F. J. C. van den Broek

Endoscopic tri-modal imaging for surveillance in ulcerative colitis: randomised comparison of high-resolution endoscopy and autofluorescence imaging for neoplasia detection; and evaluation of narrow-band imaging for classification of lesions

Background: Endoscopic tri-modal imaging (ETMI) incorporates white light endoscopy (WLE), autofluorescence imaging (AFI) and narrow-band imaging (NBI). Aims: To assess the value of ETMI for the detection and classification of neoplasia in patients with longstanding ulcerative colitis. Design: Randomised comparative trial of tandem colonoscopies. Setting: Academic Medical Centre Amsterdam, Netherlands. Patients and methods: Fifty patients with ulcerative colitis underwent surveillance colonoscopy with ETMI. Each colonic segment was inspected twice, once with AFI and once with WLE, in random order. All detected lesions were inspected by NBI for Kudo pit pattern analysis and additional random biopsies were taken. Main outcome measures: Neoplasia miss-rates of AFI and WLE, and accuracy of the Kudo classification by NBI. Results: Among patients assigned to inspection with AFI first (n = 25), 10 neoplastic lesions were primarily detected. Subsequent WLE detected no additional neoplasia. Among patients examined with WLE first (n = 25), three neoplastic lesions were detected; subsequent inspection with AFI added three neoplastic lesions. Neoplasia miss-rates for AFI and WLE were 0% and 50% (p = 0.036). The Kudo classification by NBI had a sensitivity and specificity of 75% and 81%; however, all neoplasia was coloured purple on AFI (sensitivity 100%). No additional patients with neoplasia were detected by random biopsies. Conclusion: Autofluorescence imaging improves the detection of neoplasia in patients with ulcerative colitis and decreases the yield of random biopsies. Pit pattern analysis by NBI has a moderate accuracy for the prediction of histology, whereas AFI colour appears valuable in excluding the presence of neoplasia. Trial registration number: ISRCTN05272746

Narrow-band imaging versus high-definition endoscopy for the diagnosis of neoplasia in ulcerative colitis.

BACKGROUND AND STUDY AIMS Controversy exists about which colonoscopic technique is most sensitive for the diagnosis of neoplasia in patients with ulcerative colitis. We compared new-generation narrow-band imaging (NBI) to high-definition endoscopy (HDE) for the detection of neoplasia and evaluated NBI for the differentiation of neoplastic from non-neoplastic mucosa. PATIENTS AND METHODS Randomized crossover trial in which patients with ulcerative colitis underwent both NBI and HDE colonoscopy in random order with at least 3 weeks between the two procedures, which were performed by different endoscopists. Lesions detected during the first examination were left in situ in order to enable detection during the second examination as well. Main outcome measures were (1) neoplasia detection, and (2) diagnostic accuracy of NBI for differentiating neoplastic from non-neoplastic mucosa by using the Kudo classification and vascular pattern intensity (VPI). RESULTS Twenty-five patients were randomized to undergo HDE first and 23 to undergo NBI first. Of 16 neoplastic lesions, 11 (69 %) were detected by HDE and 13 (81 %) by NBI ( P = 0.727). Of 11 patients with neoplasia, 9 (82 %) were diagnosed by HDE and 8 (73 %) by NBI ( P = 1.0). The sensitivity, specificity, and accuracy of the Kudo classification were 76 %, 66 % and 67 %. Corresponding figures for VPI were 80 %, 72 %, and 73 %. CONCLUSION NBI does not improve the detection of neoplasia in patients with ulcerative colitis compared to HDE. In addition, NBI proves unsatisfactory for differentiating neoplastic from non-neoplastic mucosa.

Pilot study of probe-based confocal laser endomicroscopy during colonoscopic surveillance of patients with longstanding ulcerative colitis

BACKGROUND AND AIMS Surveillance of patients with ulcerative colitis consists of taking targeted and random biopsies, which is time-consuming and of doubtful efficiency. The use of probe-based confocal laser endomicroscopy (pCLE) may increase efficiency. This prospective pilot study aimed to evaluate the feasibility and diagnostic accuracy of pCLE in ulcerative colitis surveillance. METHODS In 22 patients with ulcerative colitis, 48 visible lesions and 87 random areas were initially evaluated by real-time narrow-band imaging (NBI) and high-definition endoscopy (HDE). Before taking biopsies, fluorescein-enhanced pCLE was performed. All pCLE videos were scored afterwards by two endoscopists who were blinded to histology and endoscopy. Outcome measures were: (1) the feasibility of pCLE, expressed as pCLE imaging time required, percentage of imaging time with clear pCLE histology, and pCLE video quality as rated by two endoscopists; and (2) the diagnostic accuracy of pCLE. RESULTS The median pCLE imaging time required was 98 seconds for lesions vs. 66 seconds for random areas ( P = 0.002). The median percentages of imaging time with clear pCLE histology were 61 % vs. 81 % respectively ( P < 0.001). The pCLE video quality was rated as good/excellent in 69 %. Feasibility was significantly poorer for sessile and pedunculated mobile lesions. The sensitivity, specificity, and accuracy of blinded pCLE were 65 %, 82 %, and 81 %, whereas these figures were 100 %, 89 %, and 92 % for real-time endoscopic diagnosis with NBI and HDE. CONCLUSION This study demonstrates that pCLE for ulcerative colitis surveillance is feasible with reasonable diagnostic accuracy. Future research should show whether increased experience with pCLE improves its ease of use and whether real-time pCLE diagnosis is associated with greater diagnostic accuracy.

Systematic review of endoscopic mucosal resection versus transanal endoscopic microsurgery for large rectal adenomas.

BACKGROUND AND STUDY AIMS Large ( > 2 cm) rectal adenomas are currently treated by either transanal endoscopic microsurgery (TEM) or piecemeal endoscopic mucosal resection (EMR). The potential lower morbidity of EMR may become irrelevant if EMR is less effective. The aim of this study was to compare the safety and effectiveness of EMR and TEM for large rectal adenomas. PATIENTS AND METHODS A systematic review of the literature published between January 1980 and January 2009 was conducted. Pooled estimates of the proportion of patients with recurrence or complications in EMR and TEM studies were compared using random effects meta-regression analysis. Early (after single intervention) and late (excluding re-treatment of residual adenoma detected within 3 months) recurrence rates were calculated. RESULTS A total of 20 EMR studies and 48 TEM studies were included. No studies directly compared EMR with TEM. Mean polyp size was 31 mm (range 2 - 86 mm) for EMR vs. 37 mm (range 3 - 182 mm) for TEM (P = 0.02). Early recurrence rates were 11.2 % (95 % confidence interval [CI] 6.0 - 19.9) for EMR vs. 5.4 % (95 %CI 4.0 - 7.3) for TEM (P = 0.04). Late recurrence rates were 1.5 % (95 %CI 0.6 - 3.9) for EMR vs. 3.0 % (95 %CI 1.3 - 6.9) for TEM (P = 0.29). Postoperative complication rates were 3.8 % (95 %CI 2.8 - 5.3) for EMR vs. 13.0 % (95 %CI 9.8 - 17.0) for TEM (P < 0.001). CONCLUSIONS After single intervention, EMR for large rectal adenomas appears to be less effective but safer than TEM. When outcome data for re-treatment of residual adenoma within 3  months are included, EMR and TEM seem equally effective. Nevertheless, the added morbidity of additional EMRs could not be accounted for in this analysis. A prospective randomized trial seems imperative before making recommendations concerning the treatment of large rectal adenomas.

Endoscopic mucosal resection vs transanal endoscopic microsurgery for the treatment of large rectal adenomas

Aim  Large (> 2 cm) rectal adenomas are currently treated by transanal endoscopic microsurgery (TEM) or piecemeal endoscopic mucosal resection (EMR). The potential lower morbidity of EMR becomes irrelevant if it is less effective. We aimed to compare the safety and effectiveness of EMR and TEM for large rectal adenomas.

Feasibility and Accuracy of Confocal Endomicroscopy in Comparison With Narrow-Band Imaging and Chromoendoscopy for the Differentiation of Colorectal Lesions

OBJECTIVES:Several advanced imaging techniques have been developed to improve differentiation of colorectal lesions. These techniques need to be assessed for both feasibility and accuracy in order to prove their value in daily clinical practice. The current study assessed the feasibility of probe-based confocal laser endomicroscopy (pCLE) in acquiring videos of sufficient quality. Furthermore, the accuracy of pCLE for the differentiation of colorectal lesions was assessed and compared with narrow-band imaging (NBI) and chromoendoscopy (CE).METHODS:Consecutive patients scheduled for surveillance colonoscopy at our centre were included. All procedures were performed by two expert colonoscopists, who previously participated in studies evaluating pCLE, NBI, and CE. All detected lesions during colonoscopy were differentiated real-time with NBI and CE for Kudo pit pattern. Lesions were also assessed real-time for vascular pattern intensity (VPI) during NBI. Subsequently, pCLE videos of each lesion were acquired and biopsies were taken for histopathology. All pCLE videos were assessed post-hoc for the percentage of time demonstrating sufficient image quality (i.e., depicting at least one crypt or vessel). Finally, pCLE videos were assessed post-hoc for diagnostic accuracy by two experts.RESULTS:A total of 154 lesions detected in 64 patients were included. Accuracy of Kudo pit pattern with NBI for predicting neoplasia (88.7%) was significantly better than accuracy of VPI (77.5%, P=0.05) but not significantly different from CE (89.3%, P=0.125). During pCLE, no histology was shown at all on the video in 19 lesions (12%). The mean time to acquire a pCLE video of the remaining 135 lesions was 50 seconds (s.d. 47) per lesion. The median percentage demonstrating sufficient quality per video was 40.5% (interquartile range 21.2–67.0). Accuracy of pCLE for both observers (66.7 and 71.9%) was significantly lower than accuracy of CE (P<0.001) and NBI (P<0.001).CONCLUSIONS:Video acquisition with pCLE could not be achieved in a small number of lesions. The majority of pCLE videos demonstrated insufficient quality in more than half of the time recorded. Moreover, post-hoc accuracy of pCLE was significantly lower in comparison with real-time accuracy of CE and NBI. Future research should assess whether further increase in experience could improve pCLE video acquisition and determine the real-time accuracy of pCLE for differentiating colorectal lesions.

Interobserver agreement and accuracy among international experts with probe-based confocal laser endomicroscopy in predicting colorectal neoplasia

BACKGROUND AND STUDY AIMS A recently developed probe-based, confocal laser endomicroscopy (pCLE) system provides images of surface colonic epithelium in vivo during any endoscopy. Our objective was to assess interobserver agreement, sensitivity, specificity, and overall accuracy in the diagnosis of neoplasia using pCLE. PATIENTS AND METHODS 53 patients undergoing surveillance and screening colonoscopies were enrolled. A total of 75 lesions, were detected and all were inspected by pCLE prior to sampling or polypectomy. Intravenous fluorescein was used to optimize tissue contrast. Three pCLE users, blinded to histopathologic and endoscopic findings, reviewed the set of video sequences for crypt architecture, vessel architecture, and colorectal neoplasia diagnosis. Histopathologic diagnosis from the corresponding biopsies was the reference gold standard. RESULTS Of the 75 colorectal lesions, 50 were neoplastic and 25 non-neoplastic. Interobserver agreement was moderate to good for the classification of neoplasia (kappa 0.55, 78 % pairwise agreement), and moderate for vessel architecture (kappa 0.41, 67 % pairwise agreement) and crypt architecture (kappa 0.49, 69 % pairwise agreement). In distinguishing between neoplastic and non-neoplastic lesions, sensitivity, specificity, and accuracy were 76 %, 72 % and 75 %, respectively. When videos of good or excellent quality only were considered, interobserver agreement for classification of neoplasia was higher (kappa 0.83, 92 % pairwise agreement), as were sensitivity (88 %), specificity (89 %), and accuracy (88 %). CONCLUSION An international collaboration group had moderate to good interobserver agreement using a pCLE system to predict neoplasia, which is acceptable for this study.

Review article: new developments in colonic imaging

Background  Colonoscopic detection and removal of neoplasia from the colorectum prevent the development of colorectal cancer. Sporadic adenomas and neoplasia associated with ulcerative colitis are frequently missed during colonoscopy, as a result of which, interval cancers might develop.

The prevalence of dysplasia in the ileoanal pouch following restorative proctocolectomy for ulcerative colitis with associated dysplasia.

Aim  A recent systematic review indicated that dysplasia present before restorative proctocolectomy is a predictor of subsequent dysplasia in the pouch. This prospective study was carried out to assess the prevalence of dysplasia in the ileal pouch in patients having RPC for ulcerative colitis with co‐existing dysplasia in the operation specimen.

Endoscopic mucosal resection of large rectal adenomas in the era of centralization: Results of a multicenter collaboration

Background and objective Endoscopic mucosal resection (EMR) of large rectal adenomas is largely being centralized. We assessed the safety and effectiveness of EMR in the rectum in a collaboration of 15 Dutch hospitals. Methods Prospective, observational study of patients with rectal adenomas >3 cm, resected by piecemeal EMR. Endoscopic treatment of adenoma remnants at 3 months was considered part of the intervention strategy. Outcomes included recurrence after 6, 12 and 24 months and morbidity. Results Sixty-four patients (50% male, age 69 ± 11, 96% ASA 1/2) presented with 65 adenomas (diameter 46 ± 17 mm, distance ab ano 4.5 cm (IQR 1–8), 6% recurrent lesion). Sixty-two procedures (97%) were technically successful. Histopathology revealed invasive carcinoma in three patients (5%), who were excluded from effectiveness analyses. At 3 months’ follow-up, 10 patients showed adenoma remnants. Recurrence was diagnosed in 16 patients during follow-up (recurrence rate 25%). Fifteen of 64 patients (23%) experienced 17 postprocedural complications. Conclusion In a multicenter collaboration, EMR was feasible in 97% of patients. Recurrence and postprocedural morbidity rates were 25% and 23%. Our results demonstrate the outcomes of EMR in the absence of tertiary referral centers.