Endoscopic carbon dioxide insufflation tolerance test on the anal sphincter for anorectal hypofunction: a pilot and feasibility study.

Background: Anorectal function deteriorates with age. The diagnostic performance of the endoscopic pressure study integrated system (EPSIS), an endoscopic carbon dioxide (CO2) insufflation stress test of the lower esophageal sphincter has been previously evaluated as a diagnostic tool for gastroesophageal reflux disease. We aimed to evaluate the applicability of EPSIS in improving anorectal function. We hypothesized that EPSIS can be applied to the diagnosis of lower gastrointestinal tract disorders. Methods: This was a pilot, single-center, retrospective study using prospectively collected data between December 2021 and March 2022. It was designed to evaluate the differences in EPSIS rectal pressure measurements between older (≥80 years) and younger (<80 years) patients. At the end of the screening colonoscopy, the colonoscope was fixed in a retroflex position. When bowel movement was observed, CO2 was insufflated to the point where gas leakage occurred through the anus. The measured maximum pressure was defined as EPSIS-rectal pressure max (EPSIS-RP max) and compared between the groups. Results: Overall, 30 patients were included and examined. The median ages of the <80 and ≥80 years' groups were 53 (range: 27-79) and 82 (range: 80-94) years, respectively, with corresponding median measured EPSIS-RP max of 18.7 (range: 8.5-30.2) and 9.8 (range: 5.4-22.3) mmHg (P<0.001). Conclusions: Measurement of maximum rectal pressure illustrates the age-related decline in physiological anorectal function. Future studies should consider a loading test using EPSIS to quantify the decline in anorectal function and use it as a routine tool for screening and adjunctive diagnosis of anorectal hypofunction.

Determination of esophageal squamous cell carcinoma and gastric adenocarcinoma on raw tissue using Raman spectroscopy.

BACKGROUND: Cancer detection is a global research focus, and novel, rapid, and label-free techniques are being developed for routine clinical practice. This has led to the development of new tools and techniques from the bench side to routine clinical practice. In this study, we present a method that uses Raman spectroscopy (RS) to detect cancer in unstained formalin-fixed, resected specimens of the esophagus and stomach. Our method can record a clear Raman-scattered light spectrum in these specimens, confirming that the Raman-scattered light spectrum changes because of the histological differences in the mucosal tissue. AIM: To evaluate the use of Raman-scattered light spectrum for detecting endoscop-ically resected specimens of esophageal squamous cell carcinoma (SCC) and gastric adenocarcinoma (AC). METHODS: We created a Raman device that is suitable for observing living tissues, and attempted to acquire Raman-scattered light spectra in endoscopically resected specimens of six esophageal tissues and 12 gastric tissues. We evaluated formalin-fixed tissues using this technique and captured shifts at multiple locations based on feasibility, ranging from six to 19 locations 200 microns apart in the vertical and horizontal directions. Furthermore, a correlation between the obtained Raman scattered light spectra and histopathological diagnosis was performed. RESULTS: We successfully obtained Raman scattered light spectra from all six esophageal and 12 gastric specimens. After data capture, the tissue specimens were sent for histopathological analysis for further processing because RS is a label-free methodology that does not cause tissue destruction or alterations. Based on data analysis of molecular-level substrates, we established cut-off values for the diagnosis of esophageal SCC and gastric AC. By analyzing specific Raman shifts, we developed an algorithm to identify the range of esophageal SCC and gastric AC with an accuracy close to that of histopathological diagnoses. CONCLUSION: Our technique provides qualitative information for real-time morphological diagnosis. However, further in vivo evaluations require an excitation light source with low human toxicity and large amounts of data for validation.

A novel endoscopic purse-string suture technique, "loop 9", for gastrointestinal defect closure: a pilot study.

BACKGROUND : This study aimed to assess the feasibility and efficacy of the novel loop 9 method of gastrointestinal (GI) defect closure. METHODS : 20 patients underwent a GI procedure that required defect closure. Loop 9 can be delivered through a single instrument channel (3.2 mm) and released at the defect site. After it has been anchored by two clips positioned on opposite sides of the defect edge, the loop 9 is tightened by pulling the end of the suture intraluminally using biopsy forceps. Additional clips are placed to achieve complete closure. The primary outcome was complete closure rate. The secondary outcomes were closure time, sustained closure rate, and adverse events. RESULTS : Complete closure was achieved in 100 % of cases. The mean size of the mucosal defects was 17.5 mm (range 10-55 mm). The median closure time was 14 minutes. The sustained closure rate was 90 %. No adverse events were noted. CONCLUSIONS : The loop 9 technique is feasible and effective in achieving complete and sustained closure of therapeutic endoscopy-related GI defects.

Unified magnifying endoscopic classification for esophageal, gastric and colonic lesions: a feasibility pilot study.

Background and study aims Image-enhanced magnifying endoscopy allows optimization of the detection and diagnosis of lesions found in the gastrointestinal tract. Current organ-specific classifications are well-accepted by specialized endoscopists but may pose confusion for general gastroenterologists. To address this, our group proposed the Unified Magnifying Endoscopic Classification (UMEC) which can be applied either in esophagus, stomach, or colon. The aim of this study was to evaluate the diagnostic performance and clinical applicability of UMEC. Patients and methods A single-center, feasibility pilot study was conducted. Two endoscopists with experience in magnifying narrow band imaging (NBI), blinded to white-light and non-magnifying NBI findings as well as histopathological diagnosis, independently reviewed and diagnosed all images based on UMEC. In brief, UMEC is divided into three categories: non-neoplasia, intramucosal neoplasia, and deep submucosal invasive cancer. The diagnostic performance of UMEC was assessed while using the gold standard histopathology as a reference. Results A total of 303 gastrointestinal lesions (88 esophageal squamous lesions, 90 gastric lesions, 125 colonic lesions) were assessed. The overall accuracy for both endoscopists in the diagnosis of esophageal squamous cell cancer, gastric cancer, and colorectal cancer were 84.7 %, 89.5 %, and 83.2 %, respectively. The interobserver agreement for each organ, Kappa statistics of 0.51, 0.73, and 0.63, was good. Conclusions UMEC appears to be a simple and practically acceptable classification, particularly to general gastroenterologists, due to its good diagnostic accuracy, and deserves further evaluation in future studies.

Highly accurate colorectal cancer prediction model based on Raman spectroscopy using patient serum.

BACKGROUND: Colorectal cancer (CRC) is an important disease worldwide, accounting for the second highest number of cancer-related deaths and the third highest number of new cancer cases. The blood test is a simple and minimally invasive diagnostic test. However, there is currently no blood test that can accurately diagnose CRC. AIM: To develop a comprehensive, spontaneous, minimally invasive, label-free, blood-based CRC screening technique based on Raman spectroscopy. METHODS: We used Raman spectra recorded using 184 serum samples obtained from patients undergoing colonoscopies. Patients with malignant tumor histories as well as those with cancers in organs other than the large intestine were excluded. Consequently, the specific diseases of 184 patients were CRC (12), rectal neuroendocrine tumor (2), colorectal adenoma (68), colorectal hyperplastic polyp (18), and others (84). We used the 1064-nm wavelength laser for excitation. The power of the laser was set to 200 mW. RESULTS: Use of the recorded Raman spectra as training data allowed the construction of a boosted tree CRC prediction model based on machine learning. Therefore, the generalized R 2 values for CRC, adenomas, hyperplastic polyps, and neuroendocrine tumors were 0.9982, 0.9630, 0.9962, and 0.9986, respectively. CONCLUSION: For machine learning using Raman spectral data, a highly accurate CRC prediction model with a high R 2 value was constructed. We are currently planning studies to demonstrate the accuracy of this model with a large amount of additional data.

Raman spectroscopic evaluation of human serum using metal plate and 785- and 1064-nm excitation lasers.

In this study, we utilized a stainless steel (SUS304) plate for measuring the Raman scattering spectra of body fluid samples. Using this stainless steel plate, we recorded the Raman scattering spectra of 99.5% ethanol and human serum samples by performing irradiation with 785- and 1064-nm lasers. Raman scattering spectra with intensities equal to or greater than those reported previously were obtained. In addition, the Raman scattering spectra acquired using the 1064-nm laser were less influenced by autofluorescence than those obtained via use of the shorter-wavelength laser. Moreover, the shapes of the spectra did not show any dependence on integration time, and denaturation of the samples was minimal. Our method, based on 1064-nm laser and the stainless steel plate, provides performance equal to or better than the methods reported thus far for the measurement of Raman scattering spectra from liquid samples. This method can be employed to rapidly evaluate the components of serum in liquid form without using surface-enhanced Raman scattering.

Raman spectroscopy for the diagnosis of unlabeled and unstained histopathological tissue specimens.

AIM: To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS: We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis. RESULTS: A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm-1 and 782 cm-1, are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm-1/620 cm-1, 782 cm-1/756 cm-1, 782 cm-1/1250 cm-1, and 782 ​​cm-1/1263 cm-1 in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue. CONCLUSION: The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens.

Risk factors for bleeding after endoscopic submucosal dissection of colorectal neoplasms.

AIM: To investigate the risk factors for delayed bleeding following endoscopic submucosal dissection (ESD) treatment for colorectal neoplasms. METHODS: We retrospectively reviewed the medical records of 317 consecutive patients with 325 lesions who underwent ESD for superficial colorectal neoplasms at our hospital from January 2009 to June 2013. Delayed post-ESD bleeding was defined as bleeding that resulted in overt hematochezia 6 h to 30 d after ESD and the observation of bleeding spots as confirmed by repeat colonoscopy or a required blood transfusion. We analyzed the relationship between risk factors for delayed bleeding following ESD and the following factors using univariate and multivariate analyses: age, gender, presence of comorbidities, use of antithrombotic drugs, use of intravenous heparin, resected specimen size, lesion size, lesion location, lesion morphology, lesion histology, the device used, procedure time, and the presence of significant bleeding during ESD. RESULTS: Delayed post-ESD bleeding was found in 14 lesions from 14 patients (4.3% of all specimens, 4.4% patients). Patients with episodes of delayed post-ESD bleeding had a mean hemoglobin decrease of 2.35 g/dL. All episodes were treated successfully using endoscopic hemostatic clips. Emergency surgery was not required in any of the cases. Blood transfusion was needed in 1 patient (0.3%). Univariate analysis revealed that lesions located in the cecum (P = 0.012) and the presence of significant bleeding during ESD (P = 0.024) were significantly associated with delayed post-ESD bleeding. The risk of delayed bleeding was higher for larger lesion sizes, but this trend was not statistically significant. Multivariate analysis revealed that lesions located in the cecum (OR = 7.26, 95%CI: 1.99-26.55, P = 0.003) and the presence of significant bleeding during ESD (OR = 16.41, 95%CI: 2.60-103.68, P = 0.003) were independent risk factors for delayed post-ESD bleeding. CONCLUSION: Location in the cecum and significant bleeding during ESD predispose patients to delayed post-procedural bleeding. Therefore, careful and additional management is recommended for these patients.

Diagnosis of laterally spreading tumors (LST) in the rectum and selection of treatment: characteristics of each of the subclassifications of LST in the rectum.

BACKGROUND: In recent years, endoscopic submucosal dissection (ESD) has often been used for the treatment of laterally spreading tumors (LST) of the rectum. The present study was carried out with the aim of clarifying the characteristics of each of the subtypes of LST in the rectum that are often treated by ESD. PATIENTS AND METHODS: This study involved 141 rectal LST that were initially treated at our hospital between March 2005 and December 2010 and whose endoscopic images and histopathological specimens could be re-examined. The LST were divided into LST-G-H (homogeneous type), LST-G-MIX (nodular mixed type), LST-NG-F (flat type) and LST-NG-PD (pseudo-depressed type) type lesions, and tumor diameter and depth of invasion of each of these tumor types were investigated. RESULTS: Regarding the depth of invasion, the proportion of submucosa-massive (SM-m) lesions was high in the LST-NG-PDtumors, even among tumors measuring <20 mm in diameter; both the rate of cancer and proportion of SM-m lesions were significantly higher in the LST-NG-PD tumors than in the LST-NG-F tumors (P < 0.05). In both LST-NG-MIX and LST-NG-PD tumors, the proportion of SM-m lesions was significantly higher in the lower rectum than in the upper rectum (P < 0.05). CONCLUSION: For LST of the rectum (particularly of the lower rectum), it is necessary to carefully select the treatment considering LST subclass and tumor diameter from the standpoint of the presence of malignancy, quality of life, and prognosis of patients.

Usefulness of sodium hyaluronate solution in colorectal endoscopic mucosal resection.

BACKGROUND: In endoscopic mucosal resection (EMR), it is essential to inject submucosal fluid to prevent complications and ensure safe and complete en bloc resection of tumors. Sodium hyaluronate (SH) solution, which is effective in forming and maintaining a mucosal lift and is innocuous to mucosal tissue, is considered a useful injection solution for endoscopic submucosal dissection, a procedure associated with a high risk of perforation. This study was undertaken to assess the usefulness of this solution in EMR. METHODS: Ninety-four patients with colorectal tumors of ≤20 mm in diameter were enrolled for this study and randomized to a SH solution group (0.2% two-fold diluted MucoUp) or to a normal saline group (control). Ease of EMR was primarily assessed based on ease of submucosal injection, ease of snaring and injection time. RESULTS: SH solution was superior to normal saline for ease of submucosal injection (57 ± 0.7 vs 50 ± 0.7; P < 0.05), and it showed better results for ease of snaring with less variability (63 ± 0.8 vs 51 ± 1.0; P < 0.05). The mean injection time was similar between the two groups (3.0 ± 9.0 s and 3.0 ± 2.7 s, respectively). Post-procedural hemorrhage occurred in 7% patients (3/46) injected with SH solution and in 6% of patients (3/48) in the control group; there was no significant difference between the groups. CONCLUSIONS: Use of two-fold diluted MucoUp facilitated colorectal EMR.

Treatment strategy for rectal carcinoids: a clinicopathological analysis of 229 cases at a single cancer institution.

BACKGROUND AND AIM: A treatment strategy for tumors with only venous invasion and characteristics of small rectal carcinoids with metastasis have not been clearly documented. The present study aims to determine the risk factors for lymph node metastasis and to elucidate characteristics of small tumors with metastasis. METHODS: We investigated a total of 229 patients with rectal carcinoids. The relationship between each clinicopathological variable and the presence of lymph node metastasis was evaluated. RESULTS: Tumor size (larger than 10 mm), presence of central depression, depth of tumor invasion, lymphatic invasion, and venous invasion were significantly associated with the incidence of lymph node metastasis (P < 0.001). Multivariate analysis revealed that tumor size (odds ratio: 63.3, P < 0.001) and venous invasion (odds ratio: 40.9, P < 0.001) were independently predictive of lymph node metastasis. In 204 patients with small (no larger than 10 mm) tumors, 10 patients had lymph node metastasis. All 10 tumors had low proliferation values indicated by mitosis and Ki-67 index. Multivariate analysis for the 204 patients revealed that only venous invasion was independently associated with metastasis (odds ratio: 40.1, P < 0.001). Five-year disease free survival rates of the total patients with metastasis and without metastasis were 81.1% and 95.5%, respectively (P < 0.001, log-rank test). CONCLUSIONS: Venous invasion as well as tumor size and lymphatic invasion indicates high malignant potential to metastasize to lymph node and would provide useful information in considering the addition of radical surgery. Postoperative pathological examinations of specimens obtained by local resection are very important to avoid underestimation.

Comparison of the diagnostic utility of the ultrathin endoscope and the conventional endoscope in early gastric cancer screening.

Currently, transnasal esophagogastroduodenoscopy using an ultrathin endoscope is being widely carried out as a screening test for early gastric cancer. We compared the diagnostic utility of ultrathin esophagogastroduodenoscopy with that of conventional esophagogastroduodenoscopy in detecting 42 lesions of early gastric cancer that had a diameter of

Re-epithelialization of squamous epithelium for a radiation-induced rectal ulcer while giving an ecabet sodium enema.

The present patient developed a severe rectal ulcer more than 1 month after having received external beam radiation therapy for prostate cancer. Surveillance endoscopy every 3 months demonstrated healing of this rectal ulcer using a novel therapy. He was given enemas with ecabet sodium, which provides physical protection and promotes healing by increasing prostaglandin E(2), and this process induced squamous metaplasia that halted the progression of the ulcer of radiation proctitis as a late-phase reaction. Intrapapillary capillary loops were visualized with magnified narrow band imaging at the healing ulcer site as seen via the esophagus and, moreover, demonstrated histologically.

Significance of (18)F-2-deoxy-2-fluoro-glucose accumulation in the stomach on positron emission tomography.

OBJECTIVE: To explain the accumulation of (18)F-2-deoxy-2-fluoro-glucose ((18)FDG) on positron emission tomography (PET) in the stomach and differences in its pattern, we focus on the accumulation pattern in association with endoscopic findings of the gastric mucosa and Helicobacter pylori (Hp) infection. METHODS: Of 599 cases undergoing (18)FDG-PET examinations, we retrospectively analyzed the pattern of (18)FDG accumulation in the stomach, findings of upper gastrointestinal endoscopy, and Hp infection. The pattern of (18)FDG accumulation was classified into three groups: localized accumulation only in the fornix (Group A, 32 patients), diffuse accumulation throughout the entire stomach (Group B, 49 patients), and no accumulation (Group C, 191 patients). RESULTS: Regarding the relation between Hp infection and (18)FDG accumulation, Hp infection was positive in 56.3% of Group A, 73.5% of Group B, and 24.1% of Group C, with significant differences (p < 0.001). Regarding the relation between (18)FDG accumulation and gastric mucosal inflammation, when Groups A and B were compared with Group C, nearly half of the cases in the former groups had papular redness with a significantly higher frequency of redness and erosion. Three cases found to have malignant tumor were limited to the former groups. One MALT lymphoma case was also found in the same group. Accumulation of (18)FDG largely corresponded to mucosal inflammation including superficial gastritis and erosive gastritis, and therefore the main cause of non-specific (18)FDG accumulation was considered to be inflammatory mucosa (mainly redness). The accumulation pattern was not associated with atrophic changes of the gastric mucosa or with Hp infection, but with mucosal inflammatory changes, including redness and erosion localized to the fornix. CONCLUSIONS: Accumulation of (18)FDG in the stomach suggests a high probability of the presence of inflammatory change in the gastric mucosa forming a background for the development of cancer or malignant lymphoma, and thus requires further endoscopic examinations.

[Therapeutic strategy for hemorrhagic radiation proctitis--the optimum condition of argon plasma coagulation (APC)].

AIM: This study was performed to clarify the optimum condition of argon plasma coagulation (APC) to treat hemorrhagic radiation proctitis. SUBJECTS: Among 25 patients with hemorrhagic radiation proctitis treated in the Cancer Institute Hospital between December 2000 and May 2004, 18 were followed-up for more than 6 months. The clinical courses of these 18 patients were analyzed retrospectively. METHODS: Proctoscopic findings of the hemorrhagic lesions were categorized as type-A (localized dilated veins, n = 6) , type-B (diffuse dilated veins, n = 6), and type-C (dilated veins associated with ulcers orerosions, n = 6). APC was applied for 5-10 seconds with the power of 40 W and the argon flow of 1.0 l/min (high power APC), or for 1-2 seconds with the power of 40 W and the argon flow of 0.6 l/min (low power APC). RESULTS: Type-A and B patients were successfully treated with either low or high power APC without any serious complications. But some type-C patients treated with high power APC showed serious complications such as proctovaginal fistula or prolonged ulceration. No recurrence patients were 89% (16/18) during the mean follow up period of 18 +/- 9.9 months. CONCLUSION: APC therapy for hemorrhagic radiation-proctitis was useful, but the pathologic healing process and consequence were different by rectal mucosal weakness. It is necessary for the therapeutic strategy to be put up and down according to proctoscopic findings. As for the optimum condision APC short cauterization by low power setting was more recommended.

A comparison of depth of tissue injury caused by different modes of electrosurgical current in a pig colon model.

BACKGROUND: This study compared tissue injury produced by 3 types of electrosurgical current (pure cut, coagulation, blend) and two different procedures (snare and "hot biopsy"). METHODS: Each type of electrosurgical current was passed through the colon of a live pig by means of a snare or "hot biopsy" forceps, and the depth of tissue injury was determined histologically. The high-frequency electrosurgical current was provided by a single electrosurgical generator. The peak power for each type of current was determined with an oscilloscope. RESULTS: The depth of tissue injury caused by coagulation current was significantly greater compared with blended current (p=0.0157). The depth of injury with coagulation current also was greater than with pure cut current, (p=0.0461 in a single statistical test; significance removed by Bonferroni-Dunn correction). With the hot biopsy forceps, the depth of tissue injury was deeper compared with that produced with a snare, regardless of the diameter of the snare loop. Peak power at a setting of 30 W was 1154 W for coagulation, 90.2 W for pure cut, and 227.8 W for blend current. CONCLUSIONS: When a high-frequency electrosurgical current device is used, use of a cutting current in the blend mode is recommended instead of coagulation current because this waveform is suitable for incision and provides effective hemostasis. Skillful technique is required for safe use of a hot biopsy forceps, because there is a significant potential for deeper tissue injury with this device.