Background and aim of the study: A variety of stentless heterograft conduits has been developed as alternatives for pulmonary outflow reconstruction. Herein are reported the authors' results with four different types of stentless heterograft conduit implanted during the past nine years.
Methods: Between January 1996 and March 2005, stentless heterograft conduits were used in 54 patients (mean age 9.9 +/- 7.5 years; median age 7 years; range: 1-32 years) to reconstruct the pulmonary outflow tract. The main pathologies were tetralogy of Fallot, transposition of the great arteries and aortic valve disease (Ross operation). A Baxter-Edwards Prima valve (EP) was used in three patients, a Medtronic Freestyle bioprosthesis (MF) in 27, a Cryolife Ross pulmonic heterograft (CR) in 14, and a Medtronic Contegra bovine jugular vein conduit (MC) in 10. The mean conduit diameter was 20.4 +/- 1.7 mm (range: 16-23 mm).
Results: Early mortality was 5.5%. Mean intensive care unit and hospital stays were 4.3 +/- 4.8 days and 11.7 +/- 7.2 days, respectively. Clinical follow up was complete for 92.1% of patients; the mean follow up period was 45.6 +/- 20 months. Excluding early deaths, the probability of patient survival (Kaplan-Meier) was 97.9% and 74.6% at one and five years, respectively. Transconduit gradients increased significantly in all conduit types during follow up. Conduit failure occurred in 15 patients (two EP, nine MF, three CR, one MC) at a median duration of 70 +/- 7 months (range: 56-84 months). To date, nine patients have undergone conduit re-replacement, without mortality and major morbidity. The probability of freedom from conduit failure was 91.6%, 66.4% and 27.9% at three, five and seven years, respectively.
Conclusion: Stentless heterograft conduits are suitable alternatives to homografts, with acceptable early and mid-term results. However, they do not offer any significant advantage over homografts or other conventional Dacron or pericardial conduits.