• Archives of Plastic Surgery
• /
• v.49 no.1
• /
• pp.91-98
• /
• 2022

Background Predicting the need for post-traumatic reconstruction of lower extremity injuries remains a challenge. Due to the larger volume of cases in adults than in children, the majority of the medical literature has focused on adult lower extremity reconstruction. This study evaluates predictive risk factors associated with the need for free flap reconstruction in pediatric patients following lower extremity trauma. Methods An IRB-approved retrospective chart analysis over a 5-year period (January 1, 2012 to December 31, 2017) was performed, including all pediatric patients (<18 years old) diagnosed with one or more lower extremity wounds. Patient demographics, trauma information, and operative information were reviewed. The statistical analysis consisted of univariate and multivariate regression models to identify predictor variables associated with free flap reconstruction. Results In total, 1,821 patients were identified who fit our search criteria, of whom 41 patients (2.25%) required free flap reconstruction, 65 patients (3.57%) required local flap reconstruction, and 19 patients (1.04%) required skin graft reconstruction. We determined that older age (odds ratio [OR], 1.134; P =0.002), all-terrain vehicle accidents (OR, 6.698; P<0.001), and trauma team activation (OR, 2.443; P=0.034) were associated with the need for free flap reconstruction following lower extremity trauma in our pediatric population. Conclusions Our study demonstrates a higher likelihood of free flap reconstruction in older pediatric patients, those involved in all-terrain vehicle accidents, and cases involving activation of the trauma team. This information can be implemented to help develop an early risk calculator that defines the need for complex lower extremity reconstruction in the pediatric population.

• Genomics & Informatics
• /
• v.15 no.1
• /
• pp.2-10
• /
• 2017

Early detection and proper management of kidney rejection are crucial for the long-term health of a transplant recipient. Recipients are normally monitored by serum creatinine measurement and sometimes with graft biopsies. Donor-derived cell-free deoxyribonucleic acid (cfDNA) in the recipient's plasma and/or urine may be a better indicator of acute rejection. We evaluated digital PCR (dPCR) as a system for monitoring graft status using single nucleotide polymorphism (SNP)-based detection of donor DNA in plasma or urine. We compared the detection abilities of the QX200, RainDrop, and QuantStudio 3D dPCR systems. The QX200 was the most accurate and sensitive. Plasma and/or urine samples were isolated from 34 kidney recipients at multiple time points after transplantation, and analyzed by dPCR using the QX200. We found that donor DNA was almost undetectable in plasma DNA samples, whereas a high percentage of donor DNA was measured in urine DNA samples, indicating that urine is a good source of cfDNA for patient monitoring. We found that at least 24% of the highly polymorphic SNPs used to identify individuals could also identify donor cfDNA in transplant patient samples. Our results further showed that autosomal, sex-specific, and mitochondrial SNPs were suitable markers for identifying donor cfDNA. Finally, we found that donor-derived cfDNA measurement by dPCR was not sufficient to predict a patient's clinical condition. Our results indicate that donor-derived cfDNA is not an accurate predictor of kidney status in kidney transplant patients.

• Archives of Plastic Surgery
• /
• v.33 no.6
• /
• pp.784-788
• /
• 2006

Purpose: For the reconstruction of the ankle joint as well as the soft tissue defect in the distal lower leg, a free flap or a local flap has been used, and because of the condition of patients, if a complex microvascular surgery under general anesthesia could not be performed, it could be reconstructed by using the distally based lateral supramalleolar fascio-cutaneous island flap using the perforating branch of the peroneal artery in the ankle area. Methods: The study subjects were 4 male patients between 53 years and 73 years of age. 2 cases were tissue defect in the medial malleolus area due to systemic diseases such as gouty arthritis accompanied traffic accident, diabetes mellitus foot, atherosclerotic obliterans, etc., 1 case was the defect in the pretibia area, and 1 case was the defect underneath the lateral malleolus, which was reconstructed by the distally based lateral supramalleolar fascio-cutaneous island flap. The donor area was the skin harvested from the groin, and the full thickness skin graft was performed. The size of the flap varied from $4{\times}3cm$ to $9{\times}6cm$. As the flap border, the medial side was to the tibialis anterior tendon, the lateral side was to the fibula crest, and the proximal area was less than the fibula size. Results: The consequence is that, in total 4 cases, the congestion in the flap began from 12 hours after the surgery, and the progression of congestion was ceased on the 5th day after the surgery, and finally epidermal bulla and sloughing, partial necrosis was developed. After the end of necrosis, the defect area was reconstructed successfully by the second full thickness skin graft. Conclusions: Although the distally based lateral supramalleolar fascio-cutaneous island flap has the shortcoming of requiring the second skin graft, it has the advantages that it does not require a long complex microsurgery, the flap itself is thin, it is similar to the color of the skin in the recipient area, and it does not leave a big scar in the donor area. Therefore, it is thought that for the cases who could not undergo a long complex surgery due to systemic diseases or the cases of patients whose condition of the recipient area is not suitable for microsurgery, the lateral supramalleolar fascio-cutaneous island flap is very useful for the reconstruction of the distal lower leg and the ankle joint area.

• Journal of Chest Surgery
• /
• v.37 no.6
• /
• pp.474-481
• /
• 2004

Background: Tracheal transplantation is necessary in patients with extensive tracheal stenosis, congenital lesions and other oncologic conditions but bears. many critical problems compared to other organ transplantations. The purpose of this study was to develop intestine-cartilage composite grafts for potential application in tracheal reconstruction by free intestinal graft. Material and Method: Hyaline cartilage was harvested from trachea of 2 weeks old New Zealand White Rabbits. Chondrocytes were isolated and cultured for 8 weeks. Cultured chondrocytes were seeded in the PLGA scaffolds and mixed in pluronic gel Chondrocyte bearing scaffolds and gel mixture were embedded in submucosal area of stomach and colon of 3 kg weighted New Zealand White Rabbits under general anesthesia. 10 weeks after implantation, bowels were harvested for evaluation. Result: We identified implantation site by gross examination and palpation. Developed cartilage made a good frame for shape memory. Microscopic examinations included special stain s howed absorption of scaffold and cartilage formation even though it was not fully matured. Conclusion: Intestine-cartilage composite graft could be applicable in the future as tracheal substitute and should be further investigated.

• Journal of the Korean Arthroscopy Society
• /
• v.3 no.1
• /
• pp.40-43
• /
• 1999

Arthroscopic anterior cruciate ligament(ACL) reconstruction using four-strand hamstring tendon with looping around transfixing screw in femoral tunnel requires osteointegration between the grafted tendon and bone for stability of the knee. Authors have experienced a histologic finding of osteointegration between the grafted autogenous hamstring tendon and bone in femoral tunnel after arthroscopic ACL reconstruction. A patient received arthroscopic ACL reconstruction with autogenous four strand hamstring tendon for the ACL injury. Traumatic re-rupture of mid-substance of ACL graft was developed at thirteenth week after operation. During the procedures of arthroscopic revision at fifteenth week after initial ACL reconstruction, biopsy was performed at the site of interface between grafted tendon and bone in femoral tunnel. Integration between the grafted tendon and bone was evident by demonstrating the continuity of collagen fiber between bond and tendon. This histologic finding and the low incidence of early graft failure suggest that free tendon autograft attached to bone by looping around a transfixing screw in femoral tunnel undergoes adequate osteointegration between 12 and 15 weeks after surgery and authors thought that insertion of bone chip into the femoral tunnel would accelerate osteointegration procedure.

• Clinical and Experimental Pediatrics
• /
• v.56 no.11
• /
• pp.490-495
• /
• 2013

Purpose: The use of cyclosporine and mini-dose methotrexate (MTX) is a common strategy for graftversus- host disease (GVHD) prophylaxis in allogeneic transplants. We investigated whether patients who receive fewer than the planned MTX doses are at increased risk for GVHD. Methods: The study cohort included 103 patients who received allogeneic transplants at the Department of Pediatrics of The Catholic University of Korea College of Medicine, from January 2010 to December 2011. MTX was administered on days 1, 3, 6, and 11 after transplant at a dose of 5 $mg/m^2$ each. Within the cohort, 76 patients (74%) received all 4 doses of MTX [MTX(4) group], while 27 patients (26%) received 0-3 doses [MTX(0-3) group]. Results: Although there was no difference in neutrophil engraftment between the 2 groups, platelet engraftment was significantly faster in the MTX(4) group (median, 15 days), compared to the MTX(0- 3) group (median, 25 days; P =0.034). The incidence of grades II-IV acute GVHD was not different between the MTX(4) and MTX(0-3) groups (P =0.417). In the multivariate study, human leukocyte antigen mismatch was the most significant factor causing grades II-IV acute GVHD (P =0.002), followed by female donor to male recipient transplant (P =0.034). No difference was found between the MTX(4) and MTX (0-3) groups regarding grades III-IV acute GVHD, chronic GVHD, and disease-free survival. Conclusion: Our results indicate that deviations from the full dose schedule of MTX for GVHD prophylaxis do not lead to increased incidence of either acute or chronic GVHD.

• Applied Chemistry for Engineering
• /
• v.21 no.3
• /
• pp.343-348
• /
• 2010

The surface of low density polyethylene (LDPE) film was oxyfluorinated under different reaction conditions to introduce hydroperoxide groups and change surface characteristics. Hydroperoxide functional groups created by oxyfluorination were used as active sites for graft polymerization with hydrophobic monomer, acryl amide (AM), and hydrophilic monomer, methyl methacrylate (MMA) to carry out the second modification of the LDPE film surface. The surface properties of the OFPE films and grafted OFPE films were characterized by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, ATR-IR, contact angle measurement and DSC. From the results of DPPH method, the amount of hydroperoxide groups on the oxyfluorinated LDPE film continuously increased as the total pressure in the oxyfluorination and the partial pressure of fluorine gas increased. The water contact angle and surface free energy measurements showed that hydrophilic liquid (water) contact angle on LDPE film surface decreased with hydrophilic AM grafting and hydrophobic liquid (methylene diiodide) contact angle on LDPE film surface decreased with hydrophobic MMA grafting. These were attributed to AM or MMA monomer grafting and the wettability of LDPE filmsurface to hydrophilic and hydrophobic liquids were improved.

• Membrane Journal
• /
• v.29 no.1
• /
• pp.44-50
• /
• 2019

In this paper, we developed mixed matrix membranes (MMMs) consisting of SBS-g-POEM block-graft copolymer, ionic liquid (EMIMTFSI) and ZIF-8 nanoparticles to separate a $CO_2/N_2$ gas pair. The SBS-g-POEM is a rubbery block-graft copolymer synthesized through low-cost free-radical polymerization. The EMIMTFSI was dissolved into the SBS-g-POEM matrix and solution synthesized ZIF-8 nanoparticles were also dispersed into the copolymer matrix. The physico-chemical properties of manufactured membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), which showed that the components were compatible with each other. The gas separation performance was confirmed by time-lag measurements showing $CO_2$ permeability of 537.0 barrer and $CO_2/N_2$ selectivity of 15.2. The result represents the EMIMTFSI and ZIF-8 nanoparticles improves the gas permeability more than two-times, without significantly sacrificing the $CO_2/N_2$ selectivity.

• Journal of Chest Surgery
• /
• v.37 no.11
• /
• pp.897-902
• /
• 2004

Background: Although great concerns have been raised regarding the suitability of the use of the radial artery as a bypass conduit after transradial catheterization, there has been no studies that examined this issue in Korea. The purpose of this study was to compare clinical and angiographic results of radial artery grafting between patients with and without previous transradial catheterization. Material and Method: From January 2000 to February 2004, a total of 93 patients underwent coronary artery bypass grafting using the radial artery: 49 patients received preoperative transradial catheterization for coronary angiography (group I) and 44 patients did not (group II). These patients were retrospectively reviewed. Result: There was no significant difference in sex ratio, age, clinical diagnosis, risk factors, ejection fraction and early clinical outcomes between two groups. The graft patency rates in groups I and II were both 100% in the internal thoracic artery and in the radial artery, and 85% and 86% in the saphenous vein. respectively. The stenosis-free graft patency in groups I and II were 93% and 81% in the radial artery respectively but no statistical significance was shown. Conclusion: There was no significant difference in graft patency at postoperative coronary angiography between two groups. Radial artery graft after transradial catherization seems to be suitable for bypass conduit in short-term analysis.

• Journal of Korean Foot and Ankle Society
• /
• v.1 no.1
• /
• pp.59-64
• /
• 1997

The aims of free tissue transplantation to the injured foot are to cover the exposed blood vessels, nerves, muscles, tendons and bones, to clear up infection, to lessen the morbidity, to shorten the hospitalization, and to prepare for further surgical procedures when no local or transpositioning flaps are available. Authors have carried out free flap transplantation in 13 cases of crushing injury, osteomyelitis and electrical burn in the foot at Chonbuk National University Hospital from June 1992 through May 1996. The results were as follows : 1. 9 cases of 13 (69%) were sustained from the traffic accident. 2. The dorsalis pedis free flap transplantation has been performed most frequently in 5 cases (38.5%), followed gracilis muscle flap in 4 cases(30.7%), rectus abdominis muscle flap in 2 cases(15.4%), latissimus dorsi muscle flap and upper arm flap in 1 each. 3. 6 muscle flaps were covered with split thickness skin graft 20 days after microsurgical anastomosis. 4. All of 13 cases were survived after microsurgical procedure and showed excellent coverage in the foot.