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 reported to be an efficient therapy for perforation. Most cases with perforation are treated conservatively without urgent surgical intervention. However, the rate of postoperative hemorrhage in ESD is similar to that in EMR. Endoscopic therapy including endoscopic clipping is performed and most of the cases are treated conservatively without blood transfusion. In blood examination, some degree of inflammation is detected after ESD. For the standardization of ESD, it is most important to decrease the rate of perforation. Adopting a safe strategy for ESD and a suitable choice of knife are both important waysof preventing perforation. Moreover, appropriate training and increasing experience can improve the endoscopic technique and can decrease the rate of perforation. In this review, we describe safe procedures in ESD to prevent complications, the complications of ESD and their management.

Efficient hemostatic method for endoscopic submucosal dissection of colorectal tumors

AIM:To evaluate a new hemostatic method using hemostatic forceps to prevent perforation and perioperative hemorrhage during colonic endoscopic submucosal dissection(ESD).METHODS:We studied 250 cases,in which ESD for colorectal tumors was performed at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2010.We developed a new hemostatic method using hemostatic forceps in December 2008 for the efficient treatment of submucosal thick vessels.ESD was performed on 126 cases after adoption of the new method(the adopted group)and the new method was performed on 102 of these cases.ESD was performed on 124 cases before the adoption of the new method (the unadopted group).The details of the new method are as follows:firstly,a vessel was coagulated using the hemostatic forceps in the soft coagulation mode according to the standard procedure,and the coagulated vessel was removed using the forceps in the"endocut" mode without perioperative hemorrhage.Secondly,the partial surrounding submucosa was dissected using the forceps in the endocut mode.In the current study,we evaluated the efficacy of this method.RESULTS:Coagulated vessels were successfully removed using the hemostatic forceps in all 102 cases without severe perioperative hemorrhage.Moderate perioperative hemorrhage occurred in five cases(4.9%);however,it was stopped by immediately reuse of the hemostatic forceps.The partial surrounding submucosa was dissected using the forceps in all 102 cases.In the adopted group,the median operation time was 105 min.The proportion of endoscopic en bloc resection was 92.8%(P<0.01)compared to 80.6%in the unadopted group.The postoperative hemorrhage and perforation rates were 2.3%and 2.3%.The rate of perforation was significantly lower than that in the unadopted group (9.6%,P<0.01).We evaluated the ease of use of this method by allowing our three trainees to performed ESD on 46 cases,which were accomplished without any severe hemorrhage.CONCLUSION:The new method effectively treated submucosal thick vessels and shows promise for the prevention of perforation and perioperative hemorrhage in colonic ESD.

Importance of histological evaluation in endoscopic resection of early colorectal cancer

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

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

Recently,image-enhanced endoscopy(IEE) has been used to diagnose gastrointestinal tumors.This method is a change from conventional white-light(WL) endoscopy without dyeing solution,requiring only the push of a button.In IEE,there are many advantages in diagnosis of neoplastic tumors,evaluation of invasion depth for cancerous lesions,and detection of neoplastic lesions.In narrow band imaging(NBI) systems(Olympus Medical Co.,Tokyo,Japan),optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used.Mucosal surface blood vessels are seen most clearly at 415 nm,which is the wavelength that corresponds to the hemoglobin absorption band,while vessels in the deep layer of the mucosa can be detected at 540 nm.Thus,NBI also can detect pit-like structures named surface pattern.The flexible spectral imaging color enhancement(FICE) system(Fujifilm Medical Co.,Tokyo,Japan) is also an IEE but different to NBI.FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images.FICE can enhance vascular and surface patterns.The autofluorescence imaging(AFI) video endoscope system(Olympus Medical Co.,Tokyo,Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions.AFI light comprises a blue light for emitting and a green light for hemoglobin absorption.The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment.

Gastric carcinoma originating from the heterotopic submucosal gastric gland treated by laparoscopy and endoscopy cooperative surgery

Gastric carcinoma is derived from epithelial cells in the gastric mucosa. We reported an extremely rare case of submucosal gastric carcinoma originating from the heterotopic submucosal gastric gland(HSG) that was safely diagnosed by laparoscopy and endoscopy cooperative surgery(LECS). A 66-year-old man underwent gastrointestinal endoscopy, which detected a submucosal tumor(SMT) of 1.5 cm in diameter on the lesser-anterior wall of the upper gastric body. The tumor could not be diagnosed histologically, even by endoscopic ultrasound-guided fine-needle aspiration biopsy. Local resection by LECS was performed to confirm a diagnosis. Pathologically, the tumor was an intra-submucosal well differentiated adenocarcinoma invading 5000 μm intothe submucosal layer. The resected tumor had negative lateral and vertical margins. Based on the Japanese treatment guidelines, additional laparoscopic proximal gastrectomy was curatively performed. LECS is a less invasive and safer approach for the diagnosis of SMT, even in submucosal gastric carcinoma originating from the HSG.

Rebamipide promotes healing of colonic ulceration through enhanced epithelial restitution

AIM:To investigate the efficacy of rebamipide in a rat model of colitis and restitution of intestinal epithelial cells in vitro.METHODS:Acute colitis was induced with trinitrobenzene sulfonic acid(TNBS)in male Wistar rats.Rats received intrarectal rebamipide treatment daily starting on day 7 and were sacrificed on day 14 after TNBS administration.The distal colon was removed to evaluate the various parameters of inflammation.Moreover,wound healing assays were used to determine the enhanced restitution of rat intestinal epithelial(RIE)cells treated with rebamipide.RESULTS:Intracolonic administration of rebamipide accelerated TNBSinduced ulcer healing.Increases in the wet weight of the colon after TNBS administration were significantly inhibited by rebamipide.The wound assay revealed that rebamipide enhanced the migration of RIE cells through phosphorylation of extracellular signalregulated kinase(ERK)and activation of Rho kinase.CONCLUSION:Rebamipide enema healed intestinal injury by enhancing restitution of RIE cells,via ERK activation.Rebamipide might be a novel therapeutic approach for inflammatory bowel disease.