Clinical experience of using a novel self‐help inflatable balloon to prevent esophageal stricture after circumferential endoscopic submucosal dissection

Although endoscopic submucosal dissection (ESD) is gradually becoming a first‐line treatment for superficial esophageal neoplasms (SEN), strictures occur in almost 100% of cases after circumferential ESD. A standard method to prevent stricture has not been established. Thus, we propose a novel self‐help inflatable balloon to prevent stricture. The new balloon was used by the patients themselves at home (4–5 times a day, duration of each procedure was approximately 15–20 min), and was removed when the defects were almost healed. From January 2018 to September 2018, eight patients who received circumferential ESD for SEN and underwent a novel self‐help inflatable balloon to prevent stricture were enrolled. Median size of the mucosal defects was 76.3 mm (range: 50–90 mm). Median time for removing the self‐help inflatable balloon was 94.6 days (range, 71–119 days). Only one (12.5%) patient experienced stricture, and three endoscopic balloon dilation sessions were carried out for this patient. All patients tolerated the balloon well, and none experienced perforation or delayed bleeding. The self‐help inflatable balloon seems to show a high preventive effect against stricture in patients whose mucosal defect was no longer than 100 mm in length after esophageal circumferential ESD. This method is economic, feasible, and safe.     

Chemically assisted endoscopic mechanical submucosal dissection by using mesna

BACKGROUND: A class of thiol compounds, mesna (sodium-2-mercaptoethanesulfonate), has been used to facilitate tissue dissection in surgical fields. OBJECTIVES: To evaluate the technical feasibility and efficacy of chemically assisted endoscopic mechanical submucosal dissection (CAEMSD) by using mesna. DESIGN: An in vivo controlled blind trial by using porcine models. SETTINGS: Nonsurvival study in an animal laboratory. INTERVENTIONS: Six pigs were studied. Mucosal targets of about 2 cm (estimated) for treatment were created with a circle of cauterized spots along the greater curvature of the gastric body and the antrum. A mesna solution or the control hydroxypropyl methylcellulose solution was submucosally injected. The target mucosa was mechanically isolated with balloon dissection and removed by circumferential incision with a hook-knife inserted into the submucosal space. Necropsy and mucosal specimens from both groups were examined by histology. RESULTS: En bloc resection of the target was achieved in all 8 attempts of the mesna group and in 7 of 8 attempts of the control group. Use of mesna significantly reduced tissue resistance to the initial balloon-catheter insertion into the submucosa and the technical difficulty of subsequent submucosal balloon dissection by using a subjective grading system (P < .05). There was no difference in histology between both groups. CONCLUSIONS: CAEMSD is a unique methodology to facilitate mucosal resection.     

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.     

Gastrointestinal investigation of iron deficiency anaemia detected by pre-blood donation screening

Abstract

Objectives. Endoscopic submucosal dissection (ESD) is a technically difficult, hazardous, and time-consuming treatment option for superficial neoplasms of the esophagus. The aim of this pilot study was to determine the effectiveness and safety of percutaneous transgastric traction (PTT)-assisted ESD, a method that overcomes the drawbacks of conventional ESD, in a porcine model. Methods. Six domestic pigs (25–30 kg) were used in the study. In each animal, two 5-cm-long esophageal areas were assigned randomly for resection by conventional ESD or PTT-assisted ESD. The PTT method was designed to offer esophageal mucosal traction directed toward the stomach. The wire was introduced into the stomach through a percutaneous transgastric cannula and was fixed on the resected esophageal mucosa. Results. Submucosal dissection in the traction group required only half the time of that in the non-traction group (mean dissection time 596.0 vs. 1127.3 s, respectively; p = 0.01). At necropsy, no differences in the incidence of perforation or bleeding were found between two groups. Conclusions. The PTT method can enhance the speed of submucosal dissection for esophageal ESD to completely remove large areas of resected mucosa.     

Optimal injection solution for endoscopic submucosal dissection: A randomized controlled trial of Western solutions in a porcine model

Background and Aim

When carrying out endoscopic submucosal dissection (ESD), procedural safety increases with greater tissue elevation and efficiency increases with longer‐lasting submucosal cushion. Fluids specifically developed for ESD in Asia are not commercially available in the West, leaving endoscopists to use a variety of injectable fluids off‐label. To determine the optimal fluid available in the West, we compared commonly used fluids for Western ESD.

Methods

All phases were carried out in an ex vivo porcine stomach model. Phase 1 compared tissue elevation and duration of submucosal cushions produced by various standard volumes of various injectable solutions used for ESD. The two best‐performing solutions used off‐label were tested head‐to‐head in ESD in Phase 2. Phase 3 compared the best solution from Phase 2 to Eleview^®, currently the only submucosal injection fluid approved in the USA. In Phases 2 and 3, five ESD were carried out with each solution. The solutions were randomized and the endoscopist blinded to the solution.

Results

The best‐performing solutions in Phase 1 were 0.4% hyaluronic acid, 6% hydroxyethyl starch (HES), and Eleview^®. Phase 2 compared 6% HES and hydroxypropyl methylcellulose (HPMC), showing that ESD with 6% HES was easier (P = 0.007), faster (P = 0.041) and required less injection volume (P = 0.003). In Phase 3, resection speed, ease of ESD and total volume per area resected were comparable between 6% HES and Eleview^®.

Conclusions

Of the submucosal injection fluids currently available in the West, Eleview^® and 6% HES are the best‐performing solutions for ESD in a porcine model.     

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.     

Case series of endoscopic balloon dilation to treat a stricture caused by circumferential resection of the gastric antrum by endoscopic submucosal dissection

BACKGROUND: Endoscopic submucosal dissection (ESD) plays an important role in the management of gastric neoplasms. There are few reports regarding stricture development caused by ESD of gastric neoplasms. OBJECTIVE: The present study aimed to determine the incidence of gastric stricture formation after ESD of gastric neoplasms and to report on the outcome and management of this complication: endoscopic intervention (ie, balloon dilation) versus surgery; the outcome of balloon dilation (success or failure/perforation). DESIGN: A case series from a retrospective review of gastric ESDs performed at Saga Medical School over a defined period of time. SETTING: Double-center territory, referral hospital. PATIENTS: An evaluation was performed in 532 patients with gastric mucosal tumors treated by ESD. A stricture was reported in 5 patients. All the 5 cases were located in the antrum. ESD that was performed in the cardia or the proximal stomach did not induce a stricture. RESULTS: Of the 5 cases of symptomatic gastric outlet obstruction, 1 patient required surgical intervention because of a near total gastric outlet obstruction not amenable to endoscopic intervention. The 4 patients underwent step-serial through-the-scope balloon dilations; in 2 patients, the procedure was successful, but in the other 2 patients, the procedure was complicated by a gastric perforation (50% incidence of perforation). LIMITATION: A retrospective study. CONCLUSIONS: Circumferential or subcircumferential resection by ESD in the antrum caused a stricture. Balloon dilation of the ESD gastric outlet obstruction might be a choice, but it is a risky treatment.     

Development of novel treatment with a bioabsorbable esophageal patch for benign esophageal stricture

Using a large animal model, we examined whether circumferential stricture after esophageal endoscopic submucosal dissection (ESD) can be treated by grafting a bioabsorbable esophageal patch. Circumferential ESD was performed on the thoracic esophagus in pigs (n = 6) to create a stricture, for which one of the following interventions was performed: (1) the stricture site was longitudinally incised, and an artificial esophageal wall (AEW) was grafted after placing a bioabsorbable stent (AEW patch group, n = 3); (2) endoscopic balloon dilation (EBD) was performed every other week after stricture development (EBD group, n = 3). In both groups, esophageal fluoroscopy was performed 8 weeks after the interventions, and the esophagus was excised for histological examination of the patched site. In the AEW patch group, esophageal fluoroscopy revealed favorable passage through the patched site. Histologically, the mucosal epithelium and lamina propria had regenerated as in the normal area. In the EBD group, the circumferential stricture site showed marked thickening, and there were hypertrophic scars associated with epithelial defects on the luminal surface. Histologically, defects of the mucosal epithelium and full‐thickness proliferation of connective tissue were observed. AEW patch grafting was suggested to be a potentially novel treatment strategy for post‐ESD esophageal circumferential stricture.     

离体猪胃黏膜下隆起性病变模型的建立及其在内镜黏膜下剥离术中的应用研究

目的 探讨离体猪胃黏膜下隆起性病变模型的制作方法及其在内镜黏膜下剥离术（ESD）中的应用。方法 应用硅橡胶印模材料和直径1 cm、2 cm、3 cm钢球制成半球形阴模,将生牛肉糜放进阴模,两个阴模对合固定,置入100℃水中煮沸20 min后制成球形肿物模型。选取离体猪胃6只,将球形肿物模型经猪胃浆膜层切口置入黏膜下层,每只离体猪胃的胃底、胃体、胃窦部各置入1枚,直径分别为1 cm、2 cm、3 cm。应用胃镜及内镜超声对模型进行观察,并对黏膜下隆起性病变行ESD。结果 6只猪胃共置入肿物模型18枚,其中17枚成功置入,1例失败。置入的17枚肿物模型在内镜下均表现为明显向腔内凸起的占位改变,表面黏膜与周边黏膜对比无明显改变。内镜超声下表现为位于黏膜下层的混合回声占位。对肿物模型进行ESD,与实际ESD操作过程基本一致,未出现肿物模型脱出、破碎等影响操作的情况。结论 本方法制作的胃黏膜下隆起性病变模型可较好复制疾病状态,为胃黏膜下隆起性病变内镜治疗方法研究及内镜医师培训提供了一个较为合适的模型。     

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.     

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.     

内镜黏膜下剥离术治疗上消化道病灶的初步评价

目的 探讨内镜下黏膜剥离术(ESD)处理上消化道病灶的疗效和安全性.方法 以胃镜检查发现的上消化道黏膜病灶及黏膜下病灶作为入选对象,通过超声内镜和(或)活检病理检查明确病灶大小、位置、范围、性质,应用钩刀、IT刀、氩气刀及高频电凝电切术进行ESD操作,步骤包括:(1)胃镜及黏膜染色确定病灶,针刀或者氩气刀标记病灶;(2)黏膜下注射含靛胭脂及肾上腺素生理盐水抬高病变;(3)预切开病变周围黏膜一圈;(4)自病变黏膜下层完整剥离病灶.术后应用抑酸、黏膜保护剂治疗,术后第1、2、6个月内镜随访,评价溃疡是否愈合以及病灶有无残留与复发.结果 2006年8月至2008年1月,共153例患者进入观察研究.黏膜病变85例(溃疡型病灶2例,隆起型病灶48例,糜烂型病灶35例),病灶直径0.4～5.0 cm,平均2.0 cm;手术时间15～210 min.平均55min.所有病例均切除病灶,其中1例迟发性出血行内镜下紧急止血,7例穿孔均保守治疗愈合.随访期溃疡创面均愈合,其中4例复发,3例再次ESD完整切除病灶,1例手术切除.黏膜下肿瘤68例,52例术前行超声内镜检查,其余病例经术后病理证实.病灶直径0.4～4.0 cm,平均1.2 cm;手术时间10～182 min,平均41 min;68例完整剥离黏膜下肿瘤,1例改行尼龙绳结扎治疗.1 1例穿孔均保守治疗,1例术后出血未控制行手术治疗.结论 ESD作为一种微创治疗方法,能实现较大病变的一次性大块剥离,剥离的病变能提供完整的病理诊断资料,病变局部的复发率低,并发症少,为上消化道黏膜层病灶尤其是早期肿瘤以及黏膜下肿瘤的治疗开辟了新的途径.     

Novel method to prevent gastric antral strictures after endoscopic submucosal dissection: Using triamcinolone

Endoscopic submucosal dissection (ESD) of large gastric lesions often leads to severe gastric strictures, especially in cases of large ESD in the antrum of the stomach. It has recently been reported that balloon dilation, mucosal incision, and local steroid injections can successfully treat gastric strictures. However, there are some complications with existing methods and decreasing the quality of life. We have developed a novel method to prevent severe gastric strictures that does not involve balloon dilation, mucosal incision, or steroid injections after circumferential ESD. Our original method involves the submucosal injection of a mixed solution composed of triamcinolone acetonide and a general solution of glycerol, hyaluronic acid, and a small amount of indigo carmine and epinephrine during the ESD procedure; this mixture is called a mixed solution of triamcinolone (MST). According to standard ESD procedures, several milliliters of MST are injected into the submucosal layer for the purpose of elevating the submucosa during ESD resulting in prevention of severe strictures. Our method using MST take several advantages such as MST method suppress inflammation in ulcer from initial phase, prevention of stricture without obstructive symptoms, and does not require several ballooning. Therefore, MST method is safe and gentle, shorten the hospitalization duration. Here, we described two cases in which we prevented severe strictures of the gastric antrum after completing a circumferential ESD using MST without any complications.     

Predictive factors for esophageal stenosis after endoscopic submucosal dissection for superficial esophageal cancer

Endoscopic submucosal dissection (ESD) has been utilized as an alternative treatment to endoscopic mucosal resection for superficial esophageal cancer. We aimed to evaluate the complications associated with esophageal ESD and elucidate predictive factors for post‐ESD stenosis. The study enrolled a total of 42 lesions of superficial esophageal cancer in 33 consecutive patients who underwent ESD in our department. We retrospectively reviewed ESD‐associated complications and comparatively analyzed regional and technical factors between cases with and without post‐ESD stenosis. The regional factors included location, endoscopic appearance, longitudinal and circumferential tumor sizes, depth of invasion, and lymphatic and vessel invasion. The technical factors included longitudinal and circumferential sizes of mucosal defects, muscle disclosure and cleavage, perforation, and en bloc resection. Esophageal stenosis was defined when a standard endoscope (9.8 mm in diameter) failed to pass through the stenosis. The results showed no cases of delayed bleeding, three cases of insidious perforation (7.1%), two cases of endoscopically confirmed perforation followed by mediastinitis (4.8%), and seven cases of esophageal stenosis (16.7%). Monovalent analysis indicated that the longitudinal and circumferential sizes of the tumor and mucosal defect were significant predictive factors for post‐ESD stenosis (P < 0.005). Receiver operating characteristic analysis showed the highest sensitivity and specificity for a circumferential mucosal defect size of more than 71% (100 and 97.1%, respectively), followed by a circumferential tumor size of more than 59% (85.7 and 97.1%, respectively). It is of note that the success rate of en bloc resection was 95.2%, and balloon dilatation was effective for clinical symptoms in all seven patients with post‐ESD stenosis. In conclusion, the most frequent complication with ESD was esophageal stenosis, for which the sizes of the tumor and mucosal defect were significant predictive factors. Although ESD enables large en bloc resection of esophageal cancer, practically, in cases with a lesion more than half of the circumference, great care must be taken because of the high risk of post‐ESD stenosis.     

Endoscopic submucosal dissection in dogs in a World Gastroenterology Organisation training center

AIM: To evaluate if canine models are appropriate for teaching endoscopy fellows the techniques of endoscopic submucosal dissection (ESD). METHODS: ESD was performed in 10 canine models under general anesthesia, on artificial lesions of the esophagus or stomach marked with coagulation points. After ESD, each canine model was euthanized and surgical resection of the esophagus or stomach was carried out according to “The Principles of Humane Experimental Technique, Russel and Burch“. The ESD specimens were fi...     

CARBON DIOXIDE SUBMUCOSAL INJECTION CUSHION: AN INNOVATIVE TECHNIQUE IN ENDOSCOPIC SUBMUCOSAL DISSECTION

Aim: Endoscopic submucosal dissection (ESD) can successfully resect large lesions en bloc, but it requires a satisfactory submucosal (sm) injection agent for proper safety and efficacy. The aim of the present study was to evaluate the effectiveness of carbon dioxide (CO₂) as an ESD sm injection agent. Methods: In vitro study using porcine stomachs compared CO₂ with normal saline (NS) and sodium hyaluronic acid (SHA) solution, both of which are currently used to provide long‐lasting sm elevation during ESD. Histopathological examination assessed differences between CO₂ and NS sm cushions. ESD were then carried out in vivo in the stomach and rectum of a live pig using CO₂ sm injection. Results: CO₂ sm elevation was significantly longer lasting than either NS or SHA (P < 0.001). Histopathology revealed no mucosal layer tissue damage, and dissection of honeycomb‐like fibrous connective tissue in the CO₂ sm cushion. Creating and maintaining a CO₂ sm cushion of sufficient elevation combined with partial physical dissection of the sm layer was achieved, followed by complete endoscopic dissection of the sm layer with all ESD, resulting in successful en‐bloc resections having a mean specimen size of 24.3 mm within 15 min. Conclusion: Safety and efficacy of CO₂ as a satisfactory sm injection agent during ESD was successfully demonstrated in these preliminary studies, warranting further investigation of this innovative technique.     

Endoscopic submucosal dissection for cancers of the remnant stomach after distal gastrectomy

BACKGROUND: Endoscopic submucosal dissection (ESD) of early gastric cancer is less invasive than surgical resection, and if technically feasible, it may result in less long-term morbidity than does incisional surgery. However, ESD is technically difficult in patients who have had a previous distal gastrectomy. OBJECTIVE: Our purpose was to retrospectively assess the results of ESD of early gastric cancer in the remnant stomach. DESIGN: Case series. SETTING AND PATIENTS: A total of 31 lesions in 30 patients with early remnant gastric cancer were treated with ESD at Okayama University Hospital, Tsuyama Central Hospital, Hiroshima City Hospital, Kagawa Prefectural Central Hospital, and Mitoyo General Hospital from March 2001 to January 2007. INTERVENTION: ESD. MAIN OUTCOME MEASUREMENTS: En bloc resection rate, complete resection rate, operation time, and complications. RESULTS: En bloc resection and complete resection were achieved in 30 (97%) and in 23 (74%) lesions, respectively. The median operation time required for ESD in the remnant stomach was 113 minutes (range 45-450 minutes). Perforation occurred in 4 (13%). The incidence of delayed bleeding requiring blood transfusion was 0%. LIMITATION: Short duration of follow-up. CONCLUSIONS: ESD is feasible in the remnant stomach but has a relatively high complication rate and should only be performed by experienced endoscopists.     

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.     

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.     

Thin endoscope-assisted endoscopic submucosal dissection for large colorectal tumors (with videos)

BACKGROUND: Endoscopic submucosal dissection (ESD) enables direct submucosal dissection so even large early stage GI tumors can be resected en bloc. Colorectal ESD is technically more difficult, however, and there is an increased risk of complications such as perforation and bleeding compared with gastric ESD. As a result, further refinements are required in this procedure. OBJECTIVE: Our purpose was to evaluate thin endoscope-assisted (TEA) ESD, a new traction system for improving submucosal cutting line visualization. DESIGN: Case series. SETTING: Okayama University Hospital. MAIN OUTCOME MEASUREMENTS: Efficacy and safety of the TEA-ESD procedure. RESULTS: Three cases of large, flat, elevated colorectal tumors (laterally spreading tumors) in the rectum and rectosigmoid colon were safely and successfully removed en bloc without complications. Total procedure times were 3 hours, 40 minutes, and 30 minutes with resected specimens measuring 70 x 68 mm, 38 x 35 mm, and 30 x 20 mm, respectively. LIMITATIONS: TEA-ESD was performed in only the rectum and rectosigmoid colon. CONCLUSIONS: This limited case series demonstrated that large laterally spreading tumors in the rectum and rectosigmoid colon could be safely resected en bloc with TEA-ESD.