Endoscopic mucosal resection for early colorectal neoplasia: pathologic basis, procedures, and outcomes

Colorectal Endoscopic Submucosal Dissection: Past, Present, and Factors Impacting Future Dissemination

First performed in the stomach for removal of localized gastric tumors, endoscopic submucosal dissection (ESD) has evolved into a technique that is increasingly being employed to resect colorectal lesions. As opposed to endoscopic mucosal resection (EMR), ESD allows the endoscopist to remove large specimens en bloc to provide accurate pathologic evaluation and lower local recurrence rates. ESD is an ideal technique for resection of lesions without lymph node metastases and is becoming the standard of care in Japan as outcomes data has proven it to be equally efficacious, less invasive, and inexpensive as compared with surgery; however, potential risk for complications is high and the procedure is currently not widely available in the Western world. As more interest, endoscopist training, and data supporting the technique's use mount, ESD will also likely become the standard of care in the Western world for resection of localized colorectal lesions.

Endoscopic closure of acute perforations of the GI tract: a systematic review of the literature

BACKGROUND

Surgical repair of endoscopic perforations of the GI tract used to be the standard, but immediate, secure endoscopic closure has become an attractive alternative treatment with the potential to reduce morbidity and mortality.

OBJECTIVE

We aimed to perform a systematic review of the medical literature on endoscopic closure of acute iatrogenic perforations of the GI tract.

DESIGN

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines.

SETTING

Available medical literature from 1966 through November 2013.

PATIENTS

Patients with an acute perforation after an endoscopic procedure that was closed endoscopically.

INTERVENTIONS

Endoscopic closure of an acute perforation of the GI tract.

MAIN OUTCOME MEASUREMENTS

Clinically successful endoscopic closure.

RESULTS

In our search, we identified 726 studies, 702 of which had to be excluded. Twenty-four cohort studies (21 retrospective, 3 prospective) were included in the analysis. No randomized trials were identified. Overall, the methodological quality was low. The 24 studies included described 466 acute perforations in which endoscopic closure was attempted. Successful endoscopic closure was achieved in 419 cases (89.9%; 95% CI, 87%-93%). Successful closure was achieved in 90.2% (n = 359; 95% CI, 87%-93%) of cases by using endoclips, in 87.8% (n = 58; 95% CI, 78%-95%) by using the over-the-scope-clip, and in 100% (n = 2) by using a metal stent.

LIMITATIONS

Low methodological quality of included studies.

CONCLUSION

This systematic review suggests that endoscopic perforation closure is a safe and effective alternative for surgical intervention in selected cases; however, the overall methodological quality was low. Prospective, true consecutive studies are needed to define the definitive role of endoscopic closure of perforations.

High nuclear expression of protein arginine methyltransferase-5 is a potentially useful marker to estimate submucosal invasion in endoscopically resected early colorectal carcinoma

Protein arginine methyltransferase-5 (PRMT5), a major type II arginine methyltransferase, is an important epigenetic modifier with oncogene-like properties because of its ability to repress the expression of tumor suppressor genes. We determined the correlations between PRMT5 expression or its cellular localization and malignant progression, with special reference to invasiveness, in colorectal adenomas and early colorectal carcinomas (CRCs). We performed immunohistochemical detection of PRMT5 in 108 endoscopically resected tissue samples (6 adenomas with low-grade dysplasia, 34 adenomas with high-grade dysplasia, 30 intramucosal carcinomas, and 38 submucosal invasive carcinomas). Early CRC (55 of 68, 80.9%) showed more frequent nuclear expression of PRMT5 than adenoma (15 of 40, 37.5%) (P < 0.001). Furthermore, high (strong staining in ≥ 50% of nuclei) nuclear expression of PRMT5 was more common in submucosal invasive carcinoma (21 of 38, 55.3%) than in intramucosal carcinoma (9 of 30, 30.0%) (P = 0.037). In conclusion, our data suggests that high nuclear expression of PRMT5 is a potentially useful marker for estimating submucosal invasion of early CRC in endoscopically resected specimens.

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.

Local recurrence after endoscopic resection for large colorectal neoplasia: a multicenter prospective study in Japan

OBJECTIVES

Conventional endoscopic resection (CER) is a widely accepted treatment for early colorectal neoplasia; however, large colorectal neoplasias remain problematic, as they necessitate piecemeal resection, increasing the risk of local recurrence. Endoscopic submucosal dissection (ESD) can improve the en bloc resection rate. This study aimed to evaluate local recurrence and its associated risk factors after endoscopic resection (ER) for colorectal neoplasias ≥20 mm.

METHODS

A multicenter prospective study at 18 medium- and high-volume specialized institutions was conducted in Japan. Follow-up colonoscopy was performed after 12 months in cases of complete resection and after 3-6 months in cases of incomplete resection. Local recurrence was confirmed by endoscopic findings and/or pathological analysis.

RESULTS

Follow-up colonoscopy was performed in 1,524 of 1,845 enrolled colorectal neoplasias (mean age, 65 years; 885 men; median tumor size, 32.8 mm). The local recurrence rates were 4.3% (65/1,524), 6.8% (55/808), and 1.4% (10/716) for the entire cohort, for CER, and for ESD, respectively. The relative risks of local recurrence were 0.21 (95% confidence interval, 0.11-0.39) with ESD compared with CER, 0.32 (95% confidence interval, 0.11-0.92) with en bloc ESD compared with en bloc CER, and 0.90 (95% confidence interval, 0.39-2.12) with piecemeal ESD compared with piecemeal CER. Significant factors associated with local recurrence were piecemeal resection, laterally spreading tumors of granular type, tumor size ≥40 mm, no pre-treatment magnification, and ≤10 years of experience in CER, and piecemeal resection only in ESD.

CONCLUSIONS

En bloc ESD reduces the local recurrence rate for large colorectal neoplasias. Piecemeal resection is the most important risk factor for local recurrence regardless of the ER method used.

Assessment and management of the malignant colorectal polyp

Colorectal cancer is the second most common cancer affecting men and women in England. The introduction of National Bowel Cancer Screening in 2006 has led to a rise in the proportion of colorectal cancers detected at an early stage. Many screen-detected cancers are malignant colorectal polyps and may potentially be cured with endoscopic resection, without recourse to the risk of major surgery or prolonged adjuvant therapies. Endoscopic decision making is crucial to select those early lesions that may be suitable for local endoscopic excision as well as identifying lesions for surgical resection, thus avoiding unnecessary surgical intervention in some and ensuring potentially curative surgery in others. This paper uses the current evidence base to provide a structured approach to the assessment of potentially malignant polyps and their management. http://group.bmj.com/products/journals/instructions-for-authors/licence-forms.

Foregut and colonic perforations: practical measures to prevent and assess them

Acute endoscopic perforations of the foregut and colon are rare but can have devastating consequences. There are several principles and practices that can lower the risk of perforation and guide the endoscopist in early assessment when they do occur. Mastery of these principles will lead to overall improved patient outcomes.

Efficacy of endoscopic submucosal dissection for residual or recurrent superficial colorectal tumors after endoscopic mucosal resection

OBJECTIVE

Superficial colorectal tumors can be treated effectively by endoscopic submucosal dissection (ESD). Few data are available on using ESD for residual or recurrent tumors after the first endoscopic resection. This study aimed to evaluate the efficacy of ESD for these lesions.

METHODS

In all, 28 patients with residual or recurrent superficial colorectal tumors were referred to the Kobe University Hospital for ESD. The therapeutic outcomes and the possible factors predictive of procedure difficulties for ESD were analyzed.

RESULTS

In total, 27 (96.4%) patients were successfully treated using ESD. There was no related immediate complication. One patient had a delayed perforation which was then treated surgically. En bloc R0 resection was possible in all the patients and curative resection in 26 patients (92.9%). One invasive cancer was treated surgically. More than one previous endoscopic resection was the only significant predictive factor for the difficulty in performing ESD. None of the patients experienced recurrence during a follow-up of 22 months (range 3-41 months).

CONCLUSIONS

The use of ESD allowed a high rate of en bloc resection for residual or locally recurrent colorectal tumors. Furthermore, these lesions should be treated by ESD as a first-line treatment.

Long-term adenoma recurrence following wide-field endoscopic mucosal resection (WF-EMR) for advanced colonic mucosal neoplasia is infrequent: results and risk factors in 1000 cases from the Australian Colonic EMR (ACE) study

OBJECTIVE

Wide-field endoscopic mucosal resection (WF-EMR) is an alternative to surgery for treatment of advanced colonic mucosal neoplasia up to 120 mm in size, but has been criticised for its potentially high recurrence rates. We aimed to quantify recurrence at 4 months (early) and 16 months (late) following successful WF-EMR and identify its risk factors and clinical significance.

DESIGN

Ongoing multicentre, prospective, intention-to-treat analysis of sessile or laterally spreading colonic lesions ≥20 mm in size referred for WF-EMR to seven academic endoscopy units. Surveillance colonoscopy (SC) was performed 4 months (SC1) and 16 months (SC2) after WF-EMR, with photographic documentation and biopsy of the scar.

RESULTS

1134 consecutive patients were enrolled when 1000 successful EMRs were achieved, of whom 799 have undergone SC1. 670 were normal. Early recurrent/residual adenoma was present in 128 (16.0%, 95% CI 13.6% to 18.7%). One case was unknown. The recurrent/residual adenoma was diminutive in 71.7% of cases. On multivariable analysis, risk factors were lesion size >40 mm, use of argon plasma coagulation and intraprocedural bleeding. Of 670 with normal SC1, 426 have undergone SC2, with late recurrence present in 17 cases (4.0%, 95% CI 2.4% to 6.2%). Overall, recurrent/residual adenoma was successfully treated endoscopically in 135 of 145 cases (93.1%, 95% CI 88.1% to 96.4%). If the initial EMR was deemed successful and did not contain submucosal invasion requiring surgery, 98.1% (95% CI 96.6% to 99.0%) were adenoma-free and had avoided surgery at 16 months following EMR.

CONCLUSIONS

Following colonic WF-EMR, early recurrent/residual adenoma occurs in 16%, and is usually unifocal and diminutive. Risk factors were identified. Late recurrence occurs in 4%. Overall, recurrence was managed endoscopically in 93% of cases. Recurrence is not a significant clinical problem following WF-EMR, as with strict colonoscopic surveillance, it can be managed endoscopically with high success rates.

TRIAL REGISTRATION NUMBER

NCT01368289.

Management of malignant colon polyps: Current status and controversies

Colon cancer remains a significant clinical problem worldwide and in the United States it is the third most common cancer diagnosed in men and women. It is generally accepted that most malignant neoplasms of the colon arise from precursor adenomatous polyps. This stepwise progression of normal epithelium to carcinoma, often with intervening dysplasia, occurs as a result of multiple sequential, genetic mutations-some are inherited while others are acquired. Malignant polyps are defined by the presence of cancer cells invading through the muscularis mucosa into the underlying submucosa (T1). They can appear benign endoscopically but the presence of malignant invasion histologically poses a difficult and often controversial clinical scenario. Emphasis should be initially focused on the endoscopic assessment of these lesions. Suitable polyps should be resected en-bloc, if possible, to facilitate thorough evaluation by pathology. In these cases, proper attention must be given to the risks of residual cancer in the bowel wall or in the surrounding lymph nodes. If resection is not feasible endoscopically, then these patients should be referred for surgical resection. This review will discuss the important prognostic features of malignant polyps that will most profoundly affect this risk profile. Additionally, we will discuss effective strategies for their overall management.

Endoscopic resection as the first-line treatment for early colorectal cancer: comparison with surgery

INTRODUCTION

Endoscopic resection has emerged as an alternative therapeutic option for selected cases of early colorectal cancer. However, even now, few data are available on the comparative effectiveness of endoscopic versus surgical resection of early colorectal cancer. The aim of our study was to compare the clinical outcomes in patients with early colorectal cancer who underwent endoscopic resection and those who underwent surgical resection.

METHODS

292 early colorectal cancer lesions in 287 patients who were treated with either endoscopic resection or colorectal surgery (open or laparoscopic colorectal resection) between January 2005 and December 2010 were retrospectively analyzed. After excluding 54 deep submucosal lesions [and/or tumor budding (Grade 2 or 3)], a total of 168 lesions with mucosal/superficial submucosal invasion were treated by endoscopic resection, and 70 lesions with mucosal/superficial submucosal invasion were treated by colorectal surgery.

RESULTS

In the endoscopic resection group, the en bloc resection rate and the complete resection rate were 91.1 and 91.1%, respectively. In the colorectal surgery group, both the en bloc resection rate and the curative resection rate were 100%. However, using Log rank test in Kaplan-Meier curve, no significant difference in recurrence rate (including metachronous cancer) during the median follow-up period of 37 months (range, 6-98 months) was observed between the two groups (p = 0.647). In addition, a similar morbidity rate was observed for endoscopic resection compared with surgery (5.4 vs. 5.7%, p = 0.760). A significantly shorter hospital stay was observed in the endoscopic resection group than colorectal surgery group [median 2 days (range, 2-29) vs. median 10 days (range, 7-37), p < 0.001).

CONCLUSION

We suggest that endoscopic resection, being equally effective but less invasive than surgery, can be the first-line treatment for well selected early colorectal cancer.

Conventional endoscopic features are not sufficient to differentiate small, early colorectal cancer

AIM: To evaluate the depth of invasion of small, early colorectal cancers (ECCs) using conventional endoscopic features.

METHODS: From January 2005 to September 2011, colonoscopy cohort showed that a total of 72 patients with small colorectal cancers with the size less than 20 mm underwent colonoscopy at the Yonsei University College of Medicine, Seoul, South Korea. Among them, 8 patients were excluded due to incomplete medical records. Finally, a total of 64 ECCs with submucosa (SM) invasion and size less than 20 mm were included. One hundred fifty-two adenomas with size less than 20 mm were included as controls. Nine endoscopic features, including seven morphological findings (i.e., loss of lobulation, excavation, demarcated and depressed areas, stalk swelling, fullness, fold convergence, and bleeding ulcers), pit patterns, and non-lifting signs, were evaluated retrospectively. All endoscopic features were evaluated by two experienced endoscopists who have each performed over 1000 colonoscopies annually for more than five years without knowledge of the histology.

RESULTS: Among the morphological findings, the size of deep submucosal cancers was bigger than that of superficial lesions (16.9 mm vs 12.3 mm, P < 0.001). Also, demarcated depressed areas, stalk swelling, and fullness were more common in deep SM cancers than in superficial tumors (demarcated depressed areas: 52.0% vs 15.7%, P < 0.001; stalk swelling: 100% vs 4.2%, P < 0.001; fullness: 25.0% vs 0%, P = 0.001). Among deep SM cancers, 96% of polyps showed invasive pit patterns, whereas 19.4% of superficial tumors showed invasive pit patterns (P < 0.001). A positive non-lifting sign was more common in deep SM cancers (85.0% vs 28.6%, P < 0.001). Diagnostic accuracy of invasive morphology, invasive pit patterns, and non-lifting signs for deep SM cancers were 71%, 82%, and 75%, respectively.

CONCLUSION: Conventional endoscopic findings were insufficient to discriminate small, deep SM cancers from superficial SM cancers by white light, standard colonoscopy.

Combined morphologic and molecular classification for predicting lymph node metastasis in early-stage colorectal adenocarcinoma

BACKGROUND

Identifying reliable predictors of lymph node (LN) metastasis is clinically important, particularly for optimizing treatments for early colorectal cancer (ECC) patients. This study evaluated risk-predictive models of LN metastasis using several pathologic and molecular ECC parameters.

METHODS

Tissue specimens from 179 patients with histologically confirmed ECC were enrolled. A total of 20 clinicopathological characteristics, including tumor budding, micropapillary structure, and mucinous differentiation, and 22 protein expressions related to cancer invasion in central and invasive front areas were evaluated for their predictive value for LN metastasis.

RESULTS

Alongside conventional histopathological parameters, tumor budding and mucinous differentiation at the invasive front of ECCs and micropapillary structure were found to be independent predictive factors for LN metastasis. Immunohistochemical expressions of CXCL12 and p38-MAPK at the invasive front were also found to be associated with regional LN metastasis in ECC. Analytic logistic models, using combinations of statistically independent parameters, revealed their abilities to predict LN metastasis in ECC. Further, receiver operating characteristic analysis using combinations of 6 or 7 independent variables represented predictive performances (area under curve of 0.956 or 0.960, respectively) for LN metastasis in ECC.

CONCLUSIONS

The combined histomorphologic and molecular factors tested here might be able to predict for LN metastasis in ECC.

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.

Incidence, risk, management, and outcomes of iatrogenic full-thickness large bowel injury associated with 56,882 colonoscopies in 14 Lithuanian hospitals

BACKGROUND

The primary goal of this hospital-based retrospective multicenter case series study was to determine the incidence of large bowel full-thickness injury associated with colonoscopy in Lithuania. We assessed characteristics of patients who were treated as a result of this complication; management and outcomes were the secondary goals of this study.

METHODS

The medical records of patients with iatrogenic large bowel perforations resulting from colonoscopy within the period January 1, 2007, to December 31, 2011, were retrospectively reviewed. Representatives of 14 Lithuanian public and private hospitals participated in the survey.

RESULTS

A total of 56,882 colonoscopies were performed. Forty patients (23 female and 17 male patients) were reported to have iatrogenic full-thickness large bowel injury. Diagnostic and therapeutic colonoscopies resulted in perforation for 28 of 49,795 patients and 12 of 7,087 patients, respectively. A mean age of 70 years and a female preponderance for this complication was revealed. Sigmoid colon and rectosigmoid junction was perforated in 28 patients. All patients underwent surgical management, either primary repair (70.0 %) or bowel resection (30.0 %). Postoperative complications were diagnosed in 15 patients. Immediate treatment resulted in fewer intestinal resections and shorter hospital stays (p < 0.05). Smoking [odds ratio (OR) 14.4, 95 % confidence interval (CI) 1.16-179.8] and a large size perforation site (15 ± 10 vs. 8 ± 5 mm; OR 1.19, 95 % CI 1.03-1.38) were risk factors for developing a postoperative complication after curative surgery. Six patients died. All deaths were related to diagnostic colonoscopy.

CONCLUSIONS

Total incidence of large bowel full-thickness injury in Lithuanian hospitals is 0.07 %. Incidence of this complication after diagnostic and therapeutic colonoscopies is 0.056 and 0.169 %, respectively. The most common site of perforation is sigmoid colon and rectosigmoid junction, at 70 %. Risk rises when colonoscopy is performed in low-volume practice centers. Urgent surgical management resulted in overall mortality rate of 15.0 % and morbidity of 37.5 %.

Autophagy and hypoxia in colonic adenomas related to aggressive features

AIM

The study investigated whether autophagic activity and hypoxia parallel the adenoma-carcinoma sequence.

METHOD

The study comprised 120 tubular adenomas with high-grade dysplasia, including 22 with questionable evidence of invasion, 37 with definite stromal invasion and 29 with severely dysplastic adenoma, 10 traditional serrated adenomas and 22 classical tubular adenomas lacking aggressive features. The samples were stained immunohistochemically for autophagy (LC3A and Beclin-1) and hypoxia-inducible factor1-alpha (HIF1α) markers.

RESULTS

LC3A was detected as diffuse cytoplasmic staining and as dense "stone-like" structures (SLS) within cytoplasmic vacuoles. Beclin-1 reactivity was purely cytoplasmic, whereas that of HIF1α was both cytoplasmic and nuclear. SLS counts in noninvasive, nontransformed areas of tubular adenomas were consistently low (median SLS = 0.5; 200× magnification), whereas a progressive increase was noted from areas of equivocal invasion (median SLS = 1.3; 200× magnification) and intramucosal carcinoma (median SLS = 1.4; 200× magnification) to unequivocal invasive foci (median SLS = 2.1; 200× magnification) (P < 0.0001). A similar association was shown for Beclin-1 and HIF1α expression (P < 0.05). Traditional serrated adenomas yielded low SLS counts and weak HIF1α reactivity, but high cytoplasmic LC3A and Beclin-1 expression (P < 0.01).

CONCLUSION

A hypoxia-driven autophagy in adenomatous polyps, when particularly intense and localized, is commonly associated with early invasion or severely dysplastic adenoma.

Does endoscopic mucosal resection for large colorectal polyps allow ambulatory management?

BACKGROUND

Endoscopic mucosal resection (EMR) is an efficacious endoscopic therapy for large adenoma or confined neoplasia. The most frequent complication is delayed hemorrhage, and hemoclips appear to be an effective therapeutic option. The aim of this study was to determine if large EMR could allow ambulatory management.

METHODS

Colorectal polyps ≥20 mm in size treated by EMR in one endoscopy unit were prospectively included. The period from September 2007 to September 2008 was considered as the reference period (period 1). From September 2008 on, patients were hospitalized in an ambulatory unit. Periods from September 2008 to September 2009 (period 2), from September 2009 to September 2010 (period 3), and from September 2010 to September 2011 (period 4) were compared to the reference period. Patients receiving anticoagulation drugs were excluded from the study.

RESULTS

A total of 138 patients were treated by 139 EMRs for large colorectal polyps. EMRs were completed by at least one clip per centimeter in 10.7 %, 30.2 % (p = NS), 50 % (p = 0.015), and 76 % (p = 0.001). Ambulatory EMRs were performed in 21 %, 52.4 % (p = 0.008), 67.6 % (p = 0.02), and 88.2 % (p = 0.004) of cases during periods 1, 2, 3, and 4. The complication rate was stable during the four periods. No patients with more than one hemoclip per EMR centimeter experienced delayed bleeding.

CONCLUSIONS

The low complication rate during the four periods allows us to consider ambulatory EMR for large colorectal lesions ≥20 mm in diameter as an option. One hemoclip per centimeter may help prevent delayed hemorrhage in patients without anticoagulation drugs.

Risk factors for residual cancer and lymph node metastasis after noncurative endoscopic resection of early colorectal cancer

BACKGROUND

Endoscopic resection could be a curative treatment for early colorectal cancer without the possibility of lymph node metastasis. However, if the resection margin is positive, and there is a risk of lymph node metastasis, additional surgery should be performed.

OBJECTIVE

The aim of this study was to investigate the characteristics of patients who underwent additional surgery to determine risk factors associated with residual tumor and lymph node metastasis.

DESIGN

This study is a retrospective analysis.

SETTINGS

This study was conducted at a tertiary academic hospital.

PATIENTS

We evaluated 85 patients who underwent additional surgery with curative intent after endoscopic resection for early colorectal cancer at the Samsung Medical Center, Seoul, South Korea, between January 2001 and April 2010.

MAIN OUTCOME MEASURES

We identified risk factors associated with residual tumor or lymph node metastasis in surgical specimens after noncurative endoscopic resection for early colorectal cancer.

RESULTS

Among 85 patients who underwent additional surgery after noncurative endoscopic resection, 76 (89.4%) had submucosal invasion greater than 1000 μm. Twenty-one (24.7%) and 25 patients (29.4%) had a positive lateral or vertical resection margin, and 11 patients (12.9%) had inadequate lifting sign. After additional surgery, patients were divided into 2 groups according to the presence or absence of residual tumor and/or lymph node metastasis. There was no significant difference between the groups in positive lateral margin, but there was a significant difference in positive vertical margin (p = 0.015 with an OR of 15.02). In patients with inadequate lifting sign, the OR was 13.68 (p = 0.013).

LIMITATIONS

This study was limited by its retrospective nature.

CONCLUSION

There is a greater need for additional surgery in cases with positive vertical resection margin or inadequate lifting sign, because the risk of residual tumor and lymph node metastasis is higher than in other cases.

High efficacy of endoscopic submucosal dissection for rectal laterally spreading tumors larger than 3 cm

BACKGROUND

Endoscopic submucosal dissection (ESD) was recently developed to allow en bloc resection of early neoplasia of the GI tract, including colorectal neoplasia. The endoscopic technique is technically demanding and not yet standardized, and new devices are needed.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of a new device that combines the functions of injection and cutting.

DESIGN

Prospective, pilot, single-arm study.

METHODS

Consecutive patients with rectal laterally spreading tumors (LSTs) 3 cm or larger unsuitable for en bloc resection were enrolled. ESD was performed with a new device that allows cutting and coagulation as well as a needleless, tissue-selective mucosal and submucosal elevation through an axial water-jet channel.

MAIN OUTCOME MEASUREMENT

The primary endpoint of the study was the en bloc resection rate achieved with ESD in a Western hospital setting.

RESULTS

Overall, ESD was attempted in 40 consecutive patients (27 male, mean age 65.3 years) with rectal LSTs larger than 3 cm (72.5% LSTs, nongranular type, 5% depressed type, 22.5% protruding type). The mean lesion size was 46.8 ± 10.9 mm (range 33-80 mm). The mean procedure time was 86.1 ± 35.5 minutes (range 40-190 minutes). The en bloc resection rate was 90% (36/40). In the remaining patients, resection was completed with a piecemeal approach. The rate of curative resection (R0) was 32 of 40 LSTs (80%). Two patients with submucosal invasion were referred for surgery. Perforation occurred in 1 patient (2.5%), which was managed conservatively. Postoperative bleeding occurred in 2 patients (5%) and was treated by endoscopic hemostasis.

LIMITATIONS

Single-center study with a relatively small number of patients.

CONCLUSIONS

ESD is a safe and effective method to provide en bloc and curative resection of large rectal LSTs. The operating time and adverse event rate were comparable to those of previously published data from Japanese experts.

Hood colonoscopy in trainees: a useful adjunct to improve the performance

BACKGROUND

The use of a transparent hood to improve colonoscopic performance has recently been proposed.

AIMS

The purpose of this study was to evaluate whether using the hood might improve the cecal intubation rate, cecal intubation time, number of attempts needed to intubate the ileo-cecal valve, and polyp detection rate in trainees.

METHODS

Patients undergoing colonoscopy (n = 378) were randomized in two groups, one studied with hood colonoscopy (n = 179) and the other (n = 199) with standard examination.

RESULTS

No differences were found between hood and standard colonoscopy with respect to cecal intubation rate (95 vs 92 %), whereas hood colonoscopy significantly shortened the cecal intubation time, the number of attempts needed to intubate the ileo-cecal valve, and the overall polyp detection rate (p < 0.01 for all these variables).

CONCLUSIONS

Hood colonoscopy might represent a useful adjunct to standard colonoscopy, especially improving the performance of endoscopic trainees.

Promptness of diagnosis is the main prognostic factor after colonoscopic perforation

AIM

The authors present their experience of colonoscopic perforation and its management, with an analysis of factors affecting outcome.

METHOD

During the last 10 years, 22 cases of colonoscopic perforation (CP) were identified in two different institutions. Multiple logistic regression analysis was used to identify significant predictors of morbidity and mortality.

RESULTS

Morbidity and mortality rates were 31% and 13.6%, respectively. Prompt diagnosis was the most powerful predictor of outcome of CP. Multiple logistic regression analysis showed that morbidity and mortality were significantly related to a delay in diagnosis of more than 24 h (P = 0.03 and P = 0.04).

CONCLUSION

The results emphasize the importance of prompt assessment of a patient who develops symptoms after colonoscopy.

Clinical outcomes and factors related to resectability and curability of EMR for early colorectal cancer

BACKGROUND

EMR has emerged as an alternative therapeutic option for selected cases of early colorectal cancer (ECC). However, the factors associated with resectability and curability of EMR for ECC remain unknown.

OBJECTIVE

To investigate clinical outcomes and factors related to resectability and curability in ECC cases treated with EMR.

DESIGN

Retrospective study.

SETTING

Tertiary-care academic medical center.

PATIENTS

This study involved all patients in whom EMR was performed for ECC at Severance Hospital between March 1997 and August 2007. A total of 236 cases of ECC occurring in 231 patients (66.2% men) were enrolled.

INTERVENTION

EMR. Curative surgical resection and lymph node dissection were used in cases that were incompletely cured by EMR.

MAIN OUTCOME MEASUREMENTS

Resectability, curability, and recurrence.

RESULTS

Complete cure was achieved for 162 lesions (68.6%). Of the remaining 74 cases (31.4%), 69 (29.2%) were incompletely cured, and the other 5 (2.1%) had an undetermined resection status and ultimately required supplementary surgical resection for curative treatment. Location on the right side of the colon, piecemeal resection, and submucosal carcinoma were independently associated with incomplete resection, whereas depressed tumor type was independently related to incomplete cure. Among the ECC cases completely cured by EMR and followed for more than a year (n = 118), local recurrence was observed in one case (0.8%) during the median follow-up period of 39.4 months (range 12.4-123.1 months).

LIMITATIONS

Single-center, retrospective study.

CONCLUSION

Our data show that EMR is feasible and could be an effective option for treatment of ECC if the technique is applied with the appropriate indications.

Endoscopic mucosal resection in colorectal lesion: a safe and effective procedure even in lesions larger than 2 cm and in carcinomas

CONTEXT: Endoscopic mucosal resection is a minimally invasive technique used in the treatment of colorectal neoplasms, including early carcinomas of different size and morphology. OBJECTIVES: To evaluate procedure safety, efficacy, outcomes, and recurrence rate in endoscopic mucosal resection of colorectal lesions. METHODS: A total of 172 lesions in 156 patients were analyzed between May 2003 and May 2009. All lesions showed pit pattern suggestive of neoplasia (Kudo types III-V) at high-magnification chromocolonoscopy with indigo carmine. The lesions were evaluated for macroscopic classification, size, location, and histopathology. Lesions 20 mm or smaller were resected en bloc and lesions larger than 20 mm were removed using the piecemeal technique. Complications and recurrence were analyzed. Patients were followed up for 18 months. RESULTS: There were 83 (48.2%) superficial lesions, 57 (33.1%) depressed lesions, 44 (25.6%) laterally spreading tumors, and 45 (26.2%) protruding lesions. Mean lesion size was 11.5 mm ± 9.6 mm (2 mm-60 mm). Patients' mean age was 61.6 ± 12.5 years (34-93 years). Regarding lesion site, 24 (14.0%) lesions were located in the rectum, 68 (39.5%) in the left colon, and 80 (46.5%) in the right colon (transverse, ascending, and cecum). There were 167 (97.1%) neoplasms: 142 (82.5%) adenomatous lesions, 24 (14.0%) intramucosal carcinomas, and 1 (0.6%) invasive carcinoma. En bloc resection was performed in 158 (91.9%) cases and piecemeal resection in 14 (8.1%). Bleeding occurred in 5 (2.9%) cases. Recurrence was observed in 4.1% (5/122) of cases and was associated with lesions larger than 20 mm (P<0.01), piecemeal resection (P<0.01), advanced neoplasm (P = 0.01), and carcinoma compared to adenoma (P = 0.04). CONCLUSIONS: Endoscopic mucosal resection of colorectal lesions is a safe and effective procedure, with low complication and local recurrence rates. Recurrence is associated with lesions larger than 20 mm and carcinomas.

Laparoscopic-monitored colonoscopic polypectomy: a multimodality method to avoid segmental colon resection

AIM

In some patients with adenoma, snare polypectomy may be technically impossible owing to angulation of the colon or after previous surgery. This may result in a segmental colonic resection, if malignant invasion is thought to be likely. Laparoscopic mobilization of the colon to enable a simultaneous colonoscopy can avoid this difficulty.

METHOD

A feasibility study was performed in 11 patients for whom endoscopic removal was technically impossible due to fibrosis after previous surgery or to anatomical difficulty. In 10, adenoma (histologically benign) had been diagnosed during diagnostic colonoscopy and in the remaining patient the indication was rectal bleeding.

RESULTS

It was possible to perform a full colonoscopy after laparoscopic mobilization in all cases. In nine of the 10 patients with adenoma 11 tubulovillous adenomas were removed endoscopically, and in one the tumour was too large for endoscopic resection even after full mobilization. A laparoscopic segmental resection was performed in this case. In the patient with rectal bleeding, colonoscopy revealed an angiodysplasia of the caecum, also treated by resection. Apart from the two patients having resection, all patients were discharged within 24 h of the procedure. During endoscopic follow up (4-27 months) there were no recurrences.

CONCLUSIONS

Combined laparoscopy and endoscopy enabled removal of adenomas otherwise inaccessible for endoscopic techniques. Thus, segmental colon resections can be avoided in most of these patients.

Endoscopic mucosal resection outcomes and prediction of submucosal cancer from advanced colonic mucosal neoplasia

BACKGROUND & AIMS

Large sessile colonic polyps usually are managed surgically, with significant morbidity and potential mortality. There have been few prospective, intention-to-treat, multicenter studies of endoscopic mucosal resection (EMR). We investigated whether endoscopic criteria can predict invasive disease and direct the optimal treatment strategy.

METHODS

The Australian Colonic Endoscopic (ACE) resection study group conducted a prospective, multicenter, observational study of all patients referred for EMR of sessile colorectal polyps that were 20 mm or greater in size (n=479, mean age, 68.5 y; mean lesion size, 35.6 mm). We analyzed data on lesion characteristics and procedural, clinical, and histologic outcomes. Multiple logistic regression analysis identified independent predictors of EMR efficacy and recurrence of adenoma, based on findings from follow-up colonoscopy examinations.

RESULTS

Risk factors for submucosal invasion were as follows: Paris classification 0-IIa+c morphology, nongranular surface, and Kudo pit pattern type V. The most commonly observed lesion (0-IIa granular) had a low rate of submucosal invasion (1.4%). EMR was effective at completely removing the polyp in a single session in 89.2% of patients; risk factors for lack of efficacy included a prior attempt at EMR (odds ratio [OR], 3.8; 95% confidence interval, 1.77-7.94; P=.001) and ileocecal valve involvement (OR, 3.4; 95% confidence interval, 1.20-9.52; P=.021). Independent predictors of recurrence after effective EMR were lesion size greater than 40 mm (OR, 4.37; 95% confidence interval, 2.43-7.88; P<.001) and use of argon plasma coagulation (OR, 3.51; 95% confidence interval, 1.69-7.27; P=.0017). There were no deaths from EMR; 83.7% of patients avoided surgery.

CONCLUSIONS

Large sessile colonic polyps can be managed safely and effectively by endoscopy. Endoscopic assessment identifies lesions at increased risk of containing submucosal cancer. The first EMR is an important determinant of patient outcome-a previous attempt is a significant risk factor for lack of efficacy.

Endoscopic colorectal imaging and therapy

PURPOSE OF REVIEW

Colorectal cancer screening and prevention is a pivotal element in every gastroenterologist practice. Recent advances in imaging technology and treatment opened the field for endoscopic management of large flat colorectal polyps and early cancer.

RECENT FINDINGS

High-definition white light colonoscopy allowed for better characterization of colon polyps, particularly flat lesions. Chromoendoscopy facilitated the identification of colon polyps as well as better endoscopic polyp characterization, with strong correlation with final pathological diagnosis, opening the field of 'virtual' biopsy. One particular technology, confocal endomicroscopy can magnify an image approximately 1000 times resembling optical microscopy with very good correlation with histology. Endoscopic mucosal resection has gained great acceptance to manage flat colorectal polyps with the two major complications being bleeding and perforation, both now under 5% in experienced hands. Endoscopic submucosal resection was developed to increase en-bloc resection (less residual disease) of a flat colorectal lesion but one has to accept a higher perforation rate around 10%.

SUMMARY

Current technology allows for better polyp identification and characterization, which can be managed endoscopically.

Smoothelin is a specific and robust marker for distinction of muscularis propria and muscularis mucosae in the gastrointestinal tract

AIMS

As tumour specimens and biopsy specimens become smaller, recognition of anatomical structures relevant for staging is increasingly challenging. So far no marker is known that reliably discriminates between muscularis propria (MP) and muscularis mucosae (MM) of the gastrointestinal tract. Recently, smoothelin expression has been shown to differ in MP and MM of the urinary bladder. We aimed to analyse the expression of smoothelin in the gastrointestinal tract in MP and MM in order to define a novel diagnostic tool to identify MM bundles.

METHODS AND RESULTS

The expression of smoothelin was analysed immunohistochemically in comparison with alpha-smooth muscle actin (alpha-SMA) in specimens from colon, stomach and oesophagus (n = 107). In contrast to alpha-SMA, which equally stained MM and MP, absent or significantly weaker smoothelin expression was found in MM was found, which was particularly valid in colon and gastric specimens.

CONCLUSIONS

The combination of smoothelin and SMA represents a robust marker to discriminate MM from MP in the gastrointestinal tract.

Malignant colorectal polyps

Nowadays, the number of cases in which malignant colorectal polyps are removed is increasing due to colorectal cancer screening programmes. Cancerous polyps are classified into non-invasive high grade neoplasia (NHGN), when the cancer has not reached the muscularis mucosa, and malignant polyps, classed as T1, when they have invaded the submucosa. NHGN is considered cured with polypectomy, while the prognosis for malignant polyps depends on various morphological and histological factors. The prognostic factors include, sessile or pedunculated morphology of the polyp, whether partial or en bloc resection is carried out, the degree of differentiation of the carcinoma, vascular or lymphatic involvement, and whether the polypectomy resection margin is tumor free. A malignant polyp at T1 is considered cured with polypectomy if it is a pedunculated polyp (Ip of the Paris classification), it has been completely resected, it is not poorly differentiated, the resection edge is not affected by the tumor and there is no vascular or lymphatic involvement. The sessile malignant polyp (Is of the Paris classification) at T1 is considered not cured with polypectomy. Only in some cases (e.g. older people with high surgical risk) local excision (polypectomy or endoscopic submucosal dissection or conventional endoscopic mucosal resection) is considered the definitive treatment.

Colonoscopic perforation: incidence, risk factors, management and outcome

This review discusses the incidence, risk factors, management and outcome of colonoscopic perforation (CP). The incidence of CP ranges from 0.016% to 0.2% following diagnostic colonoscopies and could be up to 5% following some colonoscopic interventions. The perforations are frequently related to therapeutic colonoscopies and are associated with patients of advanced age or with multiple comorbidities. Management of CP is mainly based on patients' clinical grounds and their underlying colorectal diseases. Current therapeutic approaches include conservative management (bowel rest plus the administration of broad-spectrum antibiotics), endoscopic management, and operative management (open or laparoscopic approach). The applications of each treatment are discussed. Overall outcomes of patients with CP are also addressed.