1.A 3D Printed Poly(e-caprolactone)-Collagen Hybrid Mesh (TissueDerm) for Breast Reconstruction after Mastectomy in a Pig Model
Kyu-Sik SHIM ; Han-Saem JO ; Shin Hyun KIM ; Dohyun KIM ; Yong-Kyu PARK ; Da-Hye RYU ; Won-Jai LEE ; Tai-Suk ROH ; Wooyeol BAEK
Tissue Engineering and Regenerative Medicine 2026;23(1):107-123
BACKGROUND:
Implant supporting materials are currently used in breast reconstruction. However, when used in humans, they are associated with several problems. To address these issues, a new mesh called TissueDerm was created by combining a collagen sponge with a 3D printed polycaprolactone (PCL) mesh. It has shown promising results in pig experiments and could potentially replace the most commonly used acellular dermal matrix (ADM) for breast reconstruction.
METHODS:
Four 12-month-old minipigs were used in this experiment. Silicone implants were wrapped with ADM or TissueDerm, and the breast tissue was excised and implanted along with the wrapped implants. Three months later, the minipigs were sacrificed and the skin and mammary gland tissue surrounding the implants were harvested for further analysis. Histological analyses and immunostaining were performed.
RESULTS:
Although there was no significant difference in capsule thickness between the ADM and TissueDerm groups, collagen was more involved in TissueDerm, leading to better tissue regeneration. TissueDerm also induced lower levels of inflammatory markers TNF-a and IL-6 compared to ADM. However, capsules induced with ADM had significantly higher collagen fiber alignment and alpha-smooth muscle actin (a-SMA) positive immunoreactivity, suggesting that TissueDerm may be less likely to cause spherical contractures in the porcine model compared to ADM.
CONCLUSIONS
The study found that TissueDerm has advantages over ADM in terms of easier tissue invasion and reduced spheroidization in a porcine model. The results showed that TissueDerm is a promising new mesh for implantbased breast reconstruction (IBBR) and could potentially replace ADM.
2.Incidental Prostate Cancer in Radical Cystectomy: Insights From the Largest Korean Cohort to Date
Young Hwii KO ; Jungmin JO ; Myung Soo KIM ; Hoyoung RYU ; Hyun Suk YOON ; Jung Hyun SHIN ; Tae Young SHIN ; Sanghui PARK ; Wan Suk KIM ; Woo Sik CHUNG ; Choung Soo KIM ; Dong Hyeon LEE
Journal of Urologic Oncology 2025;23(2):126-131
Purpose:
Incidental prostate cancer (IPCa) is frequently discovered during radical cystectomy (RC) for bladder cancer. While small-scale Korean studies have reported IPCa in 36%–50% of cases and clinically significant prostate cancer (sPCa) in up to 20%, large-scale data assessing its oncologic impact remain scarce.
Materials and Methods:
We retrospectively analyzed 1,358 male patients who underwent RC between June 1996 and January 2024. IPCa was histologically confirmed and classified per the International Society of Urological Pathology (ISUP) system. sPCa was defined as ISUP grade group (GG) ≥2. Kaplan-Meier analyses were conducted to evaluate survival outcomes.
Results:
IPCa was identified in 240 patients (17.7%), among whom 7.51% had sPCa. The distribution of ISUP GG was: GG1, 53.8%; GG2, 27.9%; GG3, 9.6%; GG4, 2.5%; and GG5, 1.7%. The proportion of sPCa remained stable across 3 time periods (p=0.281). Mean preoperative prostate-specific antigen (PSA) levels significantly differed among GG1, GG2, and GG3+ groups (2.14±2.37, 4.31±6.69, and 5.86±7.66 ng/mL, respectively; p<0.001). Mean patient age also varied significantly (67.99±8.39, 71.54±8.60, and 72.97±5.53 years; p<0.001). After a median follow-up of 44 months, deaths were unrelated to IPCa. Biochemical recurrence (BCR), defined as PSA ≥0.2 ng/mL, occurred in 11 patients (4.58%), with rates of 3.10%, 4.48%, and 12.12% in GG1, GG2, and GG3+ groups, respectively. Overall mortality rates across GG groups were similar (33.3%, 34.3%, and 33.3%; p=0.99). Compared to GG1, hazard ratios for overall survival were 1.03 (GG2, p=0.92), 0.87 (GG3, p=0.76), and 1.05 (GG4–5, p=0.89).
Conclusion
In this large Korean cohort, IPCa and sPCa were frequently detected at rates similar to global reports. Bladder cancer remained the primary determinant of survival. For older patients with elevated PSA, radical cystoprostatectomy may offer added benefit by treating undiagnosed high-risk IPCa.
3.Epidemiology and Characteristics of Ankle and Foot Injuries in Electric Scooter-Related Accidents
Tae Gyun KIM ; Jae Gyu CHOI ; Youn Moo HEO ; Jin Woong YI ; In Uk YEO ; Hyun Sik RYU ; Hyun Soo CHOI ; Jae Hwang SONG
Clinics in Orthopedic Surgery 2024;16(2):326-334
Background:
The use of electric scooters (e-scooters) continues to increase as a simple, inexpensive means of transport, resulting in a sharp increase in the incidence of scooter-related accidents. No study to date has closely examined the injury extent to the lower leg, joints, and extremities from e-scooter-related accidents. Here, we investigated the epidemiology and injury patterns of such accidents, focusing on injuries to the ankle and foot.
Methods:
Based on data from a single tertiary hospital’s database, the demographics of 563 patients with scooter-associated injuries were analyzed retrospectively. Among the patients, 229 patients who were injured by e-scooter riding were further investigated. Based on the data, the general demographics of whole scooter-associated injuries and the injury characteristics and fracture cases of the lower leg, ankle, and foot were analyzed.
Results:
During the 4-year study period, the number of patients injured by e-scooters increased every year. Lower extremities were the most common injury site (67.2%) among riders, whereas injuries to the head and neck (64.3%) were more common in riders of non-electric scooters. Among the lower leg, ankle, and foot injuries of riders (52 cases), the ankle joint (53.8%) was the most commonly injured site, followed by the foot (40.4%) and lower leg (21.2%). The fracture group scored significantly higher on the Abbreviated Injury Scale than the non-fracture group (p < 0.001). Among the fracture group (20 cases), ankle fractures (9 cases) were most common, including pronation external rotation type 4 injuries (4 cases) and pilon fractures (2 cases). Five patients (25%) had open fractures, and 12 patients (60%) underwent surgical treatment.
Conclusions
The ankle and foot are the most common injury sites in e-scooter-related accidents. Given the high frequency and severity of e-scooter-related ankle and foot injuries, we suggest that more attention be paid to preventing these types of injuries with greater public awareness of the dangers of using e-scooters.
4.Clinical Characteristics, Diagnosis, and Treatment of Thyroid Stimulating Hormone-Secreting Pituitary Neuroendocrine Tumor (TSH PitNET): A Single-Center Experience
Jung HEO ; Yeon-Lim SUH ; Se Hoon KIM ; Doo-Sik KONG ; Do-Hyun NAM ; Won-Jae LEE ; Sung Tae KIM ; Sang Duk HONG ; Sujin RYU ; You-Bin LEE ; Gyuri KIM ; Sang-Man JIN ; Jae Hyeon KIM ; Kyu Yeon HUR
Endocrinology and Metabolism 2024;39(2):387-396
Background:
Thyroid-stimulating hormone (TSH)-secreting pituitary neuroendocrine tumor (TSH PitNET) is a rare subtype of PitNET. We investigated the comprehensive characteristics and outcomes of TSH PitNET cases from a single medical center. Also, we compared diagnostic methods to determine which showed superior sensitivity.
Methods:
A total of 17 patients diagnosed with TSH PitNET after surgery between 2002 and 2022 in Samsung Medical Center was retrospectively reviewed. Data on comprehensive characteristics and treatment outcomes were collected. The sensitivities of diagnostic methods were compared.
Results:
Seven were male (41%), and the median age at diagnosis was 42 years (range, 21 to 65); the median follow-up duration was 37.4 months. The most common (59%) initial presentation was hyperthyroidism-related symptoms. Hormonal co-secretion was present in four (23%) patients. Elevated serum alpha-subunit (α-SU) showed the greatest diagnostic sensitivity (91%), followed by blunted response at thyrotropin-releasing hormone (TRH) stimulation (80%) and elevated sex hormone binding globulin (63%). Fourteen (82%) patients had macroadenoma, and a specimen of one patient with heavy calcification was negative for TSH. Among 15 patients who were followed up for more than 6 months, 10 (67%) achieved hormonal and structural remission within 6 months postoperatively. A case of growth hormone (GH)/TSH/prolactin (PRL) co-secreting mixed gangliocytoma-pituitary adenoma (MGPA) was discovered.
Conclusion
The majority of the TSH PitNET cases was macroadenoma, and 23% showed hormone co-secretion. A rare case of GH/TSH/PRL co-secreting MGPA was discovered. Serum α-SU and TRH stimulation tests showed great diagnostic sensitivity. Careful consideration is needed in diagnosing TSH PitNET. Achieving remission requires complete tumor resection. In case of nonremission, radiotherapy or medical therapy can improve the long-term remission rate.
5.Brain Frailty and Outcomes of Acute Minor Ischemic Stroke With Large-Vessel Occlusion
Je-Woo PARK ; Joon-Tae KIM ; Ji Sung LEE ; Beom Joon KIM ; Joonsang YOO ; Jung Hoon HAN ; Bum Joon KIM ; Chi Kyung KIM ; Jae Guk KIM ; Sung Hyun BAIK ; Jong-Moo PARK ; Kyusik KANG ; Soo Joo LEE ; Hyungjong PARK ; Jae-Kwan CHA ; Tai Hwan PARK ; Kyungbok LEE ; Jun LEE ; Keun-Sik HONG ; Byung-Chul LEE ; Dong-Eog KIM ; Jay Chol CHOI ; Jee-Hyun KWON ; Dong-Ick SHIN ; Sung Il SOHN ; Sang-Hwa LEE ; Wi-Sun RYU ; Juneyoung LEE ; Hee-Joon BAE
Journal of Clinical Neurology 2024;20(2):175-185
Background:
and Purpose The influence of imaging features of brain frailty on outcomes were investigated in acute ischemic stroke patients with minor symptoms and large-vessel occlusion (LVO).
Methods:
This was a retrospective analysis of a prospective, multicenter, nationwide registry of consecutive patients with acute (within 24 h) minor (National Institutes of Health Stroke Scale score=0–5) ischemic stroke with anterior circulation LVO (acute minor LVO). Brain frailty was stratified according to the presence of an advanced white-matter hyperintensity (WMH) (Fazekas grade 2 or 3), silent/old brain infarct, or cerebral microbleeds. The primary outcome was a composite of stroke, myocardial infarction, and all-cause mortality within 1 year.
Results:
In total, 1,067 patients (age=67.2±13.1 years [mean±SD], 61.3% males) were analyzed. The proportions of patients according to the numbers of brain frailty burdens were as follows: no burden in 49.2%, one burden in 30.0%, two burdens in 17.3%, and three burdens in 3.5%. In the Cox proportional-hazards analysis, the presence of more brain frailty burdens was associated with a higher risk of 1-year primary outcomes, but after adjusting for clinically relevant variables there were no significant associations between burdens of brain frailty and 1-year vascular outcomes. For individual components of brain frailty, an advanced WMH was independently associated with an increased risk of 1-year primary outcomes (adjusted hazard ratio [aHR]=1.33, 95% confidence interval [CI]=1.03–1.71) and stroke (aHR=1.32, 95% CI=1.00–1.75).
Conclusions
The baseline imaging markers of brain frailty were common in acute minor ischemic stroke patients with LVO. An advanced WMH was the only frailty marker associated with an increased risk of vascular events. Further research is needed into the association between brain frailty and prognosis in patients with acute minor LVO.
6.Varied strategies for alcohol-related liver transplants in South Korea
Hyun Hwa CHOI ; Kwang-Woong LEE ; Bong-Wan KIM ; Dong-Sik KIM ; Gyu-Seong CHOI ; Hae Won LEE ; Ho Joong CHOI ; Jaryung HAN ; Je Ho RYU ; Kwan Woo KIM ; Man Ki JU ; Min-Su PARK ; Myoung Soo KIM ; Seok-Hwan KIM ; Seoung Hoon KIM ; Shin HWANG ; Sung Won JUNG ; Tae-Seok KIM ; Woo Young SHIN
Annals of Liver Transplantation 2024;4(2):95-101
Background:
s: Alcohol-related liver disease (ALD) is currently a major indication for liver transplantation (LT) in South Korea. Alcoholic recidivism is a primary concern after LT for ALD. However, it is unclear how patients who have received LT for ALD are managed regarding medical and psychological issues. Furthermore, management approaches vary across centers. This study aims to investigate how these management approaches differ among centers.
Methods:
We conducted a survey of 19 liver transplant centers in South Korea to gather detailed information on the management protocols and related issues of ALD in LT patients.
Results:
All 19 centers that responded to the survey had been performing LT for patients with ALD for more than 5 years. Nine out of the 19 centers (47%) stated that a minimum abstinence period of 1–6 months from alcohol was required before evaluating LT and enrolling on the transplant waiting list. Only 2 (10%) and 5 (26%) centers had protocols for assessing alcohol consumption while awaiting LT or for treating alcohol consumption after transplantation, respectively. Monitoring abstinence from drinking before and after LT mostly relied on direct interviews, and alcohol biomarkers were not used.
Conclusion
Our findings emphasize the importance of consistent patient management guidelines for ALD-LTs in South Korea.
7.Visual estimation accuracy for external blood loss in diverse bleeding conditions: a comparative analysis between medical and non-medical personnel
Hye Ji LEE ; Hyun-soo CHOI ; Seung Yeon HWANG ; Seong Soo PARK ; Jae Gwang LEE ; Hyun Sik RYU ; Se Jong LEE ; Ji Eun SHIN
Journal of the Korean Society of Emergency Medicine 2023;34(6):622-630
Objective:
This study aimed to compare the accuracy of the visual estimation of blood loss between medical personnel (MP) and non-medical personnel (NP) and to evaluate how it varies with changes in the bleeding volume and environment.
Methods:
A total of 78 MP and 132 NP were recruited for the study and asked to evaluate nine artificial blood stations and three different volumes of artificial blood (192 mL, 384 mL, 768 mL) in three different environments (floor, diaper, and commode). Statistical analysis and the two-way repeated measures analysis of variance test were used for data analysis.
Results:
There were significant differences between MP and NP regardless of the actual bleeding loss in all the bleeding environments-floor (F=25.332, P<0.001), diaper (F=9.942, P=0.002), and commode (F=29.588, P<0.001). NP consistently had higher estimates of bleeding volume compared to MP. The interaction effect between group and volume was statistically significant for the floor and diaper-floor (F=9.708, P<0.001) and diaper (F=5.420, P=0.013), but there was no significant difference for the commode (P=0.087). Additionally, the standard deviation of bleeding volume estimates was higher for NP.
Conclusion
Visual estimation of blood loss differed significantly between MP and NP, with NP consistently overestimating and demonstrating lower accuracy and reliability compared to MP. These findings underscore the need for caution when relying on estimates by NP as a diagnostic tool for assessing blood loss.
8.Validation of high-sensitivity troponin I levels for major adverse cardiac events in low risk chest pain patients
Hyun Jin RYU ; Ha Young PARK ; Tae Sik HWANG ; Han Byeol KIM ; Ju Hong LEE
Journal of the Korean Society of Emergency Medicine 2023;34(6):586-598
Objective:
This study examined whether the efficiency of the level of detection (LOD) and upper reference limit (URL) for high-sensitivity cardiac troponin I (hs-cTnI) is increased when major adverse cardiovascular events (MACEs) occur in patients with low-risk chest pain who visit the emergency department (ED) and how long they stay in the ED.
Methods:
The URL for hs-cTnI used in the hospital improved from 0.04 ng/mL (LOD <0.0041 ng/mL) in 2018 to 19.8 pg/mL (LOD <2.3 pg/mL) in 2019. In these two years, the occurrence of MACEs, frequency of hs-cTnI follow-up in the ER, and the length of stay in the ER were compared. In addition, the three calculated risk assessment scores for the safety level of early discharge were compared.
Results:
In 2018, there were six MACEs out of 120 patients (5.0%), no cardiac deaths, one acute myocardial infarction (AMI), and five unplanned coronary revascularizations. In 2019, six MACEs out of 105 patients (5.7%) were all unplanned coronary revascularizations without any cardiac deaths or AMIs.
Conclusion
Although the level of hs-cTnI measurement was improved, there was no difference in the incidence of MACEs in patients with low-risk chest pain who were discharged from the ED, and the number of hs-cTnI follow-ups and time in the ED increased. Interestingly, there were only short-term MACEs and no medium-term MACEs. In addition, there was little to no coronary artery occlusion disease. The risk assessment score combined with hs-cTnI improved the predictive performance for MACEs.
9.Optimal timing for performing percutaneous transhepatic gallbladder drainage to severe acute cholecystitis patients who visit the emergency department
Jun Young CHOI ; Hyun Sik RYU ; Seong Soo PARK ; Jae Kwang LEE ; Hyun Soo CHOI ; Seung Yeon HWANG ; Ji Yeon JANG ; Se Jong LEE ; Hye Ji LEE
Journal of the Korean Society of Emergency Medicine 2023;34(1):63-69
Objective:
Severe acute cholecystitis is an infectious disease that requires immediate gallbladder drainage. Although percutaneous transhepatic gallbladder drainage (PTGBD) is the most common method of gallbladder drainage, the optimal timing remains unclear.
Methods:
This study is a retrospective analysis of patients diagnosed with severe acute cholecystitis who underwent PTGBD between July 2018 to June 2021. This study investigated the effect of time from emergency department arrival to PTGBD (tPTGBD) on patient prognosis.
Results:
Totally, 48 patients were included in this study. Based on the cutoff value calculated using the Youden index, the group with tPTGBD of <5.93 hours had a shorter hospital stay (10 vs. 13.5 days, P=0.021), lower portion of progression (27:5 [15.6%] vs. 7:9 [56.3%], P=0.004), even they had a higher initial SOFA score (6 vs. 4.6, P=0.049). However, no statistical difference was obtained for the length of ICU stay between both groups (1 vs. 2, P=0.617).
Conclusion
Executing PTGBD to severe acute cholecystitis patients within 5.93 hours after presenting at the emergency department is associated with reduced progression and hospital stay.
10.Breast Tissue Reconstruction Using Polycaprolactone Ball Scaffolds in a Partial Mastectomy Pig Model
Kyu-Sik SHIM ; Da Hye RYU ; Han-Saem JO ; Ki-Bum KIM ; Do-Hyun KIM ; Yong-Kyu PARK ; Min HEO ; Hee-Eun CHO ; Eul-Sik YOON ; Won Jai LEE ; Tai Suk ROH ; Seung Yong SONG ; Wooyeol BAEK
Tissue Engineering and Regenerative Medicine 2023;20(4):607-619
BACKGROUND:
Breast cancer patients suffer from lowered quality of life (QoL) after surgery. Breast conservancy surgery (BCS) such as partial mastectomy is being practiced and studied as an alternative to solve this problem. This study confirmed breast tissue reconstruction in a pig model by fabricating a 3-dimensional (3D) printed Polycaprolactone spherical scaffold (PCL ball) to fit the tissue resected after partial mastectomy.
METHODS:
A 3D printed Polycaprolactone spherical scaffold with a structure that can help adipose tissue regeneration was produced using computer-aided design (CAD). A physical property test was conducted for optimization. In order to enhance biocompatibility, collagen coating was applied and a comparative study was conducted for 3 months in a partial mastectomy pig model.
RESULTS:
In order to identify adipose tissue and fibroglandular tissue, which mainly constitute breast tissue, the degree of adipose tissue and collagen regeneration was confirmed in a pig model after 3 months. As a result, it was confirmed that a lot of adipose tissue was regenerated in the PCL ball, whereas more collagen was regenerated in the collagen-coated Polycaprolactone spherical scaffold (PCL–COL ball). In addition, as a result of confirming the expression levels of TNF-a and IL-6, it was confirmed that PCL ball showed higher levels than PCL–COL ball.
CONCLUSION
Through this study, we were able to confirm the regeneration of adipose tissue through a 3-dimensional structure in a pig model. Studies were conducted on medium and large-sized animal models for the final purpose of clinical use and reconstruction of human breast tissue, and the possibility was confirmed.

Result Analysis
Print
Save
E-mail