Colorectal tumours and pit pattern

JGES guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection

Colorectal endoscopic submucosal dissection (ESD) has become common in recent years. Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also many types of precarcinomatous adenomas. It is important to establish practical guidelines in which the preoperative diagnosis of colorectal neoplasia and the selection of endoscopic treatment procedures are properly outlined, and to ensure that the actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with the guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society has recently compiled a set of colorectal ESD/endoscopic mucosal resection (EMR) guidelines using evidence-based methods. The guidelines focus on the diagnostic and therapeutic strategies and caveat before, during, and after ESD/EMR and, in this regard, exclude the specific procedures, types and proper use of instruments, devices, and drugs. Although eight areas, ranging from indication to pathology, were originally planned for inclusion in these guidelines, evidence was scarce in each area. Therefore, grades of recommendation were determined largely through expert consensus in these areas.

Two-stage optical system for colorectal polyp assessments

BACKGROUND AND AIMS

Macroscopic real-time evaluations of the histopathology and degree of invasion of colorectal polyps help to select the most suitable endoscopic treatment method. Dual-focus (DF) narrow-band imaging (NBI) is a new imaging enhancement system that uses digital and optical methods to enhance the view of blood vessels on mucosal surfaces. However, the superiority of this technique over standard imaging techniques has not been previously reported. The aim of this study was to determine whether the two-stage optical systems in a new generation of endoscopes will increase the diagnostic accuracy of colorectal polyp recognition.

METHODS

The study included 270 patients, and 386 colorectal polyps were diagnosed and removed. The polyps were assessed with white light and NBI using one- and two-stage optical systems, respectively. After being classified according to the Kudo pit pattern schemes, the polyps were removed and histopathologically verified.

RESULTS

Regarding non-neoplastic lesions (Kudo I and II), no difference was observed in the recognition of polyps when using the NBI-DF function. We observed improved accuracy in the preliminary diagnoses of Kudo IIIL lesions (from 87.16 to 90.09%, p < 0.05) and Kudo IIIS lesions (from 87.29 to 92.79%, p < 0.01). NBI-DF also increased the accuracy of preliminary diagnoses of Kudo IV lesions (from 88.24 to 94.12%, p < 0.01). The Kudo V pit patterns were also more distinct with NBI-DF imaging, increasing the diagnostic accuracy from 91.67 to 100%.

CONCLUSIONS

Using a two-stage optical system with electronic colorization of the mucosa increased diagnostic accuracy for differentiating colorectal polyps with neoplastic potential.

Usefulness of narrow-band imaging with dual-focus magnification for differential diagnosis of small colorectal polyps

BACKGROUND

Many authors have already reported the usefulness of narrow-band imaging (NBI) for the differential diagnosis of non-neoplastic and neoplastic colorectal lesions. However, it is not clear whether magnification is required for differential diagnosis. The aim of this prospective study was to clarify the clinical usefulness of a newly developed NBI system with a dual focus function (dual-focus NBI) compared with conventional white-light imaging (WLI) and NBI without magnification for distinguishing between non-neoplastic and neoplastic lesions.

PATIENTS AND METHODS

Thirty-seven consecutive patients who underwent screening colonoscopy with the novel system between July and December 2013 were analyzed. Patients with polyps >10 mm and those with polyps previously evaluated by histologic examination or colonoscopy were excluded. Lesions were diagnosed in real time with WLI, NBI without magnification, and dual-focus NBI, and then excised endoscopically. Each diagnosis was compared to that in the final histopathology reports. The primary endpoint was the diagnostic accuracy and the confidence level assigned to each modality by the endoscopists. The secondary endpoint was the differentiation ability according to the size of the lesion (≤5 and 6-10 mm).

RESULTS

In all, 100 lesions including 76 adenomatous polyps and 24 hyperplastic polyps were analyzed in 37 patients. The overall diagnostic accuracy, sensitivity, and specificity for differentiating adenomatous from hyperplastic polyps were 87.0, 89.5, and 79.2 % for WLI, 93.0, 94.7, and 87.5 % for NBI without magnification, and 94.0, 96.1, and 87.5 % for dual-focus NBI, respectively. The level of confidence was significantly different between dual-focus NBI and WLI and NBI without magnification for diminutive (≤5 mm) lesions (p < 0.001 and p < 0.01).

CONCLUSION

Dual-focus NBI is especially useful for differential diagnosis of diminutive colorectal lesions.

Advanced polypectomy and resection techniques

Most colorectal cancer arises from adenomatous polyps. This gradual process may be interrupted by screening and treatment using colonoscopy and polypectomy. Advances in imaging platforms have led to classification systems that facilitate prediction of histologic type and both stratification for and prediction of the risk of invasion. Endoscopic treatment should be the standard of care even for extensive advanced mucosal neoplasm. Technique selection is influenced by lesion features, location, patient factors, and local expertise. Postprocedural complications are more common following advanced resection and endoscopists should be familiar with risk factors, early detection methods, and management.

Prevalence of non-polypoid colorectal neoplasms in southern Brazil

BACKGROUND AND AIM

Several studies suggest that non-polypoid lesions (NPL) show higher aggressiveness than polypoid lesions, particularly depressed lesions. The present study aimed to assess the prevalence of NPL and the presence of advanced histology in a Brazilian population.

METHODS

Two thousand and sixty-seven superficial neoplastic lesions diagnosed in 1135 patients were analyzed. Lesions were classified as polypoid and non-polypoid (flat and depressed) types, and evaluated for site, size, and histology (adenoma with grade of dysplasia, or early cancer).

RESULTS

Prevalence of NPL was 46.5%. NPL predominated in the right colon (62.9%), whereas polypoid lesions were detected mainly in the left colon (53.2%) (P < 0.001). NPL had a 34% higher probability of occurring in the right colon than polypoid lesions (P < 0.001). NPL were smaller than polypoid lesions (P = 0.03). There were 208 lesions >10 mm, of which 40 (19.2%) had advanced histology: 13% (18/138) of polypoid lesions; 27.3% (18/66) of flat lesions; and 100% (4/4) of depressed lesions (P < 0.001). Among 1859 neoplasms ≤10 mm, only 18 (1%) had advanced histology, and 15 of them were depressed lesions (P < 0.001). Advanced histology was more commonly detected in NPL than in polypoid lesions (P = 0.007), with significant difference in size (P < 0.001). NPL showed more advanced histology than polypoid lesions (OR 2.06; P = 0.01), especially depressed lesions (OR 36.35; P < 0.001). Among all neoplasms, the prevalence of depressed lesions was 2.2%.

CONCLUSION

NPL showed high prevalence and higher aggressiveness than polypoid lesions, especially the depressed type.

Management of colonic polyps and the NHS Bowel Cancer Screening Programme

This article describes the NHS Bowel Cancer Screening Programme and the management of large colonic polyps, many of which are diagnosed and managed successfully during bowel cancer screening, in addition to non-endoscopic management options.

Malignancy in large colorectal lesions

CONTEXT

The size of colorectal lesions, besides a risk factor for malignancy, is a predictor for deeper invasion objectives: To evaluate the malignancy of colorectal lesions ≥20 mm.

METHODS

Between 2007 and 2011, 76 neoplasms ≥20 mm in 70 patients were analyzed.

RESULTS

The mean age of the patients was 67.4 years, and 41 were women. Mean lesion size was 24.7 mm ± 6.2 mm (range: 20 to 50 mm). Half of the neoplasms were polypoid and the other half were non-polypoid. Forty-two (55.3%) lesions were located in the left colon, and 34 in the right colon. There was a high prevalence of III L (39.5%) and IV (53.9%) pit patterns. There were 72 adenomas and 4 adenocarcinomas. Malignancy was observed in 5.3% of the lesions. Thirty-three lesions presented advanced histology (adenomas with high-grade dysplasia or early adenocarcinoma), with no difference in morphology and site. Only one lesion (1.3%) invaded the submucosa. Lesions larger than 30 mm had advanced histology (P = 0.001). The primary treatment was endoscopic resection, and invasive carcinoma was referred to surgery. Recurrence rate was 10.6%.

CONCLUSIONS

Large colorectal neoplasms showed a low rate of malignancy. Endoscopic treatment is an effective therapy for these lesions.

Finding sessile serrated adenomas: is it possible to identify them during conventional colonoscopy?

BACKGROUND AND AIM

Proximal colorectal cancer may arise from sessile serrated adenomas (SSAs). Recognition of these lesions during colonoscopy can optimize the endoscopic approach. We aimed to identify specific endoscopic features of SSA with conventional colonoscopy.

METHODS

Patients undergoing screening colonoscopies from January 2011 to September 2012, in whom colonic polyps were found, were prospectively included in our study. Polyp morphology, location, polyp pit pattern (Kudo classification), and other previously reported features of SSA were evaluated. Histological examination was conducted independently by two pathologists. Multivariate analysis was performed to identify independent predictors of SSA.

RESULTS

A total of 272 patients were included, and 440 polyps were evaluated (1.6 polyps per patient). Thirty-four polyps (8%) were SSA, 135 (31%) hyperplastic, and 249 (56%) adenomas. The most prevalent endoscopic features of SSA were right-side location (94%), type II Kudo pit pattern (91%), mucus cap (41%), flat morphology (29%) and red-colored surface (26%). Multivariate analysis revealed that flat morphology (p = 0.002, OR = 3.81 CI 1.53-9.09), red-colored surface (p < 0.001, OR = 12.97 CI 4.43-37.69), right-side location (p < 0.001, OR = 22.21 CI 5.09-135.94) and mucus cap (p < 0.001, OR 8.77 CI 3.76-20.44) were independent predictors of SSA.

CONCLUSION

We were able to identify specific features of SSA during conventional colonoscopy, which may help to identify, and therefore to optimize the endoscopic approach of these lesions.

Accuracy of in vivo colorectal polyp discrimination by using dual-focus high-definition narrow-band imaging colonoscopy

BACKGROUND

Discriminating neoplastic from non-neoplastic polyps can significantly reduce the cost of colonoscopy. The American Society for Gastrointestinal Endoscopy (ASGE) recently set threshold levels for optical diagnostic accuracy to be acceptable for clinical use.

OBJECTIVE

In this study, we compare a novel colonoscope capable of dual-focus imaging with standard colonoscopy with respect to the ASGE guidelines.

SETTING

An academic medical center ambulatory surgical center.

PATIENTS AND INTERVENTIONS

Patients at average risk were randomized to standard colonoscopy (Olympus CF-H180 and Exera II 180 colonoscopes, Olympus America, Center Valley, Pa) or dual-focus colonoscopy (Olympus CF-HQ190 and Exera III 190 colonoscopes, Olympus America). All polyps were given an optical diagnosis and compared with histology.

RESULTS

A total of 600 patients were consented and 522 completed all aspects of the procedure. A total of 927 polyps were analyzed. Optical diagnostic accuracy was 79% (95% confidence interval, 74%-83%) for the 190 and 77% (95% confidence interval, 73%-81%) for the 180 colonoscope. Adenoma detection rates were also similar between the 2 groups (50% for the 190 vs 52% for the 180 colonoscope). For small distal rectosigmoid polyps with a high confidence diagnosis, the negative predictive value for adenoma was 96% (range 89%-99%) for the 180 in the narrow-band imaging (NBI) mode and 97% (range 88%-99%) for the 190 colonoscope in NBI mode. Agreement of surveillance intervals by using optical diagnosis was 94% to 95% for all modalities (180 and 190 colonoscopes, white light imaging, NBI).

LIMITATIONS

Our study evaluated the accuracy of the 180 and 190 colonoscopes at a center with already-established expertise in endoscopic imaging.

CONCLUSIONS

Both traditional and new dual-focus colonoscopes provide highly accurate optical polyp discrimination. There was no difference between the 2 systems in terms of discrimination or adenoma detection. Both systems are consistent with ASGE guidelines for optical diagnosis of selected colorectal polyps without histological confirmation.

Endoscopic submucosal dissection versus transanal endoscopic microsurgery for the treatment of early rectal cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are minimally invasive procedures that can be used to treat early rectal cancer.

OBJECTIVE

The aim of this study was to compare clinical efficacy between ESD and TEM for the treatment of early rectal cancer.

METHODS

Between July 2008 and August 2011, 24 patients with early rectal cancers were treated by ESD (11) or TEM (13) at the Cancer Institute of São Paulo University Medical School (São Paulo, Brazil). Data were analyzed retrospectively according to database and pathological reports, with respect to en bloc resection rate, local recurrence, complications, histological diagnosis, procedure time and length of hospital stay.

RESULTS

En bloc resection rates with free margins were achieved in 81.8 % of patients in the ESD group and 84.6 % of patients in the TEM group (p = 0.40). Mean tumor size was 64.6 ± 57.9 mm in the ESD group and 43.9 ± 30.7 mm in the TEM group (p = 0.13). Two patients in the TEM group and one patient in the ESD group had a local recurrence. The mean procedure time was 133 ± 94.8 min in the ESD group and 150 ± 66.3 min in the TEM group (p = 0.69). Mean hospital stay was 3.8 ± 3.3 days in the ESD group and 4.08 ± 1.7 days in the TEM group (p = 0.81).

LIMITATIONS

This was a non-randomized clinical trial with a small sample size and selection bias in treatment options.

CONCLUSION

ESD and TEM are both safe and effective for the treatment of early rectal cancer.

How big is this neoplasia? live colonoscopic size measurement using the Infocus-Breakpoint

Colonoscopy is the reference medical examination for early diagnosis and treatment of colonic diseases. This minimally invasive technique allows endoscopists to explore the colon cavity and remove neoplasias - abnormal growths of tissue - which may develop into malignant tumors. The size, shape and appearance of a neoplasia are essential cues for diagnostic. However, the size is difficult to estimate because the absolute scale of the observed tissue is not directly conveyed in the 2D colonoscopic images. An erroneous size estimate may lead to inappropriate treatment. There currently exist no solutions to reproducible neoplasia size measurement adapted to colonoscopy. We propose a colonoscopic size measurement system for neoplasias. By using a simple planar geometry, the key technical problem is reduced to resolving scale. Our core contribution is introducing the Infocus-Breakpoint (IB) that allows us to resolve scale from a regular colonoscopic video. We define the IB as the lower limit of the colonoscope's depth of field. The IB corresponds to a precise colonoscope to tissue distance, called the reference depth, which we calibrate preoperatively. We detect the IB intraoperatively thanks to two novel modules: deformable Blur-Estimating Tracking (BET) and Blur-Model Fitting (BMF). With our system, the endoscopist may interactively measure the length and area of a neoplasia in a 2D colonoscopic image directly. Our system needs no hardware modification to standard monocular colonoscopes, yet reaching a size measurement accuracy of the order of a millimeter, as shown on several phantom and patient datasets.

[Incidental findings in gastroscopy and colonoscopy]

For many specific and nonspecific gastrointestinal symptoms, endoscopic diagnostic procedures play an important role. Gastroscopy and colonoscopy are easily available diagnostic and interventional procedures with low risk. The technical development of gastrointestinal endoscopy has led to an improvement in diagnostics and therapy. In addition to frequent and expected findings, incidental findings may occur. The incidental findings can distinguish rare diseases of unexpected diagnoses. Rare diagnoses usually require an individualized therapy. Unexpected diagnoses can take place during (not properly detected) or after an endoscopy (overlooked or newly appeared) occur. This overview deals with the question of how to minimize unexpected diagnoses and how to diagnose and treat incidental findings.

Training methods and models for colonoscopic insertion, endoscopic mucosal resection, and endoscopic submucosal dissection

Colonoscopic examination is considered an effective examination for the detection of colorectal cancers. Additionally, early colorectal cancers can be resected using endoscopic techniques such as endoscopic mucosal resection and endoscopic submucosal dissection. However, those examinations and treatments need special techniques. Various training methods are practiced to acquire such endoscopic techniques throughout the world. In clinical cases, magnetic positioning devices help endoscopic insertion by less experienced endoscopists. There is a physical model made by polyvinyl chloride and a virtual simulator for training of colonoscopic insertion. Various techniques including a method to apply pressure to the abdomen and consideration for patient's pain can be trained using these models. In view of extensive training of endoscopic mucosal resection and endoscopic submucosal dissection, animal models are useful and actually used. Live animal models of minipig, which entails blood flow, are ideal and used frequently, but are cumbersome to prepare. On the other hand, ex vivo animal models using intestine of porcine and bovine are convenient for preparation and less expensive. Unique ex vivo animal models with blood flow have been developed recently and techniques for hemostasis can be practiced. With respect to a method of training for colorectal endoscopic submucosal dissection, a stepwise system has been adopted throughout the world. Thus, first they observe the expert's technique, then practice training of animal models, and finally, they perform clinical rectal cases. The system is useful for a safe and definite procedure. In this review, we reveal various training methods for colonoscopic examinations and treatments.

Advances, problems, and complications of polypectomy

The major role of colonoscopy with polypectomy in reducing the incidence of and mortality from colorectal cancer has been firmly established. Yet there is cause to be uneasy. One of the most striking recent findings is that there is an alarmingly high incomplete polyp removal rate. This phenomenon, together with missed polyps during screening colonoscopy, is thought to be responsible for the majority of interval cancers. Knowledge of serrated polyps needs to broaden as well, since they are quite often missed or incompletely removed. Removal of small and diminutive polyps is almost devoid of complications. Cold snare polypectomy seems to be the best approach for these lesions, with biopsy forcep removal reserved only for the tiniest of polyps. Hot snare or hot biopsy forcep removal of these lesions is no longer recommended. Endoscopic mucosal resection and endoscopic submucosal dissection have proven to be effective in the removal of large colorectal lesions, avoiding surgery in the majority of patients, with acceptably low complication rates. Variants of these approaches, as well as new hybrid techniques, are being currently tested. In this paper, we review the current status of the different approaches in removing polypoid and nonpolypoid lesions of the colon, their complications, and future directions in the prevention of colorectal cancer.

Does magnifying narrow-band imaging or magnifying chromoendoscopy help experienced endoscopists assess invasion depth of large sessile and flat polyps?

BACKGROUND

Distinguishing deep submucosa (SM) from superficial SM cancer in large sessile and flat colorectal polyps (>2 cm) is crucial in making the most appropriate therapeutic decision. We evaluated the additional role of magnifying narrow-band imaging (NBI) and magnifying chromoendoscopy (MCE) in assessing the depth of invasion in large sessile and flat polyps in comparison to morphological evaluation performed by experienced endoscopists.

METHODS

From May 2011 to December 2011, a total of 85 large sessile and flat polyps were analyzed. Endoscopic features of the polyps were independently evaluated by experienced endoscopists. Subsequently, the polyps were observed using magnifying NBI and MCE.

RESULTS

A total of 58 intramucosal lesions and 27 SM cancers (five superficial and 22 deep) were identified. The diagnostic accuracy of the experienced endoscopists, NBI, and MCE were 92.9, 90.6, and 89.4 %, respectively, for deep SM cancer. In combination with NBI or MCE, the diagnostic accuracy of the experienced endoscopists did not change significantly for deep SM cancer, with an accuracy of 95.3 % for both NBI and MCE.

CONCLUSIONS

Conventional colonoscopy can differentiate superficial from deep SM cancers with an accuracy of as high as 92.9 % in large sessile and flat polyps. Further diagnostic strategies are required in order to precisely assess the depth of invasion, especially in large colorectal polyps.

Impact of clinical experience on type V pit pattern analysis using magnifying chromoendoscopy in early colorectal cancer: a cross-sectional interpretation test

Background

Although type V pit pattern analysis is effective in determining the invasion depth of early colorectal cancers, the clinical results may vary because findings are operator-dependent. This study aimed to assess the benefits of type V pit pattern analysis in estimating the invasion depth using magnifying chromoendoscopy compared to that with conventional colonoscopy.

Methods

A cross-sectional interpretation test involving 32 endoscopists with varying levels of experience performing colonoscopies was conducted. Fifty histopathologically diagnosed cases of intramucosal or submucosal cancer were selected retrospectively. The lesions were classified as superficial or deep by the endoscopists, based on magnifying chromoendoscopic and non-magnifying endoscopic images. The endoscopists were classified into 3 groups based on the number of colonoscopies performed: I (<500), II (501–5000), and III (>5000). Differences in the interpretation of invasion depth between group III and groups I and II were assessed using the Mann–Whitney U test.

Results

There was no significant difference in the median number of correct interpretations using non-magnifying endoscopic images among the groups. However, a significant difference (P = 0.007) was observed between the results of groups III and I when the analysis was performed using magnifying chromoendoscopic images.

Conclusions

When performed by less experienced endoscopists, pit pattern analysis of colonic lesions using magnifying chromoendoscopy is not a reliable modality for estimating invasion depth in early colorectal cancer.

Prevention of colonic spasm using L-menthol in colonoscopic examination

PURPOSE

The detailed efficacy of intraluminal L-menthol for preventing colonic spasm is not known. The aim of this study was to evaluate the effectiveness of L-menthol in preventing colonic spasm during colonoscopy.

METHODS

We analyzed 65 patients (mean age: 71.7 years; 49 men and 16 women) who were administered 0.8% L-menthol (MINCLEA, Nihon Seiyaku, Tokyo, Japan) intraluminally for severe colonic spasm during colonoscopic examination at Kyoto Prefectural University of Medicine between February 2012 and May 2013. The efficacy of L-menthol was defined as the absence of colonic spasm during a period of 30 s, and its effect was evaluated at 30 s, 1 min, and 5 min after administration. Additionally, various characteristics of these patients were analyzed. Twenty-seven patients with severe colonic spasm were administered intraluminal water and assessed as controls.

RESULTS

L-Menthol was effective in preventing colonic spasms in 60.0%, 70.8%, and 46.5% of patients at 30 s, 1 min, and 5 min, respectively. In contrast, water was effective in 22.2%, 29.6%, and 48.1% of patients at 30 s, 1 min, and 5 min, respectively. There was a significant difference about the efficacy at 30 s and 1 min between L-menthol and water (P = 0.0009, P = 0.0006).

CONCLUSIONS

L-Menthol (0.8%) was effective in preventing colonic spasm during colonoscopic examination.

Proposal of a new 'resect and discard' strategy using magnifying narrow band imaging: pilot study of diagnostic accuracy

BACKGROUND AND AIM

A 'resect and discard' strategy using non-magnifying narrow band imaging (N-NBI) has been proposed for reducing screening colonoscopy costs, but it does not take into consideration advanced histology and magnifying NBI (M-NBI) that can potentially further improve the 'resect and discard' strategy. We conducted a pilot study to investigate the feasibility of M-NBI for the new 'resect and discard' strategy with consideration for advanced histology.

METHODS

The present study involved 63 patients. For each polyp, optical diagnosis was independently made using N-NBI and M-NBI, a decision (discard or send for pathology) was made based on the M-NBI findings, and histological and optical diagnosis results were compared.

RESULTS

Sensitivity, specificity and accuracy (95% confidence interval) of M-NBI for lesions with advanced histology were 1.00 (0.36-1.00), 0.92 (0.91-0.92) and 0.92 (0.90-0.92), respectively. Whereas the management of 86% of small polyps could be decided without formal histopathology, lesions with advanced histology were not discarded using M-NBI. The diagnostic accuracy of M-NBI in distinguishing neoplastic from non-neoplastic lesions was higher than that of N-NBI.

CONCLUSIONS

We propose a new resect and discard strategy with advanced histology using M-NBI that is a promising strategy to reduce the costs of histopathology and to minimize the risk of discarding important lesions.

Is it possible to discriminate between neoplastic and nonneoplastic lesions in ulcerative colitis by magnifying colonoscopy?

BACKGROUND

Colitis-associated cancer/dysplasia is an intestinal tract condition that can affect the life expectancy of patients with ulcerative colitis. It is often difficult to detect neoplastic lesions. This study evaluated whether any endoscopic features are effective for distinguishing colitis-associated cancer/dysplasia from nonneoplastic lesions in patients with ulcerative colitis.

METHODS

The study involved 52 patients with 61 lesions treated at Hiroshima University Hospital between September 1999 and May 2012: 10 patients with 11 dysplastic lesions, 5 patients with 5 intramucosal carcinomas, 3 patients with 3 submucosal carcinomas, and 34 patients with 42 nonneoplastic lesions. All patients had undergone targeted biopsy. Endoscopic findings were compared between patients with biopsy-determined neoplasia and those with biopsy-determined nonneoplasia. Multivariate regression analysis was performed to identify magnifying chromocolonoscopy features predictive of neoplasia.

RESULTS

No significant difference was found in conventional endoscopy features between the neoplastic and nonneoplastic lesions. Under magnifying chromocolonoscopy, the pit density of the neoplastic lesions was found to be significantly greater than that of the nonneoplastic lesions (89% [17/19] versus 60% [25/42], respectively). Pit margins were more frequently irregular in the neoplastic lesions than in the nonneoplastic lesions (63% [12/19] versus 33% [14/42], respectively).

CONCLUSIONS

In differentiating between colitis-associated neoplastic and nonneoplastic lesions, focus should be on the high residual density of pits and irregular pit margins observed under magnifying chromocolonoscopy.

A review of image-enhanced endoscopy in the evaluation of colonic polyps

The practice of colonoscopy has changed considerably over the last decade. The growth of image-enhanced endoscopy have altered our concepts of how we perform colonoscopy. This article examines the evidence base behind these techniques and looks at where future research needs to be directed.

Colorectal dysplasia in inflammatory bowel disease: a clinicopathologic perspective

Surveillance for neoplasia in colitis is the most challenging diagnostic colonoscopic procedure. The detection and treatment of colorectal dysplasia in inflammatory bowel disease remain problematic to the point that unsuspected colorectal cancers (CRCs) are still identified. Excellent bowel preparation and use of high-resolution colonoscopes with chromoendoscopy facilitate the detection and characterization of subtle neoplasia. This approach is superior to taking random biopsy specimens and should be the standard of care for surveillance but requires adequate training. Suspicious lesions should be assessed carefully and described using objective terminology. The terms dysplasia-associated lesions/masses and flat dysplasia are best avoided because they may be open to misinterpretation. Most suspicious lesions detected during surveillance can be removed endoscopically, precluding the need for surgery. Nevertheless, endotherapy in colitis can be difficult as a result of underlying inflammation and scarring. Lesions that are not endoscopically resectable need to be removed surgically, although the possibility that some lesions might be amenable to local resection (including lymphadenectomy) rather than subtotal colectomy may need to be re-evaluated. Despite surveillance programs, patients still present clinically with CRC. This may occur because lesions are missed (possibly because of the failure to use optimal techniques), lesions are not adequately removed, patients fail to return for colonoscopy, or CRCs arise rapidly in mucosa that is minimally dysplastic and the CRCs are not recognized as being potentially invasive even on biopsy. Future advances in, for example, stool DNA assays, use of confocal endomicroscopy, or use of endoscopic ultrasound, may help in the identification of high-risk patients and the assessment of dysplastic lesions.

Ability of a novel blue laser imaging system for the diagnosis of colorectal polyps

BACKGROUND

A new endoscope system with a laser light source, blue laser imaging (BLI), has been developed by Fujifilm that allows for narrow-band light observation. The aim of the present study was to evaluate the utility of BLI for the diagnosis of colorectal polyps.

METHODS

We retrospectively analyzed 314 colorectal polyps that were examined with BLI observation at Kyoto Prefectural University of Medicine between September 2011 and January 2013. The surface and vascular patterns of polyps detected by published narrow-band imaging magnification: Hiroshima classification were used. Correlations were determined between the classifications and the histopathological diagnoses. Additionally, the ability of BLI without magnification to differentiate between neoplastic or non-neoplastic polyps was analyzed.

RESULTS

A total of 41 hyperplastic polyps, 168 adenomas, 80 intramucosal cancer, 11 shallowly invaded submucosal cancer, and 14 deeply invaded submucosal cancer were analyzed.Hyperplastic polyp was observed in 100% of Type A lesions (39 lesions), adenoma was observed in 89.3% of Type B lesions (159 lesions), intramucosal cancer and shallowly invaded submucosal cancer was observed in 69.6% of Type C1 (92 lesions) and in 84.6% of Type C2 (13 lesions), and deeply invaded submucosal cancer was observed in 81.8% of Type C3 lesions (11 lesions). The overall diagnostic accuracy of BLI with magnification was 84.3%. Additionally, the diagnostic accuracy of BLI without magnification for differentiating between neoplastic and non-neoplastic polyps <10 mm in diameter was 95.2%, which was greater than that of white light (83.2%).

CONCLUSION

BLI was useful for the diagnosis of colorectal polyps.

Complementation by argon plasma coagulation after endoscopic piecemeal resection of large colorectal adenomas

OBJECTIVE

To evaluate the efficacy of complement by argon plasma coagulation to reduce the rate of residual or recurrent tumor after complete endoscopic piecemeal resection of large sessile colorectal adenomas.

METHODS

INCLUSION CRITERIA

patients with large sessile colorectal adenomas (e" 20 mm), without morphological signs of deep infiltration, submitted to complete endoscopic piecemeal resection studied with chromoendoscopy and magnification of images. Patients were randomized into two groups: group 1 - no additional procedure, and group 2 - complementation by argon plasma coagulation. follow-up colonoscopy was performed at three, six and 12 months postoperatively. We evaluated the rate of local recurrence or residual malignancy.

RESULTS

The study included 21 patients, eleven in group 1 and ten in group 2. There were two local recurrences or residual tumors in each group, detected at three months follow-up.

CONCLUSION

Complementation by argon plasma coagulation after apparent complete endoscopic piecemeal resection of large sessile colorectal adenomas does not seem to reduce the occurrence of residual adenomatous lesions or local recurrence.

Value of NICE classification in differentiating colorectal neoplastic and non-neoplastic polyps

AIM: To systemically evaluate the value of narrow-band imaging international colorectal endoscopic (NICE) classification in differentiating neoplastic and non-neoplastic colorectal polypoid lesions.

METHODS: A series of 60 white-light endoscopy (WLE) and narrow-band imaging (NBI) images of colorectal polyps were studied. They were subjected to 10 raters to predict the pathology using NICE classification, and those 10 raters were divided into 2 groups, NBI-experienced group and NBI-beginner group. The histopathology was used as the gold standard to calculate the specificity, sensitivity, accuracy, positive predictive value and negative predictive value of NICE classification in predicting pathology of colorectal polyps, and compare if there were significant differences between the two groups in sensitivity, specificity and accuracy.

RESULTS: The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of NICE classification in differentiating colorectal neoplastic and non-neoplastic polyps were 99.33%, 64.67%, 82.00%, 74.40% and 98.95%, respectively, in the NBI-experienced group, and 91.33%, 66.00%, 78.67%, 73.70% and 90.16%, respectively, in the NBI-beginner group. There was no significant difference between the two groups in sensitivity, specificity and accuracy. The interobserver agreement was good.

CONCLUSION: Use of NICE classification in NBI colonoscopy could effectively distinguish neoplastic and non-neoplastic colorectal polyps, and it could be used by both NBI experienced endoscopists and NBI beginners.

Association of gallbladder polyp with the risk of colorectal adenoma

Background/Aims

Gallbladder polyps and colorectal adenomas share many common risk factors; however, their association has never been studied. The aim of this study was to investigate this association in asymptomatic healthy subjects.

Methods

Consecutive asymptomatic subjects who underwent both screening colonoscopy and abdominal ultrasonography at Kyung Hee University Hospital in Gang Dong between July 2010 and April 2011 were prospectively enrolled. The prevalence of colorectal adenoma was compared between subjects with or without gallbladder polyps. Furthermore, a logistic regression analysis was performed to determine the independent risk factors for colorectal adenoma in these subjects.

Results

Of the 581 participants, 55 presented with gallbladder polyps and 526 did not have gallbladder polyps. Participants with gallbladder polyps showed a trend toward a higher prevalence of colorectal adenoma than those without gallbladder polyps (52.7% vs. 39.2%, P=0.051). Although the result was not statistically significant, gallbladder polyps were found to be a possible risk factor for colorectal adenoma (odds ratio=1.796, 95% confidence interval=0.986-3.269, P=0.055), even after adjusting for potential confounding factors. There was no difference observed in colorectal adenoma characteristics between the two groups.

Conclusions

Our results suggest a possible association between gallbladder polyps and colorectal adenomas. Future studies with larger cohorts are warranted to further investigate this matter.

Advanced imaging in colonoscopy and its impact on quality

Detecting and resecting colonic polyps during endoscopy has been shown to reduce CRC. At the same time, endoscopy has faced substantial technical improvements and continues to undergo major changes. Detection of colorectal neoplasias is facilitated by using high-definition endoscopy, and characterization of lesions is more accurate by using virtual CE. High-definition endoscopy has found widespread use, whereas virtual CE is still more often used in tertiary centers and for high-risk patient groups. Endomicroscopy has opened the door for in vivo histology and functional as well as molecular imaging. Thorough training of the endoscopists is necessary, and redefined reimbursement codes may help make these techniques available in the clinical arena for high-risk patients who are most probable to benefit from the more advanced diagnostic endoscopy techniques. Over recent years, there has also been an increasing push by healthcare payors and providers to improve the quality of healthcare services. The ultimate goal of monitoring quality measures is to improve the overall health of the population and, for colon cancer screening, to reduce the incidence and mortality of colon cancer. However, the development of an appropriate quality measure and ensuring the accuracy of the data on which we base our efforts are among the first challenges that we must meet (Table 1). The continued technologic advancements in colonoscopy and endoscopic imaging may result in improvements in the quality of colonoscopy and should lead to a decrease in the incidence and mortality from colon cancer.

The ability of a novel blue laser imaging system for the diagnosis of invasion depth of colorectal neoplasms

BACKGROUND

Fujifilm has developed a novel endoscope system with two kinds of lasers that enables us to allow narrow-band light observation with blue laser imaging (BLI). The aim of this study was to evaluate BLI magnification in comparison with narrow-band imaging (NBI) magnification for the diagnosis of colorectal neoplasms.

METHODS

This was a multicenter open study. A total of 104 colorectal neoplasms were examined with BLI and NBI magnifications in Kyoto Prefectural University of Medicine and Fukuoka University Chikushi Hospital. Vascular and surface patterns of tumors under BLI magnification were compared with those under NBI magnification, using a published NBI classification. The main outcome was the correlation between the NBI classification diagnosed by BLI or NBI magnification and the histopathological analyses.

RESULTS

Sixty-two cases of adenoma, 34 cases of intramucosal cancer and shallowly invaded submucosal cancer, and eight cases of deeply invaded submucosal cancer were diagnosed. The diagnostic accuracy of BLI magnification in the NBI classification was 74.0 % (77/104), similar to that of NBI magnification (77.8 %). The consistency rate between BLI and NBI magnification in the NBI classification was 74.0 %. Concerning image evaluation, the interobserver variability of two expert endoscopists (N.Y. and T.H.) in BLI magnification was κ = 0.863. On the other hand, the intraobserver variability of the two endoscopists was κ = 0.893 (N.Y.) and 0.851 (T.H.).

CONCLUSIONS

BLI magnification by laser source could predict histopathological diagnosis and invasion depth of colorectal neoplasms. The diagnostic effectiveness of this method was similar to that of NBI magnification.

Endoscopic submucosal dissection: experience in an Australian tertiary center

BACKGROUND

Endoscopic submucosal dissection (ESD) is a technique for en bloc resection of superficial tumors of the gastrointestinal tract. In contrast to Japan and other Asian countries, few data are available in Western countries. The objective of the current study was to evaluate the experience of ESD in a single Australian tertiary center.

METHODS

The patient features, outcomes and complications of ESD of 20 lesions in 18 patients at a single center between 2008 and 2012, were evaluated retrospectively.

RESULTS

Twenty lesions, in 18 patients of median age 69.5 years, were resected with ESD. Ten patients had gastric lesions (of whom two had two synchronous lesions), four patients had rectal lesions, one had a colonic lesion, one had a duodenal lesion and two had esophageal lesions. The median (range) lesion size was 2.5 (0.5-6.5) cm. In the entire cohort, en bloc resection occurred in 80% cases and complete histological resection was achieved in 60% cases. Significant bleeding requiring repeat endoscopy and transfusion occurred in two cases and microscopic perforation occurred in 1 case. Surgery for unsuccessful ESD was pursued without complication in 6 cases. There were two recurrences during follow up of median 36 months, both of which occurred in cases of gastric ESD and one of which (carcinoid) occurred after surgery.

CONCLUSIONS

ESD appears feasible in an Australian population. It should however be contemplated in carefully selected patients whilst there is refinement of pre-treatment diagnosis, the ESD technique and the management of its complications.

Endoluminal ultrasound biomicroscopy as a reliable tool for in vivo assessment of colonic inflammation in rats

PURPOSE

Endoscopic ultrasound (EUS) imaging of the colon is an important diagnostic tool for early neoplasia, although usually restricted to the rectum in inflammatory bowel disease (IBD). This study aimed to evaluate the ability of an endoluminal ultrasound biomicroscopic (eUBM) system to detect and characterize lesions simulating Crohn's disease in the colon of rats in vivo.

METHODS

Colitis was induced with trinitrobenzene sulfonic acid instillated in the distal colon. Eighteen Wistar rats were submitted to eUBM in three time points: week 1 group (18 animals examined on day 3 after colitis induction), week 2 group (12 animals on days 3 and 10), and week 3 group (7 animals on days 3, 10, and 17). This design yielded distinct inflammation intensities. Three untreated rats were used for acquisition of control images. Scores were used for comparison with histology.

RESULTS

Scores for eUBM and histology in the different moments of examination achieved a Spearman's rank correlation coefficient of 0.87 (p < 0.001). Findings of wall thickening presented positive predictive value (PPV) and sensitivity of 94 and of 100 %, respectively. Superficial and deep ulcers presented a PPV of 89 and 80 %, respectively, and negative predictive values of 100 and 85 %, respectively.

CONCLUSION

Accurate detection and analysis of the lesions was achieved. The model is essential for the clinical development of the technique and a reproducible method for the evaluation of experimental colitis. eUBM might be applicable in different segments of the gut, developing into a novel adjunct method for IBD evaluation.

Clinicopathologic features of hyperplastic/serrated polyposis syndrome in Japan

BACKGROUND AND AIM

Hyperplastic/serrated polyposis syndrome (HPS) is a condition characterized by multiple hyperplastic/serrated colorectal polyps. The risk of colorectal cancer (CRC) is increased in HPS. The clinicopathologic characteristics of HPS in Japanese patients are unknown. The aim of this study is to clarify the clinicopathologic features of HPS in Japanese patients.

METHODS

We retrieved records of patients diagnosed with HPS between April 2008 and March 2011 from the endoscopy database of Hiroshima University Hospital. In addition, we mailed a questionnaire to the hospital's 13 affiliated hospitals in July 2012. Data collected from the database and questionnaires included patient age, sex, number of hyperplastic/serrated polyps and tubular adenomas, size of the largest polyp, polyp location, resection for polyps, coexistence of HPS with CRC, and the diagnostic criterion met.

RESULTS

Of the 73,608 patients who underwent colonoscopy, 10 (0.014%) met the criteria for HPS. The mean age of these patients was 58.3 years, and 6 (60%) were men. No subjects had a first-degree relative with HPS. Four (40%) HPS patients had more than 30 hyperplastic/serrated polyps, and average size of the largest polyp was 19 mm. Three (30%) HPS patients had coexistence of HPS with CRC. In these 3 patients, polyps were observed throughout the colorectum.

CONCLUSIONS

Although HPS was a rare condition in the overall study population, patients with the disease may have high risk of CRC. HPS should be diagnosed correctly and followed up carefully.

A case of rectal tumor in which the shape altered with regression in short period

Background

Histological regression of solid tumors in adults receiving no treatment is rare. Specifically, spontaneous partial and complete regression of colorectal cancers account for less than 2% of such cases and those without metastasis are exceedingly rare.

Case presentation

A 60-year-old male underwent total colonoscopy following a positive fecal occult blood test at the referring hospital. A flat elevated lesion with central reddish depression, 10 mm in diameter, was detected in the lower rectum. Biopsy results from the referring hospital showed a well-differentiated adenocarcinoma and the patient was referred to our hospital for diagnosis and treatment. Preoperative colonoscopy was performed to determine the therapeutic strategy; however, we found only scar tissue and there were no endoscopic features to suggest malignancy. Biopsy from the scar revealed normal rectal mucosa and we performed diagnostic endoscopic submucosal resection with a ligation device (ESMR-L) one week later. The resected specimen showed a 1 mm well-differentiated adenocarcinoma with low-grade atypia and no lymphovascular invasion. The macroscopic type was 0-IIb, the depth of invasion was intramucosal, and the vertical and lateral margins were negative. There has been no evidence of recurrence for 18 months following treatment.

Conclusion

We report a case of a rectal tumor showing regression over a short period without treatment. Spontaneous regression of malignant tumors is a rare and unexplained phenomenon. Further research and understanding of the mechanism holds the key for treatment and prevention of cancer in the future.

Magnifying Endoscopic Findings Can Predict Clinical Outcome during Long-Term Follow-Up of More Than 12 Months in Patients with Ulcerative Colitis

Background and Aims. To explore the association of magnifying endoscopic (ME) findings with histopathology and relapse in ulcerative colitis (UC). Methods. Forty-six patients with UC underwent ME with narrow band imaging (NBI) and crystal violet staining and were followed for more than 12 months. ME findings with vital staining were classified into ME-A, regular arrangement of round to oval pits; ME-B, irregular arrangement with/without enlarged spaces between even pits; ME-C, irregular pits in size and shape with more irregular arrangement of pits; and ME-D, disrupted or disappeared pits. NBI-guided ME features of microvascular pattern (MVP) were divided into the MVP-regular and MVP-irregular type. Results. There were 5, 24, 10, and 7 cases of ME-A, ME-B, ME-C, and ME-D grade, respectively, while there were 21 and 25 of MVP-regular and MVP-irregular type, respectively. ME classifications were significantly associated with Matts endoscopic grade. ME classifications and MVP types were significantly associated with each pathognomonic microscopic feature of severe mucosal inflammation, crypt abscess, and goblet cell depletion. There were significant differences in the percentages of remission among ME classifications and between MVP types. Conclusion. ME findings can be predictive of relapse in UC and reliable for in vivo histopathological assessment.

Risk factors for vertical incomplete resection in endoscopic submucosal dissection as total excisional biopsy for submucosal invasive colorectal carcinoma

PURPOSE

Endoscopic submucosal dissection (ESD) for colorectal tumor is a minimally invasive treatment. Histologic information obtained from the entire ESD specimen is important for therapy selection in submucosal invasive colorectal carcinoma (SMca). This study aimed to identify risk factors for vertical incomplete resection (vertical margin-positive [VM+]) when ESD was performed as total excisional biopsy for SMca.

METHODS

From June 2003 through December 2011, 78 SMca cases were resected by ESD at Hiroshima University Hospital. Patient and tumor characteristics, intraoperative variables, and histopathology were compared between the VM+ group and the vertical complete resection (vertical margin-negative) group. The ability of magnifying endoscopy (ME) and endoscopic ultrasonography (EUS) to predict VM+ was assessed.

RESULTS

ESD resulted in VM+ in eight cases (10.3 %), with a greater percentage invading to a depth of ≥2,000 vs. <2,000 μm (P = 0.047). Severe submucosal fibrosis was found in five of the eight cases (62.5 %, P = 0.017). Poor differentiation was seen at the deepest invasive portion in six cases (75.0 %), and two of six cases had an invasion depth <2,000 μm. Of 39 EUS cases, 36 not showing deep invasion close to the muscularis propria were completely resected by ESD.

CONCLUSIONS

Submucosal fibrosis and poor differentiation at the deepest invasive portion may be risk factors for VM+ in colorectal ESD for tumors with submucosal deep invasion. ME plus EUS is more likely to help determine whether ESD is indicated as complete total excisional biopsy for SMca.

Which treatment for large rectal adenoma? Preoperative assessment and therapeutic strategy

In the present review the authors discuss the standard ways of preoperative work-up for a suspected large rectal non-invasive lesion, comparing East and West different attitudes both in staging and treatment. Looking at the literature and analyzing recent personal data, neither pit-pattern classification, nor EUS, nor biopsy histology, nor lifting sign verification, nor digital examination allow a specificity of more than three fourth of such cases. The authors disquisition about which optimal treatment excludes a role for EMR for the impossibility to obtain a single en-bloc specimen, minimum requirement for a correct lateral and vertical margin assessment. For the same reason ESD should be preferred, although a recent meta-analysis of the literature defined that one fourth of patients undergoing ESD for a preoperatively assessed non-invasive large rectal lesion fail to receive an R0 en-bloc resection. This forces about 10% of patients treated by flexible endoscopy to undergo abdominal surgery, which is about fourfold higher than TEM. While awaiting further implementation of modern technologies both to improve staging and to reduce invasiveness, a full-thickness excision of the rectal wall by TEM still represents the standard treatment even for suspected benign diseases.

Real-time histology in colonoscopy

Gastrointestinal endoscopy had major technological improvements and novel technologies in recent years. High-definition endoscopy has permitted an increasingly detailed view of the mucosa during colonoscopy. Filter techniques that enhance analysis of vessel and surface structures. Autofluorescence imaging relies on functional imaging of tissue alterations. Endocytoscopy is an ultrahigh-contact microscopy procedure for cellular analysis of the epithelium. Endomicroscopy is an adaption of laser scanning microscopy for real-time intravital surface and subsurface microscopy during endoscopy. With these technologies, endoscopy has moved from prediction of histology based on morphologic patterns toward visualization of cellular and subcellular details, providing real-time histology.

Colorectal neoplasia in long-standing ulcerative colitis - a prospective study from a low-prevalence area

AIM

Despite increasing recognition of ulcerative colitis (UC) in Asia in recent decades, reports on the occurrence of colorectal neoplasia (CRN) in UC are scarce and surveillance for this complication is not routinely practised in this region. We aimed to assess the outcome of a newly initiated pilot screening programme for screening CRN among UC patients in India.

METHOD

In this prospective study from an academic hospital setting, patients with UC at high risk of CRN were offered screening by magnifying chromocolonoscopy and the frequency of neoplastic lesions was assessed.

RESULTS

Twenty-nine (70.7%) of 41 eligible patients [a median age of 46 (interquartile range 36-54.5) years; 17 (58.6%) men] enrolled for surveillance; 41 colonoscopies were undertaken over 42 months. The median disease duration was 10 (interquartile range 7.5-14.5) years. Sixteen (55.1%) had extensive colitis. On initial screening, low-grade dysplasia (LGD) was seen in five (17.2%) and high-grade dysplasia (HGD) in three (10.3%). Of these three, one accepted proctocolectomy immediately, one underwent surgery for adenocarcinoma and one refused surgery. Twelve follow-up colonoscopies in nine patients revealed three new LGD.

CONCLUSIONS

High-grade dysplasia and subsequent adenocarcinoma can be detected with careful follow-up in Indian patients with long-standing UC but acceptance of surveillance and subsequent therapy are suboptimal. We found evidence that screening and surveillance programmes are useful for detecting neoplasias in UC, and need to be customized for this region.

Endoscopy and polyps-diagnostic and therapeutic advances in management

Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options.

Topical submucosal chromoendoscopy defines the level of resection in colonic EMR and may improve procedural safety (with video)

BACKGROUND

Blue dyes such as indigo carmine have become a frequent component of the submucosal injectate for EMR. Confirmation of the correct resection plane and assessment of the resection defect are facilitated by the selective staining of the submucosal layer. Nonstained areas are more difficult to evaluate and may contain inadvertent muscularis propria (MP) injury. The use of topical submucosal chromoendoscopy (TSC) may allow rapid and accurate assessment of these unstained areas and visual recognition of MP injury.

OBJECTIVE

To evaluate the utility of a novel technique in the assessment of nonstained areas within the post-EMR defect.

DESIGN

Single-center prospective cohort study.

SETTING

Academic, tertiary care referral center.

PATIENTS

A total of 143 patients undergoing wide-field colonic EMR for sessile lesions 20 mm or larger.

INTERVENTIONS

A standard inject-and-resect EMR technique was applied with indigo carmine blue dye in the injectate. Defects with areas of nonstaining were recorded and examined, and then irrigated with the submucosal injectate by using the blunt tip of the injection catheter.

MAIN OUTCOME MEASUREMENTS

Detection of additional cases of MP injury by using TSC.

RESULTS

A total of 147 EMRs were performed. Focal areas of defect nonstaining were seen in 25 of cases (17%), with no MP injury identified on initial examination. After TSC, 2 additional cases of MP injury were identified, and these were successfully managed endoscopically. Intraprocedural recognition of deep resection increased from 4 cases (2.8%) to 6 cases (4.1%), thereby avoiding potential delayed perforation in 2 patients.

LIMITATIONS

Single-center, nonrandomized study.

CONCLUSIONS

TSC is simple and effective and rapidly confirms the plane of resection and may improve detection of intraprocedural perforation.

Characteristic magnifying narrow-band imaging features of colorectal tumors in each growth type

PURPOSE

We investigated the surface characteristics and vascular patterns of colorectal tumors according to growth type by means of magnifying narrow-band imaging (NBI).

METHODS

Four hundred ninety-seven colorectal tumors larger than 10 mm (204 tubular adenomas [TAs], 199 frankly invasive intramucosal carcinomas to shallow invasive submucosal [M/SM-s] carcinomas, and 94 deeply invasive submucosal [SM-d] carcinomas) were analyzed. These colorectal tumors were classified according to growth type as follows: polypoid type, n = 224; laterally spreading tumor-granular (LST-G) type, n = 133; and LST-non-granular (LST-NG) type, n = 140. Surface and vascular patterns were evaluated in relation to histology and growth type.

RESULTS

The absent and irregular surface patterns were observed in approximately 40 % of the SM-d carcinomas of the polypoid and LST-G type. The unclear surface pattern was more frequent in tumors of the LST-NG type than in those of other growth types, regardless of histology. Among TAs and M/SM-s carcinomas, the dense vascular pattern was most frequent in polypoid type, the dense and corkscrew vascular patterns were most frequent in the LST-G type, and the honeycomb and avascular and/or fragmentary patterns were most frequent in the LST-NG type. The avascular and/or fragmentary vessel pattern was more frequent in SM-d carcinomas than in TA and M/SM-s carcinomas, regardless of growth type.

CONCLUSIONS

A part of LST-NG was difficult to identify the NBI magnifying surface pattern. Although NBI magnifying findings were almost same in each type lesion in SM-d lesion, those of LST-NG were different from those of LST-G and polypoid type in M/SM-s lesion.

Interobserver agreement among endoscopists on evaluation of polypoid colorectal lesions visualized with the Pentax i-Scan technique

BACKGROUND AND AIMS

Advances in colonoscopy, such as the Pentax i-Scan electronic technique, have the potential to improve the early detection of colorectal cancer. The aim of this multicentre study was to assess the interobserver agreement in the visualization of the surface and margins of colorectal polyps and in distinguishing neoplastic from non-neoplastic polyps.

PATIENTS AND METHODS

Eight expert endoscopists examined 400 mixed previously recorded images of polyps taken with different Pentax i-Scan settings in order to give an evaluation of the surface of the polyp and regular colonic mucosa, the pit-pattern and the nature of the lesion.

RESULTS

A total of 400 mixed images of polyps with a diameter >5mm and <10mm were stored for analysis. Overall, there was a Kf agreement of 0.370 (p<0.001) and 0.306 (p<0.001) regarding pit-pattern and margins, respectively. The Kf agreement for the difference between neoplastic and non-neoplastic lesions was of 0.446 (p<0.001).

CONCLUSIONS

We observed good interobserver agreement in the evaluation of neoplastic and non-neoplastic lesions and poor agreement in the evaluation of pit-pattern and margins. Adequate training is required in order to interpret images acquired with the i-Scan technique.