Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Background/Aims: Although endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) are widely used for tissue acquisition of pancreatic solid mass, the optimal strategy of this procedure has not been established yet. The aim of this nationwide study was to investigate the current practice patterns of EUS-FNA/FNB for pancreatic solid mass in Korea. Methods: The Policy-Quality Management of the Korean Pancreatobiliary Association (KPBA) developed a questionnaire containing 22 questions. An electronic survey consisting of the questionnaire was distributed by e-mail to members registered to the KPBA. Results: A total of 101 respondents completed the survey. Eighty respondents (79.2%) performed preoperative EUS-FNA/FNB for operable pancreatic solid mass. Acquire needles (60.4%) were used the most, followed by ProCore needles (47.5%). In terms of need size, most respondents (>80%) preferred 22-gauge needles regardless of the location of the mass. Negative suction with a 10-mL syringe (71.3%) as sampling technique was followed by stylet slow-pull (41.6%). More than three needle passes for EUS-FNA/FNB was performed by most respondents (>80%). The frequency of requiring repeated procedure was significantly higher in respondents with a low individual volume (<5 per month, p=0.001). Prophylactic antibiotics were routinely used in 39 respondents (38.6%); rapid on-site pathologic evaluation was used in 6.1%. Conclusions According to this survey, practices of EUS-FNA/FNB for pancreatic solid mass varied substantially, some of which differed considerably from the recommendations present in existing guidelines. These results suggest that the development of evidence-based quality guidelines fitting Korean clinical practice is needed to establish the optimal strategy for this procedure.

Background/Aims: This study aimed to investigate the patterns of preferred endoscopic procedure types and techniques for managing difficult common bile duct (CBD) stones in South Korea. Methods: The Committee of Policy and Quality Management of Korean Pancreatobiliary Association (KPBA) conducted a survey containing 19 questions. Both paper and online surveys were carried out; with the paper survey being conducted during the 2019 Annual Congress of KPBA and the online survey being conducted through Google Forms from April 2020 to February 2021. Results: The response rate was approximately 41.3% (86/208). Sixty-two (73.0%) worked at tertiary hospitals or academic medical centers, and 60 (69.7%) had more than 5 years of endoscopic retrograde cholangiopancreatography experience. The preferred size criteria for large CBD stones were 15 mm (40.6%), 20 mm (31.3%), and 30 mm (4.6%). For managing of large CBD stones, endoscopic papillary large balloon dilation after endoscopic sphincterotomy was the most preferred technique (74.4%). When performing procedures in those with bleeding diathesis, 64 (74.4%) respondents favored endoscopic papillary balloon dilation (EPBD) alone or EPBD with small endoscopic sphincterotomy. Fifty-five respondents (63.9%) preferred the doubleguidewire technique when faced with difficult bile duct cannulation in patients with periampullary diverticulum. In surgically altered anatomies, cap-fitted forward viewing endoscopy (76.7%) and percutaneous transhepatic cholangioscopy (48.8%) were the preferred techniques for Billroth-II anastomosis and total gastrectomy with Roux-en-Y anastomosis, respectively. Conclusions Most respondents showed unifying trends for the management of difficult CBD stones. The current practice patterns could be used as basic data for clinical quality improvements in the management of difficult CBD stones.

The purpose of this study was to evaluate the structural characteristics of the thread length of orthodontic mini-screws and the effects of insertion and removal torques according to the formation of the cutting flute. Two types of mini-screws were made, with a thread length of 6.0 mm and a thread length of 3.3 mm. In order to examine the effect of flute formation, the experiment group was divided into a miniscrew test group with flute formation and an experiment group without flute formation. To evaluate the effect of flute formation, two flutes were formed at 180°on the circumference, and at the tip of the mini screw, up to 4 mm for thread length of 6.0 mm and 2.4 mm for thread length of 3.3 mm. A biomechanical test block formed of 2 mm cortical bone and 10 mm cancellous bone was used to eliminate the influence of the difference in cortical bone thickness and bone density according to the insertion site. 1 mm diameter guide hole was drilled on the test block and the mini-screw was placed vertically. Using a 0.1 N·cm precision digital torque gauge, the maximum torque value was recorded at this time by embedding it to the top of the screw under a static load of 1.2 kg and the value when it was removed in the opposite direction. The insertion torque values for the 6.0 mm and 3.3 mm length mini screws were (29.53±1.84) N·cm and (26.84±2.15) N·cm, and the removal torque values are (14.50±1.37) N·cm and (13.15±2.89) N·cm, respectively.There were no statistically significant differences (P>0.05). The flute of 6.0 mm mini-screws had no statistically significant difference in both insertion and removal torque values and increased to (30.13±1.97) N·cm and (18.65±1.10) N·cm (P>0.05). In experiments with 3.3 mm mini-screws, the insertion and removal torque values decreased to (20.99±3.94) N·cm and (11.32±2.03) N·cm, respectively, showing a statistically significant decrease only in the insertion torque values (P<0.05). The insertion and removal torque values of the mini-screw were not significantly increased even when the screw length was doubled, and the flute formation effect was different with the screw length.

The purpose of this study was to evaluate the structural characteristics of the thread length of orthodontic mini-screws and the effects of insertion and removal torques according to the formation of the cutting flute. Two types of mini-screws were made, with a thread length of 6.0 mm and a thread length of 3.3 mm. In order to examine the effect of flute formation, the experiment group was divided into a miniscrew test group with flute formation and an experiment group without flute formation. To evaluate the effect of flute formation, two flutes were formed at 180°on the circumference, and at the tip of the mini screw, up to 4 mm for thread length of 6.0 mm and 2.4 mm for thread length of 3.3 mm. A biomechanical test block formed of 2 mm cortical bone and 10 mm cancellous bone was used to eliminate the influence of the difference in cortical bone thickness and bone density according to the insertion site. 1 mm diameter guide hole was drilled on the test block and the mini-screw was placed vertically. Using a 0.1 N·cm precision digital torque gauge, the maximum torque value was recorded at this time by embedding it to the top of the screw under a static load of 1.2 kg and the value when it was removed in the opposite direction. The insertion torque values for the 6.0 mm and 3.3 mm length mini screws were (29.53±1.84) N·cm and (26.84±2.15) N·cm, and the removal torque values are (14.50±1.37) N·cm and (13.15±2.89) N·cm, respectively.There were no statistically significant differences (P>0.05). The flute of 6.0 mm mini-screws had no statistically significant difference in both insertion and removal torque values and increased to (30.13±1.97) N·cm and (18.65±1.10) N·cm (P>0.05). In experiments with 3.3 mm mini-screws, the insertion and removal torque values decreased to (20.99±3.94) N·cm and (11.32±2.03) N·cm, respectively, showing a statistically significant decrease only in the insertion torque values (P<0.05). The insertion and removal torque values of the mini-screw were not significantly increased even when the screw length was doubled, and the flute formation effect was different with the screw length.

BACKGROUND: Corneal scarring or disease may lead to severe corneal opacification and consequently, severe loss of vision due to the complete loss of corneal epithelial cells. We studied the use of epithelial cell sheets differentiated from fetal cartilage-derived stem cells (FCSC) to resurface damaged cornea. METHODS: The FCSC were isolated from the femoral head of immature cartilage tissue. The ability of the FCSCs to differentiate into corneal epithelial cells was evaluated using differentiation media at 2 days and 7 days post-seeding. A sheet fabricated of FCSCs was also used for the differentiation assay. The results of the in vitro studies were evaluated by immunocytochemistry and Western blots for corneal epithelial cell markers (CK3/12 and Pax6) and limbal epithelial stem cell markers (ABCG2 and p63). To test the material in vivo, an FCSC-sheet was applied as a treatment in a chemically burned rabbit model. The healing ability was observed histologically one week after treatment. RESULTS: The in vitro experiments showed morphological changes in the FCSCs at two and seven days of culture. The differentiated cells from the FCSCs or the FCSC-sheet expressed corneal epithelial cells markers. FCSC were create cell sheet that successfully differentiated into corneal epithelial cells and had sufficient adhesion so that it could be fused to host tissue after suture to the ocular surface with silk suture. The implanted cell sheet maintained its transparency and the cells were alive a week after implantation. CONCLUSION These results suggest that carrier-free sheets fabricated of FCSCs have the potential to repair damaged corneal surfaces.

BACKGROUND: Corneal scarring or disease may lead to severe corneal opacification and consequently, severe loss of vision due to the complete loss of corneal epithelial cells. We studied the use of epithelial cell sheets differentiated from fetal cartilage-derived stem cells (FCSC) to resurface damaged cornea. METHODS: The FCSC were isolated from the femoral head of immature cartilage tissue. The ability of the FCSCs to differentiate into corneal epithelial cells was evaluated using differentiation media at 2 days and 7 days post-seeding. A sheet fabricated of FCSCs was also used for the differentiation assay. The results of the in vitro studies were evaluated by immunocytochemistry and Western blots for corneal epithelial cell markers (CK3/12 and Pax6) and limbal epithelial stem cell markers (ABCG2 and p63). To test the material in vivo, an FCSC-sheet was applied as a treatment in a chemically burned rabbit model. The healing ability was observed histologically one week after treatment. RESULTS: The in vitro experiments showed morphological changes in the FCSCs at two and seven days of culture. The differentiated cells from the FCSCs or the FCSC-sheet expressed corneal epithelial cells markers. FCSC were create cell sheet that successfully differentiated into corneal epithelial cells and had sufficient adhesion so that it could be fused to host tissue after suture to the ocular surface with silk suture. The implanted cell sheet maintained its transparency and the cells were alive a week after implantation. CONCLUSION These results suggest that carrier-free sheets fabricated of FCSCs have the potential to repair damaged corneal surfaces.

The purpose of this study was to evaluate the effect of the reaction between investment material and zirconia on the strength of zirconia in the application of heat-pressing method. Sixty specimens were cut (24 mm×4 mm×0.5 mm) into plates from Zirtooth ™ Multi O-9814 block (∅98×14T, HASS, Gangwondo, Korea) and sintered at 1450℃. Specimens were divided into 6 subgroups according to the depending on the investement material; (a) UN group (Control), (b) PH group (Prime vest HS), (c) CP group (Calibra-press), (d) BV group (BC-Vest), (e) MH group (Microstar-HS), (f) F1 group (Formula 1). Five investment materials were buried according to the procedure recommended by the manufacturer and left at room temperature for 30 minutes. The investment mold was dried and maintained at an elevated temperature of 850℃ for 50 minutes. Then, Amber Lisi-POZ LT (HASS) was placed in a thermoformed electric furnace (Programat EP3000/G2, Ivoclar Vivadent, Schaan, Liechtenstein) together with the mold, heated to 915℃ at an elevation temperature of 45℃/min, and moored for 15 minutes. The specimens were loaded to fracture in a universal testing machine and the fracture surface was examined by a field-emission scanning electron microscopy (FE-SEM). The surface of the zirconia specimen with the investment material was analyzed by energy dispersive X-ray spectroscopy (EDS). The 3-point flexural strength test showed the highest value (1265.5 MPa) in the UN group and the lowest value (756.1 MPa) in the F1 group. As a result of EDS analysis, the largest amount of Si was detected in the F1 group, and the most interfacial changes occurred as a result of FE-SEM analysis. It was concluded that when the zirconia is buried with the investment material and the heat press molding is performed, the state of the interface is changed due to the investment material at the bonding interface while the strength is lowered.