Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Objective: Traumatic occult pneumothorax is defined as a pneumothorax that cannot be identified with a simple chest X-ray and can be detected only by chest computed tomography (CT). The purpose of this study was to retrospectively recognize the difference between thoracostomy and conservative treatment of traumatic occult pneumothorax. Methods: Among the thoracic trauma inpatients who visited a single emergency room (ER) from January 2021 to May 2022, adult patients aged over 18 years, diagnosed with traumatic pneumothorax who survived their ER stay and with abnormalities were included as the final study subjects and their histories were compared. Results: Of the total of 269 thoracic trauma patients, 110 were diagnosed with traumatic pneumothorax, of which 30 were traumatic occult pneumothorax patients. Multiple logistic regression analyses performed in the traumatic occult pneumothorax patient group showed that as the pneumothorax size increased, the probability of finding an occult pneumothorax decreased (odds ratio [OR]=0.93; 95% confidence interval [CI], 0.89-0.98). In very severe cases of rib fractures (OR=0.65; 95% CI, 0.43-0.98), the probability of detecting occult pneumothorax was reduced. Among the patients with traumatic occult pneumothorax, 15 patients underwent thoracostomy. Cases of hemothorax (70%; P=0.05), surgery (26.67%; P<0.01), and higher injury severity scores (12.87±7.69; P=0.02) were more common in the thoracostomy group. Conclusion Usually traumatic occult pneumothorax is treated conservatively with regular follow-up, but thoracostomy is necessary when it is accompanied by hemothorax and for patients requiring surgery and having a higher injury severity score.

Objective: Traumatic occult pneumothorax is defined as a pneumothorax that cannot be identified with a simple chest X-ray and can be detected only by chest computed tomography (CT). The purpose of this study was to retrospectively recognize the difference between thoracostomy and conservative treatment of traumatic occult pneumothorax. Methods: Among the thoracic trauma inpatients who visited a single emergency room (ER) from January 2021 to May 2022, adult patients aged over 18 years, diagnosed with traumatic pneumothorax who survived their ER stay and with abnormalities were included as the final study subjects and their histories were compared. Results: Of the total of 269 thoracic trauma patients, 110 were diagnosed with traumatic pneumothorax, of which 30 were traumatic occult pneumothorax patients. Multiple logistic regression analyses performed in the traumatic occult pneumothorax patient group showed that as the pneumothorax size increased, the probability of finding an occult pneumothorax decreased (odds ratio [OR]=0.93; 95% confidence interval [CI], 0.89-0.98). In very severe cases of rib fractures (OR=0.65; 95% CI, 0.43-0.98), the probability of detecting occult pneumothorax was reduced. Among the patients with traumatic occult pneumothorax, 15 patients underwent thoracostomy. Cases of hemothorax (70%; P=0.05), surgery (26.67%; P<0.01), and higher injury severity scores (12.87±7.69; P=0.02) were more common in the thoracostomy group. Conclusion Usually traumatic occult pneumothorax is treated conservatively with regular follow-up, but thoracostomy is necessary when it is accompanied by hemothorax and for patients requiring surgery and having a higher injury severity score.

Objective: Traumatic occult pneumothorax is defined as a pneumothorax that cannot be identified with a simple chest X-ray and can be detected only by chest computed tomography (CT). The purpose of this study was to retrospectively recognize the difference between thoracostomy and conservative treatment of traumatic occult pneumothorax. Methods: Among the thoracic trauma inpatients who visited a single emergency room (ER) from January 2021 to May 2022, adult patients aged over 18 years, diagnosed with traumatic pneumothorax who survived their ER stay and with abnormalities were included as the final study subjects and their histories were compared. Results: Of the total of 269 thoracic trauma patients, 110 were diagnosed with traumatic pneumothorax, of which 30 were traumatic occult pneumothorax patients. Multiple logistic regression analyses performed in the traumatic occult pneumothorax patient group showed that as the pneumothorax size increased, the probability of finding an occult pneumothorax decreased (odds ratio [OR]=0.93; 95% confidence interval [CI], 0.89-0.98). In very severe cases of rib fractures (OR=0.65; 95% CI, 0.43-0.98), the probability of detecting occult pneumothorax was reduced. Among the patients with traumatic occult pneumothorax, 15 patients underwent thoracostomy. Cases of hemothorax (70%; P=0.05), surgery (26.67%; P<0.01), and higher injury severity scores (12.87±7.69; P=0.02) were more common in the thoracostomy group. Conclusion Usually traumatic occult pneumothorax is treated conservatively with regular follow-up, but thoracostomy is necessary when it is accompanied by hemothorax and for patients requiring surgery and having a higher injury severity score.

Objectives: The aim of this study was to determine the most effective treatment approach by comparing the impacts of various otolith reduction techniques in patients with apogeotropic lateral semicircular canal benign paroxysmal positional vertigo (LC-BPPV). Methods: We performed a multicenter randomized prospective study from January to December 2015, involving 72 consecutive patients with apogeotropic LC-BPPV. The patients were divided into three treatment groups: therapeutic head-shaking (group A), the Gufoni-Appiani maneuver (group B), and the cupulolith repositioning maneuver (CuRM; group C). Each group underwent evaluation and treatment up to the fourth week. Treatment success was defined as the disappearance of positional vertigo and nystagmus. Results: This study included 72 patients (49 male and 23 female), with a mean (±standard deviation) age of 55.4±13.5 years. The mean duration of vertigo experienced prior to treatment was 3.9±4.4 days. The mean latency and duration of nystagmus were 2.7±3.0 seconds and 47.9±15.8 seconds, respectively. The overall treatment frequency was 2.0±0.9. The number of treatments differed significantly among the three groups (P<0.05). After 4 weeks, the success rates for groups A, B, and C were 90.5%, 92.3%, and 100%, respectively. No significant difference was observed in the success rate across treatment methods and periods (P>0.05). However, CuRM was the only method with a 100% treatment success rate. Conclusion While no clear difference was observed among the three treatments for LC-BPPV, CuRM was found to be superior to the other approaches in the long term.

Purpose: Nrf2 regulates antioxidant protein expression and protects against drug toxicity and oxidative stress, whereas Keap1 controls Nrf2 activity. The Keap1-Nrf2 pathway affects the prognosis of various cancers, however, its effect on cholangiocarcinoma chemoresistance and prognosis remains unclear. This study aimed to determine whether the Keap1-Nrf2 pathway affects chemoresistance and prognosis of distal cholangiocarcinoma. Methods: We investigated the correlation between Nrf2 and Keap1 expression and clinical characteristics and prognosis in 91 patients with distal cholangiocarcinoma who underwent curative surgery. Immunohistochemical staining was performed on paraffin blocks using primary antibodies against Nrf2 and Keap1. The relationship between Keap1 and Nrf2 protein expression levels, and clinical characteristics and prognosis was examined. Results: Nrf2 expression was not associated with overall survival in patients who did not receive adjuvant chemotherapy (P=0.994). Among patients receiving adjuvant chemotherapy, the Nrf2 low expression group had a significantly longer median overall survival than the Nrf2 high expression group in Kaplan-Meier survival analysis (P=0.019). In multivariate analysis, high expression of Nrf2 was confirmed as an independent poor prognostic factor in the group receiving adjuvant chemotherapy (P=0.041). Conclusion This study suggests that Nrf2 overexpression reduces the efficacy of adjuvant chemotherapy in distal cholangiocarcinoma.

Purpose: The purpose of this study was to investigate the recurrence factors of choledocholithiasis after common bile duct (CBD) exploration. Methods: From January 2000 to December 2018, we retrospectively reviewed 253 patients who underwent CBD exploration surgery. We excluded 100 cases who had residual stone, combined major surgery, or follow-up loss after surgery. Total of 153 patients were included, and we investigated the recurrence factors of choledocholithiasis. Various variables such as patients’ demographics, gallstones, preoperative endoscopic treatment, and laboratory data were analyzed to find factors related to recurrent choledocholithiasis. Results: The median follow-up period was 20.6 months (range 4.7–219 months), and 27 patients (17.6%) had experienced recurrent choledocholithiasis. Univariate analysis showed that the following variables were associated with recurrence of choledocholithiasis; preoperative leukocytosis (white blood cell ≥ 11,000/µL), open procedure, T tube insertion, long hospital duration, and long operation time. Logistic regression multivariate analysis identified preoperative leukocytosis (odds ratio [OR], 3.43; 95% confidence interval [CI], 1.21–9.73; p = 0.021), open procedure (OR, 5.54; 95% CI, 4.73–6.35; p = 0.037), and T-tube insertion (OR, 2.82; 95% CI, 1.04–7.65; p = 0.042) as independent predictors of recurrent choledocholithiasis. Conclusion Because of delayed recurrence of choledocholithiasis, it is recommended to continue follow-up of patients after CBD exploration surgery. Laparoscopic surgery was observed to be associated with a reduction in recurrence. The preoperative leukocytosis and clinical conditions in which open surgery is performed could be associated with recurrence of choledocholithiasis. However, further study is necessary to validate the result.