Objective Interpretation of the Rapid Urease Test for Helicobacter pylori Infection Using Colorimetry

Pih Gyu Young,Noh Jin Hee,Ahn Ji Yong,Han Gill Sang,Jung Hyun Suk,Jung Hwoon-Yong,Kim Jung Mogg 대한의학회 2022 Journal of Korean medical science Vol.37 No.29

Background: The rapid urease test (RUT) is a major diagnostic tool for detecting Helicobacter pylori infection. This study aimed to establish an objective method for measuring the color changes in the RUT kit to improve the test’s diagnostic accuracy. Methods: A UV-visible spectrophotometer was selected as the colorimeter; experiments were conducted in three stages to objectively identify the color changes in the RUT kit. Results: First, the urea broth solution showed an identifiable color change from yellow to red as the pH increased by 0.2. The largest transmittance difference detected using the UV-visible spectrophotometer was observed at a 590-nm wavelength. Second, the commercialized RUT kit also showed a gradual color change according to the pH change detected using the UV-visible spectrophotometer. Third, 13 cases of negative RUT results with a biopsy specimen and 16 of positive RUT results were collected. The transmittance detected using the UV-visible spectrophotometer showed a clear division between the positive and negative RUT groups; the largest difference was observed at a 559-nm wavelength. The lowest transmittance in the negative RUT group was 64, while the highest in the positive RUT group was 56, at the 559-nm wavelength. The UV-visible spectrophotometry reading showed a consistency of 92.7% compared with that of manual reading. Conclusion: A transmittance of 60 at a 559-nm wavelength detected using UV-visible spectrophotometer can be used as a cutoff value for interpreting RUT results; this will help develop an automatic RUT kit reader with a high accuracy.

Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy in Gastrointestinal Subepithelial Tumors

Gyu Young Pih,Do Hoon Kim 대한소화기내시경학회 2019 Clinical Endoscopy Vol.52 No.4

The incidence of asymptomatic and incidentally found upper gastrointestinal subepithelial tumors (SETs) is increasing with theimplementation of national cancer screening and the development of high-resolution endoscopy in Korea. However, endoscopy alonecannot be used to determine whether SETs are benign or malignant. Endoscopic ultrasound (EUS) is used to further characterize theselesions through the examination of their layered structure, internal echogenicity, size, and relationship to the extramural structure. Theseprovide additional information on whether the lesion is benign or malignant. Nevertheless, the sensitivity and specificity of EUS alonein predicting malignancy is unsatisfactory. Recent guidelines have recommended deciding the timing of EUS-fine needle aspiration andbiopsy (EUS-FNA/B) for SETs based on tumor size, malignant features on endoscopy, and high-risk features on EUS. The diagnosticaccuracy of EUS-FNA/B is reportedly influenced by factors including needle size, number of needle passes, use of suction, use of a styletin the needle assembly, fanning technique, availability of an on-site cytopathologist, and experience of the endosonographer. Therefore,according to the characteristics of the SETs, various subsequent methods and techniques should be appropriately employed to improvethe diagnostic yield of EUS-FNA/B.

표재성 식도암 내시경 절제 후 발생하는 이시성 암

Gyu Young Pih,Do Hoon Kim 대한상부위장관ㆍ헬리코박터학회 2020 Korean Journal of Helicobacter Upper Gastrointesti Vol.20 No.4

Esophageal cancer has a relatively high prevalence of local recurrence, which is associated with a poor prognosis. Superficial esophageal cancer has shown a metachronous recurrence rate of 2.6~35.8% with the cumulative overall 3-year and 5-year metachronous cancer incidence being 9.9~15.5% and 20.6~24.5%, respectively. In addition to recurrences in the remnant esophagus, second metachronous primary tumors have been reported to arise in 4.0~37.4% of esophageal cancer survivors. The second primary cancers arising after a diagnosis of esophageal cancer are most commonly detected in the head and neck area, followed by the lungs and stomach. The field cancerization theory explains the high prevalence of head and neck cancer among esophageal cancer patients. The reported risk factors for metachronous esophageal recurrences include scattered-type Lugol staining, circumferential endoscopic resection of the primary lesion, heavy alcohol use, smoking, inactive aldehyde dehydrogenase-2 genes, alcohol dehydrogenase-1B genes, and young age at diagnosis of the primary cancer. The risk factors for metachronous second primary tumors include heavy alcohol use, smoking, and a previous history of radiation therapy. Consequently, periodic follow-up endoscopy using narrow-band imaging is essential for the screening of metachronous esophageal cancers and second primary tumors after endoscopic resection for superficial esophageal cancer.

Clinical Outcomes of Percutaneous Endoscopic Gastrostomy in the Surgical Intensive Care Unit

Gyu Young Pih,나희경,Suk-Kyung Hong,Ji Yong Ahn,Jeong Hoon Lee,Kee Wook Jung,Do Hoon Kim,Kee Don Choi,Ho June Song,Gin Hyug Lee,Hwoon-Yong Jung 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.6

Background/Aims: Percutaneous endoscopic gastrostomy (PEG) is usually performed on patients with chronic underlying diseasesin the general ward (GW). This study evaluated the clinical outcomes of PEG performed on patients in the surgical intensive careunit (SICU) compared with those of PEG performed in the GW. Methods: The medical records of 27 patients in the SICU and 263 in the GW, who underwent PEG between January 2013 and July2017, were retrospectively reviewed. Results: The median age of the 27 SICU patients was 66 years, and their median body mass index was 21.1 kg/m2. In the SICUgroup, the median baseline Sequential Organ Failure Assessment (SOFA) score was 4, and the median Acute Physiology and ChronicHealth Evaluation II (APACHE II) score was 16. The median interval between surgery and PEG in SICU patients was 30 days,with a PEG failure rate of 3.7%. Acute complications in SICU patients included bleeding (7.4%) and ileus (11.1%), while chroniccomplications included aspiration pneumonia (7.4%) and tube obstruction (3.7%). The rates of acute and chronic complications didnot differ significantly between the SICU and GW groups. The 30-day mortality rate was 14.8% in SICU patients and 5.3% in GWpatients (p=0.073). Conclusions: PEG is a safe and feasible method of enteral feeding for critically ill patients who require ICU care after surgery.

Is Ex Vivo Training before In Vivo Training Effective in Learning Gastric Endoscopic Submucosal Dissection?

Gyu Young Pih,Jung Su Lee,Ji Yong Ahn,Do Hoon Kim,Hee Kyong Na,Jeong Hoon Lee,Kee Wook Jung,Kee Don Choi,Ho June Song,Gin Hyug Lee,Hwoon-Yong Jung 대한상부위장관ㆍ헬리코박터학회 2021 Korean Journal of Helicobacter Upper Gastrointesti Vol.21 No.2

Background/Aims: The learning curve is essential in endoscopic submucosal dissection (ESD) training to improve outcomes and reduce the risk of procedure-related complications. We compared the outcomes of gastric ESD in live pigs performed by inexperienced endoscopists with or without ex vivo training. Materials and Methods: At the Olympus Medical Training and Education Center, nine endoscopists inexperienced in ESD were randomly divided into two groups (group A: ex vivo training followed by in vivo training; group B: in vivo training only), and they performed gastric ESDs. Results: A total of 18 ESDs were performed. The en bloc resection rate was 88.9% (16/18), and the complete resection rate was 94.4% (17/18). The median specimen size was 2.5 cm in group A and 2.1 cm in group B (P=0.227). There was no significant difference in the procedure time between the two groups, except for the marking time (0′58″ vs. 2′58″, P=0.027). However, group A took a shorter time in dissecting the same area than group B (109 vs. 246 sec/cm2, P=0.083). Complication rates were not significantly different between both groups. Conclusions: The procedure time during in vivo ESD training in pigs may be shortened by prior ex vivo training. However, the ex vivo model presented poor air inflation, unstable fixation, and excessive mucosal hardness for cutting. An advanced simulator or sufficient ex vivo training may be effective in training for the ESD procedure.

Single-Center 11 Years Experience of Percutaneous Endoscopic Gastrostomy with 410 Patients

( Gyu Young Pih ),( Heekyong Na ),( Kee Wook Jung ),( Do Hoon Kim ),( Jeong Hoon Lee ),( Ji Yong Ahn ),( Kee Don Choi ),( Ho June Song ),( Gin Hyug Lee ),( Hwoon-yong Jung ) 한국정맥경장영양학회 2017 한국정맥경장영양학회 학술대회집 Vol.2017 No.-

Backgroud and aim: Percutaneous endoscopic gastrostomy (PEG) is the most common enteral nutritional method for patients who are difficult in oral feeding and have normal gastrointestinal function. Although PEG is an uncomplicated and minimal invasive procedure, minor and major complications have been constantly reported. The aim of this study is by reviewing single center PEG cases to analyze major and minor complications and 30-day mortality after PEG. Patients and Methods: 410 Patients who received PEG insertion at the Asan medical center between January 2005 and December 2015 were eligible. The medical records were retrospectively reviewed and clinical characteristics were investigated. Results: The median age was 68.5 years (IQR 57-77) and median BMI was 19.6 kg/m2 (IQR 17.2-21.7). The median follow up period was 355 days (IQR 80-792). The indications of PEG insertion were stroke (22.0%), parkinsonism (14.9%), neuromuscular disease (12.9%), head and neck cancer (12%), dementia (6.1%), esophageal cancer (5.1%), hypoxic brain damage (4.1%) and other indications (22.9%). One hundred forty-three patients (34.9%) underwent PEG insertion with the pull technique while two hundreds sixty-three patients (64.1%) with the introducer technique. Incidence of acute and chronic complications except chronic tube obstruction showed no significant difference between the pull type and the introducer type. Thirty-five patients (8.5%) had developed major complications and ninety-seven patients (23.7%) had showed minor complications. The 30-day mortality rates were 4.9%. In multivariate analysis, comorbidity of chronic kidney disease (Odds ratio 7.08, 95% CI: 1.86-26.92 and p value=0.004), low platelet (Odds ratio 1.007, 95% CI: 1.013- 1.002 and p value=0.013) and high CRP level (Odds ratio 1.15, 95% CI: 1.06-1.26 and p value=0.002) were significant risk factors of 30-day mortality. Conclusion: With relatively long term data, PEG is a safe and feasible procedure. However, comorbidity of chronic kidney disease, low platelet count, and elevated CRP level can be predictors of 30-day mortality.

경피적내시경위조루술 후 발생한 위천공의 내시경적 봉합 1예

피규영 ( Gyu Young Pih ),나희경 ( Hee Kyong Na ) 대한내과학회 2018 대한내과학회지 Vol.93 No.3

경피적내시경위조루술은 비교적 안전하지만 침습적인 시술로 크고 작은 합병증들이 보고되었다. 위 천공은 주요 합병증 중 하나이며, 일반적으로 수술적 처치가 필요하다. 경피적내시경위조루술을 받는 대부분의 환자가 중증 만성 기저 질환을 가지고 있으며 전반적인 컨디션이 좋지 않기 때문에 수술을 시행하게 되면 수술 관련한 후속 합병증이 발생할 위험이 크다. 본 증례에서 진행된 뇌교종을 앓고 있는 75세 여자가 외부 병원에서 경장 영양을 위한 경피적내시경위조루술을 시행받았다. 시술로부터 4일 후 발열과 의식 혼돈을 보였으며 그로부터 3일 후 전신 긴장성 간대성 발작이 발생하여 본원 응급실로 전원되었다. 진단적 검사 결과 위루관의 탈구와 위벽 결함이 확인되었다. 이에 위루관을 제거하였고 위벽은 박리성 올가미, 금속 클립, 피브린 글루를 이용하여 내시경적 봉합을 하였다. 시술 3주 후 시행한 조영제 투시검사에서 누출이 없음을 확인하였고 합병증 없는 상태로 경장영양을 재시작하였다. Percutaneous endoscopic gastrostomy (PEG) is a relative safe but invasive procedure associated with both minor and major complications. Gastric perforation is one of the major complications, usually requiring surgical intervention. As most patients undergoing PEG have severe, chronic underlying diseases and are in a poor general condition, surgical intervention may substantially increase the risk of subsequent complications. A 75-year-old female suffering from an advanced glioblastoma underwent PEG to allow enteral nutrition in a local hospital. Four days later, she presented with fever and confusion. Three days after that, she presented with a generalized tonic-clonic seizure and was referred to the Asan Medical Center emergency room. Diagnostic work-up revealed PEG tube dislocation and a gastric wall defect. Therefore, the PEG tube was removed and endoscopic primary closure was performed using a detachable snare, hemoclips, and fibrin glue. Three weeks after closure, fluoroscopy revealed no leakage and the patient resumed enteral feeding without any complication. (Korean J Med 2018;93:291-295)

Main duct and mixed type intraductal papillary mucinous neoplasms without enhancing mural nodules: Duct diameter of less than 10 mm and segmental dilatation of main pancreatic duct are findings support surveillance rather than immediate surgery

Kim, Tae Hyeon,Song, Tae Jun,Lee, Seung Ok,Park, Chang Hwan,Moon, Jong Ho,Pih, Gyu Young,Oh, Dong Wook,Woo, Sang Myoung,Yang, Yun Jung,Kim, Myung Hwan Elsevier 2019 PANCREATOLOGY Vol.19 No.8

<P><B>Abstract</B></P> <P><B>Objective</B></P> <P>The guidelines for pancreatic intraductal papillary mucinous neoplasms (IPMNs) recommend surgical resection of all main-duct (MD) and mixed-type IPMNs in surgically fit patients. We conducted this study to identify the rates of high-grade dysplasia (HGD) and invasive carcinoma according to the morphological features of the main pancreatic duct (MPD) in patients with MD and mixed IPMN.</P> <P><B>Methods</B></P> <P>We performed a retrospective study of 259 patients with histologically proven MD and mixed-type IPMNs who underwent surgery at six academic institutions.</P> <P><B>Results</B></P> <P>The rate of HGD and invasive carcinoma was 11.1% (24/216) in patients without enhancing mural nodules (MNs) and 69.8% (30/43) in patients with MNs. Multivariate analysis showed that MPD diameter of ≥10 mm [odds ratio (OR), 2.5; 95% confidence interval (CI), 1.155–5.505; <I>P</I> = 0.02], diffuse MPD dilatation (OR, 3.2; 95% CI, 1.152–8.998; <I>P</I> = 0.02), and presence of enhancing MNs in MPD (OR, 9.6; 95% CI, 3.928–23.833, P < 0.0001) were significant predictors of HGD and invasive carcinoma. Of the 216 patients without enhancing MNs, 79 patients (36.6%) having both segmental MPD dilatation and MPD diameter of <10 mm showed significantly lower rates of HGD and invasive carcinoma (3/79, 3.8%) than patients having both diffuse MPD dilatation and MPD diameter ≥10 mm (9/36, 25%, <I>P</I> = 0.001).</P> <P><B>Conclusions</B></P> <P>MD and mixed-type IPMNs having segmental MPD dilatation with MPD dilation <10 mm and no enhancing MNs on imaging showed a significantly lower rate of HGD and invasive carcinoma, and watchful follow-up instead of immediate surgical resection might be possible in these patients.</P>

Impact of Coronavirus Disease 2019 on Gastric Cancer Diagnosis and Stage: A Single-Institute Study in South Korea

정민규,Moonki Hong,Mingee Choi,JiHyun Lee,Kyoo Hyun Kim,Hyunwook Kim,이충근,김효송,라선영,Gyu Young Pih,최윤진,정다현,박준철,신성관,이상길,이용찬,조민아,Yoo Min Kim,김형일,정재호,형우진,신재용 대한위암학회 2023 Journal of gastric cancer Vol.23 No.4

Purpose: Gastric cancer (GC) is among the most prevalent and fatal cancers worldwide. National cancer screening programs in countries with high incidences of this disease provide medical aid beneficiaries with free-of-charge screening involving upper endoscopy to detect early-stage GC. However, the coronavirus disease 2019 (COVID-19) pandemic has caused major disruptions to routine healthcare access. Thus, this study aimed to assess the impact of COVID-19 on the diagnosis, overall incidence, and stage distribution of GC. Materials and Methods: We identified patients in our hospital cancer registry who were diagnosed with GC between January 2018 and December 2021 and compared the cancer stage at diagnosis before and during the COVID-19 pandemic. Subgroup analyses were conducted according to age and sex. The years 2018 and 2019 were defined as the “before COVID” period, and the years 2020 and 2021 as the “during COVID” period. Results: Overall, 10,875 patients were evaluated; 6,535 and 4,340 patients were diagnosed before and during the COVID-19 period, respectively. The number of diagnoses was lower during the COVID-19 pandemic (189 patients/month vs. 264 patients/month) than before it. Notably, the proportion of patients with stages 3 or 4 GC in 2021 was higher among men and patients aged ≥40 years. Conclusions: During the COVID-19 pandemic, the overall number of GC diagnoses decreased significantly in a single institute. Moreover, GCs were in more advanced stages at the time of diagnosis. Further studies are required to elucidate the relationship between the COVID-19 pandemic and the delay in the detection of GC worldwide.