Morbid obesity requires active intervention, with treatment options including lifestyle modification, pharmacotherapy, and surgery. As the prevalence of obesity continues to rise in Korea, it is crucial for specialists and general practitioners to have a comprehensive understanding of obesity and its management. Bariatric surgery is the most effective treatment modality for obesity, leading to significant weight loss and metabolic benefits. It involves surgical alterations of normal anatomical structures to improve overall health. Therefore, selecting the appropriate procedure based on the individual characteristics of patients is crucial. This review highlights the two most commonly performed bariatric procedures worldwide, including in Korea: sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). Furthermore, it provides a comprehensive overview of the surgical techniques involved in SG and RYGB, addresses potential complications, and presents findings from key studies on the weight loss and metabolic outcomes of these surgeries. Additionally, to support clinical application, the review provides outcome data for these procedures based on studies conducted in Korean populations. In addition to SG and RYGB, this review briefly introduces other surgical and endoscopic options, as well as pharmacological treatments that are currently available or may become viable options in the near future.

Background/Aims: The kidneys and retina are highly vascularized organs that frequently exhibit shared pathologies, with nephropathy often associated with retinopathy. Previous studies have successfully predicted estimated glomerular filtration rates (eGFRs) using fundus photographs. We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas in eGFR prediction. Methods: We enrolled patients with fundus photographs and corresponding creatinine measurements taken on the same date. One photograph per eye was randomly selected, resulting in a final dataset of 45,108 patients (88,260 photographs). Data including sex, age, and blood creatinine levels were collected for eGFR calculation using the MDRD and CKD-EPI formulas. EfficientNet B3 models were used to predict each parameter. Results: Deep neural network models accurately predicted age and sex using fundus photographs. Sex was identified as a confounding variable in creatinine prediction. The MDRD formula was more susceptible to this confounding effect than the CKD-EPI formula. Notably, the CKD-EPI formula demonstrated superior performance compared to the MDRD formula (area under the curve 0.864 vs. 0.802). Conclusions Fundus photographs are a valuable tool for screening renal function using deep neural network models, demonstrating the role of noninvasive imaging in medical diagnostics. However, these models are susceptible to the influence of sex, a potential confounding factor. The CKD-EPI formula, less susceptible to sex bias, is recommended to obtain more reliable results.

Background/Aims: The clinical outcomes and optimal treatment of esophageal squamous cell carcinoma (ESCC) in elderly patients are unclear. This study aimed to assess the clinical outcomes of ESCC in patients aged ≥ 80 years. Methods: Medical records of patients diagnosed with ESCC between December 2008 and February 2024 were retrospectively reviewed. In total, 479 patients with ESCC were included and divided into the elderly (n = 52) and younger (n = 427) groups based on age. The clinical outcomes and survival rates, according to treatment, were compared between the two groups. Results: The median ages of the two groups were 82 years (range, 80–95 yr) and 66 years (41–79 yr). The overall survival was slightly lower in the elderly group; however, no statistical significance (hazard ratio [HR] 1.27, 95% confidence interval [CI] 0.85−1.91; p = 0.238) was observed. No differences were observed in the outcomes or survival between the two groups according to the treatment method (surgery, chemoradiotherapy or radiotherapy alone, and endoscopic resection). The elderly group was more likely to receive no treatment for cancer (30.8% vs. 13.6%, p = 0.002) than the younger group. However, when there was no treatment for cancer in the elderly group, survival was significantly lower than when treatment was administered (HR 0.08, 95% CI 0.03−020; p < 0.001). Conclusions In patients with ESCC aged ≥ 80 years, active cancer treatment was beneficial, and the results did not differ from those of younger patients.

Background: Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD. Methods: This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests. Results: Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030). Conclusion This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.

Background: This study evaluated adherence to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and Korean guidelines in the prescription patterns of respiratory specialists for stable chronic obstructive pulmonary disease (COPD) management. Methods: Data were collected on medications from 2011 to 2022 using the Korea COPD Subtype Study (KOCOSS) cohort. Patients were divided into two groups: those registered before and after 2019, and we analyzed the percentage of patients meeting the recommended treatment criteria established by each guideline. Results: Among 3,477 patients, 85.6% received pharmacological therapy, and 81.6% utilized inhaled medications. Compared to patients enrolled before 2019, there was an increase in inhaler prescriptions among those registered after 2019 (79.7% vs. 86.7%), with dual bronchodilators being the predominant therapy prescribed. Of the patients receiving treatment, 56.9% adhered to the Korean 2018 guideline. Compliance with the GOLD 2019 and GOLD 2023 guidelines was observed in 31.3% and 28.0% of cases, respectively. When analyzing inhaler prescription patterns according to both subgroups and considering the Korean 2018, GOLD 2019, and GOLD 2023 guidelines concurrently, the adherence rates were as follows: (56.6%, 37.8%, 24.0%) and (57.7%, 14.0%, 38.6%). Conclusion Adherence rates were higher for the Korean guideline compared to the GOLD recommendations. Furthermore, alignment with both the Korean 2018 and GOLD 2023 guidelines increased among patients enrolled after 2019, compared to those registered earlier. These findings suggest that physicians are modifying their therapeutic strategies to align with both domestic and recent international guidelines.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Background: The effectiveness of electronic medical record-based alert systems, response protocols for sepsis diagnosis, and treatment in hospitalized patients remains unclear. This study aimed to determine whether the introduction of an electronic medical record-based sepsis response protocol (SRP) along with a 24/7 operating rapid response system affects the prognosis for patients with hospital-onset sepsis. Methods: In August 2022, a SRP based on the National Early Warning Score was implemented in the electronic medical record system at Asan Medical Center. We retrospectively analyzed patients screened by the detection system for 1 year after the SRP implementation. Patients of the first 6 months (preliminary group) and those of the second 6 months (SRP group) were matched 1:1 based on propensity scores. The primary outcome was 30-day mortality. Results: Of the 608 hospitalized patients screened by the system, 176 were assigned to each group after 1:1 propensity score matching. Patients in the SRP group were significantly more likely to receive blood cultures (58.5%) compared with the preliminary group (45.5%) (P=0.019). The SRP group showed a lower 30-day mortality risk (hazard ratio, 0.56; 95% CI, 0.36–0.86; P=0.017) compared to the preliminary group. A restricted cubic spline curve showed that SRP survival benefit began to manifest after the first 4 months (P=0.036). Conclusions Alongside an existing rapid response system, the National Early Warning Score-based SRP in the electronic medical record reduced mortality for hospital-onset sepsis within 1 year.

Background: Dutasteride, a 5-alpha reductase inhibitor, is prescribed for male androgenetic alopecia (AGA) in Korea and Japan. Despite its efficacy, its use is limited by its long half-life, potent dihydrotestosterone suppression, and adverse effects. Objective: To investigate the efficacy and safety of 0.2 mg dutasteride for male AGA. Methods: Patients with male AGA were randomized to receive 0.2 mg dutasteride, placebo, or 0.5 mg dutasteride (2:2:1) once daily for 24 weeks. Safety and efficacy endpoints were assessed. Results: Overall, 139 men were analyzed. At week 24, the change in hair count within the target area at the vertex from baseline was significantly higher in the 0.2 mg dutasteride group than in the placebo group (21.53 vs. 5.96, p=0.0072). Dutasteride (0.2 mg) treatment led to greater hair growth improvement, as assessed by investigators at week 24 (p=0.0096) and an independent panel at weeks 12 and 24 (p=0.0306, p=0.0001). For all efficacy endpoints, 0.2 mg dutasteride was as effective as 0.5 mg dutasteride. The incidence of adverse events was low and not statistically different between the 0.2 mg dutasteride and placebo groups. The limitation of this study is the limited number of participants. Conclusion Low-dose (0.2 mg) dutasteride for male AGA showed significant efficacy and favorable safety profile.Trial Registration: ClinicalTrials.gov Identifier: NCT04825561

Purpose: We aimed to identify changes in surgical indications in patients with ulcerative colitis (UC) in the biologics era in a single tertiary center. Methods: In this retrospective observational study, 108 patients with UC who underwent abdominal surgery for UC at Seoul National University Hospital from 2000 to 2021 were included. We compared the total number of patients undergoing UC before and after the introduction of biologic therapy. Results: Of the 108 patients with UC (male, 59 and female, 49; mean age, 46.8 years), 30 (27.8%) underwent surgery for neoplasms and 78 (72.2%) for medical intractability without neoplasms. The duration between diagnosis and surgery varied significantly (126.00 months vs. 60.50 months, P = 0.001). A significant difference was also noted in the surgical indications according to time (P = 0.02). Between 2000 and 2010, 12 patients (19.4%) underwent surgery for UC with neoplasms and 50 (80.6%) for UC without neoplasms, while between 2011 and 2021, 18 (39.1%) and 28 patients (60.9%) underwent surgery for UC with and without neoplasms, respectively. Conclusion Since 2011, when biological agents were covered by insurance in South Korea, there has been a relative increase in the incidence of surgical indications for neoplasia cases. Focusing on closely monitoring individuals with longterm UC for neoplasms is necessary.

Biportal endoscopic spinal surgery (BESS) with interbody fusion is a relatively novel minimally invasive technique that was developed to reduce soft tissue trauma and intraoperative blood loss and shorten recovery time while achieving comparable clinical outcomes for lumbar degenerative diseases. Despite the growing interest in BESS, a comprehensive analysis of its effectiveness, complication rates, and long-term outcomes remains lacking. This systematic review evaluated the clinical outcomes, surgical efficacy, and complication rates of BESS with interbody fusion for lumbar degenerative diseases. Recent literature on endoscopic lumbar interbody fusion was included to expand the scope and gain new perspectives, thereby, providing a comparative analysis that highlighted the advantages, limitations, and emerging trends in minimally invasive spine surgery. This review synthesized current evidence to guide future research and clinical applications. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and using a combination of MeSH (Medical Subject Headings) terms and relevant keywords, PubMed/Medline and Scopus databases were systematically searched for studies published between January 2000 and September 2024. The studies were assessed using the ROBINS-I (Risk of Bias in Nonrandomized Studies of Interventions) tool to determine the risk of bias. From the 12 studies that provided clinical evidence, the data extracted were patient demographics; operative time; blood loss; clinical outcomes, such as Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores and fusion rates; and complications. The mean operative time ranged from 98 to 206 minutes, with fusion rates between 70% and 95%. Most studies reported significant improvements in VAS scores for back and leg pain and ODI scores. Complications, including dural tears (2.9%–6.4%) and hematomas (1.4%–4.3%), were infrequent but notable. BESS with interbody fusion demonstrated excellent clinical outcomes, high fusion rates, and few complications. Although these results are promising, more randomized controlled trials and long-term studies are required to confirm the broader applicability, particularly in more complex or multilevel spinal pathologies.