大腸T1癌治療後の長期予後 : 多施設コホート研究

内容の要旨 , 審査の要旨広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

SB Knife Jr: characteristics and tips on how to use

Widespread adoption of colorectal endoscopic submucosal dissection (ESD) in clinical practice is lagging despite the peer evidence that it permits en bloc resection of large lesions that can be curative and facilitate pathological staging, thereby improving management. Limited adoption of colorectal ESD is likely due to technical challenges and a steep learning curve. Most conventional ESD devices are used without fixing the target, making them difficult to maneuver and thus creating a potential risk of perforation. Comparatively, a scissor-type knife, such as the SB Knife Jr, enables grasping of the target tissue, facilitating controlled dissection of tissue being held between the blades. This potentially prevents unexpected muscular layer injury. Colorectal ESD with the SB Knife Jr does not require complex endoscopic maneuvering or advanced skills for safe ESD. Since the incision and dissection procedure using the SB Knife Jr is different from that of conventional ESD knives, familiarization with its features is vital. In this review, we focus on the use of the SB Knife Jr for colorectal ESD. The basic colorectal ESD procedure using the SB Knife Jr consists of grasping, pulling, and cutting. By repeating these steps, circumferential incision, submucosal dissection, and hemostasis can be performed with a single device. For incision and dissection, a circumferential mucosal incision is performed similar to “cutting paper”. Submucosal dissection is performed with the image of “connecting the dots at the appropriate dissection depth”. The SB Knife Jr is useful as a secondary device in challenging ESD procedures, and surgeons should master its use

Early Squamous Cell Carcinoma of the Anal Canal Resected by Endoscopic Submucosal Dissection

The standard treatment approach for squamous cell carcinoma (SCC) of the anal canal includes abdominoperineal resection and chemoradiotherapy. However, there are currently very few reports of early SCC of the anal canal resected by endoscopic submucosal dissection (ESD). We report 2 rare cases of SCC of the anal canal resected by ESD. In case 1, a 66-year-old woman underwent a colonoscopy due to blood in her stool, and an elevated lesion, 15 mm in size, was identified from the rectum to the dentate line of the anal canal on internal hemorrhoids. The lesion was diagnosed as an early SCC of the anal canal, and ESD was successfully performed. The histopathological diagnosis was SCC in situ. In case 2, a 71-year-old woman underwent a colonoscopy due to constipation, and an elevated lesion, 25 mm in size, was identified from the dentate line to the anal canal. The lesion was diagnosed as early-stage SCC of the anal canal, and ESD was successfully performed. The histopathological diagnosis was SCC in situ. No complications or recurrence after ESD occurred in either case

The Deployment of a Newly Developed Proximal Release-Type Colonic Stent Is Feasible for Malignant Colorectal Obstruction near the Anal Verge: A Single-Center Preliminary Study

Introduction: Colonic self-expandable metallic stents are widely used to treat malignant colorectal obstructions. Stent placement in lesions near the dentate line causes problems, including severe pain due to difficulty in positioning the stent accurately. Therefore, a proximal release-type stent was developed to overcome this issue, and this preliminary study aimed to investigate its efficacy and safety. Patients and Methods: This research enrolled eight patients with malignant colorectal obstructions up to 10 cm from the anal verge who required placement of the newly developed proximal release-type colonic stent. The primary outcome was the clinical success rate, and the secondary outcomes were the technical success and adverse events rates. Results: The technical and clinical success rates were 87.5% each, and the mean procedure time was 25.5 ± 22.0 min. The mean procedure time in the rectosigmoid colon was significantly longer than that in the rectum. Only one (12.5%) patient had stent migration, and neither anal pain nor tenesmus was observed. Discussion: The stent was highly effective in treating lesions near the anal verge, and it might contribute to the expansion of indications for colorectal stents for lesions near the dentate line. However, the indications for rectosigmoid colon lesions should be cautiously considered

Clinical impact of dual red imaging in colorectal endoscopic submucosal dissection: a pilot study

Background: Dual red imaging (DRI), a novel image-enhanced endoscopic technique, is expected to improve visibility of thin vessels, but no reports of the clinical use of DRI in colorectal endoscopic submucosal dissection (ESD) have been published. We aimed to compare the visibility of vessels, demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine, and fibrosis on DRI with that on white light imaging (WLI). We applied the principle of DRI to the image of the submucosal layer during colorectal ESD as a pilot study. Methods: A total of seven physicians compared 17 DRI images to the corresponding WLI images in colorectal ESD. The physicians compared the number of arteries identified on DRI with the actual number of arteries. The physicians rated the visibility of vessels, the demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine, and fibrosis. Inter-observer agreement was also examined using the kappa statistic. Results: Visibility of vessels and the demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine improved with the use of DRI compared with that using WLI. DRI can discriminate between arteries and veins clearly through the color of the vessels. Conclusions: DRI improves the visibility of vessels, especially that of arteries, as they appear orange, and the demarcation line of the muscle layer. DRI may help to make colorectal ESD safer and faster

Short-term outcomes of endoscopic submucosal dissection for superficial cecal tumors: a comparison between extension and nonextension into the appendiceal orifice

Background: Few studies have investigated the use of endoscopic submucosal dissection (ESD) for cecal tumors extending into the appendiceal orifice. Herein, we assessed the feasibility and safety of ESD for cecal tumors extending into the appendiceal orifice. Methods: We retrospectively examined the outcomes of ESD for 78 patients with 78 cecal tumors (male/female ratio, 40/38; mean [standard deviation, SD] age, 67 [9] years; mean [SD] tumor size, 32 [15] mm), who underwent ESD at the Hiroshima University Hospital between October 2008 and March 2016. The indication for ESD in cecal tumors extending into the appendiceal orifice was recognition of the distal edge of the lesion in the appendix. They were classified into two groups: patients with cecal tumors extending (Group A: 29 patients, 29 tumors) and not extending (Group B: 49 patients, 49 tumors) into the appendiceal orifice. We compared the outcomes of ESD between both groups. Results: No significant differences in clinicopathological characteristics were observed between both groups. The rate of severe submucosal fibrosis in Group A (48%) was significantly higher than that in Group B (24%) ( p < 0.05). The mean (SD) procedure speed in Group A (14 [10] mm 2 /min) was significantly slower than that in Group B (23 [16] mm 2 /min) ( p < 0.01). The en bloc resection rates in Groups A and B were 90% and 96%, respectively. There were no significant differences in adverse events reported between both groups. Conclusions: ESD for cecal tumors with extension into the appendiceal orifice is effective and safe