• Archives of Reconstructive Microsurgery
• /
• v.21 no.2
• /
• pp.131-136
• /
• 2012

Purpose: Arterialized venous flap is useful for reconstruction of the traumatic soft tissue defect in fingers, but insufficient circulation of the traumatic fingers makes surgeons annoying to use the flap. We have grafted flaps in 7 fingers with insufficient vascular bed hoping to expanded the category of the flap. Materials and Methods: Arterialized venous flap have transplanted in 7 fingers from March 2008 through February 2010 and followed up for 4 to 16 months(average 7.2 months). They were all male with a mean age at the time of surgery was 33. The main injury was crushing in 4 degloving, contact burn and saw injury was I respectively. Time interval from injury to flap transplantation was average 3.1. weeks(3 days to 6 weeks). Designed flap size ranges from $8cm{\times}3.5cm$to $4cm{\times}3cm$. Vessel type of flap was one artery with two veins were 5 cases and one artey with one vein 2. Flap type was cutaneous in 3, tendocutaneous 2, neurotendocutaneous 1 and neurocutaneous 1. The circulation state of recipient site was avascular in 2 cases, insufficiency 3 and tip avascular 2. Results: Arterialized venous flap was complete survived in 2 cases, partial necrosis(less than 10%) 3 and failed in 2. Conclusion: An arterialized venous free flap could be a useful procedure for reconstruction in soft tissue or combined defect of the finger despite an avascular or insufficient vascular beds if the recipient beds were free from infection.

• Childhood Kidney Diseases
• /
• v.22 no.2
• /
• pp.86-90
• /
• 2018

Non-infectious complications of peritoneal dialysis (PD) are relatively less common than infectious complications but are a potentially serious problem in patients on chronic PD. Here, we present a case of a non-infectious complication of PD in a 13-year- old boy on chronic PD who presented with symptoms such as hypertension, edema, dyspnea, and decreased ultrafiltration. Chest and abdominal radiography showed pleural effusion and migration of the PD catheter tip. Laparoscopic PD catheter reposition was performed because PD catheter malfunction was suspected. However, pleural effusion relapsed whenever the dialysate volume increased. To identify peritoneal leakage, computed tomography (CT) peritoneography was performed, and a defect of the peritoneum in the left lower abdomen with contrast leakage to the left rectus and abdominis muscles was observed. He was treated conservatively by transiently decreasing the volume of night intermittent PD and gradually increasing the volume. At the 2-year follow-up visit, the patient had not experienced similar symptoms. Patients on PD who present with refractory or recurrent pleural effusion that does not respond to therapy should be assessed for the presence of infection, catheter malfunction, and pleuroperitoneal communication. Thoracentesis and CT peritoneography are useful for evaluating pleural effusion, and timely examination is important for identifying the defect or fistula.

• Archives of Craniofacial Surgery
• /
• v.22 no.5
• /
• pp.268-275
• /
• 2021

Background: The study aimed to evaluate nasal reconstruction techniques customized for Asians. The currently available nasal reconstruction guidelines are based on Caucasian patients, and their applicability is limited in Asian patients due to differences in anatomical and structural features. Methods: A retrospective analysis was performed of the medical records of 76 patients who underwent nasal reconstruction at a single center between January 2010 and June 2020. A comprehensive evaluation was conducted of patients' baseline demographics and clinical characteristics, including age, sex, medical history, defect size and location, reconstructive procedure, pathological diagnosis, postoperative complications, and recurrence. Results: In 59 cases (77%), nasal defects resulted from tumor ablation, and the remaining 17 cases involved post-traumatic (20%) and infection-induced (3%) tissue damage. The most common defect location was the alae, followed by the sidewalls, tip, and dorsum. Forehead flaps were the most commonly used reconstructive technique, followed by nasolabial advancement flaps, rotation flaps, and skin grafts. Each procedure was applied considering aspects of structural anatomy and healing physiology specific to Asians. Complications included nasal deformity, hypertrophic scarring, secondary infection, and partial flap necrosis, but no cases required additional surgical procedures. Tumors recurred in two cases, but tumor recurrence did not significantly affect flap integrity. Conclusion: Nasal reconstruction techniques applied considering Asians' facial features resulted in fewer postoperative complications and higher patient satisfaction than the approaches that are currently in widespread use. Therefore, this study is expected to serve as an essential reference for establishing treatment guidelines for nasal reconstruction in Asians.

• Steel and Composite Structures
• /
• v.1 no.4
• /
• pp.411-426
• /
• 2001

This paper treats the failure analysis of prestressing steel wires with different kinds of localised damage in the form of a surface defect (crack or notch) or as a mechanical action (transverse loads). From the microscopical point of view, the micromechanisms of fracture are shear dimples (associated with localised plasticity) in the case of the transverse loads and cleavage-like (related to a weakest-link fracture micromechanism) in the case of cracked wires. In the notched geometries the microscopic modes of fracture range from the ductile micro-void coalescence to the brittle cleavage, depending on the stress triaxiality in the vicinity of the notch tip. From the macroscopical point of view, fracture criteria are proposed as design criteria in damage tolerance analyses. The transverse load situation is solved by using an upper bound theorem of limit analysis in plasticity. The case of the cracked wire may be treated using fracture criteria in the framework of linear elastic fracture mechanics on the basis of a previous finite element computation of the stress intensity factor in the cracked cylinder. Notched geometries require the use of elastic-plastic fracture mechanics and numerical analysis of the stress-strain state at the failure situation. A fracture criterion is formulated on the basis of the critical value of the effective or equivalent stress in the Von Mises sense.

• Journal of radiological science and technology
• /
• v.2 no.1
• /
• pp.23-29
• /
• 1979

Roentgenographic film has to be handled with greatest care during removal from the packing, loading of the cassettes and loading of the hanger. In the case of prior to or after exposed film is handled with mechanical pressure in darkroom, the most common phenomena are desensitization or sensitization on roentgenographic film. In order to observe these defect occurring on, it, the author studied on change of the densities where the mechanical pressure reached to the roentgenographic film. 1. The optimal minimum and maximum densities in routine chest x-ray film are from 0.25 to 1.47 2. The dependence of the desensitization occurring on film upon the bent degree of film is in the portion to bent degree over $10^{\circ}$ 3. Appearances of the desensitization on film by the curved degree of film is inverse proportion to it's degree below intervals of 3cm. 4. The more unexposed film is bent with nail tip and is pressured with palm, the more desensitization it was appeared upon film size and pressure weight. 5. The most serious area of desensitization produced by many types of mechanical pressure is in the portion of lung apex and outside lung fields. 6. The tendency of desensitization due to mechanical pressure on unexposed film is more serious than sensitization on exposed film in the view of radiologic diagnosis.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.3
• /
• pp.218-223
• /
• 2007

The dissipation of high-power ultrasonic energy at the faces of the defect causes an increase in temperature. It is resulted from localized selective heating in the vicinity of cracks because of the friction effect. In this paper the measurement of size and direction of crack using UET(Ultrasound Excitation Thermography) is described. The ultrasonic pulse energy is injected into the sample in one side. The hot spot, which is a small area around the crack tip and heated up highly, is observed. The hot spot, which is estimated as the starting point of the crack, is seen in the nearest position from the ultrasonic excitation point. Another ultrasonic pulse energy is injected into the sample in the opposite side. The hot spot, the ending point of the crack, is seen in the closest distance from the injection point also. From the calculation of the coordinates of both the first hot spot and the second hot spot observed, the size and slope of the crack is estimated. In the experiment of STS fatigue crack specimen(thickness 14mm), the size and the direction of the crack was measured.

• Archives of Plastic Surgery
• /
• v.48 no.1
• /
• pp.44-48
• /
• 2021

Previously reported nipple-areolar complex reconstruction (NAR) methods involve multiple incisions and wide skin redraping, which increase retraction forces and heighten the risk of nipple-areolar complex (NAC) flattening. We introduce a NAR method using the long V-Y advancement technique that can overcome these disadvantages. A V-shaped flap is designed with the width of the flap base 4-5 mm larger than the diameter of the normal nipple. The flap length is designed to be at least 2.5 times its width. Dissection is performed to the top of the artificial dermal matrix or muscle layer. The nipple is constructed with the same projection as the contralateral side by folding the elevated flap. The tip of the elevated flap is apposed in the middle of the donor defect to minimize the deformity during donor site closure. A 3-point skin suture is applied to the upper third of the folded flap to mold its shape. Using this long V-Y advancement technique, we successfully decreased skin tension in NAC flaps and improved the maintenance of reconstructed nipple projection. The long V-Y advancement technique provides an easy, simple NAR method, effectively maintaining longer nipple projections and reducing breast deformities, especially in Asian women with relatively large nipples.

• Journal of Welding and Joining
• /
• v.21 no.1
• /
• pp.72-79
• /
• 2003

Fatigue behaviour of partially penetrated butt-welded joints in high strength steel plates, in which crack-like structural defect, i.e. lack of penetration(LOP), is inevitably introduced during welding processes, was investigated. Fatigue lives of two types of welded joints, namely X-grooved and K-grooved joints, were experimentally determined first. Observed fatigue crack propagation behaviours of the partially penetrated butt-welds were interpreted through considering 3-dimensional semi-elliptical crack shape in front of the LOP. Based on such interpretation, a fracture mechanical method to estimate stress intensity factors at the crack tip was proposed. Since the fatigue lift of the partially penetrated butt-welds was strongly influenced by the ratio of size of the LOP to thickness, D/t, the D/t was used as a main parameter to calculate the fatigue lift by using the proposed method. Comparison of the fatigue lift obtained experimentally and analytically agreed well with each other. Hence it is suggested that the method used in this work to predict fatigue lift of the partially penetrated butt-welds can be applied to real cases with improved lift-prediction capability.

• Archives of Reconstructive Microsurgery
• /
• v.7 no.2
• /
• pp.122-128
• /
• 1998

Radial forearm flap is one of the most useful skin flap in hand reconstructuion with distally based reverse pedicled or free vascularized fashion. Athors modified that flap into reverse pedicled and free vascularized flap which has advantages of both methods. The modification composed with harvesting flap on recipient side distal forearm just as free flap, than apply it as reverse distal pedicled flap fashion with microvascular anastomosis with distal vascular stump of donor radial vessels. We underwent this method in 5 cases in finger reconstruction from 1996, all of the cases had sucessful results. The advantages of this method are: 1. Thin flap which is compatible to finger skin can harvest from distal forearm with very long vascular pedicle that can be passed under the subcutaneous tunnel which avoid additional skin incisions on the hand. 2. The vessels of donor site and recipient site are same vessel in effected side of forearm, which can preserve contralateral side forearm and hand keep intact. 3. The flap can cover the defects on distal portion of the fingers which is difficult in conventional reversed radial forearm pedicled flap because of limited mobilization of flap due to limitation of pedicle length reach to tip of the fingers.

• Archives of Plastic Surgery
• /
• v.50 no.2
• /
• pp.194-199
• /
• 2023

Moderate soft-tissue defects need stable coverage, ideally with tissue of similar characteristics and low donor site morbidity. We propose a simple technique for the coverage of moderate skin defects in the limbs. It allows intraoperative transformation of a propeller perforator flap (PPF) into a keystone design perforator flap (KDPF) in cases of unsatisfying perforator vessel or in cases of unpredictable intraoperative events. Between March 2013 and July 2019, nine patients with moderate soft-tissue defects (mean defect size 4.5 × 7.6 cm) in the limbs (two on the upper limbs and seven on the lower limbs) were covered using this technique. We performed four PPFs and five KDPFs. The mean follow-up was 5 months. There was one complication, partial distal tip necrosis in a PPF located in the leg, which healed by secondary intention within 3 weeks. The donor site was closed directly in all cases. No functional impairments were noted regardless of the perforator flap utilized. This technique enables us to employ flexible surgical strategies and allows us to make adjustments based on the patient's vascular anatomy.