Desinsertions of aortic valve prostheses treated by subcoronary implantation of the valve

Thirteen patients requiring emergency surgery for desinsertion of their aortic valve prostheses were treated by subcoronary aortic valve grafting, using a procedure based on Danielson's method. The particularity characterizing this technique consists in obtaining direct revascularization of the left coronary artery via a coronary sinus approach, thereby reducing the complexity of the surgical operation. All the patients presented valvular ring lesions, associated with aortic root degeneration accountable for failure of conventional artificial aortic valve replacements; in 8 patients, this had been their third aortic prosthetic surgery. The mean survival period for eight patients was 44 months. Considering the highly critical aspect of such lesions, this technique apparently constitutes a working solution, barring all chances for relapse.     

Five-year experience with Lillehei-kaster prostheses in the aortic position

From 1972 through 1976, 140 patients underwent aortic valve replacement (AVR) with the Lillehei-Kaster (LK) prosthesis and 18 additional patients had AVR plus coronary bypass procedures. Follow- up information was obtained in 98% of the patients. The operative mortality rate was 7.5% and the actuarial 5- year survival rate was, 79%. Two episodes of thromboembolism occurred in 3,645 patient-months. Prosthesis malfunction or significant hemolysis has not occurred. Postoperative catheterization studies revealed a functional valve area of 0.81 cm² with the 14A prosthesis; all other valve areas were greater than 1.1 cm². Continued use of the LK aortic valve prosthesis with warfarin anticoagulation is recommended in sizes greater than 14A.

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Résumé Entre 1972 et 1976, 140 malades ont subi un remplacement de valve aortique avec une prothèse de Lillehei-Kaster (LK) et 18 autres un remplacement valvulaire aortique combiné à un bypass coronaire: 98% des cas ont été suivis. La mortalité postopératoire est de 7.5%. La survie actuarielle à 5 ans est de 79%. Il y a eu 2 épisodes de thrombo-embolie sur 3,645 mois/malades. Il n'y a eu ni malfonction de la prothèse, ni hémolyse significative. Le cathétérisme postopératoire montre une surface fonctionnelle de la valve de 0.81 cm² pour les prothèses 14A et de 1.1 cm² pour les autres valves. Nous recommandons l'emploi de valves aortiques LK de tailles supérieures à 14A avec anticoagulation par warfarine.

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Presented at the XXVIIth Congress of the Société Internationale de Chirurgie, Kyoto, Japan, September 3–8, 1977.

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Dr. Mayer is supported by a National Research Service Award from the National Institute of Health.     

Biological versus mechanical prostheses for aortic valve replacement

ObjectivesLong-term real-world outcomes are critical for informing decisions about biological (Bio) or mechanical (Mech) prostheses for aortic valve replacement, particularly in patients aged between 50 and 65 years. The objective was to compare long-term survival and major adverse cardiac and cardiovascular events (ie, stroke, reoperation, and major bleeding) within this population.MethodsThis was a multicenter observational study including all patients aged between 50 and 65 years who underwent an aortic valve replacement because of severe isolated aortic stenosis between the years 2000 and 2018. A total of 5215 patients from 27 Spanish hospitals were registered with a follow-up of 15 years. Multivariable analyses, including a 2:1 propensity score matching (1822 Mech and 911 Bio) and competing risks analyses were applied.ResultsBio prostheses were implanted in 19% of patients (n = 992). No significant differences were observed between matched groups in long-term survival (hazard ratio [HR], 1.14; 95% confidence interval [CI], 0.88-1.47; P = .33). Stroke rates were higher for Mech prostheses, but not significant (HR, 0.72; 95% CI, 0.50-1.03; P = .07). Finally, higher rates of major bleeding were found in the Mech group (HR, 0.65; 95% CI, 0.49-0.87; P = .004), whereas reoperation was more frequent among the Bio group (HR, 3.04; 95% CI, 1.80-5.14; P < .001). Bio prostheses increased from 13% in the period from 2000 to 2008 to 24% in 2009 to 2018.ConclusionsLong-term survival was comparable among groups in patients between 50 and 65 years of age. Mech prostheses were associated with a higher risk of major bleeding, whereas Bio prostheses entailed higher reoperation rates. Bio prostheses seem a reasonable choice for patients between 50 and 65 years in Spain.     

Design and construction of fascia lata aortic valve prostheses

Current techniques for constructing fascia lata aortic valves result in a valve in which redundant cusp tissue is inadvertently incorporated in the proximal part of the cusp. This alters the flow character of the valve and produces a significant stenosis. An alternative technique, based on the normal anatomy of the aortic valve, is suggested which eliminates this fault. The technique is simple and can be used at the time of operation.     

Mechanical hemolysis in patients with mitral and aortic valve prostheses

The examination of 25 patients operated upon has shown that alterations of functions of the artificial prostheses of the heart valves can be timely detected by a complex of laboratory studies (determination of activity of lactate dehydrogenase, osmotic resistance of erythrocytes, reticulocyte content, hemoglobin and morphological features of erythrocytes).     

Perforation of congenitally deformed aortic valve resulting in aortic insufficiency. Report of case successfully treated by aortic valve replacement.

This 40-year-old male presented with the signs and the symptoms of acute aortic insufficiency and underwent aortic valve replacement. At surgery a deformed aortic valve with perforation was found. This represents a unique example of a congenitally deformed aortic valve complicated by acute perforation with resultant valvular incompetence.     

Comparative hemodynamic characteristics of Soviet-made mechanical heart valve prostheses in the mitral position

The article deals with hemodynamic evaluation of Soviet-made, and heart valve prostheses in late-term periods after operation for mitral valve replacement. Fourty-six patients were examined: a ball prosthesis was implanted in 21 patients (1st group), as disk prosthesis--in 15 patients (2nd group) and a prosthesis--in 10 patients (3rd group). A good clinical result of the operation was achieved in all patients, they were referred to functional class I and II. Catheterization of the left and right parts of the heart, left ventriculography, and test with dosed physical exertion were carried out. Loading was continued till cardiac output increased approximately by 60 per cent in 6 patients of the 1st group, 12 patients of the second group, and in all 10 patients of the 3rd group. The study showed that the prostheses do not yield to foreign models of heart valves in hemodynamic characteristics and cause a lower stenosing effect than the prostheses do. No essential differences were detected between the prostheses.     

Biomechanics of the pulmonary autograft valve in the aortic position.

Pulmonary autograft valve replacement has been simulated by implanting the pulmonary valve into the aortic position of the same cadaver heart from both human and porcine sources. The forces acting on the pulmonary valve leaflets have been calculated on the basis of a triaxial ellipsoid mathematical model. These forces on the pulmonary autograft valve were shown to be essentially similar to those previously reported for aortic valve leaflets. Biomechanical measurements have been made on the simulated autograft valves and on the isolated pulmonary valve cusps. The tensile strengths of the pulmonary valve cusps in both circumferential and radial directions were roughly three times greater than those of aortic valve cusps. This indicated the ability of the pulmonary valves to accept, ab initio, aortic valve closing pressures. Pressure-induced changes in dimension, calculated on the basis of diameters of the simulated pulmonary autograft root, also indicated that the distensibility of the autograft valve was limited. It reached a maximum at 30 mm Hg (4 kPa) without any suggestion of further distension to the point of distortion and incompetence. The combination of the calculated forces acting on the valve and the biomechanical measurements have shown that pulmonary valves used as autograft aortic valve replacements are able to tolerate aortic pressures from the time of implantation. These experimental results from simulated autografts support the clinical use of this valve over the past 13 years.     

The pericardial valve in the aortic position ten years later

To assess the behavior of the pericardial valve at 10 years after implantation, the cases of 240 patients who had undergone aortic valve replacement with the standard Ionescu-Shiley (Shiley, Inc., Irvine, Calif.) bovine pericardial valve between February 1977 and December 1983 were reassessed. Follow-up of the 224 hospital survivors was 99.6% complete. Fifty-seven valve-related events occurred. Fourteen were thrombotic events (1.2%/patient-year), 28 were intrinsic tissue failures (2.4%/patient-year), 13 were cases of prosthetic valve endocarditis (1.1%/patient-year), and 2 were paravalvular leaks (0.17%/patient-year). The linearized rate for death, reoperation, or both resulting from valve-related events was 3.6%/patient-year. Time-related hazard function for the instantaneous risk of death and/or reoperation resulting from valve-related events demonstrated an exponential increase after 80 months. These data, in conjunction with our previous reports on the histologic changes in pericardial collagen and the incidence of calcification (26/28), should be considered regarding new and future generations of pericardial bioprostheses. Although this device provides good hemodynamics and carries a low incidence of thromboembolism, it has a limited durability. New generations of pericardial valves may have improved structural features, but the behavior of glutaraldehyde-fixed, formaldehyde-stored bovine pericardium as currently selected and prepared is unlikely to change.