Staging of colonic neoplasms by colonoscopic miniprobe ultrasonography

Lymph node metastasis risk factors in T2 colorectal cancer

OBJECTIVES

This study evaluates risk factors for lymph node metastasis (LNM) in T2 colorectal cancer to refine patient selection for endoscopic resection.

METHODS

We reviewed records from consecutive patients who had undergone curative surgical resection of T2 colorectal cancer at our institution in Japan between April 2001 and December 2021. Data on conventional clinicopathologic variables were retrieved from the pathology reports at the time of surgery. The clinicopathological features included patient age, sex, tumor diameter, morphology, tumor location, lymphatic invasion, vascular invasion, tumor differentiation, carcinoembryonic antigen and carbohydrate antigen 19-9 levels, number of lymph node dissections, presence of adenoma component, and LNM.

RESULTS

Among the patients (338 men, 320 women), 170 (25.8%) exhibited LNM. Multivariate logistic regression identified three independent risk factors for LNM: lymphatic invasion (odds ratio [OR], 32.6; 95% confidence interval [CI], 17.3-61.4; p < 0.0001), female sex (OR, 1.70; 95% CI, 1.10-2.62; p = 0.02), and elevated carcinoembryonic antigen levels (OR, 2.56; 95% CI, 1.10-5.96; p = 0.03).

CONCLUSIONS

Lymphatic invasion, female sex, and high carcinoembryonic antigen levels significantly increase the risk of LNM in T2 colorectal cancer.

Factors influencing interruption of colorectal endoscopic submucosal dissection

BACKGROUND AND AIMS

Although colorectal endoscopic submucosal dissection (ESD) has become a standardized procedure worldwide, the difficulty of the procedure is well known. However, there have been no studies assessing the causes of treatment interruption. The present study aimed to evaluate the factors involved in the interruption of colorectal ESD.

METHODS

We retrospectively analyzed 1116 consecutive superficial colorectal neoplasms of 1012 patients who were treated with ESD between August 2008 and September 2018. The clinicopathological characteristics and treatment outcomes were analyzed.

RESULTS

Interrupted ESD was reported in 14 lesions (1.3%) of the total study population. Univariate analysis of clinical characteristics indicated that age, 0-I macroscopic-type tumor, and tumor location on the left side colon were risk factors for interruption. Multivariate analysis revealed that 0-I macroscopic-type tumor was the sole preoperative independent risk factor for interruption. Univariate analysis revealed that the presence of muscle-retracting sign (MRS), deep submucosal tumor invasion, and intermediate invasive growth pattern represented the etiology of interruption. Multivariate analysis indicated that MRS can be a sole key sign for the interruption. Additionally, the resectability and curability of 0-I type tumors were significantly inferior to those of predominantly lateral spreading tumors. Observations of 0-I macroscopic-type tumors, MRS, and submucosal deep invasion were significantly more frequent in interrupted cases. Conventional endoscopic images without magnification endoscopy were more associated with interruption than irregular surfaces or Vi pit patterns in cases with 0-I type tumors.

CONCLUSION

ESD of 0-I type tumors is highly disruptive, and undiagnosable submucosal infiltration can reduce the curability.

Colon carcinoma staging by endoscopic ultrasonography miniprobes

Background and Objectives:

Due to the increasing use of endoscopic techniques for colon cancer resection, pretreatment locoregional staging may gain critical interest. The use of endoscopic ultrasonography (EUS) miniprobes in this context has been seldom reported. Our aim was to determine the accuracy of EUS miniprobes for colon cancer staging.

Materials and Methods:

Forty patients with colon cancer (2 in the cecum, 9 in the ascending colon, 5 in the transverse colon, 5 in the descending colon, and 19 in the sigmoid colon) were submitted to staging using 12 MHz EUS miniprobes. EUS and the anatomopathological results were compared with regard to the T and N stages. It was assessed if the location, longitudinal extension, or circumferential extension of the tumor had any influence on the accuracy in EUS staging.

Results:

Tumor staging was feasible in 39 (98%) patients except in one case with a stenosing tumor (out of 6). Globally, T stage was accurately determined in 88% of the cases. In the assessment of the presence or absence of lymph node metastasis, miniprobes presented an accuracy of 82% with a sensitivity of 67%. These results were neither affected by the location nor by the longitudinal or circumferential extension of the tumor.

Conclusions:

EUS miniprobes may play an important role in assessing T and N stages in colon cancer and may represent an incentive to the research of new therapeutic areas for this disease.

Management of colorectal T1 carcinoma treated by endoscopic resection

As a result of recent advances in endoscopic therapeutic technology, the number of endoscopic resections carried out in the treatment of early colorectal carcinomas with little risk of lymph node metastasis has increased. There are no reports of lymph node metastasis in intramucosal (Tis) carcinomas, whereas lymph node metastasis occurs in 6.8-17.8% of submucosal (T1) carcinomas. Three clinical guidelines have been published in Japan and the management strategy for early colorectal tumors has been demonstrated. According to the 2014 Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines for the Treatment of Colorectal Cancer, additional surgery should be done in cases of endoscopically resected T1 carcinoma with a histologically diagnosed positive vertical margin. Additional surgery may also be considered when one of the following histological findings is detected: (i) SM invasion depth ≥1000 µm; (ii) histological type por., sig., or muc.; (iii) grade 2-3 tumor budding; and (iv) positive vascular permeation. A resected lesion that is histologically diagnosed as a T1 carcinoma without any of the above-mentioned findings can be followed up without additional surgery. As for the prognosis of endoscopically resected T1 carcinomas, the relapse ratio of approximately 3.4% (44/1312) is relatively low. However, relapse is associated with a poor prognosis, with 72 cancer-related deaths reported out of 134 relapsed cases (54%). A more detailed stratification of the lymph node metastasis risk after endoscopic resection for T1 carcinomas and the prognosis of relapsed cases will be elucidated through prospective studies. Thereafter, the appropriate indications and safe and secure endoscopic resection for T1 carcinomas will be established.

Diagnostic Value of Endorectal Ultrasound in Preoperative Assessment of Lymph Node Involvement in Colorectal Cancer: a Meta-analysis

BACKGROUND

Nodal invasion by colorectal cancer is a critical determinant in estimating patient survival and in choosing appropriate preoperative treatment. The present meta-analysis was designed to evaluate the diagnostic value of endorectal ultrasound (EUS) in preoperative assessment of lymph node involvement in colorectal cancer.

MATERIALS AND METHODS

We systematically searched PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases for relevant studies published on or before December 10th, 2014. The sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were assessed to estimate the diagnostic value of EUS. Subgroup analysis and meta-regression were performed to explore heterogeneity across studies.

RESULTS

Thirty-three studies covering 3,016 subjects were included. The pooled sensitivity and specificity were 0.69 (95%CI: 0.63-0.75) and 0.77 (95%CI: 0.73-0.82), respectively. The positive and negative likelihood ratios were 3.09 (95%CI: 2.52-3.78) and 0.39 (95%CI: 0.32-0.48), respectively. The DOR was 7.84 (95%CI: 5.56-11.08), and AUC was 0.80 (95%CI: 0.77-0.84).

CONCLUSIONS

This meta-analysis indicated that EUS has moderate diagnostic value in preoperative assessment of lymph node involvement in colorectal cancer. Further refinements in technology and diagnostic criteria are necessary to improve the diagnostic accuracy of EUS.

Endoscopic ultrasound for staging of colonic cancer proximal to the rectum: A systematic review and meta-analysis

Background and Objectives:

Treatment of colonic cancer patients is highly dependent on the depth of tumor invasion (T-stage) as well as the extension of lymph node involvement (N-stage). We aimed to systematically review the accuracy of endoscopic ultrasound (EUS) for staging of colonic cancer proximal to the rectum.

Patients and Methods:

Men and women with colonic adenocarcinomas were included in the study. EUS staging was compared to histopathology as the gold standard. Outcome measures were T- and N-staging accuracies. Articles were searched in PubMed, Web of Science, The Cochrane Library, and EMBASE.

Results:

Six studies were identified comparing EUS staging of colonic cancer to histopathology. The pooled-staging sensitivity and specificity were 0.90 and 0.98 for T1 tumors, 0.67 and 0.96 for T2 tumors, and 0.97 and 0.83 for T3/T4 tumors, respectively. Sensitivity and specificity for N + disease were 0.59 and 0.78, respectively.

Conclusions:

EUS is a feasible method for T-staging of cancers of the colon proximal to the rectum. The accuracy of lymph node staging needs to be verified by prospective multicenter studies including larger patient populations.

Incidence and risk factors of delayed postpolypectomy bleeding in patients with chronic liver disease

OBJECTIVE

Hepatologists and colonoscopists often hesitate to perform a colonoscopic polypectomy in patients with chronic liver disease (CLD), especially those with cirrhosis, because of the risk of postpolypectomy bleeding (PPB). We aimed to investigate the incidence and risk factors of delayed PPB after a colonoscopic polypectomy in patients with CLD.

MATERIALS AND METHODS

In total, 152 patients with CLD who underwent colonoscopic polypectomy from December 2005 to December 2012 were retrospectively reviewed.

RESULTS

Cirrhosis was identified in 80 (52.6%) patients. During the study period, 442 polyps were removed and delayed PPB developed in 14 (9.2%) patients. The incidence of delayed PPB was significantly higher in patients with cirrhosis than in those without the disease (13.8% [n = 11] vs. 4.2% [n = 3], p = 0.041). The polyp size (odds ratio, 1.087; 95% confidence interval, 1.009-1.172) and cirrhosis (odds ratio, 8.535; 95% confidence interval, 2.417-30.140) were independent risk factors for delayed PPB. In patients with cirrhosis, the optimal cut-off size to identify high-risk polyps for delayed PPB was 10 mm (area under the receiver operating characteristics curve, 0.737; sensitivity, 52%; specificity, 88%).

CONCLUSION

Caution is needed when colonoscopic polypectomy is planned in patients with CLD who have larger polyps and cirrhosis.

Clinical significance of the muscle-retracting sign during colorectal endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

During colorectal endoscopic submucosal dissection (ESD), the feature of a muscle layer being pulled toward a neoplastic tumor is sometimes detected. We call this feature the muscle-retracting sign (MR sign). The aim of this study was to evaluate whether the MR sign is associated with particular types of neoplastic lesions and whether it has any clinical significance for ESD sessions.

PATIENTS AND METHODS

A total of 329 patients underwent ESD for 357 colorectal neoplasms. The frequency of positivity for the MR sign was evaluated in different morphologic and histopathologic types of neoplasm. The success rate of complete resection and the incidence of complications were also evaluated according to whether lesions were positive or negative for the MR sign.

RESULTS

The rates of positivity for the MR sign in the various lesion types were as follows: laterally spreading tumor - granular nodular mixed type (LST-G-M), 9.6 %; laterally spreading tumor - granular homogeneous type (LST-G-H) and laterally spreading tumor - nongranular type (LST-NG), 0 %; sessile type, 41.2 %. The resection rate was 100 % (329 /329) in lesions negative for the MR sign; however, it was 64.3 % (18 /28) in lesions positive for the MR sign, which was significantly lower (P < 0.001).

CONCLUSIONS

The MR sign was present only in some protruding lesions, and more importantly, it was associated with a high risk of incomplete tumor removal by ESD. Our data indicate that lesions positive for the MR sign lesions should be dissected with great caution; alternatively, based on the features of the individual case, a switch to surgery should be considered for the benefit of the patient.

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

METHODS: A retrospective study with prospectively entered database. From March 2012 to February 2013, a total of 21 patients (11 men) (mean age 64.2 years) with colon cancer beyond the rectum were recruited. The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum. Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.

RESULTS: The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1 min, respectively. The echoendoscope passed through the lesions in 13 patients (61.9%) and reached the cecum in 10 of 13 patients (76.9%). No adverse events were found. The lesions were located in the cecum (n = 2), ascending colon (n = 1), transverse colon (n = 2), descending colon (n = 2), and sigmoid colon (n = 14). The accuracy rate for T1 (n = 3), T2 (n = 4), T3 (n = 13) and T4 (n = 1) were 100%, 60.0%, 84.6% and 100%, respectively. The overall accuracy rates for the T and N staging of colon cancer were 81.0% and 52.4%, respectively. The accuracy rates among traversable lesions (n = 13) and obstructive lesions (n = 8) were 61.5% and 100%, respectively. Endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0% and 68.4%, respectively.

CONCLUSION: The echoendoscope is a feasible staging tool for colon cancer beyond rectum. However, accuracy of the echoendoscope needs to be verified by larger systematic studies.

Mini-probe ultrasonography for the staging of colon cancer: a systematic review and meta-analysis

AIM

With an increasing array of treatment modalities available for colon cancer, it is increasingly important to stage tumours accurately to allocate the appropriate management. This study evaluated the accuracy of mini-probe endoscopic ultrasound (EUS) in assigning clinical stage to colon cancer.

METHOD

An electronic search was performed in January 2013 using the Embase, MEDLINE and Cochrane databases. This was supplemented by a hand search of published abstracts from scientific meetings. Trials evaluating the accuracy of the mini-probe EUS compared with histopathological grade in determining the clinical stage of colon cancer were included in this pooled analysis. The main outcome measures included accuracy, sensitivity and specificity for T and N staging.

RESULTS

Ten studies were identified which compared the mini-probe EUS staging of 642 colon or rectal cancers with the histopathological specimen. The pooled sensitivity and specificity for staging were 0.91 and 0.98 for T1 tumours, 0.78 and 0.94 for T2 tumours, 0.97 and 0.90 for T3/T4 tumours and 0.63 and 0.82 for nodal staging. Eight per cent of T1/T2 tumours were upstaged to T3/T4 tumours and 5% of T3/T4 tumours were downstaged.

CONCLUSION

Mini-probe EUS is highly effective for assigning clinical stage in colon cancer and in identifying patients who may be suitable for nonsurgical treatment including neoadjuvant chemotherapy or endoscopic resection.

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.

Miniprobe endoscopic ultrasonography has limitations in determining the T stage in early colorectal cancer

Background/Aims

Mini-probe endoscopic ultrasonography (mEUS) is a useful diagnostic tool for accurate assessment of tumor invasion. The aim of this study was to estimate the accuracy of mEUS in patients with early colorectal cancer (ECC).

Methods

Ninety lesions of ECC underwent mEUS for pre-treatment staging. We divided the lesions into either the mucosal group or the submucosal group according to the mEUS findings. The histological results of the specimens were compared with the mEUS findings.

Results

The overall accuracy for assessing the depth of tumor invasion (T stage) was 84.4% (76/90). The accuracy of mEUS was significantly lower for submucosal lesions compared to mucosal lesions (p=0.003) and it was lower for large tumors (≥2 cm) (p=0.034). The odds ratios of large tumors and submucosal tumors affecting the accuracy of T staging were 3.46 (95% confidence interval [CI], 1.05 to 11.39) and 6.25 (95% CI, 1.85 to 25.14), respectively. When submucosal tumors were combined with large size, the odds ratio was 14.67 (95% CI, 1.46 to 146.96).

Conclusions

The overall accuracy of T stage determination with mEUS was considerably high in patients with ECC; however, the accuracy decreased when tumor size was >2 cm or the tumor had invaded the submucosal layer.

In vivo endoluminal ultrasound biomicroscopic imaging in a mouse model of colorectal cancer

RATIONALE AND OBJECTIVES

The gold-standard tool for colorectal cancer detection is colonoscopy, but it provides only mucosal surface visualization. Ultrasound biomicroscopy allows a clear delineation of the epithelium and adjacent colonic layers. The aim of this study was to design a system to generate endoluminal ultrasound biomicroscopic images of the mouse colon, in vivo, in an animal model of inflammation-associated colon cancer.

MATERIALS AND METHODS

Thirteen mice (Mus musculus) were used. A 40-MHz miniprobe catheter was inserted into the accessory channel of a pediatric flexible bronchofiberscope. Control mice (n = 3) and mice treated with azoxymethane and dextran sulfate sodium (n = 10) were subjected to simultaneous endoluminal ultrasound biomicroscopy and white-light colonoscopy. The diagnosis obtained with endoluminal ultrasound biomicroscopy and colonoscopy was compared and confirmed by postmortem histopathology.

RESULTS

Endoluminal ultrasound biomicroscopic images showed all layers of the normal colon and revealed lesions such as lymphoid hyperplasias and colon tumors. Additionally, endoluminal ultrasound biomicroscopy was able to detect two cases of mucosa layer thickening, confirmed by histology. Compared to histologic results, the sensitivities of endoluminal ultrasound biomicroscopy and colonoscopy were 0.95 and 0.83, respectively, and both methods achieved specificities of 1.0.

CONCLUSIONS

Endoluminal ultrasound biomicroscopy can be used, in addition to colonoscopy, as a diagnostic method for colonic lesions. Moreover, experimental endoluminal ultrasound biomicroscopy in mouse models is feasible and might be used to further develop research on the differentiation between benign and malignant colonic diseases.

Snaring large serrated polyps

BACKGROUND

Serrated polyps of the large bowel are potentially premalignant, difficult to see, but important to remove. Few studies describe the technique or outcomes of serrated polypectomy. We sought to present outcomes of a series of polypectomies of large serrated polyps in comparison to a series of endoscopic resections of large adenomas.

METHODS

This retrospective, comparative, single endoscopist study was performed in an outpatient colonoscopy department of a tertiary referral medical center. Patients had outpatient colonoscopy where a large (≥2 cm) serrated polyp or adenoma was removed. Outcomes were completeness of excision and complications of polypectomy. A database of endoscopic polypectomies was reviewed. Polypectomy of large serrated polyps was compared with polypectomy of large adenomas.

RESULTS

There were 132 large serrated polyps in 112 patients and 563 adenomas in 428 patients. More serrated polyps were right sided (120 of 130, 92.3 %, vs. 379 of 563, 67 %) (p < 0.0001). The serrated polyps were smaller than the adenomas (mean 25.5 ± 7.9 mm standard deviation) versus 36.8 ± 16.9 mm standard deviation (p < 0.001). There were four complications of serrated polypectomy in four patients (4 % of polyps, 5 % of patients): three postpolypectomy bleeds and one postpolypectomy syndrome. There were 33 complications of adenoma removal (31 postpolypectomy bleeding and two postpolypectomy syndrome) (6.9 % of polyps, p = 0.376, 8.4 % of patients, p = 0.371). On follow-up, 36 of 51 patients (71 %) with serrated polyps had metachronous lesions compared to 133 of 298 patients (45 %) with adenomas (p < 0.0001). There were fewer residual polyps in the serrated group (4 of 47 vs. 64 of 298, p = 0.001).

CONCLUSIONS

Removal of large serrated colorectal polyps is no more complicated than polypectomy of similarly sized adenomas. However, large serrated polyps have a higher rate of metachronous polyps than similarly sized adenomas and surveillance should be adapted to reflect these findings.

Early duodenal adenocarcinoma resembling a submucosal tumor cured with endoscopic resection: a case report

INTRODUCTION

Primary adenocarcinomas resembling submucosal tumors are rare in the gastrointestinal tract. Almost all the submucosal tumor-like adenocarcinomas previously reported invaded the submucosa or deeper. Therefore, submucosal tumor-like lesions are usually treated by surgical resection, and those that arise in the duodenum have been treated by pancreaticoduodenectomy.

CASE PRESENTATION

A 65-year-old Japanese man was diagnosed with a submucosal tumor-like adenocarcinoma in his duodenum. We considered it possible that the tumor invasion was limited to the mucosal or submucosal layers and could be removed by endoscopic resection. Tumor histopathology revealed a well-differentiated adenocarcinoma confined to the muscularis mucosae with no lymphovascular invasion. Complete resection of the carcinoma was achieved and there has been no recurrence three years after endoscopic resection.

CONCLUSIONS

We suggest that submucosal tumor-like adenocarcinomas arising in nonampullary duodenal sites should be diagnosed carefully with a view to possible endoscopic resection.

Colonoscopic high frequency mini-probe ultrasound is more accurate than conventional computed tomography in the local staging of colonic cancer

AIM

Colonoscopic high frequency mini-probe ultrasound was compared prospectively with CT in the local staging of colonic cancer.

METHOD

Consecutive patients undergoing surgical resection for colonic cancer were recruited. Preoperative 64-slice CT staging with multiplanar reconstruction was compared with colonoscopic high frequency mini-probe ultrasound using 12 MHz and 20 MHz probes. The three methods of staging (CT, 12 MHz ultrasound and 20 MHz ultrasound) were compared with the histological stage of the resected specimen. This was done using weighted kappa coefficients where weights of 0.7-0.8 were given to penalize disagreements of one level in either direction and weights of zero were given to penalize disagreements of more than one level in any direction.

RESULTS

In total, 38 patients with colonic cancer were included. They were located in the sigmoid (n = 20), descending (n = 5), ascending (n = 2) and transverse colon (n = 1) and in the caecum (n = 7) and splenic (n = 2) and hepatic (n = 1) flexure. Histopathological assessment revealed seven pT1, four pT2, 25 pT3 and two pT4 cancers. In relation to the pathology the weighted kappa coefficients were 0.36 (SE = 0.14), 0.81 (SE = 0.16) and 0.81 (SE = 0.17) for CT, ultrasound 12 MHz and ultrasound 20 MHz. Histopathologically 15 (39.5%) patients were lymph node positive. The sensitivity, specificity and kappa coefficient for detection of nodal disease for CT were 80%, 47.8% and 0.25 (SE = 0.14) compared with 80%, 82.5% and 0.62 for 12 MHz ultrasound (SD = 0.14) and 23%, 90.5% and 0.15 (SD = 0.13) for 20 MHz ultrasound.

CONCLUSION

Colonoscopic ultrasound is significantly more accurate than CT for T staging of colonic cancers. With respect to nodal status, 12 MHz ultrasound offers superior accuracy to CT or 20 MHz ultrasound.

Features of in vitro ultrasound biomicroscopic imaging and colonoscopy for detection of colon tumor in mice

The present work tested the capability of ultrasound biomicroscopy (UBM), at 45 MHz, to provide cross-sectional images with appropriate resolution and contrast to detect tumors and determine their penetration depths on the colon of mice, Mus musculus (Linnaeus 1758), treated with carcinogen for colon tumor induction. B-mode images were obtained, in vitro, from each animal (13 treated and 4 untreated) colon opened longitudinally and immersed in saline solution at room temperature. Prior to UBM inspection, all animals were also examined by colonoscopy. The layers of normal colon identified by UBM are: mucosa (hyperechoic), muscularis mucosae (hypoechoic), submucosa (hyperechoic) and muscularis externa (hypoechoic). UBM images of colon lesions presented structures corresponding to tumors (hyperechoic), lymphoid hyperplasia (hypoechoic) and polypoid tumors (hyperechoic). Additionally, tumoral lesion invasion through the colon was also identified. When compared with histopathologic analysis, all colon lesions detected by UBM were confirmed, while colonoscopic findings had two false negatives.

A meta-analysis and systematic review of prophylactic endoscopic treatments for postpolypectomy bleeding

PURPOSE

The aim of this meta-analysis and systematic review was to determine whether bleeding prophylaxis benefits patients after colonoscopic polypectomy.

METHODS

A systematic review of the literature was performed to find prospective randomized controlled trials of postpolypectomy hemorrhage prophylaxis. Studies were selected according to specific criteria and analyzed to generate pooled data.

RESULTS

Eight studies encompassing 2,595 polyps met the criteria for the meta-analysis. The rate of early bleeding was significantly decreased relative to the control when a single prophylactic technique was used [2.58% vs. 8.15%, OR = 0.34 (95% CI, 0.20-0.58), P < 0.0001]. The use of multiple prophylactic techniques resulted in a lower early postpolypectomy hemorrhage rate compared with the use of a single prophylactic technique [0% vs. 8.41%, OR = 0.12 (95% CI, 0.03-0.47), P = 0.002]. The late bleeding rate did not differ significantly between the monotherapy and control groups [0.61% vs. 1.39%, OR = 0.37 (95% CI, 0.11-1.28), P = 0.12], and the use of combined preventative techniques did not significantly decrease the late postpolypectomy bleeding (PPB) rate compared with use of a single prophylactic method [1.43% vs. 2.05%, OR = 0.70 (95% CI, 0.32-1.55), P = 0.38].

CONCLUSION

Prophylactic endoscopic treatments are effective at reducing early PPB after colonoscopic polypectomy. However, patients with late PPB may not benefit from bleeding prophylaxis.

Diagnostic precision of CT in local staging of colon cancers: a meta-analysis

AIM

To determine the accuracy of computed tomography (CT) in detecting disease with invasion beyond the muscularis propria (MP) and malignant lymph nodes.

MATERIALS AND METHODS

A literature search of Ovid, Embase, the Cochrane database, and Medline using Pubmed, Google Scholar and Vivisimo search engines was performed to identify studies reporting on the accuracy of CT to predict the staging of colonic tumours. Publication bias was demonstrated by Funnel plots. The sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated using a bivariate random effects model and hierarchical summary operating curves (HSROC) were generated.

RESULTS

Nineteen studies fulfilled all the necessary inclusion criteria. The pooled sensitivity, specificity, DOR for detection of tumour invasion were 86% (95% CI: 78-92%); 78% (95% CI: 71-84%); 22.4 (95% CI: 11.9-42.4). Similarly, the values for nodal detection were 70% (95% CI: 63-73%); 78% (95% CI: 73-82%); 8.1(95% CI: 4.7-14.1). In the subgroup analysis, the best results were obtained in studies utilizing multidetector CT (MDCT).

CONCLUSION

Preoperative staging CT accurately distinguishes between tumours confined to the bowel wall and those invading beyond the MP; however, it is significantly poorer at identifying nodal status. MDCT provides the best results.

Endoclip-assisted resection of large pedunculated colorectal polyps: technical aspects and outcome

BACKGROUND

The most common complication of polypectomy is hemorrhage, and various techniques have been used to prevent this complication.

AIM

This study evaluates the outcomes of endoclip-assisted polypectomy in patients with large pedunculated colorectal polyps, in comparison with a historical control group of patients treated with endoloop-assisted polypectomy.

METHODS

Between January and December 2007, 32 patients with 32 large pedunculated polyps (>or=15 mm) were treated with endoclip-assisted polypectomy (group A). Between January and December 2006, 35 patients with 35 large pedunculated polyps were treated; 33 with endoloop-assisted polypectomy (control, group B) and two cases with endoclips and needle knife, which were included in group A for the analysis.

RESULTS

The mean (+/- standard deviation [SD]) size of polyp head was 26.8 +/- 8.1 mm (range 15-50) in group A and 22.3 +/- 4.1 mm (range 15-30) in group B (P = 0.004). In group A, six polyps had a mean (+/-SD) head size of 40.8 +/- 5.8 mm (range 35-50) and were resected with clips and needle knife. In group A, bleeding occurred in two cases (5.9%), which were associated with the presence of cancer at histology (P = 0.006) and were managed by applying new clips. No bleeding occurred in patients of group B and no perforation and post-polypectomy syndrome occurred in either group. There were three (8.8%) cancerized adenomas in group A and one (3%) in group B. Clip application was possible in all patients, while in two cases, loop placement was impossible.

CONCLUSIONS

In our experience, endoclip-assisted resection is a safe alternative to endoloop for the resection of large pedunculated colorectal polyps when endoloop placement is difficult or impossible.

The concurrence of histologically positive resection margins and sessile morphology is an important risk factor for lymph node metastasis after complete endoscopic removal of malignant colorectal polyps

INTRODUCTION

The optimal procedure to be followed after colonoscopic polypectomy of malignant colorectal polyps with nontumour-free resection margins at histology is a matter of controversy. While some authors recommend merely local or segmental follow-up resection, others favour an oncological resection.

PATIENTS AND METHODS

One hundred five patients, each with a single malignant polyp, were investigated. Patients with a macroscopically evident malignant polyp and those in whom the endoscopist reported incomplete polypectomy were excluded from the study.

RESULTS

Postpolypectomy morbidity was 4%, and postoperative was 14%. In only 39 cases were the resection margins adjudged to be tumour-free. Histology following subsequent surgery or the follow-up examinations revealed a local recurrence or residual carcinoma at the polypectomy site in only three (2.8%) cases and lymph node metastasis in eight (7.6%) cases. Five patients had remnant adenoma at the polypectomy site. Of the high-risk factors, histological incomplete removal (n = 66, p = 0.04, odds ratio (OR) 10.2) and lymph vessel infiltration (n = 7, p = 0.02, OR 9.2) revealed a significant correlation with lymph node metastasis, but not with remnant tumour. In the case of sessile polyp, the assessment of histological incomplete removal was highly significantly correlated with lymph node metastasis (n = 55, p = 0.007, OR 18.1).

CONCLUSIONS

Polypectomy artefacts appear to be responsible for the discrepancy between histology and the tumour remnants actually present. On the other hand, histologically incompletely removed sessile malignant polyps represent an appreciably higher risk for lymph node metastasis. Such cases should, therefore, be submitted to further oncological resection.

Localized resection for colon cancer

Localized resection of early stage colon cancer is increasingly technically feasible by truly minimally invasive means. Such techniques as endoscopic submucosal dissection (ESD) and Natural Orifice Transluminal Endoscopic Surgery (N.O.T.E.S.) now raise the prospect of focused intraluminal and transmural resection of small primary tumors without abdominal wall transgression. The potential clinical benefit that patients may accrue from targeted dissection as definitive treatment in place of radical operation is not yet definitively proven but may be considerable at least in the short-term. However, oncological propriety and outcomes must be maintained. In particular methods by which regional nodal staging can be assured if standard operation is avoided need still to be established. Sentinel node mapping is one such putative means of doing so that deserves serious consideration from this perspective as it performs a similar function for breast cancer and melanoma and because there is already considerable evidence to suggest the technique in colonic neoplasia may be at its most accurate in germinal disease. In addition, it may already be employed by laparoscopy while solely transluminal means of its deployment are advancing. While the confluence of operative technologies and techniques now coming on-stream has the potential to precipitate a dramatic shift in the paradigm for the management of early stage colonic neoplasia, considerable confirmatory study is required to ensure that oncology propriety and treatment efficacy is maintained so that patient benefit may be maximized.

Evaluation of subepithelial abnormalities of the appendix by endoscopic ultrasound

Background. The use of through-the-scope (TTS) miniprobe catheter endoscopic ultrasound is a valuable technique for evaluating subepithelial lesions in the proximal colon. Few reports include the evaluation of the appendix by EUS. Objective. To describe endoscopic and endosonographic characteristics of subepithelial lesions of the appendix. Methods. Retrospective case series in a single academic medical center. Adult patients referred for evaluation of subepithelial lesions of the appendix identified by colonoscopy between April 1, 2003 to February 29, 2008. Data were abstracted from an electronic endoscopic database for all patients undergoing miniprobe endoscopic ultrasound examination of the appendix. Medical records were reviewed for patient followup and outcomes. Results. Nine cases were identified. Seven (78%) patients were female. Seven (78%) utilized the 12 MHz miniprobe device and two (22%) used the 20 MHz device. Three mucoceles were described and confirmed by surgical resection. Cases also included one inverted appendix, one gastrointestinal stromal tumor, and one lipoma. In three cases, no abnormality was found. Conclusions. EUS evaluation of the appendix is feasible with standard miniprobe devices and may assist in the selection of patients who may benefit from surgical management.

Endosonographic staging of lower intestinal malignancy

The use of EUS in the assessment of rectal pathology is well established. The accurate staging of lower intestinal tumours predicts prognosis and guides the planning of individual patient treatment. Increased experience and the development of high resolution three-dimensional EUS has lead to the greater accuracy of rectal staging with EUS of rectal tumours now considered the gold standard showing T stage accuracy that ranges from 75% to 95%, with N stage accuracy ranging from 65% to 80%. The use of EUS in the staging of colonic pathology, however, is not so well established though advances in miniprobe EUS has improved the assessment of colonic tumours. EUS is also of benefit in the assessment of anal pathology though here, accurate correlation with histology has not been firmly established.

Role of endoscopic ultrasonography in predicting the response to cyclosporin A in ulcerative colitis refractory to steroids

BACKGROUND AND AIMS

Although cyclosporin A has been reported to be effective in the treatment of severe ulcerative colitis, factors predicting its therapeutic efficacy remain unclear. Technical progress in endoscopic ultrasonography has improved visualisation of the structure of the colon wall. Here, to assess the value of endoscopic ultrasonography in predicting the response to cyclosporin A treatment, we evaluated the therapeutic effect of cyclosporin A by determining the pre- and post-cyclosporin A thickness of the mucosal layer in the rectum using endoscopic ultrasonography with an ultrasonic catheter probe.

PATIENTS AND METHODS

Fifteen ulcerative colitis patients who did not respond to high-doses of corticosteroids were treated with cyclosporin A by continuous intravenous infusion at 4mg/kg/day for 20 days. Before and 20 days after cyclosporin A therapy, clinical disease activity was assessed using clinical activity index scores. Colonoscopy and endoscopic ultrasonography were undertaken before and 20 days after cyclosporin A therapy.

RESULTS

Following treatment with cyclosporin A, nine patients showed a decrease in clinical activity index score by six points or more and were defined as responders, while the other six were defined as non-responders. Endoscopic ultrasonography measurement using an ultrasonic catheter probe showed that thickness of the rectal mucosal layer before cyclosporin A was significantly greater in responders than in non-responders (p<0.05). Further, thickness after cyclosporin A was statistically decreased (p<0.01) in the responders but not in the non-responders.

CONCLUSIONS

The ultrasonic catheter probe may represent a useful means of predicting and evaluating the efficacy of cyclosporin A treatment in severely ill ulcerative colitis patients.

Successful complete cure en-bloc resection of large nonpedunculated colonic polyps by endoscopic submucosal dissection: a meta-analysis and systematic review

BACKGROUND

Endoscopic submucosal dissection (ESD) has emerged as one of the techniques to successfully resect large colonic polyps en bloc. Complete resection prevents the patient from going through transabdominal colonic resection. We sought to evaluate the proportion of successful en-bloc and complete cure en-bloc resection of large colonic polyps by ESD.

METHODS

Studies that use ESD technique to resect large colonic polyps were selected. Successful en-bloc resection was defined as resection of the polyp in one piece. Successful complete cure en-bloc resection was defined as one piece with histologic disease-free-margin polyp resection. Articles were searched in Medline, PubMed, and Cochrane control trial registry. Pooled proportions were calculated by both fixed and random-effects model.

RESULTS

The initial search identified 2,120 reference articles; 389 relevant articles were selected and reviewed. Data were extracted from 14 studies (n = 1,314) that met the inclusion criteria. The mean +/- standard error size of the polyps was 30.65 +/- 2.88 mm. Pooled proportion of en-bloc resection by the random-effects model was 84.91% (95% confidence interval, 77.82-90.82) and complete cure en-bloc resection was 75.39% (95% confidence interval, 66.69-82.21). The fixed-effects model was not used because of the heterogeneity of studies.

CONCLUSIONS

ESD should be considered the best minimally invasive endoscopic technique in the treatment of large (>2 cm) sessile and flat polyps because it allows full pathological evaluation and cure in most patients. ESD offers an important alternative to surgery in the therapy of large sessile and flat polyps.

Endoscopic resection of large pedunculated colonic polyps and risk of postpolypectomy bleeding with adrenaline injection versus endoloop and hemoclip: a prospective, randomized study

BACKGROUND

Postpolypectomy bleeding is a major complication, especially in large pedunculated colonic polyps. Several endoscopic techniques have been evolved for prevention of bleeding episodes. The aim of this study is to evaluate postpolypectomy bleeding rates in large (>2 cm) pedunculated colonic polyps using either adrenaline injection alone or loop and clip application as prophylactic methods.

MATERIALS AND METHODS

Patients with one pedunculated colonic polyps (>2 cm) were included in a double-blind study and studied prospectively. Exclusion criteria were coexistence of other large polyps, antiplatelet, nonsteroidal anti-inflammatory drugs or aspirin. In group A (n = 32), adrenaline (1:10,000) was injected in the base of the stalk followed by conventional polypectomy using mixed coagulation and cutting current. In group B (n = 32), a detachable snare was placed at the base of the stalk followed by conventional polypectomy and clip application in the residual stalk above the snare. We evaluate the efficacy of combined endoscopic methods in early and late postpolypectomy bleeding rate in large pedunculated colonic polyps, severity of bleeding, days of hospitalization, and required transfusions.

RESULTS

Overall, bleeding complications occurred in 5/64 patients (7.81%). In group A (adrenaline injection alone), four patients (12.5%) had a bleeding episode: two (6.25%) occurred during the first 24 h and two (6.25%) between days 7 and 14 from the procedure. In group B only one patient (3.12%) had a late bleeding episode (p = 0.02). Severity of late bleeding in group B patients (one moderate bleeding) versus group A patients (one moderate and one severe bleeding) and need for transfusions (1 versus 5 blood units) were lower (p = 0.02). Hospitalization days did not differ between the two groups, but colonoscopy time was significantly higher in group B versus group A (p = 0.04).

CONCLUSION

Combined endoscopic techniques seem to be more effective in preventing postpolypectomy bleeding in large pedunculated colonic polyps.

Preoperative staging and treatment options in T1 rectal adenocarcinoma

BACKGROUND

Major rectal resection for T1 rectal cancer offers more than 95% cancer specific five-year survival to patients surviving the first 30 days after surgery. A significant further improvement by development of the surgical technique may not be possible. Improvements in the total survival rate have to come from a more differentiated treatment modality, taking patient and procedure related risk factors into account. Subgroups of patients have operative mortality risks of 10% or more. Operative complications and long-term side effects after rectum resection are frequent and often severe.

RESULTS

Local treatment of T1 cancers combined with close follow-up, early salvage surgery or later radical resection of local recurrences or with chemo-radiation may lead to fewer severe complications and comparable, or even better, long-term survival. Accurate preoperative staging and careful selection of patients for local or non-operative treatment are mandatory. As preoperative staging, at present, is not sufficiently accurate, strategies for completion, salvage or rescue surgery is important, and must be accepted by the patient before local treatment for cure is initiated.

RECOMMENDATIONS

It is recommended that polyps with low-risk T1 cancers should be treated with endoscopic snare resection in case of Haggitt's stage 1 or 2. TEM is recommended if resection margins are uncertain after snare resection for Haggitt's stage 3 and 4, and for sessile and flat, low-risk T1 cancers. Average risk patients with high-risk T1 cancers should be offered rectum resection, but old and comorbid patients with high-risk T1 cancers should be treated individually according to objective criteria as age, physical performance as well as patient's preference. All patients treated for cure with local resection or non-surgical methods should be followed closely.

Retrieval of colorectal polyps following snare polypectomy: Experience of the multiple-suction technique in 602 cases

BACKGROUND

Retrieving colorectal polyp after endoscopic snare polypectomy is time consuming and possibly incurs a failure. The aim of the study was to assess the effectiveness of the multiple-suction (M-S) technique for retrieving a variety of polyps.

MATERIALS AND METHODS

Four hundred and nine cases received endoscopic snare polypectomy from January 2003 to January 2007 were reviewed. The resected polyps were retrieved by M-S technique, in which suction regarded as the leading technique, was taken in combination with channel occlusion, trap, snare, and grasping forcep. Time of cecal intubation and of polypectomy, total examination time, shape, size, location, and number of polyp(s) were recorded. Retrieval time and polyp lost rate were also noted.

RESULTS

A total of 602 polyps more than 3 mm in diameter underwent snare polypectomy. There were 96.7% (582/602) of polyps retrieved by the M-S technique. The mean retrieval time was 1.5 +/- 0.6 min. Time of polypectomy, retrieval time, and total examination time were significantly positive correlative with the number of polyps (P < 0.05). In a univariate analysis, longer retrieval time was significantly associated with larger polyps, more distant polyps from the anus, and a greater number of polyps, while higher polyp lost rate was significantly associated with sessile polyp, smaller polyps, and a greater number of polyps. In a multivariate analysis, retrieval time level (< or = 2.0 or >2.0 min) was linked to the number of polyps.

CONCLUSIONS

The M-S technique is proved to be reliable when used in the majority cases of colorectal polyp retrieval. In retrieving too many polyps, the M-S technique is time consuming, and hence, additional methods should be applied to improve its retrieval effectiveness.

Insulated-tip knife endoscopic mucosal resection of large colorectal polyps unsuitable for standard polypectomy

OBJECTIVES

Endoscopic mucosal resection (EMR) has been shown to be safe and effective. En bloc resection is often not achieved using conventional EMR. Insulated-tip knife (It-knife) EMR has been recently proposed for early gastric cancer dissection and removal. This study was conducted to evaluate the safety and efficacy in obtaining en bloc resection with It-knife EMR of large colonic lesions not resectable with standard endoscopic techniques.

METHODS

A total of 29 patients (19 men, 10 women, mean age 67.5 yr, range 44-88) were included in the study. Lesions were considered not suitable for standard polypectomy because of large diameter (>3 cm), morphology, and/or position. Lesions were located in the rectum (N = 11), sigmoid: (N = 10), descending: (N = 4), transverse: (N = 2), and hepatic flexure (N = 2). After saline injection, circumferential incision and dissection of the lesions were attempted with the aim of achieving en bloc resection.

RESULTS

En bloc resection was achieved in only 55.1% of the lesions (16 out of 29 patients). In the remaining cases, resection was completed with a piecemeal technique. The median size of the en bloc resected specimen was 3 x 3.4 cm. Complications occurred in four patients (13.7%). At histopathology, 13 patients had low-grade dysplasia, 15 high-grade dysplasia. One patient had a tumor invading the submucosa and was submitted to surgery.

CONCLUSIONS

It-knife EMR is a promising technique for attempting en bloc resection of large colonic polyps. Adequate training and caution are required because it can be associated with a higher complication rate than with other EMR modalities.

Olympus Lucera high-resolution vascular ectasia mapping in combination with the type V crypt pattern for the invasive depth estimation and nodal disease estimation in Paris type II colorectal cancers: a comparative prospective analysis to 20 MHz ultrasound

INTRODUCTION

Flat and depressed neoplastic lesions of the colorectum [Paris type (PT) 0-II] localized to the superficial submucosal (sm) layer can be managed using endoscopic mucosal resection. Successful endoluminal management can be enhanced using endoscopic or ultrasound tools that help predict the degree of sm invasion. Previous studies addressing invasive depth estimation using high-magnification chromoscopic colonoscopy showed a low specificity for deep sm layer 3 invasion with miniprobe ultrasound demonstrating better nodal and T stage in vivo prediction. High-resolution vascular mapping of lesions can show microvascular superficial changes that may predict sm invasive disease.

AIMS

Vascular mapping in combination with high-magnification chromoscopic colonoscopy (HMCC) may provide an accurate tool for the invasive depth estimation of PT type II neoplastic lesions as compared with high frequency 20/12.5 MHz miniprobe ultrasound.

METHODS

Sixty-eight patients with a known diagnosis of PT II neoplasia were imaged using 3 "back to back" imaging modalities. Phase 1-vascular ectasia mapping; phase 2-HMCC with crypt analysis according to Nagata criteria; phase 3-12.5/20 MHz miniprobe ultrasound. Lesions predicted as T0/1/N0 were resected using endoscopic mucosal resection with the remaining referred for surgery. Each imaging modality was then compared with the resected histopathologic specimen used as the "gold standard."

RESULTS

N=68 lesions (19 sm1/13 sm2/36 sm3). Overall accuracy of Nagata criteria, Nagata criteria combined with vascular mapping, and ultrasound staging was 65%, 78%, and 94%, respectively (P<0.001) when observing the between phase differences. Fifty-two lesions were resected surgically. The prevalence of node positive disease was 16% (8/52) with the remaining 44/52 (84%) being confirmed pN0 at histopathology. The kappa coefficient of agreement between invasive depth estimation (using histopathology as the gold standard), Nagata stage, Nagata stage plus vascular ectasia mapping and ultrasound stage was 0.47, 0.65, and 0.9, respectively. A significant improvement in between phase differences was observed (P=0.001).

CONCLUSIONS

This is the first study to address the in vivo clinical utility of vascular mapping in combination with HMCC for the T and N staging of PT II neoplasia. Combination imaging may provide an adequate clinical tool for both T and N stage assessment in vivo and help stratify those patients at high risk for T2/N1 disease that may benefit from further high-frequency miniprobe ultrasound (HFUS) assessment and possible primary surgical excision. This is important in the clinical context, given the high overall costs of a second HFUS examination, limitation of HFUS resources, and safe selection of patients undergoing primary endoscopic resection versus surgical resection.

A prospective, randomized comparison of adrenaline injection in combination with detachable snare versus adrenaline injection alone in the prevention of postpolypectomy bleeding in large colonic polyps

OBJECTIVES

Our study sought to compare the efficacy of adrenaline injection in combination with detachable snare versus adrenaline injection alone in the prevention of postpolypectomy bleeding in large colonic polyps.

METHODS

At the time of colonoscopy, patients with at least one colonic polyp > or =2 cm were randomized to receive treatment either by the injection of a 1:10.000 solution of adrenaline and the position of a detachable snare followed by a conventional snare polypectomy (group A) or injection of adrenaline followed by a conventional snare polypectomy (group B). A total of 159 consecutive patients were randomly assigned to one of the above groups. Out of them, 84 patients (47 men, 37 women, mean age 61 yr) were assigned to group A and 75 (37 men, 38 women, mean age 64 yr) to group B. Early (<24 h) and late (>24 h-30 days) bleeding complications were assessed.

RESULTS

Overall bleeding complications occurred in 10/159 (6.2%) of the patients. There were two cases of bleeding in group A (2.3%), and eight in group B (10.6%) (P= 0.04). The number of early bleeding episodes was significantly reduced in group A patients (1 case) compared to that of group B (7 cases) (P= 0.02). In contrast, there was no significant difference between group A and B as far as late bleeding is concerned.

CONCLUSIONS

Our data suggest that the use of adrenaline injection in combination with detachable snare may significantly decrease the number of early postpolypectomy bleeding episodes in patients with large colonic polyps.

An update on imaging of colorectal cancer

Screening of asymptomatic average-risk patients for presence of colon cancer and early detection in precursor stages is of great interest to general population. Comprehensive evaluation of symptomatic or high-risk patients represents another important clinical focus. Available techniques for total colon imaging, rectal cancer staging and the role of positron emission tomography are discussed.

Giant adenomas of the rectum: complete resection by transanal endoscopic microsurgery (TEM)

BACKGROUND

Large sessile adenomas of the rectum, with a diameter greater than 5 cm, have a high risk to undergo malignant transformation. Transanal endoscopic microsurgery (TEM) offers an alternative operation method to low-anterior rectum resection in this potentially benign tumor situation.

PATIENTS

We retrospectively investigated patients with giant adenomas of the rectum (>5 cm) who were treated by TEM over the last 10 years. A total of 33 patients met the criteria and were analyzed for postoperative complications, histology, and incidence of occult adenocarcinoma; residual tumor status; and tumor recurrence.

RESULTS

Partial suture-line insufficiency (n=5, 15%) was the major postoperative complication, but could be managed conservatively in four cases. The residual adenoma status was 18% (n=6), especially in patients with tumors sizes more than 30 cm2. In case of adenoma recurrence (n=4, 12%), a conventional transanal excision (Parks) was applicable, as these tumors were mostly located within the suture-line region of the lower rectum. Incidentally, five carcinomas were found in the specimens. In case of advanced tumors (1xpT2, 1xpT3), anterior rectum resection was carried out, whereas for the early tumors (2xpT1 low risk, 1x1 pTis), no further therapy was added. All patients (adenomas and carcinomas, n=33) were without recurrence during follow-up.

CONCLUSION

TEM is an alternative method for the resection of large benign rectal tumors located in the mid- and upper third of the rectum. The main postoperative complication is suture-line insufficiency, which generally heals by conservative treatment.

20-MHz high-frequency endoscopic ultrasound-assisted endoscopic mucosal resection for colorectal submucosal lesions: a prospective analysis

GOALS

To prospectively assess the safety and efficacy of high-frequency ultrasound assisted mini-probe endoscopic mucosal resection for the treatment of colorectal submucosal tumors. Primary endpoints were tumor free vertical/horizontal resection margins and positive histopathologic diagnosis. Outcome data over a 24-month period were assessed.

BACKGROUND

A 20-MHz high-frequency mini-probe ultrasound is an accurate modality for the diagnosis of stage T1m and T1 colorectal lesions. Few studies have addressed the safety and efficacy of this technology as applicable to submucosal lesions of the colorectum.

METHODS

Thirty patients underwent high-frequency mini-probe ultrasound-guided endoscopic mucosal resection of 30 lesions (<20 mm diameter) using the inject and cut technique. Repeat endoscopy and ultrasound was performed at 3, 6, and 12 months post-"index" resection.

RESULTS

A total of 27 lesions (90%) underwent complete resection with negative histologic margin status (median diameter, 8 mm; range, 3-20 mm). No statistical difference (P > 0.1) was observed between submucosal lesion position and histologic resection margin negativity. Three rectal lesions (10%) within the submucosal layer 3 failed to separate from the muscularis and underwent transanal excision of tumor. Bleeding occurred in 1 patient (3%). No recurrence was evident at the resection site in 27 cases (median follow-up, 9 months; range, 4-18 months).

CONCLUSIONS

High-frequency mini-probe ultrasound-guided endoscopic mucosal resection is a safe and effective therapeutic modality for submucosal lesions of the colorectum. The technique offers a single-stage diagnostic and therapeutic technique for selected submucosal lesions and may offer an alternative to surgical resection.

Laser photoablation of colorectal adenomas: a 12-year experience

BACKGROUND

We analyze laser photoablation as an alternative treatment of large sessile polyps in inoperable patients.

METHODS

Ninety-four colorectal polyps (mean diameter 3.09 +/- 2.7 cm, range 1-15 cm) were treated using high-energy lasers (Nd:YAG and diode). Grade of dysplasia was low in 51, high in 35, with focally invasive cancer in eight.

RESULTS

After 405 laser sessions (4.3 per polyp) five procedure-related complications were observed: two strictures, two bleedings, and one perforation. The last needed a surgical resection; the others were successfully treated by endoscopic therapy. Fifty-seven polyps (61%) were completely eradicated and the growth was controlled in all but two (98%). No degeneration was found after 28-month follow-up of treated adenomas with low- or high-grade dysplasia. Outcome of treatment was dependent on the dimension and grade of the dysplasia (p < 0.05), but not on the polyps' position (rectum or colon). Relief of rectal bleeding was obtained in 90%, of mucus discharge in 77%, and of tenesmus in 100% of cases.

CONCLUSIONS

Laser photoablation of colonic adenomas can be considered a valid procedure not only to relieve symptoms, but also to control the risk of degeneration in patients unfit for surgery or when surgical treatment is considered excessively invalidating.

Role of endoscopic miniprobe ultrasonography in diagnosis of submucosal tumor of large intestine

AIM: To evaluate the role of miniprobe ultrasonography under colonoscope in the diagnosis of submucosal tumor of the large intestine, and to determine its imaging characteristics.

METHODS: Thirty-five patients with submucosal tumors of the large intestine underwent miniprobe ultrasonography under colonoscope. The diagnostic results of miniprobe ultrasonography were compared with pathological findings of specimens by biopsy and surgical resection.

RESULTS: Lipomas were visualized as hyperechoic homogeneous masses located in the submucosa with a distinct border. Leiomyomas were visualized as hypoechoic homogeneous mass originated from the muscularis propria. Leiomyosarcomas were shown with inhomogeneous echo and irregular border. Carcinoids were presented as submucosal hypoechoic masses with homogenous echo and distinct border. Lymphangiomas were shown as submocosal hypoechoic masses with cystic septal structures. Malignant lymphomas displayed as hypoechoic masses from mucosa to muscularis propria, while pneumatosis cystoids intestinalis originated from submucosa with a special sonic shadow. One large leiomyoma was misdiagnosed as leiomyosarcoma.

CONCLUSION: Endoscopic miniprobe ultrasonography can provide precise information about the size, layer of origin, border of submucosal tumor of the large intestine and has a high accuracy in the diagnosis of submucosal tumor of the large intestine. Pre-operative miniprobe ultrasonography under colonoscope may play an important role in the choice of therapy for submucosal tumor of the large intestine.