[Surgical treatment of mitral valve malformations--25 years of experience]. / Chirurgiczne leczenie wad zastawki mitralnej--25 lat doswiadczen.

During a period of 25 years (1979-2004), 24060 operations with extracorporeal circulation were performed. Of them 9536 (39.6%) were valvular procedures and 763 were combined with coronary bypass grafting. 4315 pts were operated (45.3% of valvular operations) because of mitral valve disease 5559 mitral valves were corrected, including multivalvular and combined procedures. Initially, mitral surgeries were predominant, but currently aortic valves are operated two times more frequently. In 85.5% of cases mitral valve replacement was necessary (with prosthetic valve), but 803 pts underwent reconstructive surgery (445 commissurotomies and 358 valvo/annuloplasties, including 135 implantations of annuloplasty rings). Additionally, 421 DeVega tricuspid valve annuloplasties were performed, and 15 tricuspid rings were implanted. Because of infective endocarditis 182 mitral valves were corrected, including the replacement of 78 infected prostheses. The pts age varied between 10 and 85. In 1980 the mean age was 40, but currently it has increased to 55, and the pts with coronary artery disease are approximately 10 years older. The general mortality among pts with ECC was 4.2% in 2003, and after valvular procedures 4%. The mortality after mitral valve replacement diminished from 12% to 4.5-5%, and after reconstructions was two times lower. The mortality among pts with endocarditis was 11.8%. Several characteristic trends were observed: increase of the number of elder pts, decrease of mitral valve procedures in comparison with aortic ones, more common coincidence of coronary artery disease, better preoperative status of the pts, and decrease of the operative risk.

Mineralization and organic phase modifications as contributory factors of accelerated degeneration in homograft aortic valves.

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess histological and mineralogical properties of leaflets in human, antibiotic-preserved aortic homograft valves (recovered during surgical replacement) in order to identify factors accounting for pathological changes leading to accelerated graft dysfunction. A comparison was made with aortic valves prepared for grafting, with a view to assessing morphological and mineralogical characteristics as a potential preimplantation risk factor. METHODS: Valve leaflets were examined with light and scanning electron microscopy. Mineralization was assessed histochemically, and also physicochemically by atomic absorption spectroscopy (AAS). RESULTS: All explanted homograft valve leaflets revealed prominent degenerative changes seen as decreased surface area, fibrosis, mineralization and focal thrombosis. Substantial loss of endothelium and fibroblasts, reduced collagen bundles crimping, inflammation (81%) and disappearance of layered structure (59%) was identified. The elastic elements were relatively stable, though a gradual age-dependent loss was observed in both groups. Accelerated mineralization was seen in all explanted homografts; inorganic deposits were composed mainly of hydroxyapatite. Two types of mineralization were identified: large limited nodular structures, and diffuse mineral deposits. Homografts with moderately elevated mineralization, well-preserved layered structure and sporadic infective changes proved to have the greatest durability. Homograft durability was also affected by the difference in host and donor age. CONCLUSION: Preimplantation factors affecting pathological changes determining homograft durability included morphological status of the graft itself and donor age; host-related factors included recipient age, endocarditis, native valve calcification, and host-donor matching (age difference between host and donor). A limited molecular mineralization may increase valvular durability, provided that no focal nodular calcifications exist that might adversely affect overall homograft integrity.

Reoperation after fresh homograft replacement: 23 years' experience with 655 patients.

OBJECTIVE: Through a retrospective study on the use of fresh homografts in 655 aortic valve replacement patients over a period of 23 years, we aimed to assess the reasons for eventual reoperation and causes of valve dysfunction. METHODS: Between January 1980 and December 2002, 655 patients received fresh homografts. All homografts were antibiotic sterilized and stored at 4 degrees C. During this time, 139 patients (116 male and 23 female) with a mean age of 46.7 years (range 18-72) required reoperation. RESULTS: The 30-day hospital overall mortality was 2.87%. The mean durability for all homografts was 12.4+/-4.54 years (1 month to 23 years). The cumulative rates for freedom from reoperation for any cause were 94.09+/-2% at 5 years and 87.9%+/-4% at 10 years, 76.6 at 15 years, 49.55 at 20 years. The major cause of valve dysfunction and indication for reoperation was degeneration in 111 patients (79.8%). Predominant aortic valve insufficiency in 87 patients (62.5%) and predominant stenosis in 24 patients (17.26%). Endocarditis occurred in 21 patients (15.1%). Early endocarditis was diagnosed in five patients (3.59%), late endocarditis in 16 patients (11.5%). Additional causes for reoperation included ascending aortic aneurysm, mitral valve insufficiency and congestive cardiomyopathy. Seventeen patients (12.2%) required concomitant procedures. Coronary artery bypass grafting was performed in six cases (4.3%), mitral valve replacement in five cases (3.59%), mitral valve annuloplasty in six (4.3%). The primary reoperative procedure was artificial/mechanical aortic valve implantation. In five cases, St. Jude Medical conduit grafts were implanted due to ascending aortic aneurysms. Homograft reimplantation was performed in four cases. One patient underwent mitral valve replacement and one patient received a heart transplant. CONCLUSION: The results of the study suggest that reoperation in patients with aortic homografts is a low-risk procedure as compared to alternative therapies. Primary allograft aortic valve replacement can give acceptable results for up to 23 years. The major cause of valve dysfunction and indication for reoperation was degeneration. Cumulative rates for freedom from reoperation for any cause in age groups suggest careful selection and indications in homograft implantation in the younger patients. Young age is a risk factor for an early homograft structural deterioration (degeneration).

[Implants with aortic valve homografts in patients with critical left aortic stenosis]. / Przyklady zastosowania zastawek homogennych u chorych z krytycznym zwezeniem lewego ujscia tetniczego.

This case study presents two patients with aortic stenosis and infective endocarditis (IE) who underwent homograft aortic valve replacement. The first patient is a 67 year old practicing surgeon. Twenty one years ago, he was admitted to our department for critical aortic stenosis, infective endocarditis (IE) and heart failure. He underwent homograft aortic valve replacement. After the surgery his condition improved dramatically and he returned to his practice. Current echocardiographic study shows normal function of the left ventricle and normal gradient across homograft aortic valve. The next case, a 33-year old happy mother of 5 children, is particularly interesting. When she was 15 years old, she was referred to surgery, diagnosed with bicuspid aortic valve stenosis, subaortic muscular stenosis and aneurysm of aortic sinus of Valsalva. She underwent homograft aortic valve and root replacement and excision of the sub-aortic muscle bulge. Eleven months later, she required another operation due to active IE. The St. Jude Medical aortic valve was implanted. Two months after the surgery a dysfunction of the implanted artificial valve was diagnosed. She again underwent the homograft aortic valve and root replacement with good long-term results. In the period spanning 1987-1997, she managed to deliver five babies without any complications whatsoever. Seventeen years later, the homograft aortic valve is still functioning fairly well. The homograft aortic valve replacement may be regarded as a viable option for patients with aortic stenosis and IE and for young women suffering from aortic valve disease who intend to be prospective mothers.