• Clinical Endoscopy
• /
• v.55 no.1
• /
• pp.67-76
• /
• 2022

Background/Aims: Helicobacter pylori (H. pylori) seroconversion may occur during screening for gastric cancer. Our study aimed to assess the number of seroconverted subjects with H. pylori and their results in follow-up tests. Methods: Data were consecutively collected on subjects who were H. pylori-seronegative and presented for gastric cancer screening. Subjects who were followed up using the same serology test and pepsinogen (PG) assays on the day of endoscopy were included in the study. Results: During the follow-up of 57.7±21.4 months, 61 (15.0%) of 407 seronegative subjects showed seroconversion. H. pylori infection was detected in six (9.8%) of 61 seroconverted subjects. A diffuse red fundal appearance, with a significant increase in the Kyoto classification scores for gastritis, was observed in the infected subjects (p<0.001). Compared to the false-seropositive subjects, infected subjects showed higher serology titers (p<0.001) and PG II levels (p<0.001) and lower PG I/II ratios (p=0.002), in the follow-up tests. Conclusions: Seroconversion occurred in 3.3% of seronegative subjects per year; however, only 9.8% had H. pylori infection. The majority (90.2%) of the seroconverted subjects showed false seropositivity without significant changes in the follow-up test results. The diffuse red fundal appearance could be an indicator of H. pylori infection.

• Clinical Endoscopy
• /
• v.55 no.6
• /
• pp.703-725
• /
• 2022

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for the management of advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: (1) adenoma ≥10 mm in size; (2) 3 to 5 (or more) adenomas; (3) tubulovillous or villous adenoma; (4) adenoma containing high-grade dysplasia; (5) traditional serrated adenoma; (6) sessile serrated lesion (SSL) containing any grade of dysplasia; (7) serrated polyp of at least 10 mm in size; and (8) 3 to 5 (or more) SSLs. More studies are needed to fully comprehend the patients most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.8
• /
• pp.3591-3592
• /
• 2015

Endoscopy has been increasingly used in clinical practice and as a standardized examination procedure for gastrointestinal diseases. However, only a few studies on endoscopic screening for evaluating mortality reduction from gastric cancer have been carried out. Even if a high detection rate is obtained in clinical practice, such a rate cannot be directly accepted as evidence providing the effectiveness of cancer screening. Endoscopic screening for gastric cancer is not an exception of possibility to detect overdiagnosis. If detection rate is used for the evaluation of the effectiveness of cancer screening, the possibility of overestimating the effectiveness of cancer screening cannot be ruled out. To avoid the effect of overdiagnosis and confirm the effectiveness of endoscopic screening, mortality reduction from gastric cancer must be carefully evaluated by conducting reliable studies. The burden of gastric cancer remains real and this cannot be ignored in Eastern Asian countries. To determine the best available method for gastric cancer screening, evaluation of its effectiveness is a must. Endoscopic screening for gastric cancer has shown promising results, and thus deserves further comprehensive evaluation to reliably confirm its effectiveness and how its optimal use can be strategically promoted.

• Clinical Endoscopy
• /
• v.51 no.6
• /
• pp.596-599
• /
• 2018

An 89-year-old man was referred to our hospital for treatment of hepatolithiasis causing recurrent cholangitis. He had undergone a prior Whipple procedure. Computed tomography demonstrated left-sided hepatolithiasis. First, we conducted peroral direct cholangioscopy (PDCS) using an ultraslim endoscope. Although PDCS was successfully conducted, it was unsuccessful in removing all the stones. The stones located in the B2 segment were difficult to remove because the endoscope could not be inserted deeply into this segment due to the small size of the intrahepatic bile duct. Next, we substituted the endoscope with an upper gastrointestinal endoscope. After positioning the endoscope, the SpyGlass digital system (SPY-DS) was successfully inserted deep into the B2 segment. Upon visualizing the residual stones, we conducted SPY-DS-guided electrohydraulic lithotripsy. The stones were disintegrated and completely removed. In cases of PDCS failure, a treatment strategy using the SPY-DS can be considered for patients with hepatolithiasis after a Whipple procedure.

• Current Optics and Photonics
• /
• v.7 no.4
• /
• pp.398-407
• /
• 2023

We explored a method to evaluate imaging performance for the optimal assembly of an endoscopic miniature lens and a sensor constituting an imaging module at the distal end of gastrointestinal endoscopy. For the assembly of the imaging module, the image sensor was precisely located at the focal plane when collimated light passed through the endoscopic lens. As another method, the distance between the lens and sensor was adjusted to obtain the highest focus index from images measured the star chart of the International Organization for Standardization (ISO) standard at various positions. We analyzed the slanted-edge modulation transfer function (MTF), corresponding depth of field, and number of line pairs for MTF 50% and 20% at each working distance within the range of 5-100 mm for imaging modules assembled in different ways. Assembly conditions of the imaging module with better MTF performance were defined for each working distance range of 5-30 mm and 30-100 mm, respectively. In addition to the MTF performance, the focus index of each assembled module was also compared. In summary, we examined the performance of imaging modules assembled with different methods within the suggested working distance and tried to establish the optimal assembly protocol.

• Clinical Endoscopy
• /
• v.55 no.5
• /
• pp.615-625
• /
• 2022

Background/Aims: Mucosal incision-assisted biopsy (MIAB) for tissue acquisition (TA) from subepithelial lesions (SELs) is emerging as an alternative to endoscopic ultrasound (EUS)-guided TA. Only a limited number of studies compared the diagnostic utility of MIAB and EUS for upper gastrointestinal (GI) SELs; therefore, we conducted this systematic review and meta-analysis. Methods: A comprehensive literature search from January 2020 to January 2022 was performed to compare the diagnostic accuracy and safety of MIAB and EUS-guided TA for upper GI SELs. Results: Seven studies were included in this meta-analysis. The pooled technical success rate (risk ratio [RR], 0.96; 95% confidence interval [CI], 0.89-1.04) and procedural time (mean difference=-4.53 seconds; 95% CI, -22.38 to 13.31] were comparable between both the groups. The overall chance of obtaining a positive diagnostic yield was lower with EUS than with MIAB for all lesions (RR, 0.83; 95% CI, 0.71-0.98) but comparable when using a fine-needle biopsy needle (RR, 0.93; 95% CI, 0.83-1.04). The positive diagnostic yield of MIAB was higher for lesions <20 mm (RR, 0.75; 95% CI, 0.63-0.89). Six studies reported no adverse events. Conclusions: MIAB can be considered an effective alternative to EUS-guided TA for upper GI SELs without an increased risk of adverse events.

• Clinical Endoscopy
• /
• v.55 no.3
• /
• pp.408-416
• /
• 2022

Background/Aims: Endoscopic band ligation (EBL) is used to treat colonic diverticular bleeding (CDB). An endoscopic variceal ligation device for esophageal varices is used as a conventional EBL device (C-EBL). A new EBL device (N-EBL) was developed by Sumitomo Bakelite Co. in August 2018. We aimed to evaluate the clinical outcomes of N-EBL compared with those of C-EBL. Methods: Seventy-nine patients who underwent EBL for CDB at St. Luke's International Hospital, Japan, between 2017 and 2020 were included in this retrospective study. Patients were divided into the C-EBL and N-EBL groups. Their clinical outcomes, including achieving initial hemostasis, early rebleeding, procedure time, and EBL-associated adverse events, were evaluated. Results: Of the 79 patients, 36 (45.6%) were in the C-EBL group and 43 (54.4%) were in the N-EBL group. The rate of achieving initial hemostasis was 100% in the C-EBL group and 93.0% in the N-EBL group. No significant difference was noted in the early rebleeding rate between the groups (p=0.24). The N-EBL group achieved a shorter median EBL procedure time than the C-EBL group (14.2 minutes vs. 18.2 minutes, p=0.02). No adverse events were observed in either group. Conclusions: The N-EBL device is safe and useful and may reduce EBL procedure time.

• Journal of Biomedical Engineering Research
• /
• v.31 no.5
• /
• pp.335-343
• /
• 2010

This article presents a review of technologies for an endoscope. The classification according to the clinical applications and the imaging modalities are summarized. The major parts are focused on describing the gastrointestinal endoscope's structures and mechanisms. The details of the image enhanced endoscopic techniques, such as NBI (narrow band imaging), OCT (optical coherence tomography), and EUS (endoscopic ultrasound), are also explained. Finally, the trend of NOTES (natural orifice transluminal endoscopic surgery) which is new fusion technology in the field of endoscopic diagnosis and surgery is introduced.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.21 no.3
• /
• pp.209-213
• /
• 2018

Most solitary gastrointestinal (GI) polyps in children are either inflammatory or hamartomatous. Solitary hyperplastic polyp, sentinel polyp and solitary adenomatous polyp have been occasionally diagnosed in adults, but very rarely reported in Korean children. We recently came across a case with adenomatous polyp in the colon, a case with hyperplastic polyp beneath the gastroesophageal junction, a case with hyperplastic polyp in the prepyloric area, and a case with sentinel polyp in the distal esophagus, which are unusual pathologic types in children. These mucosal lesions were diagnosed incidentally during elective endoscopic examinations for GI symptoms. Most polyps do not cause significant symptoms, so the diagnosis might be delayed, especially in children, in whom GI endoscopy is not commonly performed for screening purpose as in the adults.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.22 no.2
• /
• pp.189-192
• /
• 2019

Gastric duplication cysts (GDCs) are rare congenital anomalies. Presentation of GDCs varies from an asymptomatic abdominal mass to fulminant or massive gastrointestinal (GI) bleeding. Herein, we describe a case of a GDC in a 10-month-old infant presenting with unexplained massive GI hemorrhage and hematemesis. An abdominal ultrasound was negative, while computerized tomography was, initially, inaccessible. Through a series of repeated esophagogastroduodenoscopies, we documented penetration of the GDC into the gastric cavity that was later confirmed by computerized tomography. The patient was treated successfully with surgical resection.