Clinical application history of prosthetic heart valves has been over five decades, and mechanical heart valves have satisfactory clinical outcomes for surgical treatment of valvular heart disease. The development history of mechanical heart valves experienced from the first generation of ball valves and caged disc valves to the second generation of single tilting disc valve, and to the third generation of bileaflet valves. In 1960， ball valve was first used for heart valve replacement in abroad. In 1963， China-made ball valve was also produced and used in clinical practice. In 1969， the second generation of single tilting disc valve was developed in abroad. In 1978， China-made single tilting disc valve was produced and widely used in clinical practice with satisfactory clinical outcomes. Since 1980 when it was first produced， bileaflet valve has taken the place of above 2 types of valves for its excellent performance, and become the mainstream product all over the world. Currently, the development of China-made bileaflet valves has lagged behind， and domestic mechanical heart valve market has almost been monopolized by foreign bileaflet valve products. Therefore, the development of ideal China-made mechanical heart valve deserves further research.
Abstract： Objective To summarize our operative experiences of cardiac reoperation after mechanical valve prosthesis replacement and investigate the causes of reoperation and the perioperative techniques and operation methods. Methods From January 2001 to December 2008, we performed reoperation on 105 patients (59 males and 46 females, aged 50.2±10.6 years old) who had undergone mechanical valve prosthesis replacement. Among the patients, there were 31 cases of mitral valvular replacement (+ tricuspid valvular plasticity), 38 cases of aortic valvular replacement (+ tricuspid valvular plasticity), 11 cases of Bentall procedure, 7 cases of mitral and aortic bivalvular replacement (+tricuspid valvular plasticity), 8 cases of tricuspid valvular replacement, 6 cases of repairing of prosthetic leakage, and 4 others cases. The time interval between two operations was 3 months to 18 years (46.3 ±31.9 months). Before reoperation, the cardiac function (NYHA) of the patients was class Ⅱ in 27 patients, class Ⅲ in 53 patients, and class Ⅳ in 25 patients. Results There were 6 hospital deaths with a mortality of 5.71%(6/105). All others recovered to NYHA class ⅠⅡ. The causes of mortality included 1 case of multiple organ failure, 1 case of low cardiac output after operation, 1 case of aortic pseudoaneurysm rupture, 1 case of severe infection due to brain complication and 2 cases of prosthetic valve endocarditis (PVE). The causes for cardiac reoperation after mechanical valve prosthesis replacement were 67 cases of prosthetic leakage (63.80%), 16 cases of PVE (15.23%), 14 cases of prosthetic thrombosis (13.33%) and 8 cases of other valvular anomalies. Followup was done for 11 to 107 months, which showed two cases late deaths of cardiac arrest and cerebral hemorrhage. Conclusion Patients who have received mechanical valve prosthesis replacement may undergo cardiac reoperation due to paravalvular prosthetic leakage, paravalvular endocarditis, and prosthetic thrombosis. The keys to a successful cardiac reoperation include appropriate preoperative preparations, operational timing, and suitable choosing of cardiopulmonary bypass and operational skills.
Objective To analyze the causes of mechanical valve dysfunction and the reconstructive surgical procedure, and summarize the treatment experiences in perioperative period. Methods From October 1996 to October 2008, 12 276 patients underwent mechanical valve replacement in Fu Wai Hospital. Thirtytwo of them were reoperated because of mechanical valve dysfunction. There were 12 male and 20 female aged from 1661 years with an average age of 43.8 years. All the reoperations were performed under hypothermic cardiopulmonary bypass, including 16 mitral valve replacement, 8 aortic valve replacement, 3 aortic and mitral valve replacement, 3 tricuspid valve replacement, 2 disc rotation and 1 excision of an excessive knot. There were 13 emergency operation and 19 elective operation. Results The time of ventilator assistant respiration was 5.1-144.0 hours.The median time was 15 hours and tracheostomy was needed in 2 cases. Six patients died after reoperations, the mortality rate was 18.8%(6/32). Three died of low cardiac output syndrome, 2 died of multiple organ failure and 1 died of malignant arrhythmia. Three cases had complications. There were 1 infective endocarditis, 1 intractable hiccup and 1 incisional infection, respectively. They were all cured and discharged. Conclusion Prosthetic valve dysfunction is one of the serious complications after mechanical valve replacement. Early detection, early diagnosis and early reoperation are needed.
Objective To evaluate the early and middlelongterm clinical results of tricuspid valve replacement (TVR) and compare the relative merit between bioprothesis and mechanical valve in tricuspid position，so as to elevate the operative effect. Methods The data of 128 TVR from April 1992 to February 2008 in An Zhen Hospital were retrospectively reviewed， and classified into mechanical prosthesis group（n=89）and bioprothesis group（n=39）according to the prosthesis used in the first procedure. Kaplan-Meier curve were estimated to evaluate the midlong term survival rate and events incidence related to prosthesis（including thrombosis, embolism and bleeding related to prosthesis and the prosthesis deterioration）. Multivariate binary logistic regressions were used to evaluate the independent risk factor for early and late death. Results There were 19 early deaths( 14.84%). With the followup of 4.93±2.92 years, there were 11 late deaths(10.7%). According to the Kaplan-Meier curve, the 10year actuarial survival rate for the bioprothesis group and mechanical prosthesis group were 65.6%±17.4% and 68.7%±10.8% respectively(Log-rank test,χ2=0.74，P=0.390). Freedom from prosthesis-related embolism at 5 years for the bioprothesis group and mechanical prosthesis group were 92.3%±7.4% and 87.1%±4.6% respectively(Log-rank test, χ2=0.962，P=0.327). Freedom from anticoagulationrelated bleeding at 10 years for the bioprothesis group and mechanical prosthesis group were 100% and 79.7%±9.7% respectively(Log-rank test, χ2=1.483，P= 0.223). There were 9 TVR reoperation, freedom from reoperation at 7 years for the bioprothesis group was 71.1%±18.0%, and freedom from reoperation at 10 years for the mechanical prosthesis group was 78.8%±10.2% (Log-rank test, χ2=2.76，P=0.096). Binary logistic regression revealed that the redo procedure and ascites were independent risk factors for early death, whereas ascites, heart function of New York Heart Association class Ⅲ/Ⅳ and multi valve replacement were independent risk factors for late death.Conclusion To lower the operative mortality and late mortality and morbidity, TVR should be adopted prior to the deterioration of right heart function, and bioprothesis valve has similar early and middlelong term clinical effect with mechanical valve in tricuspid position.
Abstract: Objective To summarize the clinical experience of 13 patients of tricuspid valve replacement and to investigate the indication and method. Methods From January 1994 to December 2005, the clinical datum of the thirteen patients suffering from tricuspid valve disease were reviewed, including rheumatic heart disease 6 cases, congenital heart disease 3 cases, infective endocarditis 3 cases and right ventricular tumor 1 case. All the cases underwent tricuspid valve replacement. Results Two reoperative rheumatic heart disease patients died early after operation and their cardiac function was New York Heart Association (NYHA) class Ⅳ before operation. The followup interval was 3 months to 12 years in 11 cases. There were 2 late death, one died of recurrence of infective endocarditis, and another died of the recurrence of the tumor. One Ebstein anomaly case’s NYHA functional recovered to class Ⅲ, eight cases’s recovered to NYHA classⅠ-Ⅱ. Conclusion The tricuspid valve disease may be a secondary lesion from many causes. Indication of tricuspid valve replacement must be strictly commanded. The late results of tricuspid valve mechanical prostheses replacement is satisfactory.
Objective To analyze the medium-and long-term r esults of tricuspid valve replacement(TVR), to summarize the experience in opera tive therapy for tricuspid valve disease. Methods From January 1998 to May 2006, sixty seven patients had undergone TVR. The etiology was rheumatic disease in 25 cases, congenital disease in 37 cases, degenerative disease in 1 case, infective endocarditis in 3 cases, a nd cardiac tumor in 1 case. All operations were performed under general anesthes i a and by cardiopulmonary bypass. Bioprostheses was replaced in 28 patients, whil e mechanical valve was replaced in 39 patients. Associated procedure included mi tral valve replacement in 13 cases, mitral valve replacement and aortic valve replac ement in 12 cases, repair of ventricular septal defect in 1 case, repair of atri al septal defect in 1 case, and radioablation of atrial fibrillation in 3 case s. Results The operative mortality was 11.94% (8/67)，among these patients , 6 cases died of serious heart failure,1 case died of ventricular fibrillation, 1 case died of multi organ failure. During follow-up, 1 patient died of biopro thesis dysfunction 1 year after the operation, 1 patient died of cerebral emboli s m 6 years after the operation. Through statistical analysis, it showed that the mortality of TVR in rheumatic tricuspid valve disease was higher than that in co ngenital tricuspid valve disease ［5.56%（2/36）vs. 24.00% (6/25); χ2=4.425 , P=0.036］; the mortality in second time operation was higher than that in first time operation ［30.00%（3/10）vs. 8.77% (5/57);χ2=3.646，P=0.033 ］; while there was no significant difference in immediate and long-term result s with different choice of bioprosthetic or mechanical valve in TVR (χ2=0.002 , P=0.961). Conclusion Operative an d follow-up mortality is high in the TVR, valve replac ement is the last selection for the treatment of serious tricuspid disease, appr opriate operative technique and perioperative therapy is the key for success o f the operation.
Objective To compare the result of different anticoagulation methods after mechanical heart valve replacement in order to optimize the early-stage anticoagulation therapy. Methods Eighty-six patients with mechanical valve replacement were divided into four groups according to different anticoagulation methods, warfarin group 1 ： warfarin was given from the 1st day after operation; warfarin group 2： warfarin was given from the 2nd day after operation; dipyridamole group： dipyridamole was given for two days from the 1st day after operation, and usage of warfarin from the 2nd day after operation ; fraxiparine group ： fraxiparine was given for two days from the 1st day after operation, and warfarin was given from the 2nd day after operation. Complication and post-operative death were observed. The value of porthrombin time （PT）, international normal ratio （INR）, and blood clotting factor Ⅱ , Ⅶ etc. were monitored respectively at the day before operation, the day of operation and the 3rd, 5th day after operation. Results All the results of 4 groups have met the anticoagulation requirement on the 5th day after operation （INR 1.5-2. 0）, and no hemorrhage, embolism and death occurred. In warfarin group 1, level of blood clotting factor Ⅱ , Ⅶ decreased, and level of PT, INR rose continuously, level of INR was 2.13±1.14 at the 5th day after operation, 1NR of 7 cases more than 2.0 in warfarin group 1 which was significant statistically compare with the other 3 groups（P〈0. 01）. Conclusions To adopt warfarin with the maintainable dose from the 2nd day after mechanical valve replacement could simplify anticoagulation method, with no increased risk of post-operative complications, such as hemorrhage and embolism. There is no need for additional anticoagulation methods.
The body is at a hypo-coagulation status after the heart mechanic valve prosthesis replacement operation, and the incidence of anticoagulation complications is rather high because of that administration of warfarin may result in “anticoagulation vacuum” at an early stage. Moreover, the necessary application of other anticoagulation methods assisting the employment of warfarin have still not been scientifically normalized. Blood coagulation factor Ⅱ,Ⅶ, prothrombin fragment1+2 (F1+2 ), urine fibrimopeptide A (UFPA) , and International Normalized Ratio(INR), could exactly reflect the anticoagulation intensity 48-72 hours after the replacement operation,reasonable use of anticoagulant therapy as well as accurate and in-time monitoring methods is significant to reduce complications,elevate survival rate, and improve quality of life.
Objective To explore the role of thrombus precursor protein(TPP) in the monitoring of anticoagulation in the patients with atrial fibrillation (Af) after mechanical heart valve replacement, and suggest the reasonable anticoagulant range. Methods Ninety patients were divided into Af group (n=45), sinus rhythm group (SR group, n=45), and control group (20 patients with non-valvular heart diseases), according to whether Af exist after mitral valve replacement. TPP concentrations and International Normalized Ratio(INR) in the anticoagulant patients were analyzed. Results In patients after mechanical mitral valve replacement, plasma TPP concentrations in both SR group and Af group were lower than that in control group (Plt;0.05,0.01), their INR value were higher than that in control group (Plt;0.01), and Af group had higher plasma TPP concentrations than that in SR group((Plt;)0.05). It was found that there existed contradictions between INR and plasma TPP concentrations in Af group. There were 28 patients with plasma TPP concentrations below 6 μg/ml and without spontaneous bleeding complications in the group with Af, who might be at the optimal anticoagulant status. Their 95% confidence of INR value was 1.90-2.30 and their plasma TPP concentration was 4.29±0.75μg/ml. Conclusion Patients with Af after mechanical heart valve replacement might have higher risk of thromboembolism, INR between 1.90 - 2.30 and plasma TPP concentration between 2.84-6.00 μg/ml might be the optimal anticoagulant therapeutic range.