Background/Aims: The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization. Methods: The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics. Results: The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline. Conclusions This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.

Objective: Endoscopic surgery is gaining popularity as a minimally invasive option for adjacent segment degeneration (ASD). However, most of the previous literature has focused on transforaminal endoscopic techniques. This study aimed to assess the outcomes of decompressive laminectomy (unilateral laminectomy and bilateral decompression) with unilateral biportal endoscopic (UBE) in patients with lumbar ASD presenting with spinal stenosis. Methods: Thirty-nine ASD patients presenting with spinal stenosis who underwent UBE decompressive surgery between June 2018 and November 2022 at 4 different institutions were enrolled. The postoperative decompression amount and spinal instability were assessed using magnetic resonance images and dynamic radiographs. All patients were followed for at least 1 year, and clinical outcomes were assessed. Results: In the 39 patients, the cross-sectional area of the dural sac (0.55±0.21 cm2 to 1.11±0.41 cm2, p<0.001) indicated significant spinal decompression. Dynamic radiographs did not demonstrate significant occurrence of instability in operated segment. Three patients experienced complications, with one case each of hematoma, dural tear, and neurologic deficit. Visual analogue scale scores of the back (6.4±2.4 to 2.1±1.2, p<0.001) and leg (7.5±1.5 to 1.6±1.6, p<0.001), and Oswestry Disability Index scores (47.5±16.3 to 19.8±9.7, p<0.001) indicated significant clinical improvement that was sustained over 1 year. During the average follow-up period of 2 years, 2 patients underwent revision surgery due to failure and relapse. Conclusion UBE decompressive surgery had satisfactory outcomes in ASD patients, without significant failure or relapse.

Background/Aims: It remains unclear which maintenance treatment modality is most appropriate for mild gastroesophageal reflux disease (GERD).We aimed to compare on-demand treatment with continuous treatment using a proton pump inhibitor (PPI) in the maintenance treatment for patients with non-erosive GERD or mild erosive esophagitis. Methods: Patients whose GERD symptoms improved after 4 weeks of standard dose PPI treatment were prospectively enrolled at 25 hospitals.Subsequently, the enrolled patients were randomly assigned to either an on-demand or a continuous maintenance treatment group, and followed in an 8-week interval for up to 24 weeks. Results: A total of 304 patients were randomized to maintenance treatment (continuous, n = 151 vs on-demand, n = 153). The primary outcome, the overall proportion of unwillingness to continue the assigned maintenance treatment modality, failed to confirm the noninferiority of on-demand treatment (45.9%) compared to continuous treatment (36.1%). Compared with the on-demand group, the GERD symptom and health-related quality of life scores significantly more improved and the overall satisfaction score was significantly higher in the continuous treatment group, particularly at week 8 and week 16 of maintenance treatment. Work impairment scores were not different in the 2 groups, but the prescription cost was less in the on-demand group. Serum gastrin levels significantly elevated in the continuous treatment group, but not in the on-demand group. Conclusions Continuous treatment seems to be more appropriate for the initial maintenance treatment of non-erosive GERD or mild erosive esophagitis than on-demand treatment. Stepping down to on-demand treatment needs to be considered after a sufficient period of continuous treatment.

Background/Aims: The Genoss DES™ is a novel, biodegradable, polymer-coated, sirolimus-eluting stent with a cobalt- chromium stent platform and thin strut. Although the safety and effectiveness of this stent have been previously investigated, real-world clinical outcomes data are lacking. Therefore, the aim of this prospective, multicenter trial was to evaluate the clinical safety and effectiveness of the Genoss DES™ in all-comer patients undergoing percutaneous coronary intervention. Methods: The Genoss DES registry is a prospective, single-arm, observational trial for evaluation of clinical outcomes after Genoss DES™ implantation in all-comer patients undergoing percutaneous coronary intervention from 17 sites in South Korea. The primary endpoint was a device-oriented composite outcome of cardiac death, target vessel-related myocardial infarction (MI), and clinically driven target lesion revascularization (TLR) at 12 months. Results: A total of 1,999 patients (66.4 ± 11.1 years of age; 72.8% male) were analyzed. At baseline, 62.8% and 36.7% of patients had hypertension and diabetes, respectively. The implanted stent number, diameter, and length per patient were 1.5 ± 0.8, 3.1 ± 0.5 mm, and 37.0 ± 25.0 mm, respectively. The primary endpoint occurred in 1.8% patients, with a cardiac death rate of 1.1%, target vessel-related MI rate of 0.2%, and clinically driven TLR rate of 0.8%. Conclusions In this real-world registry, the Genoss DES™ demonstrated excellent safety and effectiveness at 12 months among all-comer patients undergoing percutaneous coronary intervention. These findings suggest that the Genoss DES™ may be a viable treatment option for patients with coronary artery disease.

Background/Aims: Non-celiac gluten sensitivity is characterized by intestinal and extra intestinal symptoms associated with the consumption of gluten-containing food. Since biomarkers for non-celiac gluten sensitivity are lacking, its prevalence is estimated based on self-reported symptoms. However, no data exist on self-reported non-celiac gluten sensitivity in the Korean population. Thus, we aim to investigate the prevalence of self-reported non-celiac gluten sensitivity in the Korean population and to determine its demographic and clinical characteristics. Methods: This study surveyed Korean participants aged 18-80 years who visited gastroenterology outpatient clinics at 9 tertiary hospitals in South Korea from January 2016 to February 2017. They were questioned regarding symptoms related to gluten ingestion: degree of discomfort (visual analog scale score), frequency, time of symptom onset, and duration. Abdominal discomfort caused by 11 differentkinds of gluten-containing Korean food items was investigated. Results: More non-celiac gluten sensitivity self-reporters were identified among those with irritable bowel syndrome (33.6%) than among controls (5.8%). Major gastrointestinal symptoms included bloating (75.0%), abdominal discomfort (71.3%), and belching (45.0%).Common extra-intestinal symptoms included fatigue (20.0%) and headache (13.7%). More than half of those who self-reported nonceliac gluten sensitivity (66.3%) developed symptoms within 1 hour of food ingestion, and symptoms were localized in the upper abdomen (37.5%) and entire abdomen (30.0%). Conclusion Our findings suggest that if there are gluten-related symptoms in irritable bowel syndrome, the possibility of accompanying non-celiacgluten sensitivity should be considered.

Background: Lichenoid drug eruption (LDE) is a relatively rare form of cutaneous drug eruption and that resembles lichen planus on a clinical and histological basis. Although there are some studies on histopathological findings of LDE, studies on clinical findings of LDE are limited. Objective: To investigate the clinical and histopathologic findings and prognosis of LDE. Methods: We retrospectively investigated the clinicopathologic findings of LDE patients who visited Kosin University Gospel Hospital between 1990 and 2020. Results: This study included 44 LDE patients (male:female=1.4:1). The most common causative drug was anti-tuberculous drugs (52.3%), followed by 5-fluorouracil (11.4%), and captopril (9.1%). There were pruritic erythematous scaly or lichenoid patches and plaques in all cases. The most frequently involved sites were trunk and extremities. Notably, 15 cases (34.1%) involving the scalp and 3 cases (6.8%) involving the oral mucosa. Treatment modalities included oral, topical corticosteroid, and oral antihistamines. Among 44 cases, 28 patients discontinued the causative agent, and 16 patients continued to use it after diagnosis of LDE. The mean duration of treatment for patients who discontinued or did not discontinue the causative drugs was 4, 10 weeks, respectively. The most commonly observed histopathologic findings were superficial and deep perivascular infiltration of inflammatory cells (100.0%) and eosinophil infiltration (93.2%). Conclusion LDE can be differentiated from idiopathic lichen planus by clinicopathologic findings. LDE appears to be a mild form of drug eruption in which symptoms can be controlled with conservative treatment, even without the cessation of causative drugs for the treatment of the underlying disease.

Purpose: The diagnostic performance of thyroid biopsy is influenced by several factors, including differences in the Bethesda categorization for malignancy, the inclusion or exclusion of non-diagnostic results, the definition used for the final diagnosis, and the definition of an inconclusive diagnosis. The purpose of this study was to provide an understanding of the factors influencing the diagnostic performance of thyroid biopsy. Methods: We collected data retrospectively between January and December 2013 from a cohort of 6,762 thyroid nodules from 6,493 consecutive patients who underwent biopsy. In total, 4,822 nodules from 4,553 patients were included. We calculated the biopsy sensitivity according to the inclusion of different Bethesda categories in the numerator and the exclusion of non-diagnostic results, as well as the diagnostic accuracy according to different definitions of a benign diagnosis. We obtained the conclusive and inconclusive diagnosis rates. Results: The sensitivity increased when more Bethesda categories were included in the numerator and when non-diagnostic results were excluded. When a benign thyroid nodule diagnosis was defined as benign findings on surgical resection, concordant benign results on at least two occasions, or an initial benign biopsy result and follow-up for more than 12 months, the accuracy was higher than when the diagnosis was based on surgical resection alone (68.7% vs. 91.1%). A higher conclusive diagnosis rate was obtained (78.3% vs. 72.8%, P<0.001) when Bethesda categories I and III were considered inconclusive. Conclusion Understanding the concepts presented herein is important in order to appropriately interpret the diagnostic performance of thyroid biopsy.

Oral mucosal melanoma is a very rare type of malignant melanoma, the characteristics of whichdiffer from those of cutaneous melanoma. Primary amelanotic melanoma of the mandibular gingiva,which can invade the mandibular bone, is very rare worldwide. Here, we report a case in whichwe performed a reconstruction of the mandible and gingiva using the fibula osteocutaneous freeflap procedure to treat a patient diagnosed with a primary amelanotic melanoma of the mandibulargingiva. The procedure was successful, and no recurrence was observed 10 months after surgery.Oral mucosal melanoma has a much poorer prognosis and a lower 5-year survival rate thancutaneous melanoma. However, recently, immunomodulatory therapies for mutations in melanocyticlesions have been used effectively to treat the increasing number of patients developing thistype of melanoma, thus improving the prognosis of patients with oral mucosal melanoma.

Background: : The Guideline Working Group of the Korean Society for Neuro-Oncology (KSNO)conducted the nationwide questionnaire survey for diverse queries facing to treat patients with braintumor. As part III of the survey, the aim of this study is to evaluate the national patterns of clinical practicefor patients with brain metastasis and primary central nervous system lymphoma (PCNSL). Methods: : A web-based survey was sent to all members of the KSNO by email. The survey included7 questions of brain metastasis and 5 questions of PCNSL, focused on the management strategiesin specific situations. All questions were developed by consensus of the Guideline WorkingGroup. Results: " In the survey about brain metastasis, respondents preferred surgical resection withadjuvant treatment for patients with a surgically accessible single brain metastatic lesion less than 3cm in size without extracranial systemic lesions. However, most respondents considered radiosurgeryfor surgically inaccessible lesions. As the preferred treatment of multiple brain metastases according tothe number of brain lesions, respondents tended to choose radiotherapy with increasing number of lesions.Radiosurgery was mostly chosen for the brain metastases of less than or equal to 4. In the surveyabout PCNSL, a half of respondents choose high-dose methotrexate-based polychemotherapy asthe first-line induction therapy for PCNSL. The consolidation and salvage therapy showed a little variationamong respondents. For PCNSL patients with cerebrospinal fluid dissemination, intrathecal chemotherapywas most preferred. Conclusion : The survey demonstrates the prevailing clinical practice patterns for patients withbrain metastasis and PCNSL among members of the KSNO. This information provides a point of referencefor establishing a practical guideline in the management of brain metastasis and PCNSL.