). The en bloc resection rate (77.1% vs. 81.5%, P = 0.677) and complete resection rate (71.4% vs. 81.5%, P = 0.359) of hybrid ESD were relatively lower than that of the ESD group in despite of no significant difference was found. The perforation and post-procedure bleeding rate (2.9% vs. 3.7%, P = 0.684) were similar between the two groups. One patient perforated during the ESD procedure, which was surgically treated. One patient in the hybrid ESD group experienced post-procedure bleeding, which was successfully treated with endoscopic hemostasis. Post-procedural fever and abdominal pain occurred in six patients in the ESD group and five patients in the hybrid ESD group. One patient in the ESD group experienced recurrence, which was endoscopically resected.ConclusionThe results of this study indicate that hybrid ESD may be an alternative resection strategy for large cecal LSTs with submucosal fibrosis.

The number of biopsy specimens can influence the non-lifting sign incolorectal laterally spreading tumors.

Although the problem of whether to perform a biopsy before endoscopic treatment for colorectal laterally spreading tumor (LST) troubles clinicians, about 50 % of lesions still undergo a preceding biopsy. We aimed to explore factors affecting the non-lifting sign in LST and examine the influence of "biopsy-related factors", such as the number of biopsy specimens and the interval after biopsy on non-lifting sign in cases with a history of biopsy. Clinical data of 159 LSTs regarding age, gender, history of biopsy, tumor location, tumor size, the depth of submucosal invasion, tumor configuration, histologic type, location with respect to the fold, and result of non-lifting sign testing were investigated retrospectively. For patients with a history of biopsy, the period after biopsy and the number of biopsy specimens also were analyzed. Among 159 cases of LST, 112 were positive and 47were negative for lifting signs. Biopsy history (p = 0.008), tumor size (p = 0.010), and location with respect to the fold (p = 0.022) were identified as factors affecting the non-lifting sign in multivariate analyses. In 75 LST cases with a history of biopsy, only the number of biopsies (p = 0.003) was identified as a factor affecting the non-lifting sign in multivariate analyses. For LST, lesions with larger size, being across the fold, and biopsy history were predictive factors for non-lifting signs. Reducing the number of biopsies would reduce the occurrence of non-lifting signs when biopsy is necessary. The impact of the interval after the biopsy on the non-lifting sign will require further study.

Resección de adenoma velloso gigante causante del síndrome de Mckittrick-Wheelock

Large colorectal villous adenomas are unusual. They can cause a rectal bleeding, a chronic diarrhea and less frequently a rectal obstruction and a prolapse. In addition, they can secrete a mucinous material rich in electrolytes, causing hydroelectrolyte disturbances, dehydration and acute kidney injury. In most cases, the management of these adenomas due to their size has been surgical, but endoscopic treatment has been reported with promising results, reducing the morbidity. We report and discuss the case of a 73-year-old man, who presented with syncope, with chronic diarrhea and a hydroelectrolytic alteration. Colonoscopy revealed a granular lateral spreading tumor of the rectum, and pathology confirmed a villous adenoma with a low-grade dysplasia. An initial symptomatic management of diarrhea and electrolyte disorders was performed with a subsequent surgical treatment using pull through technique with coloanal anastomosis.

Utility of under-gel endoscopic mucosal resection with partial submucosal injection for a laterally spreading tumor.

Conventional endoscopic mucosal resection (EMR) is a widely used technique in the treatment of colorectal tumors. When resecting laterally spreading tumors (LSTs) with conventional EMR, the distal edge is difficult to dissect and tends to be piecemealed. However, the nongranular pseudodepressed type (LST-NG-PD) has a high risk of malignancy, requiring en bloc resection [1]. Endoscopic submucosal dissection (ESD) can ensure high en bloc resection rates, but it also has drawbacks such as high perforation rates, high cost, and long procedure times. Binmoeller et al. introduced underwater EMR (UEMR) as a useful alternative to ESD for LSTs [2]; however, treating the distal end remains a challenge and could cause segmental resection. In addition, the use of water in UEMR may impair clarity of view if bleeding occurs. Partial submucosal injection improves visualization of the distal edge [3], and gel immersion improves the endoscopic visual field [4] [5]. Here, we report that under-gel EMR with partial submucosal injection is an effective means of achieving en bloc resection of LST-NG-PD ([Video 1]).

Interobserver agreement of the Paris and simplified classifications of superficial colonic lesions: a Western study.

Background and study aims The Paris classification of superficial colonic lesions has been widely adopted, but a simplified description that subgroups the shape into pedunculated, sessile/flat and depressed lesions has been proposed recently. The aim of this study was to evaluate the accuracy and inter-rater agreement among 13 Western endoscopists for the two classification systems. Methods Seventy video clips of superficial colonic lesions were classified according to the two classifications, and their size estimated. The interobserver agreement for each classification was assessed using both Cohen k and AC1 statistics. Accuracy was taken as the concordance between the standard morphology definition and that made by participants. Sensitivity analyses investigated agreement between trainees (T) and staff members (SM), simple or mixed lesions, distinct lesion phenotypes, and for laterally spreading tumors (LSTs). Results Overall, the interobserver agreement for the Paris classification was substantial (κ = 0.61; AC1 = 0.66), with 79.3 % accuracy. Between SM and T, the values were superimposable. For size estimation, the agreement was 0.48 by the κ-value, and 0.50 by AC1. For single or mixed lesions, κ-values were 0.60 and 0.43, respectively; corresponding AC1 values were 0.68 and 0.57. Evaluating the several different polyp subtypes separately, agreement differed significantly when analyzed by the k-statistics (0.08–0.12) or the AC1 statistics (0.59–0.71). Analyses of LSTs provided a κ-value of 0.50 and an AC1 score of 0.62, with 77.6 % accuracy. The simplified classification outperformed the Paris classification: κ = 0.68, AC1 = 0.82, accuracy = 91.6 %. Conclusions Agreement is often measured with Cohen’s κ, but we documented higher levels of agreement when analyzed with the AC1 statistic. The level of agreement was substantial for the Paris classification, and almost perfect for the simplified system.

Pathological Analysis and Endoscopic Characteristics of Colorectal Laterally Spreading Tumors.

ObjectiveThis study aims to analyze the endoscopic and pathological characteristics of colorectal laterally spreading tumors (LSTs) to assist malignant risk stratification to inform selection of the appropriate treatment strategy.MethodsPatients with colorectal LST were selected as retrospective study objects. Characteristics, including endoscopic findings and the most common site of LSTs of different diameters and histological types, were analyzed. The risk factors for malignancy in colorectal LST were explored by multivariate logistic regression analysis.ResultsLSTs with diameters of ≥20 mm were found mainly in the rectum and mainly with granular-mixed (G-M) morphology (36% and 44.6%, respectively; p < 0.05), while LSTs with diameters of <20 mm were found mainly in the ascending colon and mainly with granular-homogenous (G-H) morphology (40.9% and 46.2%, respectively; p < 0.05). Adenoma was the main histological type in patients with tumors of all diameters. However, the cancerization rate of LSTs was 31% in patients with tumor diameter ≥20 mm, while there was no invasive cancer in patients with tumor diameter < 20 mm. In the low-grade dysphasia (adenoma) group, most of the lesions were located in the ascending colon and most had the morphology LST-G-H (35.8% and 39.2%, respectively; p < 0.05). In the cancerization group, most of the lesions were located in the rectum, with the morphology LST-G-M (51.6% and 67.2%, respectively; p < 0.05), and the diameter was larger than that of the adenoma group (33.84 ± 17.99 mm vs 21.68 ± 8.99 mm).ConclusionThe rectum was the most common site for an LST with a diameter ≥20 mm and cancerization, of which the morphology was mainly LST-G-M (endoscopic submucosal dissection is the preferred treatment for this type of LST). LST malignancy was found to be correlated with lesion diameter, location, and morphological appearance.

Endoscopic submucosal dissection for rectal-sigmoid laterally spreading tumors ≥10 cm: an analysis of 10 cases.

BackgroundEndoscopic submucosal dissection (ESD) is a standard method for treating selected colorectal laterally spreading tumors (LSTs). However, technical difficulty occurs with the increase in tumor size, and little is known about the efficacy of ESD treatment in colorectal LSTs ≥10 cm. The present study aimed to report the feasibility, safety, and efficacy of ESD for rectal-sigmoid LSTs ≥10 cm.MethodsFrom May 2012 to December 2019, patients with rectal-sigmoid LSTs ≥10 cm and underwent colorectal ESD were enrolled retrospectively. Demographic features, procedure-related parameters (procedure time, adverse events, rate of en bloc resection and complete resection), and follow-up results were recorded and analyzed.ResultsA total of 10 patients successfully underwent ESD: nine patients received conventional ESD, while the other one underwent tunneling ESD. The median diameter of the LSTs was 11.5 cm, and the median procedure time was 210 minutes. The rates of en bloc and curative resection rates were 100% and 90%, respectively. Of the ten patients, four had developed adverse events, one had intraoperative bleeding, two patients had delayed bleeding, and the other one had postoperative fever and rectum stricture postoperatively. None of the patients experienced recurrence during a median follow-up of 62 months.ConclusionsESD can be used as a feasible, safe and effective treatment modality for the management of rectal-sigmoid LSTs ≥10 cm.

Endoscopic mucosal resection of large colonic laterally spreading tumors using a dedicated viscous solution for submucosal injection (ORISE gel): a short case series (with video).

Endoscopic mucosal resection (EMR) of large (>20 mm) laterally spreading tumors (LSTs) was usually rescheduled to guarantee experienced operator and enough endoscopic schedule time. The use of viscous solutions allows a reduction in repeated injections, snare resections and procedural time. The aim was to describe the outcome of EMR of large LSTs performed at the time of index colonoscopy, using ORISE gel (Boston Scientific). A retrospective analysis was performed retrieving patients who underwent EMR of large colonic LSTs at the time of index colonoscopy. EMR was performed after dynamic injection of ORISE gel to create a submucosal cushion. Procedural parameters, together with pathological and endoscopic outcomes, were analyzed. Five patients [three males, median age 65 (45-70) years] were included. Median LST size was 35 mm (25-40). Median procedure time was 8 min (range 3-13). En bloc resection was achieved in one out of five cases; four out of five were planned as piecemeal resections. A median of 10 mL (10-20) of viscous solution was injected. R0 resection was achieved in the single case who underwent en bloc EMR, whereas it was not assessable in the case of piecemeal resections. One self-limiting bleeding was observed. The use of ORISE gel allows a well-tolerated and rapid performance of EMR of large colonic LSTs even at the time of index colonoscopy. In our opinion, in these specific situations, the use of viscous solutions is advisable and also affordable.

Effectiveness and risk factors of endoscopic submucosal dissection for right colon neoplasms

Introduction. Endoscopic submucosal dissection (ESD) is a standard method of local excision of benign colon tumors. Nevertheless, it is not widely used because of its technical difficulty and risk of complication especially in right colon. The OBJECTIVE was to improve the results of treatment of patients with right colon neoplasms.Methods and materials. The results of 152 consecutive patients (median age 66 years, 88 female) with lateral spreading tumors (LST) were analyzed. Logistic regression was performed to evaluate risk factors of conversion and complications.Results. ESD as planned performed in 133 out of 152 patients. Conversion to bowel resection occurred in 19 cases. In the logistic regression model, lifting less than 3 mm (p=0.034) was independent risk factor of the conversion. Postoperative complications up to 30 days occurred in 5 out of 133 (3.8 %) of patients underwent ESD. There was no mortality after ESD. Severe fibrosis the base of the neoplasm was the only risk factor of postoperative complications (95 % CI=1.0—1.2; p=0.007). Final pathology revealed that 127 out of 133 patients (95.5 %) had adenomas and 6 out of 133 (4.5 %) patients had early adenocarcinomas. R0 resections was performed in 94/133 (70.7 %) cases.Conclusions. ESD is the safe and efficient method of local excision of benign right colon neoplasms. Unfavorable lifting (p=0.05) and submucosal fibrosis (p=0.007) are risk factors of ESD failure.

Endoscopic Recognition and Management Strategies for Malignant Colorectal Polyps: Recommendations of the US Multi-Society Task Force on Colorectal Cancer.

Endoscopic Recognition and Management Strategies for Malignant Colorectal Polyps: Recommendations of the US Multi-Society Task Force on Colorectal Cancer.

Artificial intelligence for non-polypoid colorectal neoplasms.

The miss rate of flat advanced colorectal neoplasia is still unacceptably high, especially in the Western setting, notwithstanding the widespread implementation of quality improvement programs and training. It is well known that flat morphology is associated with miss rate of colorectal neoplasia, and that this subset of lesions often shows a more aggressive biological behaviour. Artificial intelligence (AI) applied to the detection of colorectal neoplasia has been shown to increase adenoma detection rate, consistently across all lesion sizes and locations in the colon. However, there is still uncertainty whether AI can reduce the miss rate of flat advanced neoplasia, mainly because all published trials report a low number of flat colorectal lesions in their training sets, and this could reduce AI accuracy for this subset of lesions. In addition, flat lesions have different morphologies with variable prevalence and potentially different accuracy in their detection. For example, the subtle appearance and rarer frequency of a non-granular laterally spreading tumor (LST) could be much harder to identify than a granular mixed LST. In this review, we present a summary of the evidence on the role of AI in the identification of colorectal flat neoplasia, with a focus on data regarding presence of LSTs in the training/validation sets of the AI systems currently available on the market.

S3119 Detection Rates of Adenoma, Clinically Significant Serrated Polyp, Proximal Serrated Polyp, and Laterally Spreading Tumors in Gastrointestinal Medicine (GI) Fellows

INTRODUCTION: Adenoma detection rate (ADR) is a widely accepted benchmark on quality for screening colonoscopy with studies suggesting 25% goal detection rates. Newer quality metrics like clinically significant serrated polyp detection rates (CSSDR) and proximal serrated polyp detection rates (PSDR) are being evaluated with suggested benchmarks of 7% and 11% respectively. CSSDR is defined as ≥1 sessile serrated adenoma or polyp, traditional serrated adenoma, hyperplastic polyp (HP) ≥ 1cm anywhere in the colon or any HP ≥ 5mm proximal to the sigmoid. PSDR is defined as a serrated polyp of any size proximal to the sigmoid colon. Another emerging milestone is the detection rate of laterally spreading tumors (LSTs). In this study, we evaluated the ADR, CSSDR, PSDR, and LSTs detection rates among GI fellows. METHODS: A retrospective analysis of 795 screening colonoscopy reports was performed at an urban academic hospital. The demographic data, GI fellow training years, and pathology results were collected by chart review. Statistical analysis using multiple linear regression models were used to evaluate effects of categorized covariates and logistic regression models to examine factors associated with ADR, CSSDR, PSDR, and LSTs. RESULTS: For our patient population, median age was 58, 49.8% were males, 46.3% Caucasians and 48.6% African Americans. 27.3% colonoscopies were done by first year fellows (F1s) and the rest by upper level fellows (ULs). Overall detection was 42.1% for ADR, 4.4% for CSSDR, 10.5% for PSDR, and 3.2% for LSTs. Between F1s and ULs, there was no statistical significance in ADR, CSSDR and PSDR. Detection of LSTs, however, showed trend toward significance with 0.9% detection rate in F1s and 4.0% in ULs (P = 0.05). The odds of detecting LSTs are expected to be 4 times higher for ULs compared to F1s (OR = 4.37, P = 0.048). CONCLUSION: In our study, GI fellows met the quality measure with an ADR of 42.1%. PSDR of 10.5% was comparable to the reported 11% in previous studies. CSSDR of 4.4% did not meet the 7% suggested by previous studies. The ability to detect ADR, CSSDR and PSDR did not significantly change between levels of training. The borderline significance of training level on LST detection rate could be attributed to more awareness of these lesions and higher volume of colonoscopies performed by upper levels. Similar studies in the future can help GI programs prioritize education in detecting these subtypes of polyps to improve screening.

S3373 Endoscopic Mucosal Resection of a Lateral Spreading Tumors Descending Colon

INTRODUCTION: Lateral spreading tumors (LST) are nonpolypoid lesions larger than 10 mm in width that extend laterally and circumferentially rather than vertically. These lesions have the potential for malignant transformation. Therefore, complete resection is recommended. However, given the fact that these lesions most of the time are flat in morphology and have large dimensions, complete resection using simple methods such as snare polypectomy is challenging. Endoscopic Mucosal Resection (EMR) and endoscopic mucosal dissection (ESD) are minimally invasive resection techniques that can be used to resect LST completely. Nonetheless, careful examination and evaluation of LST using high-quality images such as narrowband imaging (NBI) and Chromoendoscopy are important before performing EMR or ESD. Here, we present a case of large LST that was nicely demarcated using Chromoendoscopy. CASE DESCRIPTION/METHODS: A 71-year-old Caucasian male with multiple comorbidities who initially presented for colon cancer screening. LST greater than 2 cm in size and involving multiple folds was found. The lesion was encompassing >50% of mucosal surface of the descending colon. The polyp was carefully examined with narrowband imaging (NBI) and Chromoendoscopy (indigo carmine was sprayed on top of the lesion and subsequently crystal violet). The lesion met Paris classification 0–2A and Kudo pit pattern 3L. ORISE gel was injected to create a submucosal pillow at the base of this polyp and the polyp lifted well. The polyp was then completely resected via EMR. A small residual defect was seen but no closure was required. Histopathology report showed hyperplastic polyp. A follow-up colonoscopy was performed few months later. The resection site was notable for significant scarring and narrowing of the colonic lumen. The mucosa appeared pale with slightly larger pits, and irregular sparse vessels. However, there was no evidence of recurrent adenoma at the resection site upon evaluation by NBI and Chromoendoscpy. Biopsies were taken from the base of the resection site. Final histopathology report from the resection site showed tubular adenoma with low grade dysplasia. DISCUSSION: Careful examination and evaluation of LST by using chromoendoscopy and NBI are crucial before performing EMR or ESD safely and effectively.

Factors influencing interruption of colorectal endoscopic submucosal dissection.

Although colorectal endoscopic submucosal dissection (ESD) has become a standardized procedure worldwide, the difficulty of the procedure is well known. However, there have been no studies assessing the causes of treatment interruption. The present study aimed to evaluate the factors involved in the interruption of colorectal ESD. We retrospectively analyzed 1116 consecutive superficial colorectal neoplasms of 1012 patients who were treated with ESD between August 2008 and September 2018. The clinicopathological characteristics and treatment outcomes were analyzed. Interrupted ESD was reported in 14 lesions (1.3%) of the total study population. Univariate analysis of clinical characteristics indicated that age, 0-I macroscopic-type tumor, and tumor location on the left side colon were risk factors for interruption. Multivariate analysis revealed that 0-I macroscopic-type tumor was the sole preoperative independent risk factor for interruption. Univariate analysis revealed that the presence of muscle-retracting sign (MRS), deep submucosal tumor invasion, and intermediate invasive growth pattern represented the etiology of interruption. Multivariate analysis indicated that MRS can be a sole key sign for the interruption. Additionally, the resectability and curability of 0-I type tumors were significantly inferior to those of predominantly lateral spreading tumors. Observations of 0-I macroscopic-type tumors, MRS, and submucosal deep invasion were significantly more frequent in interrupted cases. Conventional endoscopic images without magnification endoscopy were more associated with interruption than irregular surfaces or Vi pit patterns in cases with 0-I type tumors. ESD of 0-I type tumors is highly disruptive, and undiagnosable submucosal infiltration can reduce the curability.

Efficacy and safety of endoscopic submucosal tunnel dissection for rectal laterally spreading tumors.

Evidence that comprehensively compares the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) with endoscopic submucosal dissection (ESD) for rectal laterally spreading tumors (LSTs) is limited. Between January 2009 and June 2018, 143 rectal LSTs in 143 patients who had undergone either ESD (n = 84) or ESTD (n = 59) were included in the study. One-to-one propensity score matching (PSM) was performed, and 50 pairs were selected. The data on patient demographics, treatment information, pathology reports, adverse events and follow-up were collected. Before PSM, the median specimen area was significantly larger in the ESTD group than in the ESD group (12.56 cm2 vs. 6.32 cm2, respectively; p < 0.001). The median dissection speed was significantly higher in the ESTD group than in the ESD group (24.53 mm2/min vs. 15.16 mm2/min, respectively; p < 0.001). After PSM, the median dissection speed was significantly higher in the ESTD group than in the ESD group (23.80 mm2/min vs. 17.12 mm2/min, respectively; p < 0.001). In multiple linear regression analysis, significant factors related to a higher dissection speed were the treatment method of ESTD (p < 0.001) and larger specimen area (p < 0.001). ESTD appears to be a safe and effective method to treat rectal LSTs. Compared with ESD, ESTD appears to achieve a higher dissection speed for rectal LSTs.

Blue laser imaging combined with JNET (Japan NBI Expert Team) classification for pathological prediction of colorectal laterally spreading tumors.

Blue laser imaging (BLI) can provide useful information on colorectal laterally spreading tumors (LSTs) by visualizing the surface and vessel patterns in detail. The present research aimed to evaluate the diagnostic performance of BLI-combined JNET (Japan NBI Expert Team) classification for identifying LSTs. This retrospective, multicenter study included 172 LSTs consisted of 6 hyperplastic polyps/sessile serrated polyps, 94 low-grade dysplasias (LGD), 60 high-grade dysplasias (HGD), 6 superficial submucosal invasive (m-SMs) carcinomas, and 4 deep submucosal invasive carcinomas. The relationship between the JNET classification and the histologic findings of these lesions were then analyzed. For all LSTs, non-experts and experts had a 79.7% and 90.7% accuracy for Type 2A (P = 0.004), a sensitivity of 94.7% and 96.8% (P = 0.718), and a specificity of 61.5% and 83.3% (P = 0.002) for prediction of LGD, respectively. The results also demonstrated 80.8% and 91.3% accuracy for Type 2B (P = 0.005), a sensitivity of 65.2% and 83.3% (P = 0.017), and a specificity of 90.6% and 96.2% (P = 0.097) for predicting HGD or m-SMs. For LST-granular (LST-G) lesions, Type 2A in experts had higher specificity (65.6% vs. 83.6%, P = 0.022) and accuracy (81.8% vs. 91.2%, P = 0.022). Type 2B in experts only had higher accuracy (82.5% vs. 92.0%, P = 0.019). However, no significant differences were noted for any comparisons between non-experts and experts for LST-non-granular (LST-NG) lesions. BLI combined with JNET classification was an effective method for the precise prediction of pathological diagnosis in patients with LSTs. Diagnostic performance of JNET classification by experts was better than that by non-experts for all examined LST or LST-G lesions when delineating between Type 2A and 2B, but there was no difference for the identification of LST-NG lesions by these two groups.