ENDOSCOPIC SUBMUCOSAL DISSECTION FOR EARLY GASTRIC CANCER: TECHNICAL FEASIBILITY,OPERATION TIME AND COMPLICATIONS FROM A LARGE CONSECUTIVE SERIES

Background: Endoscopic mucosal resection (EMR) is a recognized treatment for early gastric cancer (EGC). One‐piece resection is considered to be a gold standard of EMR, as it provides accurate histological assessment and reduces the risk of local recurrence. Endoscopic submucosal dissection (ESD) is a new technique developed to obtain one‐piece resection even for large and ulcerative lesions. The present study aims to identify the technical feasibility, operation time and complications from a large consecutive series. Methods: We reviewed all patients with EGC who underwent ESD using the IT knife at National Cancer Center Hospital in the period between January 2000 and December 2003. Results: During the study period of 4 years we identified a total of 1033 EGC lesions in 945 consecutive patients who underwent ESD using the IT knife. We found a one‐piece resection rate (OPRR) of 98% (1008/1033). Our OPRR with tumor‐free margins was 93% (957/1033). On subgroup analysis it was found to be 86% (271/314) among large lesions (≥ 21 mm) and 89% (216/243) among ulcerative lesions. The overall non‐evaluable resection rate was 1.8% (19/1033). The median operation time was 60 min (range; 10–540 min). Evidence of immediate bleeding was found in 7%. Delayed bleeding after ESD was seen in 6% and perforation in 4% of the cases. All cases with complications except one were successfully treated by endoscopic treatment. Conclusion: The present study shows the technical feasibility of ESD, which provides one‐piece resections even in large and ulcerative EGC.     

Endoscopic submucosal dissection for early gastric cancer

Endoscopic mucosal resection (EMR) has been accepted as a treatment of early gastric cancer (EGC). The number of EMR procedures for EGC has been increasing because a patient's quality of life after EMR is superior to that after surgical gastrectomy. In Japan, most EMR have been performed using the strip biopsy method; however, in some cases we experienced local recurrences when multiple fragments had been resected by this method. Single-fragment resection is preferable for correct histological diagnosis and a patient's prognosis. Recently, dramatic changes have occurred in the operational technique and design of the accessory apparatus. In 1996, we developed a special endoscopic knife, called the insulation-tipped electrosurgical knife (IT knife), which consists of a conventional diathermic needle knife with a ceramic ball at the top to minimize the risk of perforation. This knife can cut submucosa safely and remove a lesion completely. We named this method endoscopic submucosal dissection (ESD). Using this procedure, 96% of the tumors (471/488) were completely resected in one piece. During the follow-up period, there were no recurrent cases. One-piece resection by ESD using the IT knife improves the quality of life and prognosis for patients with early gastric cancer.     

Early gastric cancer: diagnosis, pathology, treatment techniques and treatment outcomes

Recent improvements in endoscopic techniques and technologies and an increased understanding and recognition of the importance of early gastric cancer (EGC) will result in increases in the detection and diagnosis of precancerous or early cancerous lesions. The incidences of nodal metastasis of intramucosal and submucosal EGC are 3 and 20%, respectively. Therefore, major surgery may be inappropriate in many of these patients, and many cases of EGC may be treated by endoscopic mucosal resection (EMR). EMR was first introduced in Japan 20 years ago. Most EMR have been performed by the so-called 'strip biopsy' or EMR-C methods. However, we have sometimes experienced local recurrence in cases that had been resected in multiple fragments by these methods. To obtain 'complete resection', we developed the endoscopic submucosal dissection (ESD) technique using a special endoscopic knife, the insulation-tipped diathermic knife (IT knife). The rate of complete resection, i.e. cut margin free from cancer and one-piece resection, was remarkably higher for the IT knife technique than conventional EMR. ESD cases are increasing rapidly in Japan. EMR including ESD is a good method for patients with gastric cancer to preserve the stomach. For EMR, it is necessary to find EGC. Both diagnosis and treatment are important, and scientific data regarding lymph node metastasis and clinicopathological features are required.     

ENDOSCOPIC MUCOSAL RESECTION AND SUBMUCOSAL DISSECTION METHOD FOR LARGE COLORECTAL TUMORS

The goal of endoscopic mucosal resection (EMR) is to allow the endoscopist to obtain tissue or resect lesions not previously amenable to standard biopsy or excisional techniques and to remove malignant lesions without open surgery. In this article, we describe the results of conventional EMR and EMR using an insulation‐tipped (IT) electrosurgical knife (submucosal dissection method) for large colorectal mucosal neoplasms and discuss the problems and future prospects of these procedures. At present, conventional EMR is much more feasible than EMR using IT‐knife from the perspectives of time, money, complication, and organ preservation. However, larger lesions tend to be resected in a piecemeal fashion; and it is difficult to confirm whether EMR has been complete. For accurate histopathological assessment of the resected specimen en bloc EMR is desirable although further experience is needed to establish its safety and efficacy. Further improvements of in EMR with special knife techniques are required to simply and safely remove large colorectal neoplasms.     

Endoscopic Mucosal Resection for Early Gastric Cancer: Aiming at Safety,Speed, and Reliability

We assessed the non‐marginating surgical techniques of endoscopic mucosal resection (EMR) for early gastric cancer, represented by the ‘double‐channel’ method and the suction method, and the marginating surgical techniques, represented by the ‘insulation tip’ (IT) and the ‘endoscopic resection with high saline epinephrine’ (ERHSE) methods, and reviewed cases in the literature and our own cases from the standpoint of complications and duration of therapy with each method. Bleeding occurred in 3.6–4.5% of the cases treated by the non‐marginating surgical techniques and 17% of the cases treated by the marginating surgical techniques. Perforation occurred in only 0.3% of the cases treated by the non‐marginating surgical techniques, as opposed to 6.7% of the cases treated by the marginating surgical techniques. The results of EMR with a new type of therapeutic scope, the multi‐bending scope, showed that it was useful for obtaining a direct en face view of the lesser curvature of the body of the stomach, and an increase in the rate of one‐time complete resection was seen when it was used.     

Endoscopic mucosal resection: not only therapeutic, but a diagnostic procedure for sessile gastric polyps

Background and Aims: Histological examination of specimens obtained by forceps biopsy sampling of gastric lesions is of limited accuracy, and their management on this basis is therefore controversial. Endoscopic mucosal resection (EMR) was initially developed in Japan for the resection of early gastric cancer (EGC). The potential use of EMR as a diagnostic tool has been suggested. The aims of the present study were to assess the value of forceps biopsy sampling in establishing the correct diagnosis revealed by EMR and to evaluate the efficacy of EMR. Methods: Fifty‐six subjects with sessile gastric polyps of epithelial origin, at least 0.5 cm in diameter, and not associated with polyposis syndromes, were included. Following forceps biopsy sampling, EMR was performed with an inject‐and‐cut technique or with cap‐fitted methods. The histological results on the forceps biopsy and the resected specimens were analyzed. Results: Histology on the resected specimens revealed neoplastic lesions in 34 cases, including seven EGC, and there were hyperplastic‐inflammatory lesions in 21 cases. Complete agreement between the previous histological results of the forceps biopsy samples and the resected specimens was seen in only 76.7% of the lesions. Altogether, the sensitivity and specificity of the forceps biopsy procedure for diagnosing neoplastic lesions were 87.5% (95% confidence interval [CI] = 76.0–98.9%) and 65.2% (95% CI = 45.7–84.7), respectively. A clinically relevant discrimination between neoplastic and non‐neoplastic lesions was not achieved in seven cases. No complications, such as perforation or massive bleeding necessitating surgical treatment, were encountered. EMR was considered complete in five patients. None of the EGC recurred during the mean 38‐month (6–72) follow up. Conclusions: Forceps biopsy is not fully representative of the entire lesion, and a simple biopsy may therefore lead to a faulty differentiation between neoplastic and non‐neoplastic lesions. EMR proposes diagnostic and staging advantage in assessing patients with EGC as compared to forceps biopsy, because it provides more intact mucosa and submucosa for histological analysis. Sessile gastric polyps should be fully resected by EMR for a final diagnosis and (depending on the lesion size and type) possibly definitive treatment.     

Key factors for successful en bloc endoscopic submucosal dissection of early stage gastric cancer using an insulation-tipped diathermic knife

BACKGROUND/AIMS: En bloc endoscopic mucosal resection (EMR) is presently considered to be the treatment of choice for endoscopically resectable early stage gastric cancer (EGC). Although a new EMR technique using an insulation-tipped diathermic knife (endoscopic submucosal dissection using an IT knife: IT knife-ESD) is reportedly suitable for en bloc resection, a failure in en bloc resection (piecemeal resection) can occur. We retrospectively analyzed factors affecting the success rate of en bloc resection by IT knife-ESD. METHODOLOGY: A total of 71 gastric lesions were treated by IT knife-ESD. En bloc/piecemeal resection rates were investigated. Twelve potential factors associated with clinicopathological characteristics or procedures were analyzed univariately and multivariately. RESULTS: IT knife-ESD was successfully performed in all 71 lesions. En bloc resection was achieved in 63 lesions (91%), while eight lesions (9%) were removed as two or more fragments (piecemeal resection). The multivariate analysis identified only one independent factor affecting the success rate of en bloc resection: the second-half period of procedure application. The en bloc resection rate was not associated with the tumor location/site, tumor size, specimen size, and ulceration within the tumor. CONCLUSIONS: Much experience with IT knife-ESD may resolve the tumor-related technical difficulties. It is true for this advanced procedure that endoscopist experience is highly likely to be a critical factor for treatment success. We consider that IT knife-ESD for EGC is feasible and safe when performed by experienced endoscopists.     

Treatment modalities for early gastric cancer

Different treatment modalities have been proposed in the treatment of early gastric cancer (EGC). Endoscopic resection (ER) is an established treatment that allows curative treatment, in selected cases. In addition, ER allows for an accurate histological staging, which is crucial when deciding on the best treatment option for EGC. Recently, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have become alternatives to surgery in early gastric cancer, mainly in Asian countries. Patients with “standard” criteria can be successfully treated by EMR techniques. Those who meet “expanded” criteria may benefit from treatment by ESD, reducing the need for surgery. Standardized ESD training system is imperative to promulgate effective and safe ESD technique to practices with limited expertise. Although endoscopic resection is an option in patients with EGC, surgical treatment continues to be a widespread therapeutic option worldwide. In this review we tried to point out the treatment modalities for early gastric cancer.     

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.     

Endoscopic mucosal resection of early gastric cancer： Experiences in Korea

Endoscopic mucosal resection （EMR） has been established as one of the treatment options for early gastric cancer （EGC）. However, there are many uncertain areas such as indications of EIR, best treatment methods, management of complications and follow-up methods after the procedure. Host studies on this topic have been carried out by researchers in Japan. In Korea, gastric cancer is the most common malignant disease, and the second leading cause of cancer death. In these days, EIR for EGC is widely performed in many centers in Korea. In this review, we will provide an overview of the bechniques and outcomes of EIR in Korea.     

Is endoscopic one‐piece mucosal resection essential for early gastric cancer?

Background: Endoscopic mucosal resection (EMR) is widely accepted as a minimally invasive treatment for early gastric cancer (EGC) in Japan. However, the criteria for EMR must be strictly adhered to otherwise patients will miss the chance for additional therapy. We assess the important factor in expanding the indication of EMR. Methods: We investigated 1101 EGCs that had been resected by EMR at the National Cancer Center Hospital (NCCH), Tokyo, Japan, according to the indication recommended by Japanese Gastric Cancer Association (JGCA) and the expanded indication proposed by NCCH. Curability and local recurrence of the EMRs were assessed related to the applied indication and the number of resected specimens. Results: The recurrence rate of non‐evaluable resection was higher than that of evaluable resection (P < 0.0001). Eighty‐three lesions among 772 lesions in the JGCA group were non‐evaluable. Thirty‐seven leisons among 329 lesions in the NCCH group were non‐evaluable. There was no difference in the rate of non‐evaluable resection between JGCA and NCCH groups (P = 0.8329). However, the rate of curative resection was lower in the NCCH group than in the JGCA group (P = 0.0009). In piecemeal resection, there was no difference in the rate of non‐evaluable resection between JGCA and NCCH groups (P = 0.0527). In one‐piece resection, the rate of non‐evaluable resection was lower in the NCCH group than the JGCA group (P = 0.0137). Conclusion: Based on our series of cases, we propose one‐piece resection as a gold standard for EMR because it enables accurate histological evaluation, even in the EMR, according to the expanded indication.     

Outcome after endoscopic submucosal dissection for early gastric cancer in Korea

Endoscopic treatment,such as endoscopic mucosal resection(EMR) and endoscopic submucosal dissection(ESD),has been established as one of the treatment options for selected cases with early gastric cancer(EGC).Most studies on this topic have been carried out by researchers in Japan.Recently,the experience in EMR/ESD for EGC outside Japan is increasingly reported.In Korea,gastric cancer is the most common malignant disease,and the second leading cause of cancer death.Currently,EMR for EGC is widely performed i...     

ENDOSCOPIC SUBMUCOSAL DISSECTION WITH SHEATH‐ASSISTED COUNTER TRACTION FOR EARLY GASTRIC CANCERS

Aim: Endoscopic submucosal dissection (ESD) is associated with frequent complications, such as bleeding and perforation. The procedure is technically difficult, requires considerable skill and is longer than conventional endoscopic mucosal resection (EMR). Thus, non‐invasive tools and methods are needed to facilitate direct visualization of the submucosal layer during ESD. Methods: An insulation‐tipped (IT) knife was inserted into one channel, and a conventional injection sheath was inserted to the other channel of a double‐channel fiberscope. The submucosal layer was lifted via a circumferential incision using the conventional injection sheath for visualizing cutting lines, and the submucosal layer under the lesion was directly dissected from the underlying muscularis propria. Results: Sheath‐assisted traction resulted in successful ESD with en bloc resection in all 25 patients. Hemostasis and manipulation of blood vessels were uncomplicated and dissection was completed safely, without either bleeding or perforation. The movement of the sheath was not suppressed while lifting the submucosal layer and the IT knife could be moved freely, which allowed submucosal dissection independently of the sheath movement. Conclusion: Sheath‐assisted traction ESD, using simple materials and methods, has several advantages over other standard traction methods. Our procedure is straightforward, safe, non‐invasive, cost‐effective and uses readily available instruments to enhance visualization of cutting lines.     

Factors affecting long-term clinical outcomes of endoscopic mucosal resection of early gastric cancer

BACKGROUND/AIMS: Endoscopic mucosal resection (EMR) has been widely accepted as a treatment option for early gastric cancer (EGC) in selected cases. The purposes of this study were to evaluate the long-term outcomes and the factors affecting the clinical outcomes, of EMR performed in EGC. METHODOLOGY: Between April 1996 and March 2005, 147 patients have undergone EMR to treat EGC at Yonsei University Medical Center, Seoul, Korea. We assessed the clinical outcomes of the EMR for EGC in a long-term follow-up period. We also reviewed the medical records of the patients including demographic data, endoscopic characteristics of the lesion and histopathologic findings. RESULTS: The histopathologic evaluations after the EMR treatment showed that overall complete resection rate was 84.6% (126/149) while complete resec tion rate of 93.5% was achieved in mucosal cancers (115/123). The success of complete resection was significantly affected by endoscopic gross type (depressed lesion), the degree of differentiation, and the depth of invasion, independently. There were only 5 cases of local recurrence during the follow-up periods, and the recurred or incompletely resected lesions were successfully treated by salvage operation or endoscopic retreatment. There was no disease-related or treatment-related mortality during the follow-up period. CONCLUSIONS: EMR is a good and safe curative treatment option with feasible clinical outcomes in patients with EGC. It must be emphasized that a proper selection of candidates is mandatory to improve the clinical outcome of EMR in EGC.     

Endoscopic submucosal dissection for early gastric cancer and gastric adenoma]

BACKGROUND/AIMS: Endoscopic Submucosal Dissection (ESD) is a new endoscopic mucosal resection (EMR) technique which enables en bloc resection even in large and depressed lesions. The aims of this study were to assess the therapeutic efficacy and the safety of ESD in gastric adenoma and in early gastric cancer (EGC). METHODS: We analyzed 101 lesions in 101 patients. ESD with insulated-tipped (IT) knife were performed in 52 adenomas and 49 EGCs from January 2003 to December 2005 in Dong-A University Hospital. RESULTS: The mean size of the lesion was 2.58 cm (0.7-4.5 cm). En bloc resection rate was 90.1% which was influenced by size (p0.05). Complete resection rate was 83.2% even in large or in malignant tumors (p0.05). Bleeding after ESD occurred in 41.6%. Tumor recurrence rate was 2.0%. CONCLUSIONS: ESD with IT knife is effective for the treatment of EGC and gastric adenoma even in large or in malignant lesions without definite increased risk of complications.     

EMR for early gastric cancer in Korea: a multicenter retrospective study

BACKGROUND: EMR has been accepted as a treatment modality for selected cases of early gastric cancer (EGC) in Japan. However, long-term outcomes after EMR for EGC have not been fully documented. OBJECTIVES: We reviewed the experiences of EMR for EGC in Korea, with emphasis on the long-term outcome. DESIGN: Multicenter, retrospective study. METHODS: Data were collected retrospectively by use of the on-line database registry system. From January 2000 to December 2002, 514 EGCs in 506 patients were treated by EMR in 13 institutions in Korea. Median age of the patients was 60 years (range 45-83 years). The resection was regarded as incomplete if histopathologic examination revealed a positive resection margin or submucosal invasion or positive lymphovascular invasion or undifferentiated histologic diagnosis. RESULTS: The most commonly used technique was circumferential precutting followed by snare resection (EMR-P, n = 269, 52.3%). Complete resection and incomplete resection after EMR were confirmed in 399 lesions (77.6%) and 103 lesions (20.0%), respectively. For completely resected mucosal cancers (n = 399), the median duration of follow-up was 23.5 months (range 5-70 months). In this group, local recurrence was detected in 24 cases (6.0%) with a median interval between EMR and recurrence of 17.9 months (range 3.5-51.7 months). There were 3 cases with perforation and 71 cases with bleeding. No deaths were related to recurrence of gastric cancer during the overall median follow-up period of 39 months. LIMITATIONS: Multicenter retrospective design, no controls. CONCLUSIONS: EMR is an effective therapeutic modality for selected cases of EGC in Korea.     

CLINICAL USEFULNESS OF HIGH‐FREQUENCY ULTRASOUND PROBES FOR NEW INVASION DEPTH DIAGNOSIS IN SUBMUCOSAL COLORECTAL CARCINOMA

Recently it has become very important to diagnose more precisely the invasion depth of submucosal carcinoma prior to endoscopic mucosal resection (EMR) whether selecting lesion is with or without indications for EMR. This study aimed to evaluate the usefulness of high‐frequency ultrasound probes (HFUP) for preoperative diagnosis of vertical invasion depth < 1000 µm or not in superficial and sessile type submucosal colorectal carcinomas. Twenty‐seven cases of superficial and sessile type submucosal colorectal carcinoma were examined with high‐frequency ultrasound probes (HFUP; 15 or 20 MHz radial‐scan ultrasound probes; Olympus Optical, Tokyo, Japan and Fujinon Omiya, Saitama, Japan) at Hiroshima University Hospital and analyzed. Diagnostic accuracy was confirmed by comparing the ultrasonic with the pathologic vertical invasion depth of specimens resected either by EMR or surgical resection. Histologic depth of submucosal invasion was defined as the distance from muscularis mucosae measured microscopically with a micrometer. When muscularis mucosae in the tumor could not be detected, we measured the invasion depth from the surface of the carcinoma to the apex of the deepest invasive portion. As a result, invasion depth between ultrasonic image and histologic findings showed a significantly close correlation. HFUP diagnosis was demonstrated as useful in determining the distance of vertical invasion and for planning a therapeutic strategy against submucosal colorectal carcinomas.     

High en bloc resection rate achieved by endoscopic mucosal resection with IT knife for early gastric cancer

BACKGROUND/AIMS: Circumferential endoscopic mucosal resection (EMR) around lesions performed by an insulation-tipped diathermic knife (IT knife) increases en bloc resection rates, suggesting the possibility of expanding indications for EMR. METHODOLOGY: Clinical outcome of EMR performed by IT knife under general anesthesia was evaluated for 26 patients with 29 early gastric cancer. RESULTS: Successful en bloc resection rates obtained by the IT knife were 100, 87.5, 90.0 and 100% for lesions < or =10 mm in size, 11-20 mm, 21-30 mm, and > or =31 mm, respectively. They were significantly higher with the IT knife than those obtained by the conventional method (IT knife method: 93.1% vs. conventional method: 28.5%, p<0.0001). Two lesions were lateral margin positive, and in three cases invasion of lesions was observed as deep as the submucosa. Distal, total, and proximal gastrectomy with D2 lymphadenectomy, respectively, was provided in 3 cases; however, no lymph node involvement was found in any of the resected specimens. Bleeding and perforation were observed in 3 cases, respectively, however, no additional surgical treatment was required for these patients. CONCLUSIONS: EMR by means of the IT knife under general anesthesia can be performed safely and adequately. It is a useful treatment modality for early gastric cancer.     

Endoscopic submucosal dissection allows curative resection of locally recurrent early gastric cancer after prior endoscopic mucosal resection

BACKGROUND: Repeat endoscopic mucosal resection (EMR) to cure locally recurrent early gastric cancer (EGC) is difficult to perform because the initial EMR causes submucosal fibrosis; however, ESD allows submucosal dissection through the fibrosis and provides an en bloc specimen. OBJECTIVE: The objective was to determine the safety and efficacy of ESD and compare the results to historical controls. DESIGN: This was a retrospective, case-control study. PATIENTS: We used our prospectively entered database (1993-2003) to identify 64 patients who had locally recurrent EGC after EMR. MAIN OUTCOME MEASUREMENTS: We defined the resections as curative when the lateral and vertical margins were free of cancer and repeat endoscopy showed no recurrent disease. RESULTS: Among 46 patients who underwent ESD, 41 (89.1%) en bloc resections were achieved compared to none in 18 conventional procedures (P < .0001). The specimen of 1 lesion (2.4%) out of 41 en bloc resections was histologically nonevaluable, compared with 10 lesions (43.4%) in 23 piecemeal resections (P < .0001). Three residual tumors (27.3%) were found in the 11 nonevaluable specimens. Three perforations occurred during ESD; all were successfully treated endoscopically with endoclips. LIMITATIONS: The limitation of the study was retrospective design. CONCLUSIONS: ESD provides high en bloc resection rate for locally recurrent EGC after previous EMR. In turn, en bloc resections allow precise histological staging to be assessed and prevent residual disease and recurrence.     

Factors affecting complete resection of gastric tumors by the endoscopic mucosal resection procedure

BACKGROUND: In Japan, endoscopic mucosal resection (EMR) has been widely used as a treatment option for small early gastric cancer (EGC). The present study reviewed 178 cases for the 10-year period 1987-1997 in order to clarify the factors affecting the successful outcome of EMR. METHODS: Logistic regression analysis was used to examine whether complete resection of EGC correlated with the patient's age, gender, the characteristics of the tumor (location, macroscopic form, and size), the duration of the procedure and the experience of the doctor. RESULTS: The location of the tumor and the duration of the procedure correlated with the completeness of the resection (P < 0.01 and P < 0.05, respectively). Endoscopic mucosal resection was more difficult to perform for tumors in the gastric body than in the antrum or incisura region, and the longer the procedure the less complete the resection. CONCLUSION: The outcome of EMR is affected significantly by the location of the EGC.