Maki Ayaki

Current Innovations in Endoscopic Therapy for the Management of Colorectal Cancer: From Endoscopic Submucosal Dissection to Endoscopic Full-Thickness Resection

Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment for colorectal cancer. However, due to technical difficulties and an increased rate of complications, ESD is not widely used in the colorectum. In some cases, endoscopic treatment alone is insufficient for disease control, and laparoscopic surgery is required. The combination of laparoscopic surgery and endoscopic resection represents a new frontier in cancer treatment. Recent developments in advanced polypectomy and minimally invasive surgical techniques will enable surgeons and endoscopists to challenge current practice in colorectal cancer treatment. Endoscopic full-thickness resection (EFTR) of the colon offers the potential to decrease the postoperative morbidity and mortality associated with segmental colectomy while enhancing the diagnostic yield compared to current endoscopic techniques. However, closure is necessary after EFTR and natural transluminal endoscopic surgery (NOTES). Innovative methods and new devices for EFTR and suturing are being developed and may potentially change traditional paradigms to achieve minimally invasive surgery for colorectal cancer. The present paper aims to discuss the complementary role of ESD and the future development of EFTR. We focus on the possibility of achieving EFTR using the ESD method and closing devices.

Reduction effect of bacterial counts by preoperative saline lavage of the stomach in performing laparoscopic and endoscopic cooperative surgery

AIM To investigate the effects of gastric lavage with 2000 mL of saline in laparoscopic and endoscopic cooperative surgery. METHODS Twenty two patients who were diagnosed with a gastric gastrointestinal stromal tumor were enrolled. In former term, irrigations of the stomach were conducted whenever it was necessary, not systematically (Non systemic lavage group). In latter term, the stomach was thoroughly cleaned with 2000 mL of saline using an endoscope with a water jet, and Duodenal balloon occlusion was conducted to prevent refluxed bile and pancreatic juice (Systemic lavage+balloon occlusion group). The gastric wall was sprayed with 20 mL of distilled water, and 20 mL of gastric juice was collected in a sterile tube and submitted for culture. 20 mL of ascites was also collected from the laparoscopic ports and submitted for culture. We compared WBC, CRP, BT between two groups, and verify the reduction effect of bacterial counts in Systemic lavage+balloon occlusion group. RESULTS WBC count before, 1 d after, and 3 d after laparoscopic and endoscopic cooperative surgery (LECS) were 5060 (95%CI: 4250-9640), 12140 (6050-14110), and 6910 (5320-12520) in Non systemic lavage group, 4400 (3660-7620), 8910 (6480-10980), and 5950 (4840-7860) in Systemic lavage+balloon occlusion group. Significant differences between two groups at the day after LECS (P = 0.029) and the 3 d after LECS (P = 0.042). CRP levels in Non systemic lavage group and in Systemic lavage+balloon occlusion group were significantly different at the day after LECS (P = 0.005) and the 3 d after LECS (P = 0.028). BTs (°C) in Non systemic lavage group and in Systemic lavage+balloon occlusion group were also significantly different at the day after LECS (P = 0.004) and the 3 d after LECS (P = 0.006). In a logarithmic comparison, bacterial load before gastric lavage, after lavage, and ascites culture were 6.08 (95%CI: 4.04-6.97), 0.48 (0-0.85), and 0.21 (0-0.56). The bacterial counts before and after gastric lavage were significantly suppressed (P = 0.007), but no significant difference between gastric juice culture after lavage and ascites (P = 0.154). CONCLUSION Pre-LECS lavage with 2000 mL of saline exhibited a bacteria-reducing effect equivalent to disinfectants and obtained favorable results in terms of clinical symptoms and data.

Submucosal tunneling techniques: current perspectives

Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

Analysis of the amount of tissue sample necessary for mitotic count and Ki-67 index in gastrointestinal stromal tumor sampling

There are no established opinions concerning whether the amount of tissue affects the accuracy of histological analyses in gastrointestinal stromal tumors (GISTs). The aim of the present study was to investigate the appropriate amount of tissue sample needed for mitotic count based on the risk classification of GISTs and the Ki-67 index using the following three methods: endoscopic ultrasound-guided fine-needle aspiration (FNA), a novel sampling method called tunneling bloc biopsy (TBB), and biopsy forceps followed by TBB (Bf). Forty-three samples (12 FNA, 17 TBB and 14 Bf) diagnosed as GISTs by immunohistological analysis were utilized. The major and minor axes and overlay area of one piece of specimen (OPS) from the three sampling methods were measured using digital imaging software and were analyzed comparatively regarding the acquisition of histological data. The mean major and minor axes (mm) and overlay areas (mm2) were in the order of TBB > Bf > FNA. The evaluable rates by mitotic count and Ki-67 were, respectively, 75% (9/12) and 83.3% (10/12) for FNA samples, 100% (17/17) and 100% (17/17) for TBB samples, and 100% (14/14) and 100% (14/14) for Bf samples (P>0.05). Three FNA samples were judged unevaluable due to too small specimens in overall diagnosis including mitotic count and Ki-67, calculating the cut-off value for the overlay area of OPS as 0.17 mm2. Comparing the concordance rates between the pre- and post-operative samples, TBB samples was significantly better than FNA (P<0.05). Conclusively, while the amounts of tissues obtained by TBB and Bf are unnecessary for the histological assessment of mitotic count and Ki-67 index, developments of the FNA method are needed to minimize sample error. Considering the technical aspects, as well as the size of the specimens, could help to guide therapeutic planning and improve diagnostic yield for GI subepithelial tumors.

Management of a large mucosal defect after duodenal endoscopic resection

Duodenal endoscopic resection is the most difficult type of endoscopic treatment in the gastrointestinal tract (GI) and is technically challenging because of anatomical specificities. In addition to these technical difficulties, this procedure is associated with a significantly higher rate of complication than endoscopic treatment in other parts of the GI tract. Postoperative delayed perforation and bleeding are hazardous complications, and emergency surgical intervention is sometimes required. Therefore, it is urgently necessary to establish a management protocol for preventing serious complications. For instance, the prophylactic closure of large mucosal defects after endoscopic resection may reduce the risk of hazardous complications. However, the size of mucosal defects after endoscopic submucosal dissection (ESD) is relatively large compared with the size after endoscopic mucosal resection, making it impossible to achieve complete closure using only conventional clips. The over-the-scope clip and polyglycolic acid sheets with fibrin gel make it possible to close large mucosal defects after duodenal ESD. In addition to the combination of laparoscopic surgery and endoscopic resection, endoscopic full-thickness resection holds therapeutic potential for difficult duodenal lesions and may overcome the disadvantages of endoscopic resection in the near future. This review aims to summarize the complications and closure techniques of large mucosal defects and to highlight some directions for management after duodenal endoscopic treatment.

Suitable closure for post-duodenal endoscopic resection taking medical costs into consideration

AIM To compare closure methods, closure times and medical costs between two groups of patients who had post-endoscopic resection (ER) artificial ulcer floor closures. METHODS Nineteen patients with duodenal adenoma, early duodenal cancer, and subepithelial tumors that received ER between September 2009 and September 2014 at Kagawa University Hospital and Ehime Rosai Hospital, an affiliated hospital of Kagawa University, were included in the study. We retrospectively compared two groups of patients who received post-ER artificial ulcer floor closure: the conventional clip group vs the over-the-scope clip (OTSC) group. Delayed bleeding, procedure time of closure, delayed perforation, total number of conventional clips and OTSCs and medical costs were analyzed. RESULTS Although we observed delayed bleeding in three patients in the conventional clip group, we observed no delayed bleeding in the OTSC group (P = 0.049). We did not observe perforation in either group. The mean procedure times for ulcer closure were 33.26 ± 12.57 min and 9.71 ± 2.92 min, respectively (P = 0.0001). The resection diameters were 18.8 ± 1.30 mm and 22.9 ± 1.21 mm for the conventional clip group and the OTSC group, respectively, with significant difference (P = 0.039). As for medical costs, the costs of all conventional clips were USD

Novel method for the management of stenosis after gastric endoscopic submucosal dissection: Mucosal incision with steroid injection contralateral to the severely contracted scar

1257 and the costs of OTSCs were

Two rare gastric hamartomatous inverted polyp cases suggest the pathogenesis of growth.

7850 (P = 0.005). If the post-ER ulcer is under 20 mm in diameter, a conventional clip closure may be more suitable with regard to the prevention of delayed perforation and to medical costs. CONCLUSION If the post-ER ulcer is over 20 mm, the OTSC closure should be selected with regard to safety and reliable closure even if there are high medical costs.

Current Status of Exposed Endoscopic Full-Thickness Resection and Further Development of Non-Exposed Endoscopic Full-Thickness Resection.

The aim of the present report was to investigate the efficacy of local steroid injection and oral administration contralateral to a severe contracted scar of large endoscopic submucosal dissection (ESD) for gastric cancer. Among 254 cases that underwent gastric ESD, seven patients underwent resection of more than three‐quarters of the circumference of the stomach. Two patients were excluded because they did not meet curative resection criteria of Japan Gastroenterological Endoscopy Society. Therefore, in five patients, circumferentiality, symptom appearance period, and weight loss period were examined. Effect of a contralateral normal mucosa incision for releasing the stenosis followed by local injection and oral steroids were also examined. Abdominal bloating, vomiting, and loss of appetite appeared 42 days on average after gastric ESD, whereas weight loss >5 kg was observed an average of 52.6 days after gastric ESD. Average contralateral mucosal incision length was 51 mm, whereas the average mucosal incision width was 31 mm. All patients underwent a mucosal incision and were given a local injection of 100 mg triamcinolone acetonide. Two patients received an additional 20 mg oral steroid. In cases combined with oral steroid, there was no re‐stenosis after the mucosal incision, but two to three balloon dilatations were necessary in three cases in which oral steroids were not given. This method is considered useful for stenosis after large ESD for gastric cancer.

Evaluation of gastric submucosal tumors using endoscopically visualized features with submucosal endoscopy

Gastric hamartomatous inverted polyps (GHIP) are difficult to diagnose accurately because of inversion into the submucosal layer. GHIP are diagnosed using the pathological characteristics of the tumor, including the fibroblast cells, smooth muscle, nerve components, glandular hyperplasia, and cystic gland dilatation. Although Peutz-Jeghers syndrome, juvenile polyposis, and Cowden disease are hereditary, it is rare to encounter 2 cases of monostotic and asymptomatic gastric hamartomas. The pathogeneses of hamartomatous inverted polyps and inverted hyperplastic polyps remain controversial because of the paucity of reported cases. There are 3 hypotheses regarding the pathogenesis of complete gastric inverted polyps. Based on our experience with 2 successive, rare GHIP cases, we affirm the hypothesis that after a hamartomatous change occurs in the submucosal layer, some of these components are exposed to the gastric mucosa and, consequently, form a hypertrophic lesion. In Case 1, our hypothesis explains why a tiny hypertrophic change was first detected on the top of the submucosal tumor using a detailed narrow band imaging-magnified endoscopy. There was no confirmation that the milky white mucous and calcification structures were exuding directly from the biopsy site like Case 1, and in Case 2 the presence of this mucous was indirectly confirmed during an endoscopic submucosal dissection (ESD). Regarding the pathogenesis of GHIP, a submucosal hamartomatous change may occur prior to the growth of hypertrophic portions. An en bloc resection using ESD is recommended for treatment.