Effect of Aprotinin on Changes in Plasma Thromboxane B2 and Endothelin-1 Concentratin after Extracorporeal Circulation / 대한흉부외과학회지

BACKGROUND: Thromboxane A2 and endothelin-1 are the potent vasoconstrictors affecting pulmonary pathophysiology in response to whole body inflammatin following CPB. Aprotinin, as an antiiflammatory agent, may decrease the release of such vasoactive substance from pulmonary tissues, preventing pulmonary hypertension after cardiopulmonary bypass. MATERIAL AND METHOD: Ten mongrel dogs(Bwt. ac. 20kg) were subjected to cardioupulmonary bypass for 2 hours and postbypass pulmonary vascular resistance(0, 1, 2, 3 hours) were compared with prebypass level. The dogs were divided into 2 groups; control group(n-5) and aprotinin group(n=5). In the aprotinin group, aprotinin was administered as follows; 50,000 KIU/kg mixed in pump priming solution, 50,000 KIU/kg prebypass intravenous infusion over 30 minutes, 10,000 KIU/kg/hour postbypass continuous infusion. Prebypass and postbypass 0, 1, 2, 3 hour pulmonary vascular resistance were measured. At prebypass and postbypass 0, 90, 180 minutes, blood samples were obtained from pulmonary arterial and left atrial catherers for the assay of plasma thromboxane B2 a stable metabolite of thromboxane A2, and endothelin-1 concentrations. RESULT: The ratios of pustbypass over prebypass pulmonary vascular at postbypass 0, 1, 2, 3 hours were 1.28+/-0.20, 1.82+/-0.23, 1.90+/-0.19, 2.14+/-0.18 in control group, 1.58+/-0.18, 1.73+/-0.01, 1.66+/-0.10, 1.50+/-0.08 in aprotinin group ; the ratios gradually increased in control group while decreased or fluctuated after postbypass 1 hour in aprotinin group. There was statistically significant difference between control group and aprotinin group at postbypass 3 hours(P=0.014). Pulmonary arterial plasma concentration of thromboxane B2(pg/ml) at prebypass, postbypass 0, 90, 180 minutes were 346.4+/-61.9, 529.3+/-197.6, 578.3+/-255.8, 493.3+/-171.3 in control group, 323.8+/-118.0, 422.6+/-75.6, 412.3+/-59.9, 394.5+/-154.0 in aprotinin group. Left atrial concentrations were 339.3+/-89.2, 667.0+/-65.7, 731.2+/-192.7, 607.5+/-165.9 in control group, 330.0+/-111.2, 468.4+/-190.3, 425.4+/-193.6, 4.7.3+/-142.8 in aprotinin group. These results showed decrement of pulmonary thromboxane A2 generation in aprotinin group. Pulmonary arterial concentrations of endothelin-1(fmol/ml) at the same time sequence were 7.84+/-0.31, 13.2+/-0.51, 15.0+/-1.22, 16.3+/-1.73 in control group, 7.76+/-0.12, 15.3+/-0.71, 22.6+/-6.62, 14.9+/-1.11 in aprotinin group. Left atrial concentrations were 7.61+/-17.2, 57.1+/-28.4, 18.9+/-18.2, 31.5+/-20.5 in control group, 5.61+/-7.61, 37.0+/-26.2, 28.6+/-21.7, 37.8+/-30.6 in aprotinin group. These results showed that aprotinin had no effect on plasma endothelin-1 concentration after cardiopulmonary bypass. CONCLUSIONS: Administration of aprotinin during cardiopulmonary bypass could attenuate the increase in pulmonary vascular resistance after bypass. Inhibition of pulmonary thromboxane A2 generation was thought to be one of the mechanism of this effect. Aprotinin had no effect on postbypass endothelin-1 concentration.

Valvuloplasy in Mitral Regurgitation: available option in Young rheumatic mitral regurgitation patients / 대한흉부외과학회지

BACKGROUND: The present study was undertaken to assess the effectiveness of surgical repair as a method of treatment for rheumatic mitral regurgitation by comparing the results of mitral valvuloplasty(MVP) in rheumatic mitral regurgitation and degenerative mitral regurgitation. MATERIAL AND METHOD: Among the 184 MVP patients between January 1995 to December 1998, 49 Rheumatic mirtal regurgiation patients(Group I) and 72 degenerative mirtal regurgitation(Group II) patients were studied. The mean age in group I was 36.3+/-14.6(16-74) and in group II, 52.5+/-13.4(14-77) years. The total follow up duration was 72.2patient years for group I and 77.2 patient years for group II. The Echocardiography was performed preoperatively, at 6months and 1 year postoperatively, and then yearly thereafter in both groups. RESULT: Preoperatively, there were no hemodynamic differences between the two groups. The preoperative mitral regurgitation was 3.9+/-0.4 in group I and 3.9+/-0.3 in group II, but on follow up, both groups showed decrease of grade of regurgitation to 0.9+/-0.9 in group I and 0.8+/-0.7 in group II. The mitral valve area or the mean transmitral pressure gradient was not significantly different between the two groups. There was neither early nor late mortality in either group and the reoperation rate in group I was 1.4% per patient year and 2.6% per patient year in group II. The rate of thromboembolism in group I was 2.8% per patient year and 1.3% per patient year in group II. There was one bacterial endocarditis in group I. Statistical analysis of the data between the two groups failed to reveal any significant differences. CONCLUSION: Although the results of a long term follow up will be required, the current intermedite term study showed that repair was a viable option in the treatment of rheumatic mitral regurgitation.

Ruptured Left Sinus of Valsalva Aneurysm into the Left Ventricle / 대한흉부외과학회지

We report a case of ruptured sinus of Valsalva aneurysm in 48-year-old male, presenting the symptom of congestive heart failure. Echocardiography showing a hairpin-like sac ex tended from the left coronary sinus to the left ventricle adjacent to the anterior mitral valve leaflet, suggested ruptured sinus of Valsalva aneurysm or aorto-left ventricular tunnel. Operative findings revealed that left sinus of Valsalva aneurysm had multiple openings faced left ventricle, 7 mm in diameter, 20 mm in length. The proximal opening was closed with bovine pericardium and distal openings were closed with spaghetti pledgeted reinforced sutures. The patient was discharged on the 14th postoperative day, and follow up for 8 months uneventfully. This case was reported for its rarity and to describe the techniques of surgical repair.

Right Anterolateral Thoracotomy for Cardiac Surgery in the Adult / 대한흉부외과학회지

BACKGROUND: To secure a rapid and safe approach which is at the same time cosmetically appealing, we employed the right anterolateral thoracotomy incision for repair of atrial septal defects and valvular heart diseases in the adult. MATERIAL AND METHOD: Between October 1989 and June 1998, 44 adult patients underwent open heart surgery through right anterolateral thoracotomy at our institution. Operative time, cardiopulmonary bypass time, aortic cross clamp time, blood loss until chest tube removal, length of ICU stay, days to discharge, and survival were compared with those that received cardiac surgery via conventional sternotomy. RESULT: No significant differences were observed between the two groups. There was no death and no additional morbidity directly related to this approach. Cosmetically satisfying results were obtained with safety using the right anterolateral thoracotomy approach. CONCLUSION: Our data show that the right anterolateral thoracotomy approach is a safe alternative to conventional median sternotomy as it offers excellent exposure and aesthetically more acceptable wounds while not adding on to the operative risks.

Histological Characteristics of Right Gastroepiploic Artery for Coronary Artery Bypass Graft / 대한흉부외과학회지

BACKGROUND: Long term patency of arterial graft has been better than venous graft and redo coronary artery bypass grafting has been increasing, therefore, there has been an increasing need for alternative arterial grafts except internal thoracic artery(ITA). MATERIAL AND METHOD: Right gastroepiploic arteries(RGEA) were harvested from 100 patients who had received gastrectomy for gastric cancer or ulcer. ITAs were obtained from 10 patients undergoing coronary artery bypass grafting. The length of RGEA was measured from the pyloric ring. Items of the morphometric and histologic study at the pyloric ring and sites of the 10cm and 20cm RGEA from the pyloric ring were luminal diameter, intimal thickness, medial thickness, wall thickness, degree of intimal hyperplasia, intimal thickness, medial thickness, wall thickness, degree of intimal hyperplasia, intimal thickness index, medial thickness index, and the number of discontinuities of the internal elastic lamina. Similar items were applied to the proximal site of ITAs. RESULT: The length of RGEA was 23+/-2.7cm(range 17~31cm). Comparing the 20cm RGEA with ITA, intimal thickness, medial thickness, wall thickness, and degree of intimal hyperplasia did not show any difference(p>0.05). However, 20cm RGEA was greater than ITA at the luminal diameter, intimal thickness index, and the number thickness and wall thickness in each site of the RGEA(pyloric ring, 10cm, 20cm) decreased from the pyloric ring to the distal sites(p<0.05). The degree of intimal hyperplasia and the number of discontinuities of the internal elastic lamina did not show any difference between the pyloric ring and 10cm, however, those of 20cm were smaller than these sites(p<0.05). RGEA had more number of discontinuities of the internal elastic lamina and rich smooth muscle cells in the media than ITA. CONCLUSION: The length and diameter of RGEA is good enough to reach most of the coronary arteries. Moreover, long term patency of RGEA may be improved, if anastomosed in the distal site.

A Modification of Maze III Procedure to Improve Left Atrial Function / 대한흉부외과학회지

BACKGROUND: The current study was undertaken to investigate the results of a modification in the conventional Maze III Procedure devised by the authors. The aim of the technical modification was in improving the left atrial contractility. MATERIAL AND METHOD: Between July 1997 and December 1998, 34 patients with chronic atrial fibrillation for more than 1 year duration underwent a modified Maze III procedure. The assessment of the left atrial function was made by various echocardiographic measurements and SA nodal recovery was evaluated by HRV Holter monitoring. RESULT: All 34 patients were in sinus rhythm. On echocardiography, right atrial contraction was detected in 32 patients(94.1%) and left atrial contraction in 33 patients(97.1%). The echocardiographic A wave at 1, 6, and 12 months or more were 50.5+/-31.5, 62.1+/-25.1, 66+/-20.6 cm/sec, respectively, and the E wave measurements at the same time points were 152+/-31.1, 134.4+/-35.2, 133+/-27.5 cm/sec. The corresponding A/E ratios were 0.32+/-0.13, 0.48+/-0.18, 0.5+/-0.15, showing a rising trend. Treadmill evaluation at 6 months showed a mean 82% increase in heart rate after excising, and the SDNN and SDANN upon HRV Holter at 1 and 3 months postoperatively were 65.3+/-28.1/87.8+/-27.2 ms, and 60.0+/-24.1/83.4+/-25.7 ms, respectively, showing a predoinant autonomic recovery in the parasympathetic system(PSDNN = 0.01, PSDANN =0.015). CONCLUSION: The results of our data suggest that the current modification in the conventional Maze III Procedure was efective in enhancing the postoperative left atrial contractility.

One Stage Repair of Traumatic Ventricular Septal Defect and Mitral Regurgitation / 대한흉부외과학회지

After a penetrating thoracic injury early detection of intracardiac injury and early surgical repair when indicated are essential. A case presenting severe respiratory distress two weeks after a penetrating thoracic injury is reported. Transesophageal echocardiography showed massive pericardial effusion ventricular septal defect and mirtal regurgitation, The infundibular ventricular septal perforation was repaired using a Dacron patch the anterior mitral leaflet by interrupted sutures and the ruptured chordae of the posterior leaflet by a new chordae formation.

Open Heart Surgery Through other than Full Sternotomy in Adults / 대한흉부외과학회지

This study is to clarify the results of atrial septal defect (ASD) repair and mitral valve surgery through right anterolateral thoracotomy since 1989, and those of more generalized application of minimal invasive cardiac surgery since August 1997. We retrospectively analyzed the results of open heart surgery (OHS) through other than full sternotomy carried out until October 1997. There were 28 cases of OHS done through right anterolateral thoracotomy (17 cases of ASD, 4 cases of mitral valve repair, 6 cases of mitral valve replacement, and 1 redo mitral and tricuspid valve repalcement) which has demonstrated no surgical mortality or morbidity except only 1 case of reoperation for bleeding. During the period between August and October 1997, we performed near routine application of upper sternotomy or transverse sternotomy in aortic valve cases and routine application of minimal incision in cases with ASD and there was no evidence of early and late complications associated with this approach. We conclude that OHS with the use of minimal incisions is very safe, cosmetically excellent, and superior in terms of the amount of bleeding. The indication for minimal incision, therefore, should be extended afterwards.

Bleeding Tendency and Transfusion Feature after CABG / 대한흉부외과학회지

Postoperative autotransfusion is known as an effective method for blood conservation. We tried to examine whether the autotransfusion of shed mediastinal blood in patients with unstable angina would be valuable for reducing postoperative homologous transfusion by observing the hourly tendency of bleeding and transfusion. Between August and October, 1997, 26 patients with unstable angina underwent coronary arterial bypass surgery by a single surgeon at Asan Medical Center. In retrospective analysis, we found 90% of the patients received homologous transfusions and 85% of them were in the intensive care unit at the same day after operation. In many patients, the cause of transfusion was not anemia but volume replacement. Mean bleeding through the chest tubes was 340 cc for the first 5 hours and 69% (18 pts) showed more than 200 cc of bleeding, the amount generally considered as a initiating point for autotransfusion. Despite the adoption of multiple methods for blood conservation, 90% of the patients needed homologous transfusion. Moreover, many of them had received unnecessary transfusions. We conclude that some kind of blood for transfusion is needed during the immediate postoperative period, and the adoption of postoperative autotransfusion may help in reducing homologous transfusion.

Regression of Left Ventricular Hypertrophy after AVR in Aortic Valvular Stenosis / 대한흉부외과학회지

BACKGROUND: The regression of the left ventricular hypertrophy after prosthetic valve replacement in patients with aortic valvular stenosis is an important factor to determine the appropriateness of the replaced prosthetic valvular size. Methods: To assess the regression of myocardial hypertrophy, a retrospective analysis of Doppler echocardiographic and electrocardiographic data was undertaken before, soon after (7.5+/-2.1 day), and late after (10.7+/-1.8 months) surgery in 36 patients (22 males, 14 female, mean age 54+/-12.1 years, mean BSA 1.61+/-0.15m2) with predominant aortic valvular stenosis. The patients underwent St. Jude Medical aortic valve replacement. By the size of the valves used, the patients were divided into three groups (19, 21 and 23+). RESULTS: The mean body surface area (1.48+/-0.13) in the patients with the 19 mm valve was smaller than that in the other groups (1.63+/-0.12) (p<0.05). No significant changes of ejection fraction were detected in all groups over time. Left ventricular muscle mass index (gm/m2) was reduced significantly in the 21 and 23+ groups over time (p<0.05), but there were no significant changes in the 19 mm valve group. The electric voltage height on EKG at the period of late after surgery was reduced significantly in all groups (p<0.05). CONCLUSION: Despite clinical improvement, the LVH was not reduced significantly in 19 mm valve group. Thus we suggest that more attention and additional procedures such as annular enlargement should be taken in patients who will undergo the replacement of 19 mm prosthetic valve.

Effect of Magnesium Administration on Preventing Arrhythmias after Coronary Artery Bypass Graft / 대한흉부외과학회지

Arrhythmias are common after cardiac surgery and are multifactorial. Intravenous magnesium administration reduces the frequency of ventricular arrhythmias in patient with symptomatic heart failure or acute myocardial infarction. This study was designed to evaluate the role of magnesium in preventing PVCs (premature ventricular contractions) occurred frequently after coronary artery bypass graft (CABG). 50 consecutive patients were prospectively entered into a randomized trial to determine the efficacy of postoperative magnesium therapy on the incidence of cardiac arrhythmias after elective coronary artery bypass graft. The patients underwent coronary angiography, echocardiography, electrocardiography and clinical laboratory study preoperatively. Continuous electrocardiographic monitoring was done and magnesium level was checked 0, 3, 6, 12, 18, 24, 36, 48, 60 and 72 hours postoperatively. Study group of 25 patients were given 4g of magnesium continuously over the first 24 hours and then 2g/24hours from 25 to 72 hours. The clinical characteristics of both groups were similar (p<0.05). The preoperative mean serum magnesium concentration was similar in both study group, 1.59mg/dl and control group, 1.71mg/dl. The mean postoperative serum magnesium concentration in study group elevated significantly over postoperative 12hours through 36hours (p<0.05). The postoperative mean serum magnesium concentration in control group declined and remained significantly depressed over immediate postoperation through 72hours. The mean serum magnesium concentration was significantly greater in the study group compared with the control group over postoperative 3hours through 72hours (p<0.05). There was a significant decrease in the incidence of arrhythmias such as PVCs (p<0.01) which might jeopardize hemodynamics. There were no recognized adverse effects of magnesium Administration. In conclusion, prophylactic magnesium administration seems to lessen the incidence and severity of rrhythmias after coponary artery bypass graft.