This study demonstrates the safety and efficacy of this engineered bovine pericardial patch as a cardiovascular substitute for surgical repair of both simple and more complex congenital cardiac defects.

In this growing lamb model the CardioCel patch allowed accurate valve repair at both systemic and pulmonary pressure. The mechanical properties of CardioCel after 7 months were preserved with a more controlled healing than the treated autologous pericardium and without calcification.

Improved biostability and durability with reduced calcification of tissues after the multistep ADAPT(®) tissue treatment suggest improved alternative substitutes to autologous pericardium.

OBJECTIVES: Durability of bioscaffolds cross-linked with glutaraldehyde and used in cardiovascular surgery is limited by biomechanical instability, calcification and reduced biocompatibility. This study compares CardioCel V R , a bovine pericardial scaffold engineered via the ADAPT V R process to ensure optimized biostability and biocompatibility, with the commonly used bioscaffolds. METHODS:Bovine pericardial scaffolds, cross-linked with 0.6% glutaraldehyde (XenoLogiX TM , PeriGuard V R ), dye-mediated photo-oxidized (PhotoFix TM ) and a non-crosslinked porcine scaffold (CorMatrix V R ), were compared with CardioCel (decellularized, cross-linked with 0.05% monomeric glutaraldehyde, detoxified) by thermal stability and mechanical tests. Biocompatibility and calcification were assessed in a juvenile subcutaneous rat model at 6 and 12 weeks. RESULTS:CardioCel displayed significantly higher (P < 0.01) cross-link stability (77.99 ± 0.64 C) than CorMatrix (57.88 ± 0.22 C) and PhotoFix (53.96 ± 0.41 C). Tensile strength of CardioCel (8.31 ± 3.36 MPa) was comparable with XenoLogiX (11.00 ± 5.43 MPa, P = 0.734), PeriGuard (16.44 ± 6.69 MPa, P = 0.136), PhotoFix (7.10 ± 6.11, P = 0.399) and CorMatrix (9.75 ± 2.61, P = 0.204). XenoLogiX and PeriGuard recorded the highest Young's modulus (67.01 ± 30.36 vs 95.67 ± 45.91 MPa), while CardioCel (50.21 ± 19.92 MPa) was comparable with CorMatrix (36.78 ± 10.47 MPa, P = 0.204) and PhotoFix (33.50 ± 10.24, P = 0.399). CorMatrix displayed a significantly (P < 0.05) greater stiffness (4.74 ± 0.77 MPa) at 10% strain than PeriGuard (3.73 ± 1.79 MPa), PhotoFix (1.59 ± 0.40 MPa) and CardioCel (3.39 ± 0.83 MPa). Differences in extractable calcium did not reach significance; however, the inorganic phosphorus content of PhotoFix (21.3 ± 9.0 mg/mg) was higher than CardioCel (11.35 ± 0.76 mg/mg, P = 0.004) or PeriGuard (10.7 ± 2.18 mg/mg, P = 0.002) at 12 weeks. CardioCel underwent a typical mild host-graft response with fibroblast infiltration and remodelling. Foreign body reactions were visible in both XenoLogiX and PeriGuard, with isolated fibroblast infiltration. PhotoFix showed severe inflammation and 2 implants were completely degraded at 12 weeks.CONCLUSIONS: CardioCel demonstrated optimized physical properties, minimal mineralization potential and superior biocompatibility. These results may benefit the long-term performance of this bioscaffold for cardiovascular surgery. The favourable characteristics of the comparator products were counterbalanced by less desirable features that may have negative implications on durability and performance when used in cardiovascular procedures.

Porcine heart valves and bovine pericardium exhibit suitable properties for use as substitutes in cardiothoracic surgery, but must meet several requirements to be safe and efficient. Treatment with glutaraldehyde (GA) render some of these requirements, but calcification and degradation post-implant remain a problem. This study aimed to identify additional biochemical treatments that will minimize calcification potential without compromising the physical properties of pericardium. Pericardium treated with GA calcified severely after 8 weeks in the subcutaneous rat model, compared to tissue treated with higher concentrations of glycosaminoglycans (GAG) and commercial Glycar patches. GA, lower concentrations GAG and Glycar pericardium had high denaturation temperatures due to enhanced cross-linking. Tensile strength of GA tissue was significantly lower than GAG-treated or Glycar tissues, due to lower water content with resultant lower flexibility and suppleness. Pericardium treated with 0.01 M GAG gave acceptable denaturation temperatures, tensile strength and reduced calcification potential. All tissue treatments evoked comparable host immune responses, and no significant difference in resistance to enzymatic degradation. Ineffective stabilization and fixation of cross-links following GAG treatment, as well as limited penetration into the pericardium, resulted in GAG leaching out into the surrounding host tissue or storage medium, and prohibits safe clinical use of such tissue.

Aortic valves reconstructed with a decellularized pericardial patch demonstrated adequate diastolic function with minimal regurgitation and resistance to calcification. Combining the Ozaki technique with this decellularized pericardial scaffold showed adequate hemodynamics, sustained mechanical integrity of the patch and limited calcification of the material. These results, together with earlier experimental and clinical data, indicate the potential of this material for aortic valve repair.

These findings suggest that diazepam can salvage myocardial function and undo coronary vascular constriction in the endotoxemic rat heart. These findings are clinically relevant to the treatment of cardiovascular depression caused by endotoxic shock.

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