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Background: In the present study we analyzed the in vivo performance of the 19-mm St. Jude Medical Hemodynamic Plus aortic prosthesis (19HP), evaluated the midterm performance of 19HP in the aortic position, and compared the implantability and hemodynamic characteristics of this valve with those of the 21-mm standard St. Jude Medical valve (21SD) in adult patients with aortic stenosis and a narrowed aortic annulus., Methods: From February 1994 to December 1999, 60 patients who underwent isolated aortic valve replacement with either the 19HP (n = 31) or the 21SD (n = 29) were studied. Comparison between the two models included analysis of early and late mortality and morbidity. Pre- and postoperative echocardiography was performed in all patients to evaluate and compare the hemodynamic performance of both prosthetic valves. The postoperative serum lactic dehydrogenase activity was measured in both groups of patients as an indicator of hemolysis., Results: The mean body surface area was 1.46 +/- 0.16 m2 in the 19HP group and 1.49 +/- 0.13 m2 in the 21SD group (p = 0.1577). Other than female dominance in the 19HP group, there was no statistically significant difference between the two groups in terms of preoperative variables (age, preoperative pressure gradients, and New York Heart Association functional class). The average postoperative peak pressure gradient was 23.3 +/- 10.5 mm Hg in the 19HP group and 27.9 +/- 9.9 mm Hg in the 21SD group (p = 0.0666). There was no hospital death in either group. Six-year follow-up was completed in both groups of patients. Late death occurred in 1 patient in the 19HP group (1.09% per patient-year). Actuarial survival at 6 years was 92.3% +/- 7.4% in the 19HP group, and 100% in the 21SD group (p = 0.33). The linearized complication rate was 1.09% per patient-year and 1.02% per patient-year for thromboembolism, and 1.09% per patient-year and 1.02% per patient-year for anticoagulant-related hemorrhage in the 19HP group and the 21SD group, respectively. Freedom from all complications at 6 years did not show any significant difference between the two groups (p = 0.54). Although left ventricular mass indices decreased significantly after aortic valve replacement in both groups (19HP group, p = 0.0002; 21SD group, p = 0.0006), there were no significant differences in the two indices between the groups after aortic valve replacement (p = 0.999). There was no significant difference in the lactic dehydrogenase level between the two groups (p = 0.4915)., Conclusions: In vivo hemodynamic performance of the 19HP valve as well as the early and intermediate clinical outcome up to 6 years was satisfactory and corresponded closely to that of the 21SD valve in adult patients. The 19-mm Hemodynamic Plus model can be recommended in patients with a measured 19-mm annulus and this valve will minimize the need for the aortic annular enlargement procedure.

According to the literature, the incidence of pannus formation with the St. Jude Medical prosthetic aortic valve has been reported at 0.03% and 0.14% (per patient-year), with no case report of St. Jude Medical prosthetic aortic valve malfunction due to pannus formation. Between 1980 and 1999, 1,186 patients underwent aortic valve replacement at our institute. We encountered 2 aortic valve malfunctions due to pannus formation, including the case of a 53-year-old woman who suffered a St. Jude medical aortic valve malfunction 13 years after the initial operation. A second aortic valve replacement was successful and the postoperative course was uneventful. The possibility of pannus formation on St. Jude Medical aortic valves must thus be considered and its mechanism clarified.

Recently, Bentall procedure is commonly performed for annuloaortic ectasia with aortic regurgitation or dissecting aneurysm. And the operative results are improving. In this study, we evaluated results of the St. Jude Medical (SJM) and Carbomedics (CM) valves which were used in this procedure. From 1979 to 1994, 87 SJM valves and 22 CM valves were implanted in the aortic position of Bentall procedure. Total follow-up was 528.6 years in the SJM group and 56.5 years in the CM group. According to the Kaplan-Meier actuarial method and the Cox-Mantel statistical analysis, actuarial survival, thromboembolism free rate, reoperation free rate, event free rate were not different between the SJM and CM groups. These results suggest that, current selection of the SJM and CM valves would be acceptable in Bentall procedure.

In triple valvular surgery, AVR+MVR+TVR or TVP, there are some problems around operation, because patients impaired cardiac function after a long history of the disease and some of them are reoperation cases. The sixty-five patients operated from May in 1980 to June in 1993 were examined. They were divided into two groups, group P and group R, depending upon procedure of tricuspid position. Group P consisted of 51 patients and group R of 14 patients. There were 22 (34%) reoperations. In group P, organic changes in tricuspid valve were mild, however in group R, there were commissural fusion in 8 patients, destruction of leaflet due to infectious endocarditis in one patient, and marked tricuspid annular dilatation in five patients. There was one early death in group R, no early death in group P. Actuarial survival rate at the 10th postoperative year was good as 81.6% in group P and 85.7% in group R. There were no significant differences in operative mortality and actuarial survival between group P and R.

A 53-year-old man, who had undergone tricuspid valve replacement with Hancock valve and direct closure of a ventricular septal defect when aged 34 years, was admitted with signs of right heart failure. Two-dimensional echocardiography showed bioprosthetic tricuspid valve malfunction with right atrial thrombus. He was treated by tricuspid valve replacement using a Hancock II valve and removal of the right atrial thrombus with remarkable improvement. Transesophageal echocardiography was the most useful method for recognizing the presence of right atrial thrombus and assessing its actual or potential hemodynamic effects.

Background and Aims of the Study: Surgical treatments for aortic valve disease in the presence of a small aortic annulus need appropriate indications for operative procedures and precise selection of valve prostheses. The objective of this study was to compare long term results after aortic annular enlargement with those after operation using a small valve prosthesis., Materials and Methods: Since 1980, 45 patients with small aortic annulus underwent operation at our institution. There were six men and 39 women, and their ages ranged from 16 to 69 with a mean of 45.6 years. Of these patients, 28 underwent aortic annular enlargements (Nicks' procedure in 13, Manouguian's in 12 and apico-aortic bypass in three patients) and 17 patients received standard aortic valve replacement with a small valve prosthesis (19 mm Standard St. Jude Medical). Mean follow up was 8.6 years in the enlargement group and 4.9 years in the standard group., Results: Early mortality was 3.6% (1/28) in the enlargement group and 5.9% (1/17) in the standard group (NS). The 10-year actuarial survival including all deaths was 85.7% in the enlargement group and 62.7% in the standard group (p < 0.10). The rate of freedom from reoperation at 10 years was 90.7% in the enlargement group and 93.8% in the standard group (NS). The 10-year freedom from all valve-related events was 81.0% in the enlargement group and 58.8% in the standard group (p < 0.05)., Conclusions: The above results suggest that long term mortality and morbidity after aortic annular enlargement might be superior to those after standard AVR with a small valve prosthesis.

Records from 99 patients who received the Delrin-disk model (Group D) of the Björk-Shiley (BS) prosthesis between December, 1971 and November, 1974 were reviewed and compared to those from 248 patients who received the Spherical-disk model BS between January, 1975 and June, 1981 (Group S). Complete follow-up was obtained in 98.8% of the patients. The follow-up was over 1302.3 patient-years (mean 13.2 years per patient) in Group D and 2967.5 patient-years (mean 12.0 years per patient) in Group S. Early mortality was not significantly different (Group D: 18.2%, Group S: 10.5%). Of 15 late deaths in Group D, 12 (60%) were valve related and of 58 late deaths in Group S, 34 (58.6%) were valve related. The survival proportion based on Kaplan-Meier analysis, and which included early deaths, was equivalent in both groups (Group D: 65.7% at 21 years, Group S: 64.8% at 18 years). The freedom from reoperation was 74.3% at 21 years for Group D and 95% at 18 years for Group S (p < 0.005). The incidence of prosthetic valve dysfunction in Group D was significantly higher than that in Group S during 15 years after insertion of the valve. The freedoms from thromboembolism and valve-related events were not significant in both groups. Gross examination of the explanted Delrin disk found wear indentations and excessive clearance between the disk and the prosthetic ring. Therefore, disk wear was the primary cause of prosthetic valve dysfunction for the Delrin model. These results suggest that patients with the Delrin-disk model of the Björk-Shiley prosthesis should receive close follow-up for structural integrity of the valve. Further, reoperation might be needed due to significant valve dysfunction in this group of patients.

A 69-year-old woman with combined valvular heart disease (mitral regurgitation and aortic regurgitation), ascending aortic aneurysm, and atrial fibrillation underwent double valve replacement (DVR) and, ascending aortic wall plication. The postoperative thrombo-test level was around 20%. The ST elevation on ECG (II, III, aVFm, V4 approximately V6) with chest pain were recognized on the 13 th postoperative day. She was diagnosed as having acute myocardial infarction, and percutaneous transluminal coronary recanalization was performed immediately. The coronary angiogram showed occlusion at the left anterior descending branch (#8). This lesion could be recanalized by 6,000 U plasminogen pro activator (pro-UK) administration. The cineangiogram on the 35th postoperative day, revealed complete recanalization of this occlusion. Several cases of acute myocardial infarction associated with valvular heart diseases has been reported previously in Japan. However, there has been no report, except for this case, demonstrating occlusion in the coronary artery after prosthetic replacement and successful PTCR. So, this case is the first report on that point.

An initial Bentall operation was performed on a patient aged 38 years with annuloaortic ectasia and aortic regurgitation. An echocardiogram and RI angiogram revealed a perigraft aortic aneurysm on the same patient aged 45 years. The aneurysm gradually developed and the maximum diameter reached 90 mm in size. The Redo-Bentall operation (Piehler modification) was successfully done once again on the same patient aged 56 years. The anastmosis between the right coronary orifice and the graft was detached on all sides. The anastmosis between the left coronary orifice and the graft was detached two thirds of all sides.

Intra-arterial aortoinfundibuloplasty is a newly developed aortic annular enlargement procedure in which, originally, the annulus was split anteriorly via the main pulmonary arteriotomy. An alternative method of aortoinfundibuloplasty was studied experimentally which creates spiral incisions on the free walls of both great arteries descending together into the aortopulmonary and infundibular septum via both commissures of right and left facing cusps of pulmonary and aortic valves. The valve prosthesis is implanted through this three-dimensional incision, followed by patch reconstruction. The ratio of annular augmentation was three sizes in two animals and four sizes in three animals. Immediate postoperative haemodynamics were satisfactory and there was no significant postoperative increase in systolic pressure gradient at the right ventricular outflow tract and in the right ventricular end-diastolic pressure. This alternative procedure could be applied to cases requiring radical annular enlargement and would give a wider view of both ventricular outflow tracts.

St. Jude Medical Hemodynamic plus bileaflet valve prosthesis (HP) was employed in 7 cases undergoing aortic valve replacement since December 1993. Echocardiographic evaluation of left ventricular dimension and transvalvular pressure gradient was performed in 5 cases with 19 HP before and after operation. Each data was compared with those of 21 cases having undergone aortic valve replacement with 19 mm Standard model (19 SD). There was no significant postoperative change in left ventricular end-diastolic dimension (50 +/- 4 mm to 44 +/- 8 mm; p = NS) and left ventricular end-systolic dimension (34 +/- 4 mm to 34 +/- 9 mm; p = NS) in 19 HP cases. However, left ventricular end-diastolic dimension (51 +/- 11 mm to 41 +/- 8 mm; p < 0.05) and left ventricular end-systolic dimension (35 +/- 12 mm to 28 +/- 9 mm; p < 0.05) decreased in 19 SD cases. Transvalvular systolic peak pressure gradient was reduced significantly in both groups (19 HP: 94 +/- 38 mmHg to 43 +/- 19 mmHg; p < 0.05, 19 SD: 73 +/- 49 mmHg to 33 +/- 14 mmHg; p < 0.05). Poor reduction of left ventricular volume and high residual systolic pressure gradient in patients with 19 HP might be due to relatively high incidence of stenotic lesion in original aortic valve disease. In some cases with these critical aortic stenosis, radical annular enlargement procedure would provide more fundamental release of left ventricular outflow tract stenosis rather than one size increase of effective orifice area by employing HPs. Structural examination demonstrated that 19 HP had the same outer diameter of sewing flange with identical orifice ring as 21 SD (24 mm) did, and 17 HP had that of 19 SD (22 mm). Therefore, precise attention is needed for application of SJM-19 HP in patients with small aortic annuli.

A 41-year-old man with aortic stenosis, mitral stenosis, and tricuspid regurgitation due to Maroteaux-Lamy syndrome underwent aortic and mitral valve replacement with tricuspid annuloplasty. The annular diameter of the aortic and mitral valves was extremely small. The valve prostheses were 19 mm in diameter in the aortic position and 25 mm in the mitral position. Histologically, the valves showed thickening and hyalinization of the collagen fibers, and the presence of foamy cells that contained a large quantity of pure acid mucopolysaccharide. On an echocardiographic examination performed 2 years after the surgery, the peak systolic gradient of the trans-aortic valve was 18 mmHg at rest, and 26 mmHg during exercise. Careful observation of the residual pressure gradient will be needed. The patient's present New York Heart Association (NYHA) status is grade I and he has returned to work.

Increases in pancreatic enzyme levels after cardiovascular surgery were studied, and their clinical characteristics evaluated. The subjects were 128 patients who had undergone cardiovascular surgery (65 patients after valve replacement, 32 after coronary bypass surgery and 31 after aortic artificial graft replacement). The pancreatic enzyme (serum amylase and lypase) levels were monitored serially before and after operation, and amylase fractions were measured at their peaks. The relationships of the peak lypase level with underlying cardiac diseases, background factors, factors related to surgery, factors related to the extracorporeal circulation, presence or absence of symptoms, and treatments were examined. The amylase level exhibited biphasic changes consisting of a peak in which salivary glands amylase (S type) was dominant and a peak in which pancreatic amylase (P type) was dominant. The second peak coincided with the peak lypase and occurred mostly 3 to 10 days after operation. The peak lypase level exceeded the normal range in 78% of all the patients. It exceeded 564 U/l, 4 times the normal value in 28% of the patients, many of whom were symptomatic. So, we recommended that these cases should be treated as "postoperative pancreatitis". A high peak lypase level showed a significant correlation with the history of gallbladder and pancreatic diseases and diabetes mellitus among the background factors and emergency operation and the use of IABP among the surgery-related factors.(ABSTRACT TRUNCATED AT 250 WORDS)

A 62-year-old woman was admitted with malfunction of the Hancock valve in mitral position. She had been suffering from gastroduodenal ulcer for about ten years. She couldn't take warfarin after 5 years later of the initial operation due to recurrent gastrointestinal bleeding. Judging from her age and renal dysfunction, we preferred mechanical valve to avoid the risks for the reoperation. After confirming the healed ulcer with administering omeprazole, we performed prosthetic valve replacement with SJM 29 M successfully. Postoperative course was uneventful and recurrence of the ulcer was not observed.

We have experienced a mitral valve plasty for mitral regurgitation combined with dilated cardiomyopathy in a 21-year-old male patient with Noonan's syndrome, who had suffered from recurrent congestive heart failure. In echocardiography, severe mitral regurgitation and prolapse of the posterior mitral leaflet were noted. The left ventricle was dilated and the function was severely deteriorated. The plasty consisted of plication of the prolapsed posterior leaflet and annuloplasty with Carpentier ring. Intraoperative biopsy of the myocardium of the left ventricle showed an appearance consisting with dilated cardiomyopathy. Postoperatively the mitral regurgitation disappeared and the patient returned to his ordinary life.

Although aortic valve replacement for aortic regurgitation relieves left ventricular volume overload, ventricular size often remains abnormal after operation, particularly in the setting of marked or prolonged preoperative left ventricular dysfunction. The aim of this study is to assess the relationship between the grade of ventricular arrhythmias before operation and the recovery of left ventricular function after aortic valve replacement. Between January 1980 and August 1993, 229 patients with pure aortic regurgitation underwent aortic valve replacement at our institution. In this group, 50 patients (21.8%) who showed left ventricular end-systolic volume index (LVESVI) of 150 ml/m2 or greater received 24-hour ambulatory electrocardiographic recordings before and after operation. According to the preoperative grade of ventricular arrhythmias, the patients were divided into three groups. Group A included 20 patients with severe and frequent ventricular premature beats (VPBs). Group B included nine patients with severe and non-frequent ventricular premature beats (VPBs). Group C included 21 patients with non-severe and non-frequent VPBs. Left ventricular end-systolic dimension (LVDs), end-diastolic dimension (LVDd) and fractional shortening (LVFS) were measured in each echocardiogram before, and one year and five years after operation. LVDd significantly decreased at one year after operation in all three groups. At one year after operation, LVDs significantly decreased in group B (42.0 +/- 7.6 mm) and group C (42.6 +/- 8.6 mm), while LVDs showed no significant change in Group A (55.4 +/- 11.1 mm). After five postoperative years, further significant decrease of LVDs was found in group C (32.4 +/- 7.1 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Newly-developed procedure for aortic annular enlargement was geometrically examined on its optimal annular augmentation. Valve prosthesis is accommodated by anterior annular split extending into aortopulmonary and infundibular septum and, eventually, protrudes into pulmonary valvular orifice in this procedure. Relationship between residual pulmonary valvular area (PVA) and aortic annular incremental radius (x) is given by: PVA = (r+x)2 [pi - 2 pi x/(r+x) + sin (2 pi x/(r+x))], where r is original aortic annular radius. Optimal aortic annular augmentation maximizing PVA and saving original PVA is 1.33 times and 1.70 times of original diameter respectively. Animal experiments employing six mongrel dogs demonstrated no significant increase of systolic peak pressure gradient in right ventricular outflow tract after the procedure standardized by this geometrical idea. Our procedure would bear radical enlargement of small aortic annulus.

Sudden death is a well known complication of aortic valve regurgitation and remains a common cause of late mortality after aortic valve replacement. Although malignant arrhythmias have been suggested as the cause of these outcome, there has been little information concerning the frequency and severity of ventricular arrhythmias in patients with aortic valve regurgitation. In order to evaluate the relation between the severity and/or frequency of ventricular arrhythmias and late postoperative results in patients with pure aortic valve regurgitation, 24-hour ambulatory electrocardiographic recordings were obtained before surgery in 107 patients without coronary artery disease. Grading of ventricular arrhythmias was based on a Lown method and compared with hemodynamic data. Ventricular premature beats were observed in 101 patients (94.4%) before operation. Multiformity was found in 10 patients (9.3%) couplets in 19 patients (17.8%) and ventricular tachycardia in 32 patients (29.9%). Patients with severe ventricular arrhythmias (Lown grade 3 or 4: 57.0%) had a higher left ventricular end systolic volume index (LVESVI) 153.1 +/- 76.4 ml/m2 vs 96.5 +/- 35.0 ml/m2 (p = 0.0001); a higher left ventricular end diastolic volume index (LVEDVI) 257.0 +/- 85.4 ml/m2 vs 206.5 +/- 58.3 ml/m2 (p = 0.0009); a lower left ventricular ejection fraction (LVEF) 43.4 +/- 12.5% vs 54.2 +/- 9.8% (p = 0.0001). LVESVI was not related to the severity of ventricular arrhythmias, but was significantly related to the frequency (p < 0.05). All patients with late death were belonging to Lown grade 3 or 4 in severity and more than 30 beats per hour in frequency (28.6%). This study indicates that ventricular arrhythmias are common in patients with aortic valve regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

A 23-year-old female was undergone the modified Bentall's operation for the prosthetic valve malfunction with annuloarotic ectasia due to aortitis syndrome. For she was in active inflammatory phase at the first admission to our hospital, the glucocorticoid steroid therapy was started to control the inflammation. After the good control was induced, the re-operation was done. In the operation, the prosthetic valve was detached from the annular ring and the motion was restricted by small thrombus and the remnant of right coronary cusp, and the right coronary orifice was not noticed. The right coronary artery was not able to be reconstructed, and slightly ischemic change was occurred postoperatively. She was treated by glucocorticoid steroid also in the postoperative period. Her postoperative course has been uneventful of three years.

Case histories of 39 patients who underwent tricuspid valve replacement with the St. Jude Medical prosthesis between June 1979 and August 1992 were reviewed in March 1993. The average patient age at the time of the operation was 46 +/- 11 years (range from 17 to 68 years). Concomitant mitral and/or aortic valve replacements were performed in 30 patients. All patients were given warfarin to maintain thrombotest between 10% to 25%. This number was between 2.8 to 1.6 times the control value in the International Normalized Ratio of prothrombin time. Three operative deaths occurred (7.7%). Among six late deaths, two patients died suddenly of unknown causes, and the remaining patient deaths were not valve-related. The actuarial survival rate at 14 years was 54.7%. Valve thrombosis occurred in one patient and was successfully treated with intravenous urokinase. This was the only valve-related complication (0.67%/patient-year). No reoperations were necessary in the tricuspid position. In conclusion, the St. Jude Medical valve is our choice of prosthesis for tricuspid valve replacement in adult patients who can receive proper anticoagulation therapy.

According to STS/AATS guidelines 1988, we compared the long-term results after cardiac valve replacement (ReAVR 26, ReMVR 127, ReDVR 35, ReTVR 2, total 190 patients) with those after initial valve replacement (AVR 760, MVR 1, 001, DVR 431, TVR 22, total 2,214 patients). Actuarial survival (AS), reoperation free (RF) and freedom from all valve-related events (EF) at the 10th postoperative year were 74.6%, 100%, 70.1% after ReAVR, 84.2%. 97.8%, 75.8% after AVR, 82.9%, 91.4%, 75.8% after ReMVR, 86.5%, 91.7%, 70.7% after MVR. 78.4%, 92.9%, 63.2% after ReDVR, 82.8%, 95.6%, 73.8% after DVR, respectively. There was no significant difference of AS, RF and EF between ReVR and initial VR in any valve position. These results justify our current strategy of cardiac valve re-replacement.

Successful reconstruction of the aortic annulus for perivalvular leak following combined valve replacement was performed in two patients, 6 and 7 years postoperatively, using Manouguian's operation. A fistula was seen at the junction of the aortic annulus and the superior or inferior margin of the patch used for enlargement. This fistula was closed from both sides; from the left atrium with reinforced Teflon pledgets and from the aorta using a patch. Successful reconstruction of the aortic annulus was made, and no regurgitation was seen after the operation.

Since July 1978, 1,284 patients have received the St. Jude Medical prosthesis (425 aortic, 636 mitral, and 223 double aortic-mitral), and the results in these patients were reviewed according to guidelines of the Society of Thoracic Surgeons. Follow-up was complete in 98%. Of 80 late deaths, 29% were valve related. The actuarial survival rate, including operative deaths, at 12 years was 81.7% and 87.1%, respectively, for aortic and mitral valve replacement, and it was 82.6% at 11 years after double valve replacement. All patients were anticoagulated with warfarin to maintain the thrombotest value between 10% and 25%, which is equivalent to between 2.8 and 1.6 times the control according to the international normalized ratio of the prothrombin time. The linearized rate of complication for aortic, mitral, and double valve replacement, respectively (expressed as the percent per patient-year), was as follows: structural deterioration, 0; non-structural dysfunction, 0.16, 0.30, and 0.20; valve thrombosis, 0.05, 0.09, and 0; thromboembolism, 1.35, 1.63, and 0.79; anticoagulant-related hemorrhage, 0.10, 0.18, and 0.10; and prosthetic valve endocarditis, 0.21, 0.06, and 0.20. Reoperation was performed in 16 patients. The freedom from reoperation rate at 12 years was 99.5% and 98.0% for aortic and mitral valve replacement, respectively, and it was 99.1% at 11 years for double valve replacement. Thus, during the 12-year follow-up in patient who received the St. Jude Medical prosthesis, the valve performed satisfactorily and with an acceptable risk of late complication even though patients were anticoagulated using a lower dose of warfarin.

Although a high incidence of strut fracture of the Björk-Shiley convexo-concave (C-C) valve prosthesis has been reported, it is still controversial whether the prosthesis functioning normally should be replaced electively. To clarify our policy for this issue, we reviewed 28 patients who had undergone mitral valve replacement with a C-C valve prosthesis, and evaluated long-term results according to STS guidelines. The incidence of valve-related complications expressed as % patient-year were; structural deterioration 0.30, nonstructural dysfunction 0.30, thromboembolism 1.20. There were no thrombosed valves, anticoagulant-related hemorrhage or prosthetic valve endocarditis. The actuarial free rate after valve replacement with the C-C at 10 years, constructed by the Kaplan-Meier method, were compared with those with St. Jude Medical (SJM) valve prosthesis. (1) Actuarial survival: 77.9 vs 87.3 (NS), (2) Reoperation-free: 91.6 vs 98.0 (p < 0.05), (3) thromboembolism-free: 83.7 vs 83.9 (NS), (4) Event-free (hospital death+reoperation+valve-related complications: 71.2 vs 77.7 (NS). The long-term results with the C-C were compatible to those with a SJM valve prosthesis. However, if a strut fracture occurs, it is very difficult to save the patient's life. The hospital mortality of re-replacement of valve prosthesis during the last 10 years, at our institute, was 2.6%, which is almost equal to the cumulative risk of strut fracture of the C-C valve after 10 years (3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

For surgical management of Ebstein's anomaly, a new technique of tricuspid valve replacement on the true annulus, avoiding injury to the conduction system, has been developed. At operation, the valve fixation sutures are placed around the true annulus except for a part of Koch's triangle. A 3 x 3 cm xenograft patch is sutured to cover the atrioventricular node and bundle of His. The remainder of the valve fixation sutures in Koch's triangle are placed only on the patch to prevent conduction injury, and the valve fixation annulus is completed. This new technique has been applied to three patients and has preserved atrioventricular conductivity well in all cases. It is concluded that this procedure of tricuspid replacement on the true annulus can be safely applied and is remarkably effective in preventing atrioventricular conduction disturbance.

To develop an optimal prosthesis for use in the tricuspid valve, we determined the change in cardiac performance associated with the change in shape of the anulus of the tricuspid valve using a metal ring of variable flat ratio (defined as the long/short axis). In experiment I in an isolated autoperfusion model with six dogs, the left ventricular stroke work under a constant left atrial pressure of 7 mm Hg were, in grams per beat per minute, 11.88 +/- 0.52 with a flat ratio of 1.0, 11.88 +/- 0.70 with a flat ratio of 1.3, 16.23 +/- 0.61 with a flat ratio of 1.6, and 11.22 +/- 0.38 with a flat ratio of 2.3 (mean +/- standard error of the mean). The volume was significantly higher with a flat ratio of 1.6 than with the other ratios (p < 0.05). In experiment II with six dogs in vivo, the blood flow of the pulmonary trunk artery was 0.57 +/- 0.03 L/min with a flat ratio of 1.0, 0.66 +/- 0.03 L/min with a flat ratio of 1.6, and 0.58 +/- 0.03 L/min with a flat ratio of 2.3; the flow was significantly larger with a ratio of 1.6 than with the other ratios (p < 0.05). Right ventriculography was performed in five dogs. The percentage of radial shortening of the apex close to the acute margin was 19.4% +/- 3.1% with a flat ratio of 1.0 and 49.2% +/- 5.1% with a flat ratio of 1.6 (p < 0.05). In conclusion, the best hemodynamic results were obtained with a flat ratio of 1.6, which showed more advantageous hemodynamics than do the ratios of conventional circular prostheses.

A 49-year-old man who had undergone AVR entered our hospital with congestive heart failure and continuing slight fever. By cardiac imaging, he was diagnosed prosthetic valve endocarditis with periannular pseudoaneurysm and perivalvular leakage. He underwent a new translocation method using a composite valve (a prosthetic valve directly sutured a ring prosthesis, which was separated from an intraluminal ringed graft). Post operative course was uneventful. He recovered well after the operation.

A new method for prosthetic valve replacement in a small aortic annulus is described. An anatomical examination showed that the intra-arterial approach via the main pulmonary artery made it feasible to incise the aortopulmonary septum at the middle point of both coronary ostia and also to relieve left ventricular outflow tract obstruction with a two-dimensional patch. The pressure study in three mongrel dogs demonstrated that 6-mm augmentation of the host aortic annulus with this procedure made no significant difference in the pressure gradient between the right ventricle and the main pulmonary artery before and after operation. The right ventricular end-diastolic pressure did not show any significant change with respect to hemodynamics. It is expected from these results that our procedure could be used for the treatment of various types of left ventricular outflow tract stenosis without affecting the hemodynamics and, especially, right ventricular function.

In the surgical treatment for active infective endocarditis (IE), perivalvular leakage is the most severe complication. We had a 42-year-old man who had active IE and a giant vegetation in the aortic valve, and a small mycotic aneurysm in the left ventricular outflow tract. Other operative observations included slight redness and a decrease in the reflex of the annular endocardium. We made a patch closure of the mycotic aneurysm, and aortic valve replacement using the Teflon felt reinforcing method. In the postoperative course, he had a pacemaker implantation with complete AV block. Postoperative pathological examination revealed inflammatory cells and plasma infiltration, and edematous change of the interstitial tissue around the cusp surface and annular side of the resected valve. These pathological changes could explain the redness and the decrease in the reflex of the annular endocardium. The edematous changes of the annular tissue might be the cause of postoperative perivalvular leakage. Reinforcement of the prosthetic valve with Teflon felt might be a useful method to prevent perivalvular leakage. There is, however, the possibility of acceleration or elongation of infective endocarditis. In our experiences of the surgical treatment for active IE, we performed valve replacement using Teflon felt in 6 patients, and not using in 27 patients. The mean period until CRP had been normalized was no significant difference between both groups (mean days using Teflon felt were 63.5 days, and not using were 75 days).(ABSTRACT TRUNCATED AT 250 WORDS)

A 66-year-old man who had undergone MVR using a ST. Jude Medical valve entered the hospital with acute heart failure and cardiogenic shock 3 months after surgery. He had had a symptom of petechiae due to macrogloburinemia after initial MVR and had been in the poor control of anticoagulation therapy because of presence of petechiae. He was diagnosed as prosthetic valve thrombosis using echocardiography and underwent emergency re-MVR using a Central Open Bioprosthesis (COB) which was developed by our department. He was doing well 8 month after re-MVR. Selection of prosthetic valve should be performed carefully in the patient with hemorrhagic disease, and careful observation and proper anticoagulant therapy should be carried out after valve replacement.

A previously healthy young man sustained a chest injury. During hospital admission following the accident, he exhibited progressive deterioration in blood gases. The chest X-ray showed pulmonary venous congestion. Positive pressure ventilation was required with a tentative diagnosis of respiratory distress syndrome. However, he remained in NYHA class IV. Trans-esophageal cross-sectional echocardiography showed prolapse of the anterior mitral leaflet with papillary muscle rupture. Mitral valve replacement was performed successfully.

A bioprosthetic cardiac valve cross-linked with a glycerol polyglycidyl ether polyepoxy compound (PC) was developed in order to reduce calcification and degeneration, which often occurs in bioprosthetic cardiac valves. Aortic valves harvested from dogs were treated with PC (PC valve). Right ventricle (RV)-pulmonary artery (PA) bypasses were placed in 12 dogs with PC-valved conduits, and the main PA was ligated. X-ray right ventriculography at 36 days (1 dog) and 37 days (1 dog) revealed an excellent open/close performance of the PC valve, and there was no visible thrombus in the valve. In our basic study, PC treated collagen gel disks implanted in the subcutaneous layer of growing rats showed remarkably less calcium deposition than did those treated with glutaraldehyde (GA). Biologic materials cross-linked with PC maintain their pliability, and become more hydrophilic and more hydrated than those cross-linked with GA. The hydrophilicity and hydration provide sufficient antithrombogenicity and a suitable environment for metabolism in the tissue fluid which contains oxygen, nutritive substances, and electrolytes, leading to inhibition of material degeneration. Therefore, PC valves are expected to show good valve function, sufficient antithrombogenicity, and excellent durability with less calcification, when compared to GA treated valves.

Two cases of iatrogenic left main coronary artery stenosis (ICOS) following aortic valve replacement (AVR) are documented. The first patient began to have chest pain due to myocardial ischemia 7 months after AVR. Angiographically, the ostium of her left coronary artery was severely stenotic. She refused coronary bypass grafting. She died of myocardial infarction due to ICOS, 23 months after AVR. Histologically, a loose cellular connective tissue was found around the stenotic coronary arterial lumen. The other patient had chest pain 4 months after aortic and mitral valve replacement. The ICOS was diagnosed angiographically. After she had coronary bypass grafting, she was free from myocardial ischemic symptoms. The onset of myocardial ischemic symptoms in the first six months after AVR is highly suggestive of ICOS, and urgent coronary angiography is recommended and, if proximal stenosis of the coronary arteries is diagnosed, coronary bypass grafting should be performed.

During the past 15 years, we followed 21 patients with prosthetic heart valves who experienced a total of 24 pregnancies at mean age of 31.3 +/- 3.6 years. The course of these patients and their pregnancies were reviewed to evaluate the problems associated with prosthetic heart valves and anticoagulation. Among the 21 patients, the aortic valve (AV) had been replaced in 10 (12 pregnancies), the mitral valve (MV) in nine (10 pregnancies), AV + MV in one (one pregnancy), and the tricuspid valve (TV) in one (one pregnancy). The implanted prosthetic valves were mechanical type in 16 cases (Björk-Shiley 15, Starr-Edwards 1) and bioprosthetic type in six (Hancock 5, Ionescu-Shiley 1). With the exception of one case of intra-uterine fetal death probably related with warfarin therapy, all the patients with bioprosthetic valves underwent successful deliveries. Anticoagulant therapy was employed for 11 pregnancies; warfarin for 10 and subcutaneous heparin for one. No anticoagulant therapy was performed for 13 pregnancies. Ten of the 21 mothers had atrial fibrillation. Eighteen pregnancies (67%) culminated in uneventful deliveries for both mothers and infants. Three mothers (13%) died of thromboembolic complications; two of cerebrovascular accidents and one of acute heart failure caused by thrombus on the replaced valve. All of them had Björk-Shiley valves. Oral warfarin was administered in one of the three, heparin in one and no anticoagulant in the remaining one. Massive maternal bleeding occurred in two cases (8%). There were three cases (12%) of intra-uterine fetal death which were caused by intracranial hemorrhages.(ABSTRACT TRUNCATED AT 250 WORDS)

This study was undertaken to compare the usefulness of left ventriculography versus root aortography as a means of assessing the aortic annular size in 75 patients with a narrow aortic anulus. These patients were divided into two groups: Group I consisted of 57 patients undergoing standard aortic valve replacement with a 21 mm prosthesis and Group II consisted of 18 patients undergoing modified aortic valve replacement with the aid of an anulus-enlarging procedure or an apico-aortic conduit. In Group I, left ventriculography gave 23.2 +/- 1.8 mm (mean +/- standard deviation), whereas the aortography method showed 22.4 +/- 2.7 mm (p less than 0.05). Those values of 20 mm or less were regarded as imperfect measurements; inaccurate results were more frequent in the aortography method (16 cases; 28%) than in the left ventriculography method (only two cases; 3.5%), with significant difference (p less than 0.025%). In Group II, there was no significant difference in respective values determined by the two different methods; 18.7 +/- 3.0 mm, with a range from 13 to 23 mm in the left ventriculography method, and 19.9 +/- 3.1 mm, with a range from 14 to 24 mm, in the aortography method (p greater than 0.2). Imperfect measurement by the aortography method tended to occur when the cusp base was severely deformed. The results indicated that left ventriculography was more reliable than root aortography for estimating the size of the aortic anulus.

In an effort to normalize the dynamic leaflet behavior of a porcine bioprosthesis, an experimental attempt was made to treat a tissue heart valve with 0.625% glutaraldehyde in the open position ("open-type valve"). Eighteen open-type valves, having fixed openings of various sizes, were examined with our pulse simulators. Eight closed-type valves, which were treated in the closed position, were studied for comparison. The results showed that closed-type valve tended to offer an immobile cusp at a low flow state; at a pump pressure of 90 mm Hg in a pulsatile flow or under steady flows of no more than 10 L/min. By contrast, the open-type valve showed the symmetric cusps opening with circular orifices at any given flow rates. Analysis of the pressure loss coefficient revealed that the leaflets prepared in the open position produced only a minimal impediment to the forward flow. One half of the anatomic orifice of a valve was considered to be the optimal size for the fixed opening. It is concluded that open position fixation is expected to provide the bioprosthesis with improved fatigue durability in patients with low cardiac output syndrome and in small children.

Replacement of the aortic valve and the entire ascending aorta (modified Bentall's technique) was performed in 11 patients with annulo-aortic ectasia. Nine patients are alive and well postoperatively. In comparison with our previous surgical technique, by which the aortic root was left remaining without removal, the new technique required less bypass time, including less coronary perfusion time and less amount of intraoperative bleeding than the cases handled by the previous technique, whereas amount of postoperative bleeding in both groups was not significantly different. Details of the new technique were described and the advantages of this technique are security of intraoperative hemostasis as well as shortened operation time. The Björk-Shiley tilting disc prosthesis was really convenient for this surgical technique because of its low profil architecture, and also this prosthesis gives excellent postoperative results in combination with the new surgical technique.

St. Jude Medical (SJM) valve replacement in 995 patients with a cumurative follow-up period of 2,730 patient-years was compared with the Björk-Shiley (BS) valve replacement in 406 patients, who had followed up for 3,779 patient-years (pt-yr). The overall survival rates of aortic, mitral, and double valve replacement with SJM (and BS) at 10 years were 60.6% (80.0%), 89.6% (81.9%), 90.3% (73.9%), respectively. The linealized incidences of thromboembolism, valve thrombosis, prosthetic valve endocarditis, anticoagulation-related hemorrhage, significant hemolysis, and structural failure in SJM (and BS) were as follows: 1.32%/pt-yr (0.82%/pt-yr), 0.11%/pt-yr (0.21%/pt-yr), 0.18%/pt-yr (0.08%/pt-yr), 0.04%/pt-yr (0.24%/pt-yr), 0.18%/pt-yr (0.13%/pt-yr), and 0%/pt-yr (0.05%/pt-yr), respectively. Reoperation (explant and re-replacement or suture repair) was required in 10 SJM patients (0.37%/pt-yr) and in 14 BS cases (0.37%/pt-yr). Actuarially over 97% of patients were free of valve-related mortality at 10 years in both groups. From these results we conclude that both SJM and BS valves are equally excellent cardiac valve prosthesis. Considering the better hemodynamic characteristics and technical feasibility, we have thus far adopted SJM, rather than BS, as a first prosthesis of choice.

To evaluate the early and late results of mitral valve replacement and reconstruction for mitral insufficiency due to ruptured chordae tendineae respectively, 74 consecutive cases were analyzed. Fifty-five (74.3%) of the patients were men, and the mean age was 48 +/- 12 years old (range 16 to 76). The causes of the mitral disease were idiopathic in 50 (67.6%), rheumatic in 7 (9.4%) and infective endocarditis in 11 (14.9%) patients. In idiopathic 50 cases, 24 had mitral valve prolapse and 16 had both mitral valve prolapse and hypertension. Forty-one (55.4%) of the patients were in NYHA functional class III or IV preoperatively. Thirty (40.5%) cases underwent surgery within one year after their initial symptoms of heart failure onsets including six emergency operation cases due to uncontrollable acute lung edema. Chordae to anterior mitral leaflet were ruptured in 31 (a5, m16, p10)[41%] patients, to the posterior mitral leaflet in 45 (a4, m23, p18)[59%], and to both leaflets in one patient. Mitral valve replacement was performed in 68 patients (91.9%) and 6 patients (8.1%) underwent mitral valve repairs. Twenty cases underwent associated procedures that included tricuspid valve annuloplasty in 8, aortic valve replacement in 5 and myocardial revascularization in 4 cases. There were two operative deaths (2.4%); both occurred after replacement, left ventricular rupture in one and DIC in one. Mean follow-up period was 4.5 years (range 1 to 17) in 67 cases. There were four late deaths; all occurred after replacement. However five patients sustained mild mitral insufficiency after mitral valve repair including one that became worse of regurgitation three years after isolated Kay's annuloplasty, there were no cases that had needed reoperation and no late death after reconstruction. Left ventricular function and pulmonary arterial pressure were almost normalized in more than 90% cases postoperatively. Our data indicated that mitral valve reconstruction (McGoon's plus Kay's method as standardized maneuver) was the procedure of choice for selected patients with mitral insufficiency owing to ruptured chordae tendineae to the posterior mitral leaflet, including more limited patients with ruptured chordae to the anterior mitral leaflet.

The influence of inward bending of the stent posts on bioprosthetic valve function was assessed in a hydromechanical simulation of the left heart. A Carpentier-Edwards mitral xenograft (31 mm) and an aortic xenograft (27 mm) were used. Valve function was evaluated before and after the stent posts were bent inward 15 degrees by suture constriction of the tops of the three posts. To evaluate the effects of the stent-post deformity on valve performance, the mean transvalvular pressure drop during steady flow, the bioprosthetic valve orifice area, and the maximum valve opening and closing speeds during pulsatile flow were measured using an area meter. Steady-flow data showed identical transvalvular pressure drops, and no significant difference in valve performance was detected in the pulsatile-flow study under the two experimental conditions (i.e., normal valve and deformed valve). We conclude that a 15-degree inward bending of the stent posts does not appreciably affect valve function in vitro.