An Analysis of Delayed Bleeding in Cases of Colorectal Endoscopic Submucosal Dissection Due to Types of Direct Oral Anticoagulants in Japan.

BACKGROUND & AIMS: Reported rates of delayed bleeding (DB) after endoscopic resection using direct oral anticoagulants (DOACs) are high and heterogeneous. This large-scale multicenter study analyzed cases of DB after colorectal endoscopic submucosal dissection related to various types of DOACs in Japan (the ABCD-J study) with those associated with warfarin. METHODS: We retrospectively reviewed 1019 lesions in patients treated with DOACs and 459 lesions in patients treated with warfarin among 34,455 endoscopic submucosal dissection cases from 47 Japanese institutions between 2012 and 2021. The DB rate (DBR) with each DOAC was compared with that with warfarin. Risk factors for DB in patients treated with DOACs or warfarin were also investigated. RESULTS: The mean tumor sizes in the DOAC and warfarin groups were 29.6 ± 14.0 and 30.3 ± 16.4 mm, respectively. In the DOAC group, the DBR with dabigatran (18.26%) was significantly higher than that with apixaban (10.08%, P = .029), edoxaban (7.73%, P = .001), and rivaroxaban (7.21%, P < .001). Only rivaroxaban showed a significantly lower DBR than warfarin (11.76%, P = .033). In the multivariate analysis, heparin bridging therapy (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.27-3.73, P = .005), rectal location (2.01, 1.28-3.16, P = .002), and procedure time ≥55 minutes (2.43, 1.49-3.95, P < .001) were significant risk factors for DB in the DOAC group. The DB risk in the DOAC group (OR, (95% CI)) was 2.13 (1.30-3.50) and 4.53 (2.52-8.15) for 1 and 2 significant risk factors, respectively. CONCLUSIONS: Dabigatran was associated with a higher DBR than other DOACs, and only rivaroxaban was associated with a significantly lower DBR than warfarin.

Multicenter prospective randomized controlled clinical trial comparing the pocket-creation method with and without single-clip traction of colonic endoscopic submucosal dissection.

BACKGROUND: The pocket-creation method (PCM) was developed to overcome the technical difficulties of endoscopic submucosal dissection (ESD), although opening the pocket remains challenging. We developed a novel technique of PCM with single-clip traction (PCM-CT), which uses a reopenable clip as a traction device to maintain stability during the procedure. No prospective study has compared the efficacy of PCM-CT and PCM. This study aimed to investigate the effectiveness of PCM-CT vs. PCM in a randomized controlled trial. METHODS: This randomized controlled clinical trial was conducted at four Japanese institutions. Patients with superficial colorectal neoplastic lesions were included following Japanese guidelines for colorectal cancer. Seven moderately experienced endoscopists performed the ESD procedures using either PCM-CT or PCM. RESULTS: 100 patients were enrolled in the study. Compared with PCM, PCM-CT achieved significantly faster mean (SD) dissection speed (21.4 [10.8] vs. 27.0 [14.5] mm2/min [95%CI 0.5 to 10.7], P = 0.03), and reduced the mean procedure time (81.8 [57.9] vs. 64.8 [47.6] minutes [95%CI -38.2 to 4.3], P = 0.12) and pocket-opening time (37.8 [33.0] vs. 30.0 [28.9] minutes [95%CI -20.2 to 4.6], P = 0.22). En bloc and R0 resection rates were not significantly different between the two groups (100% vs. 100%, P >0.99; 100% vs. 96%, P = 0.50, respectively). No significant differences were observed in adverse events between the two groups. CONCLUSION: ESD facilitated by the novel PCM-CT method appeared to be significantly faster than PCM. Both methods achieved high R0 resection rates.

Computer-aided diagnosis of early-stage colorectal cancer using nonmagnified endoscopic white-light images (with videos).

BACKGROUND AND AIMS: Differentiation of colorectal cancers (CRCs) with deep submucosal invasion (T1b) from CRCs with superficial invasion (T1a) or no invasion (Tis) is not straightforward. This study aimed to develop a computer-aided diagnosis (CADx) system to establish the diagnosis of early-stage cancers using nonmagnified endoscopic white-light images alone. METHODS: From 5108 images, 1513 lesions (Tis, 1074; T1a, 145; T1b, 294) were collected from 1470 patients at 10 academic hospitals and assigned to training and testing datasets (3:1). The ResNet-50 network was used as the backbone to extract features from images. Oversampling and focal loss were used to compensate class imbalance of the invasive stage. Diagnostic performance was assessed using the testing dataset including 403 CRCs with 1392 images. Two experts and 2 trainees read the identical testing dataset. RESULTS: At a 90% cutoff for the per-lesion score, CADx showed the highest specificity of 94.4% (95% confidence interval [CI], 91.3-96.6), with 59.8% (95% CI, 48.3-70.4) sensitivity and 87.3% (95% CI, 83.7-90.4) accuracy. The area under the characteristic curve was 85.1% (95% CI, 79.9-90.4) for CADx, 88.2% (95% CI, 83.7-92.8) for expert 1, 85.9% (95% CI, 80.9-90.9) for expert 2, 77.0% (95% CI, 71.5-82.4) for trainee 1 (vs CADx; P = .0076), and 66.2% (95% CI, 60.6-71.9) for trainee 2 (P < .0001). The function was also confirmed on 9 short videos. CONCLUSIONS: A CADx system developed with endoscopic white-light images showed excellent per-lesion specificity and accuracy for T1b lesion diagnosis, equivalent to experts and superior to trainees. (Clinical trial registration number: UMIN000037053.).

Underwater endoscopic submucosal dissection for colorectal tumors decreases the incidence of post-electrocoagulation syndrome.

BACKGROUND AND AIMS: Underwater endoscopic submucosal dissection (U-ESD) is a recently developed procedure that has the potential to prevent post-ESD coagulation syndrome (PECS) owing to its heat-sink effect. We aimed to clarify whether U-ESD decreases the incidence of PECS compared with conventional ESD (C-ESD). METHODS: A total of 205 patients who underwent colorectal ESD (C-ESD: 125; U-ESD: 80) were analyzed. Propensity score matching analysis was performed to adjust for patient backgrounds. Ten C-ESD and two U-ESD patients with muscle damage or perforation during ESD were excluded when comparing PECS. The primary outcome was to compare the incidence of PECS between the U-ESD and C-ESD groups (54 matched pairs). Secondary outcomes were to compare procedural outcomes between the C-ESD and U-ESD groups (62 matched pairs). RESULTS: Among the 78 patients who underwent U-ESD, PECS occurred in only one patient (1.3%). Adjusted comparisons between the U-ESD and C-ESD groups demonstrated a significantly lower incidence of PECS in the U-ESD group (0% vs 11.1%; P = 0.027). Median dissection speed was significantly faster in the U-ESD than in the C-ESD group (10.9 mm2 /min vs 6.9 mm2 /min; P < 0.001). En bloc and complete resection rates were 100% in the U-ESD group. Although perforation and delayed bleeding occurred in one patient each (1.6%) as adverse events in the U-ESD group, there were no differences compared with the C-ESD group. CONCLUSIONS: Our study demonstrates that U-ESD effectively decreases the incidence of PECS and is a faster and safer method for colorectal ESD.

Targeted Metabolomic Profiling of Plasma Samples in Gastric Cancer by Liquid Chromatography-Mass Spectrometry.

INTRODUCTION: As the high mortality rate of gastric cancer (GC) is due to delayed diagnosis, early detection is vital for improved patient outcomes. Metabolic deregulation plays an important role in GC. Although various metabolite-level biomarkers for early detection have been assessed, there is still no unified early detection method. We conducted a plasma metabolome study to assess metabolites that may distinguish GC samples from non-GC samples. METHODS: Blood samples were collected from 72 GC patients and 29 control participants (non-GC group) at the Tokyo Medical University Hospital between March 2020 and November 2020. Hydrophilic metabolites were identified and quantified using liquid chromatography-time-of-flight mass spectrometry. Differences in metabolite concentrations between the GC and non-GC groups were evaluated using the Mann-Whitney test. The discrimination ability of each metabolite was evaluated by the area under the receiver operating characteristic curve. A radial basis function (RBF) kernel-based support vector machine (SVM) model was developed to assess the discrimination ability of multiple metabolites. The selection of variables used for the SVM utilized a step-wise regression method. RESULTS: Of the 96 quantified metabolites, 8 were significantly different between the GC and non-GC groups. Of these, N1-acetylspermine, succinate, and histidine were used in the RBF-SVM model to discriminate GC samples from non-GC samples. The area under the curve (AUC) of the RBF-SVM model was higher (0.915; 95% CI: 0.865-0.965, p < 0.0001), indicating good performance of the RBF-SVM model. The application of this RBF-SVM to the validation dataset resulted from the AUC of the RBF-SVM model was (0.885; 95% CI: 0.797-0.973, p < 0.0001), indicating the good performance of the RBF-SVM model. The sensitivity of the RBF-SVM model was better (69.0%) than those of the common tumor markers carcinoembryonic antigen (CEA) (10.5%) and carbohydrate antigen 19-9 (CA19-9) (2.86%). The RBF-SVM showed a low correlation with CEA and CA19-9, indicating its independence. CONCLUSION: We analyzed plasma metabolomics, and a combination of the quantified metabolites showed high sensitivity for the detection of GC. The independence of the RBF-SVM from tumor markers suggested that their complementary use would be helpful for GC screening.

Randomized controlled trial comparing conventional and traction endoscopic submucosal dissection for early colon tumor (CONNECT-C trial).

OBJECTIVES: Endoscopic submucosal dissection (ESD) is a widely used treatment for early gastrointestinal cancer. However, colon ESD remains challenging. Previous studies on colon ESD using the traction method used a small sample, single-center design, providing insufficient evidence of this procedure's efficacy. We thus aimed to investigate the efficacy and safety of the traction method in colon ESD in this multicenter randomized trial. METHODS: We conducted a prospective, multicenter, randomized, two-arm controlled trial at 10 facilities in Japan. A 1:1 allocation was conducted for the conventional ESD (C-ESD) and traction ESD (T-ESD) groups. The primary end-point was ESD procedure time. RESULTS: We included 128 C-ESD and 123 T-ESD cases from April 2020 to August 2021. The median procedure times for C-ESD and T-ESD were 61 (40-100) and 53 (40-76) min (P = 0.18), respectively, and no significant differences were observed between the groups. Subgroup analysis showed that the median procedure times for patients with a lesion diameter of ≥30 mm in the C-ESD and T-ESD groups were 89 (57-80) and 69 (50-104) min (P = 0.05), respectively, and for nonexpert operators were 81 (62-120) and 64 (52-109) min (P = 0.07), respectively. CONCLUSIONS: The traction method did not contribute to a significantly shortened ESD procedure time. However, this method may be useful when the tumor diameter is large or if the procedure is conducted by nonexpert endoscopists.

Computer-aided diagnosis of serrated colorectal lesions using non-magnified white-light endoscopic images.

PURPOSE: Computer-aided diagnosis systems for polyp characterization are commercially available but cannot recognize subtypes of sessile lesions. This study aimed to develop a computer-aided diagnosis system to characterize polyps using non-magnified white-light endoscopic images. METHODS: A total of 2249 non-magnified white-light images from 1030 lesions including 534 tubular adenomas, 225 sessile serrated adenoma/polyps, and 271 hyperplastic polyps in the proximal colon were consecutively extracted from an image library and divided into training and testing datasets (4:1), based on the date of colonoscopy. Using ResNet-50 networks, we developed a classifier (1) to differentiate adenomas from serrated lesions, and another classifier (2) to differentiate sessile serrated adenoma/polyps from hyperplastic polyps. Diagnostic performance was assessed using the testing dataset. The computer-aided diagnosis system generated a probability score for each image, and a probability score for each lesion was calculated as the weighted mean with a log10-transformation. Two experts (E1, E2) read the identical testing dataset with a probability score. RESULTS: The area under the curve of classifier (1) for adenomas was equivalent to E1 and superior to E2 (classifier 86%, E1 86%, E2 69%; classifier vs. E2, p < 0.001). In contrast, the area under the curve of classifier (2) for sessile serrated adenoma/polyps was inferior to both experts (classifier 55%, E1 68%, E2 79%; classifier vs. E2, p < 0.001). CONCLUSION: The classifier (1) developed using white-light images alone compares favorably with experts in differentiating adenomas from serrated lesions. However, the classifier (2) to identify sessile serrated adenoma/polyps is inferior to experts.

Risk of Delayed Bleeding after Cold Snare Polypectomy in Patients with Antithrombotic Therapy.

BACKGROUND: Cold snare polypectomy is being increasingly adopted; however, there are few reports of cold snare polypectomy regarding antithrombotic therapy. AIMS: This study aimed to investigate the real-world safety of cold snare polypectomy during antithrombotic therapy. METHODS: We collected data from consecutive patients undergoing cold snare polypectomy in a single hospital between 2013 and 2017. Indications for cold snare polypectomy were any ≤ 10 mm polyp. The primary outcome was delayed bleeding. We compared rates of delayed bleeding between patients with and without antithrombotic therapy and analyzed risk factors for delayed bleeding using binary logistic regression model with firth procedure. RESULTS: In 2152 patients (mean age 67.6 years; male 1411), 4433 colorectal polyps (mean diameter 5.0 mm) underwent cold snare polypectomy. Clipping during the procedure was performed for 5.8%. Delayed bleeding occurred in 0.51% (11/2152) of patients and 0.25% (11/4433) of polyps, but no major delayed bleeding occurred. A total of 244 (11%) patients received antithrombotic therapy. Patients on antithrombotic therapy were older (p < 0.001), more likely male (p < 0.001) and had cold snare polypectomy in the proximal colon (p = 0.011). The rate of delayed bleeding was higher in patients on antithrombotic therapy (1.64% vs. non-antithrombotic therapy 0.37%, p = 0.009). Larger polyp size (> 5 mm), use of clips, and antithrombotic therapy were significant risk factors for delayed bleeding. There was no clear association between specific antithrombotic agents and delayed bleeding. CONCLUSIONS: Delayed bleeding after cold snare polypectomy was rare even in patients with antithrombotic therapy, and no major delayed bleeding occurred.

Validation of the BEST-J score, a prediction model for bleeding after endoscopic submucosal dissection for early gastric cancer: a multicenter retrospective observational study.

BACKGROUND: A new scoring system, the BEST-J score, using ten risk factors to assign cases to different post-endoscopic submucosal dissection (ESD) risk groups for bleeding, has been shown to be accurate for risk stratification. We first aimed to validate the BEST-J score at four hospitals not specialized in performing ESD and then aimed to identify other risk factors for post-ESD bleeding. METHODS: We evaluated the incidence of post-ESD bleeding in 791 cases of early gastric cancer (EGC) between October 2013 and December 2020 as a retrospective, multi-center observational study conducted at four hospitals. Multivariate logistic regression models to examine the effect of independent variables on post-ESD bleeding firstly included ten possible factors raised by the BEST-J score and secondly included statistically significant (p < 0.01) in univariate analysis. The prediction accuracy of the model was evaluated by receiver-operating characteristic analysis and the areas under the curve (AUC). RESULTS: The incidence of post-ESD bleeding was 4.8% (38/791, 95% confidence interval [CI] 3.4-6.5%). On multivariate analysis, the risk factors were P2Y12 receptor antagonist (odds ratio [OR]: 5.870, 95% CI 1.624-21.219), warfarin (8.382, 1.658-42.322), direct oral anticoagulant (DOAC) (8.980, 1.603-50.322), and tumor location in lower third of stomach (2.151, 1.012-4.571), respectively. When we categorized cases into low-risk by BEST-J score, intermediate-risk, high-risk, and very high-risk groups, the bleeding rates were 2.8%, 7.3%, 12.8%, and 19.0%, respectively. The AUC for our cohort was 0.713 (95% CI 0.625-0.802) for the BEST-J score. In the multivariate analysis in our cohort, the risks were age, body mass index, P2Y12 receptor antagonist, warfarin, DOAC, respectively. DISCUSSION: The BEST-J score is equally accurate in risk stratification of patients with EGC for post-ESD bleeding at non-specialized facilities for ESD as in specialized hospitals. BMI and age may be helpful additional risk factors at hospitals not specialized.

[The Evaluation of Neoadjuvant Chemotherapy for Locally Advanced Rectal Cancer].

We evaluated the efficacy of neoadjuvant chemotherapy(NAC)for 38 patients with locally advanced rectal cancer (LARC). We administered mFOLFOX6 in 15, FOLFIRI in 3, CAPOX in 10, IRIS in 1 and FOLFOXIRI in 9 patients. We also used bevacizumab in 31 and panitumumab in 7 patients. There were 27 male and 11 female patients, with a median age of 64 years, and location was RS 2, Ra 9, Rb 21, and P 6. Synchronous distant metastasis was recognized in 13 patients. Nine patients had suffered adverse event of Grade 3, however all patients could complete NAC. Clinical response was CR 3, PR 31, SD 4, response rate was 91.9%, and reduction rate was 43.3(range 18.8-100)%. Clinical response of distant metastasis was CR 3, PR 9 and SD 1. Laparoscopic surgery was performed in 29 patients. Postoperative complications of Grade 2 of Clavien- Dindo classification were recognized in 14 and Grade 3 in 4 patients. Three- and five-year overall survival rate of 25 patients without distant metastasis were 79.6% and 74.9%, respectively; and 13 with distant metastasis were 61.6% and 52.6%, respectively. The efficacy, safety and postoperative outcomes of NAC for LARC are favorable, and we think that NAC will be one of the treatments for LARC.

Polyp detection algorithm can detect small polyps: Ex vivo reading test compared with endoscopists.

BACKGROUND AND STUDY AIMS: Small polyps are occasionally missed during colonoscopy. This study was conducted to validate the diagnostic performance of a polyp-detection algorithm to alert endoscopists to unrecognized lesions. METHODS: A computer-aided detection (CADe) algorithm was developed based on convolutional neural networks using training data from 1991 still colonoscopy images from 283 subjects with adenomatous polyps. The CADe algorithm was evaluated on a validation dataset including 50 short videos with 1-2 polyps (3.5 ± 1.5 mm, range 2-8 mm) and 50 videos without polyps. Two expert colonoscopists and two physicians in training separately read the same videos, blinded to the presence of polyps. The CADe algorithm was also evaluated using eight full videos with polyps and seven full videos without a polyp. RESULTS: The per-video sensitivity of CADe for polyp detection was 88% and the per-frame false-positive rate was 2.8%, with a confidence level of ≥30%. The per-video sensitivity of both experts was 88%, and the sensitivities of the two physicians in training were 84% and 76%. For each reader, the frames with missed polyps appearing on short videos were significantly less than the frames with detected polyps, but no trends were observed regarding polyp size, morphology or color. For full video readings, per-polyp sensitivity was 100% with a per-frame false-positive rate of 1.7%, and per-frame specificity of 98.3%. CONCLUSIONS: The sensitivity of CADe to detect small polyps was almost equivalent to experts and superior to physicians in training. A clinical trial using CADe is warranted.

Prospective randomized trial comparing the pocket-creation method and conventional method of colorectal endoscopic submucosal dissection.

BACKGROUND AND AIMS: Colorectal endoscopic submucosal dissection (ESD) is recognized as a challenging procedure. Previously, we reported that a new ESD strategy using the pocket-creation method (PCM) is useful for colorectal ESD, but no prospective randomized study has evaluated the efficacy of the PCM. The aim of this study was to evaluate the efficacy and safety of PCM for colorectal ESD compared with the conventional method (CM). METHODS: This was a prospective randomized controlled trial at 3 institutions in Japan. Patients with superficial colorectal neoplastic lesions >20 mm predicted to be intramucosal were randomly assigned to undergo ESD using the PCM or CM. Primary outcome was the ESD completion rate defined as completion of colorectal ESD with an en bloc resection using the assigned ESD method without changing to other methods or assisted by other devices. RESULTS: We analyzed 59 patients with 59 colorectal tumors in the PCM group and 55 in the CM group. The ESD completion rate was significantly higher in the PCM group compared with the CM group (93% [55/59] vs 73% [40/55]; P  = .01). En bloc resection rates, R0 resection rates, procedure time, and dissection speed were not significantly different between the 2 groups. The incidence of adverse events was similar in the 2 groups. CONCLUSIONS: Use of the PCM allows the endoscopist to complete the procedure with the intended method more often than the CM with similar clinical outcomes. (Clinical trial registration number: UMIN 000024394.).

Colon Capsule Endoscopy versus CT Colonography in Patients with Large Non-Polypoid Tumours: A Multicentre Prospective Comparative Study (4CN Study).

BACKGROUND/AIMS: Non-polypoid colon lesions compared with polypoid lesions has a high malignant potential. The diagnostic performance of colon capsule endoscopy (CCE) and CT colonography (CTC) for large colorectal non-polypoid tumours, that is, laterally spreading tumours is still unclear. The aim of this study is to evaluate the performance of CCE and CTC for the diagnosis of large non-polypoid tumours. METHODS: Thirty patients referred for endoscopic submucosal dissection of non-polypoid tumours measuring ≥20 mm were enrolled. Patients first underwent CCE, then colonoscopy (without resection) and CTC on the same day. An experienced gastroenterologist in a third hospital evaluated the CCE and recorded the location, size and morphology of all lesions detected, blinded to the colonoscopic findings. An experienced radiologist read the CTC under the same conditions. Colonoscopic findings were defined as the reference. RESULTS: A total of 30 lesions (T1 cancer: 3, Tis cancer: 7, adenoma: 14, sessile serrated adenoma/polyp: 6) in 27 patients were observed for evaluation. The capsule excretion rate within 8 h was 85% (23/27), and all capsules went beyond the target lesions. Non-polypoid tumours tend to be depicted as polypoid on CCE. Per patient sensitivities were 0.89 (24/27) by CCE and 0.70 (19/27) by CTC (p = 0.0253, McNemar), and per lesion sensitivities were 0.87 (26/30) and 0.67 (20/30) respectively (p = 0.0143). Most lesions missed by both modalities were located in the proximal colon. CONCLUSION: Eighty-seven per cent of non-polypoid tumours were detected by CCE, and the sensitivity using CCE was higher than that obtained using CTC (UMIN0000014772).

A novel volume-reduced CT colonography regimen using hypertonic laxative (polyethylene glycol with ascorbic acid): randomized controlled trial.

OBJECTIVES: The aim of this study is to investigate the feasibility of bowel preparation using a hypertonic laxative (polyethylene glycol with ascorbic acid, PEG + Asc) for CT colonography (CTC) and to examine the volume limit of laxative. METHODS: In one institution, patients who met the indications for CTC were enrolled and randomly assigned to CTC with regimen A (800 ml PEG + Asc), B (600 ml PEG + Asc), or C (400 ml PEG + Asc). Sodium diatrizoate was given orally for fecal tagging. On the previous day, patients ate low-residue meals and took the assigned lavage solution after dinner. A reader blinded to the preparation graded residual stool/fluid and fecal tagging quality in six segments of the colorectum. The primary outcome was a proportion of colon segments without stool. One hundred twenty segments in 20 patients with each regimen were needed to show a non-inferiority margin of 15%, assuming 85% of no stool. RESULTS: A total of 360 segments in 60 patients were analyzed. There were 83% of segments with no stool in regimen A, 89% in regimen B, and 88% in regimen C. Using the delta method, the 95% confidence interval of the risk difference (6.7%) between regimens A and B was - 2.2% to 15.6%, and the risk difference (5.0%) between regimens A and C was - 4.1% to 14%, both within the non-inferiority margin. Residual fluid and fecal tagging quality were also within the non-inferiority margin. No adverse events occurred. CONCLUSIONS: A novel CTC regimen using hypertonic laxative demonstrated optimal colon cleansing effectiveness even with the lowest volume of laxative (UMIN000022851). KEY POINTS: • A novel CTC regimen using a hypertonic laxative is feasible. • The lowest volume of laxative provides excellent colon imaging. • However, the lowest volume of laxative did not improve patient acceptance.

Inhibitory effect of lidocaine on colonic spasm during colonoscopy: A multicenter double-blind, randomized controlled trial.

OBJECTIVES: Colonic spasm can interfere with colonoscopy, but antispasmodic agents can cause complications. This study aimed to assess the inhibitory effect of topical lidocaine compared with a placebo control. METHODS: In five tertiary-care hospitals in Japan, 128 patients requiring endoscopic resection of a colorectal lesion were enrolled and randomly and double-blindly allocated to colonoscopy with topical administration of 2% lidocaine solution 20mL (LID, n = 64) or normal saline 20mL (control, n = 64). During colonoscopy, the assigned solution was applied with a spray catheter near the lesion and the area was observed for three minutes. primary endpoint was the inhibitory effect at three time-points (1, 2 and 3 minutes after dispersion), using a three-point scale (excellent, fair, poor). Secondary endpoints were rebound spasm and adverse events. All endpoints were scored in real time. Serum lidocaine levels were measured in 32 patients (LID 16, control 16). RESULTS: There were no significant differences between groups in patient demographics. At all time-points, the proportion of patients with "excellent" scores was greater in LID group than control group, with significant differences observed at 2 minutes (p = 0.02) and 3 minutes (p = 0.02). In LID group, the rate of "excellent" scores increased by 12.5% at 2 minutes and was maintained at 3 minutes. Rebound spasm did not occur in LID group, compared with 15.6% of control group (p = 0.001). There were no adverse events in LID group. All serum lidocaine levels were below detectable levels. CONCLUSIONS: Topical lidocaine is an effective and safe method for suppressing colorectal spasm during colonoscopy (UMIN000024733).

[Curative Transanal Resection after Neoadjuvant Chemotherapy for Lower Rectal Cancer-A Case Report].

A 53-year-old woman was referred to our hospital with melena. Examinations revealed advanced rectal cancer involving the anal canal with invasion of the left-sided levator ani muscle. Neoadjuvant chemotherapy was administered to preserve anal function. A first course of capecitabine and oxaliplatin(CapeOX)plus bevacizumab was administered. CapeOX plus panitumumab was administered from the 2nd to the 8th courses after confirming the absence of RAS mutation. Endoscopy and computed tomography confirmed the disappearance of the tumor after completion of the chemotherapy. A biopsy of the scar tissue revealed no cancer cells. However, diffusion weighted-magnetic resonance imaging(MRI-DWI)revealed a suspected residual tumor. To determine the subsequent treatment, a transanal resection was performed. No carcinoma was identified in the specimen. Thus, additional surgical treatment and adjuvant chemotherapy were not administered. The patient was followed-up over 2.5 years post local resection and showed no recurrence.

[Two Cases of Advanced Colorectal Cancer Achieving Complete Response by FOLFOXIRI plus Bevacizumab-A Case Report].

We report 2 cases of advanced colorectal cancer achieving complete response by FOLFOXIRI plus bevacizumab. Case 1 was a 65-year-old male diagnosed with descending colon cancer with multiple liver metastases. Six courses of FOLFOXIRI plus bevacizumab were administered after laparoscopic-assisted left hemicolectomy. Ten partial hepatectomies and 1 radiofrequency ablation were performed as the liver metastases resolved. A pathological complete response was confirmed. Adjuvant chemotherapy was not administered, and recurrence-free survival was 21 months after hepatectomy. Case 2 was a 77-yearold male diagnosed with rectal cancer invading the pelvic wall and sacral foramen with bilateral lateral lymph node metastasis. Additionally, there was a cancer embolism in the right internal iliac vein. Six courses of FOLFOXIRI plus bevacizumab were administered, and the cancer tissue was absent on subsequent CT and MRI. The cancer was scarred by colonoscopy, and the biopsy showed no malignant cells. Six courses of FOLFIRI plus panitumumab were administered as second-line chemotherapy, and the patient survived without any recurrence after 12 months from initiation of chemotherapy.

Histological Comparison of Cold versus Hot Snare Resections of the Colorectal Mucosa.

BACKGROUND: Delayed postpolypectomy bleeding occurs more frequently after hot resection than after cold resection. OBJECTIVE: To elucidate the underlying mechanism, we performed a histological comparison of tissue after cold and hot snare resections. DESIGN: This is a prospective study, registered in the University Hospital Medical Information Network (UMIN000020104). SETTING: This study was conducted at Aizu Medical Center, Fukushima Medical University, Japan. PATIENTS: Fifteen patients scheduled to undergo resection of colorectal cancer were enrolled. INTERVENTION: On the day before surgery, 2 mucosal resections (hot and cold) of normal mucosa were performed on each patient using the same snare without saline injection. The difference was only the application of electrocautery or not. Resection sites were placed close to the cancer to be included in the surgical specimen. MAIN OUTCOME MEASURES: The primary outcome measure was the depth of destruction. Secondary outcome measures included the width of destruction, depth of the remaining submucosa, and number of vessels remaining at the resection sites. The number and diameter of vessels in undamaged submucosa were also evaluated. RESULTS: All cold resections were limited to the shallow submucosa, whereas 60% of hot resections advanced to the deep submucosa and 20% to the muscularis propria (p < 0.001). There was no significant difference in the width of destruction. The number of remaining large vessels after hot resections trended toward fewer (p = 0.15) with a decreased depth of remaining submucosa (p = 0.007). In the deep submucosa, the vessel diameter was larger (p < 0.001) and the number of large vessels was greater (p = 0.018). LIMITATIONS: Histological assessment was not blinded to the 2 reviewers. Normal mucosa was used instead of adenomatous tissue. CONCLUSIONS: Hot resection caused damage to deeper layers involving more large vessels. This may explain the mechanism for the reduced incidence of hemorrhage after cold snare polypectomy. See Video Abstract at http://links.lww.com/DCR/A631.