Toshio Uraoka

A prospective, multicenter study of 1111 colorectal endoscopic submucosal dissections (with video)

BACKGROUND Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment for early gastric cancer, although it is not widely used in the colorectum because of technical difficulty. OBJECTIVE To examine the current status of colorectal ESDs at specialized endoscopic treatment centers. DESIGN AND SETTING Multicenter cohort study using a prospectively completed database at 10 specialized institutions. PATIENTS AND INTERVENTIONS From June 1998 to February 2008, 1111 colorectal tumors in 1090 patients were treated by ESD. MAIN OUTCOME MEASUREMENTS Tumor size, macroscopic type, histology, procedure time, en bloc and curative resection rates and complications. RESULTS Included in the 1111 tumors were 356 tubular adenomas, 519 intramucosal cancers, 112 superficial submucosal (SM) cancers, 101 SM deep cancers, 18 carcinoid tumors, 1 mucosa-associated lymphoid tissue lymphoma, and 4 serrated lesions. Macroscopic types included 956 laterally spreading tumors, 30 depressed, 62 protruded, 44 recurrent, and 19 SM tumors. The en bloc and curative resection rates were 88% and 89%, respectively. The mean procedure time ± standard deviation was 116 ± 88 minutes with a mean tumor size of 35 ± 18 mm. Perforations occurred in 54 cases (4.9%) with 4 cases of delayed perforation (0.4%) and 17 cases of postoperative bleeding (1.5%). Two immediate perforations with ineffective endoscopic clipping and 3 delayed perforations required emergency surgery. Tumor size of 50 mm or larger was an independent risk factor for complications, whereas a large number of ESDs performed at an institution decreased the risk of complications. LIMITATIONS No long-term outcome data. CONCLUSIONS ESD performed by experienced endoscopists is an effective alternative treatment to surgery, providing high en bloc and curative resection rates for large superficial colorectal tumors.

Endoscopic indications for endoscopic mucosal resection of laterally spreading tumours in the colorectum

Background: Laterally spreading tumours (LSTs) in the colorectum are usually removed by endoscopic mucosal resection (EMR) even when large in size. LSTs with deeper submucosal (sm) invasion, however, should not be treated by EMR because of the higher risk of lymph node metastasis. Aims: To determine which endoscopic criteria, including high magnification pit pattern analysis, are associated with sm invasion in LSTs and clarify indications for EMR. Methods: Eight endoscopic criteria from 511 colorectal LSTs (granular type (LST-G type); non-granular type (LST-NG type)) were evaluated retrospectively for association with sm invasion, and compared with histopathological findings. Results: LST-NG type had a significantly higher frequency of sm invasion than LST-G type (14% v 7%; p<0.01). Presence of a large nodule in LST-G type was associated with higher sm invasion while pit pattern (invasive pattern), sclerous wall change, and larger tumour size were significantly associated with higher sm invasion in LST-NG type. In 19 LST-G type with sm invasion, sm penetration determined histopathologically occurred under the largest nodules (84%; 16/19) and depressed areas (16%; 3/19). Deepest sm penetration in 32 LST-NG type was either under depressed areas (72%; 23/32) or lymph follicular or multifocal sm invasion (28%; 1/32 and 8/32, respectively). Conclusions: When considering the most suitable therapeutic strategy for LST-G type, we recommend endoscopic piecemeal resection with the area including the large nodule resected first. In contrast, LST-NG type should be removed en bloc because of the higher potential for malignancy and greater difficulty in diagnosing sm depth and extent of invasion compared with LST-G type.

Efficacy of the Invasive/Non-invasive Pattern by Magnifying Chromoendoscopy to Estimate the Depth of Invasion of Early Colorectal Neoplasms

OBJECTIVE: During colonoscopy, estimation of the depth of invasion in early colorectal lesions is crucial for an adequate therapeutic management and for such task, magnifying chromoendoscopy (MCE) has been proposed as the best in vivo method. However, validation in large-scale studies is lacking. The aim of this prospective study was to clarify the effectiveness of MCE in the diagnosis of the depth of invasion of early colorectal neoplasms in a large series.METHODS: A total of 4,215 neoplastic lesions were evaluated using MCE from October 1998 to September 2005 at the National Cancer Center Hospital, Tokyo, Japan. Lesions were prospectively classified according to the clinical classification of the pit pattern: invasive pattern or non-invasive pattern. All lesions were histopathologically evaluated.RESULTS: There were 3,371 adenomas, 612 intramucosal cancers (m-ca), 232 submucosal cancers (sm-ca): 52 sm superficial (sm1) and 180 sm deep cancers (sm 2–3). Among lesions diagnosed as invasive pattern, 154 out of 178 (86.5%) were sm2–3, while among lesions diagnosed as non-invasive pattern, 4,011 out of 4,037 (99.4%) were adenomas, m-ca, or sm1. Sensitivity, specificity and diagnostic accuracy of the invasive pattern to differentiate m-ca or sm1 (<1000 μm) from sm2–3 (≥1000 μm) were 85.6%, 99.4%, and 98.8%, respectively.CONCLUSION: The determination of invasive or non-invasive pattern by MCE is a highly effective in vivo method to predict the depth of invasion of colorectal neoplasms.

Effectiveness of glycerol as a submucosal injection for EMR

BACKGROUND EMR traditionally is performed by using normal saline solution (NS) as the submucosal fluid cushion. It is thought, however, that NS does not maintain the proper mucosal elevation for EMR of large, flat lesions. We investigated the efficacy of glycerol as the submucosal injection solution. METHODS A total of 110 colorectal laterally spreading tumors (LST) were treated by EMR with glycerol. For comparison, 113 LSTs treated by using NS were studied. The en bloc resection, complete resection, and associated complications rates were evaluated retrospectively. OBSERVATIONS The en bloc resection rate in the glycerol group was 63.6% (70/110) compared with 48.9% (55/113) in the NS group (p < 0.05). The complete resection rate in the glycerol group was 45.5% (50/110) compared with 24.6% (28/113) in the NS group (p < 0.01). The associated complications rate was similar in both groups. CONCLUSIONS It technically was easier and as safe to perform EMR of colorectal LSTs when using glycerol as the submucosal injection solution.

Efficacy of capillary pattern type IIIA/IIIB by magnifying narrow band imaging for estimating depth of invasion of early colorectal neoplasms

BackgroundCapillary patterns (CP) observed by magnifying Narrow Band Imaging (NBI) are useful for differentiating non-adenomatous from adenomatous colorectal polyps. However, there are few studies concerning the effectiveness of magnifying NBI for determining the depth of invasion in early colorectal neoplasms. We aimed to determine whether CP type IIIA/IIIB identified by magnifying NBI is effective for estimating the depth of invasion in early colorectal neoplasms.MethodsA series of 127 consecutive patients with 130 colorectal lesions were evaluated from October 2005 to October 2007 at the National Cancer Center Hospital East, Chiba, Japan. Lesions were classified as CP type IIIA or type IIIB according to the NBI CP classification. Lesions were histopathologically evaluated. Inter and intraobserver variabilities were assessed by three colonoscopists experienced in NBI.ResultsThere were 15 adenomas, 66 intramucosal cancers (pM) and 49 submucosal cancers (pSM): 16 pSM superficial (pSM1) and 33 pSM deep cancers (pSM2-3). Among lesions diagnosed as CP IIIA 86 out of 91 (94.5%) were adenomas, pM-ca, or pSM1; among lesions diagnosed as CP IIIB 28 out of 39 (72%) were pSM2-3. Sensitivity, specificity and diagnostic accuracy of the CP type III for differentiating pM-ca or pSM1 (<1000 μm) from pSM2-3 (≥1000 μm) were 84.8%, 88.7 % and 87.7%, respectively. Interobserver variability: κ = 0.68, 0.67, 0.72. Intraobserver agreement: κ = 0.79, 0.76, 0.75ConclusionIdentification of CP type IIIA/IIIB by magnifying NBI is useful for estimating the depth of invasion of early colorectal neoplasms.

Iatrogenic perforation associated with therapeutic colonoscopy: A multicenter study in Japan

Background and Aim:  Colonic perforation is the serious accidental complication. The aim of this study is to analyze the clinical presentation and management of recent iatrogenic perforations during therapeutic colonoscopy.

Does autofluorescence imaging videoendoscopy system improve the colonoscopic polyp detection rate?--a pilot study.

OBJECTIVES: Colonoscopy is considered the gold standard for the detection of colorectal polyps; however, polyps can be missed with conventional white light (WL) colonoscopy. The aim of this pilot study was to evaluate whether a newly developed autofluorescence imaging (AFI) system can detect more colorectal polyps than WL.METHODS: A modified back-to-back colonoscopy using AFI and WL was conducted for 167 patients in the right-sided colon including cecum, ascending and transverse colon by a single experienced colonoscopist. The patient was randomized to undergo the first colonoscopy with either AFI or WL (group A: AFI-WL, group B: WL-AFI). The time needed for both insertion and examination for withdrawal and all lesions detected in the right-sided colon were recorded.RESULTS: Eighty-three patients were randomized to group A and 84 to group B. The total number of polyps detected by AFI and WL colonoscopy was 100 and 73, respectively. The miss rate for all polyps with AFI (30%) was significantly less than that with WL (49%) (P= 0.01).CONCLUSIONS: AFI detects more polyps in the right-sided colon compared to WL colonoscopy.

A new sinker-assisted endoscopic submucosal dissection for colorectal cancer.

BACKGROUND Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment for early gastric cancer, but it is not widely used to treat the colorectum because of its degree of technical difficulty. Thus, a noninvasive tool that facilitates the direct visualization of the submucosal layer is needed. METHODS Traction-assisted dissection was performed on 4 superficial lesions. The system consisted of a metallic clip attached by a nylon line to a sinker 6 x 4 x 4 mm in size and weighing 1 g. After partially dissecting the submucosa, the clip was attached to the edge of the exfoliated mucosa and the weight of the sinker pulled down the partly resected lesion. OBSERVATIONS In all 4 cases, the sinker allowed direct visualization of the cutting line, and en bloc resection was successfully accomplished. CONCLUSIONS These preliminary results suggest that sinker-assisted ESD is effective for the complete removal of selected superficial early colorectal cancer.

Diagnostic accuracy of narrow-band imaging and pit pattern analysis significantly improved for less-experienced endoscopists after an expanded training program

BACKGROUND Previous reports assessing diagnostic skill using narrow-band imaging (NBI) and pit pattern analysis for colorectal polyps involved only highly experienced endoscopists. OBJECTIVE To evaluate diagnostic skills of less-experienced endoscopists (LEE group) for differentiation of diminutive colorectal polyps by using NBI and pit pattern analysis with and without magnification after an expanded training program. DESIGN Prospective study. PATIENTS This study involved 32 patients with 44 colorectal polyps (27 adenomas and 17 hyperplastic polyps) of < or =5 mm that were identified and analyzed by using conventional colonoscopy as well as non-magnification and magnification NBI and chromoendoscopy followed by endoscopic removal for histopathological analysis. INTERVENTION Before a training course, 220 endoscopic images were distributed in randomized order to residents with no prior endoscopy experience (NEE group) and to the LEE group, who had performed colonoscopies for more than 5 years but had never used NBI. The 220 images were also distributed to highly experienced endoscopists (HEE group) who had routinely used NBI for more than 5 years. The images were distributed to the NEE and LEE groups again after a training class. Magnification NBI and chromoendoscopy images were assessed by using the Sano and Kudo classification systems, respectively. MAIN OUTCOME MEASUREMENTS Diagnostic accuracy and interobserver agreement for each endoscopic modality in each group. RESULTS Diagnostic accuracy was significantly higher, and kappa (kappa) values improved in the LEE group for NBI with high magnification after expanded training. Diagnostic accuracy and kappa values when using high-magnification NBI were highest among endoscopic techniques for the LEE group after such training and the HEE group (accuracy 90% vs 93%; kappa = 0.79 vs 0.85, respectively). LIMITATIONS Study involved only polyps of < or =5 mm. CONCLUSION Using high-magnification NBI increased the differential diagnostic skill of the LEE group after expanded training so that it was equivalent to that of the HEE group.

Endoscopic submucosal resection with a ligation device is an effective and safe treatment for carcinoid tumors in the lower rectum.

Background and Aims:  Various methods for complete endoscopic resection of rectal carcinoid tumors have been reported; however, the number of cases investigated in each study has been limited. The aim of the present study was to clarify the clinical usefulness of a novel technique named endoscopic submucosal resection with a ligation device (ESMR‐L) in a large number of rectal carcinoid tumors.