• Archives of Reconstructive Microsurgery
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• 제7권1호
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• pp.15-19
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• 1998

Microsurgical free-tissue transfer has allowed surgeons to salvage injured limbs but choosing appropriate healthy recipient vessels has proved to be a difficult problem. Retrograde flow flaps are established in island flaps. Retrograde flow anastomosis could prevent the possible kinking and twisting of the arterial anastomosis. By not interrupting the proximal blood flow to the fracture or soft tissue defect site, the compromise of fracture or wound healing might be prevented. We wished to estabilish an animal model in rat for a retrograde arterial flow based free flap. Nembutal-anesthetized male rats; weighing 250 to 300 gm, were used. The femoral artery and common carotid artery were exposed and divided. The systemic and retrograde arterial pressure were quantified by utilizing a parallel tubing system connected with peripheral arterial line. In this study, the retrograde flow was not pulsatile and the retrograde arterial pressure was 64-65mmHg, with a mean arterial pressure of 106-109mmHg. An epigastiic skin flap, measuring $3{\times}3cm$, was raised with its vascular pedicle. The epigastric free flap was transfered in the same rat from femoral vessels to carotid vessels in end to end fashion. We anastomosed the donor arteries to the distal parts of the divided recipient arteries and the donor veins to the proximal parts of the recipient veins. Twelve experiments were performed and the transplantations succeeded in 75 percent of them. In the remaining 25 percent, the experiments failed due to thrombosis at the site of anastpmosis, or other causes. This animal model represents an excellent example of retrograde arterial flow free flap transfer that is reliable.

• Investigative Magnetic Resonance Imaging
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• 제5권1호
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• pp.38-42
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• 2001

2D TOF혈관조영술에서 presaturation RF펄스를 사용하여 정맥피에서 나오는 MR신호를 제거하고 얻은 동맥 angiogram에는 band형태로 동맥이 끊어져 나타나는 현상이 자주 보인다. 일부 동맥에서 피의 흐름은 한 심장 주기 동안에 3번의 펄스를 갖는데, 이 중 가운데 펄스는 짧은 기간 동안 역류를 한다. 이 역류하는 동맥피는 정맥피와 같은 방향이기 때문에 presaturation RF펄스에 의해 정맥피 처럼 saturation이 되어서 imaging slice로 흘러 들어가게 될 수 있다. 특히 이러한 경우가 phase encoding step의 dc 부근에서 발생하게 되면 그 때의 단면 영상에서 동맥이 강조가 될 수 없게 되어, 결과적으로 angiogram에는 그 단면을 지나는 동맥의 신호가 없어서 band 형태로 핏줄이 끊어져 나타나게 된다. Imaging slice와 saturation band와의 간격을 변화 시켜 가면서 angiogram을 얻어 봄으로서 이러한 현상을 실험적으로 확인하였다 나아가 saturation band를 rectangle형태에서 ramp 형태로 변경함으로써 이러한 artifacts를 제거 할 수 있는 방법을 제시하였다

• 한국전기전자재료학회논문지
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• 제13권2호
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• pp.106-113
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• 2000

This study describes how a properly calibrated simulation method could be used to investigate the latchup immunity characteristics among the various high energy ion implanted CMOS twin well (retro-grade/BILLI/BL) structures. To obtain the accurate quantitative simulation analysis of retrograde well, a global tuning procedure and a set of grid specifications for simulation accuracy and computational efficiency are carried out. The latchup characteristics of BILLI and BL structures are well predicted by applying a calibrated simulation method for retrograde well. By exploring the potential contour, current flow lines, and electron/hole current densities at the holding condition, we have observed that the holding voltage of BL structure is more sensitive to the well design rule (p+to well edge space /n +to well edge space) than to the retrograde well itself.

• Tuberculosis and Respiratory Diseases
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• 제71권2호
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• pp.126-133
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• 2011

Unilateral pulmonary artery hypoplasia (UPAH) is a rare disease in adults and is frequently accompanied by a congenital cardiac anomaly at a young age. The diagnosis is usually based on computed tomography (CT), angiography, and magnetic resonance imaging (MRI). However, no reports are available on retrograde flow in patients with UPAH. We describe a 68-year-old man with isolated UPAH and retrograde blood flow. He was admitted for dyspnea on exertion for the past 23 years. His diagnosis was delayed, as his symptoms and signs mimicked his underlying pulmonary diseases, such as emphysema and previous tuberculous pleurisy sequelae. A discrepancy was detected between the results of a ventilation-perfusion scan and the CT image. This was resolved by MRI, which showed retrograde blood flow from the right to the left pulmonary artery. Using MRI, we diagnosed this patient with isolated pulmonary artery hypoplasia and retrograde flow.

• Archives of Reconstructive Microsurgery
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• 제15권1호
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• pp.17-25
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• 2006

Twelve cases in eleven patients with segmental bone defects were treated with contralateral fibula free flap and ipsilateral island fibula flap in an antegrade, retrograde or bidirectional flow fashion. Five cases were managed with free flaps and seven were with ipsilateral fibula island transfer. Among seven cases, antegrade fashion was three, retrograde was three, and bidirectional was one. All patients were related with open tibial fractures and its sequelae except one who had open foot bone fracture. According to Gustilo's classification, ten patients were type IIIb and one was type IIIc. Basically, antegrade-flow flaps based on the peroneal vessels as in the conventional free flap were used for the proximal or middle one-third tibial defects. On the contrary, retrograde-flow flaps based on the communicating branch between the peroneal and posterior tibial vessels were used for the middle or distal one-third of the tibia. Bidirection-flow flap based on intact peroneal vessels were used for the middle portion of the tibia. The patients who have undergone ipsilateral fibula island flap had one of the following problems: a previously failed free flap, below-knee amputation of the opposite leg because of open tibial fracture, refusal to use the contralateral sound leg, or poor general condition to stand a lengthy operation. Six of the patients who have got ipsilateral fibula island flap also had an associated fibula fracture on the same leg, which was ultimately used as one of the osteotomy sites. The follow-up period was from 1 to 10 years. Two cases of free flap were failed: one patient had below-knee amputation and the other patient had ipsilateral fibula transfer. Other cases were successful and excellent hypertophy of the transferred fibula was achieved. Time to bone union ranged from 4 to 11 months. Time to full weight bearing was from 5 to 13 months after surgery. All of the transferred fibulas showed hypertrophy after weight bearing. In one case, stress fracture was developed during ambulation, which was healed conservatively. Nonunion occurred in two cases, which were treated with a long leg cast and cancellous bone graft, respectively. Length discrepancy of the legs was noted. The limb was shorter by an average 0.5 cm in three cases, longer by 1.1 cm in one case. In the case of island fibula transfer, limited arc of rotation was not a problem. Other disabling complications were not seen. We believe that these diverse modalities using a vascularized fibula will make us more comfortable to handle major bone defects.

• 대한미세수술학회:학술대회논문집
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• 대한미세수술학회 1996년도 제16차 학술대회
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• pp.159-159
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• 1996

• 동의생리병리학회지
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• 제26권2호
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• pp.253-258
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• 2012

Facial expression was an important communication methods. In oriental medicine, according to the emotion the face has changed shape and difference occurs in physiology and pathology. To verify such a theory, we studied the correlation between emotional facial expressions and meridian and collateral flow. The facial region divided by meridian, outer brow was Gallbladder meridian, inner brow was Bladder meridian, medial canthus was Bladder meridian, lateral canthus was Gallbladder meridian, upper eyelid was Bladder meridian, lower eyelid was Stomach meridian, central cheeks was Stomach meridian, lateral cheeks was Small intestine meridian, upper and lower lips, lip corner, chin were Small and Large intestine meridian. Meridian and collateral associated with happiness was six. This proves happiness is a high importance on facial expression. Meridian and collateral associated with anger was five. Meridian and Collateral associated with fear and sadness was four. This shows fear and sadness are a low importance on facial expression than different emotion. Based on yang meridian which originally descending flow in the body, the ratio of anterograde and retrograde were happiness 3:4, angry 2:5, sadness 5:3, fear 4:1. Based on face of the meridian flow, the ratio of anterograde and retrograde were happiness 5:2, angry 3:4, sadness 3:5, fear 4:1. We found out that practical meridian and collateral flow change by emotion does not correspond to the expected meridian and collateral flow change by emotion.

• Restorative Dentistry and Endodontics
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• 제15권1호
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• pp.97-105
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• 1990

When conventional root canal treatment is failed or contraindicated, retrograde root canal filling following apicoectomy is a valuable procedure, aimed at hermetically sealing the root canal against leakage of irritants from the canal into the periapical tissue. In this in vitro investigation, to analyze apical microleakage electrochemically in teeth with different retrograde filling materials and preparation types, single - rooted tooth was cut 2mm from the apex and each Class I and Slot preparation was prepared. Experimental groups : Group 1. Amalgam filling with cavity varnish in Class I preparation Group 2. Scotchbond 2+Silux filling in Class I preparation Group 3. Gutta percha filling with ZOE cement in Class I preparation Group 4. Amalgam filling with cavity varnish in Slot preparation Group 5. Scotchbond 2+Silux filling in Slot preparation Each specimens was immersed in 1% solution of KCl, and applied a potential of 9V external power supply. Measurements of the current flow were obtained at 1, 2, 3, 7, 9, 12, 14, 18, 21, 25 and 28 day after immerson. Marginal microleakage were compared and evaluated. The results were as follows ; 1. The group filled with composite resin with dentin bonding agent shows lower apical microleakage value than the group filled with amalgam following varnish application (P<0.01). 2. In the group filled with gutta percha, apical microleakage value was the hightest 3. There was no significant difference between Class I cavity and Slot type cavity regardless of the used materials.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.63-70
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• 2000

The properties of ideal retrograde filling materials include the ability to seal the root canal system in three dimensions and well tolerated by periradicular tissues. Biocompatibility testing has been done mainly with cytotoxicity tests using cell culture. Little attention has been paid to the potential adverse influence on the inflammatory and immune reaction in the periapical tissue. The purpose of this study was to investigate the effects of retrograde filling materials on human mononuclear cells in vitro. Freshly mixed and set specimens from six materials (Z100, Tetric Ceram, Fuji II, Fuji II LC, F2000, Compoglass Flow, and ZOE) were eluated with cell culture medium for 24 hours. Cytotoxic effects of these extracts were evaluated by determining cell viability and enzyme activity using MTT and lactate dehydrogenase (LD). The production of inflammatoy bone resorptive cytokine, TNF-${\alpha}$ was measured from human peripheral blood mononuclear cells (PBMC) exposed to the extracts by means of Endogen Human TNF-${\alpha}$ ELISA kit (Wobrun, MA, U.S.A.). Eluates and diluted (1 : 10) eluates with cell culture medium from freshly mixed Fuji IT had cytotoxic effects on mononuclear cells using MTT and LD. However, eluates from set Fuji II were not cytotoxic. Eluates form set ZOE exhibited cytotoxicity with LD test. TNF-${\alpha}$ levels were high in eluates from freshly mixed Fuji II and Z100. Diluted eluates from freshly mixed Z100 and F2000 stimulated the production of TNF-${\alpha}$. However, there were no significant difference in TNF-${\alpha}$ levels compared to controls. These results indicate that some materials could possibly stimulate bone resorption in the periapical tissue by means of the production of bone resorptive cytokine.

• Journal of Chest Surgery
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• 제19권4호
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• pp.543-548
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• 1986

Massive air embolism during cardiopulmonary bypass is uncommon but serious and often lethal complication. Following this catastrophic event, the immediate institution of retrograde arterial blood perfusion via superior vena cava was made to remove air emboli from cerebral circulation. This method was performed by removing the arterial perfusion line from aortic cannula and connecting it to superior vena caval cannula. Then, retrograde perfusion at a flow rate of 2Umin via superior vena cava was carried out for 3 minutes. After air returning from the aortic cannula was identified, each line was connected to the cannulae primarily. In 2 cases who had massive air emboli due to air pumping into arterial line, the postoperative complete recovery resulted from this technique, which was used in conjunction with other therapy postoperatively.