Surveillance colonoscopy in patients with inflammatory bowel disease: comparison of random biopsy vs. targeted biopsy protocols

Role of ultra-high definition endoscopy (endomicroscopy and endocytoscopy) and real-time histologic examination in inflammatory bowel disease: Scoping review

OBJECTIVES

Confocal laser endomicroscopy (CLE) and endocytoscopy (EC) are ultra-high definition (HD) imaging modalities that enable real-time histological assessment. Although existent for nearly two decades, their role in current clinical decision making in inflammatory bowel disease management is not well defined.

METHODS

We searched PubMed using keywords ("confocal" OR "CLE" OR "endocytoscopy") AND ("IBD" OR "inflammatory bowel" OR "Crohn*" OR "Crohn's" OR "colitis ulcerosa" OR "ulcerative colitis") between 2005 and March 2023. We identified 52 studies for detailed review.

RESULTS

Confocal laser endomicroscopy was useful in real-time assessment of histologic inflammation and dysplasia characterization in both ulcerative colitis (UC) and Crohn's disease. Although CLE was associated with higher per-biopsy yield for UC-associated neoplasia (UCAN), the benefit was offset by higher procedure time, frequent equipment failure, and conflicting results on incremental yield over chromoendoscopy. Assessment of barrier dysfunction by CLE did not correlate with disease/endoscopic activity but could predict major adverse outcomes. The implications of residual CLE abnormalities in endoscopic remission remain uncertain. Ex vivo binding of labeled biologics can help in predicting biologic response in UC. EC can discriminate mucosal inflammatory cells by morphology and allows assessment of histologic activity. EC combined with pit pattern was better than pit pattern alone for UCAN. Artificial intelligence-assisted EC in UCAN needs further study.

CONCLUSION

Ultra-HD imaging in inflammatory bowel disease can be useful in assessment of UCAN, barrier dysfunction, predicting histologic remission, and biologic response. Future controlled studies are warranted to define the role of these novel technologies in clinical decision making.

Endoscopic characterization of neoplastic and non-neoplastic lesions in inflammatory bowel disease: systematic review in the era of advanced endoscopic imaging

Background

Current guidelines strongly recommend the use of validated classifications to support optical diagnosis of lesions with advanced endoscopic imaging in the lower gastrointestinal tract. However, the optimal strategy in inflammatory bowel disease (IBD) is still a matter of debate.

Objectives

To analyze the accuracy of endoscopic classifications or single predictors for in vivo lesion characterization during endoscopic surveillance of IBD with advanced endoscopic imaging.

Design

Systematic review.

Data sources and methods

Medline and PubMed were used to extract all studies which focused on lesion characterization of neoplastic and non-neoplastic lesions in IBD. The diagnostic accuracy of endoscopic classifications and single endoscopic predictors for lesion characterization were analyzed according to type of patients, lesions, and technology used. When available, the rates of true and false positives or negatives for neoplasia were pooled and the sensitivity (SE), specificity (SP), positive predictive value, and negative predictive value (NPV) were calculated.

Results

We included 35 studies (2789 patients; 5925 lesions - 1149 neoplastic). Advanced endoscopic imaging included dye-based chromoendoscopy, virtual chromoendoscopy (VCE), magnification and high-definition endoscopy, confocal laser endomicroscopy (CLE), endocytoscopy, and autofluorescence imaging. The Kudo classification of pit patterns was most frequently used, with pooled SE 83%, SP 83%, and NPV 95%. The endoscopic criteria with the highest accuracy, with minimum SE ⩾ 90%, SP ⩾ 80%, and NPV ⩾ 90% were: the Kudo-IBD classification used with VCE (Fuji Intelligent Color Enhancement and i-SCAN); combined irregular surface and vascular patterns used with narrow band imaging; the Mainz classification used with CLE. Multiple clinical and technical factors were found to influence the accuracy of optical diagnosis in IBD.

Conclusion

No single endoscopic factor has yet shown sufficient accuracy for lesion characterization in IBD surveillance. Conventional classifications developed in the non-IBD setting have lower accuracy in IBD. The use of new classifications adapted for IBD (Kudo-IBD), and new technologies based on in vivo microscopic analysis show promise.

New Technologies in Digestive Endoscopy for Ulcerative Colitis Patients

Ulcerative colitis (UC) is a chronic inflammatory bowel disease primarily affecting the colon and rectum. Endoscopy plays a crucial role in the diagnosis and management of UC. Recent advancements in endoscopic technology, including chromoendoscopy, confocal laser endomicroscopy, endocytoscopy and the use of artificial intelligence, have revolutionized the assessment and treatment of UC patients. These innovative techniques enable early detection of dysplasia and cancer, more precise characterization of disease extent and severity and more targeted biopsies, leading to improved diagnosis and disease monitoring. Furthermore, these advancements have significant implications for therapeutic decision making, empowering clinicians to carefully consider a range of treatment options, including pharmacological therapies, endoscopic interventions and surgical approaches. In this review, we provide an overview of the latest endoscopic technologies and their applications for diagnosing and monitoring UC. We also discuss their impact on treatment decision making, highlighting the potential benefits and limitations of each technique.

Innovative Diagnostic Endoscopy in Inflammatory Bowel Diseases: From High-Definition to Molecular Endoscopy

High-definition endoscopy is one essential step in the initial diagnosis of inflammatory bowel disease (IBD) characterizing the extent and severity of inflammation, as well as discriminating ulcerative colitis (UC) from Crohn's disease (CD). Following general recommendations and national guidelines, individual risk stratification should define the appropriate surveillance strategy, biopsy protocol and frequency of endoscopies. Beside high-definition videoendoscopy the application of dyes applied via a spraying catheter is of additional diagnostic value with a higher detection rate of intraepithelial neoplasia (IEN). Virtual chromoendoscopy techniques (NBI, FICE, I-scan, BLI) should not be recommended as a single surveillance strategy in IBD, although newer data suggest a higher comparability to dye-based chromoendoscopy than previously assumed. First results of oral methylene blue formulation are promising for improving the acceptance rate of classical chromoendoscopy. Confocal laser endomicroscopy (CLE) is still an experimental but highly innovative endoscopic procedure with the potential to contribute to the detection of dysplastic lesions. Molecular endoscopy in IBD has taken application of CLE to a higher level and allows topical application of labeled probes, mainly antibodies, against specific target structures expressed in the tissue to predict response or failure to biological therapies. First pre-clinical and in vivo data from label-free multiphoton microscopy (MPM) are now available to characterize mucosal and submucosal inflammation on endoscopy in more detail. These new techniques now have opened the door to individualized and highly specific molecular imaging in IBD in the future and pave the path to personalized medicine approaches. The quality of evidence was stated according to the Oxford Center of evidence-based medicine (March 2009). For this review a Medline search up to January 2021 was performed using the words “inflammatory bowel disease,” “ulcerative colitis,” “crohn's disease,” “chromoendoscopy,” “high-definition endoscopy,” “confocal laser endomicroscopy,” “confocal laser microscopy,” “molecular imaging,” “multiphoton microscopy.”

A 1-Year Cross-sectional Inflammatory Bowel Disease Surveillance Colonoscopy Cohort Comparing High-definition White Light Endoscopy and Chromoendoscopy

BACKGROUND

We sought to compare the dysplasia detection rate of high-definition white light endoscopy (HDWLE) with that of chromoendoscopy in patients with long-standing inflammatory bowel disease (IBD).

METHODS

This is a retrospective observational cohort of patients with IBD who underwent surveillance colonoscopy between October 1, 2016 and September 30, 2017. We assessed the association between dysplasia detection and multiple variables.

RESULTS

A total of 808 unique colonoscopies were performed, of which 150 (18.6%) included chromoendoscopy. Primary sclerosing cholangitis was a comorbid diagnosis in 24.5% of patients. The performing endoscopist was an IBD specialist with 37.1% of patients and had >10 years' experience with 64.9% of patients. Prior dysplasia had been seen in 245 (30.3%) patients: 102 (68.0%) and 143 (22.0%) among patients who had chromoendoscopy and HDWLE, respectively. Dysplasia in polyps was found in 129 procedures (15.1%). Among patients who had chromoendoscopy and HDWLE, polypoid dysplasia was identified in 50 (33.0%) and 79 (12.0%) patients, respectively, P < 0.01. Dysplasia in random biopsies was found in 39 patients (4.8%): 15 (10%) who had chromoendoscopy and 24 (3.6%) who had HDWLE (P < 0.001). On multivariate analysis, patient and disease characteristics significantly associated with an increased odds for polypoid dysplasia included older age at diagnosis (odds ratio [OR] = 1.3 per 10 years; 95% confidence interval [CI], 1.07-1.60), having an IBD physician endoscopist (OR = 1.6; 95% CI, 1.01-2.67), having an endoscopist with less than 10 years' experience (OR = 1.8; 95% CI (1.16-2.89), and prior random dysplasia (OR = 4.2; 95% CI (1.93-9.17). Concomitant primary sclerosing cholangitis was significantly associated with random dysplasia (OR = 2.3; 95% CI, 1.02-5.07). After multivariate analysis adjusting for these variables, chromoendoscopy was no more likely to identify dysplasia than was HDWLE.

CONCLUSIONS

Chromoendoscopy and HDWLE had a similar diagnostic yield for dysplasia detection in patients with chronic IBD-colitis after adjusting for multiple known risk factors.

Yield of Random Biopsies During Colonoscopies in Inflammatory Bowel Disease Patients Undergoing Dysplasia Surveillance

BACKGROUND

The development of chromoendoscopy (CE) and high definition endoscopy (HDE) has improved detection of subtle colonic dysplasia in patients with inflammatory bowel diseases (IBDs). The role of random biopsies for dysplasia surveillance is unclear.

METHODS

We reviewed patients with IBD who underwent a CE or HDE colonoscopy and had colonic dysplasia detected. Detection of dysplasia was classified as either visible or random and graded as low grade dysplasia (LGD), high grade dysplasia (HGD), or indefinite for dysplasia. Multivariable regression adjusted for relevant confounders examined the predictors of dysplasia detectable on random biopsies alone.

RESULTS

The study included 300 patients (203 ulcerative colitis, 97 Crohn's disease with colonic involvement) contributing 442 colonoscopies; the mean disease duration was 24.5 years; 7.2% had primary sclerosing cholangitis (PSC). Three hundred sixty-two colonoscopies (82%) had only visible dysplasia, 52 (12%) had only random dysplasia, and 28 (6%) had both visible and random dysplasia. Longer disease duration (odds ratio, 1.04; 95% CI, 1.01-1.07), active inflammation (odds ratio, 2.89; 95% CI, 1.26-6.67), and concomitant PSC (odds ratio, 3.66; 95% CI, 1.21-11.08) were associated with detecting dysplasia on random biopsies compared with visible lesions. Patients with random dysplasia (21%) or both random and visible dysplasia (21%) were more likely to undergo surgical resection compared with those with only visible dysplasia (5%; P < 0.001) and have subsequent development of colorectal cancer (15%, 7%, 1%, respectively; P < 0.0001).

CONCLUSION

Nearly one fifth of dysplasia detected in patients with IBD was found on random biopsies. Patients with high risk characteristics may benefit from continuing the practice of random biopsies during surveillance examinations.

Chromoendoscopy: role in modern endoscopic imaging

Detection of early gastrointestinal tract malignancy can be challenging on white light endoscopy especially as lesions can be subtle and inconspicuous. With the advent of electronic chromoendoscopy technologies, lesions which have already been detected can be quickly and "conveniently" characterised. This review will discuss some of the indications and modern applications of chromoendoscopy in various conditions including Barrett's oesophagus, oesophageal squamous cell carcinoma, early gastric cancer, inflammatory bowel disease and neoplastic colonic lesions. In carefully selected situations, chromoendoscopy could still be a useful adjunct to white light endoscopy in day-to-day clinical practice.

Confocal laser endomicroscopy detects colonic inflammation in patients with irritable bowel syndrome: a prospective study

Background and aims  Irritable bowel syndrome (IBS) is considered to be a functional disease, but recent data indicate measurable organic alterations. We aimed to determine the presence of colorectal mucosa microinflammation in vivo via probe-confocal laser endomicroscopy (pCLE) and histological evaluation in IBS patients. Methods  This was a prospective, controlled, nonrandomized single-blind diagnostic trial performed in a tertiary institution. pCLE images and targeted biopsy of each colon segment obtained during colonoscopies of IBS patients and controls were analyzed for inflammatory changes. Biopsies were classified using the Geboes scale, and the odds ratio and overall diagnostic accuracy were calculated. Results  During the 15-month study period, 37 patients were allocated to each group. The mean age was 53.1 ± 14.3 years; 64.9 % were female. Signs of colonic mucosa inflammation were evident on 65.8 % of pCLE images from IBS patients compared to 23.4 % of images from controls (OR 6.28; 4.14-9.52; P  < 0.001). In total, 20/37 patients had microinflammation via pCLE in ≥ 3 colon segments in the IBS group, compared to 1/37 in the control group. A Geboes score > 0 was attributed to 60.8 % of biopsies from patients in the IBS group compared to 27.5 % of biopsies from the control group. The sensitivity, specificity, positive and negative predictive values, observed and interrater agreement of pCLE-detected inflammatory changes in IBS using histology as gold standard were 76 %, 91 %, 76 %, 91 %, 86.5 %, and 66.8 %, respectively. Conclusions  Patients with IBS have a six-fold higher prevalence of colorectal mucosa microinflammation than healthy controls. pCLE might be a reliable method to detect colorectal mucosa microinflammation in IBS patients.

Surgical Management of Dysplasia and Cancer in Inflammatory Bowel Disease

Patients with inflammatory bowel disease are at an increased risk of cancer secondary to long-standing intestinal inflammation. Surgical options must take into account the significant risk of synchronous disease at other colonic sites. Ileal pouch anal anastomosis is a viable option for patients with ulcerative colitis, but this should be restricted to early cancers that are unlikely to require preoperative or postoperative radiation treatment.

High-Definition Chromoendoscopy Versus High-Definition White Light Colonoscopy for Neoplasia Surveillance in Ulcerative Colitis: A Randomized Controlled Trial

OBJECTIVES

Although chromoendoscopy is currently the recommended mode of surveillance in patients with long-standing ulcerative colitis, it is technically challenging and requires a long procedure time. The aim of this study was to compare the dysplasia detection rate of high-definition white light endoscopy with random biopsy (HDWL-R) vs high-definition chromoendoscopy with targeted biopsy (HDCE-T).

METHODS

This was a multicenter, prospective randomized controlled trial involving 9 tertiary teaching hospitals in South Korea. A total of 210 patients with long-standing ulcerative colitis were randomized to undergo either the HDWL-R group (n = 102) or HDCE-T group (n = 108). The detection rates of colitis-associated dysplasia (CAD) or all colorectal neoplasia from each trial arm were compared.

RESULTS

There was no significant difference in the CAD detection rate between HDCE-T and HDWL-R groups (4/102, 3.9% vs 6/108, 5.6%, P = 0.749). However, HDCE-T showed a trend toward improved colorectal neoplasia detection compared with HDWL-R (21/102, 20.6% vs 13/108, 12.0%, P = 0.093). The median (range) time for colonoscopy withdrawal between the 2 groups was similar (17.6 [7.0-43.3] minutes vs 16.5 [6.3-38.1] minutes; P=0.212; for HDWL-R and HDCE-T, respectively). The total number of biopsies was significantly larger in the HDWL-R group (34 [12-72]) compared with the HDCE-T group (9 [1-20]; P < 0.001).

DISCUSSION

On the basis of our prospective randomized controlled trial, HDCE-T was not superior to HDWL-R for detecting CADs.

Meta-analysis of dye-based chromoendoscopy compared with standard- and high-definition white-light endoscopy in patients with inflammatory bowel disease at increased risk of colon cancer

BACKGROUND

Patients with ulcerative colitis have an increased risk of colorectal cancer. We sought to assess the comparative efficacy of standard white-light endoscopy (SDWLE) or high-definition white-light endoscopy (HDWLE) versus dye-based chromoendoscopy through a meta-analysis and rate the quality of evidence using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system.

METHODS

A systematic review of the literature in PubMed, EMBASE, and Web of Science was performed in April 2018. The primary outcome was the number of patients in whom dysplasia was identified using a per patient analysis in randomized controlled trials (RCT) and analyzed separately for non-RCTs. Analysis was performed using RevMan 5.3 reporting random-effects risk ratios.

RESULTS

Of the 27,904 studies identified, 10 studies were included 6 of which were RCTs (3 SDWLE and 3 HDWLE). Seventeen percent (84/494) of patients were noted to have dysplasia using chromoendoscopy compared with 11% (55/496) with white-light endoscopy (relative risk [RR] 1.50; 95% confidence interval [CI], 1.08-2.10). When analyzed separately, chromoendoscopy (n = 249) was more effective at identifying dysplasia than SDWLE (n = 248) (RR, 2.12; 95% CI, 1.15-3.91), but chromoendoscopy (n = 245) was not more effective compared with HDWLE (n = 248) (RR, 1.36; 95% CI, 0.84-2.18). The quality of evidence was moderate. In non-RCTs, dysplasia was identified in 16% (114/698) of patients with chromoendoscopy compared with 6% (62/1069) with white-light endoscopy (RR, 3.41; 95% CI, 2.13-5.47). Chromoendoscopy (n = 58) was more effective than SDWLE (n = 141) for identification of dysplasia (RR, 3.52; 95% CI, 1.38-8.99), and chromoendoscopy (n = 113) was also more effective than HDWLE (n = 257) (RR, 3.15; 95% CI, 1.62-6.13). The quality of the evidence was very low.

CONCLUSION

Based on this meta-analysis, non-RCTs demonstrate a benefit of chromoendoscopy over SDWLE and HDWLE, whereas RCTs only show a small benefit of chromoendoscopy over SDWLE, but not over HDWLE.

Confocal Laser Endomicroscopy in the Evaluation of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, can be effectively monitored with the use of endoscopy. The additional application of small field imaging technology such as confocal laser endomicroscopy CLE during ongoing endoscopic evaluation has led to real-time visualization of mucosal abnormalities and thus in vivo histology. The endomicroscopy (CLE) can improve IBD endoscopic evaluation by identifying seemingly normal-appearing mucosa, assessing the function of the intestinal barrier of the epithelium and vascular permeability, and by characterizing any mucosal lesions, including dysplastic lesions. CLE used during conventional endoscopy could especially facilitate the evaluation of mucosal healing in IBD. In addition, future developments in molecular imaging in IBD may optimize therapeutic approaches by identifying mucosal targets for therapy and determining the reasons for lack of response to specific therapy or subsequent loss of the response.

Augmented Endoscopy for Surveillance of Colonic Inflammatory Bowel Disease: Systematic Review With Network Meta-analysis

INTRODUCTION

Considering the high risk of dysplasia and cancer in inflammatory bowel disease [IBD], surveillance is advocated. However, international guidelines do not reach a uniform recommendation on the way to perform surveillance. We performed a systematic review with a meta-analysis to assess the best endoscopic surveillance strategy in colonic IBD.

METHODS

The systematic review was performed in PubMed/MEDLINE, EMBASE, SCOPUS, and Cochrane databases to identify studies comparing white light endoscopy [WLE] and augmented endoscopy [AE] in the detection of dysplasia/neoplasia in colonic IBD. A sub-analysis between dye-spray chromoendoscopy [DCE], narrow-band imaging [NBI], I-SCAN, full-spectrum endoscopy [FUSE], and auto-fluorescence imaging [AFI] was also performed. Furthermore, a meta-regression and a network meta-analysis were also performed.

RESULTS

A total of 27 studies [6167 IBD patients with 2024 dysplastic lesions] met the inclusion criteria. There was no publication bias. AE showed a higher likelihood of detecting dysplasia than WLE (19.3% vs 8.5%, odds ratio [OR] = 2.036), with an incremental yield [IY] of 10.8%. DCE [OR = 2.605] and AFI [OR = 3.055] had higher likelihood of detecting dysplasia than WLE; otherwise, I-SCAN [OR = 1.096], NBI [OR = 0.650], and FUSE [OR = 1.118] were not superior to WLE. Dysplasia was found in 1256/7267 targeted biopsies [17.3%] and in 363/110 040 random biopsies [0.33%] [OR = 66.559, IY = 16.9%]. Meta-regression found no variable impacting on the efficacy of AE techniques. Network meta-analysis identified a significant superiority of DCE to WLE in detecting dysplasia [OR 2.12], but no other single technique was found to be superior to all others in dysplasia detection.

CONCLUSIONS

DCE was associated with higher likelihood of discovering dysplastic lesions than WLE. Chromoendoscopy is the best supported endoscopic technique for IBD surveillance.

Endoscopic surveillance strategies for dysplasia in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder with an increased risk of colorectal cancer (CRC). This has led to the implementation of surveillance programmes to minimise this risk. Overall, these proactive programmes in association with better medical therapies have reduced the incidence of CRC in this population. Specific populations remain at increased risk, such as younger age at diagnosis, primary sclerosing cholangitis, colonic strictures and pseudopolyps. The majority of gastrointestinal international societies favour chromoendoscopy with targeted biopsies or random biopsies. The aim of this review is to present the current literature on dysplasia surveillance, the methodology and endoscopic technology available to assess dysplasia in UC.

DALM, rest in peace: a pathologist's perspective on dysplasia in inflammatory bowel disease in the post-DALM era

There are few abbreviations in surgical pathology that are associated with as much immediate recognition, frustration, and confusion as DALM (dysplasia-associated lesion or mass). DALM is used to describe endoscopically visible dysplastic lesions in the surveillance of patients with inflammatory bowel disease. However, the diagnosis of DALM has been complicated by the inconsistent criteria and use of terminology for describing dysplasia in inflammatory bowel disease, and a tendency to relate DALM with the need for colectomy. Fortunately, advancements in both endoscopic visualization and local excision capability have allowed for a more defined management of dysplasia in inflammatory bowel disease. In 2015, the Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus Recommendations (SCENIC) Development Panel, a panel of predominantly expert gastroenterologists and endoscopists in surveillance of inflammatory bowel disease, published a consensus statement. One recommendation was to abandon DALM-related terminology in favor of endoscopic descriptors modified from the Paris endoscopic classification. Recommendations on surveillance and management of dysplastic lesions were also provided. Nevertheless, interval carcinomas and metachronous neoplasia remain persistent issues. This review aims to provide an update on the post-DALM terminology and management recommendations for inflammatory bowel disease-associated dysplasia necessary for a meaningful communication between pathologists and clinicians.

Modern Endoscopic Imaging in Diagnosis and Surveillance of Inflammatory Bowel Disease Patients

Endoscopy remains the most important diagnostic and monitoring modality in the management of inflammatory bowel disease. Advances in imaging have progressively added new tools into the armamentarium of endoscopists with the goal of more accurate, sensitive, and accessible visual diagnoses for the benefit of patients with gastrointestinal diseases. Here, we review the relevant literature regarding commonly used endoscopic techniques (dye-based and digital chromoendoscopy, high-definition endoscopy, capsule endoscopy, and endosonography), as well as advanced and experimental technologies (full-spectrum endoscopy, endocytoscopy, autofluorescence, laser endoscopy, and endomicroscopy, including molecular imaging), applicable to inflammatory bowel diseases and emerging for implementation into everyday practice. Additionally, we discuss future directions and techniques as candidates for a superior inflammation imaging in the diagnosis and prediction of therapeutic response.

Are random biopsies still useful for the detection of neoplasia in patients with IBD undergoing surveillance colonoscopy with chromoendoscopy?

BACKGROUND

Colonoscopy with pan-chromoendoscopy (CE) is superior to standard colonoscopy in detecting neoplasia in patients with IBD. Performing random biopsies in unsuspicious mucosa after CE remains controversial.

METHODS

Consecutive patients with IBD who underwent surveillance colonoscopy using CE were prospectively included. The standardised procedure used CE, performed targeted biopsies or endoscopic resection on suspicious lesions and then quadrant random biopsies every 10 cm. A panel of five expert pathologists reviewed histological slides with dysplasia. Logistic regression model was used to evidence the factors associated with neoplasia in any or in random biopsies.

RESULTS

1000 colonoscopes were performed in 1000 patients (495 UC, 505 Crohn's colitis). In 82 patients, neoplasia was detected from targeted biopsies or removed lesions, and among them dysplasia was detected also by random biopsies in 7 patients. Importantly, in 12 additional patients dysplasia was only detected by random biopsies. Overall, 140 neoplastic sites were found in 94 patients, 112 (80%) from targeted biopsies or removed lesions and 28 (20%) by random biopsies. The yield of neoplasia by random biopsies only was 0.2% per-biopsy (68/31 865), 1.2% per-colonoscopy (12/1000) but 12.8% per-patient with neoplasia (12/94). Dysplasia detected by random biopsies was associated with a personal history of neoplasia, a tubular appearing colon and the presence of primary sclerosing cholangitis (PSC).

CONCLUSIONS

Despite their low yield, random biopsies should be performed in association with CE in patients with IBD with a personal history of neoplasia, concomitant PSC or a tubular colon during colonoscopy.

TRIAL REGISTRATION NUMBER

IRB 001508, Paris 7 University.

An Update on Surveillance in Ulcerative Colitis

PURPOSE OF REVIEW

Patients with long-standing ulcerative colitis have an increased risk for the development of colorectal cancer (CRC). Colitis-related dysplasia appears to confer the greatest risk. Colonoscopic surveillance to detect dysplasia has been advocated by gastrointestinal societies. The aim of surveillance is the reduction of mortality and morbidity of CRC through detection and resection of dysplasia or detecting CRC at an earlier and potentially curable stage. Traditional surveillance has relied on mucosal assessment with targeted biopsy of visible lesions and random biopsy sampling on the premise that dysplasia was not visible at endoscopy. Advances in optical technology permitting increased detection of dysplasia and evidence that most dysplasia is visible has had practice-changing implications.

RECENT FINDINGS

Emerging evidence favours chromoendoscopy (CE) for dysplasia detection and is gaining wider acceptance through recent international (International Consensus Statement on Surveillance and Management of Dysplasia in Inflammatory Bowel Disease (SCENIC)) recommendations and endorsed by many gastrointestinal societies. Adoption of CE as the gold standard of surveillance has been met with by scepticism, from conflicting data, operational barriers and the need to understand the true impact of increasingly higher dysplasia detection on overall CRC mortality. Valid debate notwithstanding, implementation of a risk stratification protocol that includes CE is an effective approach allowing earlier detection of dysplasia and colorectal neoplasia, determination of surveillance intervals with appropriate allocation of resources and limiting morbidity from CRC and colonoscopy itself. Further prospective data should define the true and long-term impact of dysplasia detection with modern techniques.

Detecting dysplasia using white light endoscopy or chromoendoscopy in ulcerative colitis patients without primary sclerosing cholangitis: A systematic review and meta-analysis

BACKGROUND

Endoscopic examinations are a vital diagnostic tool for dysplasia. Establishing the precision of different modes of examination is essential due to the disparate pick-up rates of dysplasia.

OBJECTIVE

The aim of this article was to establish the pick-up rates of dysplastic or cancerous lesions using white light endoscopy (WLE) and random/targeted biopsies, or chromoendoscopy (CE), in patients with ulcerative colitis (UC) without primary sclerosing (PSC) or Crohn's disease (CD).

DATA SOURCES

A systematic review to identify all studies up to November 2017, without language restriction, was conducted from PubMed, the Cochrane Controlled Trials Register (1960-2017), MEDLINE, CINAHL and EMBASE (1981-2017). MeSH and text word terms used included "ulcerative colitis", "dysplasia", "random biopsy", "targeted biopsy", "colonoscopy", "white light", and "chromoendoscopy". Further searches were performed using the bibliographies of these articles.

STUDY SELECTION

All studies reporting on colonoscopy detection rates of dysplasia and cancers in UC without involvement of PSC or CD were included. There was no age restriction to include patients.

DATA EXTRACTION

Outcome data were extracted by 2 authors independently using outcome measures defined a priori. Quality assessment was performed using the Newcastle-Ottawa scales.

DATA SYNTHESIS

Data were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. The pooled overall pick-up rate of dysplastic/cancerous lesions on WLE random biopsies was 5.6% [Event rate 0.06 (0.01, 0.23), df = 4, I2 = 94%]. Using a combined random and targeted approach with WLE the incidence was 5.1% [Event rate 0.05 (0.03, 0.09), df = 4, I2 = 96%]. One study reported on CE and found a 7% pick-up rate for dysplastic lesions.

CONCLUSIONS

Endoscopic examination of UC patients without PSC identifies dysplastic or cancerous lesions in 5-7% of cases. WLE and random biopsies may pick-up a similar number of lesions to targeted biopsies, however the number of biopsies may need to be greater to achieve this equivalence. CE has a slightly higher pick-up rate. Further comparative studies are required to strengthen the body of evidence.

Segmental Resection versus Total Proctocolectomy for Crohn's Colitis: What is the Best Operation in the Setting of Medically Refractory Disease or Dysplasia?

Crohn's disease (CD) may affect any part of the gastrointestinal tract. When isolated to the colon, and patients become medically refractory, there are several surgical options - segmental resection, subtotal colectomy with ileorectal anastomosis, or a total proctocolectomy and end ileostomy. Unfortunately, surgery does not cure CD, and, regardless of the extent of bowel removed, recurrence may be seen in the small bowel. This may lead to need for further immunosuppression or surgery. Therefore, when appropriate, a segmental colectomy or subtotal colectomy may prevent a permanent ostomy required with a total proctocolectomy. In the setting of dysplasia identified on colonoscopy, low quality evidence guides our treatment paradigms. Even though identification of dysplasia has greatly improved with chromoendoscopy, rates of synchronous or metachronous neoplasm remain high. Thus, a total proctocolectomy and end ileostomy, whereas a larger operation, may be best for the patient to remove all at risk tissue. Further research with prospective or randomized control trials is needed to improve our practice guidelines of both scenarios.

Real-life chromoendoscopy for neoplasia detection and characterisation in long-standing IBD

OBJECTIVE

Outside clinical trials, the effectiveness of chromoendoscopy (CE) for long-standing IBD surveillance is controversial. We aimed to assess the effectiveness of CE for neoplasia detection and characterisation, in real-life.

DESIGN

From June 2012 to 2014, patients with IBD were prospectively included in a multicentre cohort study. Each colonic segment was evaluated with white light followed by 0.4% indigo carmine CE. Specific lesions' features were recorded. Optical diagnosis was assessed. Dysplasia detection rate between expert and non-expert endoscopists and learning curve were ascertained.

RESULTS

Ninety-four (15.7%) dysplastic (1 cancer, 5 high-grade dysplasia, 88 low-grade dysplasia) and 503 (84.3%) non-dysplastic lesions were detected in 350 patients (47% female; mean disease duration: 17 years). Colonoscopies were performed with standard definition (41.5%) or high definition (58.5%). Dysplasia miss rate with white light was 40/94 (57.4% incremental yield for CE). CE-incremental detection yield for dysplasia was comparable between standard definition and high definition (51.5% vs 52.3%, p=0.30). Dysplasia detection rate was comparable between expert and non-expert (18.5% vs 13.1%, p=0.20). No significant learning curve was observed (8.2% vs 14.2%, p=0.46). Sensitivity, specificity, and positive and negative predictive values for dysplasia optical diagnosis were 70%, 90%, 58% and 94%, respectively. Endoscopic characteristics predictive of dysplasia were: proximal location, loss of innominate lines, polypoid morphology and Kudo pit pattern III-V.

CONCLUSIONS

CE presents a high diagnostic yield for neoplasia detection, irrespectively of the technology and experience available in any centre. In vivo, CE optical diagnosis is highly accurate for ruling out dysplasia, especially in expert hands. Lesion characteristics can aid the endoscopist for in situ therapeutic decisions.

TRIAL REGISTRATION NUMBER

NCT02543762.

Targeting Mucosal Endothelin-A-Receptor Expression by Fluorescence Endoscopy is Feasible to Detect and Characterize Colitis-Associated Cancer in Mice

BACKGROUND

To facilitate onsite decision-making during endoscopy, both accurate detection and in vivo characterization of preneoplasia are prerequisites. However, no endoscopy technique is available that meets both demands satisfactorily. We evaluated endothelin-receptor A (ETAR)-guided fluorescence endoscopy (FE) in vivo and fluorescence reflectance imaging (FRI) ex vivo for detection and characterization of early dysplastic colitis-associated colonic lesions.

METHODS

Colorectal cancerogenesis was investigated in the inflammatory driven AOM-DSS model and spontaneous adenoma development in ApcMin mice. A Cy5.5-labeled nonpeptidic ETAR-specific imaging probe was injected intravenously to assess tumor development in vivo by white light endoscopy (WLE) and FE. Ex vivo tumors were evaluated by FRI, histological examination, and western blot analysis. In addition, tissue samples from patients with colitis-associated malignant and nonmalignant mucosal alterations were analyzed. Specificity experiments were performed using an unspecific Cy3.5-glycine tracer.

RESULTS

Overall, 62 adenomas were observed. FE was able to detect and quantify ETAR expression targeting the ETAR-specific photoprobe. A significantly higher fluorescent contrast was detected in colonic adenomas compared to adjacent nonmalignant mucosa by FE (64.3 ± 7.9 vs. 56.6. ± 7.0; P < 0.001). These results were confirmed by FRI examination, immunochemistry, and western blot analysis. Additionally, ETAR expression in samples from human patients with colitis-associated cancer was highly elevated compared to nonmalignant alterations. Specificity experiments indicated a high binding-specificity of the applied ETAR photoprobe (1.4 ± 0.3 vs. 2.5 ± 0.7; P < 0.001).

CONCLUSIONS

We introduced ETAR guided FE in mice for successful in vivo detection and characterization of colorectal neoplasia on a molecular level.

Role of Advanced Endoscopic Imaging Techniques in the Management of Inflammatory Bowel Disease

Endoscopy plays a crucial role in the management of inflammatory bowel disease (IBD) in terms of diagnosis, monitoring of mucosal status, and surveillance of colitis-associated neoplasia. Mucosal healing evaluated by endoscopy has been recognized as the target of treatment in the era of powerful biologics therapy. The optimal modality for identifying dysplasia in IBD has yet to be well defined. Increasing progress has recently been made in endoscopic technologies to more accurately assess mucosal inflammation and more effectively detect dysplasia. Here we review the data of advanced endoscopic imaging techniques such as chromoendoscopy, virtual chromoendoscopy, endocytoscopy, and confocal laser endomicroscopy in the management of IBD.

Strategies for detecting colon cancer in patients with inflammatory bowel disease

BACKGROUND

Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer (CRC) compared with the general population. This review assessed the evidence that endoscopic surveillance may prolong life by allowing earlier detection of CRC or its pre-cursor lesion, dysplasia, in patients with inflammatory bowel disease (IBD).

OBJECTIVES

To assess the effectiveness of cancer surveillance programs for diagnosis of IBD-associated colorectal cancer and in reducing the mortality rate from colorectal cancer in patients with IBD.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL and clinical clinicaltrials.gov from inception to 19 September 2016. We also searched conference abstracts and reference lists to identify additional studies.

SELECTION CRITERIA

Potentially relevant articles were reviewed independently and unblinded by two authors to determine eligibility. Randomised controlled trials (RCTs) or observational studies (cohort or case control) assessing any form of endoscopic surveillance aimed at early detection of CRC were considered for inclusion. Studies had to have a no surveillance comparison group to be eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eligible studies were reviewed in duplicate and the results of the primary research trials were independently extracted by two authors. The primary outcome was detection of CRC. Secondary outcomes included death from CRC, time to cancer detection, time to death and adverse events. Deaths from CRC were derived from life tables, survival curves or where possible, by calculating life tables from the data provided. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a P value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present, the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled odds ratio (OR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel. The methodological quality of the included studies was assessed using the Newcastle-Ottawa scale for non-randomised studies The overall quality of the evidence supporting the primary and selected secondary outcomes was assessed using the GRADE criteria.

MAIN RESULTS

No RCTs were identified. Five observational studies (N = 7199) met the inclusion criteria. The studies scored well on the Newcastle-Ottawa scale, but due to the nature of observational studies, a high risk of bias was assigned to all the studies. Three studies were pooled to assess the rate of cancer detected in the surveillance group compared to the non-surveillance group. The studies found a significantly higher rate of cancer detection in the non surveillance group compared to the surveillance group. CRC was detected in 1.83% (53/2895) of patients in the surveillance group compared to 3.17% (135/4256) of patients in the non-surveillance group (OR 0.58, 95% CI 0.42 to 0.80; P = 0.0009). Four studies were pooled to assess the death rate associated with CRC in patients who underwent surveillance compared to patients who did not undergo surveillance. There was a significantly lower death rate associated with CRC in the surveillance group compared to the non-surveillance group. Eight per cent (15/176) of patients in the surveillance group died from CRC compared to 22% (79/354) of patients in the non-surveillance group (OR 0.36, 95% CI 0.19 to 0.69, P=0.002). Data were pooled from two studies to examine the rate of early stage versus late stage colorectal cancer (Duke stages A & B compared to Duke stages C & D) in patients who underwent surveillance compared to patients who do not undergo surveillance. A significantly higher rate of early stage CRC (Duke A & B) was detected in the surveillance group compared to the non-surveillance group. Sixteen per cent (17/110) of patients in the surveillance group had early stage CRC compared to 8% (9/117) of patients in the non-surveillance group (OR 5.40, 95% CI 1.51 to 19.30; P = 0.009). A higher rate of late stage CRC (Duke C & D) was observed in the non-surveillance group compared to the surveillance group. Nine per cent (10/110) of patients in the surveillance group had late stage CRC compared to 16% (19/117) of patients in the non-surveillance group (OR 0.46, 95% CI 0.08 to 2.51; P = 0.37). A GRADE analysis indicated that the quality of the data was very low for all of these outcomes. The included studies did not report on the other pre-specified outcomes including time to cancer detection, time to death and adverse events.

AUTHORS' CONCLUSIONS

The current data suggest that colonoscopic surveillance in IBD may reduce the development of both CRC and the rate of CRC-associated death through early detection, although the quality of the evidence is very low. The detection of earlier stage CRC in the surveillance group may explain some of the survival benefit observed. RCTs assessing the efficacy of endoscopic surveillance in people with IBD are unlikely to be undertaken due to ethical considerations.

Endoscopic Surveillance in Long-standing Colitis

OPINION STATEMENT

There is a relative increase in the risk of colon cancer in patients with inflammatory bowel disease (IBD) affecting the colon, and endoscopic surveillance is advocated to mitigate this risk. The current standard practice is to survey this high-risk patient population using colonoscopy. Chromoendoscopy with targeted biopsies has emerged as the colonoscopy modality recommended by the major societies to optimize dysplasia detection. Studies over the past year support the improved yield from targeted as compared to random biopsies and improved dysplasia detection from chromoendoscopy as compared to white light endoscopy. Ongoing efforts should focus on the implementation of chromoendoscopy as the primary modality for colorectal cancer surveillance in IBD. Our review will describe current status and provide an update on the recent literature on surveillance colonoscopy in patients with IBD.

Confocal endomicroscopy in diagnosis of intestinal chronic graft-versus-host disease

Graft-versus-host disease (GvHD) is a major complication of allogeneic stem cell transplantation. High-resolution in vivo histology of the intestine by confocal endomicroscopy (CEM) detects acute GvHD (aGvHD) with high sensitivity. This pilot study aims to evaluate the diagnostic value of CEM for intestinal chronic GvHD (cGvHD). The study included 20 patients with gastrointestinal symptoms and confirmed cGvHD in other organs as well as 20 patients with clinically suspected acute GvHD for control. Confocal endomicroscopy was performed as gastroscopy followed by sigmoidoscopy after intravenous injection of fluorescein (10%) and topical application of acriflavine (0.05%). Histopathology from H&E-stained biopsy samples throughout the intestinal tract complemented the survey. All histological features of intestinal cGvHD were predominantly mild to moderate. Stroma fibrosis detected by standard histology (16/20 patients) was not seen by CEM. Apoptosis assessed by histology in 12/20 patients was concordant with CEM (8/12 patients). Confocal endomicroscopy revealed esophageal manifestation of cGvHD in 3 patients. For each biopsy site, CEM correlated with intestinal histology (r = 0.64). Classical histology from intestinal biopsy samples taken under CEM monitoring confirmed the final diagnosis of cGvHD. The sensitivity of CEM with 40% in cGvHD was significantly lower compared to 70% in patients with aGvHD. Confocal endomicroscopy detected acute features of cGvHD and contributed to the diagnosis of esophageal cGvHD but failed to display stroma fibrosis in vivo. Although CEM represents a useful noninvasive tool in routine diagnostic of intestinal aGvHD, the method is not sufficient to fully establish the diagnosis of cGvHD within the intestinal tract. Confocal endomicroscopy allowed acquisition of targeted biopsies in patients suspected of having cGvHD.

Advanced endoscopy imaging in inflammatory bowel diseases

BACKGROUND AND AIMS

Rapid assessment of mucosal inflammation is of crucial importance for the initial diagnosis and the assessment of mucosal healing in inflammatory bowel disease (IBD). Moreover, the identification of intraepithelial neoplasias in IBD is of key relevance for clinical management. Here, we systematically analyzed the utility of advanced endoscopic imaging techniques for optimized diagnosis in IBD.

METHODS

PubMed/Medline, Web of Knowledge, and Cochrane library were searched twice for diagnostic studies on advanced endoscopic imaging in IBD. Clinical and technical information was retrieved and subsequently analyzed. Main outcome parameters consisted of the quality of the results, adverse events, and diagnostic yield.

RESULTS

Fifty-six clinical studies with a total of 3296 patients were selected for final analysis. Filter technologies permitted a more detailed analysis of mucosal inflammation in IBD. In spite of substantial heterogeneity across studies, dye-based chromoendoscopy with targeted biopsy sampling yielded higher detection rates of intraepithelial neoplasias in ulcerative colitis as compared with white-light endoscopy with random biopsy sampling. Moreover, endocytoscopy and endomicroscopy allowed subsurface imaging of inflamed or neoplastic mucosa in IBD at subcellular resolution. Finally, endomicroscopy-aided molecular imaging enabled the identification of membrane-bound tumor necrosis factor on mucosal cells as a potential driver of disease activity in Crohn's disease. No relevant adverse events were reported.

CONCLUSIONS

Advanced endoscopic imaging technologies are feasible, safe, and partially effective tools for detailed diagnosis of mucosal inflammation and detection of neoplasias in IBD. Results obtained from these advanced techniques may provide a rational basis for individualized, optimized therapy for IBD patients.

Advanced imaging in colonoscopy: contemporary approach to dysplasia surveillance in inflammatory bowel disease

Inflammatory bowel disease (IBD) (ulcerative colitis (UC) and Crohn's disease (CD)) is a chronic relapsing/remitting condition characterised by intestinal inflammation. One of the main concerns in patients with longstanding ulcerative and Crohn's colitis is development of colonic dysplasia and colorectal cancer (CRC), a risk higher than that of the general population. Colonoscopy surveillance programmes have been developed by major societies worldwide to improve early dysplasia detection and treatment, thus preventing progression to colorectal cancer. Colonoscopy is an imperfect tool as lesions can be missed, an issue even more relevant to colitic patients, where mucosal inspection and lesion recognition may prove challenging. Extensive research has been undertaken on performance improvement in this area while technical advances in optical imaging, such as high-definition, have made their way into modern endoscopy units. Techniques and technologies available to enhance optical diagnosis of dysplasia in inflammatory bowel disease are reviewed in this paper, focusing on those that are realistic, widely available and feasible for everyday practice.

Endomicroscopy and Molecular Tools to Evaluate Inflammatory Bowel Disease

Endoscopy is an essential tool for effective care of patients with inflammatory bowel disease (IBD), including Crohn disease and ulcerative colitis. The newest endoscopic small-field imaging technologies with confocal endomicroscopy have allowed real-time imaging of gastrointestinal mucosal during ongoing endoscopic evaluation and in vivo histology. Thus, endomicroscopy has a potential to further enhance the endoscopic evaluation of IBD. Advances in molecular in vivo imaging in IBD may be used not only to better understand the pathophysiology of IBD but also to guide optimized therapy and thus to allow a personalized, new approach to the IBD management.

Advances in endoscopic imaging in ulcerative colitis

Modern strategies for the treatment of ulcerative colitis require more accurate tools for gastrointestinal imaging to better assess mucosal disease activity and long-term prognostic clinical outcomes. Recent advances in gastrointestinal luminal endoscopy are radically changing the role of endoscopy in every-day clinical practice and research trials. Advanced endoscopic imaging techniques including high-definition endoscopes, optical magnification endoscopy, and various chromoendoscopy techniques have remarkably improved endoscopic assessment of ulcerative colitis. More recently, optical biopsy techniques with either endocytoscopy or confocal laser endomicroscopy have shown great potential in predicting several histological changes in real time during ongoing endoscopy. Here, we review current applications of advanced endoscopic imaging techniques in ulcerative colitis and present the most promising upcoming headways in this field.

How to Optimize Colon Cancer Surveillance in Inflammatory Bowel Disease Patients

Colitis-associated colorectal neoplasia (CRN) is a well-known complication of chronic inflammation of the colon either with ulcerative colitis (UC) or colonic Crohn's disease (CD). Studies have shown that inflammatory bowel disease (IBD) patients have an overall higher risk for colorectal dysplasia and cancer compared to the general population and this risk is further increased by certain associated factors, including extent of disease, duration of disease, and age at onset. In addition, other risk factors not related to IBD can also further increase the risk for CRN, such as a family history of sporadic colon cancer and a concomitant diagnosis of primary sclerosing cholangitis. The society guidelines mostly agree on the appropriate time to begin CRN surveillance but vary somewhat on the appropriate intervals between surveillance colonoscopies. In addition, there is not yet a consensus on the appropriate method for surveillance. In this review, we discuss the risk for CRN in colonic IBD, the associated factors that further increase the risk for CRN, the current surveillance guidelines and the current methods available for CRN surveillance.

Incremental diagnostic yield of chromoendoscopy and outcomes in inflammatory bowel disease patients with a history of colorectal dysplasia on white-light endoscopy

BACKGROUND AND AIMS

Chromoendoscopy (CE) identifies dysplastic lesions with a higher sensitivity than white-light endoscopy (WLE). The role of CE in the management of dysplasia on surveillance WLE in inflammatory bowel disease (IBD) remains unclear.

METHODS

A retrospective cohort of IBD patients with colorectal dysplasia on WLE who subsequently underwent CE between January 1, 2006 and August 31, 2013 was identified. Endoscopic and histologic findings were compared among the index WLE, first CE, and subsequent CE. Outcomes assessed included endoscopic lesion removal, surgery or repeat CE, and diagnosis of colorectal cancer.

RESULTS

Ninety-five index cases were identified. The median duration of IBD was 18 years (interquartile range 9.3-29.8); 78 patients had ulcerative colitis. Dysplasia was identified in 55 patients during the index WLE with targeted biopsies of 72 lesions. The first CE visualized dysplastic lesions in 50 patients, including 34 new lesions (not visualized on the index examination). Endoscopic resection was performed successfully of 43 lesions, most in the cecum/ascending colon (n = 20) with sessile morphology (n = 33). After the first CE, 14 patients underwent surgery that revealed 2 cases of colorectal cancer and 3 cases of high-grade dysplasia. Multiple CEs were performed in 44 patients. Of these, 20 patients had 34 visualized lesions, 26 of which were new findings.

CONCLUSION

Initial and subsequent CE performed in IBD patients with a history of colorectal dysplasia on WLE frequently identified new lesions, most of which were amenable to endoscopic treatment. These data support the use of serial CEs in this high-risk population.

Targeted Biopsies Identify Larger Proportions of Patients With Colonic Neoplasia Undergoing High-Definition Colonoscopy, Dye Chromoendoscopy, or Electronic Virtual Chromoendoscopy

BACKGROUND & AIMS

It is unclear what are the best and most appropriate endoscopic procedures for detecting colonic neoplasia in patients with long-term colonic inflammatory bowel disease (IBD). Dye chromoendoscopy (DCE) is the standard used in IBD surveillance colonoscopies. However, studies are needed to determine the optimal endoscopic technique for detecting dysplastic lesions. We investigated current practices used in surveillance colonoscopies by IBD gastroenterologists at a single tertiary center. We also determined the rate of neoplasia detection among different surveillance endoscopic techniques in an analysis of random or targeted biopsies.

METHODS

We collected data on 454 patients with IBD (54.5% male; mean age, 50 y; mean disease duration, 14.5 y; 55.9% with ulcerative colitis, 42.7% with Crohn's disease, and 1.3% with indeterminate colitis) who underwent surveillance colonoscopy from April 2011 through March 2014 at the University of Calgary in Canada. Subjects were examined using white-light standard-definition endoscopy (WLE), high-definition (HD) colonoscopy, virtual electronic chromoendoscopy (VCE), or DCE; random or targeted biopsy specimens were collected. Endoscopic and histologic descriptions with suspected neoplasia were recorded. Rates of neoplasia detection by the different endoscopic procedures were compared using chi-square analysis.

RESULTS

Of the patients analyzed, 27.7% had WLE endoscopy with random collection of biopsy specimens, 27.3% had HD colonoscopy with random collection of biopsy specimens, 14.1% had VCE with random collection of biopsy specimens, 0.9% had DCE with random collection of biopsy specimens, 12.8% had HD colonoscopy with collection of targeted biopsy specimens, 11.9% had VCE with collection of targeted biopsy specimens, and 5.3% had DCE with collection of targeted biopsy specimens. Neoplastic lesions were detected in 8.2% of the procedures performed in the random biopsy group (95% confidence interval, 5.6-11.7) and 19.1% of procedures in the targeted biopsy group (95% confidence interval, 13.4-26.5) (P < .001). Neoplasias were detected in similar proportions of patients by HD colonoscopy, VCE, or DCE, with targeted biopsy collection.

CONCLUSIONS

In a large cohort of IBD patients undergoing surveillance colonoscopy, targeted biopsies identified greater proportions of subjects with neoplasia than random biopsies. Targeted collection of biopsy specimens appears to be sufficient for detecting colonic neoplasia in patients undergoing HD colonoscopy, DCE, or VCE, but not WLE.

Colorectal Cancer Screening in Inflammatory Bowel Disease

Patients with long-standing ulcerative colitis (UC) or Crohn's colitis are at increased risk of developing colorectal cancer (CRC). Given that most cases of CRC are thought to arise from dysplasia, previous guidelines have recommended endoscopic surveillance with random biopsies obtained from all segments of the colon involved by endoscopic or microscopic inflammation. However, recent evidence has suggested that the majority of dysplastic lesions in patients with inflammatory disease (IBD) are visible, and data have been supportive of chromoendoscopy with targeted biopsies of visible lesions versus traditional random biopsies. This review article will discuss the risk of colon cancer in patients with IBD, as well as current recommendations for CRC screening and surveillance in patients with UC or Crohn's colitis.

Confocal Laser Endomicroscopy in Gastrointestinal and Pancreatobiliary Diseases: A Systematic Review and Meta-Analysis

Confocal laser endomicroscopy (CLE) is an endoscopic-assisted technique developed to obtain histopathological diagnoses of gastrointestinal and pancreatobiliary diseases in real time. The objective of this systematic review is to analyze the current literature on CLE and to evaluate the applicability and diagnostic yield of CLE in patients with gastrointestinal and pancreatobiliary diseases. A literature search was performed on MEDLINE, EMBASE, Scopus, and Cochrane Oral Health Group Specialized Register, using pertinent keywords without time limitations. Both prospective and retrospective clinical studies that evaluated the sensitivity, specificity, or accuracy of CLE were eligible for inclusion. Of 662 articles identified, 102 studies were included in the systematic review. The studies were conducted between 2004 and 2015 in 16 different countries. CLE demonstrated high sensitivity and specificity in the detection of dysplasia in Barrett's esophagus, gastric neoplasms and polyps, colorectal cancers in inflammatory bowel disease, malignant pancreatobiliary strictures, and pancreatic cysts. Although CLE has several promising applications, its use has been limited by its low availability, high cost, and need of specific operator training. Further clinical trials with a particular focus on cost-effectiveness and medicoeconomic analyses, as well as standardized institutional training, are advocated to implement CLE in routine clinical practice.

Colorectal Cancer in Patients With Inflammatory Bowel Disease: The Need for a Real Surveillance Program

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been widely shown. This association is responsible for 10% to 15% of deaths in patients with IBD, even if according to some studies, the risk of developing CRC seems to be decreased. An adequate surveillance of patients identified as at-risk patients, might improve the management of IBD-CRC risk. In this article we review the literature data related to IBD-CRC, analyze potential risk factors such as severity of inflammation, duration, and extent of IBD, age at diagnosis, sex, family history of sporadic CRC, and coexistent primary sclerosing cholangitis, and update epidemiology on the basis of new studies. Confirmed risk factors for IBD-CRC are severity, extent, and duration of colitis, the presence of coexistent primary sclerosing cholangitis, and a family history of CRC. Current evidence-based guidelines recommend surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis, further surveillance is decided on the basis of patient risk factors. The classic white light endoscopy, with random biopsies, is now considered unsatisfactory. The evolution of technology has led to the development of new techniques that promise to increase the effectiveness of the monitoring programs. Chromoendoscopy has already proved highly effective and several guidelines suggest its use with a target biopsy. Confocal endomicroscopy and autofluorescence imaging are currently being tested and for this reason they have not yet been considered as useful in surveillance programs.

Advanced endoscopic features of ulcerative colitis-associated neoplasias: Quantification of autofluorescence imaging

Ulcerative colitis (UC) patients are well known to carry a higher risk of developing colorectal dysplasia/cancer. However, it is hard to detect the lesion in the early phase during colonoscopy. This pilot study was conducted to analyze the endoscopic characteristics of neoplastic lesions associated with UC using advanced imaging techniques. This is a retrospective analysis of 15 colorectal neoplastic lesion obtained from 11 UC patients during remission who underwent white-light- and advanced endoscopic imaging techniques, including chromoendoscopy, narrow-band imaging and autofluorescence imaging (AFI), and were treated with surgery. These lesions were analyzed for histology, location, size, shape, color and endoscopic features. The green/red ratio was also assessed to quantify the AFI intensity. All 11 patients had extensive colitis with the median disease duration of 14.0 years. A total of 15 lesions, consisting of 8 high-grade dysplasia and 7 cancer, was mostly located in the distal colon (86.7%, 13/15) with the mean size of 8.6 mm. The shape was protruding in 46.7% (7/15), flat elevated in 40.0% (6/15) and flat in 13.3% (2/15) and the color was red in 60.0% (9/15), same colored in 33.3% (5/15) and discolored in 6.7% (1/15). The lesion predominantly showed Kudo's neoplastic pit pattern in 86.7% (13/15; 5 type IIIL, 7 type IV and 1 type VI) on chromoendoscopy and Sano's neoplastic capillary pattern (type IIIa) in 63.6% (7/11) on narrow-band imaging, but were colored purple as neoplastic lesions in only 37.5% (3/8) on AFI. Of note, the AFI green/red ratio was significantly lower in the neoplastic lesions than UC-involved areas (p=0.00014) and UC-uninvolved areas (p=0.00651) irrespective of the lesion's size and histological type. In conclusion, endoscopic analysis based on advanced imaging, in particular AFI quantitation, may be helpful to detect early stage neoplastic lesions in long standing UC. Large-scale, prospective studies are needed.

The role of endoscopy in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of chronic immune-mediated disorders of the gastrointestinal tract. It is often the result of the interaction of genetic and environmental factors. The role of endoscopy in disease surveillance is unprecedented. However, there is considerable debate in therapeutic goals in IBD patients, ranging from the resolution of clinical symptoms to mucosal healing. Furthermore, deep remission has recently been advocated for altering disease course in these patients. Additionally, neoplasia continues to be a significant cause of morbidity and mortality in IBD patients. This review discussed the role of several endoscopic techniques in assessing mucosal healing and neoplasia with emphasis on novel non-invasive endoscopic techniques.

Confocal Laser Endomicroscopy in Inflammatory Bowel Disease--A Systematic Review

BACKGROUND AND AIMS

Confocal laser endomicroscopy is an endoscopic method that provides in vivo real-time imaging of the mucosa at a cellular level, elucidating mucosal changes that are undetectable by white light endoscopy. This paper systematically reviews current indications and perspectives of confocal laser endomicroscopy for inflammatory bowel disease.

METHODS

Available literature was searched systematically for studies applying confocal laser endomicroscopy in Crohn's disease or ulcerative colitis. Relevant literature was reviewed and only studies reporting original clinical data were included. Next, eligible studies were analysed with respect to several parameters, such as technique and clinical aim and definitions of outcomes.

RESULTS

Confocal laser endomicroscopy has been used for a wide range of purposes in inflammatory bowel disease, covering assessment of inflammatory severity, prediction of therapeutic response and relapse and adenoma surveillance in patients with ulcerative colitis. Methods for measurement of the histological changes ranged from subjective grading to objective quantification analysed by computer-aided models. The studies derived their conclusions from assessment of histological features such as colonic crypts, epithelial gaps and epithelial leakiness to fluorescein.

CONCLUSIONS

Confocal laser endomicroscopy remains an experimental but emerging tool for assessment of inflammatory bowel disease. It is the only method that enables in vivo functional assessment of intestinal barrier function. There is great heterogeneity in the literature and no single approach has been validated and reproduced to the level of general acceptance.

In-vivo microscopy in the diagnosis of intestinal neoplasia and inflammatory conditions

Confocal laser endomicroscopy (CLE) is a rapidly emerging tool in endoscopic imaging allowing in-vivo microscopy of examined gastrointestinal mucosa. This review will discuss the most recent advances of confocal laser endomicroscopy in the diagnosis of intestinal neoplasia and inflammatory conditions.

Surveillance of long-standing colitis: the role of image-enhanced endoscopy

Patients with long-standing inflammatory bowel disease of the colon are at an increased risk of developing colorectal carcinoma. Surveillance programs have been implemented with the aim of detecting neoplastic lesions in an early stage. Due to limitations of conventional white light endoscopy, several new techniques to enhance the detection of dysplastic lesions in this setting have been explored. These advanced endoscopic techniques use a variety of methods to improve visualization, such as pancolonic dye-spraying (chromoendoscopy), optical filters (narrow-band imaging) and autofluorescence of mucosal tissue (autofluorescence imaging). At present, most guidelines have adopted chromoendoscopy as the preferred method for surveillance, based on several controlled studies. It is currently unknown if widespread implementation of chromoendoscopy will lead to an improved clinical outcome. This review explores the current evidence on image-enhanced endoscopic techniques used in the detection of neoplastic lesions in patients with long standing colitis.

Who and how to screen for cancer in at-risk inflammatory bowel disease patients

Inflammatory bowel diseases (IBDs) include both Crohn's disease and ulcerative colitis and both diseases are marked by inflammation within the gastrointestinal tract. Due to long-standing inflammation, IBD patients are at increased risk of colorectal cancer, especially patients with chronic inflammation, pancolitis, co-diagnosis of primary sclerosing cholangitis and a longer duration of disease. Small bowel inflammation places Crohn's patients at an increased risk of small bowel cancer. A higher risk of skin cancers, lymphomas and cervical abnormalities is also seen in IBD patients; this is likely related to both disease factors and the presence of immunosuppressive medication. This article reviews which patients are at an increased risk of IBD-associated or IBD treatment-associated cancers, when to begin screening and which screening methods are recommended.