• Toxicological Research
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• 제35권4호
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• pp.395-402
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• 2019

Subcutaneous adipose tissue (SAT) accumulation is a constitutional disorder resulting from metabolic syndrome. Although surgical and non-surgical methods for reducing SAT exist, patients remain non-compliant because of potential adverse effects and cost. In this study, we developed a new minimally-invasive approach to achieve SAT reduction, using a microneedle (MN) patch prepared from gelatin, which is capable of regulating fat metabolism. Four gelatin types were used: three derived from fish (SA-FG, GT-FG 220, and GT-FG 250), and one from swine (SM-PG 280). We applied gelatin-based MN patches five times over 4 weeks to rats with high-fat diet (HD)-induced obesity, and determined the resulting amount of SAT. We also investigated the histological features and determined the expression levels of fat metabolism-associated genes in SAT using hematoxylin and eosin staining and western blotting, respectively. SAT decreased following treatment with all four gelatin MN patches. Smaller adipocytes were observed in the regions treated with SA-FG, GT-FG 250, and SM-PG 280 MNs, demonstrating a decline in fat accumulation. The expression levels of fat metabolism-associated genes in the MN-treated SAT revealed that GT-FG 220 regulates fatty acid synthase (FASN) protein levels. These findings suggest that gelatin MN patches aid in decreasing the quantity of unwanted SAT by altering lipid metabolism and fat deposition.

• 대한치과의사협회지
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• 제56권11호
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• pp.631-640
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• 2018

Nowadays computer-guided "flapless" surgery for implant placement using templates is gaining popularity among clinicians and patients. The advantages of this surgical protocol are its minimally invasive nature, accuracy of implant placement, predictability, less post-surgical discomfort and reduced time required for definitive rehabilitation. Aim of this study is to describe the digital implant protocol, thanks to which is now possible to do a mini-invasive static guided implant surgery. This is possible thanks to a procedure named surface mapping based on the matching between numerous points on the surface of patient's dental casts and the corresponding anatomical surface points in the CBCT data. With some critical points and needing an adequate learning curve, this protocol allows to select the ideal implant position in depth, inclination and mesio-distal distance between natural teeth and or other implants enabling a very safe and predictable rehabilitation compared with conventional surgery. It represents a good tool for the best compromise between anatomy, function and aesthetic, able to guarantee better results in all clinical situations.

• Journal of Minimally Invasive Surgery
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• 제21권4호
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• pp.148-153
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• 2018

Purpose: Single incision laparoscopic appendectomy (SILA) is a widely used surgical procedure for treatment of appendicitis with better cosmesis. However, many surgeons generally tend to choose conventional multiport laparoscopic appendectomy regarding with complicated appendicitis. The aim of this study is to demonstrate the safety and feasibility of SILA for treatment of complicated appendicitis by comparison with 3-ports conventional laparoscopic appendectomy (CLA). Methods: Retrospective chart review of patients diagnosed appendicitis at single hospital during January 2015 to May 2017 collected 500 patients. Among 134 patients with complicated appendicitis, we compared outcomes for 29 patients who got SILA and 105 patients who got CLA. Results: 179 and 321 patients were treated by SILA and CLA, respectively. 134 (26.8%) patients were treated for complicated appendicitis, 29 patients by SILA and 105 patients by CLA, respectively. There was no case converted to open or added additional trocar in both groups. There were no differences in demographics with regard to age, sex, body mass index (BMI), and American society of anesthesiologists (ASA) scores. There was no difference in mean operating time ($58.97{\pm}18.53$ (SILA) vs. $57.57{\pm}21.48$ (CLA), p=0.751). The drain insertion rate (6.9% vs 37.1%, p=0.001) and the length of hospital stay ($2.76{\pm}1.41$ vs. $3.97{\pm}2.97$, p=0.035) were lower in SILA group with significance. There was no significant difference in the rate of surgical site infection (6.9% vs. 6.7%, p=1.000). Conclusion: This study demonstrates that SILA is a feasible and safe procedure for treatment of complicated appendicitis.

• Journal of Minimally Invasive Surgery
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• 제21권4호
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• pp.154-159
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• 2018

Purpose: Intussusception is a common cause of intestinal obstruction in children. While most patients can be treated by enema reduction, about 20% require surgery. We investigated the usefulness and feasibility of laparoscopic surgery and the intraoperative risk of bowel resection. Methods: We retrospectively reviewed pediatric patients who underwent surgery for intussusception from 2010 to 2017. We collected data for age, gender, body weight, associated symptoms, duration of symptoms, white blood cell count, operating time, and postoperative complications. Results: Of 155 patients, 37 (23.8%) underwent surgery due to enema reduction failure in 29 (78.3%), recurrence in 6 (16.3%), a suspicious lead point in 1, and suspicious ischemic change observed on ultrasonography in 1. The mean age was $26.8{\pm}18.9$ months (range, 3.5~76.7 months), and the mean body weight was $12.9{\pm}3.9kg$ (range, 5.4~22.2 kg). Laparoscopic surgery was successful in 29 patients (78.4%), and 7 (18.9%) needed bowel resection and anastomosis. The mean operating time was $56.7{\pm}32.8min$. A lead point was found in 3 patients in the bowel resection group (p=0.005); in addition, the operating time and hospital stay were longer in this group. There were no intra- or postoperative complications. Conclusion: Laparoscopic surgery was successful in 78.4% of the patients with a short hospital stay and early oral intake. The only predictive factor for bowel resection was the presence of a lead point. Laparoscopic surgery may be an optimal treatment intervention for children with intussusception, except for those who show initial peritonitis.

• Archives of Plastic Surgery
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• 제48권3호
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• pp.323-328
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• 2021

Background Lymphaticovenular anastomosis (LVA) is a minimally invasive surgical procedure used to treat lymphedema. Volumetric measurements and quality-of-life assessments are often performed to assess the effectiveness of LVA, but there is no method that provides information regarding postoperative morphological changes in lymphatic vessels and veins after LVA. Photoacoustic lymphangiography (PAL) is an optical imaging technique that visualizes the distribution of light-absorbing molecules, such as hemoglobin or indocyanine green (ICG), and provides three-dimensional images of superficial lymphatic vessels and the venous system simultaneously. In this study, we performed PAL in lymphedema patients before and after LVA and compared the images to evaluate the effect of LVA. Methods PAL was performed using the PAI-05 system in three patients (one man, two women) with lymphedema, including one primary case and two secondary cases, before LVA. ICG fluorescence lymphography was performed in all cases before PAL. Follow-up PAL was performed between 5 days and 5 months after LVA. Results PAL enabled the simultaneous visualization of clear lymphatic vessels that could not be accurately seen with ICG fluorescence lymphography and veins. We were also able to observe and analyze morphological changes such as the width and the number of lymphatic vessels and veins during the follow-up PAL after LVA. Conclusions By comparing preoperative and postoperative PAL images, it was possible to analyze the morphological changes in lymphatic vessels and veins that occurred after LVA. Our study suggests that PAL would be useful when assessing the effect of LVA surgery.

• Journal of Gastric Cancer
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• 제20권4호
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• pp.431-441
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• 2020

Purpose: Various studies have indicated that reduced-port robotic gastrectomies are safe and feasible for treating patients with early gastric cancer. However, there have not been any comparative studies conducted that have evaluated patients with clinically advanced gastric cancer. Therefore, we aimed to compare the perioperative outcomes of D2 lymph node dissections during reduced-port robotic distal subtotal gastrectomies (RRDGs) and conventional 5-port laparoscopic distal subtotal gastrectomies (CLDGs). Materials and Methods: We retrospectively evaluated 118 patients with clinically advanced gastric cancer who underwent minimally invasive distal subtotal gastrectomies with D2 lymph node dissections between February 2016 and November 2019. To evaluate the patient data, we performed a 1:1 propensity score matching (PSM) according to age, sex, body mass index, American Society of Anesthesiologists physical status classification score, and clinical T status. The short-term surgical outcomes were also compared between the two groups. Results: The PSM identified 40 pairs of patients who underwent RRDG or CLDG. The RRDG group experienced a significantly longer operation time than the CLDG group (P<0.001), although the RRDG group had significantly less estimated blood loss (P=0.034). The number of retrieved extraperigastric lymph nodes in the RRDG group was significantly higher than that of the CLDG group (P=0.008). The rate of postoperative complications was not significantly different between the two groups (P=0.115). Conclusions: D2 lymph node dissections can be safely performed during RRDGs and the perioperative outcomes appear to be comparable to those of conventional laparoscopic surgeries. Further studies are needed to compare long-term survival outcomes.

• Journal of Gastric Cancer
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• 제20권4호
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• pp.385-394
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• 2020

Purpose: Patients with gastric cancer who receive neoadjuvant therapy are staged before treatment (cStage) and after treatment (ypStage). We aimed to compare the prognostic reliability of cStage and ypStage, alone and in combination. Materials and Methods: Data for all patients who received neoadjuvant therapy followed by surgery for gastric adenocarcinoma from 2004 to 2015 were extracted from the National Cancer Database. Kaplan-Meier (KM)curves were used to model overall survival based on cStage alone, ypStage alone, cStage stratified by ypStage, and ypStage stratified by cStage. P-values were generated to summarize the differences in KM curves. The discriminatory power of survival prediction was examined using Harrell's C-statistics. Results: We included 8,977 patients in the analysis. As expected, increasing cStage and ypStage were associated with worse survival. The discriminatory prognostic power provided by cStage was poor (C-statistic 0.548), while that provided by ypStage was moderate (C-statistic 0.634). Within each cStage, the addition of ypStage information significantly altered the prognosis (P<0.0001 within cStages I-IV). However, for each ypStage, the addition of cStage information generally did not alter the prognosis (P=0.2874, 0.027, 0.061, 0.049, and 0.007 within ypStages 0-IV, respectively). The discriminatory prognostic power provided by the combination of cStage and ypStage was similar to that of ypStage alone (C-statistic 0.636 vs. 0.634). Conclusions: The cStage is unreliable for prognosis, and ypStage is moderately reliable. Combining cStage and ypStage does not improve the discriminatory prognostic power provided by ypStage alone. A ypStage-based prognosis is minimally affected by the initial cStage.

• Journal of Chest Surgery
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• 제54권3호
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• pp.186-190
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• 2021

Background: Pre-lifting of the sternum marked a major turning point in pectus excavatum repair. The author developed the crane technique in 2002 and successfully applied it to more than 2,000 cases using sternal wire stitching. However, blind sternal suturing limited the use of the wire-stitch crane. We propose a novel screw for sternal lifting as a new tool for the crane technique. Methods: We developed a screw system strong enough to withstand the pressure needed for sternum lifting. The screw was designed to have a broader thread to hold the bony tissue securely. The screw's sustaining power was tested using the torsion, driving torque, and axial pull-out tests in a polyurethane block and ex-vivo porcine sternum. Results: The screws were easily driven into the sternum, and the head of the screw was connectable to the table-mounted retractor. In the torsion test, the 2° offset torsional yield was 4.53 N·m (reference value, 1 N·m). In the polyurethane block driving torque test, the maximum torque was 0.98 N·m (reference value, 0.70 N·m). The axial pull-out test was 446 N (reference value, 100 N). The maximum pull-out resistance in the ex-vivo porcine sternum model was 1,516 N. Conclusion: The screw crane was strong enough to sustain the chest wall weight to be lifted. Thus, the screws could effectively replace the sternal wire stitching in crane pre-lifting of the sternum. We expect that application of the screw-crane will be easy and that it will improve the safety and success rate of pectus repair surgery.

• 새물리
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• 제68권11호
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• pp.1262-1267
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• 2018

음의 중력상수를 갖는 아인슈타인-본-인펠트 중력 이론에서 별난 물질(exotic matter)을 도입하지 않고 웜홀을 구성하는 새로운 방법을 소개한다. 기존의 방법과는 대조적으로 웜홀의 목은 메트릭 해가 매끄럽게 접합되는 곳에 위치한다. 따라서 목을 지탱하기 위한 별난 물질을 필요치 않는다. 이러한 웜홀의 안정성을 논의하기 위해 최소결합된 스칼라장의 거동을 고려하였다. 새로운 웜홀 배경에서 스칼라장의 유사정준 모드를 웜홀의 목에서는 순전히 들어가는 선속으로 정의하면 웜홀 해의 안정성은 블랙홀의 안정성을 논의할 때 사용되는 방법과 같이 유사정준 모드로 논의할 수 있다. 섭동방정식의 해석적 해를 구하는 것은 불가능하므로 유사정준 모드를 수치적으로 구하는 방법을 제안한다. 블랙홀의 경우와 근본적인 차이점은 급수전개시 지름성분 방정식의 이차항의 계수가 블랙홀의 경우에는 n = 0부터 전개되지만 웜홀의 경우 n = -1부터 전개된다는 것이다.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1619-1624
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• 2018

Laser ablation may provide a minimally invasive palliative treatment for pancreatic cancer. The aim of the current study was to assess the feasibility of a 532-nm laser equipped with a cylindrical light diffuser for the treatment of pancreatic cancer. Monolayers of BxPC-3 human pancreatic cancer cell were exposed to 532 nm laser light. Power levels of 5 - 7 W were used to uniformly target the entire cell colonies for 60 and 120 seconds. The cells were incubated for 24 hours after treatment and viabilities were determined by using a MTT assay. Laser ablation was performed by using the cylindrical light diffuser on six pancreatic tumor tissues obtained from pancreatic cancer xenograft mouse models, which were exposed to the 532 nm light at 5W or 7W for 10 to 30 seconds. In the in vitro study, the survival rates of the pancreatic cancer cells were reduced by 6.6% to 98.9% after the treatment, and the survival rates were reduced by increasing laser power and/or irradiation time. In the pancreatic tumor tissues, a homogenous circular ablation zone was observed in all tumors and the ablation distance induced by the laser irradiation showed to be constant from the diffuser to all directions (standard deviation, 0.3 - 1.3 mm). Ablation distance and area increased with increasing laser power and/or irradiation time. The 532 nm laser effectively killed pancreatic cancer cells, and the cylindrical light diffuser was found to be suitable for laser ablation as it provided uniform ablation in pancreatic cancer.