Colorectal endoscopic submucosal dissection in Japan and Western countries

Various studies by Japanese endoscopists have demonstrated that colorectal endoscopic submucosal dissection (ESD) can overcome technical limitations of the endoscopic mucosal resection (EMR) technique such as piecemeal resection for flat lesions larger than 20 mm, resection of lesions involving the dentate line or the ileocecal valve and lesions with the non-lifting sign, and achieve higher en bloc resection rate. However, it is infrequently performed in Western countries in comparison with Japan, despite the advantages explained above. There are some differences between Japan and Western countries in environments and clinical settings for performing ESD in the colorectum. Endoscopists who perform colorectal ESD around the world are considering that refinements in ESD techniques, devices and training will be necessary to further reduce a higher risk of complications and longer procedure times before adoption of ESD can be recommended on a widespread international scale.     

Beyond the snare: technically accessible large en bloc colonic resection in the West: an animal study

Background: Endoscopic submucosal dissection (ESD) and circumferential submucosal incision endoscopic mucosal resection (CSI‐EMR) are techniques for en bloc excision of large sessile colonic lesions. Our aims were to compare the efficacy, safety and learning curve of colonic hybrid knife (HK) ESD versus CSI‐EMR for en bloc excision of 50 mm diameter hemi‐circumferential artificial lesions in a porcine model. Patients and Methods: Two separate 50 mm diameter areas of normal recto‐sigmoid mucosa were marked out in each of ten pigs. One was excised with HK‐ESD using succinylated gelatin (SG) submucosal injection. The other was isolated with CSI with the Insulated Tip Knife 2 followed by SG submucosal injection then EMR with a large snare. Euthanasia and colectomy was performed at 72 h followed by blinded histopathology assessment. Results: En bloc excision rates were: HK‐ESD 100% versus CSI‐EMR 20% (P = 0.008). The mean number of resections per lesion was HK‐ESD 1 versus CSI‐EMR 3 (P = 0.001). The mean dimensions of the largest specimen per technique were HK‐ESD 63 × 54 mm versus CSI‐EMR 49 × 41 mm (P = 0.005). Procedure duration mean was HK‐ESD 54 min versus CSI‐EMR 22 min (P < 0.001). When procedure duration was adjusted for the size of the resected en bloc specimen, a statistically significant and accelerated learning effect was noted for HK‐ESD (r = ?0.83, P = 0.003). There were no perforations and no significant bleeding. Conclusions: HK‐ESD with SG submucosal injection is superior to CSI‐EMR for en bloc excision of 50 mm diameter lesions in a porcine model. The technique is rapidly learnt. This novel approach may lower the barrier to colonic ESD for Western endoscopists.     

Endoscopic submucosal dissection in the West: Current status and future directions

Endoscopic submucosal dissection (ESD) was first conceptually described almost 30 years ago in Japan and is now widely practiced throughout East Asia. ESD expands the boundaries of endoscopic resection (ER) by allowing en bloc resection of large early neoplastic lesions within the gastrointestinal tract (GIT). This offers advantages over other ER techniques by facilitating definitive histological staging and curative treatment of early cancer in selected cases. Indeed, the experience of ESD in Eastern countries is significant, and excellent outcomes from high‐volume centers are reported. The potential benefits of ESD are recognized by Western endoscopists, but its adoption has been limited. A number of factors contribute to this, including epidemiological differences in GIT neoplasia between Western and Eastern populations and limitations in training opportunities. In this review, we discuss the role of ESD, its current status and the future in Western endoscopic practice.     

Training in endoscopic submucosal dissection from a Western perspective

Endoscopic submucosal dissection (ESD) is a mature endoscopic procedure that was developed in Japan to enable the en bloc, curative resection of superficial dysplastic lesions in the luminal gastrointestinal tract that have a low risk of lymph node metastasis. ESD requires a cognitive understanding of endosurgical principles, the ability to apply advanced optical imaging techniques to diagnose and stage lesions, and a high degree of endoscopic skill. Training in ESD should ideally begin with small lesions in the distal stomach, but such an approach is not applicable to endoscopists who are trying to learn and perform ESD in Western countries; as such, a “prevalence-based approach” is required that might vary from country to country. Proposed thresholds for attaining and maintaining competence in ESD, particularly for Western endoscopists, include rates of en bloc resection ≥80% and adverse events ≤10%. Endoscopists skilled in ESD should achieve rates of en bloc resection ≥90% and adverse events ≤5%. In order to offer ESD on a national level, a critical mass of endoscopists proficient in ESD is required who can then establish regional or national training centers and teach others with the requisite endoscopic skill and experience how to perform this elegant procedure. In the United States, ESD-specific billing codes are required to defray the procedural cost for endoscopy centers and health systems and to adequately compensate those endoscopists who offer this procedure as a life-saving alternative to more invasive surgical resection.     

Endoscopic submucosal dissection of early gastric cancer

The purpose of this review was to examine a remarkable technical advance regarding the indications for and the technique of endoscopic resection of early gastric cancer. Endoscopic mucosal resection (EMR) of early gastric cancer with no risk of lymph node metastasis has been a standard technique in Japan, probably owing to the high incidence of gastric cancer in Japan and the fact that more than half of Japanese gastric cancer cases are diagnosed at an early stage. Very recently, several EMR techniques have become increasingly accepted and regularly used in Western countries. Although these minimally invasive techniques are safe, convenient, and efficacious, they are unsuitable for large lesions in particular. Difficulty in correctly assessing the depth of tumor invasion and an increase in local recurrence when standard EMR procedures are used have been reported in cases of large lesions, because such lesions are often resected piecemeal owing to the technical limitations of standard EMR. A new development in therapeutic endoscopy, called endoscopic submucosal dissection (ESD), allows the direct dissection of the submucosa, and large lesions can be resected en bloc. ESD is not limited by resection size and is expected to replace surgical resection. However, it is still associated with a higher incidence of complications than standard EMR procedures and requires a high level of endoscopic skill. The endoscopic indications, techniques, and management of complications of ESD for early gastric cancer for properly carrying out established therapeutic endoscopy are described.     

Endoscopic submucosal dissection of early gastric cancer

Endoscopic mucosal resection (EMR) of early gastric cancer (EGC) without any risk of lymph node metastasis was developed in Japan in the 1980s, and it has been one of the standard treatments of EGC for nearly 20 years. Recently, several EMR techniques developed in Japan have been accepted and done in Western countries. These EMR techniques are safe and efficacious but unsuitable for large lesions. Because we could not remove a large lesion in 1 fragment, which was very important for the precise diagnosis of tumor depth, local recurrence increased in large-lesion cases. An innovative procedure using newly developed endoscopic knives, called endoscopic submucosal dissection (ESD), was developed in the late 1990s, which made it possible to remove a large lesion en bloc. Theoretically, ESD has no limitation with respect to tumor size; therefore, it is expected to replace the surgical treatment in some situations. Although ESD has spread throughout Japan within a short period, there remain several disadvantages, such as a higher incidence of complications and a requirement of higher endoscopic skills compared to those of conventional EMR methods. The endoscopic indications, procedures, complications and treatment outcomes of the ESD of EGC are described in this review.     

CURRENT TECHNIQUES AND DEVICES FOR SAFE AND CONVENIENT ENDOSCOPIC SUBMUCOSAL DISSECTION (ESD) AND KOREAN EXPERIENCE OF ESD

Conventional endoscopic mucosal resection (EMR) technique has limitations in its capacity of achieving en bloc resection and, for lesions greater than 20 mm, removal in a piecemeal resection is often required. This leads to uncertainty as to whether or not the lesion has been completely removed and to an increase in local recurrence. To overcome this limitation, a new technique using specifically designed cutting devices, termed endoscopic submucosal dissection (ESD) has been developed. The present article discuss the current indication, new diagnostic, cutting and hemostatic devices and long‐term outcomes of EMR and ESD in early gastric cancer in Korea.     

重视并开展内镜黏膜下剥离术的规范化操作

内镜切除术治疗胃肠道早期肿瘤正日益被接受并开展应用,包括传统的内镜黏膜切除术（EMR）和近年开展的内镜黏膜下剥离术（ESD）。EMR对于15mm以上的病灶较难做到一次切除,而整块切除标本对病理学评估至关重要,ESD正是应这一要求开展起来的新技术。对局限于黏膜层的病变,ESD并不受其大小的限制,对部分早期胃肠道肿瘤,其可取代传统的手术治疗,但ESD需要相当高的内镜操作技术,术前需要多种方法对病灶进行谨慎、全面的评估,包括范围、浸润深度等,术中、术后还可能出现出血、穿孔等严重的并发症,其发生率远高于EMR。ESD的指征、操作技巧、病理评估等方面还需要不断完善。由于ESD在早期胃肠道肿瘤的治疗上具有很多优点,值得有条件医院的内镜医师予以重视并开展这一技术。     

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.     

Advantage of endoscopic submucosal dissection compared with EMR for early gastric cancer

BACKGROUND: In EMR of early gastric cancer (EGC), en bloc resection reduces the risk of residual cancer. Endoscopic submucosal dissection (ESD) now allows en bloc resection of large EGCs. OBJECTIVE: To retrospectively determine whether ESD is more advantageous than EMR for EGCs. DESIGN: EMR (825 lesions, 711 patients) or ESD (195 lesions, 185 patients) was performed. The en bloc resection rate, histologically complete resection rate, operation time, complications, and local recurrence rate were studied in relation to ulceration. SETTING: Hiroshima University Hospital. PATIENTS: Subjects comprised 896 patients in whom 1020 EGCs were resected endoscopically from 1990 to 2004. RESULTS: In cases without ulceration, en bloc and histologically complete resection rates were significantly higher with ESD than with EMR, regardless of tumor size. The frequency of ulceration did not differ significantly between groups. Average operation time was significantly longer for ESD than for EMR, regardless of tumor size. Also, regardless of ulceration, the incidence of intraoperative bleeding was significantly higher with ESD (22.6%) than with EMR (7.6%). Delayed bleeding did not differ. In cases with ulceration, the incidence of perforation was significantly higher with ESD (53.8%) than with EMR (2.9%). Local recurrences were treated by incomplete EMR (en bloc, 2.9%; piecemeal, 4.4%). No patient experienced recurrence after ESD. CONCLUSIONS: ESD increased en bloc and histologically complete resection rates and may reduce the local recurrence rate. Increased operation time and complication risks with ESD in comparison with EMR remain problematic. Special measures are necessary for ESD of ulcerated lesions to reduce the rates of perforation and incomplete resection.     

Endoscopic submucosal dissection-current success and future directions

More than 10 years have passed since endoscopic submucosal dissection (ESD) was first developed in Japan. ESD enables en bloc complete resection of superficial gastrointestinal neoplasms regardless of the size and location of the lesions. With improvements in techniques and devices, excellent therapeutic results have been achieved despite the inherent technical difficulties of this procedure. ESD aiming for curative treatment can be performed for gastrointestinal neoplasms without risk of lymph node metastasis. Accurate histopathologic examination of the resected specimen is required to determine the risk of lymph node metastasis, for which en bloc resection is beneficial. Owing to the high success rate of en bloc complete resection and accurate histopathologic examination, tumour recurrence rates after ESD are reported to be very low in Japan. Excellent results of ESD in a large number of cases have also been reported from other Asian countries such as South Korea, Taiwan and China. Although scepticism exists among Western clinicians regarding the application of ESD, it is developing slowly and reports indicate promising results in some European countries. With further development of technologies, such as endoscopic robotics, ESD could become the worldwide treatment of choice for early gastrointestinal neoplasms.     

Endoscopic mucosal resection and endoscopic submucosal dissection of epithelial neoplasia of the colon

Endoscopic mucosal resection (EMR) with curative intent has evolved into a safe and effective technique and is currently the gold standard for management of large colonic epithelial neoplasms. Piecemeal EMR is associated with a high risk of local recurrence requiring vigilant surveillance and repeat interventions. Endoscopic submucosal dissection (ESD) was introduced in Japan for the management of early gastric cancer, and has recently been described for en bloc resection of colonic lesions greater than 20 mm. En bloc resection allows accurate histological assessment of the depth of invasion, minimizes the risk of local recurrence and helps determine additional therapy. Morphologic classification of lesions prior to resection allows prediction of depth of invasion and risk of nodal metastasis, allowing selection of the appropriate intervention. This review provides an overview of the assessment of epithelial neoplasms of the colon and the application of EMR and ESD techniques in their management.     

RISK MANAGEMENT OF THERAPEUTIC COLONOSCOPY (HOT BIOPSY,POLYPECTOMY, ENDOSCOPIC MUCOSAL RESECTION AND ENDOSCOPIC SUBMUCOSAL DISSECTION)

The concept of an adenoma–carcinoma sequence has been widely accepted in the colon and rectum, contrary to that in gastric cancer. Consequently, most target lesions for endoscopic resection using these newly developed techniques are histologically assessed as adenoma or intramucosal carcinoma in adenoma. Based on results in conventional endoscopic mucosal resection (EMR), almost all remnant or recurrent tumors can be successfully managed by salvage EMR, and all materials resected by salvage EMR also showed adenoma or intramucosal cancer. These results suggest that en bloc resection is not always clinically necessary to obtain complete cure for all colorectal neoplasia. However, larger lesions tend to be resected in a piecemeal fashion; it is difficult to confirm whether EMR has been completed or not. For precise histopathological assessment of the resected specimen, endoscopic submucosal dissection (ESD) for en bloc resection is desirable, although further experience is needed to establish its safety and efficacy. The present review contains a summary of the risk management of therapeutic colonoscopy including ESD for large colorectal mucosal neoplasia, debated at the Endoscopic Forum Japan 2006, Hakone, and discussion of the problems and future prospects of these procedures.     

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.     

Investigation of ulcer healing after esophageal EMR/ESD

Background  

Endoscopic mucosal resection (EMR) for early esophageal cancer has become popular. Recently, endoscopic submucosal dissection (ESD) has been used to excise widespread lesions en bloc. However, the time required for the ulcer to heal has not been clarified. Therefore, we investigated the healing time of ulcers that were formed after EMR/ESD.     

Endoscopic submucosal dissection with internal traction for early gastric cancer (with video)

BACKGROUND: EMR techniques have high success rates for treating small lesions of the upper-GI tract; however, tumors larger than 15 mm are frequently removed by piecemeal resection, which is associated with an increased rate of disease recurrence and difficulty in histologically evaluating the specimen. OBJECTIVE: To describe a simple technique of using internal traction to facilitate endoscopic submucosal dissection (ESD) procedures in the excision of large, early gastric cancers. DESIGN: Case series. SETTING: A tertiary medical center in Taiwan. PATIENTS AND METHODS: Eight patients with early gastric cancers larger than 20 mm underwent ESD. INTERVENTIONS: A standard hemoclip modified with surgical suture was used to provide traction to improve visualization of the dissection plane during ESD. MAIN OUTCOME MEASUREMENTS: Proportion with complete en bloc resection. RESULTS: En bloc resection of the lesion was achieved in 8 patients. One patient underwent additional surgery because an adequate safe margin was not obtained by ESD. LIMITATIONS: One endoscopist performed all procedures, and only 8 patients were studied in an uncontrolled manner. CONCLUSIONS: The internal traction method appears to facilitate en bloc ESD of early gastric cancers larger than 20 mm.     

内镜下黏膜剥离术在高风险/高难度病例治疗中的应用

内镜下黏膜剥离术(ESD)已越来越多地应用于消化道早期肿瘤及癌前病变的微创治疗。与内镜下黏膜切除术(EMR)相比,ESD可完整切除病灶,切除较大病灶、平坦型病灶以及溃疡型病灶,从而利于完整的病理学诊断及减少复发,且相对外科手术来说,其安全性高、死亡率低、损伤小、恢复快,具有与外科手术类似的治疗效果,为消化道早期肿瘤的治疗开辟了新的途径。本文就ESD在切除特殊病灶(巨大肿瘤、十二指肠肿瘤、胃黏膜下肿瘤和咽喉癌)及在特殊患者(早期残胃癌、高龄、肝硬化和慢性肾功能衰竭血透患者)中的应用作一概述。     

Matched case-control study comparing endoscopic submucosal dissection and endoscopic mucosal resection for colorectal tumors

Background and Aim: For large colorectal tumors, the en bloc resection rate achieved by endoscopic mucosal resection (EMR) is insufficient, and this leads to a high rate of local recurrence. As endoscopic submucosal dissection (ESD) has been reported to achieve a higher rate of en bloc resection and a lower rate of local recurrence in the short‐term, it is expected to overcome the limitations of EMR. We conducted a matched case‐control study between ESD and EMR to clarify the effectiveness of ESD for colorectal tumors. Methods: Between April 2005 and February 2009, a total of 28 colorectal tumors in 28 patients were resected by ESD and were followed up by colonoscopy at least once. As a control group, 56 EMR cases from our prospectively completed database were matched. En bloc resection, complication and recurrence rates were compared between the two groups. Results: The mean sizes of the lesions were 27.1 mm in the ESD group and 25.0 mm in the EMR group. The en bloc resection rate was significantly higher in the ESD group (92.9% vs 37.5% with ESD vs EMR), and the rate of perforation was also significantly higher (10.7% vs 0%). All cases of perforation were managed conservatively. No recurrence was observed in the ESD group, whereas local recurrences were detected in 12 EMR cases (21.4%). Eleven of the 12 recurrences (91.7%) were managed endoscopically, and one required surgical resection. Conclusions: Endoscopic submucosal dissection is a promising technique for the treatment of colorectal tumors, giving an excellent outcome in comparison with EMR.     

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

OBJECTIVES: Endoscopic mucosal resection (EMR) has been shown to be safe and effective. En bloc resection is often not achieved using conventional EMR. Insulated-tip knife (It-knife) EMR has been recently proposed for early gastric cancer dissection and removal. This study was conducted to evaluate the safety and efficacy in obtaining en bloc resection with It-knife EMR of large colonic lesions not resectable with standard endoscopic techniques. METHODS: A total of 29 patients (19 men, 10 women, mean age 67.5 yr, range 44-88) were included in the study. Lesions were considered not suitable for standard polypectomy because of large diameter (>3 cm), morphology, and/or position. Lesions were located in the rectum (N = 11), sigmoid: (N = 10), descending: (N = 4), transverse: (N = 2), and hepatic flexure (N = 2). After saline injection, circumferential incision and dissection of the lesions were attempted with the aim of achieving en bloc resection. RESULTS: En bloc resection was achieved in only 55.1% of the lesions (16 out of 29 patients). In the remaining cases, resection was completed with a piecemeal technique. The median size of the en bloc resected specimen was 3 x 3.4 cm. Complications occurred in four patients (13.7%). At histopathology, 13 patients had low-grade dysplasia, 15 high-grade dysplasia. One patient had a tumor invading the submucosa and was submitted to surgery. CONCLUSIONS: It-knife EMR is a promising technique for attempting en bloc resection of large colonic polyps. Adequate training and caution are required because it can be associated with a higher complication rate than with other EMR modalities.     

Importance of histological evaluation in endoscopic resection of early colorectal cancer

The diagnostic criteria for colonic intraepithelial tumors vary from country to country.While intramucosal adenocarcinoma is recognized in Japan,in Western countries adenocarcinoma is diagnosed only if the tumor invades to the submucosa and accesses the muscularis mucosae.However,endoscopic therapy,including endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD),is used worldwide to treat adenoma and early colorectal cancer.Precise histopathological evaluation is important for the curativeness of these therapies as inappropriate endoscopic therapy causes local recurrence of the tumor that may develop into fatal metastasis.Therefore,colorectal ESD and EMR are not indicated for cancers with massive submucosal invasion.However,diagnosis of cancer with massive submucosal invasion by endoscopy is limited,even when magnifying endoscopy for pit pattern and narrow band imaging and flexible spectral imaging color of enhancement are performed.Therefore,occasional cancers with massive submucosal invasion will be treated by ESD and EMR.Precise histopathological evaluation of these lesions should be performed in order to determine the necessity of additional therapy,including surgical resection.