Colonoscopic resection of lateral spreading tumours: a prospective analysis of endoscopic mucosal resection

Wide field endoscopic resection for advanced colonic mucosal neoplasia: current status and future directions

Most colonic adenomas are ≤ 10 mm and are routinely treated by colonoscopic polypectomy with long-term health benefits. Nonpolypoid lesions ≥ 20 mm, whether sessile or flat and laterally spreading, are forms of advanced mucosal neoplasia that cannot be managed by conventional polypectomy and are often referred for surgery. However, the majority of these lesions when carefully assessed are found to be noninvasive and can be safely and effectively treated by advanced endoscopic techniques including endoscopic mucosal resection or endoscopic submucosal dissection with resultant cost, morbidity, and mortality benefits. Lesion assessment is a critical component. Enhanced imaging methods provide the opportunity for accurate pathological characterization, informing treatment decisions, without the need for previous histologic confirmation. Techniques of advanced endoscopic resection are still in evolution and further improvements, including hybrid techniques, bringing less technically challenging and shorter procedures with superior safety can be reasonably expected in the next decade. Safety is a fundamental consideration. Methods of early recognition of complications, risk stratification, and management pathways are being developed and refined. Standardization, validation, and adoption of these technological developments will improve endoscopic interpretation and therapy and in combination with an increased understanding of adenoma molecular biology, will result in a progressively more individualized lesion-specific endoscopic approach. The future of advanced endoscopic resection in the colon is promising, and the next few years should see the boundaries of endoscopic resection expand well beyond the limits of what we know today.

Endoscopic mucosal resection of giant laterally spreading tumors with submucosal injection of hydroxyethyl starch: comparative study with normal saline solution

BACKGROUND

Normal saline (NS) plus epinephrine (E) is the traditionally used solution as submucosal fluid cushion for a safe and effective endoscopic mucosal resection (EMR) of sessile colorectal polyps. It was hypothesized that hydroxyethyl starch (HES), an inexpensive and easily available solution might be an ideal solution for prolonged elevation of submucosal cushion for an easy and safe EMR of giant colorectal lateral spreading tumors (LSTs).

PATIENTS AND METHODS

During a 6-year period, patients suffering from colorectal LSTs with a diameter of ≥ 30 mm were randomized to undergo EMR by using either HES+E (group A) or NS+E (group B) for submucosal fluid cushion. All patients who had undergone a colonoscopy set the diagnosis of LSTs. The LSTs were examined with standard white light and narrow-band imaging to accurately delinate their margins before resection. The initial volume of injected solution, the additional amount to maintain the submucosal cushion, the duration of submucosal elevation and post-EMR-related complications were recorded. After EMR, patients had a standard follow-up at 3, 6, and 12 months and further if it was necessary using total colonoscopy.

RESULTS

Forty-nine patients suffering from giant LSTs were included in the study. No difference between the 2 groups was observed in patients' characteristics, size of LSTs, and the initial volume of injected solution. However, the additional amount of solution to maintain submucosal elevation was lower in group A (median, 4 mL; range, 2 to 25) than in group B (median, 6 mL; range, 3 to 8; P=0.001). Moreover, submucosal elevation had a statistically longer duration in group A (median, 18.5 min; range, 14.5 to 28.4) than in group B (median, 20.15 min, range, 9.6 to 13.4; P<0.001), and there was a statistical difference on total procedure time in favor of group A [group A, 20.15 min (12 to 32.5) vs. group B, 22.8 min (18 to 34.5)]. One case of macroperforation, 2 cases of postpolypectomy syndrome, and 1 case of EMR-related bleeding were observed in the HES+E group, whereas 6 cases of EMR-related bleeding were observed in the NS+E group. During a median follow-up of 32 and 34 months, for HES+E and NS+E groups, respectively, 5 and 7 recurrences were observed, which were all treated endoscopically.

CONCLUSIONS

HES+E injection produces a more prolonged submucosal elevation and lowers total procedure time than NS+E; however, the safety of EMR is not influenced.

Tumor budding as a risk factor of lymph node metastasis in submucosal invasive T1 colorectal carcinoma: a retrospective study

Background

This study was designed to identify risk factors for lymph node metastasis of early stage colorectal cancer, which was confirmed to a carcinoma that invaded the submucosa after radical resection.

Methods

In total, 55 patients revealing submucosal invasive colorectal carcinoma on pathology who underwent curative radical resection at the Department of Surgery, St. Vincent’s Hospital, The Catholic University of Korea from January 2007 to September 2010 were evaluated retrospectively. Tumor size, depth of submucosal invasion, histologic grade, lymphovascular invasion, tumor budding, and microacinar structure were reviewed by a single pathologist. Student t-test for continuous variables and Chi-square test for categorical variables were used for comparing the clinicopathological features between two groups (whether lymph node involvement existed or not). Continuous variables are expressed as the mean ± standard error while statistical significance is accepted at P < 0.05.

Results

The mean age of 55 patients (34 males and 21 females) was 61.2 ± 9.6 years (range, 43–83). Histologically, eight (14.5%) patients had metastatic lymph node. In the univariate analysis, tumor budding (P = 0.047) was the only factor that was significantly associated with lymph node metastasis. Also, the tumor budding had a sensitivity of 83.3%, a specificity of 60.5%, and a negative predictive value of 0.958 for lymph node metastasis in submucosal invasive T1 colorectal cancer.

Conclusions

The tumor budding seems to have a high sensitivity (83.3%), acceptable specificity (60.5%), and a high negative predictive value (0.958). A close examination of pathologic finding including tumor budding should be performed in order to manage early CRC properly.

Clinical outcomes for patients with perforations during endoscopic submucosal dissection of laterally spreading tumors of the colorectum

BACKGROUND

Endoscopic submucosal dissection (ESD) for colorectal neoplasms is not widely performed because of the high risk of perforation. Perforations are divided into macroperforations and microperforations. Currently, there is a limited amount of clinical data on the outcome of patients with these types of perforations during colonic ESD. The aim of this study was to investigate the clinical outcome of patients who sustained colon perforations during ESD. We also compared the clinical outcome of patients with microperforations and those with macroperforations.

METHODS

This study enrolled 101 patients with colorectal laterally spreading tumors (LST) who underwent ESD. We retrospectively reviewed their medical records, including patient demographic data and the clinical, endoscopic, and pathologic features. In the cases where perforation had occurred, the course of hospital treatment was analyzed. All ESD-related perforations were divided into macroperforations and microperforations. A macroperforation was defined as a gross perforation that occurred during an ESD procedure and a microperforation was defined by free air visible on X-rays after the procedure.

RESULTS

Of the 101 enrolled patients, 9 (8.9 %) developed perforations. The most common tumor morphology was nongranular-type LST (5 of 9 cases, 55.6 %) based on endoscopic examination. Five patients had microperforations and four had macroperforations. All macroperforations were closed primarily by endoclips during ESD. The endoscopic characteristics did not differ between the groups. However, the length of hospital stay and the mean duration of NPO and antibiotic treatments were longer for microperforation patients. All patients had conservative nonsurgical management such as fasting, intravenous antibiotics, and nasogastric tube drainage.

CONCLUSIONS

The clinical complications for microperforation patients were worse than those for macroperforation patients. However, the clinical prognoses of patients with perforations that occur during colonic ESD are favorable.

Approach to rectal cancer surgery

Rectal cancer is a distinct subset of colorectal cancer where specialized disease-specific management of the primary tumor is required. There have been significant developments in rectal cancer surgery at all stages of disease in particular the introduction of local excision strategies for preinvasive and early cancers, standardized total mesorectal excision for resectable cancers incorporating preoperative short- or long-course chemoradiation to the multimodality sequencing of treatment. Laparoscopic surgery is also increasingly being adopted as the standard rectal cancer surgery approach following expertise of colorectal surgeons in minimally invasive surgery gained from laparoscopic colon resections. In locally advanced and metastatic disease, combining chemoradiation with radical surgery may achieve total eradication of disease and disease control in the pelvis. Evidence for resection of metastases to the liver and lung have been extensively reported in the literature. The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastases is showing promise in achieving locoregional control of peritoneal dissemination. This paper summarizes the recent developments in approaches to rectal cancer surgery at all these time points of the disease natural history.

Predictive factors of local recurrence after endoscopic piecemeal mucosal resection

BACKGROUND

Endoscopic piecemeal mucosal resection (EPMR) is a widely accepted treatment for colorectal tumefaction. However, as it is associated with a significant recurrence rate, the technique remains controversial. The purpose of our study was to evaluate the risk factors for the local recurrence of colorectal neoplasms after EPMR.

METHODS

The study population of our retrospective evaluation comprised 222 patients who had undergone EPMR from January 2002 to July 2007 and who had had at least 1 surveillance colonoscopy 3-6 months after the initial treatment.

RESULTS

Local recurrence was detected in 42 patients (19%) between 6 and 15 months after EPMR. Our multivariate analysis revealed that the resection of 5 or more neoplasm specimens, compared with fewer than 5, was 3 times more likely to result in local recurrence (P = 0.005). No statistically significant correlation of local recurrence with lesion size, location, macroscopic type, or histology was detected.

CONCLUSION

The removal of 5 or more neoplasm specimens is an independent risk factor for local recurrence after EPMR. Careful colonoscopic surveillance should be performed after multiple piecemeal resection.

Clinical outcomes of endoscopic submucosal dissection and endoscopic mucosal resection for laterally spreading tumors larger than 20 mm

BACKGROUND AND AIMS

Colorectal laterally spreading tumors (LST) > 20 mm are usually treated by endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR). Endoscopic piecemeal mucosal resection (EPMR) is sometimes required. The aim of our study was to compare the outcomes of ESD and EMR, including EPMR, for such LST.

METHODS

A total of 269 consecutive patients with a colorectal LST > 20 mm were treated endoscopically at our hospital from April 2006 to December 2009. We retrospectively evaluated the complications and local recurrence rates associated with ESD, hybrid ESD (ESD with EMR), EMR, and EPMR.

RESULTS

ESD and EMR were performed successfully for 89 and 178 LST, respectively: 61 by ESD; 28 by hybrid ESD; 70 by EMR; and 108 by EPMR. Between-group differences in perforation rates were not significant. Local recurrence rates in cases with curative resection were as follows: 0% (0/56) in ESD; 0% (0/27) in hybrid ESD; 1.4% (1/69) in EMR; and 12.1% (13/107) in EPMR; that is, significantly higher in EPMR. No metastasis was seen at follow up. The recurrence rate for EPMR yielding ≥ three pieces was significantly high (P < 0.001). All 14 local recurrent lesions were adenomas that were cured endoscopically.

CONCLUSIONS

As for safety, ESD/hybrid ESD is equivalent to EMR/EPMR. ESD/hybrid ESD is a feasible technique for en bloc resection and showed no local recurrence. Although local recurrences associated with EMR/EPMR were seen, which were conducted based on our indication criteria, all local recurrences could obtain complete cure by additional endoscopic treatment.

Efficacy of endoscopic mucosal resection with circumferential incision for patients with large colorectal tumors

BACKGROUND & AIMS

Treatment of large colorectal neoplasms (>20 mm in diameter) by conventional endoscopic mucosal resection (EMR) often results in piecemeal resection that requires further intervention. We evaluated the efficacy of EMR with circumferential incision (CEMR).

METHODS

From March 2008-July 2009, we resected 24 large colorectal neoplasms measuring 20-40 mm in diameter by using the CEMR technique. CEMR was performed by using a ball-tip bipolar needle knife with a snaring technique. After the injection of glycerol into the submucosal layer, a circumferential incision was made, and the neoplasm was resected by snaring. All lesions that showed a noninvasive pattern were diagnosed by magnifying chromoendoscopy as adenomas or intramucosal or submucosal superficial cancers. The number of en bloc resections and complications and the overall procedure time were determined.

RESULTS

The proportions of en bloc and 2-piece resections by CEMR were 67% (16/24) and 17% (4/24), respectively. The median (interquartile range) time for CEMR completion was 40 minutes (30-63 minutes). No postsurgery complications occurred in any patient.

CONCLUSIONS

CEMR might provide acceptable clinical outcomes for patients with large colorectal neoplasms. It results in a low incidence of incomplete treatments and low risk of complications.

Endoscopic submucosal dissection with or without snaring for colorectal neoplasms

BACKGROUND

Despite a high en bloc resection rate, its technical difficulty and risk of complications limit the widespread use of colorectal endoscopic submucosal dissection (ESD).

OBJECTIVE

To analyze outcomes after colorectal ESD and ESD with snaring (ESD-S), a simplified modification of ESD.

DESIGN

A retrospective observational study.

SETTING

A single, tertiary-care, referral center.

PATIENTS AND INTERVENTION

ESD was performed on 163 lesions in 162 patients and ESD-S on 74 lesions in 71 patients. All lesions were nonpedunculated colorectal neoplasms of 15 mm or larger.

MAIN OUTCOME MEASUREMENTS

We analyzed procedure-related variables such as en bloc resection rate, procedure time, and complications. Histopathologic results were reviewed. Follow-up data were analyzed.

RESULTS

The en bloc resection rate was higher for ESD than for ESD-S (87% vs 64%, P < .01). The histologically complete resection rate was also higher for ESD. However, both rates for resection of lesions of <20 mm were not different between ESD and ESD-S groups. The rates of perforation and bleeding were similar for both groups. Submucosal cancers were present in 21% and 31% of the ESD and ESD-S groups, respectively. One patient from each group developed a local adenoma recurrence.

LIMITATIONS

Retrospective design.

CONCLUSION

Both ESD and ESD-S were safe and effective for resection of colorectal neoplasms. The higher en bloc resection rate for ESD suggests that it should be the first option for resection of suspected superficial submucosal cancers in the colorectum. ESD-S can be a good alternative to ESD for en bloc resection of colorectal lesions of <20 mm.

Endoscopic submucosal dissection of scar-embedded rectal polyps: a prospective study (Esd in scar-embedded rectal polyps)

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) was developed for en bloc resection of superficial neoplasm of the digestive tract. We evaluated feasibility and safety of ESD, as a salvage therapy of large refractory rectal polyps, in a tertiary care setting.

METHODS

We prospectively enrolled in the present study and treated by ESD 11 consecutive patients with rectal polyps (median diameter 3.5 cm; range 2-5 cm), who had previously undergone several attempts of endoscopic resection and not suitable for further standard endoscopic treatment. The ESD was carried out with a standard needle knife. Follow up examinations were scheduled at 3, 6, 12 and 24 months.

RESULTS

We achieved apparently complete resection of polyps in 10/11 patients. In one patient ESD was interrupted and the pathology of the resected fragment showed deep submucosal infiltration; this patient underwent surgery. Deep and lateral margins were shown to be free of neoplasm (radical resection) in six out of 11 patients. However all the 10 patients with apparently complete resection were free of recurrence after a mean follow up of 19.2 months (12-24). A T1 adenocarcinoma was radically resected by ESD, with no recurrence. We recorded 2 cases of subcutaneous emphysema, both treated conservatively.

CONCLUSIONS

Radical resection is difficult to be achieved by ESD in patients with rectal scar-embedded polyps. Nevertheless ESD may be proposed as a definitive treatment of selected patients with refractory polyps, avoiding surgery in the majority of them.

Polyp recurrence after endoscopic mucosal resection of sessile and flat colonic adenomas

BACKGROUND

Endoscopic mucosal resection (EMR) is used for treatment of sessile and flat colonic adenomas. There is limited data comparing polyp recurrence between piecemeal and en-bloc resections.

AIM

The purpose of this study was to evaluate the incidence density and predictive factors for polyp recurrence after piecemeal and en-bloc resections.

METHODS

Patients undergoing EMR of flat or sessile adenomas≥10 mm were included. Incidence density (ID) and incidence rate ratio (IRR) of polyp recurrence were calculated. Predictive factors for recurrence were assessed by multivariate analysis using logistic regression.

RESULTS

A total of 105 patients (males 54, mean age 68) with 121 polyps were included. Sixty-seven polyps (mean size±SD, 23.3±9.2 mm) were resected piecemeal and 54 polyps (mean size 14.7±5.1 mm) were resected en-bloc. There were 12 recurrences in the piecemeal group and two in the en-bloc group. The ID of polyp recurrence in the piecemeal group was 13.1 (95% CI 7.43-23.03) and in the en-bloc group was 2.7 (95% CI 0.67-10.78) per 100 person-years of follow-up. Piecemeal resections were 5.5 (95% CI 1.1-30.48, P=0.045) times and flat polyps were 6.6 (95% CI 1.22-35.53, P=0.028) times more likely to result in recurrence compared to en-bloc resections and sessile polyps, respectively. In the piecemeal group, additional use of argon plasma coagulation (APC) did not affect the recurrence (OR 0.46, P=0.29).

CONCLUSIONS

Piecemeal resections and flat polyps are associated with higher recurrence following EMR. Additional use of APC did not affect the recurrence rates after piecemeal resection.

Endoscopic submucosal dissection for colonic lesions: why and how should we do it?

Endoscopic submucosal dissection (ESD) is a safe and effective alternative to surgery for large non-polypoid colonic lesions and early colorectal carcinoma. In this article, we discuss the development, efficacy and safety of ESD. As the incidence of colorectal cancer is rapidly increasing in Asia, we advocate standardization of ESD program, including patient selection, hardware prerequisites, and training of operators.

Endoscopic snare resection followed by laser ablation in the treatment of large, sessile rectal adenomas

BACKGROUND AND AIMS

Large sessile rectal adenomas can be difficult to eradicate, and different treatment modalities are available. The aim of this study was to evaluate outcome after endoscopic snare resection followed by Nd:YAG laser ablation.

MATERIAL AND METHODS

Over a 10-year period 92 of 99 (93%) patients were registered prospectively and attended follow-up examinations with endoscopy and biopsies.

RESULTS

Fifty-four (59%) men and 38 (41%) women were included; 67 patients (73%) had high grade (severe) intraepithelial dysplasia or intramucosal neoplasia. The adenomas ranged from 2-9 cm (median 4 cm) in diameter, and were located 2-15 cm (median 5 cm) from the anal verge. A median of two (range 1-6) piecemeal snare resection sessions and a median of one (range 1-7) laser treatments were performed for each patient. Complete eradication was achieved in 86 patients (93%). Over a median follow-up period of 26 months, 20/86 (23%) suffered local recurrence, eight of whom were given a second laser treatment without developing further recurrence. In five of eight frail patients considered unsuitable for more radical treatment, repeated laser treatment was effective in keeping the adenoma small and symptoms at a minimum. As a whole the treatment was successful in 74/92 (80%) and partially successful in 5/92 (5%) of the patients.

CONCLUSIONS

Snare resection followed by laser ablation is safe and still has a place in the treatment of old, frail patients with large rectal adenomas. However, there is a risk of missing an infiltrating carcinoma, and other treatment options are preferable in fit patients.

Comparing endoscopic submucosal dissection with transanal resection for non-invasive rectal tumor: a retrospective study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is an alternative to transanal resection (TAR) in treating rectal adenomas, intramucosal cancers, and superficial submucosal cancers. The purpose of this study is to compare the clinical efficacy between ESD and TAR for non-invasive rectal tumors.

METHODS

Between January 1998 and December 2006, 85 patients with preoperative diagnosis of non-invasive rectal tumors were treated by ESD or TAR. En-bloc resection, local recurrence, complication, procedure time, and hospital stay were evaluated retrospectively using a prospectively-completed database.

RESULTS

Mean resection sizes were 40 mm and 39 mm in diameter for the ESD and TAR groups, respectively. En-bloc resections with a negative resection margin were achieved in 67% (35/52) of the ESD group, which was significantly higher than the 42% (14/33) in the TAR group. Sixty-three lesions were diagnosed as curative resection, histopathologically. There was no local recurrence in the ESD group, but five local recurrences developed in the TAR group. Two rectal perforations, one minor delayed bleeding, and one subcutaneous emphysema in the ESD group were successfully managed conservatively. There were one minor delayed bleeding and two anesthesia-related complications in the TAR group. The ESD group had a shorter hospital stay than the TAR group (4.9 days vs 7 days), but a longer procedure time (131 min vs 63 min).

CONCLUSION

ESD was more effective than TAR in treating non-invasive rectal tumors, with a lower recurrence rate and shorter hospital stay.

Proportion of flat- and depressed-type and laterally spreading tumor among advanced colorectal neoplasia

BACKGROUND & AIMS

Flat- and depressed-type neoplasias along with laterally spreading tumors (LSTs) have been reported in colorectal neoplasias. We estimated the prevalence of flat and depressed types and LSTs along with their proportion among advanced neoplasias in a large average-risk population undergoing screening colonoscopy.

METHODS

This was a cross-sectional study performed at a single, general community institution, with subjects who were 40 to 79 years old, asymptomatic, and who had undergone their first colonoscopy for screening between 2003 and 2009 (n = 4910). Among the neoplasias detected, advanced neoplasias were morphologically classified as the polypoid type, flat and depressed type, or LST. We determined the prevalence and proportion for each type among the advanced neoplasias, with morphologies defined according to the Japanese endoscopic classification.

RESULTS

Advanced neoplasias were detected in 7.9% of men, 4.7% of women, and 6.1% of overall subjects. The polypoid type, the flat and depressed types, and the LSTs accounted for 75.3%, 7.5%, and 17.2% of advanced neoplasia, respectively. There was a high proportion of T1 cancers among the depressed types (40%). Approximately 80% of LSTs were located on the right side of the colon and more than 30% of LSTs showed high-grade dysplasia or T1 cancer.

CONCLUSIONS

Most advanced neoplasias detected were of the polypoid type. LSTs accounted for a considerable proportion among advanced neoplasia and tended to be located on the right side of the colon. The influences of any LSTs need to be taken into consideration for preventing colorectal cancer.

Analysis of K-ras, BRAF, and PIK3CA mutations in laterally-spreading tumors of the colorectum

BACKGROUND AND AIMS

Laterally-spreading tumors (LST) are a newly-recognized category of colorectal neoplasia, and are defined as lesions larger than 10 mm in diameter and extending circumferentially rather than vertically. However, genetic features of this new category of tumors are not fully elucidated. The aim of this study was to evaluate genetic alterations in LST.

METHODS

We examined K-ras, BRAF, and phosphoinositide-3-kinase catalytic-α polypeptide (PIK3CA) mutations in 101 LST, including 68 LST-granular type (LST-G) and 33 LST-non-granular type by direct sequencing. As controls, we examined these gene mutations in 66 protruded colon adenomas (10 mm or larger) and 44 advanced colon cancers.

RESULTS

K-ras, BRAF, and PIK3CA mutations were observed in 59 (58%), zero (0%), and three (3%) LST, respectively. LST-G morphology in the right-sided colon was significantly correlated with the existence of K-ras mutations, whereas a size of 20 mm or larger was the only predictor of mutations in the left-sided colorectum. The frequency of K-ras mutations in LST was particularly marked in the left-sided colorectum compared to protruded adenomas or advanced cancers (LST vs protruded adenomas, P < 0.001; LST vs advanced cancers, P = 0.002), whereas in the right-sided colon, K-ras mutations were equally frequent. PIK3CA mutations were not familiar in either LST (3%) or advanced cancers (9%).

CONCLUSIONS

K-ras mutations were involved in colorectal LST in different manners according to tumor location.

Rectal laterally spreading tumors successfully treated in two steps by endoscopic submucosal dissection and endoscopic mucosal resection

BACKGROUND

Endoscopic submucosal dissection (ESD) is an advanced technique of therapeutic endoscopy alternative to endoscopic mucosal resection (EMR) for superficial gastrointestinal neoplasms >2 cm. ESD allows for the direct dissection of the submucosa and large lesions can be resected en bloc. ESD is not limited by resection size, increases histologically complete resection rates and may reduce the local recurrence. Nevertheless, the technique is time-consuming, technically demanding and associated with a high complication rate. To reduce the risk of complications, different devices and technical advances have been proposed with conflicting results and, still, ESD en bloc resections of huge lesions are associated with increased complications.

CASE PRESENTATION

We successfully used a combined ESD/EMR technique for huge rectal laterally spreading tumors (LSTs). ESD was used for circumferential resection of 2/3 of the lesion followed by piecemeal resection (2-3 pieces) of the central part of the tumour. In all three patients we obtained the complete dissection of the polyp and the complete histological evaluation in absence of complications and recurrence at 6 months' follow up.

CONCLUSIONS

In the treatment of rectal LSTs, the combined treatment - ESD/EMR resection may be considered a suitable therapeutic option, indicated in selected cases as an alternative to surgery, in which the two techniques are neither reliable nor safe separately. However, to confirm our results, larger trials with longer follow up are required together with improvement of the technique and of the technical devices.

Learning curve for endoscopic submucosal dissection of large colorectal tumors

BACKGROUND AND AIM

No studies have previously described the learning curve for colonic endoscopic submucosal dissection (ESD). The aim of the present study was to describe the learning curve for ESD of large colorectal tumors based on a single colonoscopist's experience.

METHODS

ESD was carried out for 120 colorectal tumors in 115 patients (68 males, median age 70 years). All procedures were carried out by a single experienced colonoscopist. The cases were grouped chronologically into three periods: (1st): cases 1-40; (2nd): cases 41-80; and (3rd): cases 81-120.

RESULTS

The learning curve was the changes in proficiency over time. Proficiency was expressed as procedure time per unit area of specimen. In the 1st, 2nd and 3rd periods, the proficiencies were 18.9, 12.6 and 12.9 (min/cm(2) ), respectively. The proficiencies in the 2nd and 3rd periods were significantly shorter than in the 1st period (t-test, P < 0.05). The en-bloc resection rates of the 1st, 2nd and 3rd periods were 92.5% (37/40), 90% (36/40) and 97.5% (39/40), respectively. The en-bloc and R0 resection rates of the 1st, 2nd and 3rd periods were 85% (34/40), 77.5% (31/40) and 92.5% (37/40), respectively. The perforation rates of the 1st, 2nd and 3rd periods were 12.5% (5/40), 5% (2/40) and 5% (2/40), respectively.

CONCLUSION

Based on our analysis of the learning curve, approximately 80 procedures must be carried out to acquire skill with ESD for large colorectal tumors. However, approximately 40 procedures were sufficient to acquire skill in avoiding perforations during the ESD procedure.

Current status in the occurrence of postoperative bleeding, perforation and residual/local recurrence during colonoscopic treatment in Japan

Bleeding, perforation, and residual/local recurrence are the main complications associated with colonoscopic treatment of colorectal tumor. However, current status regarding the average incidence of these complications in Japan is not available. We conducted a questionnaire survey, prepared by the Colorectal Endoscopic Resection Standardization Implementation Working Group, Japanese Society for Cancer of the Colon and Rectum (JSCCR), to clarify the incidence of postoperative bleeding, perforation, and residual/local recurrence associated with colonoscopic treatment. The total incidence of postoperative bleeding was 1.2% and the incidence was 0.26% with hot biopsy, 1.3% with polypectomy, 1.4% with endoscopic mucosal resection (EMR), and 1.7% with endoscopic submucosal dissection (ESD). The total incidence of perforation was 0.74% (0.01% with the hot biopsy, 0.17% with polypectomy, 0.91% with EMR, and 3.3% with ESD). The total incidence of residual/local recurrence was 0.73% (0.007% with hot biopsy, 0.34% with polypectomy, 1.4% with EMR, and 2.3% with ESD). Colonoscopic examination was used as a surveillance method for detecting residual/local recurrence in all hospitals. The surveillance period differed among the hospitals; however, most of the hospitals reported a surveillance period of 3-6 months with mainly transabdominal ultrasonography and computed tomography in combination with the colonoscopic examination.

Macroscopic morphologic subtypes of laterally spreading colorectal tumors showing distinct molecular alterations

Recent advances in colonoscopic techniques have resulted in more frequent detection of superficial-type colorectal tumors, that is, laterally spreading tumors (LSTs), although little is known about the characteristic clinical features and genetic alterations of LSTs. To elucidate the molecular characteristics of LSTs, genetic alterations in the KRAS, BRAF and PIK3CA genes and abnormal expression of the p53, beta-catenin and MYC proteins were analyzed using direct DNA sequencing and immunohistochemistry for 50 protruded-type tumors (Protruded), 35 granular-type LSTs (LST-G) and 19 nongranular-type LSTs (LST-NG). In addition, loss of heterozygosity (LOH) close to the adenomatous polyposis coli (APC) gene (5q21) was examined in these tumors. In univariate analyses, significant differences were noted in the percentages with KRAS mutations (Protruded, LST-G, LST-NG = 30.0%, 54.3%, 21.1%, respectively, p = 0.0156), nuclear accumulation of beta-catenin (Protruded, LST-G, LST-NG = 50.0%, 37.1%, 68.4%, respectively, p = 0.0267), expression of MYC (Protruded, LST-G, LST-NG = 26.0%, 17.1%, 42.1%, respectively, p = 0.0456) and LOH at the APC gene locus (Protruded, LST-G, LST-NG = 22.0%, 20.0%, 47.4%, respectively, p = 0.0302). Multivariate analysis demonstrated that the macroscopic subtype of LST was significantly associated with KRAS mutation (for LST-NG: odds ratio [OR] 0.23, 95% CI 0.06-0.90) and nuclear accumulation of beta-catenin (for LST-NG: OR 4.05, 95% CI 1.11-14.8). Our data revealed that the 2 subtypes of LST have different molecular characteristics, suggesting that 2 or more different molecular mechanisms result in colorectal tumors with a similar growth pattern.

Polyp surveillance

Surveillance after colonic polypectomy is important to detect and remove missed synchronous polyps and cancers and new metachronous polyps or cancers. The authors review methods of surveillance and the risk of recurrent adenomas and provide surveillance recommendations.

Image-enhanced endoscopy is critical in the detection, diagnosis, and treatment of non-polypoid colorectal neoplasms

Colonoscopy, the most sensitive test used to detect advanced adenoma and cancer, has been shown to prevent colorectal cancer (CRC) when combined with polypectomy. CRC remains the third most commonly diagnosed cancer and the second leading cause of cancer death in men and women in the United States. Image-enhanced endoscopy (IEE) is an integral part in the detection, diagnosis, and treatment of non-polypoid colorectal neoplasms. Both the dye-based and equipment-based varieties of IEE are readily available for application in today's practice of colonoscopy. Data are available to support its use, although further studies are needed to simplify the classification of colorectal lesions by the different techniques of equipment-based IEE.

Local recurrence and surveillance after endoscopic resection of large colorectal tumors

Local recurrence rates after endoscopic piecemeal mucosal resection (EPMR) typically range from 10 to 23%. In our previous study, the local recurrence rate after a piecemeal resection was significantly higher than that after an en bloc resection, irrespective of tumor size or macroscopic features. To reduce local recurrence after an EPMR, it is important to carefully note the circumferences of the edge and base of the ulcer. Recently, endoscopic submucosal dissection (ESD) was developed and recognized for its effectiveness in large, complete, en bloc resections and precise pathological assessments. ESD also showed lower local recurrence rates, ranging from 0 to 3% in previous, retrospective studies. However, ESD showed a higher perforation rate and longer procedure times; thus, it is necessary to improve ESD. An appropriate surveillance interval after EPMR was still controversial, and recommendations of some guidelines ranged from 2 to 9 months. In order to determine the appropriate interval, a randomized controlled study is necessary.

A new serrated snare for improved tissue capture during endoscopic snare resection

Endoscopic snare resection of gastrointestinal polyps and neoplasm is a standard procedure in interventional endoscopy. Due to technical and procedural improvements the removal of large sessile polyps can be achieved by endoscopic mucosal resection either in one single specimen or by piecemeal resection. In this experimental study a new snare with special teeth attached to the distal part of the wire loop was evaluated and compared to a conventional snare. Seventy artificial sessile tumors were created in a standardized manner in a porcine ex vivo colon. Thirty-five polyps were resected with the new serrated snare, whilst the other 35 polyps were removed using an identical snare without teeth. The weight measurement of the resected polyps showed that when using the new serrated snare 31% more tissue could be removed with a single snare resection in comparison with the conventional snare without teeth (mean 454 mg vs. 347 mg, +/-202 mg vs. +/-165 mg). The teeth obviously increased the effectiveness of snare resection by avoiding the accidental loss of entrapped tissue from the loop. The new snare hopes to faciliate the removal of flat polyps and to reduce the number of specimens during piecemeal resection to a minimum, allowing a better histopathological assessment.

Cap-assisted endoscopic mucosal resection for colorectal polyps

PURPOSE

Cap-assisted endoscopic mucosal resection has been used to treat superficial esophageal and gastric cancers. Efficacy data in the colon are limited. The aim of the study was to evaluate the safety and efficacy of this technique in the treatment of sessile polyps and lateral spreading tumors in the colorectum.

METHODS

Two-hundred and fifty-five consecutive patients with sessile polyps or lateral spreading tumors >or=20 mm were treated between January 2000 and December 2007.

RESULTS

A total of 146 sessile polyps and 136 lateral spreading tumors were treated with cap-assisted endoscopic mucosal resection. Complications occurred in 22 (8.6%) patients (5.5% in sessile polyps and 10.3% in lateral spreading tumors). Intraprocedural bleeding occurred in 21 (7%) of polypectomies (6% in sessile polyps and 10% in lateral spreading tumors); all were controlled endoscopically. Postcoagulation syndrome occurred in 1 patient with lateral spreading tumor. No perforation occurred. Invasive adenocarcinoma was found in 35 patients, of whom 15 underwent surgery. Endoscopic follow-up in 200 patients with 216 adenomas for a median of 12.1 months showed recurrence in 8 (4%) who were treated with resection and/or ablation.

CONCLUSIONS

Cap-assisted endoscopic mucosal resection is an effective treatment for sessile polyps and lateral spreading tumors. A disadvantage of the technique is that the resection is piecemeal. Close surveillance provides the opportunity for additional tissue ablation, when required, to achieve complete lesion removal.

Complex colon polypectomy

By interrupting the adenoma-carcinoma sequence, endo-scopic polypectomy can prevent the development of colorectal cancer (CRC). Endoscopic polypectomy has, therefore, become an accepted screening and surveillance modality for CRC and has been widely adopted by clinicians, policymakers, and professional organizations as an effective screening tool. Most gastroenterologists are adequately trained to endoscopically excise the majority of polyps found in a routine colonoscopy. However, some polyps, due to their size, location, or configuration, are considered more technically challenging or are associated with an increased risk of complications (such as bleeding or perforation) and, hence, are not routinely resected. These so-called complex polypectomies are the focus of this paper.

Safe procedure in endoscopic submucosal dissection for colorectal tumors focused on preventing complications

Endoscopic submucosal dissection (ESD) is efficient for en bloc resection of large colorectal tumors. However, it has several technical difficulties, because the wall of the colon is thin and due to the winding nature of the colon. The main complications of ESD comprise postoperative perforation and hemorrhage, similar to endoscopic mucosal resection (EMR). In particular, the rate of perforation in ESD is higher than that in EMR. Perforation of the colon can cause fatal peritonitis. Endoscopic clipping is reported to be an efficient therapy for perforation. Most cases with perforation are treated conservatively without urgent surgical intervention. However, the rate of postoperative hemorrhage in ESD is similar to that in EMR. Endoscopic therapy including endoscopic clipping is performed and most of the cases are treated conservatively without blood transfusion. In blood examination, some degree of inflammation is detected after ESD. For the standardization of ESD, it is most important to decrease the rate of perforation. Adopting a safe strategy for ESD and a suitable choice of knife are both important ways of preventing perforation. Moreover, appropriate training and increasing experience can improve the endoscopic technique and can decrease the rate of perforation. In this review, we describe safe procedures in ESD to prevent complications, the complications of ESD and their management.

Large endoscopic mucosal resection for colorectal tumors exceeding 4 cm

AIM: To evaluate the feasibility and the outcome of endoscopic mucosal resection (EMR) for large colorectal tumors exceeding 4 cm (LCRT) undergoing piecemeal resection.

METHODS: From January 2005 to April 2008, 146 digestive tumors larger than 2 cm were removed with the EMR technique in our department. Of these, 34 tumors were larger than 4 cm and piecemeal resection was carried out on 26 colorectal tumors. The mean age of the patients was 71 years. The mean follow-up duration was 12 mo.

RESULTS: LCRTs were located in the rectum, left colon, transverse colon and right colon in 58%, 15%, 4% and 23% of cases, respectively. All were sessile tumors larger than 4 cm with a mean size of 4.9 cm (4-10 cm). According to the Paris classification, 34% of the tumors were type Is, 58% type IIa, 4% type IIb and 4% type IIc. Pathological examination showed tubulous adenoma in 31%, tubulo-villous adenoma in 27%, villous adenoma in 42%, high-grade dysplasia in 38%, in situ carcinoma in 19% of the cases and mucosal carcinoma (m2) in 8% of the cases. The two cases (7.7%) of procedural bleeding that occurred were managed endoscopically and one small perforation was treated with clips. During follow-up, recurrence of the tumor occurred in three patients (12%), three of whom received endoscopic treatment.

CONCLUSION: EMR for tumors larger than 4 cm is a safe and effective procedure that could compete with endoscopic submucosal dissection, despite providing incomplete histological assessment.

Efficacy of an endo-knife with a water-jet function (Flushknife) for endoscopic submucosal dissection of superficial colorectal neoplasms

OBJECTIVES

Endoscopic submucosal dissection (ESD) is currently not a common treatment for colorectal neoplasms because it is time consuming and technically difficult. Flushknife--an electrosurgical endo-knife with a water-jet function--is expected to reduce the difficulty of colorectal ESD. The objective of this study was to investigate the efficacy of a water-jet function for colorectal ESD.

METHODS

This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. A total of 49 patients, with a total of 51 superficial colorectal neoplasms (median tumor size of 30 mm), were enrolled and randomly assigned to undergo ESD using either the Flexknife (electrosurgical endo-knife without a water-jet function) or the Flushknife. Tumors were resected by ESD using each endo-knife. The procedures were conducted by two endoscopists. Operation time was defined as the main outcome measure.

RESULTS

En bloc resection was achieved in 23 out of 26 (88%) lesions in the Flexknife group and in 24 out of 24 (100%) lesions in the Flushknife group. The mean operation time (95% confidence interval) was 87.3 (71.3-103.4) min in the Flexknife group and 61.0 (49.3-72.7) min in the Flushknife group (P=0.02). The Flushknife reduced the number of endoscopic device changes (P=0.001), the number of submucosal injections (P=0.001), and the mean amount of injected hyaluronate sodium (P=0.001) compared with the Flexknife. No severe adverse events were observed in either group.

CONCLUSIONS

Without increasing adverse events, the endo-knife with a water-jet function efficiently reduced the operation time of colorectal ESD in patients with large superficial colorectal neoplasms. (University hospital Medical Information Network Clinical Trials Registry number UMIN000001302).

Natural Orifice Trans-Luminal Endoscopic Surgery in the esophagus

As limited as are the studies regarding peritoneal Natural Orifice Trans-Luminal Endoscopic Surgery, mediastinal transluminal experiments are certainly in their infancy. The authors evaluate the parallel development of minimally invasive thoracic surgery with regard to its counterpart in peritoneal laparoscopy to NOTES. Transesophageal interventions by both endosonographic and direct visualization are examined in the context of minimally invasive surgery and mediastinal NOTES. Techniques of viscerotomy creation, visualization, and closure are examined with particular emphasis on mediastinal structures. The state of current interventions is examined. Finally, current morbidity (including infectious complications) and survival outcomes are examined in those animals that have undergone transesophageal exploration.

Endoscopic treatment for early stage colorectal tumors: the comparison between EMR with small incision, simplified ESD, and ESD using the standard flush knife and the ball tipped flush knife

BACKGROUND

Early stage colorectal tumors can be removed by endoscopic mucosal resection but larger such tumors (20 mm) may require piecemeal resection. Endoscopic submucosal dissection (ESD) using newly developed endo-knives has enabled en-block resection of lesions regardless of size and shape. However ESD for colorectal tumor is technically difficult. Therefore, we performed EMR with small incision (EMR with SI) for more reliable EMR, ESD with snaring (simplified ESD) and ESD using the standard Flush knife and the novel ball tipped Flush knife (Flush knife BT) for easier and safer colorectal ESD.

AIMS

The aims of our study were (1) to compare the treatment results of the following 3 methods (EMR with SI/si-mplified ESD/ESD) for early stage colorectal tumors, and (2) to assess the performance of Flush knife BT in colorectal ESD.

METHODS

We treated 24/44/468 colorectal tumors and examined the clinicopathological features and treatment results such as tumor size, resected specimen size, procedure time, en-bloc resection rate, complication rate. We also treated 58 colorectal tumors (LST-NG:20, LST-G:36, other:2) using standard Flush knife and 80 colorectal tumors (LST-NG:32, LSTG:44, other:2) using Flush knife BT, and examined the clinicopathological features and treatment results mentioned above and also the procedure speed.

RESULT

The median tumor size (mm) (EMR with SI/ simplified EMR/ESD) was 20/17/30 (EMR with SI vs. simplified ESD: p = n.s, simplified ESD vs. ESD: p < 0.0001). The median resected specimen size (mm) was 22.5/26/41 (EMR with SI vs. simplified ESD: p = 0.0018, simplified ESD vs. ESD: p < 0.0001). The procedure time (min.) was 19/27/60 (EMR with SI vs. simplified ESD: p = n.s, simplified ESD vs. ESD: p < 0.0001) The en-block resection rate (%) was 83.3/90.9 /98.9. The complication rate (post-operative bleeding rate/perforation p=n.s). In the treatment results of ESD for LSTs by knives, there was no difference between standard Flush knife and Flush knife BT for clinicopathological features and treatment results (procedure time, complication rate and en bloc R0 resection rate). However, procedure speed (cm2/min.) of LST-G was significantly faster in the Flush knife BT than in standard Flush knife. (standard Flush knife: 0.21 vs. Flush knife BT: 0.27, p = 0.034).

CONCLUSION

EMR with small incision (EMR with SI) and ESD with snaring (simplified ESD) are good option to fill the gap between EMR and ESD in the colorectum, and also considered to become the nice training for the introduction of ESD. Flush knife BT appears to improve procedure speed compared with standard Flush knife, especially for LST-G in colo-rectal ESD.

Clinicopathologic features and endoscopic mucosal resection of laterally spreading tumors: experience from China

BACKGROUND

Laterally spreading tumors (LSTs) are being increasingly reported nowadays in Japan and the western countries with the application of magnification chromoendoscopy. The aim of this study was to analyze the clinicopathologic features of LSTs and to assess the outcome and safety of endoscopic mucosal resection (EMR) in China.

PATIENTS AND METHODS

One hundred nine patients with LSTs who underwent magnification chromoendoscopy were studied retrospectively. Clinicopathological features of 111 LSTs were analyzed. The efficacy and safety of EMR was assessed in 79 LSTs based on the outcome of follow-up colonoscopy and resection-related complications.

RESULTS

A total of 111 LSTs were diagnosed in 109 patients, including 89 (80%) laterally spreading tumor-granular (LST-G) type and 22 (20%) laterally spreading tumor-non-granular (LST-NG) type. There was significant difference in the dominant pit pattern between LST-G type and LST-NG type (p < 0.001). Type IV pit pattern (62%) was the main crypt pattern in LST-G type; whereas, type IIIL (50%) and type V pit pattern (36%) were predominant crypt patterns in LST-NG type. EMR was performed for 103 lesions. Six of the nine lesions with type V(I) pit pattern were completely resected by EMR. Eleven (14%) local recurrent lesions were detected in 79 follow-up lesions and were treated successfully during the follow-up.

CONCLUSIONS

The type of dominant pit pattern was different between LST-G type and LST-NG type. Many LSTs with a type V(I) pit pattern can be completely resected by EMR. EMR technique is a safe and efficacious treatment method for LST.

Evaluation of venous invasion by Elastica van Gieson stain and tumor budding predicts local and distant metastases in patients with T1 stage colorectal cancer

Evaluation of pathologic predictors of metastases in T1 stage colorectal cancer may be difficult with hematoxylin and eosin (HE) staining alone. The aim of this study was to clarify the role of pathologic predictors by using immunohistochemical staining and Elastica van Gieson (EVG) staining. One hundred and twenty-four patients who underwent bowel resection for single T1 stage colorectal cancer from 1990 to 2004 in 1 institution were studied. D2-40, EVG staining, and CAM5.2 were used to detect lymphatic invasion, venous invasion, and tumor budding, respectively. These 3 factors were separately evaluated based on HE staining. Histology was reviewed by 1 pathologist. Lymph node metastases in the surgical specimen were the standard reference, and distant metastases were identified by periodic computed tomography for 2 years or more after surgery. A logistic regression model was applied to analyze risk factors for lymph node metastases and a Cox regression model for distant metastases. In predicting lymph node metastases, univariate analysis demonstrated significance for all predictors except venous invasion by HE staining. Multivariate analysis showed that venous invasion by EVG and tumor budding by HE showed significance as predictors. In predicting distant metastases, univariate analysis showed significance for lymphatic invasion shown by D2-40, tumor budding shown by CAM5.2 and HE, and lymph node metastases. Multivariate analysis showed only venous invasion by EVG stain as being significantly associated with distant metastases (P=0.001). In conclusion, venous invasion evaluated shown by EVG staining is a useful pathologic predictor for metastases in T1 stage colorectal cancer.

Meta-analysis and systematic review of colorectal endoscopic mucosal resection

AIM: To evaluate the proportion of successful complete cure en-bloc resections of large colorectal polyps achieved by endoscopic mucosal resection (EMR).

METHODS: Studies using the EMR technique to resect large colorectal polyps were selected. Successful complete cure en-bloc resection was defined as one piece margin-free polyp resection. Articles were searched for in Medline, Pubmed, and the Cochrane Control Trial Registry, among other sources.

RESULTS: An initial search identified 2620 reference articles, from which 429 relevant articles were selected and reviewed. Data was extracted from 25 studies (n = 5221) which met the inclusion criteria. All the studies used snares to perform EMR. Pooled proportion of en-bloc resections using a random effect model was 62.85% (95% CI: 51.50-73.52). The pooled proportion for complete cure en-bloc resections using a random effect model was 58.66% (95% CI: 47.14-69.71). With higher patient load (> 200 patients), this complete cure en-bloc resection rate improves from 44.19% (95% CI: 24.31-65.09) to 69.17% (95% CI: 51.11-84.61).

CONCLUSION: EMR is an effective technique for the resection of large colorectal polyps and offers an alternative to surgery.

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

Open access endoscopy and screening programs enable detection and removal of an increased number of colon polyps in the early stages of neoplastic transformation. Unfortunately, polyps larger than 3 cm, involving more than one-third of circumference or two haustral folds, or with a flat/depressed morphology are more challenging to remove with standard polypectomy techniques. Endoscopic mucosal resection potentiates the removal, in a minimally invasive way, of certain colonic lesions that would otherwise require surgical or ablative treatment. Because the plane of resection during endoscopic mucosal resection is typically the middle to deep submucosal layer, compared with standard polypectomy, which normally provides resection at a mucosal level, endoscopic mucosal resection offers the advantage of providing en bloc resection specimens for histopathologic analysis. Indications to perform endoscopic mucosal resection are adenoma and small, well-differentiated carcinoma, confined to the mucosa or with minimal invasion to submucosa, and without any invasion to lymphatic channels or vessels. The most frequently reported major complications, such as perforation (0-5%) and bleeding (0.5-6%), may be controlled by endoscopic methods and rarely require surgical treatment. Follow-up postendoscopic mucosal resection is essential because of the risk of neoplastic recurrence.

Therapeutic strategy for colorectal laterally spreading tumor

Most colorectal tumors larger than 20 mm in diameter are called laterally spreading tumors (LST), most of which are adenomatous lesions. Laterally spreading tumors are classified into two types according to their morphology, granular type (LST-G) and non-granular type (LST-NG). Each type has two subtypes. The former consists of a 'homogenous type' and a 'nodular mixed type', while the latter consists of a 'flat elevated (FE) type' and a 'psedodepressed (PD) type'. In LST-G and LST-NG FE types, type V pit pattern with magnification enables the recognition of the carcinomatous or submucosal invasive area. Most of these adenomatous large lesions can be cured by scheduled endoscopic piecemeal mucosal resection (EPMR). However, LST-G with large whole nodular type or type V pit pattern, which cannot be resected en bloc with a snare, is an indication for endoscopic submucosal dissection (ESD). The LST-NG PD has a high frequency of submucosal invasion and the submucosal invasive area cannot be recognized correctly in the pseudodepression with magnification prior to endoscopic treatment. Therefore, en bloc resection with ESD should be applied to LST-NG PD. The therapeutic strategy for choosing between EPMR and ESD for large LST lesions should therefore be determined based on the macroscopic findings of their subtype and pit pattern findings.

The new resources of treatment for early stage colorectal tumors: EMR with small incision and simplified endoscopic submucosal dissection

INTRODUCTION

Early stage colorectal tumors can be removed by endoscopic mucosal resection (EMR) but larger tumors (> or =20 mm) may require piecemeal resection. The development of endoscopic submucosal dissection (ESD) has enabled en-bloc resection of lesions regardless of size and shape. However ESD of colorectal tumor is technically difficult. As the resources, we perform EMR with small incision (EMR with SI) for more reliable EMR, and also ESD with snaring (simplified ESD) for easier and safer ESD. AIM & METHODS: The aim of the study was to retrospectively compare the treatment results of the following 3 methods (EMR with SI/ simplified ESD/ ESD). We treated 24/44/468 colorectal tumors, and examined the tumor size, resected specimen size, procedure time, en-bloc resection rate, complication rate.

RESULT

The median tumor size (mm) (EMR with SI/simplified EMR/ESD) was 20/17/30 (EMR with SI vs simplified ESD: P = n.s, simplified ESD vs ESD: P < 0.0001). The median resected specimen size (mm) was 22.5/26/41 (EMR with SI vs simplified ESD: P = 0.0018, simplified ESD vs ESD: P < 0.0001). The procedure time (min.) was 19/27/60 (EMR with SI vs simplified ESD: P = n.s, simplified ESD vs ESD: P < 0.0001) The en-bloc resection rate (%) was 83.3/90.9/98.9. The complication rate (post-operative bleeding rate/perforation rate) was 0/0, 2.3/4.5, 1.5/1.5 (simplified ESD vs ESD: P = n.s).

CONCLUSION

Endoscopic mucosal resection with small incision (EMR with SI) and ESD with snaring (simplified ESD) are a good option to fill the differences between conventional EMR and ESD, and also considered to become nice steps to the introduction of ESD.

Chromoendoscopy

Chromoendoscopy involves the use of stains or dyes during endoscopy to improve the visualization and characterization of the gastrointestinal mucosa. Its main clinical application is the detection of dysplasia or early cancer of the gastrointestinal tract in individuals with pre-malignant conditions or hereditary and environmental factors that predispose them to cancer. The utility of chromoendoscopy has been mostly studied in squamous cell carcinoma of the esophagus, Barrett's esophagus, gastric cancer, colorectal polyps, and chronic ulcerative colitis. Although chromoendoscopy has been shown to be feasible and safe, several limitations have prevented its widespread use in endoscopy. Despite this, chromoendoscopy remains a useful adjunct to standard white light endoscopy in the visualization of mucosal lesions, which may potentially improve tissue diagnosis and impact patient care.

Transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND-study)

Background

Recent non-randomized studies suggest that extended endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM). If equally effective, EMR might be a more cost-effective approach as this strategy does not require expensive equipment, general anesthesia and hospital admission. Furthermore, EMR appears to be associated with fewer complications.

The aim of this study is to compare the cost-effectiveness and cost-utility of TEM and EMR for the resection of large rectal adenomas.

Methods/design

Multicenter randomized trial among 15 hospitals in the Netherlands. Patients with a rectal adenoma ≥ 3 cm, located between 1–15 cm ab ano, will be randomized to a TEM- or EMR-treatment strategy. For TEM, patients will be treated under general anesthesia, adenomas will be dissected en-bloc by a full-thickness excision, and patients will be admitted to the hospital. For EMR, no or conscious sedation is used, lesions will be resected through the submucosal plane in a piecemeal fashion, and patients will be discharged from the hospital. Residual adenoma that is visible during the first surveillance endoscopy at 3 months will be removed endoscopically in both treatment strategies and is considered as part of the primary treatment.

Primary outcome measure is the proportion of patients with recurrence after 3 months. Secondary outcome measures are: 2) number of days not spent in hospital from initial treatment until 2 years afterwards; 3) major and minor morbidity; 4) disease specific and general quality of life; 5) anorectal function; 6) health care utilization and costs. A cost-effectiveness and cost-utility analysis of EMR against TEM for large rectal adenomas will be performed from a societal perspective with respectively the costs per recurrence free patient and the cost per quality adjusted life year as outcome measures.

Based on comparable recurrence rates for TEM and EMR of 3.3% and considering an upper-limit of 10% for EMR to be non-inferior (beta-error 0.2 and one-sided alpha-error 0.05), 89 patients are needed per group.

Discussion

The TREND study is the first randomized trial evaluating whether TEM or EMR is more cost-effective for the treatment of large rectal adenomas.

Trial registration number

(trialregister.nl) NTR1422

Colorectal endoscopic submucosal dissection: present status and future perspective, including its differentiation from endoscopic mucosal resection

Endoscopic submucosal dissection (ESD) allows en bloc resection of a lesion, irrespective of the size of the lesion. ESD has been established as a standard method for the endoscopic ablation of malignant tumors in the upper gastrointestinal (GI) tract in Japan. Although the use of ESD for colorectal lesions has been studied via clinical research, ESD is not yet established as a standard therapeutic method for colorectal lesions because colorectal carcinoma has unique pathological, organ specific characteristics that differ radically from those of the esophagus and stomach, and scope handling and control is more difficult in the colorectum than in the upper GI tract. Depending on the efficacy of endoscopic mucosal resection (EMR) and the clinicopathological characteristics of the colorectal tumor, the proposed indications for colorectal ESD are as follows: (1) lesions difficult to remove en bloc with a snare EMR, such as nongranular laterally spreading tumors (particularly the pseudo depressed type), lesions showing a type VI: pit pattern, and large lesions of the protruded type suspected to be carcinoma; (2) lesions with fibrosis due to biopsy or peristasis; (3) sporadic localized lesions in chronic inflammation such as ulcerative colitis; and (4) local residual carcinoma after EMR. Colorectal ESD is currently in the development stage, and a standard protocol will be available in the near future. We hope that colorectal tumors will be efficiently treated by a treatment method appropriately selected from among EMR, ESD, and surgical resection after precise preoperative diagnosis based on techniques such as magnifying colonoscopy.

Salvage endoscopic submucosal dissection for residual or local recurrent intraepithelial neoplasia in the colorectum: a prospective analysis

OBJECTIVE

A prospective technical feasibility study of cap assisted ESD for 'curative intent' in patients with residual or local neoplastic recurrence following EMR. Primary end points were second stage R0 resection rate, safety and recurrence.

METHOD

Salvage ESD was performed using the Olympus GIF-XQ240 gastroscope and KD-630L insulation tipped knife. Thirty-day mortality, re-admission rates, complications and histological resection status were collected prospectively up to 9 months following index resection.

RESULTS

Thirty patients met eligibility criteria. Index R0 resection was achieved in 25/30 (83%) lesions. One patient underwent surgical excision with a second receiving a curative second stage dissection. Ninety-six per cent (29/30) patients were discharged within 24 h of the procedure with a 0% 30-day mortality and re-admission rate. Bleeding occurred in 5/30 (16%) treated successfully with endoluminal haemostasis. There were no perforations. Overall 'cure' rates at short-term follow-up [median 6/12 (range; 3-18)] was 96%.

CONCLUSION

This novel application of ESD for first line 'salvage' therapy in treating residual or locally recurrent neoplastic disease may be a safe, minimally invasive and cost effective alternative to direct surgical resection in a select patient cohort.

Future expectations in digestive endoscopy: competition with other novel imaging techniques

Digestive endoscopy has been evolving from primary diagnostic to extensive therapeutic modalities in the management of gastrointestinal diseases. The present endoscopic imaging includes (A) standard endoscopy alone and /or with adjunct technologies such as point enhancement, e.g. confocal endomicroscopy and field enhancement technologies such as chromoendoscopy, NBI and FICE and (B) endoscopic ultrasound. Other novel imaging technologies including virtual colonoscopy or CT/MR colonography, CT or MRI enterography and capsule endoscopy have also been developed. This article reviews the diagnostic and therapeutic role of digestive endoscopy and future directions of digestive endoscopy are discussed. Digestive endoscopy is also compared with emerging novel imaging techniques in gastrointestinal diseases such as capsule endoscopy and CT colonography. The fact that digestive endoscopy has become a multidisciplinary specialty combining advances in all fields (radiology, bioengineering, surgery and gastroenterology) is highlighted.