Morphologic investigation on Perceval S, a sutureless pericardial valve prosthesis: collagen integrity after collapsing-ballooning and structural valve deterioration at distance

Perceval S is a self-expandable, stent-mounted bioprosthetic valve (BPV), with glutaraldehyde treated bovine pericardium, processed with homocysteic acid as an anti-calcification treatment. The stent is crimpable but the valve insertion is done surgically via a shorter procedure which does not require sutures. Objectives: 1) Effects of in vitro crimping and ballooning on collagen integrity. 2) Pathology of Perceval S explants, with special reference to structural valve deterioration. Material and methods: 1) Twelve unimplanted Perceval S BPVs, time collapse 15, 60 and 180 min (4 devices per time interval), were studied. Four uncollapsed BPVs served as control. Gross examination, histology and scanning electron microscopy were performed. Collagen periodicity (μm) was measured in each group. 2) Twenty-four Perceval S explants, available from failure during clinical trials, were submitted to gross, X-Ray and histological study. Results: • There was no difference in cusp collagen integrity after crimping and ballooning, when compared to controls. • Calcification with stenosis occurred in 4 cases (time of explant 58.2 ± 4.1 months) and isolated stenotic fibrous tissue overgrowth in other 4 (time to explant 24.2 ± 12 mos). Conclusions: Collapsing and ballooning do not alter cusp collagen periodicity. Structural valve deterioration with stenosis, due to dystrophic calcification and fibrous tissue overgrowth, seldom occurred in the mid-term. Glutaraldehyde fixed pericardium has the potential to undergo structural valve deterioration with time, similar to well-known BPV failure. This supports the recommendation to pursue improvement of tissue valve treatment with enhanced durability.