Effect of Brain Hypothermia on Ischemic Injury and Matrix Metalloproteinase Activity in Focal Cerebral Ischemia

BACKGROUND: Effects of hypothermia have been demonstrated in experimental animals with cerebral ischemia. Although the exact mechanisms of hypothermic effects are unknown, decrease of the blood-brain barrier (BBB) permeability, inhibition of free radical generation, and anti-inflammatory actions have been suggested. Matrix metalloproteinases (MMPs) may play a role in the hypothermic effect because they are known to mediate neuro-inflammatory responses and BBB breakdown. METHODS: The rats were subjected to 2 hours of middle cerebral artery occlusion (MCAO) and 18 hours of reperfusion. The normothermia group was maintained at 37 degrees C. Moderate hypothermia was induced by maintaining the temperature at 32 degrees C during MCAO in the intra-ischemic hypothermia (IH) group, and for 2 hours immediately after reperfusion in the postischemic hypothermia (PH) group. The infarction size in coronal slices were measured after 2, 3, 5-triphenyltetrazolium chloride stain. By gelatin zymography, the activity of MMP-2 and MMP-9 was measured. Evans blue extravasation methods were used to determine the BBB disruption. RESULTS: The infarction size was significantly decreased in the IH group compared to the normothermia group. The MMP-2 and MMP-9 activities in the ischemic hemispheres was significantly decreased in the IH group compared to the normothermia group. In the PH group, only the MMP-2 activity was significantly decreased compared to the normothermia group. Infarction size was significantly correlated with MMP-2 (r=0.688), and MMP-9 (r=0.707) activities. The disruption of BBB was significantly reduced in the IH group compared to the normothermia group. CONCLUSIONS: Intra-ischemic hypothermia effectively attenuated ischemic injury. Hypothermia-mediated inhibition of MMP-2 and MMP-9 activities may contribute to this protective effect.

Diagnostic and Surgical Codes ofr National Thoracic and Cardiovascular Database / 대한흉부외과학회지

No abstract available.

Surgical Management of Aortic Insufficiency in Behcet's Disease / 대한흉부외과학회지

BACKGROUND: Cardiac involvement of Behcets disease is very rate, however, the prognosis of Behcet disease depends on cardiovascular complications. In this article, we described surgical treatment of aortic insufficiency with Behcets disease. MATERIAL AND METHOD: From March 1986 to February 1998, we operated on 10 patients of aortic insufficiency with Behcets disease. Male to female ratio was 8 to 2, and age ranged from 21 to 40 years(mean 32.8 years). There were 8 patients with evidence of Behcets disease and another 2 patients had some suspicious findings of Behcets disease(i.e., prosthetic value dehiscence, hypertrophied aortic wall). Adequate preoperative medical treatment for Behcets disease was done in 3 patients. RESULT: We performed 24 open heart surgeries in 10 patients. Redo value replacements using prosthetic valves were done in 4 patients. Among them, 2 patients were operated on for a second redo valve replacement and one of them operated on for a 4th and 5th operation because of recurrent paravalvular leakage. These 4 patients expired. 1 patient who had undergons tissue value replacement is alive. 1 patient who underwent Cabrol operation expired dut to rupture of graft anastomosis site. We used homografts in 3 patients. In 2 of them, we performed aortic root replacement and subcoronary valve replacement in another patient. The patient who underwent subcoronary valve insertion had remnant aortic insufficiency, so we are closely observing him. We also performed Ross operation in a 24 year old female who suffered severs aortic insufficiency and endocarditis after aortic valvuloplasty. 5 patients are alive and mean follow up duration is 49.0 months. Among them, we used homografts or sutografts in 4 patients. We could observe excellent clinical results in the patients who underwent aortic root replacement using homograft and they were treated medically for Behcets disease. CONCLUSIONS: We concluded that adequate preporative diagnosis, clinical suspicion, and periopertive medical treatment for Behcets disease are very important for the result of surgical management of aortic insufficiency with Behcets disease. The use of homograft or autograft was helpful for the healing of anastomosis site and we should carefully observe the long term follow up results.

The Changes of Cerebral Metabolic and Hemodynamic Parameters , Brain Histology , and Serum Levels of Neuron-Specific Enolase During Retrograde Cerebral Perfusion Under Pofound Hypothermic total Circulatory Arrest in Pigs / 대한흉부외과학회지

BACKGROUND: Retrograde cerebral perfusion(RCP) is currently used for brain protection during aorta surgery, however, for the safety of it, various data published so far are insufficient. We performed RCP using pig and investiaged various parameters of cerebral metabolism and brain injury after RCP under deep hypothermia. MATERIAL AND METHOD: We used two experimental groups: in group I(7 pigs, 20 kg), we performed RCP for 120 minutes and in group II (5 pigs, 20 kg), we did it for 90 minutes. Nasopharyngeal temperature, jugular venous oxygen saturation, electroencephalogram were continuously monitored, and we checked the parameters of cerebral metabolism, histological changes and serum levels of neuron-specific enolose(NSE) and l actic dehydrogenase(LDH). Central venous pressure during RCP was mainained in the range of 25 to 30 mmHg. RESULT: Perfusion flow rates(ml/min) during RCP were 130+/-57.7(30 minutes), 108.6+/-55.2(60 minutes), 107.1+/-58.8(90 minutes), 98.6+/-58.7(120 minutes) in group I and 72+/-11.0(30 minutes), 72+/-11.0(60 minutes), 74+/-11.4(90 minutes) in group II. The ratios of drain flow to perfusion flow were 0.18(30 minutes), 0.19(60 minutes), 0.17(90 minutes), 0.16(120 minutes) in group I and 0.21, 0.20, 0.17 in group II. Oxygen consumptions(ml/min) during RCP were 1.80+/-1.37(30 minutes), 1.72+/-1.23(60 minutes), 1.38+/-0.82(90 minutes), 1.18+/-0.67(120 minutes) in group I and 1.56+/-0.28(30 minutes), 1.25+/-0.28(60 minutes), 1.13+/-0.26(90 minutes). We could observe an decreasing tendency of oxygen consumption after 90 minutes of RCP in group I. Cerebrovascular resistance(dynes sec cm-5) during RCP in group I incrased from 71370.9+/-369145.5 to 83920.9+/-49949.0 after the time frame of 90 minutes(p<0.05). Lactate(mg/min) appeared after 30 minutes of RCP and the levels were 0.15+/-0.07(30 minutes), 0.18+/-0.10(60 minutes), 0.19+/-0.19(90 minutes), 0.18+/-0.10(120 minutes) in group I and 0.13+/-0.09(30 minutes), 0.19+/-0.03(60 minutes), 0.29+/-0.11(90 minutes) in group II. Glucose utilization, exudation of carbon dioxide, differences of cerebral tissue acidosis between perfusion blood and drain blood were maintained constantly during RCP. Oxygen saturation levels(%) in drain blood during RCP were 22.9+/-4.4(30 minutes), 19.2+/-4.5(60 minutes), 17.7+/-2.8(90 minutes), 14.9+/-2.8(120 minutes) in group I and 21.3+/-8.6(30 minutes), 20.8+/-17.6(60 minutes), 21.1+/-12.1(90 minutes) in group II. There were no significant changes in cerebral metabolic parameters between two groups. Differences in serum levels of NSE and LDH between perfusion blood and drain blood during RCP showed no statistical significance. Serum levels of NSE and LDH after resuming of cardipulmonary bypass decreased to the level before RCP. Brain water contents were 0.73+/-0.03 in group I and 0.69+/-0.06 in group II and were higher than those of the controls(p<0.05). The light microscopic findings of cerebral neocortex, basal ganglia, hippocampus(CA1 region) and cerebellum showed no evidence of cerebral injury in two groups and there were no different electron microscopy in both groups(neocortex, basal ganglia and hippocampus), but they were thought to be reversible findings. CONCLUSIONS: Although we did not proceed this study after survival of pigs, we could perform the RCP successfully for 120 minutes with minimal cerebral metabolism and no evidence of irreversible brain damage. The results of NSE and LDH during and after RCP should be reevaluated with survival data.

Early Results of Mitral Valve Reconstruction in Mitral Regurgitation / 대한흉부외과학회지

BACKGROUND: Reconstruction surgery of mitral valve regurgitation is now considered as an effective operative technique and has shown good long-term results. Although reconstructive surgery of mitral valve has been performed since 1970s, we have started only in early 1990s in full scale because of small number of the mitral regurgitation compared to mitral stenosis and lack of knowledge from the viewpoint of patients and physicians. MATERIAL AND METHOD: From January 1992 to December 1996, 100 patients underwent repair of the mitral valve for mitral regurgitation with or without mitral stenosis in Seoul National University Hospital. 45(45%) of the patients were men and 55(55%) were women. The mean age was 39.9+/-14.4 years. The causes of the mitral regurgitation were rheumatic in 61, degenerative in 28 and others in 11. According to the Carpentier's pathological classification of mitral regurgitation 5 patients were type I. 55 patients were type II and 40 patients were type III. 7 patients underwent concomitant aortic valvuloplasty and 8 patients underwent aortic valve replacement. 7 patients underwent Maze operation or pulmonary vein isolation. RESULT: There were no operative death but 3 major operative complications: 2patients were postoperative low cardiac output syndrome(needed intra-aortic ballon pump support) and 1 patient was postoperative bleeding. There was one late death(1.0%) The cause of death was sepsis secondary to acute bacterial endocarditis. 3 patients required reoperation for recurred mitral regurgitation. There were no statistically significant risk factors for reoperation. The other 96 patients showed no or mild degree of mitral regurgitation 99 survivors were in NYHA functional class I or II. There were two throumboembolisms but no anticoagulation-related complications. CONCLUSIONS: We concluded that mitral valve repair could be performed successfully in most cases of mitral regurgitation even in the rheumatic and combined lesions with very low operative mortality and morbidity. The early results are very promising.

Lecompte Procedure in Complex Congenital Heart Diseases / 대한흉부외과학회지

BACKGROUND: This study is to evaluate the effectiveness and application of Lecompte procedure as a treatment for various complex cardiac anomalies with pulmonary outflow tract obstruction. Methods: Between July 1988 and December 1997, 44 patients underwent Lecompte procedure in Seoul National University Children's Hospital. The male to female ratio was 24 to 20 and the mean age was 29.2 months (range, 3 to 83). Of these patients, 28 (63.6%) had transposition of great arteries with ventricular septal defect and pulmonary stenosis (or pulmonary atresia), 14 (31.8%) had double outlet right ventricle with pulmonary stenosis (or pulmonary atresia), and so on. The principles of the technique are 1) extension of the ventricular septal defect or conal resection, 2) construction of a intracardiac tunnel connecting the left ventricle to the aorta, and 3) direct connection, without a prosthetic conduit, of the pulmonary trunk to the right ventricle. RESULTS: There were 3 in-hospital deaths and their causes were sustained hypoxia, myocardial failure, and sepsis, respectively. There was 1 late death due to sepsis. Reoperations were performed in 6 patients who had pulmonary outflow tract obstructions (4 cases), residual muscular ventricular septal defect (1 case), and recurrent septic vegetation (1 case). The cumulative survival rates by the Kaplan-Meier method were 92.7%, 92.7%, and 92.7% at 1, 2, and over 4 years. The reoperation free survival rates were 92.7%, 92.7%, and 70.2% at 1, 3, and over 5 years. Among the risk factors for the operative death, aortic cross clamping time had statistical significance (p0.05). CONCLUSIONS: Our review suggests that Lecompte procedure is an effective treatment modality for various complex cardiac anomalies with pulmonary outflow tract obstruction. Repair in early age is possible and the rates of mortality and morbidity are also acceptable.