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.

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.

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.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: The proximal humerus, a common site for osteoporotic fractures, is frequently overlooked in osteoporosis evaluations. This study aimed to evaluate the relationship between the conventional bone mineral density (BMD) measurement (at the lumbar spine and femur) and the BMD measurement at both proximal humeri (the asymptomatic side and the side with a rotator cuff tear [RCT]) in patients with unilateral RCT. Furthermore, we investigated clinical features indicative of osteoporosis in RCT patients and assessed the utility of proximal humerus BMD measurements. Methods: From April 2020 to September 2020, 87 patients who underwent arthroscopic repairs for unilateral RCTs were examined for age, onset, body mass index, menopause duration, passive range of motion, global fatty degeneration index, and RCT and retraction size. The regions of interest (ROIs) for the conventional BMD included the lumbar spine, femur neck, femur trochanter, and total femur. For the proximal humerus BMD, the ROIs included the head, lesser tuberosity, greater tuberosity (medial, middle, and lateral rows), and total humerus. Results: The conventional BMD of the lumbar spine, femur neck, femur trochanter, and femur total were 1.090, 0.856, 0.781, and 0.945 g/cm2 , respectively. The head, lesser tuberosity, greater tuberosity (medial, middle, and lateral rows), and total BMD of the asymptomatic-side proximal humerus were 0.547, 0.544, 0.697, 0.642, 0.554, and 0.610 g/cm2 , respectively. The average of proximal humerus BMD was significantly lower than that of conventional BMD (p < 0.001). All ROIs BMD of the RCT-side proximal humerus were 0.497, 0.507, 0.619, 0.598, 0.517, and 0.560 g/cm2 . There was no correlation between the conventional BMD and each proximal humerus BMD. All ROI BMD of the RCT-side proximal humerus was not significant in the multiple regression analysis with age, onset, body mass index, passive range of motion, global fatty degeneration index, and RCT and retraction size (p > 0.05). Conclusions The proximal humerus BMD showed a completely different trend from that of conventional BMD and had no significant association with clinical features. Therefore, the proximal humerus BMD needs to be measured separately from the conventional BMD, as it may provide important information before rotator cuff repair surgery.

The Korean Triage and Acuity Scale (KTAS) Committee under the Korean Society of Emergency Medicine developed a Korean pre-hospital emergency patient classification tool (Pre-hospital Korean Triage and Acuity Scale [Pre-KTAS]) under contract from the Ministry of Health and Welfare, Korea. The classification tool was developed separately for adults and children. The patient’ s emergency level is classified into five distinct levels and is the same as the KTAS classification system, which is a hospital-level emergency patient classification tool.

Purpose: Circulating tumor DNA (ctDNA) is emerging as a valuable non-invasive tool to identify tumor heterogeneity and tumor burden. This study investigated ctDNA dynamics in metastatic colorectal cancer patients treated with regorafenib. Materials and Methods: In this prospective biomarker study, plasma cell-free DNA (cfDNA) samples obtained at baseline, at the first response evaluation after 2 cycles of treatment, and at the time of progressive disease were sequenced using a targeted next-generation sequencing platform which included 106 genes. Results: A total of 285 blood samples from 110 patients were analyzed. Higher baseline cfDNA concentration was associated with worse progression-free survival (PFS) and overall survival (OS). After 2 cycles of treatment, variant allele frequency (VAF) in the majority of ctDNA mutations decreased with a mean relative change of –31.6%. Decreases in the VAF of TP53, APC, TCF7L2, and ROS1 after 2 cycles of regorafenib were associated with longer PFS. We used the sum of VAF at each time point as a surrogate for the overall ctDNA burden. A reduction in sum (VAF) of ≥ 50% after 2 cycles was associated with longer PFS (6.1 vs. 2.7 months, p=0.002), OS (11.3 vs. 5.9 months, p=0.001), and higher disease control rate (86.3% vs. 51.1%, p < 0.001). VAF of the majority of the ctDNA mutations increased at the time of disease progression, and VAF of BRAF increased markedly. Conclusion Reduction in ctDNA burden as estimated by sum (VAF) could be used to predict treatment outcome of regorafenib.