• Archives of Plastic Surgery
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• v.34 no.4
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• pp.432-435
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• 2007

Purpose: The jejunal free flap has the shorter ischemic time than other flap and requires a laparotomy to harvest it. As the evaluation of the perfusion the buried flap is very important, the perfusion of the buried jejunal free flap requires monitoring for its salvage. We tried to improve the monitoring flap method in the jejunal free flap and examined its usefulness. Methods: From March 2002 to March 2006, the monitoring flap method was applied to 4 cases in 8 jejunal free flaps for the pharyngeal and cervical esophageal reconstructions. The distal part of the jejunal flap was exposed without suture fixation through cervical wound for monitoring its perfusion. The status of perfusion was judged by the color change of jejunal mucosa and mesentery. If necessary, pin prick test was performed. Doppler sonography was applied to mesenteric pedicle of the monitoring flap in case of suspicious abnormal circulation. Results: The monitoring flap shows no change in 3 cases, but the congestion happened in one case at the 12 hours after the operation. This congestion was caused by the twisting or kinking of the mesenteric pedicle of the monitoring flap. So, we fixed up the monitoring flap close to adjacent cervical skin for prevention of rotation. Finally, the main part of transferred jejunal flap was intact. Conclusion: The success of a jejunal free flap depends on close postoperative monitoring and early detection of vascular compromise. So, various monitoring methods have been tried, for instance, direct visualization using a fiberoptic pharyngoscope, through a Silastic window placed in the neck flap, or external surface monitoring with an Doppler sonography, use of a buried monitoring probe. But, all of the above have their own shortcomings of simplicity, non-invasiveness, reliability and etc. In our experience, monitoring flap can be a accurate and reliable method.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.82-85
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• 2004

Flap monitoring is important for flap salvage. Although there are many methods to observe the flap, practical methods mostly used are subjective methods. Recording flap surface temperature is one of the objective methods of flap monitoring. We used an infra-red thermometer to simplify monitoring of the flap temperature. 60 groin flaps of SD rats are used in the experiment. Artificial arterial or venous insufficiency was made and the surface temperature was checked and compared with body temperature. In the results, the temperature of the arterial clamped flaps was lower than that of body and the mean difference was $0.3^{\circ}C$ after 20 minutes of clamping. In the vein-clamped flaps, the mean decrease was $0.4^{\circ}C$ after 30 minutes of clamping. The all difference of the temperature between the flaps and body was statistically significant. Our results suggest that flap monitoring by infra-red thermometer is simple, useful and helpful to evaluate the flap status.

• Archives of Reconstructive Microsurgery
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• v.21 no.1
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• pp.14-20
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• 2012

Purpose: Defect after ablation of hypopharyngeal cancer often requires reconstruction by free tissue transfer. Since neo-hypopharynx is totally buried, various methods have been suggested for monitoring. We propose a modified design of anterolateral thigh (ALT) free flap for reconstruction of pharyngolaryngectomy defect, which has an exteriorized part for clinical monitoring and allows for primary closure. Materials and Methods: Three consecutive patients with hypopharyngeal cancer were reconstructed with ALT flap with modified design: 1) distal part of flap was elongated into fusiform shape and used as exteriorized monitoring segment with a deepithelized bridge and 2) proximal part was designed as curve so the maximum width of the flap was reduced to less than 10 cm. Results: Patient 1, 2 had uneventful postoperative course with healthy skin color and fresh pin prick bleeding. In patient 3, defect after cancer ablation was shorter than usual and deepithelized bridge was longer. When the general hemodynamic status of the patient was aggravated in postoperative course, the color of monitoring skin was changed. Viability of the whole flap was confirmed by endoscopy. However, leakage developed after 3 weeks and repair was necessary. In all patients the donor sites were closed primarily. Conclusion: By the modified design of ALT flap, clinical monitoring can be possible by examining exteriorized monitoring flap and also donor site can be closed primarily. However possibility of false positive exists and technical caution and patient selection is needed because of danger of leakage.

• 대한미세수술학회:학술대회논문집
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• 1997.10a
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• pp.137-137
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• 1997

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.6
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• pp.464-470
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• 2018

In this paper, a practical method of estimating the flap hinge moments which change according to the aircraft flap operations was introduced. For the flap design, the hinge moment derived by structural load analysis and wind tunnel tests was able to be compared with the real flight hinge moment, and the static safety of the flap structure could be verified though this comparison. In order to perform the tests, two strain gauges were installed on the flap hinge and an onboard device for aircraft load monitoring was utilized. Through the ground test, the correlation between the strain and the moment of the flap hinge was calibrated with analytic and finite element analysis. During the flight test, strain signals together with the flap deflection angles and airspeed were recorded. Finally, the flight hinge moments could be predicted by the measured strain which was calibrated with the analytic and the finite element analysis.

• 대한두경부종양학회:학술대회논문집
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• 2001.11a
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• pp.276-276
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• 2001

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.70-79
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• 1996

From January 1980 to May 1995, ninety-six patients had been treated by free-flap transfer for the soft tissue defects of the extremities. Ninety-eight cases of free-tissue transfer were reviewed to evaluate the clinical reliability in terms of survival and quality of long-time function after reconstructive surgery. Among these 98 cases(27 cases in latissimus dorsi myocutaneous flap, 25 in dorsalis pedis flap, 20 in forearm fasciocutaneous flap, 9 in groin flap, 7 in gracilis myocutaneous flap, 6 in 1st web space flap of foot and 4 cases in tensor fascia lata flap), 92 cases of then were survived. 7 cases were performed with vein grafts. We ananalyzed the reconstruction of the extremities on 98 cases with the soft tissue defects which had been reconstructed free-flap transfer and followed for minimum 1 year period at Korea University Hospital. 1. 92 cases(93.9%) of the total 98 cases were successful and can be obtained the excellent results in soft tissue free-flap transfer. 2. While there were no clinically significant differences in survival rate of flaps transferred from different potential flap donor sites,3 cases of 9 groin flaps were showed higher failure rate due to the complications such as arterial thrombosis, infection and anatomical variation of vessels. 3. Postoperative thrombectomy was performed in 30 cases to be occured in the arterial and venous thrombosis. The revision was failed in 2 cases due to persistent arterial thrombosis and infection, then treated with skin graft. 4. Vein graft was frequently required in severely compromised-soft tissue defects resulted from high-energy trauma. The vein graft was not stitistically significant on the frequency of flap failure rate(P<0.04). 5. Meticulous monitoring, careful planning, early revision and technical considerations will provide for a high clinical success of the free-flap transfer.

• Archives of Plastic Surgery
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• v.45 no.1
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• pp.45-50
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• 2018

Background Free muscle flaps are a mainstay for reconstruction of distal third leg wounds and for large lower extremity wounds with exposed bone. However a major problem is the significant postoperative flap swelling, which may take months to resolve. We studied the efficacy and safety of immediate application of a vacuum assisted closure (VAC) dressing after a free muscle flap to the lower extremity. Methods Over a 19 months period, all consecutive free muscle flaps for lower extremity reconstruction at a Level I trauma center were evaluated prospectively for postoperative flap thickness, complications and flap survival. Immediate application of a VAC dressing was performed in 9 patients, while the flap was left exposed for monitoring in 8 patients. Results There was no statistically significant difference in flap survival between both cohorts. Mean flap thickness at postoperative day 5 for the VAC group was $6.4{\pm}6.4mm$, while flap thickness for the exposed flap group was $29.6{\pm}13.5mm$. Flap thickness was significantly decreased at postoperative day 5 for the VAC dressing group. Conclusions Immediate application of VAC dressing following free muscle flaps to the lower extremity does not compromise flap survival or outcomes and results in decreased flap thickness and a better aesthetic outcome.

• Archives of Craniofacial Surgery
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• v.15 no.3
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• pp.121-124
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• 2014

The use of the implantable Doppler device eases the burden of free flap monitoring, and allows caregivers to notify healthcare personnel of a potential vascular event. A 24-year-old female patient underwent anterolateral thigh adipofascial flap surgery to provide a buried flap on the left temporal area for a depressed and infected skull wound. The author was able to salvage the flap from two venous occlusions, which was made possible by early notifications from the caregiver who reported changes in the Doppler signal.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.457-461
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• 2021

Background Pedicled perforator flaps can present postoperative complications similar to those encountered in free flap surgery. Beyond a clinical evaluation, there is still no reliable technical aid for the early prediction of vascular issues. The aim of this study was to assess the support of near-infrared spectroscopy technology as an intraoperative tool to anticipate postsurgical flap ischemia. Methods We prospectively enrolled 13 consecutive patients who were referred to our hospital from March 2017 to July 2018 and required a reconstructive procedure with a pedicled fasciocutaneous perforator flap. We measured flap peripheral capillary oxygen saturation (SpO₂) in each patient with a Somanetics INVOS 5100C Cerebral/Somatic Oximeter (Medtronic), both before and after transposition. Patient demographics, operative data, and complications were then recorded during the following 6 months. We analyzed the data using the Wilcoxon signed-rank test and linear regression. Results The mean flap SpO₂ before and after transposition was 92%±3% and 78%±19%, respectively. The mean change in SpO₂ was 14%±17%, with a range of 0% to 55%. The change in saturation and mean saturation ratio were significantly different between patients with and without postoperative flap necrosis. Conclusions An immediate quantitative analysis of flap peripheral capillary SpO₂ after transposition has never before been described. In our experience, an intraoperative drop in SpO₂ equal to or greater than 15%-20% predicted vascular complications in pedicled perforator flaps. Conversely, flap size and rotation angle were not correlated with the risk of flap necrosis.