Right ventricular outflow tract reconstruction: valved conduit of choice and clinical outcomes

Abstract

Conduit failure and explant is inevitable. This phenomenon is worse with a longer follow-up. Mechanisms involved in conduit failure are unknown, even though they were accounted for by calcification and extensive intimal proliferation, and somatic outgrowth. Homografts are commonly used and have experienced a long history. The pulmonary homograft is the most commonly used RVOT conduit, especially in small children, due to its excellent characteristics. The newly-developed Contegra conduit has become popular due to its availability in full sizes and the acceptable results obtained at intermediate follow-up. The Hancock conduit can function sufficiently well for as long as 5-10 years, and early valve failure is relatively rare. It is admissible to use the Hancock conduit as an interim measure for future conduit reoperation due to its adequate function until subsequent operation. The application of an autologeous tissue valved conduit should be considered when other alternatives are not available.

Use of Fresh Decellularized Allografts for Pulmonary Valve Replacement May Reduce the Reoperation Rate in Children and Young Adults

“…1 However, implantation of these valves in pediatric patients often results in graft degeneration and failure. 1 Degradation of allografts and xenografts is usually attributed to high immunologic competence in children and young adults and leads to repeated operations.…”

“…1 However, implantation of these valves in pediatric patients often results in graft degeneration and failure. 1 Degradation of allografts and xenografts is usually attributed to high immunologic competence in children and young adults and leads to repeated operations. 2 Heart valve tissue engineering represents an upcoming alternative source to create viable, nonimmunogenic, and biologically active grafts.…”

Fresh Autologous Pericardium to Reconstruct the Pulmonary Valve at the Annulus When Tetralogy of Fallot Requires a Transannular Patch at Midterm

“…25 Attempts to create pulmonary leaflets for bicuspid PVs with biologic and polytetraf luoroethylene (PTFE) materials have shown good early results: some studies have proved their efficacy even at midterm or longer. 26,27 Conversely, the construction of a monocusp from a homograft has been associated with destruction consequent to ABO blood group incompatibility, and with poor valvular function at midterm. 28 Although thin and impervious to the growth of fibrous tissue, PTFE is known to calcify in the long term.…”

Adipose Derived Tissue Engineered Heart Valve

“…Current best clinical practice consists of surgical prosthetic heart valve replacement [3][4][5]. These valves can be either a mechanical, biological allogenic [6,7] or xenogenic [8] prosthesis. Unfortunately these replacements suffer from disadvantages associated with clinical limitations such as necessary lifelong anti-coagulation treatment, risk of immunogenic reactions or adverse reaction such as extensive calcification and degradation giving rise to possible reoperations [9,10].…”