Usefulness of close observation with non-magnified blue laser imaging for determining cold polypectomy indications

Purpose: To examine the usefulness of non-magnified close observation with blue laser imaging (BLI) using a colonoscope with close observation capability in determining indications for cold polypectomy.

Methods: We conducted an image evaluation study on 100 consecutive colorectal lesions of 10?mm or less which were observed endoscopically without magnification using BLI mode prior to treatment. Two experts and two non-experts reviewed the images using the Japan NBI expert team (JNET) classification and the diagnostic accuracy was analyzed.

Results: The final pathological diagnoses of the 100 lesions were hyperplastic/sessile serrated polyp (HP/SSP), low grade dysplasia (LGD), high grade dysplasia (HGD) and deep submucosal invasive cancer (dSM), respectively, in 12, 79, 9 and 0 lesions. When JNET classification type 1 corresponds to HP/SSP; 2A to LGD; 2B to HGD; and 3 to dSM; the overall diagnostic accuracy was 84.3%. Accuracy was 90.5% for experts and 78.0% for non-experts. High confidence rate was 67.5% for experts and 48.0% for non-experts. In diagnostic accuracy for HGD, the sensitivity, specificity, PPV and NPV were, respectively, 77.8%, 98.9%, 87.5% and 97.8% for experts; and 66.6%, 92.3%, 46.2% and 96.6% for non-experts.

Conclusions: The diagnostic accuracy of unmagnified close observation with BLI using a colonoscope with close observation capability is similar to that reported for magnifying endoscopy and is useful in predicting the histological diagnosis of colorectal polyps of 10?mm or less although the effectiveness may be limited for non-experts. This modality is a potentially useful tool in deciding indications for cold polypectomy.     

Detectability of colorectal neoplastic lesions using a narrow‐band imaging system: A pilot study

Background and Aim: Flat and depressed colorectal neoplastic lesions can be difficult to identify using conventional colonoscopy techniques. Narrow‐band imaging (NBI) provides unique views especially of mucosal vascular network and helps in visualization of neoplasia by improving contrast. The aim of this study was to assess the feasibility of using NBI for colorectal neoplasia screening. Methods: Forty‐seven consecutive patients, who underwent high definition colonoscopy (HDC) screening examinations revealing neoplastic lesions, were enrolled in our prospective study. No biopsies or resections were performed during the initial HDC, but patients in whom lesions were detected underwent further colonoscopies using NBI, with the results of the first examination blinded from the colonoscopist. They then received appropriate treatment. We compared diagnostic detection rates of neoplastic lesions for HDC and NBI procedures using total number of all identified neoplastic lesions as reference standard. Results: Altogether, 153 lesions were detected and analyzed in 43 patients. Mean diagnostic extubation times were not significantly different (P = 0.18), but the total number of lesions detected by NBI was higher (134 vs 116; P = 0.02). Based on macroscopic type, flat lesions were identified more often by NBI (P = 0.04). As for lesion size, only flat lesions < 5 mm were detected more frequently (P = 0.046). Lesions in the right colon were identified more often by NBI (P = 0.02), but NBI missed two flat lesions ≥ 10 mm located there. Conclusions: Narrow band imaging colonoscopy may represent a significant improvement in the detection of flat and diminutive lesions, but a future multi‐center controlled trial should be conducted to fully evaluate efficacy for screening colonoscopies.     

黏膜表面形态特点对大肠息肉病理类型的预判价值

目的在高清非放大结肠镜下观察大肠息肉表面形态特点,与病理组织学诊断进行对照研究,评价息肉黏膜表面形态特点对大肠息肉病理类型的预判能力。方法对142例结直肠息肉患者330枚息肉样病变进行高清结肠镜检查并观察黏膜腺管开口形态,采用窄波带成像技术(narrow band imaging,NBI)观察黏膜表面血管形态(capillary pattern,CP),与息肉病理结果对照判定其敏感性、特异性及准确率。结果高清非放大结肠镜下联合黏膜腺管开口形态及黏膜表面血管形态判定息肉表面形态特点对鉴别肿瘤性与非肿瘤性病变的敏感性为88.2%,特异性为83.6%,阳性预测值为95.5%,阴性预测值为64.4%,准确度为87.3%,阳性相似比为5.4,阴性相似比为0.1。结论高清非放大结肠镜下贴近观察结合NBI显像观察息肉表面形态对于鉴别大肠息肉是否为肿瘤性有重要价值,与病理诊断有较好的符合率,有助于决定进一步治疗及随访方案。     

Time saving with narrow-band imaging for distinguishing between neoplastic and non-neoplastic small colorectal lesions

Background and Aims: For colonoscopic examinations, the narrow‐band imaging (NBI) system is more convenient and timesaving than magnifying chromoendoscopy (MCE). However, the time‐saving aspects of NBI techniques have not been assessed. The present study compared interpretation times between NBI and MCE techniques in distinguishing between neoplastic and non‐neoplastic small colorectal lesions. Methods: Between January and March 2010, 693 consecutive patients who underwent colonoscopy at the National Cancer Center Hospital, Tokyo, Japan, were enrolled. When the first lesion was detected by conventional white‐light observation, the patient was randomly assigned to undergo a sequence of NBI and MCE observations (group A: NBI–MCE, group B: MCE–NBI). The time to diagnosis with each modality (NBI, from changing to NBI until diagnosis; MCE, from the start of indigo carmine solution spraying until diagnosis) was recorded by an independent observer. The sensitivity, specificity, and diagnostic accuracy of the first modality used in each group (NBI or MCE) were assessed by referring to the histopathological data. Results: Seventy‐one patients with 137 lesions were randomized to group A, and 80 patients with 163 lesions to group B. The median interpretation times were 12 s (interquartile range [IQR]: 7–19 s) in group A, and 17 s (IQR: 12–24 s) in group B, the difference being significant (P < 0.001). No significant differences were observed between NBI and MCE in terms of sensitivity, specificity, and diagnostic accuracy. Conclusions: NBI reduces the interpretation times for distinguishing between neoplastic and non‐neoplastic small lesions during colonoscopies, without loss of diagnostic accuracy.     

Meta-analysis for evaluating the accuracy of endoscopy with narrow band imaging in detecting colorectal adenomas

Background and Aim: The aim of this study was to determine whether the use of the narrow band imaging (NBI) system could enhance the accuracy of adenoma detection during an endoscopic examination of the colon and rectum. Methods: MEDLINE, EMBASE, and the Cochrane Library databases were searched along with a hand search of abstracts from relevant conferences up to June 2011. The rates of adenoma and flat adenoma detection, and withdrawal time were analyzed using Review Manager 4.2. Results: A total of 3049 subjects in eight trials were included. Meta‐analysis revealed that there was no statistically significant difference in the rates of adenoma detection between the NBI group and the white light colonoscopy group (pooled relative risk [RR]: 1.09, 95% confidence interval [CI]: 1.00–1.19, P = 0.05). However, after exclusion of high‐definition television modalities, the rate of adenoma detection by NBI was significantly higher than that by white light, particularly for patients with one adenoma (pooled RR 1.36, 95%CI 1.07–1.71, P = 0.02). Endoscopy with the NBI system significantly increased the rate of flat adenoma detection (pooled RR 1.96, 95%CI 1.09–3.52, P = 0.02). However, endoscopy with NBI had longer withdrawal time than that with white light (pooled weighted mean difference: 0.90, 95%CI: 0.38–1.42, P = 0.0006). Conclusions: Endoscopy with NBI seems to improve the detection of flat adenomas, particularly with high‐definition technology, but prolongs the withdrawal time. These results indicate that endoscopy routinely using the NBI system for the surveillance of adenomas may be recommended after the technique is further modified.     

Efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions

Magnifying chromoendoscopy is an exciting new tool and offers detailed analysis of the morphological architecture of mucosal crypt orifices. In this review, we principally show the efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions such as prediction between non‐neoplastic lesions and neoplastic ones, and distinction between endoscopically treatable early invasive cancers and untreatable cancers based on a review of the literature and our experience at two National Cancer Centers in Japan. Overall diagnostic accuracy by conventional view, chromoendoscopy and chromoendoscopy with magnification ranged from 68% to 83%, 82% to 92%, and 80% to 96%, respectively, and diagnostic accuracy of accessing the stage of early colorectal cancer using magnifying colonoscopy was over 85%. Although the reliability depends on the skill in magnifying observation, widespread applications of the magnification technique could influence the indications for biopsy sampling during colonoscopy and the indication for mucosectomy. Moreover, the new detailed images seen with magnifying chromoendoscopy are the beginning of a new period in which new optical developments, such as narrow band imaging system, endocytoscopy system, and laser‐scanning confocal microscopy, will allow a unique look at glandular and cellular structures.     

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.     

Two cases of adenocarcinoma occurring in sporadic fundic gland polyps observed by magnifying endoscopy with narrow band imaging

Gastric fundic gland polyps(FGPs) are common nonadenomatous gastric polyps arising from normal fundic mucosa without Helicobacter pylori(H. pylori) infection. Although systemic FGPs associated with familial adenomatous polyposis(FAP) often have dysplasia, there are few reports of dysplasia occurring in sporadic F G P s, e s p e c i a l l y w h e n d e t e c t e d b y m a g n i f y i n g endoscopy with narrow band imaging(ME-NBI). We experienced two cases of adenocarcinoma occurring in sporadic FGPs, and their ME-NBI findings were very useful for differentiating FGP with cancer from nondysplastic FGP. A 68-year-old man and a 63-year-old woman were referred to our institution for medical checkup. H. pylori was negative in both patients. Endoscopic examination revealed a small reddishpolypoid lesion on the anterior wall of the upper gastric body and several FGPs. ME-NBI showed an irregular microvascular architecture composed of closed loop- or open loop-type vascular components, plus an irregular microsurface structure composed of oval-type surface components which was different from that of FGPs. FAP was denied because of the absence of colon polyps and no familial history of FAP. Pathological diagnosis was adenocarcinoma occurring in sporadic FGP.     

放大内镜窄带成像联合高频腔内超声微探头在大肠广基型/侧方发育型病变微创诊疗中的应用价值

[目的]探讨联合应用放大内镜窄带成像技术(magnifying endoscopy with narrow-band imaging,MENBI)及高频超声微探头(high-frequency mini-probe sonography,HFMPS))对大肠广基型/侧方发育型病变进行术前评估及微创诊疗中的应用价值。[方法]对行结肠镜检查发现大肠广基型/侧方发育型病变且符合入选标准的73例患者,联合应用ME-NBI及HFMPS进行术前评估,根据Sano微血管形态分型及超声内镜对病变浸润深度的判断,将病变浸润深度分为黏膜内或黏膜下层上1/3(m/sm1)和黏膜下层中1/3及以上(sm2),并对照术后病理对其判断准确性做出判断。[结果]73例患者中腺瘤54例,大肠癌19例(8例m/sm1癌、11例sm2)。ME-NBI及HFMPS对70例患者做出了准确的判断,判断的准确度95.89%、灵敏度90.91%、特异度96.77%、阳性预测值83.33%、阴性预测值98.36%。[结论]ME-NBI联合HFMPS对于大肠广基型/侧方发育型病变的术前评估有着良好的应用价值,有助于选择合适的治疗方案,避免不恰当的治疗。     

Randomized,back-to-back trial of a new generation NBI with a high-definition white light (HQ290) for detecting colorectal polyps

Abstract

Background: The benefits of narrow band imaging (NBI) for improving the detection rate of colorectal polyps remain unclear. New generation NBI using the 290 system (290-NBI) provides an at least two-fold brighter image than that of the previous version. We aimed to compare polyp miss rates between 290-NBI colonoscopy and high-definition white light endoscopy (HDWL).

Methods: In total, 117 patients were randomized to undergo either 290-NBI or HDWL from June 2015 to February 2017. In the HDWL group, we performed HDWL as an initial inspection, followed by a second inspection with NBI. In the 290-NBI group, NBI was performed as the initial inspection, followed by a second inspection with HDWL. We compared polyp and adenoma detection rates and polyp miss rates (PMR) between the two groups and analyzed the factors associated with the PMR.

Results: In total, 127 polyps were detected in the 117 patients. No differences in adenoma or polyp detection rates were observed between the two groups. The PMR for 290-NBI was 20.6% and that for HDWL was 33.9% (p?=?.068). However, the non-adenomatous PMR for 290-NBI was significantly lower than that of HDWL (11.5% vs. 52.2%, p?=?.002). Furthermore, the miss rates of polyps on the left side of the colon, flat-type polyps, and non-adenomatous polyps were significantly lower in the 290-NBI than HDWL.

Conclusions: New generation NBI may reduce PMR, especially of flat-type and non-adenomatous polyps and those on the left side of the colon. (UMIN000025505)     

Diagnostic ability of blue laser imaging combined with magnifying endoscopy for early esophageal cancer

BackgroundBlue laser imaging (BLI) is a new image-enhanced endoscopy technique that utilizes a laser light source developed for narrow-band light observation.AimsTo evaluate the value of BLI combined with magnifying endoscopy (M-BLI) for the diagnosis of early esophageal cancers (EECs).MethodsThis single-center prospective study analyzed 149 patients with focal esophageal lesions detected with white light endoscopy (WLE) at Renmin Hospital of Wuhan University between April 2015 and June 2017. In this study, patients were examined sequentially with narrow-band imaging combined with magnifying endoscopy (M-NBI), M-BLI and 1.25% Lugol’s iodine chromoendoscopy. The concordance between endoscopic diagnosis and pathological diagnosis was evaluated using the agreement (kappa) test. The paired chi-square test was used to compare the concordance of M-NBI, M-BLI and Lugol’s iodine chromoendoscopy.ResultsThis study analyzed 153 lesions (four patients had two lesions each). The sensitivity, specificity, accuracy, concordance rates and kappa value of M-BLI were 95.2%, 91.9%, 85.7%, 92.8% and 0.891, respectively; those of M-NBI were 95.2%, 92.8%, 87.5%, 93.5% and 0.906; and those of Lugol’s iodine chromoendoscopy were 95.2%, 94.6%, 91.3%, 94.8% and 0.936.ConclusionM-BLI has a diagnostic profile similar to that of M-NBI and could improve the accuracy of EEC diagnosis.