Our perspective on endoscopic resection for colorectal neoplasms

Substratifying the risk of covert malignancy in significant rectal polyps: Outcomes from a specialist multidisciplinary team (MDT)

AIM

A treatment strategy for patients with a significant polyp or early colon cancer (SPECC) of the rectum presents a challenge due to the significant rate of covert malignancy and lack of standardized assessment. For this reason, NICE recommends multidisciplinary meetings to improve outcomes. The primary aim of the present study was to report the performance of our specialist early rectal cancer (SERC) multidisciplinary team (MDT) in correctly substratifying the risk of cancer and to discuss the limitations of staging investigations in those patients with "poor outcomes".

METHOD

This was a retrospective review of patients referred to our SERC MDT from 2014 to 2019. Lesions were assigned by the MDT to three pre-resection categories (low, intermediate, high) according to the risk of covert malignancy. Resection method and final histology were compared to the pre-resection categories.

RESULTS

Of 350 SPECC lesions, 174 were assessed as low-risk, 108 intermediate-risk and 68 high-risk. The cancer incidence was 4.8%, 8.3% and 53%, respectively (15.5% overall). Eight lesions were categorized as low-risk but following piecemeal resection were found to be malignant. Five lesions, three of which were categorized as high-risk, were ultimately benign following conventional surgery. One pT1sm1 cancer, removed by anterior resection, may have been treated by local excision.

CONCLUSION

A total of 83% of malignant polyps were triaged to an en bloc resection technique and surgical resection avoided for nearly all benign lesions. However, 12 patients from this cohort were deemed to have a poor outcome because of miscategorization. Further comparative research is needed to establish the optimum strategy for rectal SPECC lesion assessment.

ORIGINALITY STATEMENT

There is currently no consensus for staging significant polyps of the rectum. This paper reports the effectiveness of a specialist early rectal cancer MDT to correctly risk-stratify significant rectal polyps. It underscores the importance of accurate categorization for treatment decision-making, while acknowledging the limitations of current staging modalities.

Novel technique for endoscopic en bloc resection (EMR+) - Evaluation in a porcine model

BACKGROUND

Endoscopic en bloc resection of larger polyps is relevant because risk of advanced neoplasia or malignancy correlates with tumor size. Recurrence rates after piecemeal endoscopic mucosal resection (EMR) are high and endoscopic submucosal dissection (ESD) is associated with higher complication rates in the western world.

AIM

To develop a modified endoscopic en bloc resection technique using an external additional working channel and novel agent for submucosal injection.

METHODS

EMR+ was considered as modified grasp and snare technique. For simultaneous use of a grasping and cutting device a novel additional working channel was used (AWC^®, Ovesco Endoscopy, Tübingen, Germany). AWC^® is installed on the outer surface of the endoscope, covered with a plastic sleeve and designed for single use. For submucosal injection a new agent consisting of poloxamers was used (LiftUp^®, Ovesco Endoscopy, Tübingen, Germany). The agent is liquid at room temperature and forms a stable and permanent gel cushion after injection. Safety of LiftUp^® has been shown in a pre-clinical study in domestic pigs. LiftUp^® is commercially not yet available but approval is expected in early 2019. EMR+ was first developed ex vivo (explanted pig stomach) and subsequently evaluated in vivo (stomach, porcine model, 3 domestic pigs). Main outcome measurements were: Procedure time, macroscopic en bloc resection and adverse events.

RESULTS

Concept of EMR+ was first developed ex vivo (explanted pig stomach). Ex vivo, 22 resections were performed after technique was established. Median procedure time (measured from begin of injection to extraction of resection specimen) was 7 min (range 5-11, SD 1.68) and median size of resection specimens was 30 mm × 26 mm × 11 mm ex vivo. Subsequently 13 resections were performed in vivo (stomach, porcine model, 3 domestic pigs). In vivo, median procedure time (measured from begin of injection to extraction of resection specimen) was 5 min (range 3-12, SD 2.72) and median size of resection specimens was 35 mm × 35 mm × 11 mm. In vivo, resection was macroscopic complete in 92.3%, major adverse events were not observed. In one case (7.7%) minor periprocedural bleeding was observed and managed by coagulation.

CONCLUSION

EMR+ appeared to be effective and safe and was easy and fast to perform in the porcine model. EMR+ needs to be further evaluated clinically in comparative trials.

Endoscopic treatment outcomes of laterally spreading tumors with a skirt (with video)

BACKGROUND AND AIMS

A "skirt" is a slightly elevated flat lesion with wide pits occasionally observed at the margin of laterally spreading tumors (LSTs). However, the endoscopic treatment outcomes of LSTs with skirts have not been clarified. The aim of this study was to evaluate the endoscopic treatment outcomes of LSTs with skirts.

METHODS

Between February 2006 and March 2014, 996 LSTs were retrospectively examined to assess the clinicopathologic characteristics, procedure time, en bloc resection rate, R0 resection rate, adverse events, and local recurrence rate of endoscopic submucosal dissection (ESD) and of endoscopic resection.

RESULTS

Endoscopic treatment was performed in 35 cases of LSTs with skirts (ratio of ESD to endoscopic piecemeal mucosal resection [EPMR], 32:3) and 961 cases of LSTs without skirts (ratio of ESD to EMR to EPMR to polypectomy, 381:275:114:191). LSTs with a skirt were associated with a significantly higher recurrence rate (P < .01). In both ESD and EPMR, LSTs with a skirt were associated with a higher recurrence rate when compared with LSTs without a skirt (odds ratio, 12.7; P = .032, and odds ratio, 12.3; P = .061, respectively). Multivariate analysis demonstrated that the presence of the skirt and piecemeal resection were significant predictors of local recurrence.

CONCLUSIONS

LSTs with skirts had a significantly higher local recurrence rate after endoscopic treatment compared with LSTs without skirts, especially after EPMR. Therefore, ESD should be recommended as an endoscopic treatment for LSTs with skirts to minimize local recurrence.

Endoscopic mucosal resection and endoscopic submucosal dissection for colorectal lesions: A systematic review

AIM

To assess the efficacy and safety of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for the treatment of colorectal lesions.

METHODS

A literature search was conducted from January 2000 to May 2015. The main outcomes were: recurrence after "en bloc" and "piecemeal" resection; procedure related adverse events; the EMR endoscopic success rate and the completely eradicated resection rate (R0) after ESD.

RESULTS

A total of 66 studies were included in the analysis. The total number of lesions was 17950 (EMR: 11.873; ESD: 6077). Recurrence rate was higher in the EMR than ESD group (765/7303l vs. 50/3910 OR 8.19, 95% CI 6.2-10.9 p<0.0001). EMR-en bloc resection was achieved in 6793/10803 lesions (62.8%) while ESD-en bloc resection was obtained in 5500/6077 lesions (90.5%) (OR 0.18, p<0.0001, 95% CI 0.16-0.2). Perforation occurred more frequently in ESD than in EMR group (p<0.0001, OR 0.19, 95% CI 0.15-0.24).

CONCLUSIONS

Endoscopic resection of large colorectal lesions is safe and effective. Compared with EMR, ESD results in higher "en bloc" resection rate and lower local recurrence rate, however ESD has high procedure-related complication rates.

Endoscopic mucosal resection (EMR) versus endoscopic submucosal dissection (ESD) for resection of large distal non-pedunculated colorectal adenomas (MATILDA-trial): rationale and design of a multicenter randomized clinical trial

Background

Endoscopic mucosal resection (EMR) is currently the most used technique for resection of large distal colorectal polyps. However, in large lesions EMR can often only be performed in a piecemeal fashion resulting in relatively low radical (R0)-resection rates and high recurrence rates. Endoscopic submucosal dissection (ESD) is a newer procedure that is more difficult resulting in a longer procedural time, but is promising due to the high en-bloc resection rates and the very low recurrence rates. We aim to evaluate the (cost-)effectiveness of ESD against EMR on both short (i.e. 6 months) and long-term (i.e. 36 months). We hypothesize that in the short-run ESD is more time consuming resulting in higher healthcare costs, but is (cost-) effective on the long-term due to lower patients burden, a higher number of R0-resections and lower recurrence rates with less need for repeated procedures.

Methods

This is a multicenter randomized clinical trial in patients with a non-pedunculated polyp larger than 20 mm in the rectum, sigmoid, or descending colon suspected to be an adenoma by means of endoscopic assessment. Primary endpoint is recurrence rate at follow-up colonoscopy at 6 months. Secondary endpoints are R0-resection rate, perceived burden and quality of life, healthcare resources utilization and costs, surgical referral rate, complication rate and recurrence rate at 36 months. Quality-adjusted-life-year (QALY) will be estimated taking an area under the curve approach and using EQ-5D-indexes. Healthcare costs will be calculated by multiplying used healthcare services with unit prices. The cost-effectiveness of ESD against EMR will be expressed as incremental cost-effectiveness ratios (ICER) showing additional costs per recurrence free patient and as ICER showing additional costs per QALY.

Discussion

If this trial confirms ESD to be favorable on the long-term, the burden of extra colonoscopies and repeated procedures can be prevented for future patients.

Trial registration

NCT02657044 (Clinicaltrials.gov), registered January 8, 2016.

A long-term follow-up study on the prognosis of endoscopic submucosal dissection for colorectal laterally spreading tumors

BACKGROUND AND AIMS

Colorectal laterally spreading tumors (LSTs) are divided into homogeneous (LST-G-H), nodular mixed (LST-G-M), flat elevated (LST-NG-F), and pseudodepressed (LST-NG-PD) subtypes. We hypothesized that based on the rates of advanced histology, the recurrence rates of the LST-NG-PD and LST-G-M groups may be higher than those of the other subgroups.

METHODS

Endoscopic submucosal dissection (ESD) was performed in 156 patients with a total of 177 LSTs. The clinicopathological features and long-term prognosis of ESD according to specific subtype were investigated.

RESULTS

LSTs were most commonly found in the rectum, and the highest percentage of rectal lesions was observed in the LST-G-M group (71.1% vs overall 55.4%, P = .032). The LST-G-M lesions were larger (60 ± 22 mm vs 40 ± 33 mm, P = .034) than the LST-G-H lesions. The LST-G-M group also demonstrated more high-grade intraepithelial neoplasias (32.2% vs 10.8%, P = .003) and submucosal carcinomas (13.6% vs 1.5%, P = .010) compared with the LST-G-H group. The LST-NG-PD group exhibited the highest incidence of submucosally invasive cancer (16.7%). The overall perforation rate was 2.3%. The perforation rate in the LST-NG group was higher than that in the LST-G group (5.7% vs 0.8%, P = .047). All recurrences (7.7%) were found by colonoscopy without any detection of cancers, and no difference was found among the subtypes.

CONCLUSIONS

No significant differences were observed among subgroups with 44.4 ± 16.3 months of follow-up. Considering that all recurrences were discovered by colonoscopy and most could be cured by repeated ESD, the LSTs of all subgroups require more intensive follow-up compared with smaller adenomatous lesions.

Endoscopic surgery - exploring the modalities

The adoption of endoscopic surgery continues to expand in clinical situations with the recent natural orifice transluminal endoscopic surgery technique enabling abdominal organ resection to be performed without necessitating any skin incision. In recent years, the development of numerous devices and platforms have allowed for such procedures to be carried out in a safer and more efficient manner, and in some ways to better simulate triangulation and surgical tasks (e.g., suturing and dissection). Furthermore, new novel techniques such as submucosal tunneling, endoscopic full-thickness resection and hybrid endo-laparoscopic approaches have further widened its use in more advanced diseases. Nevertheless, many of these new innovations are still at their pre-clinical stage. This review focuses on the various innovations in endoscopic surgery, with emphasis on devices and techniques that are currently in human use.

Histological assessment of intra- and inter-institutional reliabilities in detection of desmoplastic reaction in biopsy specimens of early colorectal carcinomas

We previously reported a relationship between depth of submucosal invasion of early colorectal carcinomas and desmoplastic reaction (DR). However, poor inter-observer agreement on the histopathological diagnosis of DR in biopsy specimens with hematoxylin and eosin (H&E) staining has been the major critique of this tool. In this study, reproducibility of the histopathological diagnosis of DR was evaluated. Furthermore, we investigated the possible improvement of the reproducibility after education about histological characteristics and tried to identify histological characteristics that are most important in the recognition of DR. A total of 34 H&E stained slides were included in this study and analyzed by three pathologists. Slides were reviewed before and after education about histological characteristics of DR. Kappa statistics were used to compare the inter-observer variability. We investigated the relationship between DR and histopathological factor. The inter-observer agreement during the first session varied between 0.30 and 0.63, which improved during the second session toward an agreement between 0.58 and 0.71. Myofibroblast proliferation associated with cancer invasion was found to be the most useful in the diagnosis of DR. In conclusion, the correct detection of myofibroblasts may facilitate the standardization of diagnosis of DR.

Comparison of clinical outcomes among different endoscopic resection methods for treating colorectal neoplasia

BACKGROUND/AIM

Endoscopic treatments of colorectal neoplasms have yet to be standardized. This study aimed to compare efficacy and tolerability of different endoscopic resection methods for colorectal epithelial tumors.

METHODS

Patients with non-pedunculated colorectal tumors undergoing endoscopic treatments were consecutively enrolled, and their medical records were reviewed retrospectively. The resection methods were classified into three groups: endoscopic mucosal resection with circumferential precutting (EMR-P), endoscopic submucosal dissection with snaring (ESD-S), and endoscopic submucosal dissection alone (ESD). We compared en bloc resection, pathological complete resection, and complications associated with these methods.

RESULTS

Overall, 206 lesions from 203 patients were included in the study (mean size 25.2 ± 10.1 mm). The number of lesions treated with EMR-P, ESD-S, and ESD was 91 (44.2 %), 57 (27.7 %), and 58 (28.2 %), respectively. There was a significant difference in both the en bloc resection rates (EMR-P, 61.5 %; ESD-S, 64.9 %; ESD, 96.6 %; p = 0.001) and complete resection rates (EMR-P, 51.6 %; ESD-S, 54.4 %; ESD, 75.9 %; p = 0.009). Bleeding and perforation were less frequently observed in the EMR-P group. In the subgroup-analysis of lesions less than 20 mm, however, these differences were not observed.

CONCLUSIONS

All endoscopic resection methods, including EMR-P, ESD-S, and ESD, were effective and safe for the treatment of colorectal neoplasms. Technically demanding ESD with high en bloc and complete resection rate should be reserved for the suspicious cancer lesion, which requires the precise histological evaluation. EMR-P with good feasibility can be considered an alternative to ESD for the lesions less than 20 mm.

Colorectal endoscopic submucosal dissection: is it suitable in western countries?

Endoscopic submucosal dissection (ESD) represents a significant advance in therapeutic endoscopy with the major advantage being the ability to achieve a higher en bloc resection rate for early stage lesions. Western endoscopists infrequently perform colorectal ESD (CR-ESD) because of the greater technical difficulty involved, longer procedure times, and increased risk of perforation. Specialized training and sufficient clinical experience are necessary to successfully perform ESDs, but a systematic education and training program has still not been established in Japan or elsewhere in the world. Experts generally acknowledge that the stomach is the first organ in which endoscopists should begin performing ESDs. The incidence and detection rates for early stage gastric cancer are significantly higher in Japan than in western countries, so Japanese endoscopists have a greater opportunity to perform gastric ESDs than their western counterparts. It is logical to ask, therefore, whether CR-ESD can be effectively applied in western countries. Based on a review of the relevant literature and our practical perspective, we have focused on the progress made in performing CR-ESD, its indications, training methods, and learning curve. Use of animal gastric and colon models is strongly recommended along with accumulating the necessary experience from the rectum to the colon on a step-by-step basis. It is reasonable to assume that an increasing number of CR-ESDs will be performed by western endoscopists in the foreseeable future given the continuing development of new techniques, and the refinement of instruments and other technologically advanced devices together with the creation of even more effective submucosal injection agents.

Technique of endoscopic biopsy of islet allografts transplanted into the gastric submucosal space in pigs

Currently, islet cells are transplanted into the liver via portal vein infusion. One disadvantage of this approach is that it is not possible to adequately biopsy the islets in the liver to assess for rejection. Islet transplantation (Tx) into the gastric submucosal space (GSMS) can be performed endoscopically and has the potential advantage of histological evaluation by endoscopic biopsy. The aim of this study was to determine whether a representative allograft sample could be obtained endoscopically. We performed islet Tx into the GSMS in nonimmunosuppressed pigs using simple endoscopic submucosal injection. Islets were transplanted at four sites. Endoscopic ultrasonography and biopsy of the transplanted islets at two sites by modified endoscopic submucosal dissection were carried out successfully in all pigs 5 days after islet Tx. Tissue obtained at both biopsy and necropsy (including full-thickness sections of the gastric wall around the sites of the remaining islets and biopsies) were examined by histology and immunohistochemistry to confirm the presence of the islet grafts and any features of rejection. Representative allograft sampling was successfully obtained from all biopsy sites. All biopsies included islets with insulin-positive staining. There was significant CD3(+) and CD68(+) cell infiltration in the islet masses obtained at biopsy and from sections taken at necropsy, with similar histopathological features. Endoscopic biopsy of islet allografts in the GSMS is feasible, provides accurate histopathological data, and would provide a significant advance if translated into clinical practice.

Colorectal lateral spreading tumor subtypes: clinicopathology and outcome of endoscopic submucosal dissection

PURPOSE

This study aims to investigate the clinicopathological features of specific subtypes of laterally spreading tumor (LST) and assessed the outcome of endoscopic submucosal dissection (ESD) based upon subdifferentiation status.

METHODS

A total of 137 LSTs were present in 135 patients; 96 were granular and 41 exhibited a nongranular pattern. Granular LSTs, subdivided into homogeneous and nodular mixed, and nongranular LSTs, subdivided into flat-elevated and pseudodepressed, were retrospectively evaluated with respect to clinicopathological features and results of ESD (en bloc R0 curative resection, procedure time, complication, and recurrence rate) according to specific subtype.

RESULTS

The distribution of high-grade intraepithelial neoplasia and submucosal carcinomas was more prominent among granular nodular mixed tumors than among granular homogeneous tumors (P = 0.007), whereas there was no significant difference between nongranular pseudodepressed tumors and flat-elevated tumors. The frequency of en bloc R0 curative resection did not differ significantly among specific subtypes. For nodular mixed and pseudodepressed lesions, the median tumor size was significantly larger (P < 0.001 for each) and mean procedure time was also longer (P < 0.05 for each) than for the other two subtypes. All complications, which included three perforations, five episodes of postoperative bleeding, and one recurrence, occurred in granular nodular mixed and nongranular pseudodepressed tumors.

CONCLUSION

The risk of cancer varies with the subtypes of LSTs. ESD is an effective treatment for LSTs, however ESD is more technically demanding and carries more complications in pseudodepressed and granular mixed subtypes.

Cap-assisted EMR of large, sporadic, nonampullary duodenal polyps

BACKGROUND

EMR is an effective alternative to surgery for the removal of nonampullary duodenal polyps (NADPs). Cap-assisted EMR (EMR-C) has been rarely performed in the duodenum because of the risk of perforation.

OBJECTIVE

To evaluate the safety and effectiveness of EMR-C for the removal of large (≥ 15 mm) NADPs.

DESIGN

Retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

Between 2000 and 2010, 26 consecutive patients with sporadic NADPs underwent EMR-C.

INTERVENTION

EMR with the cap technique.

MAIN OUTCOME MEASUREMENTS

Complete eradication of polyps, complications, and recurrence.

RESULTS

A total of 14 sessile polyps (53.8%), 7 lateral spreading type nongranular tumors (26.9%), and 5 lateral spreading type granular tumors (19.2%) were treated. The median size of lesions was 15 mm. Five lesions involved one-half of the luminal circumference. Post-EMR histologic assessment showed low-grade dysplasia in 5 patients (19.2%) and high-grade dysplasia in 18 patients (69.2%). Three patients (11.5%) had well-differentiated endocrine tumors. Complete eradication was obtained in 25 of 26 (96%) patients. No perforations occurred. Three cases of intraprocedural bleeding were managed endoscopically. Median follow-up was 6 years (range 1-10 years). Residual adenomatous tissue was observed in 3 patients in lesions of 50 mm. In one of these cases, an adenocarcinoma occurred after 8 months, which was managed surgically.

LIMITATIONS

Retrospective design, single center.

CONCLUSION

This study supports the efficacy and safety of EMR-C for removing NADPs. Regular follow-up is mandatory because of the high risk of residual or recurrent adenomatous tissue and even cancer.

Desmoplastic reaction in biopsy specimens of early colorectal cancer: a Japanese prospective multicenter study

We previously reported that detection of desmoplastic reaction (DR) in pretreatment biopsy specimens was useful for predicting the depth of submucosal invasion (SM depth) in nonpedunculated early colorectal cancers (ECRCs) in a retrospective study. Here, we performed a prospective multicenter study for verification of our previous findings. Subjects were diagnosed with ECRC by endoscopy, and with adenocarcinoma from the biopsy specimens. Eleven institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum participated in this collaborative study. A total of 112 patients with ECRC were enrolled. For nonpedunculated ECRCs, presence of DR was significantly correlated with SM depth. The sensitivity and specificity of detection of DR for prediction of pSM2 (tumor invasion ≥1000 µm) in nonpedunculated ECRCs were 68.6% and 92.0%, respectively. Evaluation of DR in pretreatment biopsy specimens may be useful for the clinicopathological diagnosis of colorectal carcinoma with massive invasion into the submucosal layer.

A technical review of flexible endoscopic multitasking platforms

BACKGROUND

Further development of advanced therapeutic endoscopic techniques and natural orifice translumenal endoscopic surgery (NOTES) requires a powerful flexible endoscopic multitasking platform.

METHODS

Medline search was performed to identify literature relating to flexible endoscopic multitasking platform from year 2004-2011 using keywords: Flexible endoscopic multitasking platform, NOTES, Instrumentation, Endoscopic robotic surgery, and specific names of various endoscopic multitasking platforms. Key articles from articles references were reviewed.

RESULTS

Flexible multitasking platforms can be classified as either mechanical or robotic. Purely mechanical systems include the dual channel endoscope (DCE) (Olympus), R-Scope (Olympus), the EndoSamurai (Olympus), the ANUBIScope (Karl-Storz), Incisionless Operating Platform (IOP) (USGI), and DDES system (Boston Scientific). Robotic systems include the MASTER system (Nanyang University, Singapore) and the Viacath (Hansen Medical). The DCE, the R-Scope, the EndoSamurai and the ANUBIScope have integrated visual function and instrument manipulation function. The IOP and DDES systems rely on the conventional flexible endoscope for visualization, and instrument manipulation is integrated through the use of a flexible, often lockable, multichannel access device. The advantage of the access device concept is that it allows optics and instrument dissociation. Due to the anatomical constrains of the pharynx, systems are designed to have a diameter of less than 20 mm. All systems are controlled by traction cable system actuated either by hand or by robotic machinery. In a flexible system, this method of actuation inevitably leads to significant hysteresis. This problem will be accentuated with a long endoscope such as that required in performing colonic procedures. Systems often require multiple operators. To date, the DCE, the R-Scope, the IOP, and the Viacath system have data published relating to their application in human.

CONCLUSION

Alternative forms of instrument actuation, camera control and master console ergonomics should be explored to improve instrument precision, sphere of action, size and minimize assistance required.

Prognostic significance of tumor budding in gastrointestinal tumors

Tumor budding describes the presence of single tumor cells or small tumor cell clusters at the invasion front of carcinomas. It is currently thought to be the result of epithelial-mesenchymal transformation. Tumor budding can be appreciated histologically during routine evaluation of malignant polyps or surgical specimens of malignant tumors. Many studies have been published assessing cancers in all locations from the esophagus to the rectum, almost always reporting similar results. This seems especially remarkable as a generally accepted definition of how budding must be evaluated is still lacking. Regardless of the location, tumor budding generally is associated with nodal metastases and aggressive behavior, and it is mostly independent from other adverse factors. While the prognostic value of tumor budding is evident, especially in stage II colorectal cancers, it still has no therapeutic implications. This is owing to the heterogeneity of the performed studies and the lack of oncological studies, which are urgently needed.