• Archives of Craniofacial Surgery
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• v.20 no.5
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• pp.304-309
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• 2019

Background: Treatment for venous malformations of the head and neck includes sclerotherapy, surgical resection, or a combination of both. Surgical resection can remove or reduce the volume of vascular lesions; however, surgery can cause postoperative scarring and potential surgical complications. This study sought to determine the effectiveness of surgery for the treatment of venous malformations of the head and neck. Methods: A retrospective review of the medical records of patients who received surgeries for venous malformations of the head and neck from January 2011 to July 2019 was performed. Using clinical photographs, preoperative and postoperative Doppler ultrasonography, outpatient clinic records, and operation records, the postoperative result and complications were evaluated for each case. Results: Among patients who visited our vascular anomalies clinic, 43 patients (ratio of male to female= 24:19) received surgeries for venous malformations of the head and neck. Twenty-nine patients had undergone surgery only, five patients received sclerotherapy after surgery, and nine patients received surgery after preoperative sclerotherapy. In postoperative evaluations, the result was excellent in 24 patients, good in 18 patients, and poor in one patient. Four patients experienced a recurrence of lesions with lagophthalmos, drooping of the corner of the mouth, partial wound necrosis, and scar widening found in one patient each. Conclusion: Because the head and neck region is the most exposed area in the body, more active implementation of surgical treatments with or without sclerotherapy is essential to reduce the functional and cosmetic impairments associated with venous malformations.

• Archives of Plastic Surgery
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• v.48 no.2
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• pp.219-223
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• 2021

Background A micro-arteriovenous fistula (AVF) is a minute, short shunt between an artery and a vein that does not pass through a capillary. We investigated the association between micro-AVFs and lymphedema using computed tomography angiography (CTA) and venous blood gas analysis. Methods In 95 patients with lower limb lymphedema, the presence or absence of early venous return (EVR) was compared between patients with primary and secondary lymphedema. Furthermore, we investigated the difference in the timing of edema onset in patients with secondary lymphedema with or without EVR using CTA. In 20 patients with lower limb lymphedema with confirmed early EVR in a unilateral lower limb, the partial pressure of oxygen (PO₂) was compared between the lower limb with EVR and the contralateral lower limb. Results Secondary lymphedema with or without EVR occurred at an average of 36.0±59.3 months and 93.5±136.1 months, respectively; however, no significant difference was noted. PO₂ was 57.6±11.7 mmHg and 44.1±16.4 mmHg in the EVR and non-EVR limbs, respectively, which was a significant difference (P=0.005). Conclusions EVR and venous blood gas analysis suggested the presence of micro-AVFs in patients with lower extremity edema. Further research is warranted to examine the cause of micro-AVFs, to advance technology to facilitate the confirmation of micro-AVFs by angiography, and to improve lymphedema by ligation of micro-AVFs.

• Archives of Plastic Surgery
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• v.49 no.2
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• pp.227-239
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• 2022

Complications experienced during lymphatic surgery have not been ubiquitously reported, and little has been described regarding how to prevent them. We present a review of complications reported during the surgical management of lymphedema and our experience with technical considerations to reduce morbidity from lymphatic surgery. A comprehensive search across different databases was conducted through November 2020. Based on the complications identified, we discussed the best approach for reducing the incidence of complications during lymphatic surgery based on our experience. The most common complications reported following lymphovenous anastomosis were re-exploration of the anastomosis, venous reflux, and surgical site infection. The most common complications using groin vascularized lymph node transfer (VLNT), submental VLNT, lateral thoracic VLNT, and supraclavicular VLNT included delayed wound healing, seroma and hematoma formation, lymphatic fluid leakage, iatrogenic lymphedema, soft-tissue infection, venous congestion, marginal nerve pseudoparalysis, and partial flap loss. Regarding intra-abdominal lymph node flaps, incisional hernia, hematoma, lymphatic fluid leakage, and postoperative ileus were commonly reported. Following suction-assisted lipectomy, significant blood loss and transient paresthesia were frequently reported. The reported complications of excisional procedures included soft-tissue infections, seroma and hematoma formation, skin-graft loss, significant blood loss, and minor skin flap necrosis. Evidently, lymphedema continues to represent a challenging condition; however, thorough patient selection, compliance with physiotherapy, and an experienced surgeon with adequate understanding of the lymphatic system can help maximize the safety of lymphatic surgery.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.417-426
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• 2021

Background Soft tissue coverage plays a vital role in replacing the vascularity of the underlying bone in Gustilo type IIIB fractures. The aim of this article was to evaluate the feasibility of local pedicled flaps in type IIIB fractures at a tertiary care center. Methods We included all cases of open Gustilo-Anderson type IIIB fractures of the tibia treated with local flap coverage from January 2017 to February 2019. We carried out a retrospective analysis to investigate the relationships of complications, hospital stay, and cost-effectiveness with the choice of flap, infective foci, site and size of the defect, and type of fixation. Results Out of 138 Gustilo type IIIB fractures analyzed in our study, 27 cases had complications, of which 19 (13.76%) involved flap necrosis, four (2.89%) were infections, three (2.17%) involved partial necrosis, and one (0.72%) was related to bone spur development. Flap complications showed a statistically significant association with the perforator flap category (propeller flaps in particular) (P=0.001). Flap necrosis showed a significant positive correlation with cases treated within 3 weeks after trauma (P=0.046). A significant positive correlation was also found between defect size and the duration of hospital stay (P=0.03). Conclusions Although local flaps are harvested from the same leg that underwent trauma, their success rate is at least as high as microvascular flaps as reported from other centers. Amidst the local flaps, complications were predominantly associated with perforator flaps.

• Archives of Craniofacial Surgery
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• v.24 no.4
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• pp.189-192
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• 2023

An intraosseous hemangioma of the frontal bone is typically removed via a coronal incision. This procedure, while effective, can be lengthy and may result in complications such as a prominent scar and hair loss. An alternative approach involves a direct incision in the forehead, which leaves a less noticeable scar and allows a quicker recovery. However, in this specific case, the patient declined both coronal surgery and surgery through a direct forehead incision due to cosmetic concerns. Therefore, we proposed an anterior hairline incision. A 35-year-old woman presented with a firm, non-mobile, palpable mass on her right forehead. Preoperative non-contrast computed tomography revealed a heterogeneous osteolytic lesion. We performed an excisional biopsy through the anterior hairline. Postoperative non-contrast computed tomography was conducted 2 and 6 months after surgery. The wound was clean and free of complications, and there was no local recurrence. Partial resection can reduce scarring for patients who are concerned about cosmetic outcomes. However, the potential for recurrence remains a significant concern. We present this case of an anterior hairline incision for a hemangioma located in the forehead, evaluated using serial computed tomography for both preoperative and postoperative imaging.

• Archives of Craniofacial Surgery
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• v.10 no.1
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• pp.49-54
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• 2009

Purpose: Inevitably, Maxillary structural defect follows maxillary cancer extirpation. Maxillary reconstruction is over every surgeon's head. Every physician tried to overcome limited donor site of craniofacial defect. We considered to suggest optimal method of inferior orbital wall defect in functional point as well as esthetic point. Methods: We performed wide excision of maxilla and vascularized partial thickness calvarial bone flap to reconstruct the defect from cancer extirpation in three cases. We select ipsilateral superficial temporal artery, vein and outer cortex of parietal bone flap as donor. And we applied bone flap as inferior orbital wall structure. The bony surface was wrapped with fascia to prevent direct contact between orbital contents and rough bony flap surface. Computed tomography image was checked during follolw up period. Results: We can observe these patients for over two years. In all three cases, We can get fair inferior orbital wall structure. Even though they got radiation therapy, there was no limitation of extraocular movements, no diplopia. no enophthalmos. Also there was minimal donor site morbidity. Conclusion: We suggest vascularized calvarial bone flap is practically excellent strategy for inferior orbital wall reconstruction.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.1
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• pp.25-42
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• 1992

The purpose of this study was to analyze the magnitude and distribution of stress using a photoelastic model from a unilateral distal extention removable partial dentures with five kinds of the direct retainers, that is, the bilaterally designed bar clasp of the cross-arch lingual bar and the unilaterally designed bar clasp, circumferential clasp, mini-Dalbo attachment, and telescope retainer. A photoelastic model for mandible was made of the epoxy resin(PL-1) and hardner (PLH-1) with the acrylic resin teeth used and was coated with plastic cement-1 at the lingual surface of the model, and then five kinds of removable partial dentures were set, A unilateral vertical load of about 16Kg was applied on the first molar and the stress pattern of the photoelastic model under each condition was analyzed by the reflective circular polariscope. The following results were obtained: 1. The conventional removable partial denture with the bilaterally cross arch lingual bar produced the most favorable stress distribution on the residual ridge and supporting structure of abutment teeth than the unilaterally designed removable partial dentures. 2. The unilaterally designed removable partial denture with the bar clasp produced the stress distribution on the residual ridge, except sligtly higher stress concentration on the supporting structure of the abutment teeth, similar to the conventional removable partial denture with the bilaterally designed cross arch lingual bar. 3. On the unilaterally designed removable partial dentures, the bar clasp produced greater stress distribution on the residual ridge and supporting structure of the abutment teeth than the circumferential clasp. 4. On the unilaterally designed removable partial dentures, the mimi-Dalbo attachment produced relatively higher stress concentration on the residual ridge, but produced lesser stress concentration on the supporting structure of the abutment teeth than the other direct retainers. 5. On the unilaterally designed removable partial dentures, the telescope retainer produced uniform stress distribution on the residual ridge, but produced higher stress concentration at the root apex of the terminal abutment tooth than the other direct retainers. 6. On the unilaterally designed removable partial dentures the circumferential clasp and telescope retainer produced slightly higher stress concentration on the residual ridge and supporting structure of the abutment teeth than the bar clasp and mini- Dalbo attachment.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.263-268
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• 2000

The fretting damage of the contact between Zircaloy-4 and Inconel 600 have Investigated. A fretting wear tester was designed to be suitable for this fretting test. In this study, the number of cycles, slip amplitude and normal load were selected as main factors of fretting wear. As the result of this research the wear volume increased with the increase of loads, slip amplitudes and the number of cycles and was more affected by slip amplitudes rather than by load. According to SEM, stick, partial slip, gross slip were observed on the surface of both specimens and wavy worn surfaces as the typical fretting damage were also Investigated due to accumulation of plastic flow.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.930-938
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• 2004

This paper presents the noise source identification of a car A/V system. There are two different kinds of noise sources noise generated by loading mechanism and rattle noise by externally forced vibration. A dynamometer has been made to produce stationary inertia to the loading mechanism of A/V system. Sound pressure spectra and sound intensity were measured by operating the dynamometer setup as various motor speeds, and the results were analyzed. A dominant rattle noise source about A/V system's components has been found by multi-dimensional spectral analysis. Residual spectrum method was applied for eliminating coherence between the vibration sources. In result, the dominant rattle noise source was identified by partial coherent output spectrum of individual vibration component.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.295-300
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• 2002

To establish an optimum condition in the surface treatment and curing process will be an important parameters for the fabrication of multilayered hybrid composite materials, A17075/CFRP (CARALL : carbon fiber reinforce aluminum laminates). Effects of carbon fiber direction and thickness variation in tensile strength were investigated. And impact damage behavior of carbon fiber reinforce plastic (CFRP) and CARALL were investigated also, it was found that a partial stress increase in order of epoxy adhesive, A17075, CFRP. And the partial stress of CFRP carried out a great portion of applied stress. The impact damage resistance of CARALL was higher than that of CFRP. This is because both side Al sheet of CARALL absorb a great of impact damage.