• Journal of Chest Surgery
• /
• v.46 no.5
• /
• pp.319-327
• /
• 2013

Strategic planning is integral to any operation but complexity varies immensely and therefore the effort necessary to create the optimal plan. The previous three reports have discussed individual conduits and herein is an attempt to present approaches to common situations which the author favors. Although much has been learned over 45 years about use and subsequent behavior of venous and arterial grafts we continue to learn and, as a result, evolve new strategies or modify those now popular. Thus the reader must recognize that in spite of trying to be balanced and inclusive all surgeons have personal opinions and also prejudices which influence the approach taken and which may not be the optimal one for others or for the patient.

• Journal of Chest Surgery
• /
• v.33 no.10
• /
• pp.830-833
• /
• 2000

Homograft has been the conduit of choice in various types of congenital malformations which require right ventricular outflow tract reconstruction. However it has been proven to be less than ideal in young age group because of early failure of the conduite due to valve dysfunction and calcification. Furthermore limitation of availability of homograft particularly small sized conduits for neonates and infants is the most serious problem. A 19 month old female patient with pulmonary atresia and ventricular septal defect was operated on with a bovine jugular venous valved conduit as an alternative to the homograft for her right ventricular outflow tract reconstruction. Postoperative hemodynamic performance of the conduit was excellent without pressure gradient or valve regurgitation. With this early result bovine jugular venous valved conduit seems to be another excellent conduit because of good hemodynamics and size availability but long term follow up is necessary.

• Journal of Chest Surgery
• /
• v.28 no.6
• /
• pp.533-541
• /
• 1995

We recently developed a new model of moving actuator type totally implantable artificial heart[TIAH , based on the reverse position of the aortic and pulmonary conduits. This concept was proposed by one of surgeons in our team[Joon-Ryang Rho, M.D. to facilitate anatomical fitting of TIAHs. The moving actuator type electromechanical TIAH consisted of the left and right blood sacs, and the moving actuator including a motor. The inverted umbrella type polyurethane valves were used in the blood pumps. The aortic conduit was positioned anterior to the pulmonary conduit, which was the opposite relation to the conventional configuration of other total artificial hearts. We also adapted slip-in connectors for the aortic and pulmonary conduits. Two sheep , weighing 60-69 kg, were used for implantation. After small cervical incision and trans-sternal bilateral thoracotomy, cardiopulmonary bypass [CPB was administered using an American Optical 5-head pump and a membrane oxygenator[Univox-IC, Bentley . The anterior and posterior vena cavae were drained separately for venous return. An arterial return cannula was inserted into the right common carotid artery. During CPB, almost all of the ventricular myocardium was excised down to the atrioventricular groove and the artificial heart was implanted. We achieved 3-day survival in the first sheep and 2-day survival in the second. The day after operation the first sheep was successfully extubated and the second sheep was weaned from a respirator with good condition. After extubation, the first sheep walked around in the cage and fed herself. Serial laboratory and hemodynamic examinations were done during the experiments. In both sheep, pulmonary dysfunction was gradually developed, which was accompanied by acute renal failure. The animals were sacrificed and autopsy was done. Unexpected pregnnacy was incidentally found in both sheep. To our knowledge this is the first report of significant survival cases in the orthotopic implantation of electric TIAH using sheep.

• 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.20 no.3
• /
• pp.536-543
• /
• 1987

The Fontan procedure was physiological correction which was initially applied to tricuspid atresia. We had used the modified Fontan operation in 8 cases at National Medical Center, Seoul, from Aug. 1984 to Oct. 1986. Age range was 20 months to 15 years [mean: 9 years] and male: female ratio was 5:3. 5 patients had tricuspid atresia [lb: 2 cases, Ic: 1 case, lib: 1 case, & llc: 1 case], 2 Patients had univentricular heart of left ventricular type, and one patient had transposition of great arteries with complete endocardial cushion defect. The operative principle was direct anastomosis between right atrium and pulmonary artery, whether main pulmonary artery or right pulmonary artery without any conduits. Postoperatively all patients needed high central venous pressure for adequate hemodynamic status in both survival [20-24 CmH2O] and mortality groups [20-24 CmH2O]. The fatal complications were as follows: empyema with bronchopleural fistula [1 case], bleeding tendency & brain damage [1 case], low cardiac output syndrome & acute renal failure [2 cases], and right to left shunt of unknown origin [1 case]. There were 5 hospital deaths; 3 of 5 tricuspid atresia patients, 1 of 2 univentricular heart patients, and 1 of 1 transposition of great arteries with complete endocar4ial cushion defect patient. The overall mortality was 62.5%. 3 survivors were nearly compatible with Choussat & Fontan criteria. Thus appropriate patient selection and experienced surgical technique were required for good results.

• Journal of Chest Surgery
• /
• v.38 no.5 s.250
• /
• pp.349-356
• /
• 2005

Background: Arterial conduits using in coronary artery bypass grafting (CABG) have been known a great long term patency rates, and improved short and long term clinical outcomes. It has been reported that Off pump CABG has better clinical results than CABG using cardiopulmonary bypass. To evaluate the advantage of arterial conduits over venous conduits and to avoid the adverse effects of cardiopulmonary bypass, we performed total arterial Off pump CABG. Material and Method: From January 2001 to October 2004, Off pump CABG using only arterial conduits was performed on 325 patients with a mean age of $59.3\pm11.9$ years ($36\~83$). Mean ejection fraction was $55.4\pm14.0\%\;(15\~86).$ Angiography showed left main disease or triple-vessel disease in $81.9\%$ of the patients. Indications of using arterial conduits was stenosis $\ge50\%$ of left anterior descending artery, stenosis $\ge80\%$ of branches of left circumflex artery, and stenosis $\ge90\%$ of right coronary artery and its branches. Multi-slice computed tomography was performed on 194 patients to evaluate the short term patency rates. Result: A total of 928 distal anastomoses were performed and the average anastomoses per a patient were $2.86\pm0.78$. There was 1 operative mortality. Postoperative complications were mediastinitis in 6 patients ($1.8\%$), renal failure in 4 patients ($1.2\%$), perioperative myocardial infarction in 3 patients ($0.9\%$), reoperation for bleeding in 3 patients ($0.9\%$). There was no postoperative stroke. Patency rate of arterial conduits was $99.3\%$ (581/585). There were 4 stenoses or competitive flows in 2 radial arteries and 2 right internal mammary arteries. Conclusion: Total arterial Off pump CABG appears to be safe, showing a low surgical mortality and morbidity and excellent short term patency rates of arterial conduits.

• Archives of Reconstructive Microsurgery
• /
• v.6 no.1
• /
• pp.29-38
• /
• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.