• Korean Journal of Head & Neck Oncology
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• v.16 no.1
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• pp.26-32
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• 2000

Background and Objectives: Various flaps are using for reconstruction of hypopharyngeal and esophageal defect. However, complication and indication of each flap are not fully analyzed. Patient and Methods: Records of 52 hypopharyngeal cancer patients who had surgical treatment and 13 other head and neck cancer patients who underwent hypopharyngeal and/or esophageal reconstruction with flap were retrospectively analyzed. Eighty three percent(54 cases) of patients needed reconstruction other than primary pharyngeal closure. Five split thickness skin graft, 1 pectoralis major myocutaneous flap, 20 forearm free flap, 13 jejunal free flap, 15 gastric pull up were used. Result: Flap failure was noted in 2 cases who had subsequent gastric transposition. Wound dehiscence and fistula were most common problem of forearm free flap. Most fistulas were developed in patients with conduit type reconstruction of forearm flap while there wasn't any fistula in patient with patch type reconstruction. Stenosis of lower anastomosis was the frequent problem of jejunal transfer. Gastric pull-up has frequent com-plication of stomal stenosis. All but three patients had reached oral feeding postoperatively. Conclusion: Based on this study, forearm flap is effective in partial hypopharyngeal defect while jejunum is the choice for circumferential defect. Gastric pull-up is for combined esophageal defect.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.181-186
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• 2013

Background Partial or complete necrosis of a skin flap is a common problem. Polydeoxyribonucleotide (PDRN) can be extracted from trout sperm and used as a tissue repair agent. The aim of this study was to investigate whether PDRN could improve the survival of random pattern skin flaps in rats. Methods Twenty-two male Sprague-Dawley rats were randomly divided into two groups: the PDRN treatment group (n=11) and the control group (n=11). Caudally pedicled random pattern skin flaps were elevated on their dorsal skin and resutured. The treatment group received daily intraperitoneal administration of PDRN (8 mg/kg/day), and the control group received fluid vehicle (NaCl 0.9%, 8 mg/kg/day) from day 0 to day 6. On day 7, the flap survival was evaluated and the harvested tissue surrounding the demarcation line of the necrotic area was stained with H&E, anti-rat vascular endothelial cell growth factor (VEGF) antibody, and PECAM-1/CD31 antibody. Results The average necrotic area of the flap in the PDRN group was significantly smaller when compared with that of the control group. Histologic and immunohistochemical evaluation showed that granulation thickness score and VEGF-positive staining cells were marked higher in the PDRN group than in the control group. PECAM-1/CD31-positive microvascular densities were significantly higher in the PDRN group when compared with the control group. Conclusions This study confirms that PDRN improves the survival of random pattern skin flaps in rats. These results may represent a new therapeutic approach to enhancing flap viability and achieving faster wound repair.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.24-25
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• 2006

SmBCO coated conductors were successfully fabricated using EDDC (Evaporation using Drum in Dual Chambers) deposition system that is a bath type co-evaporation system for fabrication of superconducting tape and divided into two chambers named evaporation chamber and reaction chamber. To obtain long and high quality superconducting coated conductor, it is very important to secure the uniformity of all the deposition parameters m the deposition system such as deposition temperature, oxygen partial pressure, compositional ratios and so on. Therefore, we investigated the distribution of the parameters along the axis of the drum m EDDC on which tapes were wound helically. When the temperature on the middle point of deposition zone was $700^{\circ}C$, that on the edge of deposition zone was $675^{\circ}C$. When the thickness of SmBCO layer on the middle point of deposition zone was 1063 nm, that on the edge of deposition zone was 899 nm. The partial pressure of oxygen was 5 mTorr in the reaction chamber while that was $7{\times}10^{-5}$Torr in the evaporation chamber. The composition ratio of Sm:Ba:Cu, that was measured by EDX, was very uniform along the axis of the drum. Under these deposition conditions, critical current distribution along the drum axis was 175 A/cm, 190A/cm, 217.5 A/cm, 182.5 A/cm, 175 A/cm with the interval of 9 cm between samples. It means that the EDDC system has the potential of fabricating (100m, 200A) class coated conductor.

• Archives of Reconstructive Microsurgery
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• v.15 no.2
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• pp.92-100
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• 2006

Radial forearm free flap (RFFF) has been established itself as a versatile and widely used method for reconstruction of the head and neck, although it is still criticized for high mortality of donor site. Delayed wound healing, cosmetic deformity, vascular compromise and potentially reduced wrist function have many plastic surgeons hesitate to adapt it as a first choice in micro-reconstruction. To overcome these drawbacks, some techniques for donor-site repair such as V-Y advancement with full thickness skin graft (FTSG), application of artificial dermis ($Terudermis^{(R)}$) or acellular dermal matrix ($AlloDerm^{(R)}$), and double-opposing rhomboid transposition flap have been reported. Authors performed 4 cases of RFFF in old-aged patients of the head and neck cancer from April 2005 to February 2006. We compared the outcomes of donor site of RFFF which were resurfaced with split thickness skin graft (STSG) only and STSG overlying an $AlloDerm^{(R)}$. Patients were all males ranging from 59 to 74 years old (mean, 67.5). Three of them had tongue cancers, and the other showed hypopharyngeal cancer. All cases were pathologically confirmed as squamous cell carcinomas. We included the deep fascia into the flap, so called subfascially elevated RFFF in three cases, and in the other one, we dissected the RFFF suprafascially leaving the fascia intact. The donor site of the suprafascially elevated RFFF was resurfaced with STSG only. Among three of subfascially elevated RFFFs, donor-sites were covered with thin STSG only in one case, and STSG overlying $AlloDerm^{(R)}$ in two cases. All RFFFs were survived completely without any complication. The donor site of the suprafascially elevated RFFF was taken well with STSG only. But, the partial graft loss exposing brachioradialis and flexor carpi radialis muscle was unavoidable in all the subfascially elevated RFFFs irregardless of $AlloDerm^{(R)}$ application. Considering that many patients of the head and neck cancer are in old ages, we believe the RFFF is still a useful and versatile choice for resurfacing the head and neck region after cancer ablation. Its reliability and functional characteristics could override its criticism for donor site in old-aged cancer patients.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.521-526
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• 2008

Purpose: Most burn scar contractures are curable with skin grafts, but free flaps may be needed in some cases. Due to the adjacent tissue scarring, local flap is rarely used, and thus we may consider free flap which gives us more options than local flap. However, inappropriate performance of free flap may lead to unsatisfactory results despite technical complexity and enormous amount of effort. The author will discuss the points we should consider when using free flaps in treating burn scar contractures Methods: We surveyed patients who underwent free flaps to correct burn scar contractures from 2000 to 2007. We divided patients into two groups. The first group was those in which free flaps were inevitable due to exposure of deep structures such as bones and tendons. The second group was those in which free flap was used to minimize scar contracture and to achieve aesthetic result. Results: We performed 44 free flap on 42 patients. All of the flaps were taken well except one case of partial necrosis and wound dehiscence. Forearm free flap was the most common with 21 cases. Most of the cases(28 cases) in which free flaps were inevitable were on the wrist and lower limbs. These were cases of soft tissue defect due to wide and extensive burns. Free flaps were done in 16 cases to minimize scar contracture and to obtain aesthetic outcome, recipient sites were mostly face and upper extremities. Conclusion: When using free flaps for correction of burn scar contractures, proper release and full resurfacing of the contracture should be carried out in advance. If inadequate free flap is performed, secondary correction is more challenging than in skin grafts. In order to optimize the result of reconstruction, flap thickness, size and scar of the recipient site should be considered, then we can achieve natural shape, and minimize additional correction.