Warning for unprincipled colorectal endoscopic submucosal dissection: Accurate diagnosis and reasonable treatment strategy

Piecemeal endoscopic mucosal resection (EMR) is generally indicated for laterally spreading tumors (LST) >2 cm in diameter. However, the segmentation of adenomatous parts does not affect the histopathological diagnosis and completeness of cure. Thus, possible indications for piecemeal EMR are both adenomatous homogenous‐type granular‐type LST (LST‐G) and LST‐G as carcinoma in adenoma without segmentalizing the carcinomatous part. Diagnosis of the pit pattern using magnifying endoscopy is essential for determining the correct treatment and setting segmentation borders. In contrast, endoscopic submucosal dissection (ESD) is indicated for lesions requiring endoscopic en bloc excision, as it is difficult to use the snare technique for en bloc excisions such as in non‐granular‐type LST (LST‐NG), especially for the pseudodepressed type, tumors with a type V_I pit pattern, shallow invasive submucosal carcinoma, largedepressed tumors and large elevated lesions, which are often malignant (e.g. nodular mixed‐type LST‐G). Other lesions, such as intramucosal tumor accompanied by submucosal fibrosis, induced by biopsy or peristalsis of the lesion; sporadic localized tumors that occur due to chronic inflammation, including ulcerative colitis; and local residual early carcinoma after endoscopic treatment, are also indications for ESD. In clinical practice, an efficient endoscopic treatment with segregation of ESD from piecemeal EMR should be carried out after a comprehensive evaluation of the completeness of cure, safety, clinical simplicity, and cost–benefit, based on an accurate preoperative diagnosis.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR RECURRENT GASTRIC TUMORS

Endoscopic resection has been accepted as the standard treatment for intramucosal gastric tumors of differentiated type. However, the indication was limited to small tumors to achieve en bloc resection and prevent local recurrence in cases of conventional endoscopic mucosal resection (EMR) such as the strip biopsy and the cap technique. To avoid multi‐fragmental resection, we have developed endoscopic submucosal dissection (ESD) as a new endoscopic resection technique. ESD is a remarkable technique, because we make it possible to remove the lesions en bloc regardless of size, shape, coexisting ulcer, and location. However, it is difficult or impossible to resect recurrent tumors en bloc in conventional EMR owing to hard fibrosis, and some patients need laparotomy. Using ESD, we can dissect the submucosal layer as we directly look at the submucosa, and remove the lesion safely and reliably even in cases of hard fibrosis. The key to treatment of recurrent tumors in ESD are as follows: (i) using enough submucosal injection solution (we use a mixture of Glyceol and 1% 1900 kDa hyaluronic acid preparation); (ii) incising the mucosa without fibrosis; (iii) understanding characteristics of various cutting devices, and changing other devices in difficult situations. In these ways we can remove the majority of the recurrent tumors en bloc. Hence, we consider that ESD is a very effective treatment which achieves excellent en bloc and complete resection rates and enables patients with intramucosal gastric tumors to a recurrent‐free survival even in recurrent tumors.     

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.     

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.     

Magnifying endoscopy in upper gastroenterology for assessing lesions before completing endoscopic removal

Any prognosis of gastrointestinal (GI) cancer is closely related to the stage of the disease at diagnosis. Endoscopic submucosal dissection (ESD) and en bloc endoscopic mucosal resection (EMR) have been performed as curative treatments for many early-stage GI lesions in recent years. The technologies have been widely accepted in many Asian countries because they are minimally invasive and supply thorough histopathologic evaluation of the specimens. However, before engaging in endoscopic therapy, an accurate diagnosis is a precondition to effecting the complete cure of the underlying malignancy or carcinoma in situ. For the past few years, many new types of endoscopic techniques, including magnifying endoscopy with narrow-band imaging (ME-NBI), have emerged in many countries because these methods provide a strong indication of early lesions and are very useful in determining treatment options before ESD or EMR. However, to date, there is no comparable classification equivalent to "Kudo's Pit Pattern Classification in the colon", for the upper GI, there is still no clear internationally accepted classification system of magnifying endoscopy. Therefore, in order to help unify some viewpoints, here we will review the defining optical imaging characteristics and the current representative classifications of microvascular and microsurface patterns in the upper GI tract under ME-NBI, describe the accurate relationship between them and the pathological diagnosis, and their clinical applications prior to ESD or en bloc EMR. We will also discuss assessing the differentiation and depth of invasion, defying the lateral spread of involvement and targeting biopsy in real time.     

Current status and future perspectives of endoscopic submucosal dissection for colorectal tumors

Endoscopic submucosal dissection (ESD) allows for en bloc tumor resection irrespective of the size of the lesion. In Japan, ESD has been established as a standard method for endoscopic ablation of malignant tumors in the upper gastrointestinal tract. Although the use of colorectal ESD has been gradually spreading with the development of numerous devices, ESD has not yet been fully established as a standard therapeutic method for colorectal lesions. Currently, colorectal ESD is performed as an 'advanced medical treatment' without national health insurance coverage. With the recent accumulation of numerous cases, the safety and simplicity of colorectal ESD have improved remarkably. Currently in Japan, a prospective multicenter cohort study organized by the Japan Gastroenterological Endoscopy Society is ongoing to clarify the safety and efficacy of colorectal ESD to obtain remuneration from national health insurance. In this report, we showed the outcome regarding safety and efficacy of colorectal ESD through a review of the published work. Of 2719 cases with colorectal ESD at 13 institutions, the complete en bloc resection and perforation rates were 82.8% (61-98.2%, 2082/2516) and 4.7% (1.4-8.2%, 127/2719), respectively. Additional surgery for perforation was very rare because perforations were tiny enough to be closed endoscopically by clips in most of the cases and treated conservatively. In the near future, colorectal ESD will be a common therapeutic method for early colorectal carcinoma.     

Clinical impact of endoscopic submucosal dissection for superficial adenocarcinoma located at the esophagogastric junction

BACKGROUND: Surgery is the standard treatment for neoplasms located at the esophagogastric junction (EGJ), and, recently, EMR, photodynamic therapy (PDT), or both have also been used for early stage neoplasms located at the EGJ. Endoscopic submucosal dissection (ESD) is a newly developed technique in the field of endoscopic treatments for GI neoplasms because of its high rate of en bloc resection. OBJECTIVE: We used ESD for superficial adenocarcinoma located at the EGJ and evaluated its clinical impact. PATIENTS: Twenty-five lesions of superficial adenocarcinomas located at the EGJ from 24 patients were treated with ESD between June 2001 and January 2006. An adenocarcinoma located at the EGJ was defined as a "junctional carcinoma (type II)" according to Siewert's classification. MAIN OUTCOME MEASUREMENT: Complications, en bloc resection rate, curative resection rate, local recurrence, and distant metastasis were evaluated. RESULTS: No complications except stenosis occurred. The en bloc resection rate was 100%. Seventeen lesions (72.0%) were judged as "curative resection" and showed no local or distant recurrence during a median follow-up period of 30.1 months. Seven lesions were diagnosed as "noncurative resection." Two patients underwent additional surgical resections. In 1 of 2 of the surgical resections, however, we could not identify a residual cancer. In 1 patient, who refused additional surgical resection, lung metastases were found after 3 years. LIMITATIONS: The limitation of the study was its retrospective design. CONCLUSIONS: After long-term follow-up, although surgery for a noncurative resection remains a standard treatment, ESD can be adequately adopted as an effective treatment for superficial adenocarcinomas at the EGJ.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR THE RELIABLE EN BLOC RESECTION OF COLORECTAL MUCOSAL TUMORS

Scheduled piecemeal resection has been actively conducted for granular type laterally spreading tumor (LST‐G) in Japan, as long as a definite preoperative diagnosis is made. However, en bloc resection is desirable for depressed lesions (e.g. IIc lesion) as well as non‐granular type laterally spreading tumor (LST‐NG) since they have considerable high risk for submucoasl invasion and require precise histopathological evaluation. Endoscopic submucosal dissection (ESD) has been developed for the en bloc resection of mucosal tumors of gastrointestinal tract and widely applied especially in gastric lesions. Although the large intestine involves structural and technical difficulties, we conducted en bloc resection by ESD while exercising sorts of ingenuity for preparation; endoscopes, instruments, local injections, and others. ESD is a reliable technique that allows en bloc resection of gastrointestinal mucosal lesions, and even has a splendid possibility for the treatment of early stage colorectal cancer.     

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.     

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) in 2011, a Western perspective

Endoscopic mucosal resection (EMR) has become the standard of care for removal of large flat and sessile neoplastic lesions of the GI tract. Recently, endoscopic submucosal dissection (ESD) was introduced in Japan as an alternative technique, which allows en bloc resection of large lesions. The applications of EMR and ESD are expanding and many Western endoscopists are adopting these techniques. Paris classification and Kudo pit pattern classification allows prediction of the depth of invasion of early neoplastic lesions and thus, avoids resection of lesions invading the deep submucosa which have higher rates of lymphatic spread. ESD of early stomach cancer is the standard of care in Japan. Recent published reports from Western countries showed comparable results for ESD of early gastric cancers to those done in Japan. Recently, EMR combined with ablation has been used frequently in Western countries for treatment of high-grade dysplasia in early adenocarcinoma of the esophagus. Although ESD of early neoplastic lesions of the esophagus is technically difficult, few promising reports were published proving the feasibility of this technique in the West. ESD has been shown to achieve higher en bloc resection and lower rates of tumour recurrence in removal of lateral spreading colonic polyps. A hybrid technique of circumferential submucosal incision followed by en bloc EMR has been used for removal of large colonic lesions in some Western endoscopy centres. In Western countries, training for ESD is challenging given the lack of training in the relatively easier early gastric cancer lesions. Animal model training combined with observing experts in ESD could be an alternative for Western endoscopists. Inspite of obstacles, ESD applications are continuing to grow in Western countries.     

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.     

Treatment strategy for laterally spreading tumors in Japan: Before and after the introduction of endoscopic submucosal dissection

Background and Aims:  Laterally spreading tumors (LST) in the colorectum are considered good candidates for endoscopic resection (ER). Because LST-non-granular (NG) tumors show multifocal invasion into the submucosal layer, en bloc resection is necessary for adequate histopathological evaluation. Therefore, surgical resection has been recommended when a lesion is suspected to be an invasive cancer and too large to resect en bloc. The aim of the present study was to evaluate whether the introduction of colorectal ESD, which was developed for en bloc resection of early gastric cancers, could improve the en bloc resection rate of large LST-NG-type tumors and reduce the surgical resection rate.
Methods:  Between January 1999 and December 2005, a total of 166 LST-NG-type tumors measuring ≥ 20 mm in 161 patients were included in this study. The en bloc resection rate and the surgical resection rate were historically compared between two periods, before and after the introduction of ESD.
Results:  The en bloc resection rate for ER lesions was significantly higher in the latter period (35.0% [14/40] vs 76.5% [75/98]; P  < 0.001), and the rate of surgery for adenomas and intramucosal or sm minute cancers was significantly lower in the latter period (20.0% [10/50] vs 1.1% [1/89]; P  < 0.001).
Conclusions:  The introduction of colonic ESD was able to change our treatment strategy for LST, improving the en bloc resection rate and reducing the surgical resection rate.     

Endoscopic mucosal resection with a ligation device or endoscopic submucosal dissection for rectal carcinoid tumors: An analysis of 24 consecutive cases

Aims: Endoscopic submucosal dissection (ESD) has several advantages over conventional endoscopic mucosal resection, including a higher en bloc resection rate and more accurate pathological estimation. However, ESD is a complex procedure that requires advanced endoscopic skills. The aim of our study is to evaluate the efficacy of endoscopic mucosal resection with a ligation device (EMR‐L) compared to ESD for rectal carcinoid tumors. Methods: Between September 2003 and April 2011, 24 rectal carcinoid tumors in 24 patients treated by ESD or EMR‐L were retrospectively analyzed. The indications for endoscopic treatment were node‐negative rectal carcinoid tumors. We compared the therapeutic outcomes of the ESD group (n = 13) and the EMR‐L group (n = 11). Results: Both groups had similar mean tumor sizes (ESD: 5.5 ± 2.1 mm; EMR‐L: 4.4 ± 2.2 mm). The rates of en bloc and complete resection were, respectively, 100% and 92.3% for ESD, and 100% and 100% for EMR‐L. Perforations did not occur in either group. Postoperative bleeding occurred in one EMR‐L case, and it was endoscopically managed. However, there were no differences in therapeutic outcomes between the two groups. The mean procedure time was longer in the ESD group (28.8 ± 16.2 min) than in the EMR‐L group (17.4 ± 4.4 min), without a significant difference. The mean hospitalization period was significantly shorter in the EMR‐L group (1.8 ± 3.1 day) than in the ESD group (6.2 ± 2.1 day), and eight EMR‐L cases were treated in an outpatient setting. Conclusions: EMR‐L is a simple and effective procedure that compares favorably to ESD for small rectal carcinoid tumors.     

Risk factors for incomplete resection and complications in endoscopic mucosal resection for lateral spreading tumors

Aim: Lateral spreading tumors (LST) are relatively large flat lesions with diameters exceeding 10 mm in length. Endoscopic mucosal resection (EMR) is a commonly used technique for removing LST. We aimed to evaluate the risk factors for incomplete resection and complications of EMR for LST. Method: Between January 2004 and December 2010, 497 patients who underwent EMR for LST were retrospectively reviewed. Risk factors for endoscopic and histopathological complete resection, complications, and clinical outcomes were investigated. Results: Risks for incomplete resection by piecemeal resection and en bloc resection of a lesion ≥30 mm were higher than for en bloc resection of a lesion <30 mm (OR = 2.688, CI 1.036–6.993; OR = 4.982, CI 1.894–13.101). Risks of post‐EMR bleeding for piecemeal resection and en bloc resection for a lesion ≥40 mm were higher than for en bloc resection of a lesion < 40 mm (OR = 15.231, CI 1.816–127.744; OR = 43.043, CI 4.306–430.314). Conclusion: We found risk factors of EMR for LST and tentatively suggest a protocol for EMR adapted to the size of LST and resection methods. (i) Following piecemeal resection and en bloc resection for LST ≥ 40 mm, hospitalize patients for 36 h and note risk for incomplete resection and delayed bleeding. (ii) After en bloc resection for 40 mm > LST ≥ 30 mm, hospitalize patients for 12 h and note risk for incomplete resection. (iii) Following en bloc resection for LST < 30 mm, hospitalize the patient for 12 h and expect complete resection.     

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.     

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 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.     

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 r...     

Local recurrence of large squamous-cell carcinoma of the esophagus after endoscopic resection

BACKGROUND: A new technique, endoscopic submucosal dissection (ESD), which uses specially developed endoscopic knives, was recently developed for en bloc resection of large lesions. Despite increasing indications for endoscopic resection (ER), there are limited data available regarding the outcome of ER for lesions 20 mm or more in diameter. OBJECTIVE: To investigate the risk factors for local recurrence. DESIGN: Retrospective cohort study. SETTING: A cancer-referral center. PATIENTS: Seventy patients, who presented between September 1994 and April 2006, with a total of 78 lesions that measured 20 mm or more in diameter. MAIN OUTCOME MEASUREMENT: Local recurrence rate after ER was assessed. RESULTS: At a median follow-up of 32 months (range 12-121 months), there were 12 local recurrences (15.4%). There was no significant association between local recurrence and multiple iodine-voiding lesions, tumor size, or tumor location. The number of resections and the resection method, however, were significantly associated with local recurrence. There was no recurrence of lesions treated by en bloc resection. Lesions resected in 5 or more pieces had a significantly higher recurrence rate than lesions resected in 2 to 4 pieces. Lesions treated by EMR had a significantly higher recurrence rate than lesions treated by ESD. LIMITATIONS: Single-center retrospective analysis. CONCLUSIONS: Esophageal squamous-cell carcinoma that measured 20 mm or more in diameter should be resected en bloc by ESD. Lesions treated by resection in 5 or more pieces have a higher risk for local recurrence.     

Benefits of endoscopic submucosal dissection according to size and location of gastric neoplasm, compared with conventional mucosal resection

Background and Aims:  To clarify optimal therapeutic strategies for early gastric cancers without vestigial remnant or recurrence, we evaluated the benefits of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) according to tumor size and location.
Methods:  From January 2000 to December 2007, a total of 328 gastric lesions were treated using conventional EMR, while 572 lesions were treated by ESD. Patients who underwent surgery on the upper gastrointestinal tract before EMR or ESD were excluded from the study. We compared tumor size, location and rates of complete resection, curative resection, postoperative bleeding, perforation and local recurrence between EMR and ESD according to tumor situation.
Results:  Overall local complete resection rate (EMR, 64.2%; ESD, 95.1%) and overall curative resection rate (EMR, 59.5%; ESD, 82.7%) were significantly higher in ESD than in EMR. No significant differences were seen in complication rates between EMR and ESD. Local recurrence was detected in 13 lesions (4.0%) of the EMR group during follow up. In contrast, no local recurrence was detected in the ESD group. For lesions 5 mm or less in diameter, complete resection rate in the EMR group was not significantly inferior to that in the ESD group at any location. However, rates were overwhelmingly better in the ESD group than in the EMR group for lesions more than 5 mm in diameter, regardless of location.
Conclusion:  We concluded that lesions exceeding 5 mm in diameter should be treated by ESD, although a high resection rate is obtained also with EMR for lesions of 5 mm or less in diameter.