Clinical usefulness of the hold-and-drag closure using the SB clip for large mucosal defects after colorectal endoscopic submucosal dissection.

BACKGROUND: Endoscopic clip closure of mucosal defects after colorectal endoscopic submucosal dissection (ESD) reduces the risk of postoperative adverse events, but achieving complete closure for large mucosal defects can be difficult. The aim of this study was to evaluate the effectiveness of the hold-and-drag closure using an SB clip compared with that of the conventional closure for mucosal defects after colorectal ESD. METHODS: Eighty-four consecutive colorectal lesions resected by ESD at the Hiroshima Asa Citizens Hospital were registered and randomly allocated to two groups (Group A: SB clip, Group B: EZ clip), and then endoscopic closures were performed. We crossed-over to the SB clip in situations where the initial closure using an EZ clip was unsuccessful in achieving complete closure. Outcomes were compared and analyzed. RESULTS: Forty-two lesions were randomly assigned to groups A and B. The complete closure rate was significantly higher in group A, especially in resected specimens with a diameter of 30 mm or more. Twelve lesions that failed complete closure in group B were changed to SB clips, and 95% of the whole of group B were successfully closed. There were no significant differences in procedural time, number of clips, and cost of clips between groups A and B. CONCLUSION: Compared with the conventional closure, the hold-and-drag closure using an SB clip is a more suitable method for complete closure, especially for large mucosal defects of 30 mm or more. Furthermore, this is a simpler and more economical compared to a zipper closure using EZ clips.

Optimal candidates for early colonoscopy in the management of acute lower gastrointestinal bleeding.

BACKGROUND AND AIM: Early colonoscopy has not shown any advantages over elective colonoscopy in reducing the risk of early rebleeding (≤ 30 days) after acute lower gastrointestinal bleeding (ALGIB). Considering the heterogeneity among patients with ALGIB, we sought to evaluate appropriate candidates for early colonoscopy. METHODS: A total of 592 patients with ALGIB were enrolled, and the clinical outcomes of early colonoscopy were investigated. Thereafter, the participants were divided into two groups: the recent bleeding group (n = 445), with hematochezia 0-6 h before hospital arrival, and non-recent bleeding group (n = 147). The clinical outcomes yielded by early colonoscopy were assessed in each group. RESULTS: The multivariate analysis including the entire population revealed that early colonoscopy (< 24 h) did not reduce the risk of early rebleeding (adjusted odds ratio [AOR], 0.88; 95% confidence interval [CI], 0.55-1.39). However, in the subgroup analysis, early colonoscopy independently reduced the risk of early rebleeding in the recent bleeding group (AOR, 0.56; 95% CI, 0.33-0.94). Moreover, a reduction in the need for radiological or surgical intervention (AOR, 0.34), transfusion (AOR, 0.62), and prolonged hospitalization (AOR, 0.42), as well as improvement in diagnostic yield (AOR, 1.78) and endoscopic treatment rates (AOR, 1.66), were observed. Early colonoscopy did not improve the outcomes of the non-recent bleeding group. CONCLUSIONS: Early colonoscopy is not required for all patients with ALGIB. However, it may be suitable for those with hematochezia 0-6 h before hospital arrival, as it reduces early rebleeding and improves clinical outcomes.

A pilot study to evaluate the effectiveness and safety of urgent endoscopy for gastroduodenal perforation.

BACKGROUND: Gastroduodenal perforation is potentially life threatening and requires early diagnosis and treatment. Urgent endoscopy facilitates detecting bleeding sites and achieving hemostasis. However, there is no consensus on urgent endoscopy for gastroduodenal perforation in Japan. METHODS: We evaluated the effectiveness and safety of urgent endoscopy for gastroduodenal perforation. We compared clinical characteristics between 140 patients who underwent urgent endoscopy (urgent endoscopy group) and 16 patients did not (no urgent endoscopy group) at Hiroshima City Asa Citizens Hospital between December 2005 and December 2018. RESULTS: Endoscopic diagnosis was possible in all urgent endoscopy group. In contrast, correct diagnosis of the perforation site was made on CT in 99 cases (63%). Furthermore, the proportion of cases with correct diagnosis of the perforation site by CT findings differed significantly between the urgent endoscopy group and the no urgent endoscopy group (66% vs. 38%, p < 0.05). No complications of urgent endoscopy were observed. Primary perforation site was gastric in 42 cases and duodenal in 114. In the 42 gastric perforation cases, 12 gastric perforation cases (29%) were managed conservatively, successfully in 9 (75%); 2 cases (17%) required delayed emergency surgery for worsening peritonitis. In the 114 duodenal perforation cases (duodenal ulcer in all cases), 52 cases (46%) were managed conservatively, successfully in 48 (92%); 3 cases (6%) required delayed emergency surgery for worsening peritonitis. A significantly higher proportion of gastric perforation cases than duodenal perforation cases required surgical treatment (76% vs. 57%, p < 0.05). Multivariate analysis revealed localized abdominal pain (no peritonism) (OR 0.25; 95% CI 0.08-0.75; p < 0.01) and perforation diameter ≤ 5 mm (OR 0.13; 95% CI 0.04-0.36; p < 0.01) as significant independent clinical factors for successful conservative management of duodenal ulcer perforation. CONCLUSIONS: Urgent endoscopy in gastroduodenal perforation enabled primary diagnosis and perforation site identification, and facilitated deciding the management strategy.

[Two rare cases of severe hyponatremia with consciousness disorder following bowel preparation and high fluid intake].

Symptomatic hyponatremia due to bowel preparation is extremely rare, but it can cause severe neurological symptoms and require hospitalization. We report our experience with two cases of symptomatic hyponatremia after bowel preparation. Our findings suggest that the cause of hyponatremia may be not only oral bowel cleansing agents but also high fluid intake. Adjusting the dose and pace of oral bowel cleansing agents and fluid intake;rehydration should be considered to prevent any recurrences.

Clinical significance of immunohistochemical lymphovascular evaluation to determine additional surgery after endoscopic submucosal dissection for colorectal T1 carcinoma.

PURPOSE: The Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines indicate lymphovascular invasion-evaluated by hematoxylin and eosin (HE) staining-as a surgical requirement after endoscopic submucosal dissection (ESD) in T1 colorectal carcinoma (CRC) patients; however, immunohistochemical evaluation may be superior. This study aimed to clarify the significance of immunohistochemical lymphovascular evaluation as an indicator for additional surgery of T1 CRC after ESD, and assessed the guidelines' adequacy, even when evaluating through immunostaining. METHODS: Patients with T1 CRC who underwent ESD were enrolled across three institutions between January 2012 and December 2017. Immunohistochemical lymphovascular evaluation was performed. Clinicopathological features, pathological evaluations, and surgery indications were recorded. Univariate and multivariate logistic regression identified risk factors for lymph node (LN) metastasis of T1 CRC after ESD. RESULTS: Among 370 patients with T1 CRC, recurrence, 5-year overall survival, and 5-year disease specific survival rates were 1.6%, 94.6%, and 99.5%, respectively. Six patients (1.6%) experienced recurrence, five of whom underwent additional surgery. Those with no risk factors did not exhibit recurrence. A total of 215 (58.1%) patients underwent additional surgery after ESD, 21 (9.7%) of whom exhibited LN metastasis. Among 16 patients who underwent additional surgery due to lymphovascular invasion, three (18.8%) had LN metastasis. Multivariate logistic regression analysis identified lymphatic invasion as a significant risk factor for LN metastasis (odds ratio 3.9, 95% confidence interval 1.0-14.6, P = 0.0421). CONCLUSIONS: The JSCCR guidelines have clinical validity, and immunohistochemical lymphatic evaluation findings potentially predict LN metastasis for T1 CRC after ESD.

Bile pigment in small-bowel water content may reflect bowel habits: a retrospective analysis of a capsule endoscopy imaging series.

BACKGROUND: Pigmented bile salts darken the small-bowel lumen and are present with bile acid, which is involved in the development of bowel habits. The small-bowel water content (SBWC) in the ileum could represent the colonic environment, but no studies have focused on this feature. However, measurement of crude SBWC can be challenging because of the technical difficulty of the endoscopic approach without preparation. Our aim was to evaluate optically active bile pigments in the SBWC of patients with abnormal bowel habits using capsule endoscopy (CE) to investigate the impact of bile acid on bowel habits. METHODS: The study population included 37 constipated patients, 20 patients with diarrhea, and 77 patients with normal bowel habits who underwent CE between January 2015 and May 2018. Patients with secondary abnormal bowel habits were excluded. In addition to conventional imaging, we used flexible spectral imaging color enhancement (FICE) setting 1 imaging, in which the effects of bile pigments on color are suppressed. Intergroup color differences of SBWC in the ileum (ΔE) were evaluated from conventional and FICE setting 1 images. Color values were assessed using the CIE L*a*b* color space. Differences in SBWC lightness (black to white, range 0-100) were also evaluated. RESULTS: The ΔE values from the comparison of conventional images between patients with constipation and with normal bowel habits and between patients with diarrhea and with normal bowel habits were 12.4 and 11.2, respectively. These values decreased to 4.4 and 3.3, respectively, when FICE setting 1 images were evaluated. Patients with constipation and diarrhea had significantly brighter (34.4 versus 27.6, P < .0001) and darker (19.6 versus 27.6, P < .0001) SBWC lightness, respectively, than patients with normal bowel habits. The FICE setting 1 images did not reveal significant differences in SBWC lightness between those with constipation and with normal bowel habits (44.1 versus 43.5, P = .83) or between those with diarrhea and with normal bowel habits (39.1 versus 43.5, P = .20). CONCLUSIONS: Differences in SBWC color and darkness in the ileum appear to be attributable to bile pigments. Therefore, bile pigments in SBWC may reflect bowel habits.

Management and risk factors for incomplete resection associated with jumbo forceps polypectomy for diminutive colorectal polyps: a single-institution retrospective study.

BACKGROUND: Cold forceps polypectomy is simple and widely used in clinical practice. However, there are concerns about the risk of incomplete resection using this technique. In recent years, it has been reported that polypectomy with jumbo forceps (JF) is an effective treatment modality for diminutive polyps (DPs) because JF are able to remove large tissue samples with the combined advantage of a higher complete histological resection rate for DPs than standard forceps. To our knowledge, no studies have evaluated the risk factors for incomplete resection when polypectomy with JF is performed for DPs. METHODS: From among 1129 DPs resected using JF at Hiroshima City Asa Citizens Hospital between November 2015 and December 2016, we retrospectively evaluated the clinical outcomes of 999 tumors with known histopathology and investigated the relationship between incomplete resection and clinicopathological factors. RESULTS: Most lesions [985 (87%)] were low-grade dysplasia and 14 (1%) were high-grade dysplasia. The en bloc resection rate was 92% (918/999) and the histological en bloc resection rate was 78% (777/999). Multivariate analysis showed that the significant independent predictors of incomplete resection were tumor size ≥ 4 mm [odds ratio (OR) 3.8; 95% confidence interval (CI) 2.65-5.37; p < 0.01], non-tangential direction of forceps in relation to the tumor (OR 1.73; 95% CI 1.21-2.45; p < 0.01), and lack of muscularis mucosae in the pathological specimen (OR 15.7; 95% CI 9.16-27.7; p < 0.01). CONCLUSIONS: This study identified significant independent predictors of incomplete resection of DPs which may be helpful when planning polypectomy with JF.

[A case of ruptured posterior superior pancreaticoduodenal artery aneurysm successfully treated by emergency transcatheter embolization].

A man in his 40s with no remarkable past medical history was referred to our hospital with acute exacerbation of nonspecific epigastric pain by another hospital on the morning of the day of presentation. Though vital signs were stable, tenderness and guarding were observed over the entire abdomen. Contrast-enhanced computed tomography (CT) revealed a giant retroperitoneal hematoma due to a ruptured aneurysm close to the superior mesenteric artery. Emergency angiography of the superior mesenteric artery detected a ruptured 2-mm pseudoaneurysm of the posterior superior pancreaticoduodenal artery, for which embolization was immediately performed. The postoperative course was good, with the patient complaining only of transient abdominal pain due to exclusion of the hematoma on hospital day 6. His clinical symptoms disappeared with conservative treatment, and the patient was discharged on hospital day 18. Complete occlusion of the aneurysm and reduction of the hematoma was confirmed on follow-up CT. Pancreaticoduodenal artery aneurysm is an uncommon visceral artery aneurysm, and ruptured aneurysms typically result in fatal hemorrhage and high mortality. We herein report a case of ruptured aneurysm of the posterior pancreaticoduodenal artery where emergency transcatheter arterial embolization was able to save the patient's life. We also review 116 cases of pancreaticoduodenal artery aneurysm reported in Japanese literature.

Arteriosclerosis Is a Major Predictor of Small Bowel Vascular Lesions.

BACKGROUND: Most studies have focused on evaluating the association between the presence of small bowel vascular lesions (SBVLs) and patients' comorbidities. AIMS: We sought to uncover a more fundamental indicator that may predict the presence of SBVLs by considering atherosclerosis qualitatively and quantitatively. METHODS: We enrolled 79 consecutive patients with obscure gastrointestinal bleeding who had undergone computed tomography (CT) and capsule endoscopy or double-balloon endoscopy from January 2015 to June 2017. The SBVL frequency, type, and location, and the relationship between the presence of SBVLs and the patients' clinical characteristics were evaluated. Arterial wall calcification was assessed on unenhanced CT images, and a modified Agatston scoring system was used to determine the abdominal aorta calcium scores. RESULTS: Of the 27 (34%) patients with SBVLs, 15 (19%) had type 1a, 12 (15%) had type 1b, and 2 (3%) had type 2a SBVLs. Most of the lesions were located in the jejunum. Cardiovascular disease (P = .017), chronic kidney disease (P = .025), and arteriosclerosis (P = .0036) were associated with the presence of SBVLs. Subsequent multivariate analysis revealed that arteriosclerosis (odds ratio [OR] 7.29; 95% confidence interval [CI] 1.13-143.9) and superior mesenteric artery calcification (OR 16.3; 95% CI 3.64-118.6) were independent predictors of the presence of SBVLs. The modified Agatston score was significantly higher in SBVL cases than in non-SBVL cases (6384 vs. 2666, P = .0023). CONCLUSIONS: Arteriosclerosis, especially increased superior mesenteric artery calcification, is associated with an increased likelihood of SBVLs.

Long-term outcomes after endoscopic submucosal dissection for superficial colorectal tumors.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) is an effective procedure for en bloc resection of superficial colorectal tumors regardless of tumor size or location. However, there are few reports on long-term outcomes for patients with superficial colorectal tumors after ESD. We therefore aimed to evaluate the long-term outcomes after ESD for superficial colorectal tumors. METHODS: ESD was performed on 257 colorectal tumors in 255 consecutive patients at Hiroshima University Hospital between June 2003 and July 2010. We investigated the following variables: patient characteristics, the American Society of Anesthesiologists score, tumor location, tumor size, growth type, histology, en bloc resection rate, achievement of curative resection, procedure time, and adverse events. The 5-year overall survival (OS), 5-year disease-specific survival (DSS), local recurrence, and metachronous tumor occurrence were also analyzed. RESULTS: We identified 224 tumors in 222 patients who were confirmed dead or had follow-up data for more than 5 years. After a median follow-up of 79 months, 5-year OS and DSS rates were 94.6% and 100%, respectively. The local recurrence rate (1.5%) was significantly higher in patients undergoing piecemeal resection (9.1%) compared with en bloc resection (0.6%), in cases of histologic incomplete resection compared with complete resection, and in cases of non-R0 resection compared with R0 resection. The rates of total number of tumors (≥6 mm) and carcinoma metachronous tumors after ESD without additional surgical resection were 18.9% (38/201) and 4.0% (8/201), respectively. CONCLUSIONS: Long-term outcomes after ESD for superficial colorectal tumors are favorable. Patients should be surveyed for both local recurrence and metachronous tumors after ESD.

Clinical impact and characteristics of the narrow-band imaging magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

BACKGROUND AND AIMS: The Japan NBI Expert Team (JNET) was established in 2011 and has proposed a universal narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors. The aim of this study was to evaluate the clinical usefulness of the JNET classification for colorectal lesions. METHODS: We analyzed 2933 colorectal lesions, which were diagnosed by NBI magnifying observation before endoscopic treatment or surgery. The colorectal lesions consisted of 136 hyperplastic polyps/sessile serrated polyps (HPs/SSPs), 1926 low-grade dysplasia (LGD), 571 high-grade dysplasia (HGD), 87 superficial submucosal invasive (SM-s) carcinomas, and 213 deep submucosal invasive (SM-d) carcinomas. We evaluated the relationship between the JNET classification and the histologic findings of these lesions. RESULTS: The sensitivity, specificity, positive and negative predictive values, and accuracy of Type 1 lesions for the diagnosis of HP/SSP were, respectively, 87.5%, 99.9%, 97.5%, 99.4%, and 99.3%; of Type 2A lesions for the diagnosis of LGD were 74.3%, 92.7%, 98.3%, 38.7%, and 77.1%; of Type 2B lesions for the diagnosis of HGD/SM-s carcinoma were 61.9%, 82.8%, 50.9%, 88.2%, and 78.1%; for Type 3 lesions for the diagnosis of SM-d carcinoma were 55.4%, 99.8%, 95.2%, 96.6%, and 96.6%, respectively. CONCLUSIONS: Types 1, 2A, and 3 of the JNET classification were very reliable indicators for HP/SSP, LGD, and SM-d carcinoma, respectively. However, the specificity and positive predictive value of Type 2B were relatively lower than those of others. Therefore, an additional examination such as pit pattern diagnosis using chromoagents is necessary for accurate diagnosis of Type 2B lesions.

Long-term outcomes after treatment for T1 colorectal carcinoma.

PURPOSE: Long-term outcomes of patients with T1 colorectal carcinoma (CRC) treated by endoscopic resection (ER) or surgical resection are unclear in relation to the curative criteria in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines. The aim of this study was to retrospectively compare the long-term outcomes among patients with T1 CRC in relation to the treatment methods. METHODS: We examined 322 T1 CRC cases treated between January 1992 and August 2008 at Hiroshima University Hospital. Patients who did not meet the curative criteria in the JSCCR guidelines were defined as "non-endoscopically curable" and classified into three groups: underwent ER alone (group A: 45 patients), underwent additional surgery after ER (group B: 106 patients), and underwent surgical resection alone (group C: 92 patients). RESULTS: Of the 322 T1 CRC patients, 79 were categorized as endoscopically curable and 243 as non-endoscopically curable. Among the endoscopically curable T1 CRC patients, recurrence and 5-year OS rates were 0 and 94.2%, respectively. In groups A, B, and C, recurrence rates were 4.4, 6.6, and 4.3%, and OS rates were 85.6, 95.1, and 96.3%, respectively (p < 0.05). Local recurrence or distant/lymph node metastasis was observed in 13 patients (group A: 2; group B: 7; group C: 4). Death due to primary CRC occurred in six patients (group B: 4; group C: 2). CONCLUSION: Long-term outcomes support the curative criteria according to the JSCCR guidelines. ER for T1 CRC did not worsen clinical outcomes in cases that required additional surgical resection.

Clinical significance and validity of the subclassification for colorectal laterally spreading tumor granular type.

BACKGROUND AND AIM: Colorectal laterally spreading tumor granular type (LST-G) is generally divided into two subtypes based on morphology. Here, we retrospectively investigated the clinical significance of a concrete, objective LST-G subclassification. METHODS: This study examined 636 consecutive cases that were resected endoscopically or surgically. LST-G was subclassified as follows: Type 1, a lesion with homogenous uniform granules with uniform (<5 mm) nodules; Type 2, a lesion with granules and small nodules (≥5 mm, <10 mm); or Type 3, a lesion accompanied by large nodules (≥10 mm). For the validation study, 194 images were compiled from 97 cases investigated using conventional colonoscopy and chromoendoscopy with indigo carmine dye spraying. Images were distributed in a randomized order to students without prior endoscopy experience, less-experienced endoscopists (LEE group), and highly experienced endoscopists (HEE group). Diagnostic accuracy and interobserver agreement were then evaluated. RESULTS: There was no submucosal invasion in Type 1 lesions. The incidence of deep submucosal invasive carcinoma was higher for Type 3 lesions than for Type 2 lesions. Interobserver agreement was good in each group. Diagnostic accuracy was higher in the HEE group than in the student and LEE groups. Chromoendoscopy had a higher accuracy rate than conventional colonoscopy in the LEE and HEE groups (LEE, 0.74 vs 0.69, P < 0.05; HEE, 0.84 vs 0.78, P < 0.05). CONCLUSIONS: This subclassification of LST-G according to the diameters of granules and nodules was both useful for choosing therapeutic strategies in the clinical setting and universally applicable.

Endoscopic submucosal dissection for anorectal tumor with hemorrhoids close to the dentate line: a multicenter study of Hiroshima GI Endoscopy Study Group.

BACKGROUND: The lower rectum close to the dentate line has distinct characteristics, making endoscopic submucosal dissection (ESD) of tumors challenging. We assessed clinical outcomes of ESD for such patients with hemorrhoids. METHODS: Sixty-four patients (mean age, 68 years) underwent ESD for anorectal tumors close to the dentate line. We divided patients into those with (Group A, 45 patients) and without hemorrhoids (Group B, 19 patients). We examined en bloc and histological en bloc resection rates, procedure time, complication rates, and postoperative prognosis after ESD. RESULTS: The mean tumor size was 43 mm. Histologic diagnoses were adenoma (42 %, 27/64), carcinoma in situ (44 %, 28/64), and T1 carcinoma (14 %, 9/64). There was no significant difference in en bloc resection (93 %, 42/45 vs. 95 %, 18/19) or postoperative bleeding rates (16 %, 7/45 vs. 11 %, 2/19) between Groups A and B, respectively. The mean procedural durations were 120 and 124 min, respectively, in Groups A and B. No perforations occurred. There was no significant difference in postoperative anal pain rate between Groups A (18 %, 8/45) and B (16 %, 3/19), and it resolved within a few days in all cases. There was one case of stricture in Group B. Two patients with T1 carcinoma underwent additional surgery, one underwent chemotherapy, and five had no additional treatment. No recurrence occurred during the follow-up period of 38 months. CONCLUSIONS: ESD is safe and effective for anorectal tumors close to the dentate line in patients with hemorrhoids.

Risk of lymph node metastasis in colorectal T1 (SM) carcinoma.

In this report, we reviewed risk factors for lymph node metastasis in colorectal T1 (SM) carcinoma in relation to the chronological trend of the management of T1 colorectal carci- noma after endoscopic treatment. Recently according to the accumulation of many cases and detailed pathologic evaluation, after complete endoscopic en bloc resection, if below all conditions are satisfied in histological examination, 1) submucosal invasion depth: less than 1,000 pm, 2)histologic grade: favorable, 3)no vessel involvement and 4)budding grade: low, it shows very low risk of lymph node metastasis. Also, in this report, we assess the conditions for additional surgery after endoscopic resection based on the risk stratification of lymph node metastasis.

Endoscopic submucosal dissection as total excisional biopsy for clinical T1 colorectal carcinoma.

BACKGROUND/AIMS: Only the depth of submucosal invasion can be estimated prior to determining the indications for endoscopic submucosal dissection (ESD) as a curative treatment for colorectal carcinoma (CRC). Here we evaluated the outcomes of ESD for clinical T1 CRCs. METHODS: Of 660 patients who underwent ESD for CRC at the Hiroshima University Hospital between June 2003 and December 2013, we examined the outcomes of 37 (6%; 26 men, 11 women; mean age ± SD, 68 ± 12 years) who underwent ESD as total excisional biopsy for various reasons, in spite of an endoscopic diagnosis of T1 CRC. RESULTS: The mean lesion size was 25 ± 14 mm; 14 lesions were protruding and 23 were superficial. The en bloc resection rate was 100% (37/37). The histological en bloc resection rate was 92% (34/37). ESD resulted in a positive vertical margin in 3 cases. Deep submucosal invasion was seen in 3 cases, 2 of which had severe submucosal fibrosis. Although severe submucosal fibrosis was not found in other cases, pathologic examination of the deepest invasive portion of the tumor revealed poorly differentiated adenocarcinoma. The rates of post-ESD bleeding and perforation were 8% (3/37) and 5% (2/37), respectively. All patients recovered under conservative therapy. No cases of recurrence were noted in patients without additional surgical resection when the lesions satisfied the curative conditions listed in the 2014 Japanese Society for Cancer of the Colon and Rectum guidelines. CONCLUSION: En bloc resection by ESD as total excisional biopsy for clinical T1 CRC is a highly effective treatment and establishes a precise histological diagnosis.

Towards safer and appropriate application of endoscopic submucosal dissection for T1 colorectal carcinoma as total excisional biopsy: future perspectives.

According to the Japanese Society for Cancer of the Colon and Rectum Guidelines 2014 for the Treatment of Colorectal Cancer, cases with T1 colorectal carcinoma should be considered for additional colectomy with lymph node dissection when histologically complete en bloc resection is endoscopically carried out and when one of the four risk factors listed below is present. These four risk factors are: (i) submucosal (SM) invasion depth ≥1000 µm; (ii) positive vascular invasion; (iii) poorly differentiated adenocarcinoma, signet ring cell carcinoma, or mucinous carcinoma; and (iv) grade 2/3 budding at the deepest part of SM invasion. However, the probability of lymph node metastasis is extremely low if none of these risk factors are present, with the exception of SM invasion depth ≥1000 µm. Consequently, it is assumed that there will be an increasing number of cases where no additional surgery is done, or cases of moderate invasive carcinoma in which endoscopic treatment is carried out to achieve an excisional biopsy, for which complete resection is applicable. In these cases, the preoperative diagnosis, resection techniques such as endoscopic submucosal dissection, features of resected specimens, and the accuracy of pathological diagnosis are all extremely important.