Hand-made valved conduit with high-porosity knitted graft and glutaraldehyde-treated autologous pericardial trileaflet valve

Reconstruction of trileaflet pulmonary valve using autologous pericardium

Tetralogy of Fallot with atretic or absent pulmonary valve may require pulmonary valve replacement or reconstruction. We propose a technique of reconstruction of a trileaflet valve at the level of the pulmonary annulus using untreated autologous pericardium. Six cases operated upon, using this technique, had trivial pulmonary regurgitation with a median gradient of 24 mmHg (18-38) across the newly created valve. This approach can be considered in cases with limited availability of more suitable alternatives.

Valves in development for autogenous tissue valve replacement

Currently available valve and conduit artery substitutes have one or more significant disadvantages including limited durability, thrombogenicity, susceptibility to infection, and a lack of growth potential. Prior attempts to use autologous tissues in the construction of valve or arterial substitutes to overcome some of these limitations have not been successful. The use of tissue engineering techniques to construct valve and arterial substitutes from individual autologous cell lines and biodegradable polymer scaffolds are now under investigation in the laboratory, and the initial short term results in animals have been encouraging. These tissue engineering techniques offer the possibility of creating structures for replacement of valves and conduit arteries which are viable and have the capacity for self-repair and therefore greater durability. In addition, these structures should be non-thrombogenic and less susceptible to infection, and will have growth potential. Copyright 1999 by W.B. Saunders Company

Time-dependent effect of glutaraldehyde on the tendency to calcify of both autografts and xenografts

To determine mechanisms responsible for the reduced calcification in short-term glutaraldehyde (Glu)-treated autologous pericardial bioprostheses, we studied the time effect of Glu on subsequent calcification and differences in calcification of autograft and xenograft implants in a rat subcutaneous implantation model. In experiment 1, four groups of bovine pericardial pieces (1 cm2) were prepared: (A) fresh bovine pericardium without Glu, (B) with 15-minute Glu, (C) with 60-minute Glu, and (D) with 120-minute Glu. Seven young male Sprague-Dawley rats were used; each received four bovine pericardial pieces from group A, B, C, or D for subcutaneous implantation. Calcium content of the implants (microgram/mg dry weight) 45 days later was 4.8 +/- 2.9, 29.8 +/- 13.6, 106.3 +/- 13.7, and 176.3 +/- 85.5 in groups A, B, C, and D, respectively (p < 0.05 between any two groups). Experiment 2 used 8 young male Sprague-Dawley rats from different mothers. Each received five subcutaneous skin implants. The five skin implants were prepared as follows: (1) fresh self skin, (2) self skin with 30-minute Glu, (3) self skin with 48-hour Glu, (4) fresh skin of others, and (5) skin of others with 48-hour Glu. After 45 days of implantation, the calcium content of the implants was 1.4 +/- 1.1, 57.9 +/- 35.4, 142.7 +/- 61.4, 1.5 +/- 1.1, and 94.9 +/- 24.1 micrograms/mg dry weight in groups 1, 2, 3, 4, and 5, respectively (p < 0.05 for 1 versus 2, 3, or 5; 2 versus 3, 4, or 5; 3 versus 4; and 4 versus 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Autologous glutaraldehyde-treated pericardial valved conduit: an experimental study

Extracardiac conduits in the form of allografts and synthetic tubes containing heterograft valves have been used widely in the management of ventricular outflow abnormalities and for establishing ventriculoarterial continuity. These procedures are limited by long-term calcification as well as by formation of neointimal peel, necessitating reoperation. In an effort to continue the search for an alternative conduit, we designed and evaluated a valved sinus-bearing conduit fashioned out of autologous pericardium treated with glutaraldehyde. The construction of the conduit is described. The results of implantation of these conduits in 12 sheep showed no progression of gradients, fresh regurgitation, or evidence of wall or cusp calcification 9 months after implantation.

Mitral valve remodeling using autologous pericardium: an experimental study

The aim of this study was to assess in vivo the efficacy of a new technique for remodeling the mitral valve. In 6 dogs during cardiopulmonary bypass and cardioplegic cardiac arrest, both mitral valve leaflets were totally separated from the mitral ring and resected subtotally, leaving intact their narrow margins with insertion sites of the chordae tendineae of the first and second order. To mimic pathologic conditions, the chordae tendineae were then altered by placing two shortening sutures for every chordal stem. Based on standardized geometric calculations and using autologous pericardium treated with 0.62% glutaraldehyde solution, the new leaflets were then remodeled intraoperatively and sutured in place, merging them with the subvalvular apparatus and the native mitral ring. After restoration of stable circulatory conditions, valve function was evaluated under rest and defined loading conditions using a 5.0-MHz ultrasound transducer, applied epicardially. We found that intraoperative remodeling of the mitral valve leaflets using autologous pericardium with preservation of the subvalvular apparatus is possible and reproducible, and can be performed even when the subvalvular apparatus is altered morphologically. Functionally, the remodeled valve proved to be satisfactory under conditions of rest and stress. The benefits conferred by autologous tissue, the reproducibility of the surgical technique, the good functionality of the remodeled valve, and the preservation of the subvalvular apparatus could make this technique a useful surgical alternative for extensive mitral valve reconstruction procedures in pediatric and adult patients.

Glutaraldehyde treated autologous pericardium in complete repair of tetralogy of Fallot

Pericardium has been used for decades to facilitate the repair of tetralogy of Fallot (TOF). The impact of glutaraldehyde preserved autologous pericardium when used as a right ventricular outflow tract (RVOFT) patch in TOF was analyzed in 36 consecutive children undergoing complete transventricular repair. In 18 (group I) the pericardium was treated in conventional fashion (harvested and preserved in saline solution). In the other patients, the pericardium was treated in 0.625% glutaraldehyde solution for 20 minutes and then washed in saline prior to being implanted as an RVOFT patch (group II). The perioperative (prior to hospital discharge) as well as the 6-month postoperative Doppler echocardiograms were assessed with 100% follow-up. The studies were evaluated and graded by blinded observers for the presence and severity of an RVOFT dilatation (+0 to +4) relative to the size of the aortic valve annulus. The age of patients in group I and group II (29 months, 34 months) were similar as was the incidence of transannular patching (44%, 41%). Postrepair hemodynamics revealed no significant difference in the right ventricular/left ventricular pressure ratios (42%, 41%) or in the systolic RVOFT pressure (24 mmHg, 29 mmHg). The predischarge echocardiograms showed no outflow tract (OFT) dilation in either group. There was no morbidity or mortality in either group. At approximately 6 months postoperatively (6.2 mo, 5.7 mo), 72% of group I patients had RVOFT diameters that were larger (+1, +2) than the predischarge diameters when reviewed by three observers. In group II there was a single patient with dilatation of the RVOFT and this graded as +1.(ABSTRACT TRUNCATED AT 250 WORDS)