• Journal of Chest Surgery
• /
• v.42 no.4
• /
• pp.487-491
• /
• 2009

Background: Salvaging prosthetic arteriovenous grafts can be performed using surgical or endovascular techniques. We conducted a retrospective analysis to compare the efficacy of these two methods for restoring dialysis graft function. Material and Method: We studied 41 patients who had received surgical thrombectomy with revision (Group A) or percutaneous thrombectomy with angioplasty (Group B) from January 2006 to December 2007. We compared them according to the patient characteristics and the location of stenotic lesions, and we analyzed the post-intervention primary patency rates. Result: 21 patients underwent surgery and 20 patients underwent percutaneous balloon angioplasty. There were no significant differences of the patients' characteristics between the two groups. Venous anastomotic stenosis was the most common cause of graft thrombosis in both groups. In Group A, 90.5% of the grafts remained functional at 6 months and 38.1% remained functional at 12 months. In Group B, 55.0% of the grafts were functional at 6 months and 20.0% of the grafts were functional at 12 months. The post-intervention primary patency rate was significantly better in Group A (p=0.034). Conclusion: Surgical treatment resulted in significantly longer post-intervention primary patency in this study, and this supports its use as the primary method of management for most patients in whom dialysis graft obstruction develops.

• Journal of Chest Surgery
• /
• v.39 no.1 s.258
• /
• pp.42-47
• /
• 2006

Background: The new Multidetector Computed Tomography (MDCT) is useful in visualization of complex coronary artery anatomy. We investigated usefulness comparing of invasive coronary angiography with noninvasive MDCT in judgment of functional degree of coronary arteries grafts after coronary artery bypass graft operation. Material and Method: We analyzed the patency of 52 conduits from 15 patients whom consented to take both 32 Channel MDCT and coronary angiography from November 2003 to November 2004. Comparisons were performed for sensitivity, specificity, positive prediction value and negative prediction value between coronary angiography and 3 dimensional reconstruction image using MDCT. Result: The average graft used was 3.4 $\pm$ 0.8 per patient. Average heart rate during MDCT was 86/minute (Range, 60$\∼$110/minute) without administration of $\beta$-blocker. All patients could hold breath as much as necessary. The average graft patency obtained through corollary angiography was 96.2$\%$. In MDCT group, the sensitivity, the specificity, the positive predictive value and the negative predictive value for diagnosis was 100$\%$, 98.0$\%$, 100$\%$ and 66.6$\%$ respectively. Conclusion: The effectiveness of 32 Channel MDCT may be compared to coronary angiography in grasping about patency and bloodstream of graft conduits after coronary artery bypass graft. Also MDCT has the advantage of noninvasiveness and inexpensiveness compared to coronary angiography.

• Archives of Reconstructive Microsurgery
• /
• v.13 no.1
• /
• pp.43-50
• /
• 2004

One of the major advantages of microsurgical reconstruction for defects of the hand is that these techniques allow for selection of the most ideal tissue to reconstruct a particular defect, thus optimizing the functional and aesthetic outcome. The dorsalis pedis free flap is an excellent reconstructive tool for various hand reconstructions. It has a reliable vasculature with vessels that are relative large on a long pedicle. It provides thin pliable tissue and be innervated by deep peroneal nerve. Coupled with its thinness and pliability, it is ideal for innervated cover of critically sensitive area, especially such as the hand. Thus it can be used as a cutaneotendinous flap, or an osteocutaneous flap. Otherwise, the major criticism with this flap is related to its uncertain vascularity and the donor defect. It is the purpose of this paper to outline our technique of flap elevation and donor site closure and to indicate our current use of this flap in hand reconstruction. We have treated 10 cases (6 burn scar contracture cases, 4 acute hand trauma cases) of hand reconstruction from Dec. 3, 1997 to Mar. 4, 2004 using dorsalis pedis free flap. The key points for sucess in terms of a viable flap and acceptable donor site are the preservation of the critical dorsalis pedis-first dorsal metatarsal vascular axis and the creation of a viable bed for grafting. In addition, we substituted preserved superficial fat skin graft for split thickness skin graft and wet environment was offered for good graft take. Preserved superficial fat skin is defined as composite graft containing epidermis, dermis and superficial fat layer. With sufficient care in flap elevation and donor site closure, a good graft take of preserved superficial fat skin under wet environment can be achieved with no functional disability and minimal cosmetic deformity in donor site. This flap has proved itself to be a best choice for hand reconstruction.

• Journal of Chest Surgery
• /
• v.39 no.10 s.267
• /
• pp.791-794
• /
• 2006

Popliteal artery entrapment syndrome is a rare disorder and lead to claudication and disturbance of blood flow from the results of an abnormal relationship of the popliteal artery to the gastrocnemius muscle, a fibrous band or the popliteus muscle in a young male population. The specific diagnosis is difficult, In most cases, surgical treatment provides a definitive diagnosis of the lesion and is necessary for the patient's recovery. A 34-years-old male was admitted complaining of claudication and pain on left leg. Ankle-brachial index, vascular sonography, CT-angiogram and MRI revealed an occlusion of proximal popliteal artery of left leg. The patient was confirmed as a popliteal artery entrapment syndrome (type IV) that the popliteal artery was entrapped by a fibrous band around the popliteus muscle in the operative fold. Completely occluded fibrotic popliteal artery was removed, and interposition with ipsilateral greater saphenous vein graft was done. After surgery, symptoms of the patient have improved.

• Archives of Reconstructive Microsurgery
• /
• v.13 no.1
• /
• pp.24-28
• /
• 2004

The vascularity of a skin island in fibula osteocutaneous free flap often depends on musculocutaneous perforators that find their origin in the proximal peroneal artery. But a potential drawback has been reported on the unreliability of the skin paddle. The perforating vessels to the skin paddle of the fibula osteocutaneous free flap were rarely derived from a common tibio-fibula trunk, an anterior tibial artery and a posterior tibial artery. Previous studies have emphasized total loss of the overlying skin paddle, if the expected perforating vessels are not present. We report here on our experience that the skin paddle of the fibula osteocutaneous free flap was vascularized not by a peroneal artery but a direct branch of the posterior tibial artery. There were no intraseptal nor intramuscular pedicles in the posterior crural septum which connected to the overlying skin island. Therefore, we performed microsurgical anastomoses between distal peroneal vessels of the fibula and the perforating branches of the posterior tibial vessels of the skin paddle. The anastomosed skin paddle was salvaged with a peroneal flow through vascular anastomosis and was transferred to the bone and intraoral soft tissue defects with the fibula graft. The patient had no evidence of vascular compromise in the postoperative period and showed good healing of the intraoral skin flap.

• Journal of Chest Surgery
• /
• v.41 no.2
• /
• pp.149-159
• /
• 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 Chest Surgery
• /
• v.40 no.4 s.273
• /
• pp.256-263
• /
• 2007

Background: Intimal hyperpiasia is characterized by a proliferation of vascular smooth muscle cells in the intimal layer Epigallocatechin-3-gallate (EGCG) is known to suppress smooth muscle cell proliferation. We propose that EGCG may have a protective effect against the development of intimal hyperplasia through the suppression of smooth muscle cell proliferation. Material and Method: Human umbilical vein endothelial cells (HUVEC) and rat aortic smooth muscle cells (RASMC) were cultured with different concentrations of EGCG, and proliferation and migration speed were measured. In 20 dogs, the autologous jugular veins were interposed into the carotid arteries. For the study group (n=10), the graft was stored for 30 minutes in EGCG solution and 300mM EGCG was applied to the perivascular space after grafting. After 6 weeks, the intimal and medial thickness was measured. Result: The proliferation of RASMC and HUVEC was suppressed with EGCG. The migration of RASMC was suppressed with EGCG, but that of HUVEC was not affected. In the in vivo study, the intimal thickness was thinner in EGCG group than in the control group (p<0.05), but the medial thickness did not show any difference. The intimal/medial thickness ratio was lower in the EGCG group (p<0.05). Conclusion: EGCG suppresses intimal hyperplasia after vascular grafting, and this may be mediated by prevention of migration and proliferation of vascular smooth muscle cells. The use of EGCG may offer new therapeutic modality to prevent intimal hyperplasia.

• Journal of Chest Surgery
• /
• v.34 no.9
• /
• pp.698-703
• /
• 2001

Background: Endovascular stent-graft insertion in aortic diseases is now generally accepted as an attractive alternative treatment modality. We reviewed our clinical experiences of endovascular stent-graft insertion in thoracic aorta. Material and Method: Since 1995, we performed 8 cases of endovasclar stent-graft insertion. Preoperative diagnoses were aortic aneurysms in 4, traumatic aortic ruptures in 3, and ruptured aortic pseudoaneurysm in 1. All procedures were performed in angiography room with the guidance of fluoroscopy. The stent-graft device is a custom-made 0.35mm thickness Z-shaped stainless steel wires, intertwined with each other using polypropylene suture ligation. It is covered with expanded Dacron vascular graft. Result: All procedures were performed successfully. Follow-up studies revealed 2 minimal perigraft leakages. There was no significant leakage or graft migration. 2 patients expired due to multiple organ failure and fungal sepsis. Other survivors(6) are doing well. Conclusion: Endovascular stent-graft insertion is relatively saft and effective treatment modality in the managment of various types of aortic diseases. In may be an effective alternative in aortic diseases of great surgical risk.

• Journal of Chest Surgery
• /
• v.39 no.4 s.261
• /
• pp.261-268
• /
• 2006

Background: Current vascular prostheses are still inadequate for reconstruction of small-diameter vessels. Autologous pericardium can be a good alternative for this purpose as it already possesses good blood compatibility and shows a mechanical behavior similar to that of natural arteries. However, the clinical use of autologous pericardial tissue as a small-diameter vascular graft has limitations due to mixed outcomes from uncertain biological behavior and difficulty to gain reliable patency results in animal experiments. To study this issue, we implanted fresh and glutaraldehyde-treated autologous pericardium as small-diameter arterial grafts in dogs, and compared their time-related changes histologically. Material and Method: As a form of 5mm-diameter arterial graft, one pair of autologous pericardial tissue was used for comparison between the glutaraldehyde-treated and the glutaraldehyde-untreated grafts in the bilateral carotid arteries in the same dog. The patency of the grafts were evaluated at regular intervals with Doppler ultrasonography. After the predetermined periods of 3 days, 2 weeks, 1 month, 3 months and 6 months, the grafts in each animal were explanted. The retrieved grafts were processed for light and electron microscopic analyses following gross observation. Result: Of 7 animals, 2 were excluded from the study because one died postoperatively due to bleeding and the other was documented as one side of the grafts being obstructed. All 10 grafts in the remaining 5 dogs were patent. Grossly, a variable degree of thromboses were observed in the luminal surfaces of the grafts at 3 days and 2 weeks, despite good patency. Pseudointimal smooth blood-contacting surfaces were developed in the grafts at f month and later. By light microscopy, mesothelial cell layers of the pericardial tissue were absent in all explanted grafts. Newly formed endothelial cell layers on the blood-contacting surface were observed in both the glutaraldehyde-treated and fresh grafts at 3 months and later. The collagen fibers became degraded by fragmentation in the fresh graft at 1 month and In the glutaraldehyde-treated graft at 3 months. At 6 months, the collagen layers were no longer visible in either the glutaraldehyde-treated or fresh grafts. By electron microscopy, a greater amount of coarse fibrin fibers were observed in the fresh grafts than in the glutaraldehyde-treated grafts and, more compact and well-arrayed layers were observed in the glutaraldehyde-treated grafts than in the fresh grafts. Conclusion: The glutaraldehyde-treated small-diameter pericardial arterial grafts showed a better endothelialization of the blood-contacting surface and a slower fragmentation of the collagen layers than the fresh grafts, although it has yet to be proven whether these differences are so significant as to affect the patency results between the groups.

• Journal of Chest Surgery
• /
• v.23 no.1
• /
• pp.174-177
• /
• 1990

Aortic dissection is a challenging disease and the causes of that are well-known. Blunt chest trauma is one of the causes of aortic dissection. In such cases, nearly all cases involves the isthmic portion of descending aorta, but ascending aorta is involved in about 10. We experienced a patient who had ascending aortic dissection due to automobile accident and who showed spontaneous rupture of the aorta during operation. In this case, after installation of aortic line via left femoral artery, ascending aorta ruptured and a large amount of blood gushed out, which was suckered by cardiotomy sucker. A little delay of cardiopulmonary bypass may cause the fatal outcome in such a case because the bleeding from aorta is too much to be controlled. Fortunately, we controlled the bleeding with cardiopulmonary bypass and got the good outcome of this patient by interpositioning the vascular graft. One should suspect the possibility of aortic dissection in blunt chest trauma, and prepare all the facilities against bleeding due to rupture.