• Journal of Chest Surgery
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• v.49 no.6
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• pp.485-488
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• 2016

Different suture techniques have been used for anastomosis in coronary artery bypass graft surgery. Bypass surgery may be difficult for patients who have small coronary arteries or marked size discrepancies between target coronary arteries and grafts. For proximal and distal anastomoses, three continuous stitches are first placed in the heel and toe of the small coronary arteries; for sequential anastomosis, an interrupted eight-stitch technique is used. We applied these anastomotic suture techniques in patients requiring coronary artery bypass graft surgery, achieving an early angiographic patency rate of 100%.

• Journal of Chest Surgery
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• v.19 no.3
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• pp.412-420
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• 1986

From 1968 through September 1986, the authors have experienced 34 cases of peripheral arterial surgery using various vascular grafts. Almost all patients [32] were men, and age distribution was variable according to the disease entities. There were twenty eight cases of chronic occlusive peripheral vascular disease including ASO [21], Buerger`s disease [6], Aortoenteric fistula complicating infrarenal abdominal aortic aneurysm [1], four cases of vascular trauma, one case of acute arterial embolism [1] and one case of unknown etiology. The indications of operations for chronic vascular disease was intermittent claudication in 48%, rest pain in 45%, ischemic pregangrene or gangrene in 28%, and sensory change in 10% of patients. Types of operation used were arterial bypass in 28 cases [Aortobifemoral in 5, Aortoiliac in 3, Aortofemoral in 4, Aortoiliac with Aortofemoral in 1, Femorofemoral in 1, Femoropopliteal in 8, Femoroperoneal in 2, Axillofemoral in 3 cases of patients], graft interposition in four and patch angioplasty in three cases. Thirty four prosthetic vascular grafts including Dacron, Gore-Tex, Nylon and two autogenous saphenous vein graft and patch were used for vascular reconstruction in thirty four patients. Unfortunately recently performed one vein bypass was failed immediate postoperatively due to severity of disease and poor case selection. The authors experienced five post operative complications: wound infection [1], graft infection [1], bleeding [1], great saphenous neuralgia [1], pseudoaneurysm [1]. Twenty two of thirty four patients were followed up for more than one month and their cumulative patency rate was 81% [17/22] at 1 month and, 31% [7/22] at 5 month.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.136-142
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• 1988

Between February, 1983, and March, 1987, thirty-one systemic-pulmonary shunts were performed in 28 patients with cyanotic congenital heart disease. Age ranged from 8 months to 28 years [mean age, 5.4 years, Weight ranged from 7 kg to 48 kg [mean weight, 16kg]. There were 4 classic Blalock-Taussig shunts, 5 central polytetrafluoroethylene shunts, 1 aorta-right pulmonary artery shunt with graft, and 21 modified Blalock-Taussig shunts. One patient required another shunt immediately due to insufficient pulmonary blood flow with patent graft. There was no postoperative death. Conduit diameters included 4mm [2 cases], 5 mm [22 cases], and 6 mm [3 cases]. Long term follow up was available in 27 patients [96.4%] with mean period of 20 months [range, 4 months to 49 months]. The effectiveness of shunt was evaluated by cardiac catheterization with angiography [15 patients] or clinically. They showed improvement of systemic oxygen saturation values by 12% and decrease of hemoglobin by 2.3gm/dl [P<0.01]. There were 2 shunt occlusion in central shunts at 32 and 48 months respectively, and one narrowing of graft in modified Blalock-Taussig shunt at 12 months. The patency rate was 91.6% at 24 months for 5 mm grafts in modified Blalock-Taussig shunt.

• International Journal of Vascular Biomedical Engineering
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• v.1 no.1
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• pp.32-40
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• 2003

Axillo-bifemoral (Ax-Fem) bypass are now well accepted for bilateral iliac artery occlusion as the second best option. This extra-anatomical (unnatural) bypasses, however, have various hemodynamic liabilities affecting the patency. Hemodynamic conditions of each different type of Ax-Fem bypass were assessed with computer simulation model to determine the hemodynamically more sound type. Simulation models of five different types of Ax-Fem bypass were constructed. Our investigation based on the computer simulation models have shown distinct differences between two most popular Lazy-S type and Inverted-C type on the distribution of flow volume, shear stress and recirculation zone, etc., though both types have shown similar clinical results. Lazy-S type has shown better hemodyanmic status than inverted-C type. The theoretical advantage of "Lazy-S" type has never been adequately proved for its superiority clinically over the inverted-C type. Inverted-C type is now in more favor with clinically better results in spite of many hemodynamic liabilities including retrograde flow to the branching graft. The improvement of over-all long-term patency rate of various extra-anatomical bypasses is still warranted through proper correction of the hemodynamic liability. Even though clinical outcome of the extra-anatomical bypass has been equal regardless of the type of crossover femoral graft configuration, there are distinct differences on the hemodynamic characteristics among various types of configuration. Further hemodynamic study in the pulsatile flow status is warranted to correct hemodynamic defects with proper modification of various hemodynamic factors of each model.

• Journal of Chest Surgery
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• v.51 no.1
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• pp.8-14
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• 2018

Background: Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients. Methods: All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data - including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention - were collected. Results: The mean age of the patients was $69.4{\pm}11.1years$ and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in the intensive care u nit and in the hospital were 1.5 and 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of $85.3%{\pm}0.09%$ and a 5-year MACCE-free survival rate of $72.8%{\pm}0.1%$. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at $9.7{\pm}10.8months$ postoperatively. Conclusion: MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.478-481
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• 1997

A technique or the preparation of porous polyurethane vascular prostheses was investigated. Small-diameter vessels are not in general clinical use due to their limited long-term biocompatibility and low patency rates in experimental trial. These limits are mainly due to the failure of mechanical unction of the vascular grafts. This failure has been suggested to result partially from compliance mismatch. The long-term patency is considered to depend critically on the properties of the material and the fabrication process of the graft. So the control of pores is very important and main points to develop a available vascular grafts. Two-kind polymer sheets was compared. One was the porous PU-sheet made at room temperature by the solvent/non-solvent exchange. And the other was the porous PU-sheet which was fabricated by thermal phase transition and solvent-/non-solvent exchange using the thermal controller. The polymer sheets had a uniform pore size and pore occupation. According to the result of the above experiments, polyurethane solution was injected into a mold designed or U-type tube. The average pore size and pore occupation were easily changed by changing polyurethane concentration, freezing temperature, and methods. This technique can give a proper pore size ($10{\sim}45\;{\mu}m$) or tissue in growth, and suitable compliances or matching with arteries and veins. Besides, the fabrication of more complicated shaped vessels such as the U-type vascular grafts is easily controlled by using the fixed mold. this method might give a desired compliant graft or artificial implantation with the presently valid medical polymers.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.619-624
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• 2005

Patency of the radial artery plays an important role in the survival of radial forearm fasciocutaneous free flap and artery conduit of coronary artery bypass graft procedure. Even though Allens' test has been used for evaluating the patency of radial artery, the studies on the correlations between risk factors for atherosclerosis and histopathologic findings of radial arteries are rare, until now. Therefore, the authors investigated the correlations between these two factors, and tried to estimate the feasibility of the radial artery in high-risk groups for artherosclerosis. The risk factors for atherosclerosis and lipid profiles were investigated in 38 patients by history taking, physical examinations and blood analysis. And 38 cases of segments of vessel were harvested during the elevation of the flap. The degrees of vessel medial sclerosis were estimated by R values(by Kobayashi and colleagues) that is the median value between the thickness of the intima and that of the media. The measured mean R value was $0.210{\pm}0.05$. Thirty one cases belonged to Grade I(R<0.25), 7 cases belong to Grade II(0.25

• Journal of Chest Surgery
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• v.41 no.2
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• pp.149-159
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• 2008

Background: With increasing coronary bypass and peripheral vascular surgeries, the demand for homologous vascular or synthetic conduits has continued to grow, but wide-spread application has been limited by dismal patency rates. Although cryopreserved allograft valves may provide a suitable alternative, current viability or patency of implanted allograft vascular conduits has been unsatisfactory. Material and Method: We serially analyzed the outcomes of canine femoral artery and saphenous vein allograft implants after storage in either $4^{\circ}C\;or\;-170^{\circ}C$. Result: There were no differences in graft flow rate (patency) (p=0.264), rate of thrombosis (p=0.264), presence of endothelium (p=0.587), or immunohistochemical staining for thrombomodulin (p=0.657) were detected between grafts stored in $4^{\circ}C\;and\;-170^{\circ}C$. Greater flow occurred in the arterial grafts versus the venous grafts (p=0.030), irrespective of the preservation method, with a significantly lower incidence of thrombosis (p=0.030) in arterial allografts. There was a correlation coefficient of -0.654 between thrombosis and positive immunohistochemical staining for thrombomodulin (p=0.006) and a correlation coefficient of 0.520 (p=0.0049) between the endothelial presence and positive immunohistochemical staining for thrombomodulin. The relationship between the presence of endothelium and thrombomodulin expression failed to show any correlation within the first 2 weeks (p=0.306). However, a strong correlation was seen after 1 month (p=0.0008). Conclusion: Tissue storage in either $4^{\circ}C\;or\;-170^{\circ}C$ in 10% DMSO/RPMI-1640 preservation solution preserved grafts equally well. In terms of thrombosis and graft patency, arterial grafts were superior to venous grafts. Considering the poor correlation between thrombomodulin expression and the presence of an endothelium in the implanted graft within the first two weeks, grafts in this period would not be thromboresistant.

• Journal of Korean Neurosurgical Society
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• v.44 no.4
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• pp.228-233
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• 2008

Objective : The standard treatment strategy of intracranial aneurysms includes either endovascular coiling or microsurgical clipping. In certain situations such as in giant or dissecting aneurysms, bypass surgery followed by proximal occlusion or trapping of parent artery is required. Methods : The authors assessed the result of extracranial-intracranial (EC-IC) bypass surgery in the treatment of complex intracranial aneurysms in one institute between 2003 and 2007 retrospectively to propose its role as treatment modality. The outcomes of 15 patients with complex aneurysms treated during the last 5 years were reviewed. Six male and 9 female patients, aged 14 to 76 years, presented with symptoms related to hemorrhage in 6 cases, transient ischemic attack (TIA) in 2 un ruptured cases, and permanent infarction in one, and compressive symptoms in 3 cases. Aneurysms were mainly in the internal carotid artery (ICA) in 11 cases, middle cerebral artery (MCA) in 2, posterior cerebral artery (PCA) in one and posterior inferior cerebellar artery (PICA) in one case. Results : The types of aneurysms were 8 cases of large to giant size aneurysms, 5 cases of ICA blood blister-like aneurysms, one dissecting aneurysm, and one pseudoaneurysm related to trauma. High-flow bypass surgery was done in 6 cases with radial artery graft (RAG) in five and saphenous vein graft (SVG) in one. Low-flow bypass was done in nine cases using superficial temporal artery (STA) in eight and occipital artery (OA) in one case. Parent artery occlusion was performed with clipping in 9 patients, with coiling in 4, and with balloon plus coil in 1. Direct aneurysm clip was done in one case. The follow up period ranged from 2 to 48 months (mean 15.0 months). There was no mortality case. The long-term clinical outcome measured by Glasgow outcome scale (GOS) showed good or excellent outcome in 13/15. The overall surgery related morbidity was 20% (3/15) including 2 emergency bypass surgeries due to unexpected parent artery occlusion during direct clipping procedure. The short-term postoperative bypass graft patency rates were 100% but the long-term bypass patency rates were 86.7% (13/15). Nonetheless, there was no bypass surgery related morbidity due to occlusion of the graft. Conclusion : Revascularization technique is a pivotal armament in managing complex aneurysms and scrupulous prior planning is essential to successful outcomes.

• Archives of Reconstructive Microsurgery
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• v.13 no.2
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• pp.130-135
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• 2004

Purpose : To observe the patency of anastomosis site and the findings of circulation of grafted fibula in osteonecrosis of femoral head treated with vascularized fibular graft by use of digital subtraction angiography. Materials and Methods : 17 cases of 11 patients who underwent vascularized fibula graft for osteonecrosis of femoral head. We performed digital subtraction angiography(DSA) for them at second week postoperatively in 12 cases, at sixth week in 1 case, at sixth month in 2 cases, at twelfth month in 1 case, and eighteenth month in 1 case which had been got DSA at second week before. We observe the patency of pedicle, and the circulation of grafted fibula such as periosteal and intraosseous vessels with time. Results : All cases except one which were thought failure of selective angiogram showed good passage of blood flow through anstomosed pedicle on DSA. We found the differences in appearance of circulation of grafted fibula with time. DSA at 2nd and 6th week postoperatively revealed both of periosteal and intraosseous vessels along the fibula and blood pooling at the tip of fibula. DSA at 6th month showed maintenance of periosteal and intraosseous vessels along the fibula but did not clearly reveal blood pooling at the tip of fibula. The findings of DSA at 12th and 18th month were similar each other. The periosteal vessels were not seen as the grafted fibular bone were incorporated into surrounding femoral bone but intraosseous vessels were still seen. Conclusion : It was thought that DSA could be used for evaluation of the status of pedicle including anastomsed site and vessels of grafted fibula with time. The periosteal vessels of fibula were decreased with time but intraosseous vessels were still seen until 18th month after vascularized fibula graft.