• Journal of Chest Surgery
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• v.37 no.7
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• pp.559-569
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• 2004

The CarboMedics mechanical valve has been reported to show acceptable valve-related complication rates. The aim of this study is to evaluate our clinical experience with the CarboMedics valve. Material and Method: Between August 1988 and September 1999, we implanted 1,144 CarboMedics valves in 850 patients (aortic 179; mitral 385; double-valve 234; tricuspid 52). The mean age was 44.5 $\pm$ 12.5 years. Follow-up was completed in 95.2% and median follow-up period was 7.9 years (6753 patient-years). Result: The overall hospital mortality rate was 3.4% and the mortality rate for each group was 1.7% for aortic group, 2.6% for mitral group, 4.7% for double-valve group, and 9.6% for tricuspid group, Tricuspid group showed significantly higher mortality rate than aortic and mitral group (p〈0.05). The actuarial survival at 10 years was 87.1 $\pm$ 2.6%, 88.9 $\pm$ 1.7%, 82.4 $\pm$ 2.9%, and 77.5 $\pm$ 7.0% for aortic, mitral, double, and tricuspid valve group, respectively. Age and tricuspid valve replacement were significant risk factors for long-term survival in multivariate analysis (p 〈 0.05). Freedom from valve thrombosis at 10 years was 99.4 $\pm$ 0.6%, 98.2 $\pm$ 0.8%, 99.2 $\pm$ 0.8%, and 87.6 $\pm$ 0.5% for aortic, mitral, double and tricuspid valve group. Tricuspid valve group showed significantly higher rate of valve thrombosis (p 〈 0.05). Conclusion: Long-term results of our experience demonstrated that CarboMedics valve showed acceptable incidence of valve-related complications. However, tricuspid valve replacement showed higher rate of early mortality and valve thrombosis than other valve replacement groups.

• Journal of Power System Engineering
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• v.14 no.5
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• pp.41-47
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• 2010

티타늄과 티타늄 합금은 재료적 특이성 때문에 심장 혈관 임플란트에서 일반적으로 사용되어 왔다. 일찍이 적용된 예로는 인공심장판막, 심박조율기의 보호케이스, 혈액 순환 장치 등이 있다. 하지만 물질유도혈전증(Material-induced thrombosis)은 혈전폐색에 의해 기인한 기능 손실로 심장혈관 임플란트 장치의 주된 합병증으로 존재하고 있으며, 심장혈관 임플란트의 혈전유전자는 심장혈관장치의 발달에 주된 난관 중 하나로 남아있다. 그리고 텍스처 혈액 접합 물질(Textured blood-contacting material)은 1960년대 초반 이후부터 혈액순환 보조 장치의 임상실험에 사용되고 있다. 접합 물질에 내장된 텍스처 섬유조직 표면은 형성, 성장, 안정적 부착, 생물학적 내벽(neointimal layer) 등 유도 혈액(entrapping blood) 성분에 의해 형성된다. 공동(cavity) 형상의 용해 가능한 미립자를 사용하는 SCPL법(Solvent casting/particulate leaching method)은 티타늄 기질 이전에 형성된 폴리우레탄 위에 텍스처(texture)를 생성하기 위해 사용되었다. 또한 콜라겐의 부동화(不動化)에 의한 공동(cavity)은 혈액 접합면에 잔존하기 위한 내피세포를 고정할 수 있는 효과가 있다. cpTi로 층화된 PU 기소공성(microporous)은 구조적 특성과 혈전증 감소를 위한 생물학적 내벽 사용의 잠재성을 평가하기 위한 세포 공동체 실험을 통해서 평가되었다.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1165-1171
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• 1998

Background: All currently available mechanical and bioprosthetic valves are associated with various types of deterioration leading to dysfunction and/or valvular complications. Reoperation on prosthetic heart valves is increasingly under consideration for both clinical and prophylactic indications. This review was conducted to determine the factors affecting the risk of reoperation for prosthetic valve replacement. Material and method: From January 1985 to July 1996, 124 patients underwent reoperation on prosthetic heart valves, and 3 patients had a second valve reoperation. The causes of reoperation were prosthetic valve failure(96 cases, 77.4%), prosthetic valve thrombosis(16 cases, 12.9%), prosthetic valve endocarditis(7 cases, 5.6%) and paravalvular leak(5 cases, 4.1%). This article is based on the analysis of the experience with particular emphasis on the preoperative risks affecting the outcome of the reoperation. Result: Overall hospital mortality rate was 8.9%(11/124). Low cardiac output was the most common cause of death(70.6%). Left ventricular systolic dimension(p=0.001), New York Heart Association functional class IV(p=0.003) and serum creatinine level(p=0.007) were the independent risk factors, but age, sex and cardiothoracic ratio did not have any influence on the operative mortality. Follow-up period was ranged from 3 to 141 months (mean, 50.6 months). A late mortality rate was 1.8%. Conclusion: The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, therefore reoperation is recommended before the hemodynamic impairment become severe.

• Journal of Chest Surgery
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• v.31 no.3
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• pp.242-246
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• 1998

From January 1988 to December 1995, 27 patients, 11 men and 16 women, underwent surgical intervention at our institution for prosthetic valve dysfunctions. The mean age was 43.5$\pm$12.2 years. Seventeen(63.0%) patients had the mitral valve replacement, 8(29.6%) the aortic valve, 1(3.7%) the aortic composite graft, and 1(3.7%) the tricuspid valve. Mean follow-up period was 49.5$\pm$30.9 months. In 12 bioprostheses, mean interval between the previous valve replacement and the reoperation was 104.9$\pm$34.9 months. The causes of redo surgery were structural deterioration of the prosthetic valve (12/12, 100%), paravalvular leak (2/12, 16.7%), and prosthetic valve endocarditis(1/12, 8.3%). In 15 mechanical prostheses, the mean interval was 55.2$\pm$43.7 months. The causes of redo surgery were pannus formation (8/15, 53.3%), paravalvular leak(4/15, 26.7%), and valve thrombosis(3/15, 20.0%). Posto- perative complications occurred in 7 patients (25.9%). There was no intraoperative death. But one patient, who received mechanical aortic valve replacement died on the 3rd postoperative day due to low cardiac output and multiorgan failure.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.977-982
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• 1996

Cardiac valve implantation was performed in 107 patients from September, 1988 to May, 1995. There were 3) men and 74 women, whose ages ranged from 19 to 75 years(mean 42.6$\pm$11.7). Mitral valve was implanted in 61 patients, double(mitral & aortic) valve were Implanted in 28 patients and aortic valve was implanted in 18 patients. Follow up was 100% complete, with 345.6 patient-years and a mean fo low up of 41 months(from 1.5 to 84 months). The total mortality was 14.9%(16 patients). The early mortality was 5.6%(6 patients) and the late mortality was 9.3%(10 patients). The overall actuarial survival was 92.6 $\pm$ 2 6% at 2 years, 88.6$\pm$3.8% at 6 years. The probability of freedom from valve failure, thromboembolism and bacterial endocarditis were 388.6 $\pm$ 3.8, 88.3 $\pm$3.9, 89.5 $\pm$3.7 at 6 years, respectively.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.287-292
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• 1997

.Itrial fibrillation is one of the most common cardiac arrhythmias requiring treatment. About 60% of patients with mitral valvular disease have atrial fibrillation and one third of patients with atrial fibrillation may have the past history of thromboembolic events. Between April 1994 and June 1995, 20 patients with organic heart diseases combined with atrial fibrillation underwent open heart surgery including Cox-maze 111 procedure. There were 6 men and 14 women with an average age of 48 years (range, 31 to 66 years). Nineteen patients had valvular heart diseases and 1 ventricular septal defEct (VSD). Mean duration of atrial fibrillation was 36 months (:42 months) (range, 1 to 132 months). T e past medical history of thromboembolic events was positive in 7 patients (35%) and left atrial thrombus was detected in 9 patients (45%). The concomitant procedures were mitral valve replacement (MVR) and aortic valve replacement (AVR) in 5 patients, MVR in 4, MVd and tricuspid annuloplasty(TAP) in 4, mitral valvuloplasty(Mln) in 3, Mln and Tln in 1, MIW and coronary artery bypass surgery in 1, AVR in 1, and patch closure of VSD in 1. Mean aortic cross-clamping time was 175 minutes (range, 116 to 270 minutes). Atrial fibrillation recurred in 16 patients (80%) during the early postoperative period, but, recurrent atrial fibrillation was converted to regular rhythm at postoperative forty-first day in average. There was no early or late death in this series of 20 patients and postoperative complications were inappropriate tachycardia in 5 patients (25%), low cardiac output syndrome in 3 (15%), aggravated hemiplegic in 1, and acute renal failure in 1. Mean follow-up interval of patient was 16.5 months (range, 10.5 to 24 months) and all patients are currently in regular rhythm. Seventeen patients (85%) are in sinus rhythm and 3 (15%) in junctional rhythm. Right atrial contraction was detected in 95% of patients and left atrial contraction in 63% on postoperative transthoracic echocardiogram. The surgical treatment of atrial fibrillation concomitant with open heart surgery is warranted in the recent clinical setting of improved myocardial protection technique, considering the untoward side-effects of atrial fibrillation.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.1-7
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• 2007

Backgound: It has been shown that the endothelium of cardiac valves and adjacent great vessels have a reduced immune reaction compared to other vessels. We investigated the clinical feasibility of using immunologically untreated xenogenic valves, in a pig-to-goat pulmonary valve conduit implantation model. Material and Method: Porcine pulmonary valve conduits were prepared without specific immunologic treatment and implanted into the right ventricular outflow tract of goats while undergoing cardiopulmonary bypass. Two goats each were assigned to the following observation time intervals: one day, one week, three months, six months and twelve months. Echo-cardiographic examinations were performed prior to sacrifice of the goat to evaluate pulmonary valve function. After the xenograft specimens were retrieved, histological changes were evaluated microscopically. Result: Ten of the twelve animals survived the predetermined observation time intervals. Aneurysmal dilatations, of the anterior wall of the implanted pulmonary artery, were observed at each of three and twelve month-survival animals. A variable degree of pulmonary valve regurgitation was observed on echocardiography. However, valve stenosis, thrombotic occlusion and vegetation were not seen. Microscopically, the nuclei of the donor tissue disappeared as a result of pyknosis and karyolysis; however the three components of the implanted xenografts (the pulmonary artery, the valve and the infundibulum) were gradually replaced by host cells over time, while maintaining their structural integrity. Conclusion: Immunologically untreated xenogenic pulmonary valve conduits were replaced by host cells with few observed clinical problems in a pig to goat pulmonary valve implantation model. Therefore, they might be an alternative bioprosthesis option.

• Journal of Chest Surgery
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• v.39 no.12 s.269
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• pp.900-905
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• 2006

Background: Homografts and bioprostheses are most commonly used for Rastelli operation in congenital heart disease, but the limited durability is responsible for multiple reoperations associated with increased morbidity This study evaluated long-term results after Rastelli operation with a mechanical valved conduit. Material and Method: A total of 20 patients underwent Rastelli operation with mechanical valved conduit from January 1990 to July 1992. Operative mortality was 1 of 20 patients, and a retrospective review of 19 patients(10 males, 9 females) was done. Initial diagnosis was congenitally corrected transposition of great arteries(cc-TGA, n=4), complete TGA (n=2), ventricular septal defect with pulmonary atresia(VSD with PA, n=9), truncus arteriosus(n=2), double outlet right ventricle with pulmonary stenosis(DORV with PS, n=2). The mean age at Rastelli operation was $4.6{\pm}3.4$ years, and mean follow-up period was $12.8{\pm}2.7$ years. Patients underwent Rastelli opearation using 16 CarboMedics mechanical valve, and 3 Bjork-Shiley mechanical valve($17{\pm}2$ mm). Result: There were 15 reoperations for failed mechanical valved conduit. The freedom from reoperation at 5 and 10 years was 53% and 37%. Most patients were received oral anticoagulation with warfarin, and maintained the international normalized ratio(INR) of 1.5 to 2.0. There was no anticoagulation or thromboembolism related complication. There was a significant difference in the causes of a conduit failure between early(within 3 years) and late(after 3 years) failure groups. The six patients reported early prosthetic valve failure, mainly due to valvular dysfunction by thrombosis or pannus formation. The other nine patients reported late prosthetic valve failure, mainly due to dacron conduit stenosis at anastomosis sites, whereas their valvar motion was normal except 1 patient. Conclusion: To avoid early prosthetic valve failure, strict anticoagulation therapy would be helpful. About the late development of obstructive intimal fibrocalcific peels within the Dacron conduit, an improvement of conduit material is necessary to reduce late prosthetic valve failure. In selected patients, the long term results were satisfactory.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.358-363
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• 1999

Background: Recently, many cardiac centers have been using aprotinin to reduce operative bleeding in cardiac operations using cardiopulmonary bypass. A variety of reports have confirmed the effectiveness of the drug in cardiac operations. In addition to the operations which could be considered to cause severe operative bleeding such as redo operation, long cardiopulmonary bypass operation and etc, the use of aprotinin is increasing in the field of primary cardiac operations. Varying doses of regimen have been introduced since the first report by Royston et al, and also various opinions on the effectiveness and safeness of the each regimen have been reported. We reviewed our own experience of the full dose aprotinin regimen(Hammersmith regimen) retrospectively. Material and Method: From October 1994 to February 1998, 40 cases of cardiac operative patients were randomized into two groups: aprotinin group(20 patients) which received a full dose aprotinin regimen and control group(20 patients) which did not receive aprotinin. To evaluate the degree of bleeding decrease, we analysed and compared the amount of postoperative 6 hours and 24 hours bleeding in the each group. To confirm the renal dysfunction, we measured the postoperative creatinine level. Result: In the amount of postoperative 6 hours bleeding, a statistically significant bleeding decrease was demonstrated in the aprotinin group compared to the control group(aprotinin group: 186${\pm}$40cc, control group:409${\pm}$69cc, P=0.010). Similar result was observed in the postoperative 24 hours(aprotinin group:317${\pm}$53cc, control group: 671${\pm}$133cc, P=0.024). Conclusion: We concluded that full dose regimen of aprotinin can remarkably reduce postoperative bleeding in cardiac operations without significant renal dysfunctions.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.320-328
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• 2008

Background: Numerous surgical devices for mitral repair have been used in the past with good results. In this study we describe a simple annuloplasty technique with using a new device ($Mitracon^{(R)}$). The aim of this study was to assess its efficacy and surgical results with using $Mitracon^{(R)}$. Material and Method: From May 2003 to October 2005, 46 patients (21 women and 25 men (mean age of $51.4{\pm}17.8$ years) with mitral regurgitation from various causes were treated with either the $Mitracon^{(R)}$ (the $Mitracon^{(R)}$ group) or the Capentier Edward rigid ring (the CE group). The median follow-up duration was 18.9 months. Result: The mean grade of mitral regurgitation before and immediately after surgery in the $Mitracon^{(R)}$ group and the CE group decreased from $3.2{\pm}0.8$ to $0.6{\pm}0.7$ and $3.4{\pm}0.7$ to $0.3{\pm}0.5$, respectively. There were no significant changes in the ejection fraction either between the two groups or before and immediately after surgery. No deaths were seen in either group. Early postoperative echocardiography of all 46 patients showed only trivial mitral regurgitation or none at all. Echocardiography at a median of 18.9 months also showed no progression in mitral regurgitation. The mean grade of mitral regurgitation in the $Mitracon^{(R)}$ group at this time point decreased from $3.2{\pm}0.8$ to $0.8{\pm}0.7$ (p<0.05). The CE group also showed a similar degree of decrease from $3.4{\pm}0.7$ to $0.3{\pm}0.6$ (p<0.05). The mitral valve area in the $Mitracon^{(R)}$ group at 1 year follow-up was $3.3{\pm}0.9cm^2$. The mitral valve area in the CE group was $2.7{\pm}0.6cm^2$. The mean mitral pressure gradient in the $Mitracon^{(R)}$ group at 1 year follow-up was $3.1{\pm}1.3$ mmHg. The mean pressure gradient in the CE group was $4.5{\pm}2.1$ mmHg, although any statistical significant difference for this between the groups was not reached. Conclusion: The present study showed the described technique to be safe and effective in the intermediate term. Because long term results are unavailable, a more extensive prospective randomized multicenter trial may be warranted to determine whether this procedure should be generally applied for repair of mitral valve disease.