Endocytoscopic microvasculature evaluation is a reliable new diagnostic method for colorectal lesions (with video).

BACKGROUND: We previously reported on the efficacy of endocytoscopic classification (EC-C). However, the correlation of the endocytoscopic vascular (EC-V) pattern with diagnoses was unclear. OBJECTIVE: To assess the diagnostic accuracy of the EC-V pattern for colorectal lesions. DESIGN: Retrospective. SETTING: A university hospital. PATIENTS: Patients who underwent endocytoscopy between January 2010 and March 2013. INTERVENTION: We evaluated 198 consecutive lesions according to the EC-V pattern (EC-V1, obscure surface microvessels; EC-V2, clearly observed surface microvessels of a uniform caliber and arrangement; and EC-V3, dilated surface microvessels of a nonhomogeneous caliber or arrangement). MAIN OUTCOME MEASUREMENTS: The diagnostic accuracy for predicting hyperplastic polyps and invasive cancer were compared between the EC-V pattern and other modalities (narrow-band imaging, pit pattern, and EC-C). RESULTS: The sensitivity, specificity, and accuracy of the EC-V1 pattern for diagnosing hyperplastic polyps were 95.5%, 99.4%, and 99.0%, respectively. The sensitivity, specificity, and accuracy of the EC-V3 pattern for diagnosing invasive cancer were 74.6%, 97.2%, and 88.6%, respectively. The diagnostic accuracy of the EC-V pattern for predicting hyperplastic polyps was comparable to the other modalities. For predicting invasive cancer, the EC-V pattern was comparable to narrow-band imaging and pit pattern, although EC-C was slightly more accurate (P = .04). In the substudy, the diagnosis time by using the EC-V pattern was shorter than that with the EC-C pattern (P < .001). LIMITATIONS: A single-center, retrospective study. CONCLUSIONS: The EC-V pattern saved more time than the EC-C pattern and had a diagnostic ability comparable to that of other optical biopsy modalities.

Diagnostic performance of endocytoscopy for evaluating the invasion depth of different morphological types of colorectal tumors.

BACKGROUND AND AIM: Endocytoscopy (EC) is a next-generation endoscopic technique that enables diagnostic imaging at 450× magnification. In the present study, we retrospectively evaluated the diagnostic performance of EC and magnifying chromoendoscopy (MCE) for diagnosing the invasion depth of colorectal tumors. METHODS: We investigated 330 lesions with a ≥10-mm tumor diameter that could be diagnosed by both MCE and EC. The lesions were classified according to morphological type as follows: laterally spreading type-granular (LST-G), laterally spreading type-non-granular (LST-NG), protruding, or depressed. After all lesions had been classified by both pit pattern and EC, qualitative and quantitative (invasion depth) diagnoses were made. The diagnostic accuracy was then compared between pit pattern classification and EC classification. RESULTS: Diagnostic accuracy of EC classification was significantly higher for LST-NG lesions (90.5%) than for protruding lesions (80.6%) (P < 0.05). Diagnostic accuracy for LST-NG lesions was significantly higher with EC classification (90.5%) than with pit pattern classification (79.3%) (P < 0.001). Comparison of the diagnostic performance of EC3a findings using EC classification between LST-NG and protruding lesions revealed a sensitivity of 92.9% versus 11.3% (P < 0.001), positive predictive value of 78.0% versus 27.3% (P < 0.001), negative predictive value of 95.5% versus 56.1% (P < 0.001), and diagnostic accuracy of 87.9% versus 51.2% (P < 0.001), respectively. CONCLUSION: EC is a very useful method for evaluating the invasion depth of LST-NG lesions.

Novel computer-aided diagnostic system for colorectal lesions by using endocytoscopy (with videos).

BACKGROUND: Endocytoscopy enables in vivo observation of nuclei at 450× magnification during GI endoscopy, thus allowing precise prediction of lesion pathology. However, because it requires training and experience, it may be beneficial only when performed by expert endoscopists. OBJECTIVE: To develop and evaluate a novel computer-aided diagnosis system for endocytoscopic imaging (EC-CAD) of colorectal lesions. DESIGN: Pilot study. SETTING: University hospital. PATIENTS: One hundred fifty-two patients with small colorectal polyps (≤10 mm) who had undergone endocytoscopy. INTERVENTION: Test sets of white-light endoscopic images and endocytoscopic images from 176 small colorectal polyps (137 neoplastic and 39 non-neoplastic polyps) were assessed by EC-CAD, 2 expert endoscopists, and 2 trainee endoscopists. MAIN OUTCOME MEASUREMENT: Sensitivity, specificity, and accuracy in predicting neoplastic change by EC-CAD comparing expert and trainee endoscopists. RESULTS: EC-CAD had a sensitivity of 92.0% and an accuracy of 89.2%; these were comparable to those achieved by expert endoscopists (92.7% and 92.3%; P = .868 and .256, respectively) and significantly higher than those achieved by trainee endoscopists (81.8% and 80.4%; P < .001 and .002, respectively). EC-CAD achieved a specificity of 79.5%; this did not differ significantly from that achieved by the experts and trainees. EC-CAD also enabled instant diagnosis, taking only 0.3 seconds for each lesion with perfect reproducibility. LIMITATIONS: No sample size calculation. CONCLUSIONS: EC-CAD provides fully automated instant classification of colorectal polyps with excellent sensitivity, accuracy, and objectivity. Thus, it can be a powerful tool for facilitating decision making during routine colonoscopy.

Efficiency of endocytoscopy in differentiating types of serrated polyps.

BACKGROUND: Accurate endoscopic criteria are needed to differentiate serrated polyps, including hyperplastic polyp (HP), sessile serrated adenoma/polyp (SSA/P), and traditional serrated adenoma (TSA), because some are precursors of colorectal cancers. OBJECTIVE: To determine the endocytoscopic features of each type of serrated polyp, especially the shapes of lumens and nuclei. DESIGN: Retrospective study. SETTING: Single, tertiary-care referral center. PATIENTS: Patients who underwent removal of serrated polyps from May 2005 to December 2012. INTERVENTION: Endocytoscopy was performed. Endocytoscopic images were evaluated by assessing the shapes of the lumens and nuclei of the target lesions. MAIN OUTCOME MEASUREMENTS: The significant endocytoscopic features in differentiating among types of serrated polyps. RESULTS: Of the 58 eligible lesions, 27 were classified as HP, 12 as SSA/P, and 19 as TSA. Most HPs (77.8%) had star-like lumens, and most SSA/Ps (83.3%) had oval lumens. The lumens of TSAs were serrated (31.6%) or villous (68.4%), with both shapes seen only in TSAs. Most HPs (92.6%) and SSA/Ps (75.0%) had small, round nuclei, and all TSAs had fusiform nuclei. Features significantly differentiating TSAs from HPs and SSA/Ps were the presence of fusiform nuclei (P < .001) and villous (P < .001) and serrated (P = .002) lumens. The presence of oval lumens was significantly characteristic of SSA/Ps (P < .001), and the presence of star-like lumens was significantly characteristic of HPs (P < .001). LIMITATIONS: Retrospective design. Single-center study. CONCLUSION: The shape of lumens and nuclei on endocytoscopy can efficiently differentiate among the different types of serrated polyps. ( CLINICAL TRIAL REGISTRATION NUMBER: UMIN Clinical Trials Registry UMIN000007850.).

Double staining with crystal violet and methylene blue is appropriate for colonic endocytoscopy: an in vivo prospective pilot study.

BACKGROUND AND AIM: Endocytoscopy (EC) at ultra-high magnification enables in vivo visualization of cellular atypia of gastrointestinal mucosae. Clear images are essential for precise diagnosis by EC. The aim of the present study was to evaluate the optimal staining method for EC in the colon. METHODS: Thirty prospectively enrolled patients were allocated 1:1:1 to three distinct staining methods: 0.05% crystal violet (CV) alone, 1% methylene blue (MB) alone, or CV+MB (CM double). Normal rectal mucosae were stained with each dye and videos of EC images were recorded. Visibility of nuclei and gland formation after staining were evaluated as 'recognizable' or 'not recognizable'. Time for each parameter to become 'recognizable' was measured, and the average times for the three staining regimens were compared. RESULTS: MB alone and CM double staining resulted in 'recognizable' (102 ± 27 vs 89 ± 22 s, P=0.263) nuclei within comparable periods of time, whereas CV alone was unable to identify nuclei. Gland formation became 'recognizable' sooner after CM double staining than after MB alone (61 ± 16 vs 108 ± 24 s, P<0.001). CONCLUSIONS: Double staining with CV and MB, which rapidly provided recognizable images of both nuclei and gland formation, is an appropriate staining regimen for colonic EC.

Endocytoscopy can provide additional diagnostic ability to magnifying chromoendoscopy for colorectal neoplasms.

BACKGROUND AND AIM: Pit pattern (PIT) diagnosis with magnifying chromoendoscopy is effective diagnostic method for predicting a massively invasive submucosal colorectal cancer (SMm) which has possibility of metastasis, whereas endocytoscopy (EC) is recently reported to provide excellent diagnostic ability by enabling in vivo cellular visualization. The aim was to assess the additional diagnostic value of EC to PIT for diagnosing colorectal lesions. METHODS: We conducted a retrospective comparative analysis using a prospectively recorded database in a referral hospital. The subjects were 538 patients who were detected of a colorectal lesion with use of a magnifying colonoscope with EC capability. Each detected lesion was initially diagnosed by PIT findings followed by EC diagnosis by the on-site endoscopist. The diagnostic abilities in predicting neoplastic change and SMm were compared between PIT and PIT plus EC. RESULTS: Overall, 514 lesions from 455 patients were available for analysis. Of them, there were 58 non-neoplastic lesions, 352 adenomas, 15 slightly invasive submucosal cancers, and 89 SMm. The diagnostic abilities of predicting neoplastic change were comparable between PIT and PIT plus EC: sensitivity was 97.8% versus 97.4%, specificity was 91.4% versus 89.7%, and accuracy was 97.1% versus 96.5%. Regarding those of predicting SMm, PIT plus EC showed additional specificity and accuracy to PIT: specificity was 99.1% versus 97.6% (P = 0.041), and accuracy was 96.3% versus 93.8% (P = 0.004). CONCLUSIONS: Though PIT has feasible diagnostic ability for predicting both neoplastic change and SMm, EC provides additional diagnostic value to PIT diagnosis for predicting SMm.