1.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
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.
2.Sporopollenin-based material for prevention of postoperative adhesions: a murine study
Wei Beng NG ; Ian Ee En SIM ; Wean Sin CHEOW ; Young Jun CHAI
Annals of Surgical Treatment and Research 2025;108(4):256-269
Purpose:
This study was performed to evaluate the antiadhesive effect and safety of a novel adhesion barrier device (ABD) in comparison to other commercially available anti-adhesion products.
Methods:
A 4-arm, controlled, blinded, experimental, and murine model study design was used. Forty male Sprague Dawley rats were randomly allocated to Interceed, Seprafilm, ABD, and control groups (n = 10/group). Abdominal cavity trauma was induced in all rats. Interceed, Seprafilm, or the ABD were applied to the injury site of each rat according to their respective groups, the control group received no intervention.
Results:
Twenty-one days after the operation, surgical adhesion severity and area scores were significantly reduced in the Interceed, Seprafilm, and ABD groups compared to the control group (P = 0.016, P < 0.001, P < 0.001, respectively), and in the ABD group compared to the Interceed group (P = 0.036). No significant difference was observed between the ABD and Seprafilm groups (P = 0.070). Additionally, in the ABD group, no remnants of the ABD were observed at the injury site, and no hematological abnormalities were present.
Conclusion
The ABD has the potential to improve postsurgical peritoneal adhesions compared to Interceed and has comparable effectiveness compared to Seprafilm. The ABD may be a valuable option to reduce surgical failure. Further studies in human subjects are warranted to determine the clinical application and safety of the ABD for commercialization.
3.The safety and anti-adhesive effect of acellular dermal matrix application after thyroid surgery: a multicenter randomized controlled trial
Kwangsoon KIM ; Young Jun CHAI ; Mira HAN ; Sang-Wook KANG ; Ji-Sup YUN
Annals of Surgical Treatment and Research 2025;108(2):71-78
Purpose:
Postoperative adhesions following thyroid surgery can lead to multiple complications that significantly impact quality of life. The use of an acellular dermal matrix (ADM) adhesion barrier device has been proposed as a potential solution to reduce the risk of such adhesions. This study aimed to evaluate the safety and anti-adhesive effect of an ADM in patients undergoing thyroid surgery.
Methods:
In this multicenter randomized controlled trial, patients undergoing thyroid surgery were randomly assigned to receive either ADM (n = 42) or no ADM (n = 39) during surgery. The primary outcome was the Swallowing Impairment Score (SIS-6), measured 6 weeks after surgery and compared between groups. Secondary outcomes included intergroup comparisons of the SIS-6, the Voice Handicap Index (VHI)-10, and the Glasgow-Edinburgh Throat Scale (GETS) at baseline, and 2, 6, and 18 weeks after surgery.
Results:
At week 6, the mean SIS-6 scores were 4.0 ± 4.1 and 3.3 ± 4.2 in the ADM and control groups, respectively, which was not significantly different. Both groups showed similar postoperative improvements in SIS-6, VHI-10, and GETS scores over time, without significant differences between groups at any time point, indicating that the ADM did not reduce the incidence of postoperative adhesions or alter the course of recovery compared to the control group.
Conclusion
Although application of the ADM is safe for use in patients undergoing thyroid surgery, it did not produce a clinically significant advantage in preventing postoperative adhesions. Future research should focus on identifying specific patient populations or surgical scenarios where the use of the ADM may be beneficial.
4.Enhancing recurrent laryngeal nerve localization during transoral endoscopic thyroid surgery using augmented reality: a proof-of-concept study
Moon Young OH ; Yeonjin CHOI ; Taesoo JANG ; Eun Kyung CHOE ; Hyoun-Joong KONG ; Young Jun CHAI
Annals of Surgical Treatment and Research 2025;108(3):135-142
Purpose:
During transoral endoscopic thyroidectomy, preserving the recurrent laryngeal nerve (RLN) is a major challenge because visualization of this nerve is often obstructed by the thyroid itself, increasing the risk of serious complications.This study explores the application of an augmented reality (AR) system to facilitate easier identification of the RLN during transoral endoscopic thyroidectomy.
Methods:
Three patients scheduled for transoral endoscopic thyroidectomy were enrolled in this proof-of-concept study. Preoperative computed tomography scans were used to create an AR model that included the thyroid, trachea, veins, arteries, and RLN. The model was overlaid onto real-time endoscopic camera images during live surgeries.Manual registration of the AR model was performed using a customized controller. The model was aligned with surgical landmarks such as the trachea and common carotid artery. Manual registration accuracy was assessed using the Dice similarity coefficient (DSC) to evaluate the alignment between the real RLN and the RLN of the AR model.
Results:
The 3 patients included were female (mean age, 33.3 ± 15.7 years), and the mean tumor size was 1.0 ± 0.3 cm. All patients underwent transoral endoscopic thyroidectomy of the right lobe. Final histopathological diagnoses comprised 2 papillary thyroid carcinomas and one follicular adenoma. The manual registration accuracy was 0.60, 0.70, and 0.57 for patients 1, 2, and 3, respectively, with a mean value of 0.6 ± 0.1.
Conclusion
The application of an AR system during transoral endoscopic thyroidectomy proved feasible and demonstrated potential for improving the localization of anatomical structures, particularly the RLN, as indicated by a moderate DSC.
5.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
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.
6.Sporopollenin-based material for prevention of postoperative adhesions: a murine study
Wei Beng NG ; Ian Ee En SIM ; Wean Sin CHEOW ; Young Jun CHAI
Annals of Surgical Treatment and Research 2025;108(4):256-269
Purpose:
This study was performed to evaluate the antiadhesive effect and safety of a novel adhesion barrier device (ABD) in comparison to other commercially available anti-adhesion products.
Methods:
A 4-arm, controlled, blinded, experimental, and murine model study design was used. Forty male Sprague Dawley rats were randomly allocated to Interceed, Seprafilm, ABD, and control groups (n = 10/group). Abdominal cavity trauma was induced in all rats. Interceed, Seprafilm, or the ABD were applied to the injury site of each rat according to their respective groups, the control group received no intervention.
Results:
Twenty-one days after the operation, surgical adhesion severity and area scores were significantly reduced in the Interceed, Seprafilm, and ABD groups compared to the control group (P = 0.016, P < 0.001, P < 0.001, respectively), and in the ABD group compared to the Interceed group (P = 0.036). No significant difference was observed between the ABD and Seprafilm groups (P = 0.070). Additionally, in the ABD group, no remnants of the ABD were observed at the injury site, and no hematological abnormalities were present.
Conclusion
The ABD has the potential to improve postsurgical peritoneal adhesions compared to Interceed and has comparable effectiveness compared to Seprafilm. The ABD may be a valuable option to reduce surgical failure. Further studies in human subjects are warranted to determine the clinical application and safety of the ABD for commercialization.
7.The safety and anti-adhesive effect of acellular dermal matrix application after thyroid surgery: a multicenter randomized controlled trial
Kwangsoon KIM ; Young Jun CHAI ; Mira HAN ; Sang-Wook KANG ; Ji-Sup YUN
Annals of Surgical Treatment and Research 2025;108(2):71-78
Purpose:
Postoperative adhesions following thyroid surgery can lead to multiple complications that significantly impact quality of life. The use of an acellular dermal matrix (ADM) adhesion barrier device has been proposed as a potential solution to reduce the risk of such adhesions. This study aimed to evaluate the safety and anti-adhesive effect of an ADM in patients undergoing thyroid surgery.
Methods:
In this multicenter randomized controlled trial, patients undergoing thyroid surgery were randomly assigned to receive either ADM (n = 42) or no ADM (n = 39) during surgery. The primary outcome was the Swallowing Impairment Score (SIS-6), measured 6 weeks after surgery and compared between groups. Secondary outcomes included intergroup comparisons of the SIS-6, the Voice Handicap Index (VHI)-10, and the Glasgow-Edinburgh Throat Scale (GETS) at baseline, and 2, 6, and 18 weeks after surgery.
Results:
At week 6, the mean SIS-6 scores were 4.0 ± 4.1 and 3.3 ± 4.2 in the ADM and control groups, respectively, which was not significantly different. Both groups showed similar postoperative improvements in SIS-6, VHI-10, and GETS scores over time, without significant differences between groups at any time point, indicating that the ADM did not reduce the incidence of postoperative adhesions or alter the course of recovery compared to the control group.
Conclusion
Although application of the ADM is safe for use in patients undergoing thyroid surgery, it did not produce a clinically significant advantage in preventing postoperative adhesions. Future research should focus on identifying specific patient populations or surgical scenarios where the use of the ADM may be beneficial.
8.Enhancing recurrent laryngeal nerve localization during transoral endoscopic thyroid surgery using augmented reality: a proof-of-concept study
Moon Young OH ; Yeonjin CHOI ; Taesoo JANG ; Eun Kyung CHOE ; Hyoun-Joong KONG ; Young Jun CHAI
Annals of Surgical Treatment and Research 2025;108(3):135-142
Purpose:
During transoral endoscopic thyroidectomy, preserving the recurrent laryngeal nerve (RLN) is a major challenge because visualization of this nerve is often obstructed by the thyroid itself, increasing the risk of serious complications.This study explores the application of an augmented reality (AR) system to facilitate easier identification of the RLN during transoral endoscopic thyroidectomy.
Methods:
Three patients scheduled for transoral endoscopic thyroidectomy were enrolled in this proof-of-concept study. Preoperative computed tomography scans were used to create an AR model that included the thyroid, trachea, veins, arteries, and RLN. The model was overlaid onto real-time endoscopic camera images during live surgeries.Manual registration of the AR model was performed using a customized controller. The model was aligned with surgical landmarks such as the trachea and common carotid artery. Manual registration accuracy was assessed using the Dice similarity coefficient (DSC) to evaluate the alignment between the real RLN and the RLN of the AR model.
Results:
The 3 patients included were female (mean age, 33.3 ± 15.7 years), and the mean tumor size was 1.0 ± 0.3 cm. All patients underwent transoral endoscopic thyroidectomy of the right lobe. Final histopathological diagnoses comprised 2 papillary thyroid carcinomas and one follicular adenoma. The manual registration accuracy was 0.60, 0.70, and 0.57 for patients 1, 2, and 3, respectively, with a mean value of 0.6 ± 0.1.
Conclusion
The application of an AR system during transoral endoscopic thyroidectomy proved feasible and demonstrated potential for improving the localization of anatomical structures, particularly the RLN, as indicated by a moderate DSC.
9.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
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.
10.Sporopollenin-based material for prevention of postoperative adhesions: a murine study
Wei Beng NG ; Ian Ee En SIM ; Wean Sin CHEOW ; Young Jun CHAI
Annals of Surgical Treatment and Research 2025;108(4):256-269
Purpose:
This study was performed to evaluate the antiadhesive effect and safety of a novel adhesion barrier device (ABD) in comparison to other commercially available anti-adhesion products.
Methods:
A 4-arm, controlled, blinded, experimental, and murine model study design was used. Forty male Sprague Dawley rats were randomly allocated to Interceed, Seprafilm, ABD, and control groups (n = 10/group). Abdominal cavity trauma was induced in all rats. Interceed, Seprafilm, or the ABD were applied to the injury site of each rat according to their respective groups, the control group received no intervention.
Results:
Twenty-one days after the operation, surgical adhesion severity and area scores were significantly reduced in the Interceed, Seprafilm, and ABD groups compared to the control group (P = 0.016, P < 0.001, P < 0.001, respectively), and in the ABD group compared to the Interceed group (P = 0.036). No significant difference was observed between the ABD and Seprafilm groups (P = 0.070). Additionally, in the ABD group, no remnants of the ABD were observed at the injury site, and no hematological abnormalities were present.
Conclusion
The ABD has the potential to improve postsurgical peritoneal adhesions compared to Interceed and has comparable effectiveness compared to Seprafilm. The ABD may be a valuable option to reduce surgical failure. Further studies in human subjects are warranted to determine the clinical application and safety of the ABD for commercialization.

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