Replacement of pulmonary artery trunk in sheep using tubular valved heterograft in non-aldehydic preservation

INTRODUCTION: The cardiac bioprostheses are related to thromboembolic events, infectious and degenerative diseases. Wear is mainly attributed to the denaturation of collagen. Glutaraldehyde, the predominant method of preservation of bioprostheses, favors the calcification process and limits their durability. Several techniques try to contain the degenerative process of bioprostheses. OBJECTIVES: To evaluate the process of calcification in vivo pulmonary valve heterografts preserved in non-aldehydic (L-Hydro®). METHODS: Seventeen sheep underwent replacement of the pulmonary artery valved tubular grafts of bovine pericardium. The animals were divided into two groups: Group L-Hydro® (test / n = 14) and Group Glutaraldehyde (control / n = 3). About 150 days after implantation the animals were sacrificed, necropsied and implants subjected to a pathological study, radiological evaluation and measurement of calcium by atomic absorption spectrophotometry. Statistical analysis was obtained through the Fisher's exact test, Student's t or Mann-Whitney test (significance: 5%). RESULTS: The radiological evaluation, the macroscopic and microscopic measurement of serum calcium by atomic absorption spectrophotometry showed increased calcification of the prosthetic group Glutaraldehyde, when compared to denture-HydroR Group L (P = 0.001). Seven animals in Group L-Hydro® (50%) had adherence of the leaflets to the wall of the tube (P = 0.228). CONCLUSIONS: Prostheses preserved in L-Hydro® were more resistant to calcification when compared with glutaraldehyde preserved.