Nonpolypoid neoplastic lesions of the colorectal mucosa

Left-sided location is a risk factor for lymph node metastasis of T1 colorectal cancer: a single-center retrospective study

PURPOSE

Although some studies have reported differences in clinicopathological features between left- and right-sided advanced colorectal cancer (CRC), there are few reports regarding early-stage disease. In this study, we aimed to compare the clinicopathological features of left- and right-sided T1 CRC.

METHODS

Subjects were 1142 cases with T1 CRC undergoing surgical or endoscopic resection between 2001 and 2018 at Showa University Northern Yokohama Hospital. Of these, 776 cases were left-sided (descending colon to rectum) and 366 cases were right-sided (cecum to transverse colon). We compared clinical (patients age, sex, tumor size, morphology, initial treatment) and pathological features (invasion depth, histological grade, lymphatic invasion, vascular invasion, tumor budding) including lymph node metastasis (LNM).

RESULTS

Left-sided T1 CRC showed significantly higher rates of LNM (left-sided 12.0% vs. right-sided 5.4%, P < 0.05) and lymphatic invasion (left-sided 32.7% vs. right-sided 23.2%, P < 0.05). Especially, the sigmoid colon and rectum showed higher rates of LNM (12.4% and 12.1%, respectively) than other locations. Patients with left-sided T1 CRC were younger than those with right-sided T1 CRC (64.9 years ±11.5 years vs. 68.7 ± 11.6 years, P < 0.05), as well as significantly lower rates of poorly differentiated carcinoma/mucinous carcinoma than right-sided T1 CRC (11.6% vs. 16.1%, P < 0.05).

CONCLUSION

Left-sided T1 CRC, especially in the sigmoid colon and rectum, exhibited higher rates of LNM than right-sided T1 CRC, followed by higher rates of lymphatic invasion. These results suggest that tumor location should be considered in decisions regarding additional surgery after endoscopic resection.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Network Clinical Trials Registry ( UMIN 000032733 ).

Safety and efficacy of endoscopic submucosal dissection for rectal neoplasia: a multicenter North American experience

Background and aims  Rectal lesions traditionally represent the first lesions approached during endoscopic submucosal dissection (ESD) training in the West. We evaluated the safety and efficacy of rectal ESD in North America. Methods  This is a multicenter retrospective analysis of rectal ESD between January 2010 and September 2018 in 15 centers. End points included: rates of en bloc resection, R0 resection, adverse events, comparison of pre- and post-ESD histology, and factors associated with failed resection. Results  In total, 171 patients (median age 63 years; 56 % men) underwent rectal ESD (median size 43 mm). En bloc resection was achieved in 141 cases (82.5 %; 95 %CI 76.8-88.2), including 24 of 27 (88.9 %) with prior failed endoscopic mucosal resection (EMR). R0 resection rate was 74.9 % (95 %CI 68.4-81.4). Post-ESD bleeding and perforation occurred in 4 (2.3 %) and 7 (4.1 %), respectively. Covert submucosal invasive cancer (SMIC) was identified in 8.6 % of post-ESD specimens. There was one case (1/120; 0.8 %) of recurrence at a median follow-up of 31 weeks; IQR: 19-76 weeks). Older age and higher body mass index (BMI) were predictors of failed R0 resection, whereas submucosal fibrosis was associated with a higher likelihood of both failed en bloc and R0 resection. Conclusion  Rectal ESD in North America is safe and is associated with high en bloc and R0 resection rates. The presence of submucosal fibrosis was the main predictor of failed en bloc and R0 resection. ESD can be considered for select rectal lesions, and serves not only to establish a definitive tissue diagnosis but also to provide curative resection for lesions with covert advanced disease.

Impact of linked-color imaging on colorectal adenoma detection

BACKGROUND AND AIMS

Linked-color imaging (LCI) is a new technology that emphasizes changes in mucosal color by providing clearer and brighter images, thus allowing red and white areas to be visualized more clearly. We investigated whether LCI increases the detection of colorectal adenomas compared with white-light imaging (WLI) and blue-laser imaging (BLI)-bright.

METHODS

Consecutive patients undergoing colonoscopy were randomized (1:1:1) into examination by WLI, BLI-bright, or LCI during withdrawal of the colonoscope. The adenoma detection rate (ADR), mean number of adenomas per patient, and withdrawal time were evaluated. The lesions were evaluated according to size, morphology, location, and histology.

RESULTS

A total of 379 patients were randomized, and 412 adenomas were detected. The ADR was 43.2%, 54.0%, and 56.9% for WLI, BLI-bright, and LCI, respectively, and was significantly higher in the LCI group than in the WLI group (P = .03). No significant difference was observed between LCI and BLI-bright (P = .71) or BLI-bright and WLI (P = .09). The mean number of adenomas per patient was 0.82, 1.06, and 1.38 for WLI, BLI-bright, and LCI, respectively, with a significant difference between LCI and WLI (P = .03). Withdrawal time did not differ among the groups. A total of 102 adenomas were detected by WLI, 131 by BLI-bright, and 179 by LCI. LCI provided a higher rate of detection of adenomas ≤5 mm in size than WLI (P = .02), with a borderline significance for a higher detection of sessile serrated adenomas (P = .05). Nonpolypoid adenomas were more commonly located in the right colon segment and polypoid adenomas in the left colon segment, with a significant difference only between BLI-bright (P < .01) and LCI (P = .03).

CONCLUSIONS

Our findings show that LCI increases the detection of colorectal adenomas during colonoscopy. (Clinical trial registration number: RBR-9xg6dx.).

Prophylactic endoscopic coagulation to prevent delayed post-EMR bleeding in the colorectum: a prospective randomized controlled trial (with videos)

BACKGROUND AND AIMS

Post-EMR bleeding (PEB) is the most common adverse event after EMR. However, there are no established endoscopic methods for the prevention of PEB. This study aimed to investigate whether prophylactic endoscopic coagulation (PEC) using coagulation probes reduces the incidence of overall delayed PEB.

METHODS

We performed a randomized controlled study of patients undergoing EMR for large (≥10 mm) sessile lesions and laterally spreading tumors. Patients were randomized 1:1 to the EMR with coagulation group (n = 285) or EMR (control) group (n = 285). Immediate bleeding during colon EMR or clean-based ulcer after EMR was excluded. Clinically significant PEB was defined as bleeding requiring endoscopic hemostasis, hospitalization, or a decrease in the hemoglobin level >2 g/dL.

RESULTS

A total of 569 patients were analyzed. The incidence of overall PEB was significantly lower in the EMR with coagulation group than in the control group (12.6% [36/285] vs 18.7% [53/284], P = .048). However, this was largely because of a reduction in minor bleeding. There was no difference in clinically significant PEB (1.8% [5/285] vs 3.2% [9/284], P = .276). Rectal location was a risk factor associated with overall PEB (odds ratio, 1.256; 95% confidence interval, 1.12-1.41; P < .001).

CONCLUSIONS

Although this study found reduced PEB with prophylactic cautery of visible vessels, this was largely because of a reduction in minor bleeding with no benefit observed for clinically significant bleeding. Overall, PEB was more frequent with rectal lesions. (Clinical trial registration number: KCT0000779.).

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.

Switching from endoscopic submucosal dissection to salvage piecemeal knife-assisted snare resection to remove a lesion: A preoperative risk score from the beginning

BACKGROUND AND AIMS

endoscopic submucosal dissection (ESD) in the Western setting remains a challenge. Therefore, other simplified techniques such as knife-assisted snare resection (KAR) have been reported to overcome this issue.

METHODS

patients who underwent an ESD for the treatment of gastrointestinal neoplasms were included in a retrospective cross-sectional observational study. Factors associated with the end of ESD as a salvage p-KAR were identified and a logistic regression model was developed.

RESULTS

a total of 136 lesions in 133 patients were analyzed. Operator experience of under 50 cases and the combination of lesion size > 30 mm and colorectal location were independent predictive factors for switching to a salvage p-KAR according to the multivariate logistic regression analysis. We developed a risk scoring system based on these four variables (experience, size, location and the combination of size and location) with a receiver operating characteristic curve of 0.81 (95% CI: 0.74-0.89). The diagnostic accuracy of the score for a cut-off point ≥ 5 had a sensitivity of 0.79 (95% CI: 0.66-0.93) and a specificity of 0.71 (95% CI: 0.61-0.80).

CONCLUSION

a simple predictive score system that includes four preoperative factors accurately predicts ESD to finish as a p-KAR. A careful selection of cases considering these variables could be useful to achieve better outcomes in the Western setting.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Effect of Preceding Biopsy on the Results of Endoscopic Submucosal Dissection for Colorectal Laterally Spreading Tumor

BACKGROUND

Forceps biopsies are usually performed before endoscopic submucosal dissection (ESD) for colonic laterally spreading tumors (LSTs). However, preceding biopsy is commonly believed to possibly inhibit complete tumor resection by causing blurring of tumor borders and tissue fibrosis.

AIMS

The aims were to investigate whether the preceding biopsy of colorectal LST affects the complete endoscopic tumor resection and increases the risk of complications.

METHODS

We retrospectively reviewed the medical records of patients with colorectal LSTs who underwent ESD at our center during an 8-year period. Patients were divided into two groups according to whether they underwent biopsy of the tumor before ESD. In addition, the characteristics of patients and tumors, including the completeness of tumor resection, were investigated.

RESULTS

Of 288 patients (174 men) enrolled in this study, 194 (67.4%, preceding biopsy group) underwent biopsies before ESD, whereas 94 (32.6%, no biopsy group) did not. There were no significant differences in age, sex, comorbidity, medication history, tumor location, and final pathologic result between both groups. Tumor size was larger (p = 0.002) and LST-G tumor was more common (p = 0.003) in the preceding biopsy group than in the no biopsy group. No significant difference was seen in ESD outcomes, including procedure time, hospitalization period, incidence of complications, en bloc resection rate, resection margin status, and incidence of surgical operation, between both groups.

CONCLUSIONS

Biopsy of LST is commonly performed before endoscopic resection. Contrary to popular belief, it does not increase the incomplete tumor resection rate and incidence of complications.

TRIAL REGISTRATION

KCT0002321.

Effect of prophylactic endoscopic closure for an artificial ulceration after colorectal endoscopic submucosal dissection: a randomized controlled trial

Objective: Endoscopic submucosal dissection (ESD) is now commonly performed as a treatment for not only gastric tumor but also colorectal tumor. However, colorectal ESD has a substantial risk of complications, including post-ESD electrocoagulation syndrome, bowel perforation and bleeding. This study aimed to investigate whether prophylactic endoscopic closure can reduce the occurrence of complications after colorectal ESD.Materials and methods: Patients who underwent colorectal ESD in our unit were randomly assigned to either of two groups. Prophylactic endoscopic closure for an artificial ulceration after ESD was performed in group I but not in group II. After the procedure, the incidence of complications, visual analog scale (VAS) score for abdominal pain, and laboratory findings were investigated.Results: Of the 220 patients (110 per group) enrolled in this study, 137 were men. No significant differences were found in age, sex, comorbidity, medication history, tumor location, size of resected specimen, and pathologic result between the two groups. No significant difference was found in ESD outcomes, including hospitalization period, laboratory findings, VAS score for abdominal pain, incidence of surgical operation, and incidence of post-ESD complications, between the two groups.Conclusions: Contrary to popular belief, prophylactic endoscopic closure after colorectal ESD does not decrease the incidence of complications, and it does not ameliorate inflammatory response and abdominal pain.Clinical trial registration number: KCT0001666.

Endoscopic Assessment of the Malignant Potential of the Nonpolypoid (Flat and Depressed) Colorectal Neoplasms: Thinking Fast, and Slow

Current endoscopy training methodology does not meet the learning traits, skills, and needs of the newer generation of gastroenterologists. This article provides information on assessment of the malignant potential of colorectal neoplasms. It takes a modern approach on the topic and integrates relevant information that aligns with the thinking process. The theory of thinking fast (reflex) and slow (rational) is used. By doing so, it is hoped that the learning process can be expedited and practiced immediately. The focus is on preresection assessment of nonpolypoid colorectal neoplasms. Assessment of polypoid, sessile-serrated adenoma/polyp, or inflammatory bowel disease dysplasia is briefly discussed.

Comparison of Underwater vs Conventional Endoscopic Mucosal Resection of Intermediate-Size Colorectal Polyps

BACKGROUND & AIMS

Endoscopic mucosal resection (EMR) with submucosal injection is an established method for removing colorectal polyps, although the en bloc resection rate decreases when polyp size exceeds 10 mm. Piecemeal resection increases local recurrence. Underwater EMR (UEMR) is an effective technique for removal of sessile colorectal polyps and we investigated whether it is superior to conventional EMR (CEMR).

METHODS

We conducted a multicenter randomized controlled trial at 5 institutions in Japan. Patients with endoscopically diagnosed, intermediate-size (10-20 mm) sessile colorectal lesions were randomly assigned to undergo UEMR or CEMR. Only the most proximal lesion was registered. The UEMR procedure included immersion of the entire lumen in water and snare resection of the lesion without submucosal injection of normal saline. We analyzed outcomes of 108 colorectal lesions in the UEMR group and 102 lesions in the CEMR group. R0 resection was defined as en bloc resection with a histologically confirmed negative resection margin. The primary endpoint was the difference in the R0 resection rates between groups.

RESULTS

The proportions of R0 resections were 69% (95% confidence interval [CI] 59%-77%) in the UEMR group vs 50% (95% CI 40%-60%) in the CEMR group (P = .011). The proportions of en bloc resections were 89% (95% CI 81%-94%) in the UEMR group vs 75% (95% CI 65%-83%) in the CEMR group (P = .007). There was no significant difference in median procedure time (165 vs 175 seconds) or proportions of patients with adverse events (2.8% in the UEMR group vs 2.0% in the CEMR group).

CONCLUSIONS

In a multicenter randomized controlled trial, we found that UEMR significantly increased the proportions of R0 resections for 10- to 20-mm sessile colorectal lesions without increasing adverse events or procedure time. Use of this procedure should be encouraged. Trials registry number: UMIN000018989.

Saline-pocket endoscopic submucosal dissection for superficial colorectal neoplasms: a randomized controlled trial (with video)

BACKGROUND AND AIMS

Colorectal endoscopic submucosal dissection (ESD) is a time-consuming procedure because of the technical difficulty. The newly developed saline-pocket ESD (SP-ESD) provides a clearer view and better traction of the submucosal layer compared with the standard ESD with gas insufflation (S-ESD). This study aimed to prospectively compare the efficacy and safety between S-ESD and SP-ESD in patients with superficial colorectal neoplasms (SCNs).

METHODS

From April 2017 to November 2018, 95 patients with SCNs ≥20 mm in diameter were prospectively and randomly enrolled. Four patients were excluded because of an incomplete ESD procedure. Patients were finally allocated to 2 groups, S-ESD with 45 patients and SP-ESD with 46 patients. The primary outcome was dissection speed. Secondary outcomes were ESD procedure time, en bloc and complete resection rates, perforation rate, and adverse effects.

RESULTS

Median dissection speed was significantly faster in the SP-ESD than the S-ESD group (20.1 mm²/min [range, 17.3-28.1] vs 16.3 mm²/min [range, 11.4-19.8]; P < .001). Median procedure time was significantly shorter in the SP-ESD than the S-ESD group (29.5 minutes [range, 22.3-44] vs 41 minutes [range, 31-55]; P < .001). The en bloc and complete resection rates were 100% in both groups. No perforations occurred among patients. The volume of saline solution used in the SP-ESD group was significantly greater than that in the S-ESD group (200 mL [range, 120-250] vs 150 mL [range, 100-200]; P = .016).

CONCLUSIONS

SP-ESD improved dissection speed and procedure time compared with S-ESD. SP-ESD may be an alternative method for resection of SCNs. (Clinical trial registration number: UMIN 000026317.).

Predictors of invasive cancer of large laterally spreading colorectal tumors: A multicenter study in Japan

Background and Aim

Although colorectal laterally spreading tumors (LSTs) can be classified into four subtypes, the histopathological characteristics are known to differ among these subtypes. We therefore performed a logistic regression analysis to determine whether the risk of pathological T1 cancer of large colorectal LSTs can be predicted based on factors such as endoscopic findings in a large group of patients enrolled in a multicenter study in Japan.

Methods

In the main study, we assessed 1236 colorectal adenomas or early cancers that were classified as LSTs measuring 20 mm or more in diameter and treated endoscopically. Logistic regression analysis was performed to determine whether factors such as the subtype of LST could be used to predict the risk of pathological T1 cancer. A validation study of 356 large colorectal LSTs was conducted to confirm the validity of the results obtained in the main study.

Results

The locations and tumor diameter of the LSTs in the main study were found to differ significantly according to the LST subclassification (P < 0.001). The frequency of pathological T1 cancers was the highest at 36% of LST nongranular pseudodepressed type, followed by 14% of LST nongranular flat‐elevated type, 11% of LST granular nodular mixed type, and 3% of LST granular homogenous type lesions. The risk of pathological T1 cancer was significantly associated with LST subclassification and tumor diameter. The area under the curve (AUC) was high (0.743). In the validation study, the AUC was 0.573.

Conclusions

In patients with large colorectal LSTs resected endoscopically, the risk of pathological T1 cancer can be predicted on the basis of the LST subclassification and tumor diameter.

Endoscopic submucosal dissection with a grasping-type scissors for early colorectal epithelial neoplasms: a large single-center experience

Background and aims

The Clutch Cutter (CC) can grasp, pull, coagulate, and incise targeted tissue with the use of electrosurgical current. It was developed as a biopsy technique to reduce the technical difficulty of endoscopic submucosal dissection (ESD) with knives. The aim of this study was to evaluate the efficacy and safety of ESD using the CC (ESD-CC) for early colorectal epithelial neoplasms (ECENs).

Methods

In this prospective study, we enrolled 437 consecutive patients with a diagnosis of ECEN between January 2009 and January 2018. They all satisfied the Japanese colorectal cancer treatment guidelines for ESD; namely, confirmation by preliminary endoscopy, EUS, and endoscopic biopsy. The CC was used for all steps of ESD (mucosal incision, submucosal dissection, and hemostatic treatment); therapeutic efficacy and safety were assessed.

Results

The en bloc resection rate was 99.3% (434/437), and the R0 resection rate was 87.0% (380/437). The mean operating time was 88.3 minutes. Perforation occurred in 10 cases (2.3%) and was managed with conservative medical treatment. Post-ESD-CC bleeding occurred in 10 cases (2.3%) and was successfully treated by endoscopic hemostatic treatment.

Conclusions

ESD-CC is a technically efficient, safe, and easy method for resecting ECEN.

Multicentre randomised controlled trial comparing standard and high resolution optical technologies in colorectal cancer screening

BACKGROUND AND OBJECTIVES

The UK bowel cancer screening programme (BCSP) has been established for the early detection of colorectal cancer offering colonoscopy to patients screened positive by faecal occult blood tests. In this multisite, prospective, randomised controlled trial, we aimed to compare the performance of Standard Definition Olympus Lucera (SD-OL) with Scope Guide and the High Definition Pentax HiLine (HD-PHL).

PATIENTS AND METHODS

Subjects undergoing a colonoscopy as part of the UK National BCSP at four UK sites were randomised to an endoscopy list run using either SD-OL or HD-PHL. Primary endpoints were polyp and adenoma detection rate (PDR and ADR, respectively) as well as polyp size, morphology and histology characteristics.

RESULTS

262 subjects (168 males, mean age 66.3±4.3 years) were colonoscoped (133 patients with HD-PHL while 129 with SD-OL). PDR and ADR were comparable within the two optical systems. The HD-PHL group resulted in a PDR 55.6% and ADR 43.6%; the SD-OL group had PDR 56.6% and ADR 45.7%. HD-PHL was significantly superior to SD-OL in detection of flat adenomas (18.6% vs 5.2%, p<0.001), but not detection of pedunculated or sessile polyps. Patient comfort, use of sedation and endoscopist perception of procedural difficulty resulted similar despite the use of Scope Guide with SD-OL.

CONCLUSION

PDR and ADR were not significantly different between devices. The high-resolution colonoscopy system HD-PHL may improve polyp detection as compared with standard resolution technology in detecting flat adenomas. This advantage may have clinically significant implications for missed lesion rates and post-colonoscopy interval colorectal cancer rates.

Combined endoscopic submucosal dissection and transanal minimally invasive surgery for the management of lower rectal adenoma extending above the dentate line: A case report

RATIONALE

Minimally invasive surgery is used to treat early colorectal tumors. Endoscopic submucosal dissection (ESD) for resection of tumors extending above the dentate line (particularly those with concomitant hemorrhoids) is technically difficult. We present a case of a patient with a lower rectal adenoma extending above the dentate line, which underwent combined ESD and transanal minimally invasive surgery (TAMIS) to achieve accurate excision and prevent complications.

PATIENT CONCERNS

A 68-year-old man with a history of blood in stool over 2 to 3 years underwent colonoscopy, which revealed an adenoma measuring 3 cm in size in the lower rectum extending above the dentate line. The part extending above the dentate line was a type Is lesion and that of oral side was a type IIa lesion. Histopathologically, the lesion was diagnosed as a low-grade intramucosal tubulovillous adenoma.

DIAGNOSIS

Intramucosal low-grade adenoma with sessile polyp (type Is).

INTERVENTIONS

The cranial portion of the lesion was dissected via ESD and the anal portion via TAMIS with minimal bleeding. En bloc resection of the tumor was performed.

OUTCOMES

His postoperative period was uneventful, and he was discharged and regularly followed-up.

LESSONS

Combined ESD and TAMIS is effective in patients with benign and early neoplastic lesions of the anorectum extending above the dentate line with concomitant hemorrhoids and can prevent complications.

Endoscopic submucosal dissection for colorectal laterally spreading tumors with the Dual knife only

Introduction

The knives for endoscopic submucosal dissection (ESD) have their strengths as well as shortcomings. They need to be used in combination in most cases. The Dual knife is a relatively novel type of ESD knife produced in 2009, which can be used for completing the whole procedure of ESD.

Aim

Colorectal laterally spreading tumors (LSTs) are a special subtype of colorectal neoplasms. We aimed to evaluate the clinical features and outcomes of ESD for colorectal LSTs only using the Dual knife from our experience.

Material and methods

This retrospective study included 162 patients (each patient had 1 lesion) with colorectal LSTs treated by ESD with the Dual knife by a single endoscopist at our hospital between June 2015 and January 2018. We analyzed the clinical features and outcomes after resection.

Results

We obtained the en bloc ESD of the colorectal LSTs and the complete histological assessment in all patients. The mean age of the patients was 53.9 years. The mean diameter of lesions was 46 mm. The most common location of LSTs was the rectum. The most common histological type was tubular adenoma with 63 cases. The mean operating time was 56 min. Perforation and bleeding rates were 0.6% and 0.6%, respectively. No cases of local persistence or recurrence were observed at a follow-up endoscopy 6 to 31 months after the en bloc resection.

Conclusions

The ESD using the Dual knife only for colorectal LSTs has the advantages of safety, efficiency, and minimally invasiveness. It is worthy of widespread clinical application.

Role of Magnification Chromoendoscopy in the Management of Colorectal Neoplastic Lesions Suspicious for Submucosal Invasion

BACKGROUND

Correctly predicting the depth of tumor invasion in the colorectal wall is crucial for successful endoscopic resection of superficial colorectal neoplasms.

OBJECTIVE

The aim of this study was to assess the accuracy of magnifying chromoendoscopy in a Western medical center to predict the depth of invasion by the pit pattern classification in patients with colorectal neoplasms with a high risk of submucosal invasion.

DESIGN

This single-center retrospective study, from a prospectively collected database, was conducted between April 2009 and June 2015.

SETTINGS

The study was conducted at a single academic center.

PATIENTS

Consecutive patients with colorectal neoplasms with high risk of submucosal invasion were included. These tumors were defined by large (≥20 mm) sessile polyps (nonpedunculated), laterally spreading tumors, or depressed lesions of any size.

INTERVENTIONS

Patients underwent magnifying chromoendoscopy and were classified according to the Kudo pit pattern. The therapeutic decision, endoscopic or surgery, was defined by the magnification assessment.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive values of magnifying chromoendoscopy for assessment of these lesions were determined.

RESULTS

A total of 123 lesions were included, with a mean size of 54.0 ± 37.1 mm. Preoperative magnifying chromoendoscopy with pit pattern classification had 73.3% sensitivity, 100% specificity, 100% positive predictive value, 96.4% negative predictive value, and 96.7% accuracy to predict depth of invasion and consequently to guide the appropriate treatment. Thirty-three rectal lesions were also examined by MRI, and 31 were diagnosed as T2 lesions. Twenty two (70.1%) of these lesions were diagnosed as noninvasive by magnifying colonoscopy, were treated by endoscopic resection, and met the curative criteria.

LIMITATIONS

This was a single-center retrospective study with a single expert endoscopist experience.

CONCLUSIONS

Magnifying chromoendoscopy is highly accurate for assessing colorectal neoplasms suspicious for submucosal invasion and can help to select the most appropriate treatment. See Video Abstract at http://links.lww.com/DCR/A920.

Combination of endoscopic submucosal dissection and transanal minimally invasive surgery for the resection of early rectal cancer with fibrosis after prior partial excision

Endoscopic submucosal dissection is an effective procedure for treating non-invasive colorectal tumors. However, in cases of severe fibrosis, endoscopic submucosal dissection may be technically difficult, leading to incomplete resection. Here, we describe the case of a 74-year-old man who had early rectal cancer along with severe submucosal fibrosis caused by prior local excision. Combination treatment with endoscopic submucosal dissection and transanal minimally invasive surgery successfully enabled complete resection.

Preoperative endoscopic predictors of severe submucosal fibrosis in colorectal tumors undergoing endoscopic submucosal dissection

Background and study aims  Endoscopic submucosal dissection (ESD) enables en bloc removal of colorectal neoplasms regardless of size. Submucosal fibrosis is a significant factor for technical difficulty and poor outcomes. We assessed the predictive factors for severe submucosal fibrosis and the ESD outcomes. Patients and methods  Patients undergoing ESD from January 2006 to September 2017 were retrospectively reviewed. The degree of submucosal fibrosis was classified into three types: no fibrosis (F0), mild fibrosis (F1), and severe fibrosis (F2). F0 and F1 cases were grouped as non-severe fibrosis for comparison with the severe fibrosis group. Predictors of severe submucosal fibrosis and ESD outcomes were evaluated. Results  ESD was performed in 524 lesions (60 % male; mean age, 67.8 years). Eighty lesions with severe fibrosis (15.3 %) were observed. The overall en bloc resection rate and curative resection rate were 94.3 % and 77.7 %, respectively. Rates of en bloc resection (91.2 % vs. 94.8 %, P  = 0.2) and perforation (7.5 % vs. 5.6 %, P  = 0.45) were no different between severe fibrosis and non-severe fibrosis groups. However, incidences of non-curative resection and low resection speed were significantly higher in the severe fibrosis group. Among protruding lesions, tumor height and volume were significantly greater in the severe counterparts. A diameter ≥ 40 mm, endoscopic finding of the tumor beyond fold, and fold convergence were independent risk factors for severe fibrosis. Conclusions  Severe submucosal fibrosis is a significant risk factor for non-curative resection and a long procedural time. Tumor size and morphology might help to predict the severity of fibrosis.

Endoscopic Submucosal Dissection for Colitis-Associated Dysplasia

Dysplasia is a precancerous lesion of colorectal cancer in patients with long-standing inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn’s disease. Recent guidelines suggest endoscopic resection as a key modality for the treatment of endoscopically resectable dysplasia in patients with colitis. Endoscopic submucosal dissection (ESD) has been suggested as one of the therapeutic options for dysplasia that is potentially resectable but not suitable for the conventional endoscopic mucosal resection technique. Several recent studies supported the feasibility of ESD for the treatment of colitis-associated dysplasia in terms of the en bloc and complete resection rates and the risk of procedure-related complications. However, these studies were performed exclusively in expert centers. Moreover, the local and metachronous recurrence rates were relatively high, and long-term outcome data are still lacking. Endoscopists should be highly skilled in colorectal ESD and have an intensive understanding of not only the lesions but also the conditions of patients with IBDs. Therefore, the decision to perform ESD for colitis-associated dysplasia should be made scrupulously after careful discussion with patients, in collaboration with a multidisciplinary IBD team including physicians, surgeons, and pathologists specialized in IBDs.

Estimation of Invasion Depth: The First Key to Successful Colorectal ESD

Colorectal tumors with superficial submucosal invasion, which cannot be removed by snaring, are one of the most optimal indications for colorectal endoscopic submucosal dissection (ESD). Therefore, estimation of the invasion depth is the first key to successful colorectal ESD. Although estimation of the invasion depth based on the gross morphology may be useful in selected cases, its diagnostic accuracy could not reach the clinical requirement. The Japan Narrow-band Imaging (NBI) Expert Team (JNET) classification of NBI magnifying endoscopy findings is a useful method for histologic prediction and invasion depth estimation. However, magnifying chromoendoscopy is still necessary for JNET type 2B lesions to reach a satisfactory diagnostic accuracy. Endocytoscopy with artificial intelligence is a promising technology in invasion depth estimation; however, more data are needed for its clinical application.

Long-term prognosis after treatment for T1 carcinoma of laterally spreading tumors: a multicenter retrospective study

PURPOSE

Long-term prognosis of T1 laterally spreading tumors (LSTs) after treatment have not been clarified. This study compared clinicopathological characteristics and long-term prognosis of T1 LSTs.

METHODS

We retrospectively assessed 169 patients with 169 T1 LSTs between January 1992 and December 2008 by ten hospitals. Patients who did not meet the Japanese Society for Cancer of the Colon and Rectum (JSCCR) 2016 guidelines for the treatment of colorectal carcinoma (CRC) criteria were defined as non-endoscopically curable. The number of non-endoscopically curable patients with LST-granular/ nodular mixed (LST-G-M) was 61, that with LST-non-granular/ flat elevated (LST-NG-FE) was 23, and that with LST-non-granular/ pseudo depressed (LST-NG-PD) was 23. Clinicopathological variables and long-term prognosis were analyzed.

RESULTS

For overall patients, tumor size, number of non-endoscopically curable cases, and rate of submucosal invasion depth ≥ 1000 μm for the LST-G-M group were significantly higher than those in the other groups. For non-endoscopically curable patients, the tumor size for those with LST-G-M was significantly larger than those in the other groups. The rate of submucosal invasion width ≥ 4000 μm and type B/C muscularis mucosae with LST-G-M was higher than that with LST-NG-FE. All recurrences occurred in non-endoscopically curable patients with LST-G-M. Five-year overall and disease-free survivals for non-endoscopically curable patients with LST-G-M were significantly shorter than those for patients with non-endoscopically curable LST-NG-FE and PD.

CONCLUSIONS

Our data supported adequacy of the JSCCR guidelines for the treatment of CRC criteria for endoscopically curable patients after T1 LSTs treatment. Patients with T1 LST-G-M should be followed up more carefully.

Efficacy of autofluorescence imaging for flat neoplasm detection: a multicenter randomized controlled trial (A-FLAT trial)

BACKGROUND AND AIMS

Colorectal flat (nonpolypoid) lesions can be overlooked during colonoscopy. This study evaluated the efficacy of updated autofluorescence imaging (AFI) for detecting colorectal flat neoplasms.

METHODS

This was a prospective, multicenter, randomized controlled trial in 9 Japanese tertiary institutions. Patients undergoing colonoscopy because of positive fecal immunochemical tests, surveillance after polypectomy, or investigation of minor symptoms were enrolled and randomly assigned to either the white-light imaging (WLI) or the AFI group. Primary outcome measurement was number of flat neoplasms per patient.

RESULTS

From November 2015 to June 2017, 817 patients were enrolled. After excluding 15 patients, 802 were finally analyzed (404, WLI; 398, AFI). Patients' backgrounds (sex, age, indication of colonoscopy, experience of endoscopists) and quality of colonoscopy (bowel preparation, sedative use, cecal insertion rate, insertion and withdrawal time) were not different between groups. Number of flat neoplasms in each patient was significantly higher in the AFI than in the WLI group (.87 [95% confidence interval [CI], .78-.97] vs .53 [95% CI, .46-.61]), whereas overall and polypoid neoplasm detection was not significantly different between the groups (1.33 [95% CI, 1.22-1.45] vs 1.14 [95% CI, 1.03-1.24], .46 [95% CI, .40-.53] vs .60 [95% CI, .53-.68]). Flat neoplasms were more frequently detected in the right-sided colon with AFI (.61 [95% CI, .54-.70] vs .30 [95% CI, .25-.36]) but not in the left-sided colon and rectum (.26 [95% CI, .21-.32] vs .23 [95% CI, .19-.28]).

CONCLUSIONS

Updated AFI improves the detection of flat colorectal neoplasms in the right-sided colon compared with WLI. (Clinical trial registration number: UMIN000019355.).

A retrospective comparative study of argon plasma versus polypectome snare tip coagulation: effect on recurrence rate after resection of large laterally spreading type lesions

Background

Endoscopic mucosal resection (EMR) is an established technique for treating large laterally spreading type (LST) lesions ≥20 mm. The aim of our study was to compare the use of argon plasma (APC) versus snare-tip coagulation on the recurrence rate of large LST lesions.

Methods

All patients with large LST lesions resected by EMR between January 2006 and December 2014 were enrolled. After piecemeal resection, patients underwent either APC or snare-tip coagulation of the rim of the resection area and any residual adenomatous tissue. Follow up included colonoscopy and biopsies. Medical records, including characteristics of patients and polyps, complications and recurrence were retrieved and collected.

Results

One hundred one patients were included in the final analysis. They were divided into the APC group (n=50) and the snare-tip coagulation group (n=51). The 2 groups were similar concerning patients’ characteristics, size of polyps and histology. Post-polypectomy coagulation syndrome was observed in 8 patients (7.9%) (APC group: n=5 and snare tip group: n=3). EMR-related bleeding occurred in 9 patients (8.9%) (APC group: n=4 and snare tip group: n=5). Total recurrence rate was 14.85% (16% and 13.7% in APC and snare-tip groups, respectively, P=0.34).

Conclusion

The effectiveness of snare-tip coagulation is comparable with that of APC with respect to recurrence rate after resection of large LST lesions. It thus represents a cost-effective alternative to APC.

Clinical outcomes of endoscopic submucosal dissection for laterally spreading tumors involving the dentate line

OBJECTIVE

Endoscopic submucosal dissection (ESD) for laterally spreading tumors (LST) involving the dentate line (LST-DL) is challenging because of the specific anatomical features of the anorectum. This study aimed to evaluate the efficacy and safety of ESD for LST-DL.

METHODS

Consecutive patients with LST-DL who had undergone ESD at our hospital between January 2010 and December 2015 were retrospectively enrolled in this study. Rates of en bloc resection, R0 resection, and complications, pathological characteristics, and tumor recurrence were analyzed and compared with those of LST in the rectum not involving the dentate line (LST-NDL).

RESULTS

Altogether 49 patients with LST-DL (median age 63 years; 39 women; median lesion size 57 mm; median follow-up period of 24 months) and 96 patients with LST-NDL (median age 67 years; 31 women; median lesion size 47 mm; median follow-up period of 31 months) were enrolled. En bloc resection (93.9% [46/49] vs 94.8% [91/96]) and en bloc R0 resection rates (83.7% [41/49] vs 88.5% [85/96]), respectively, for LST-DL and LST-NDL, with no significant differences. However, ESD for LST-DL had a longer procedure time (77 min vs 54 min, P = 0.02), a greater postprocedural perianal pain rate (28.6% vs 0%, P < 0.001), and more anal strictures (4.1% vs 0%, P = 0.04). The complication rates of perforation, bleeding and fever, recurrence rate, and pathological characteristics did not differ between the two groups.

CONCLUSIONS

ESD is a safe and effective therapeutic modality for LST-DL. However, this procedure should be performed by experienced endoscopists and the difficulty needs to be fully considered.

Management of colorectal laterally spreading tumors: a systematic review and meta-analysis

Objective and study aims  To evaluate the efficacy and safety of different endoscopic resection techniques for laterally spreading colorectal tumors (LST). Methods  Relevant studies were identified in three electronic databases (PubMed, ISI and Cochrane Central Register). We considered all clinical studies in which colorectal LST were treated with endoscopic resection (endoscopic mucosal resection [EMR] and/or endoscopic submucosal dissection [ESD]) and/or transanal minimally invasive surgery (TEMS). Rates of en-bloc/piecemeal resection, complete endoscopic resection, R0 resection, curative resection, adverse events (AEs) or recurrence, were extracted. Study quality was assessed with the Newcastle-Ottawa Scale and a meta-analysis was performed using a random-effects model. Results  Forty-nine studies were included. Complete resection was similar between techniques (EMR 99.5 % [95 % CI 98.6 %-100 %] vs. ESD 97.9 % [95 % CI 96.1 - 99.2 %]), being curative in 1685/1895 (13 studies, pooled curative resection 90 %, 95 % CI 86.6 - 92.9 %, I ²  = 79 %) with non-significantly higher curative resection rates with ESD (93.6 %, 95 % CI 91.3 - 95.5 %, vs. 84 % 95 % CI 78.1 - 89.3 % with EMR). ESD was also associated with a significantly higher perforation risk (pooled incidence 5.9 %, 95 % CI 4.3 - 7.9 %, vs. EMR 1.2 %, 95 % CI 0.5 - 2.3 %) while bleeding was significantly more frequent with EMR (9.6 %, 95 % CI 6.5 - 13.2 %; vs. ESD 2.8 %, 95 % CI 1.9 - 4.0 %). Procedure-related mortality was 0.1 %. Recurrence occurred in 5.5 %, more often with EMR (12.6 %, 95 % CI 9.1 - 16.6 % vs. ESD 1.1 %, 95 % CI 0.3 - 2.5 %), with most amenable to successful endoscopic treatment (87.7 %, 95 % CI 81.1 - 93.1 %). Surgery was limited to 2.7 % of the lesions, 0.5 % due to AEs. No data of TEMS were available for LST. Conclusions  EMR and ESD are both effective and safe and are associated with a very low risk of procedure related mortality.

Multicentre prospective evaluation of real-time optical diagnosis of T1 colorectal cancer in large non-pedunculated colorectal polyps using narrow band imaging (the OPTICAL study)

OBJECTIVE

This study evaluated the preresection accuracy of optical diagnosis of T1 colorectal cancer (CRC) in large non-pedunculated colorectal polyps (LNPCPs).

DESIGN

In this multicentre prospective study, endoscopists predicted the histology during colonoscopy in consecutive patients with LNPCPs using a standardised procedure for optical assessment. The presence of morphological features assessed with white light, and vascular and surface pattern with narrow-band imaging (NBI) were recorded, together with the optical diagnosis, the confidence level of prediction and the recommended treatment. A risk score chart was developed and validated using a multivariable mixed effects binary logistic least absolute shrinkage and selection (LASSO) model.

RESULTS

Among 343 LNPCPs, 47 cancers were found (36 T1 CRCs and 11 ≥T2 CRCs), of which 11 T1 CRCs were superficial invasive T1 CRCs (23.4% of all malignant polyps). Sensitivity and specificity for optical diagnosis of T1 CRC were 78.7% (95% CI 64.3 to 89.3) and 94.2% (95% CI 90.9 to 96.6), and 63.3% (95% CI 43.9 to 80.1) and 99.0% (95% CI 97.1 to 100.0) for optical diagnosis of endoscopically unresectable lesions (ie, ≥T1 CRC with deep invasion), respectively. A LASSO-derived model using white light and NBI features discriminated T1 CRCs from non-invasive polyps with a cross-validation area under the curve (AUC) of 0.85 (95% CI 0.80 to 0.90). This model was validated in a temporal validation set of 100 LNPCPs (AUC of 0.81; 95% CI 0.66 to 0.96).

CONCLUSION

Our study provides insights in the preresection accuracy of optical diagnosis of T1 CRC. Sensitivity is still limited, so further studies will show how the risk score chart could be improved and finally used for clinical decision making with regard to the type of endoresection to be used and whether to proceed to surgery instead of endoscopy.

TRIAL REGISTRATION NUMBER

NTR5561.

Quality measures improving endoscopic screening of colorectal cancer: a review of the literature

INTRODUCTION

Colorectal cancer (CRC) is a major health-care problem all over the world and CRC screening is effective in reducing mortality and increasing the 5-year survival. Colonoscopy has a central role in CRC screening. It can be performed as a primary test, as a recall policy after a positive result of another screening test, and for surveillance. Since effectiveness of endoscopic screening depends on adequate detection and removal of colonic polyps, consistent quality measures, which are useful in enhancing the diagnostic yield of examination, are essential. Areas covered: The aim of this review is to analyze current evidence from literature supporting quality measures able to refine endoscopic screening of colorectal cancer. Expert commentary: Quality measures namely a) time slot allotted to colonoscopy, b) assessment of indication, c) bowel preparation, d) Cecal intubation, e) withdrawal time, f) adenoma detection rate, g) proper management of lesions (polypectomy technique, polyps retrieval rate and tattooing of resection sites), and h) adequate follow-up intervals play a key role in identifying malignant and at-risk lesions and improving the outcome of screening. Adherence to these quality measures is critical to maximize the effectiveness of CRC screening, as well as, a proper technique of colonoscopy and a quality report of the procedure. Among all recommended measures, adenoma detection rate is the most important and must be kept above the recommended quality threshold by all physicians practicing in the setting of screening.

Clinicopathological features of T1 colorectal carcinomas with skip lymphovascular invasion

With recent advances in endoscopic treatment, many T1 colorectal carcinomas (CRCs) are resected endoscopically with a negative margin. However, some lesions exhibit skip lymphovascular invasion (SLVI), which is defined as the discontinuous foci of the tumor cells within the colon wall. The aim of the present study was to reveal the clinicopathological features of T1 CRCs with SLVI and validate the Japanese guidelines regarding SLVI. A total of 741 patients with T1 CRCs that were resected surgically between April 2001 and October 2016 in our hospital were divided into two groups: With SLVI and without SLVI. Clinicopathological features compared between the two groups were patient's gender, age, tumor size, location, morphology, lymphovascular invasion, tumor differentiation, tumor budding and lymph node metastasis. The incidence of T1 CRCs with SLVI was 0.9% (7/741). All cases with SLVI were found in the sigmoid colon or rectum. T1 CRCs with SLVI showed significantly higher rates of lymphovascular invasion than those without SLVI (P<0.01). In conclusion, lymphovascular invasion was a significant risk factor for SLVI in T1 CRCs, and for which surgical colectomy was necessary. The Japanese guidelines are appropriate regarding SLVI. Registered in the University Hospital Medical Network Clinical Trials Registry (UMIN000027097).

Clinical management of endoscopically resected pT1 colorectal cancer

Background  Implementation of colorectal cancer (CRC) screening programs increases endoscopic resection of polyps with early invasive CRC (pT1). Risk of lymph node metastasis often leads to additional surgery, but despite guidelines, correct management remains unclear. Our aim was to assess the factors affecting the decision-making process in endoscopically resected pT1-CRCs in an academic center. Methods  We retrospectively reviewed patients undergoing endoscopic resection of pT1 CRC from 2006 to 2016. Clinical, endoscopic, surgical treatment, and follow-up data were collected and analyzed. Lesions were categorized according to endoscopic/histological risk-factors into low and high risk groups. Comorbidities were classified according to the Charlson comorbidity index (CCI). Surgical referral for each group was computed, and dissociation from current European CRC screening guidelines recorded. Multivariate analysis for factors affecting the post-endoscopic surgery referral was performed. Results  Seventy-two patients with endoscopically resected pT1-CRC were included. Overall, 20 (27.7 %) and 52 (72.3 %) were classified as low and high risk, respectively. In the low risk group, 11 (55 %) were referred to surgery, representing over-treatment compared with current guidelines. In the high risk group, nonsurgical endoscopic surveillance was performed in 20 (38.5 %) cases, representing potential under-treatment. After a median follow-up of 30 (6 - 130) months, no patients developed tumor recurrence. At multivariate analysis, age (OR 1.21, 95 %CI 1.02 - 1.42; P  = 0.02) and CCI (OR 1.67, 95 %CI 1.12 - 3.14; P  = 0.04) were independent predictors for subsequent surgery. Conclusions  A substantial rate of inappropriate post-endoscopic treatment of pT1-CRC was observed when compared with current guidelines. This was apparently related to an overestimation of patient-related factors rather than endoscopically or histologically related factors.

Surface microstructures are associated with mutational intratumoral heterogeneity in colorectal tumors

BACKGROUND

Recent studies revealed that colorectal tumors are composed of genetically diverse subclones. We aimed to clarify whether the surface microstructures of colorectal tumors are associated with genetic intratumoral heterogeneity (ITH).

METHODS

The surface microstructures (pit patterns) of colorectal tumors were observed using magnifying endoscopy, and biopsy specimens were obtained from respective areas when tumors exhibited multiple pit patterns. A total of 711 specimens from 477 colorectal tumors were analyzed for BRAF, KRAS and TP53 mutations using pyrosequencing and direct sequencing. A panel of cancer-related genes was analyzed through targeted sequencing in 7 tumors.

RESULTS

Colorectal tumors with multiple pit patterns exhibited more advanced pit patterns and higher frequencies of KRAS and/or TP53 mutations than tumors with a single pit pattern. In tumors with multiple pit patterns, mutations were observed as public (common to all areas) or private (specific to certain areas), and private KRAS and/or TP53 mutations were often variable and unrelated to the pit pattern grade. Notably, invasive CRCs frequently exhibited public TP53 mutations, even in adenomatous areas, which is indicative of their early malignant potential. Targeted sequencing revealed additional public and private mutations in tumors with multiple pit patterns, indicating their single clonal origin.

CONCLUSIONS

Our results suggest intratumoral pit pattern variation does not simply reflect the process of colorectal tumor evolution, but instead represents genetically diverse subclones, and this diversity may be associated with malignant potential.

Blue laser imaging: a new image-enhanced endoscopy for the diagnosis of colorectal lesions

BACKGROUND

Image-enhanced endoscopy enables real-time differential diagnosis of colorectal lesions through the observation of microvascular architecture.

PURPOSE

To evaluate the efficacy of using blue laser imaging (BLI) for capillary pattern analysis in the differential diagnosis of neoplastic and non-neoplastic lesions.

PATIENTS AND METHODS

This prospective study included 920 consecutive superficial lesions diagnosed in 457 patients. The capillary pattern was analysed using BLI-bright magnification on the basis of the Teixeira classification. Histopathology was used as the reference standard.

RESULTS

The adenoma detection rate was 42.3%, with a mean of 0.95 adenomas per patient. Neoplastic lesions were predominant (70.3%), of which 33 (5.1%) had advanced histology. Neoplastic progression was significantly increased in patients aged at least 50 years, in lesions at least 10 mm and in lesions located in the right colon (P<0.01). BLI-based capillary pattern analysis showed 95.5% accuracy, 95.7% sensitivity, 95.2% specificity, 97.9% positive predictive value and 90.3% negative predictive value in the diagnosis of neoplastic lesions. For 672 diminutive lesions (≤5 mm), BLI-based capillary pattern analysis showed 95.7% accuracy, 96.6% sensitivity, 93.6% specificity, 97.2% positive predictive value and 92.2% negative predictive value. Analysing only lesions up to 5 mm in the rectum and sigmoid colon, the values were 95.2, 93.9, 96.5, 95.8 and 94.8%, respectively.

CONCLUSION

BLI associated with magnification yielded excellent results for the real-time predictive histological diagnosis of colorectal lesions.

Safety of simultaneous endoscopic submucosal dissection for two large colorectal neoplasias in the same patient

BACKGROUND/AIMS

Multiple large colorectal lesions requiring endoscopic submucosal dissection (ESD) are sometimes diagnosed during colonoscopy. We evaluated the feasibility and safety of ESD of two colorectal lesions in one session.

MATERIALS AND METHODS

The lesions of 16 patients who underwent two ESD procedures in a single session (double ESD group) from November 2009 to July 2014 were matched with those of 64 patients who underwent a single ESD procedure (single ESD group) based on the size and location of the lesion and presence of submucosal fibrosis.

RESULTS

The net ESD time per patient was longer in double ESD group than in single ESD group (104.0±36.2 vs. 59.1±39.2 min, p<0.001). The net ESD time per lesion tended to be shorter in double ESD group than in single ESD group (49.6±30.0 vs. 59.1±39.2 min, p=0.077). The en bloc resection and curative resection rates did not differ between double ESD and single ESD groups (93.8 % vs. 98.4%, p=0.262; 90.6 % vs. 84.4 %, p=0.534, respectively). The intra- and postprocedural bleeding rates were 12.5% and 0% in double ESD group and 15.6% and 3.1% in single ESD group, respectively. Perforation occurred in two (6.3%) in double ESD group and in six (9.4%) in single ESD group (p=0.715).

CONCLUSION

Compared with the single ESD, two simultaneous colorectal ESD procedures in a patient did not increase complications; the en bloc and curative resection rates were similar when performed a single ESD procedure and two simultaneous ESD procedures.

A comparison of the resection rate for cold and hot snare polypectomy for 4-9 mm colorectal polyps: a multicentre randomised controlled trial (CRESCENT study)

OBJECTIVE

To investigate the success rate of cold snare polypectomy (CSP) for complete resection of 4-9 mm colorectal adenomatous polyps compared with that of hot snare polypectomy (HSP).

DESIGN

A prospective, multicentre, randomised controlled, parallel, non-inferiority trial conducted in 12 Japanese endoscopy units. Endoscopically diagnosed sessile adenomatous polyps, 4-9 mm in size, were randomly assigned to the CSP or HSP group. After complete removal of the polyp using the allocated technique, biopsy specimens from the resection margin after polypectomy were obtained. The primary endpoint was the complete resection rate, defined as no evidence of adenomatous tissue in the biopsied specimens, among all pathologically confirmed adenomatous polyps.

RESULTS

A total of 796 eligible polyps were detected in 538 of 912 patients screened for eligibility between September 2015 and August 2016. The complete resection rate for CSP was 98.2% compared with 97.4% for HSP. The non-inferiority of CSP for complete resection compared with HSP was confirmed by the +0.8% (90% CI -1.0 to 2.7) complete resection rate (non-inferiority p<0.0001). Postoperative bleeding requiring endoscopic haemostasis occurred only in the HSP group (0.5%, 2 of 402 polyps).

CONCLUSIONS

The complete resection rate for CSP is not inferior to that for HSP. CSP can be one of the standard techniques for 4-9 mm colorectal polyps. (Study registration: UMIN000018328).

Endoscopic submucosal dissection for rectal neoplasia extending to the dentate line: European experience

Background and study aims  The ideal treatment strategy for rectal neoplasia extending to the dentate line (RNDL) is not well defined. Endoscopic mucosal resection (EMR) and submucosal dissection (ESD) compete with surgical techniques such as transanal endoscopic microsurgery (TEM). Non-Asian data and prospective data on ESD are lacking. The study aim was to evaluate the role of ESD in treatment of RNDL in a Western center. Patients and methods  Eighty-six patients with rectal adenomas were included. ESD was performed in 86 rectal adenomas including 24 RNDLs (27.9 %) and 62 lesions distant from the dentate line (72.1 %). Results  En bloc resection rate was comparable (91.7 % vs. 93.5 %, P  = 0.670) between ESD for RNDL and non-RNDL. R0 resection rate was significantly lower in ESD for RNDL compared to that for non-RNDL (70.8 % vs 88.7 %; P  = 0.039), but most non-R0 resection was unclear margin (Rx) and was not obvious positive margin (R1). Accordingly, the recurrence rate after ESD for RNDL (4.5 %) was not statistically different from that for non-RNDL (0 %, P  = 0.275) and was lower than that previously reported for EMR. Median procedure time was 127 vs. 110 minutes ( P  = 0.182). Risk of delayed bleeding (20.8 % vs. 0 %, P  = 0.001) and postinterventional pain (33.3 % vs. 14.5 %, P  = 0.07) increased in RNDL cases, but they were managed conservatively. Incidence of stricture (4.2 % vs. 1.6 %, P  = 0.483) and perforation (0 % vs. 1.6 %, P  = 1.000) were similar. Conclusions  ESD is a feasible and safe resection technique for RNDLs. A randomized controlled trial comparing ESD to other methods (EMR or transanal surgery) is warranted.

Invasive pit pattern, macronodule and depression are predictive factors of submucosal invasion in colorectal laterally spreading tumours from a Western population

Background

Laterally spreading tumours are separated in subclasses: granular, homogenous or nodular mixed; and non-granular, flat or pseudodepressed. For every subtype, a proper risk of submucosal invasive cancer has been described in Asian series.

Objective

The aim of the study was to determine the rate of cancer and submucosal invasive cancer in a Western series of endoscopic-resected laterally spreading tumours and their endoscopic predictive factors.

Methods

A total of 374 laterally spreading tumours ≥20 mm were resected by endoscopy in our single centre between 2012-2016. We analysed endoscopic and pathological data from our prospective database, determining the rates of cancer and submucosal invasive cancer according to the subtype of laterally spreading tumour.

Results

The rates of submucosal invasive cancer for granular homogenous, granular nodular mixed, non-granular flat, non-granular pseudodepressed laterally spreading tumours were 4.9%, 15.9%, 3.0% and 19.4%, respectively. Endoscopic mucosal resection was used in 58.0% and endoscopic submucosal dissection in 42.0%. Endoscopic submucosal dissection was associated with a higher rate of en-bloc resection (87.3% vs 26.3%; p < 0.0001), and a lower risk of recurrence (7.6% vs 15.2%; p = 0.026). Adverse event rates were not statistically different (9.5% vs 6.4%, p = 0.26). Predictive endoscopic factors of submucosal invasive cancer were: invasive pit pattern (hazard ratio = 33 (8.81-143.3)), non-granular pseudodepressed laterally spreading tumours (hazard ratio = 11.9 (0.89-146.2)), and granular nodular mixed laterally spreading tumours (hazard ratio = 3.42 (0.99-13.0)).

Conclusions

The risk of submucosal invasive cancer varies according to the laterally spreading tumour subtype. Three factors were associated with submucosal invasion and should justify an endoscopic submucosal dissection: non-granular pseudodepressed laterally spreading tumours, granular nodular mixed laterally spreading tumours subtypes and invasive pit pattern.

Clinical and endoscopic evaluations of sessile serrated adenoma/polyps with cytological dysplasia

BACKGROUND AND AIM

Although sessile serrated adenoma/polyps (SSA/Ps) are considered to be premalignant lesions and rapidly progress to carcinomas after they develop cytological dysplasia (CD), a treatment strategy for SSA/Ps in Asian countries is still being debated and has not yet been established. The present study aimed to propose a treatment strategy for SSA/Ps.

METHODS

Histopathological data of patients, who underwent colonoscopy at our center between January 2011 and December 2016, were reviewed. Data of patients with ≥ 1 SSA/P were retrieved, and clinicopathological characteristics were retrospectively analyzed.

RESULTS

A total of 281 patients with 326 SSA/Ps, including 258 patients who had 300 SSA/Ps without CD (SSA/Ps-CD[-]) and 23 patients who had 26 SSA/Ps with CD (SSA/Ps-CD[+]), were evaluated in this study. Although SSA/Ps-CD(+) were often found in older female patients and in the proximal colon, there were no significant differences between SSA/Ps-CD(-) and SSA/Ps-CD(+). Endoscopic morphological findings, such as large or small nodules on the surface and partial protrusion of the lesions, were significantly more common in SSA/Ps-CD(+) than in SSA/Ps-CD(-). Although the diagnostic ability of nodule/protrusion in lesions to predict CD within SSA/Ps was very high with an accuracy of 93.9% and a negative predictive value of 95.4%, sensitivity was low at 46.2%. SSA/Ps-CD(+) were significantly larger than SSA/Ps-CD(-), and the rate of CD within SSA/Ps significantly increased with lesion size (≤ 5 mm, 0%; 6-9 mm, 6.0%; ≥ 10 mm, 13.6%).

CONCLUSION

The study proposes removing all SSA/Ps ≥ 6 mm in order to remove high-risk SSA/Ps-CD(+), with high sensitivity.

Dexmedetomidine for conscious sedation with colorectal endoscopic submucosal dissection: a prospective double-blind randomized controlled study

Objective

Conscious sedation for colorectal endoscopic submucosal dissection (ESD) has not been standardized, and there are no studies of sedation for colorectal ESD.

Methods

We conducted a prospective double-blind randomized controlled trial to clarify the usefulness of DEX during colorectal ESD. In total 80 patients with colorectal ESD from April 2016 to May 2017 were assigned to the placebo group or the DEX group (40 cases each). The primary outcome was patient satisfaction (visual analogue scale: VAS). Secondary outcomes were evaluated for 13 factors, including patient pain level (VAS), endoscopist satisfaction (VAS), objective patient pain level viewed from the endoscopist’s perspective (VAS), rate of patient response, rate of side effects, etc., from the patient’s and endoscopist’s perspectives.

Results

Patient satisfaction was 8.4 and 9.1 (P = 0.018) in the placebo group and the DEX group, respectively. Secondary outcomes of patient pain level, endoscopist satisfaction, objective patient pain level from the endoscopist’s perspective for the placebo and DEX groups were 1.2 and 0.4 (P = 0.045), 8.2 and 9.3 (P < 0.001), and 1.2 and 0.5 (P = 0.002), respectively. All of these were significantly positive results (more comfortable and less pain) in the DEX group. The rate of a patient response was 100% in all cases. The side effects (hypoxia/bradycardia/hypotension) were 0%/0%/0% and 7.5%/7.5%/5% (P = 0.030). However, these rates were less than the reported side effect occurrence rate, and no additional medication was needed.

Conclusion

DEX enables conscious sedation, and is useful not only for patient and endoscopist satisfaction but also for pain relief. DEX is an effective sedation method for colorectal ESD.

Subtypes of the Type II Pit Pattern Reflect Distinct Molecular Subclasses in the Serrated Neoplastic Pathway

BACKGROUND

Colorectal serrated lesions (SLs) are important premalignant lesions whose clinical and biological features are not fully understood.

AIMS

We aimed to establish accurate colonoscopic diagnosis and treatment of SLs through evaluation of associations among the morphological, pathological, and molecular characteristics of SLs.

METHODS

A total of 388 premalignant and 18 malignant colorectal lesions were studied. Using magnifying colonoscopy, microsurface structures were assessed based on Kudo's pit pattern classification system, and the Type II pit pattern was subcategorized into classical Type II, Type II-Open (Type II-O) and Type II-Long (Type II-L). BRAF/KRAS mutations and DNA methylation of CpG island methylator phenotype (CIMP) markers (MINT1, - 2, - 12, - 31, p16, and MLH1) were analyzed through pyrosequencing.

RESULTS

Type II-O was tightly associated with sessile serrated adenoma/polyps (SSA/Ps) with BRAF mutation and CIMP-high. Most lesions with simple Type II or Type II-L were hyperplastic polyps, while mixtures of Type II or Type II-L plus more advanced pit patterns (III/IV) were characteristic of traditional serrated adenomas (TSAs). Type II-positive TSAs frequently exhibited BRAF mutation and CIMP-low, while Type II-L-positive TSAs were tightly associated with KRAS mutation and CIMP-low. Analysis of lesions containing both premalignant and cancerous components suggested Type II-L-positive TSAs may develop into KRAS-mutated/CIMP-low/microsatellite stable cancers, while Type II-O-positive SSA/Ps develop into BRAF-mutated/CIMP-high/microsatellite unstable cancers.

CONCLUSIONS

These results suggest that Type II subtypes reflect distinct molecular subclasses in the serrated neoplasia pathway and that they could be useful hallmarks for identifying SLs at high risk of developing into CRC.

Recurrence rate of lateral margin-positive cases after en bloc endoscopic submucosal dissection of colorectal neoplasia

PURPOSE

We aimed to evaluate the recurrence rate of colorectal neoplasia showing histologic lateral margin involvement after en bloc endoscopic submucosal dissection (ESD).

METHODS

We reviewed 527 colorectal lesions that were removed by en bloc ESD from 2005 to 2013 and followed by endoscopy. Based on the postprocedural pathologic reports, the lesions were categorized as follows: lesions with clear deep and positive lateral margins (n = 63) and lesions with R0 resection (n = 299).

RESULTS

The tumor size was 45.7 ± 21.1 mm in the lateral margin-positive group and 30.6 ± 15.1 in the R0 group (P < 0.001). Procedure time was longer in the lateral margin-positive group than in the R0 group (94.3 ± 75.1 vs. 54.1 ± 48.9 min; P < 0.001). Lateral margin positivity was associated with ESD time ≥ 120 min in the multivariate analysis. Compared with 0-I morphology, LST-G was significantly associated with the lateral margin positivity. The volume of ESD experience in endoscopists may also be associated with the lateral margin positivity. Histologic reassessment of the specimen suggested that 32.2% of lateral margin-positive cases based on the initial pathology report were false-positive lateral margin involvement. The 5-year cumulative recurrence rate was 0.6% in the R0 group and 5% in the margin-positive group (P = 0.198).

CONCLUSIONS

The local recurrence rate was not higher in lateral margin-positive cases than in R0 resection cases if the colorectal epithelial neoplasia was removed in an en bloc manner using ESD. Meticulous pathologic interpretation may reduce unnecessarily frequent surveillance after en bloc ESD.

Single-center implementation of endoscopic submucosal dissection (ESD) in the colorectum: Low recurrence rate after intention-to-treat ESD

BACKGROUND AND AIM

Colorectal endoscopic submucosal dissection (ESD) shows higher R0 resection and lower local recurrence rates than endoscopic mucosal resection (EMR) in Japan. In Europe, independent learning of ESD in the colorectum is feasible, but yet to be analyzed for curative resection and recurrence rates.

METHODS

After experimental training under supervision by Japanese experts (T.O., N.Y.), three endoscopists independently carried out 83 ESD procedures intention-to-treat for lesions in the entire colorectum of 67 patients in a prospective registry (November 2009 to June 2016).

RESULTS

ESD was feasible in 80 (96%) colorectal neoplasias (mean diameter 33.6 [± 1.8] mm), and three more required conversion to piecemeal EMR. The lesions were adenomas in 66% with low-grade intraepithelial neoplasia (LGIN), 29% with high-grade intraepithelial neoplasia, and 5% with carcinomas (G2, pT1). ESD had to be facilitated by the final use of snaring (hybrid-ESD, n = 45), especially in the initial learning period. En-bloc resection rate was 85%. Complications were microperforations (7%, conducive to one hemicolectomy), and delayed bleeding (1%) without mortality or long-term morbidity. Residual adenomas with LGIN (5%) after hybrid-ESD did not recur after endoscopic ablation. All malignant neoplasias (34%) were curatively resected without recurrence after a mean follow up of 19.5 (± 3.2) months.

CONCLUSIONS

During independent ESD learning in the colorectum, ESD intention-to-treat showed a low recurrence rate after appropriate training, and hybrid-ESD showed acceptable complication and recurrence rates, justifying hybrid-ESD as a strategy for self-completion and rescue.

Advances in CRC Prevention: Screening and Surveillance

Colorectal cancer (CRC) is among the most commonly diagnosed cancers and causes of death from cancer across the world. CRC can, however, be detected in asymptomatic patients at a curable stage, and several studies have shown lower mortality among patients who undergo screening compared with those who do not. Using colonoscopy in CRC screening also results in the detection of precancerous polyps that can be directly removed during the procedure, thereby reducing the incidence of cancer. In the past decade, convincing evidence has appeared that the effectiveness of colonoscopy as CRC prevention tool is associated with the quality of the procedure. This review aims to provide an up-to-date overview of recent efforts to improve colonoscopy effectiveness by enhancing detection and improving the completeness and safety of resection of colorectal lesions.

Randomised controlled trial of transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND Study)

OBJECTIVE

Non-randomised studies suggest that endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM), but EMR might be more cost-effective and safer. This trial compares the clinical outcome and cost-effectiveness of TEM and EMR for large rectal adenomas.

DESIGN

Patients with rectal adenomas ≥3 cm, without malignant features, were randomised (1:1) to EMR or TEM, allowing endoscopic removal of residual adenoma at 3 months. Unexpected malignancies were excluded postrandomisation. Primary outcomes were recurrence within 24 months (aiming to demonstrate non-inferiority of EMR, upper limit 10%) and the number of recurrence-free days alive and out of hospital.

RESULTS

Two hundred and four patients were treated in 18 university and community hospitals. Twenty-seven (13%) had unexpected cancer and were excluded from further analysis. Overall recurrence rates were 15% after EMR and 11% after TEM; statistical non-inferiority was not reached. The numbers of recurrence-free days alive and out of hospital were similar (EMR 609±209, TEM 652±188, p=0.16). Complications occurred in 18% (EMR) versus 26% (TEM) (p=0.23), with major complications occurring in 1% (EMR) versus 8% (TEM) (p=0.064). Quality-adjusted life years were equal in both groups. EMR was approximately €3000 cheaper and therefore more cost-effective.

CONCLUSION

Under the statistical assumptions of this study, non-inferiority of EMR could not be demonstrated. However, EMR may have potential as the primary method of choice due to a tendency of lower complication rates and a better cost-effectiveness ratio. The high rate of unexpected cancers should be dealt with in further studies.

Underwater endoscopic colorectal polyp resection: Feasibility in everyday clinical practice

BACKGROUND

Endoscopic mucosal resection is well-established for resecting flat or sessile benign colon polyps. The novel underwater endoscopic mucosal resection eschews submucosal injection prior to endoscopic mucosal resection. Reports about underwater endoscopic mucosal resection were limited to small series of single and/or tertiary-care referral centers, with single or supervised operators.

OBJECTIVE

The purpose of this study was to determine feasibility and efficacy of underwater resection of polyps of any morphology (underwater polypectomy, here includes underwater endoscopic mucosal resection) in routine clinical practice.

METHODS

This study involved a comparison of colonoscopy records of two community hospitals (January 2015-December 2016) for underwater polypectomy (n = 195) and gas insufflation polypectomy (n = 186).

RESULTS

Comparable demographics, procedural data, overall distribution, morphology and size of resected lesions, number of en bloc and R0 resections (any polyp morphology and size); exception: overall, underwater polypectomy pedunculated polyps were significantly larger than those in the gas insufflation polypectomy group, p = 0.030. Underwater polypectomy (median, min) resection time was significantly shorter than gas insufflation polypectomy: sessile and flat polyps 6-9 mm, 0.8 vs 2.7 (p = 0.040); 10-19 mm, 2.0 vs 3.3 (p = 0.025), respectively; pedunculated polyps 6-19 mm, 0.8 vs 3.3 (p < 0.001). Underwater polypectomy resection of pedunculated polyps 6-19 mm showed significantly less immediate bleeding: 11.1% vs 1.5%, respectively (p = 0.031).

CONCLUSIONS

Underwater polypectomy can be efficaciously used in routine clinical practice for the complete resection of colon polyps, with several advantages over gas insufflation polypectomy.

The occurrence and characteristics of endoscopically unexpected malignant degeneration in large rectal adenomas

BACKGROUND AND AIMS

Large non-pedunculated rectal polyps are most commonly resected by endoscopic mucosal resection (EMR) or transanal endoscopic microsurgery (TEM). Despite pre-procedural diagnostics, unexpected rectal cancer is incidentally encountered within the resected specimen. This study aimed to compare the diagnostic assessment and procedural characteristics of lesions with and without unexpected submucosal invasion.

METHODS

A post-hoc analysis of a multicenter randomized trial (TREND study) was performed in which patients with a non-pedunculated rectal polyp of ≥3 cm without endoscopic suspicion of invasive growth were randomized between EMR and TEM.

RESULTS

Unexpected rectal cancer was detected in 13% (27/203) of patients; 15 after EMR and 12 after TEM. Most consisted of low-risk T1 cancers (78%, n = 18). There were no differences in the diagnostic assessment between lesions with and without unexpected submucosal invasion. Diagnostic biopsies revealed similar rates of high-grade dysplasia (28% [7/25] vs 18% [26/144]). When compared with EMR of adenomas, EMR procedures of unexpected cancers had a lower success rate of submucosal lifting (60% vs 93%, P < .001), were more often assessed as endoscopically incomplete (33% vs 10%, P = .01), and were more frequently terminated prematurely (60% vs 8%, P = .001).

CONCLUSIONS

Diagnostic assessment of large non-pedunculated rectal polyps revealed similar characteristics between unexpected cancers and adenomas. Unexpected cancers during EMR were non-lifting in 40%, endoscopically assessed as incomplete in 33%, and terminated prematurely in 60%. In treatment-naive patients, these factors should raise suspicion of malignancy and need discussion in a multidisciplinary team meeting for decision on further treatment strategies.