Hiroaki Ikematsu

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.

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.

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.

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.

Local Recurrence After Endoscopic Resection for Large Colorectal Neoplasia: A Multicenter Prospective Study in Japan

OBJECTIVES:Conventional endoscopic resection (CER) is a widely accepted treatment for early colorectal neoplasia; however, large colorectal neoplasias remain problematic, as they necessitate piecemeal resection, increasing the risk of local recurrence. Endoscopic submucosal dissection (ESD) can improve the en bloc resection rate. This study aimed to evaluate local recurrence and its associated risk factors after endoscopic resection (ER) for colorectal neoplasias ≥20 mm.METHODS:A multicenter prospective study at 18 medium- and high-volume specialized institutions was conducted in Japan. Follow-up colonoscopy was performed after 12 months in cases of complete resection and after 3–6 months in cases of incomplete resection. Local recurrence was confirmed by endoscopic findings and/or pathological analysis.RESULTS:Follow-up colonoscopy was performed in 1,524 of 1,845 enrolled colorectal neoplasias (mean age, 65 years; 885 men; median tumor size, 32.8 mm). The local recurrence rates were 4.3% (65/1,524), 6.8% (55/808), and 1.4% (10/716) for the entire cohort, for CER, and for ESD, respectively. The relative risks of local recurrence were 0.21 (95% confidence interval, 0.11–0.39) with ESD compared with CER, 0.32 (95% confidence interval, 0.11–0.92) with en bloc ESD compared with en bloc CER, and 0.90 (95% confidence interval, 0.39–2.12) with piecemeal ESD compared with piecemeal CER. Significant factors associated with local recurrence were piecemeal resection, laterally spreading tumors of granular type, tumor size ≥40 mm, no pre-treatment magnification, and ≤10 years of experience in CER, and piecemeal resection only in ESD.CONCLUSIONS:En bloc ESD reduces the local recurrence rate for large colorectal neoplasias. Piecemeal resection is the most important risk factor for local recurrence regardless of the ER method used.

Long-term Outcomes After Resection for Submucosal Invasive Colorectal Cancers

BACKGROUND & AIMS Little is known about the long-term outcomes of patients with submucosal invasive colorectal cancer who undergo endoscopic or surgical resection. We performed a retrospective analysis of long-term outcomes of patients treated for submucosal colon and rectal cancer. METHODS We collected data on 549 patients with submucosal colon cancer and 209 patients with submucosal rectal cancer who underwent endoscopic or surgical resection at 6 institutions over a median follow-up period of 60.5 months. Patients were classified into one of 3 groups: low-risk patients undergoing only endoscopic resection (group A), high-risk patients undergoing only endoscopic resection (group B), and high-risk patients undergoing surgical resection that included lymph node dissection (group C). We assessed recurrence rates, 5-year disease-free survival, and 5-year overall survival. Cox regression analysis was used to compare recurrences. RESULTS The rates of recurrence, disease-free survival, and overall survival in group A for submucosal colon and rectal cancer were 0% versus 6.3% (P < .05), 96% versus 90%, and 96% versus 89%, respectively. For group B, these values were 1.4% versus 16.2% (P < .01), 96% versus 77% (P < .01), and 98% versus 96%, respectively; local recurrence was observed in 5 patients (one with submucosal colon cancer and 4 with submucosal rectal cancer). Tumor location was the only factor that contributed significantly to disease recurrence and death (hazard ratio, 6.73; P = .045). For group C, these values were 1.9% versus 4.5%, 97% versus 95%, and 99% versus 97%, respectively. CONCLUSIONS The risk for local recurrence was significantly higher in high-risk patients with submucosal rectal cancer than in patients with submucosal colon cancer when treated with only endoscopic resection. The addition of surgery is therefore recommended for patients with submucosal rectal cancer with pathologic features indicating a high risk of tumor progression; University Hospital Medical Network Clinical Trials Registry, Number: UMIN 000008635.

CURRENT STATUS IN THE OCCURRENCE OF POSTOPERATIVE BLEEDING, PERFORATION AND RESIDUAL/LOCAL RECURRENCE DURING COLONOSCOPIC TREATMENT IN JAPAN

Bleeding, perforation, and residual/local recurrence are the main complications associated with colonoscopic treatment of colorectal tumor. However, current status regarding the average incidence of these complications in Japan is not available. We conducted a questionnaire survey, prepared by the Colorectal Endoscopic Resection Standardization Implementation Working Group, Japanese Society for Cancer of the Colon and Rectum (JSCCR), to clarify the incidence of postoperative bleeding, perforation, and residual/local recurrence associated with colonoscopic treatment. The total incidence of postoperative bleeding was 1.2% and the incidence was 0.26% with hot biopsy, 1.3% with polypectomy, 1.4% with endoscopic mucosal resection (EMR), and 1.7% with endoscopic submucosal dissection (ESD). The total incidence of perforation was 0.74% (0.01% with the hot biopsy, 0.17% with polypectomy, 0.91% with EMR, and 3.3% with ESD). The total incidence of residual/local recurrence was 0.73% (0.007% with hot biopsy, 0.34% with polypectomy, 1.4% with EMR, and 2.3% with ESD). Colonoscopic examination was used as a surveillance method for detecting residual/local recurrence in all hospitals. The surveillance period differed among the hospitals; however, most of the hospitals reported a surveillance period of 3–6 months with mainly transabdominal ultrasonography and computed tomography in combination with the colonoscopic examination.

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.

Complete closure of a large defect after EMR of a lateral spreading colorectal tumor when using a two-channel colonoscope.

CASE REPORTA 64-year-old man with a positive fecal occult blood testunderwent colonoscopy, at which a protruded Is + IIa(LST-granular type) lesion, 40 3 40 mm in size, withunevensurfacetexturewasdetectedinthelowerrectum.Itwas slightly elevated and had a reddish surface. Chro-moendoscopy with a high-magnification colonoscope(CF240ZI; Olympus Optical Co., Ltd., Tokyo, Japan) andindigo carmine (0.2%) dye demonstrated the surfacecharacter and margin of the lesion (Fig. 1). Staining withcrystal violet (0.05%) revealed a Kudo type IV pit pattern

Narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

Many clinical studies on narrow‐band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low‐grade intramucosal neoplasia, high‐grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.