USE OF SHORT NEEDLE KNIFE FOR ESOPHAGEAL ENDOSCOPIC SUBMUCOSAL DISSECTION

Background: The emergence of endoscopic submucosal dissection (ESD) has enabled en bloc resection of lesions, which were conventionally difficult. However, ESD has problems of technical difficulty and high incidence of complications. In order to improve the procedure of marking and submucosal dissection in the esophagus, we modified and adjusted the standard needle knife to a short needle knife having a tip portion with a projection length of 1.5 mm. Methods: We treated 20 esophageal lesions with ESD using the short needle knife. We marked around the lesion with the short needle knife and performed mucosal incision of the entire circumference with a needle knife and an IT knife, then dissected the submucosal layer with the short needle knife. A Hook knife was also used in situations where muscular layers were located in the front‐view Results: Complete en bloc resection was performed in all 20 cases. The diameter of lesions ranged from 3 to 65 mm (median, 20 mm), and that of resected specimens ranged from 28 to 90 mm (median, 47 mm). Submucosal dissection was completed with the short needle knife alone in 13 cases in 20 (65%), and in seven cases (35%), in combination with so‐called Hook knife. The procedure was complicated in one patient with mediastinal emphysema. Conclusions: The short needle knife proved to be useful and safe in clear marking and submucosal dissection of esophageal lesions. It allows greater flexibility in the angle of insertion, and enables more effective and safer procedures because its full length can be inserted into the submucosa and fixed.     

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.     

INTRAOPERATIVE BLEEDING IN ENDOSCOPIC SUBMUCOSAL DISSECTION IN THE STOMACH AND STRATEGY FOR PREVENTION AND TREATMENT

To control intraoperative bleeding is an important key to successful endoscopic submucosal dissection. The distribution of submucosal vessels encountered during the procedure differ in places in the stomach and are roughly categorized into three groups: those located in the antrum, those in the lesser curvature, and those on the anteroposterior corpus wall which consists of oblique muscle layers. Therefore, knowledge of a suitable setting of diathermy and adjusted depth of dissection in the submucosal layer for each site is imperative. The combination of utilizing the distal attachment forced or swift coagulation (trimming with coagulation mode) have enable the treatment with an insulation tipped knife safer.     

HEMOSTASIS WITH HOOK KNIFE DURING ENDOSCOPIC SUBMUCOSAL DISSECTION

Major complications reported with endoscopic submucosal dissection are bleeding and perforation. The most important step in preventing such complications is to maintain visualization of the submucosal layer. The hook knife is not only a useful cutting device for submucosal dissection, but the device also provides effective means for hemostasis and prevention of bleeding during endoscopic submucosal dissection. Vessels with a diameter of 1 mm or less do not bleed if cut with a hook knife using spray mode coagulation.     

Microvasculature of the esophagus and gastroesophageal junction: Lesson learned from submucosal endoscopy

Advanced therapeutic endoscopy,in particular endoscopic mucosal resection,endoscopic submucosal dissection,per-oral endoscopic myotomy,submucosal endoscopic tumor resection opened a new era where direct esophageal visualization is possible.Combining these information with advanced diagnostic endoscopy,the esophagus is organized,from the luminal side to outside,into five layers(epithelium,lamina propria with lamina muscularis mucosa,submucosa,muscle layer,adventitia).A specific vascular system belonging to each layer is thus visible: Mucosa with the intra papillary capillary loop in the epithelium and the sub-epithelial capillary network in the lamina propria and,at the lower esophageal sphincter(LES) level with the palisade vessels; submucosa with the drainage vessels and the spindle veins at LES level; muscle layer with the perforating vessels; periesophageal veins in adventitia.These structures are particularly important to define endoscopic landmark for the gastro-esophageal junction,helpful in performing submucosal therapeutic endoscopy.     

RISK MANAGEMENT IN ENDOSCOPIC SUBMUCOSAL DISSECTION USING NEEDLE KNIFE IN KOREA

The needle knife is used for mucosal incision during endoscopic mucosal resection (EMR). The first author has used the needle knife for EMR since 1996 to overcome several limitations. Conventional EMR is not able to be used to remove tumors >15 mm. Excessive burning effect on the margin during strip biopsy leads to misdiagnosis during evaluation of resection margins. Relatively larger specimens could be resected and resection margins evaluated effectively with EMR with needle knife. Nowadays the needle knife is used to perform endoscopic submucosal dissection (ESD) from mucosal incision to submucosal dissection. The advantages of needle knife are as follows: (i) the lumen of the stomach can be kept clear during the whole procedure because of less burning effect; (ii) the procedure time for ESD is short because the needle knife has a very thin body, enabling the mucosal and submucosal layer to be cut quickly; and (iii) the needle knife can provide cutting action with the tip. In contrast, the needle knife has a high potential to cause perforation during incision and dissection. Only experts can use the needle knife safely. The perforated site can be closed endoscopically using hemoclips. To prevent perforation the needle knife should be kept parallel to the gastric wall during dissection. In conclusion, the needle knife has many advantages as well as a higher risk of perforation. However, the success rate for ESD using the needle knife increases with sufficient experience.     

Current opinions for endoscopic submucosal dissection for colorectal tumors from our experiences: indications, technical aspects and complications

Endoscopic submucosal dissection (ESD) was first applied in the resection of large colorectal tumors 10 years ago. Frequent complications and technical difficulties were serious problems at first, but were gradually improved with experience. Here, we describe the indications, technical aspects and management of complications of ESD for colorectal tumors. In 2009, we introduce the use of small tip insulation-tipped diathermic (IT) knife. Features separating it from the IT knife and IT Knife2 are a smaller ceramic tip and small round disk at the root of the tip. During submucosal dissection, the small tip IT knife could dissect large pieces of tissue intact. This allows us to shorten the procedure time, particularly the submucosal dissection component. A total of 146 ESD for 140 patients were performed between January 2009 and July 2011. En bloc, and en bloc and R0 resection rates were 92.5% and 83.6%, respectively. Median procedural time was 48.5 min for 40.5 mm specimens. Perforation and delayed bleeding occurred in 2.1% and 1.4%, respectively. We successfully performed ESD for colorectal tumors with a shortened procedure time while preserving quality and safety.     

Technique of the double-channel ESD method performed with an EEMR tube

Endoscopic submucosal dissection (ESD) recently has been aggressively performed to treat superficial esophageal cancer; however, it is difficult to secure a good field of view for mucosal dissection, and the technique requires considerable skill. We have developed a double-channel ESD method using an endoscopic esophageal mucosal resection (EEMR) tube that makes it possible to perform the submucosal dissection with a good field of view while applying countertraction. Countertraction is achieved by maneuvering a fine grasping forceps inserted through the side channel of the EEMR tube, and the field of view of the submucosal dissection layer can be easily exposed. This technique can be performed while constantly observing the submucosal dissection layer with a stable field of view, and it is also easy to handle the blood vessels. Moreover, there is no disturbance of the field of view by the dissected mucosa.     

A novel method of endoscopic submucosal dissection with blunt abrasion by submucosal injection of sodium carboxymethylcellulose: an animal preliminary study

BACKGROUND: Endoscopic submucosal dissection (ESD), particularly the process of submucosal incision with a knife, is technically difficult and carries a high risk of perforation. Submucosal injection of a viscous substance, eg, jelly, obviates the need of submucosal incision with a knife. Sodium carboxymethylcellulose (SCMC), known as cellulose gum, is highly viscous when dissolved in water. OBJECTIVE: To evaluate the efficacy and the safety of ESD by submucosal injection of SCMC solution in a porcine stomach. DESIGN AND SETTING: A prospective, single-center study. INTERVENTIONS: The viscosity of various concentrations (0.5%-3.5%) of SCMC was measured by a viscometry. First, we injected 10 mL of various concentrations of SCMC solution into the submucosal layer of resected porcine stomachs in vitro and examined whether the submucosal injection dissected the mucosal layer from the muscular layer by EUS. Second, we performed ESD by injecting, with an 18-gauge needle, the SCMC solution into the submucosal layer of the stomach in white domestic pigs in vivo to evaluate the efficacy and the safety of SCMC for ESD. MAIN OUTCOME MEASUREMENTS AND RESULTS: Submucosal injection of the SCMC solution dissected most of the mucosal layer from the muscular layer at the concentration above 2.0%. We, therefore, decided to use 2.5% SCMC for ESD with a 18-gauge needle to ensure dissection. Submucosal injection of 2.5% SCMC dissected the mucosal layer from the muscular layer without complications, such as massive bleeding or perforation, in white domestic pigs. Histologically, injection of 2.5% SCMC revealed no damage to the muscular layer and surrounding tissue. LIMITATIONS: Our novel injection technique was evaluated in an animal model with a normal stomach; it was relatively easy to approach the target mucosa. CONCLUSIONS: ESD by submucosal injection of viscous SCMC solution appeared to be an easy, safe, and technically efficient method for dissection of gastric lesions.     

ENDOSCOPIC MUCOSAL RESECTION FOR EARLY GASTRIC CANCER: A NEW TECHNIQUE USING A SLIT‐HOOD and HOOK KNIFE

We report a successful application of a new submucosal dissection method for EMR using an endoscope equipped with a slit‐hood and hook knife. The mucosal lesion is separated from the submucosal layer with the aid the hood and the submucosal fibers are cut with the hook knife introduced through the slit, allowing an easy and safe dissection with good visualization of the tissue. Twenty‐seven patients with early gastric cancer underwent EMR using a slit‐hood and hook knife. Tumors were completely resected in 10 cases, and perforation of the stomach occurred in one case. The hook knife cuts as it is pulled back into the hood, helping to prevent perforation.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR GASTRIC SUBMUCOSAL TUMOR,ENDOSCOPIC SUB‐TUMORAL DISSECTION

Gastric submucosal tumor (SMT) is frequently found during screening endoscopy, but definitive diagnosis based on histological confirmation is relatively difficult. Even without accurate diagnosis before treatment, open or laparoscopic surgery is currently carried out to remove SMT. The purpose of this study was to demonstrate the feasibility of endoscopic submucosal dissection (ESD) in diagnostic treatment for submucosal tumor (SMT) of the stomach. Subjects in this case study comprised nine patients who had undergone ESD for gastric SMT. Before treatment, endoscopic ultrasonography was carried out in all cases to evaluate depth and origin of the SMT. Then ESD was only indicated for tumors of submucosal layer or muscularis mucosa origin. Using an endoscopic sub‐tumoral dissection technique with a hook knife and a flex knife, local complete resections were achieved in all patients without severe complications. These results suggest the clinical benefits of ESD avoiding oversurgery for the diagnostic treatment of gastric SMT of the submucosal layer and muscularis mucosa origin.     

Advantages of endoscopic submucosal dissection over conventional endoscopic mucosal resection

BACKGROUND: Endoscopic mucosal resection is an established method for treating intramucosal gastric neoplasms. Conventional endoscopic mucosal resection has predominantly been performed using strip biopsy, but local recurrence sometimes occurs due to such piecemeal resection. Endoscopic submucosal dissection has recently been performed in Japan using new devices such as an insulation-tip diathermic knife. The efficacy and problems associated with endoscopic submucosal dissection were evaluated by comparison with conventional endoscopic mucosal resection. METHODS: Treatment consisted of conventional endoscopic mucosal resection for 48 lesions from January 1999 to October 2002, and endoscopic submucosal dissection for 59 lesions from November 2002 to June 2005. Endoscopic submucosal dissection was performed using an insulation-tip diathermic knife and flex and hook knives, as appropriate. RESULTS: For lesions >or=11 mm in size, en bloc resection rates were significantly higher with endoscopic submucosal dissection than with conventional endoscopic mucosal resection, but treatment time was significantly longer. En bloc resection rates were higher with endoscopic submucosal dissection than with conventional endoscopic mucosal resection in all areas. Treatment of lesions in the upper one-third of the stomach took a long time using endoscopic submucosal dissection, and intraoperative bleeding was frequent. However, en bloc resection rates and intraoperative bleeding with endoscopic submucosal dissection were improved using various knives. CONCLUSIONS: Endoscopic submucosal dissection can take a long time, but is superior to conventional endoscopic mucosal resection for treating intramucosal gastric neoplasms.     

TECHNIQUES AND PITFALLS OF ENDOSCOPIC SUBMUCOSAL DISSECTION FOR COLORECTAL TUMORS

Endoscopic submucosal dissection (ESD) for colorectal tumors is steadily being developed. Safety and standardization of ESD for colorectal tumors have not been yet established because of the technical difficulties and the unsuitable anatomical characteristics of the colon and rectum. The authors mainly use a Flex knife for mucosal incision and a Hook knife for submucosal dissection to perform ESD safely. Skillful colonoscopic control, selection of scope, distal attachment tip hood, adequate high‐frequency generator and correct approach strategy should all be considered for safe performance of ESD. However, the incidence of indicative lesions is rare because the majority of colorectal tumors are adenomatous large laterally spreading tumors, which can be cured by intentional endoscopic piecemeal resection. At present, ESD for colorectal tumors should be performed only at central facilities that have expert colonoscopists. With the development of new devices and associated techniques, technical standardization of ESD for colorectal tumors is expected in the near future.     

Pattern of lymph node metastases of esophageal squamous cell carcinoma based on the anatomical lymphatic drainage system

The recent anatomical studies of the esophagus showed that submucosal longitudinal lymphatic vessels connect to the superior mediastinal and the paracardial lymphatics and lymphatic routes to periesophageal nodes originate from the muscle layer. Using clinical data for lymph node metastasis, we verify these anatomical bases to clarify the rational areas of lymph node dissection in esophageal cancer surgery. Analysis was performed on 356 consecutive patients who underwent esophagectomy with three‐field dissection. Patients were divided into those with tumor limited within the submucosal layer and those with tumor invading or penetrating the muscle layer. Frequency of node metastasis was compared according to supraclavicular, upper mediastinum, mid‐mediastinum, lower mediastinum, perigastric and celiac areas. In patients with tumor limited to the submucosal layer, node metastasis was more frequent in the upper mediastinum and perigastric area than the mid‐ or lower mediastinum. Even in patients with tumor located in the lower esophagus, node metastasis was more frequent in the upper mediastinum than the mid‐mediastinum or lower mediastinum. In patients with tumor located in the mid‐esophagus, node metastasis was more frequent in the supraclavicular area than the mid‐mediastinum or lower mediastinum. In patients with tumor invading or penetrating the muscle layer, node metastasis in the mid‐ and lower mediastinum increased dramatically, but was still less frequent than those in the upper mediastinum or the perigastric area. Postoperative survival curves did not differ among the involved areas. The most predictive factor associated with lymph node metastasis for postoperative survival was not the area of involved nodes, but the number of involved nodes by multivariate analyses. These clinical results verify recent anatomical observations. The lack of difference in survival rates among the involved areas suggests that these areas should be staged equivalently. For adequate nodal staging, the upper mediastinum should be dissected for the lower esophageal tumor and supraclavicular areas should be dissected for the mid‐esophageal tumor even in patients with tumor limited to within the submucosal layer.     

Submucosal tunnelling endoscopic resection for the treatment of esophageal submucosal tumours originating from the muscularis propria layer: An analysis of 15 cases

Background and aimsThe aim of this prospective study was to evaluate the feasibility of submucosal tunnelling endoscopic resection of esophageal tumours originating from the muscularis propria layer.MethodsFifteen patients with esophageal submucosal tumours originating from the muscularis propria layer underwent submucosal tunnelling endoscopic resection between August 2011 and February 2012. The key steps were: (1) creating a submucosal tunnel from 5 cm above the tumour between the submucosal and muscular layers with a hook knife or hybrid knife; (2) dissecting the tumour by the technique of endoscopic submucosal dissection; (3) closing the mucosal incision site with clips after the tumour was removed.ResultsSubmucosal tunnelling endoscopic resection was successfully performed in all cases. The en bloc resection rate was 100%. The average tumour diameter was 1.8 cm (range 1.0–3.0 cm). During the procedure, perforation occurred in 3 patients, who recovered after conservative treatment. No residual tumour or tumour recurrence was detected during the follow-up period (mean: 3.5 months, range: 1–9 months). Pathological diagnoses of these tumours were leiomyomas (12/15) and gastrointestinal stromal tumours (3/15).ConclusionsSubmucosal tunnelling endoscopic resection is a feasible method for the treatment of small esophageal submucosal tumours originating from the muscularis propria layer.     

Usefulness and safety of SB knife Jr in endoscopic submucosal dissection for colorectal tumors

Use of a Dual knife has become commonplace for endoscopic submucosal dissection (ESD) of colorectal tumors at Hiroshima University Hosipital. A Hook knife has been also used in combination with the Dual knife, depending on the location of the lesion. We have had recent opportunities to use a scissors-type SB knife Jr. We retrospectively compared outcomes of colorectal ESD performed with the Dual knife in combination with the SB knife Jr versus the Hook knife. In conclusion, although the Hook knife was shown to be a very useful auxiliary device for colorectal ESD, the SB knife Jr. yielded better results than the Hook knife in terms of complete en block resection and avoidance of perforation. Use of the Dual knife with the SB Knife Jr shows good potential for improving complete en bloc resection rate and safety of technically difficult colorectal ESD.     

MANAGEMENT OF BLEEDING CONCERNING ENDOSCOPIC SUBMUCOSAL DISSECTION WITH THE FLEX KNIFE FOR STOMACH NEOPLASM

Management of bleeding is crucial for a successful endoscopic submucosal dissection (ESD) with the Flex knife for a stomach neoplasm. Medical approaches to suppress gastric acid secretion and keep systolic blood pressure at the level of < 150 mmHg during ESD are tried to lessen bleeding. But, major concerns for bleeding are whether the blood vessels are cut off or not and endoscopic surgeons have to avoid blind application of devices for ESD as much as possible. Even in the situations where blind application for non‐visible vessels in the submucosa is not preventable such as in the steps of marking, submucosal injection, mucosal incision, and snaring, the efforts to lessen bleeding are necessary. When non‐bleeding visible vessels are noticed, ‘prebleeding coagulation’ with appropriate devices is important. Even if unexpected bleeding occurs, it is also controllable using appropriate devices according to the type of bleeding. All endscopists who perform ESD should also be experts in management of bleeding.     

NOVEL TECHNIQUE OF ENDOSCOPIC SUBMUCOSAL DISSECTION USING AN EXTERNAL GRASPING FORCEPS FOR SUPERFICIAL GASTRIC NEOPLASIA

Endoscopic submucosal dissection (ESD) for early stage gastric cancer (EGC) has improved the success rate of en bloc resection but results in perforation more often than does endoscopic mucosal resection. We report a novel technique of ESD using an external grasping forceps. A total of 265 lesions with EGC or gastric adenoma were enrolled in this study. Sixteen lesions were located in the upper third portion of the stomach, 114 in the middle third portion, and 135 in the lower third portion. After submucosal injection followed by circumcision of the lesions with a flex knife, the external grasping forceps was introduced with the help of a second grasping forceps and anchored at the margin of the lesion. Oral traction applied with this forceps could elevate the lesion and make the submucosal layer wider and more visible, thereby facilitating dissection of the submucosal layer under direct vision. The mean lesion size was 15.0 mm (range: 5–50 mm). All but 11 lesions (95.8%) could be resected en bloc with free margins. Mean procedure time was 45 min (range: 20–180 min). It was difficult to carry out this procedure when the lesions were located in the cardia, lesser curvature, or posterior wall of the upper third of the gastric body. Bleeding after ESD occurred in 10 patients (3.8%) and perforation occurred in one patient (0.4%). The endoscopic submucosal dissection using an external grasping forceps for superficial gastric neoplasia is efficacious and safe.     

NEW DEVICE TO PERFORM COAGULATION AND IRRIGATION SIMULTANEOUSLY DURING ENDOSCOPIC SUBMUCOSAL DISSECTION USING AN INSULATION‐TIPPED ELECTROSURGICAL KNIFE

Background: Although bleeding is an unavoidable complication of endoscopic submucosal dissection (ESD), endoscopic hemostasis using an insulation‐tipped electrosurgical knife (IT) knife is impossible because an insulator is mounted at the tip of the knife. We have developed a new type of hood which could perform both coagulation and irrigation simultaneously. Methods: Our new device was fabricated by drilling a side hole in the cap portion of a conventional transparent hood followed by attaching a machined papillotomy knife to the exterior surface of the hole. Results: Our new hood was useful for hemorrhage during ESD using IT knife. Conclusions: With this method, endoscopic hemostasis using IT knife is easy, as hemostatic procedure can be performed under irrigation and coagulation using conventional endoscopy.     

Endoscopic submucosal dissection with insulated-tip knife for large mucosal early gastric cancer: a feasibility study (with videos)

BACKGROUND: According to clinicopathologic studies, differentiated-type mucosal early gastric cancers without ulcer or ulcer scar have little risk of lymph-node metastasis, irrespective of tumor size. However, patients with large mucosal early gastric cancer have been subjected to surgery because conventional EMR methods could not resect large tumors en bloc. OBJECTIVE: To evaluate the feasibility and the efficacy of endoscopic submucosal dissection for treatment of early gastric cancers larger than 3 cm in diameter. DESIGN: Case series study. SETTING: Referral cancer center. PATIENTS: A total of 30 consecutive patients were enrolled with the following characteristics: diagnosis of differentiated-type early gastric cancer larger than 3 cm, lack of ulcerative change, no endoscopic evidence for submucosal invasion, and no evidence of lymph-node or distant metastasis (22 men and 8 women; median age, 69 years; median tumor size, 40 mm). INTERVENTIONS: Tumors were resected by endoscopic submucosal dissection with an insulated-tip knife. MAIN OUTCOME MEASUREMENTS: Complete resection, complication rate, and operation time. RESULTS: Complete resection was obtained in 23 of 30 cases (77%). Complications included hemorrhage (n=4), perforation (n=1), and pyloric stenosis (n=1), but no severe complications occurred that required surgery or that led to major morbidity. Complete resection and complication rates improved in the last 10 cases (90% and 0%, respectively), though operation time was not shortened. LIMITATIONS: Small sample size and lack of controls. CONCLUSIONS: Endoscopic submucosal dissection when using the insulated-tip knife is feasible and efficacious for selected patients with mucosal early gastric cancer larger than 3 cm.