Octanediol treatment of glutaraldehyde fixed bovine pericardium: evidence of anticalcification efficacy in the subcutaneous rat model

Objective: Anticalcification strategies of glutaraldehyde-fixed xenograft tissue aim to extract lipids or to neutralize toxic aldehyde residuals. The purposeof this studywasto evaluatethe efficacyof octanediolcompared to standardtreatmentsof glutaraldehyde-fixedbovinepericardium in the subdermal rat model. Octanediol treatment is an ethanolic solution (40%) containing a long chain aliphatic alcohol (5% 1,2-octanediol) that removes lipids without diminishing the stability of collagen. Methods: Octanediol and standard glutaraldehyde fixed bovine pericardium were both implanted in 24 Sprague-Dawley rats, explanted after 30—75 days (12 animals each) and submitted to X-ray (score 0—4), histology, electron microscopy and elemental analysis by spectroscopy (Ca and P content). Unimplanted octanediol and standard glutaraldehyde fixed pericardium servedascontrol.Results:At30daysoctanediol-treatedpericardiumshowedcalciumcontentof0.20 0.1vs20.07 36.79 mg/gdryweightfor standard pericardium. The difference was also evident at 75 days: calcium content of 2.36 7.38 mg/g dry weight for octanediol vs 165.61 23.35 mg/g dry weight for standard (p < 0.0001). Differences were also detected at X-ray (mean score 0.7 0.6 octanediol vs 3.8 0.4 standard at 75 days). Equally, mean P content was 11.69 21.33 mg/g dry weight for standard vs 0.60 1.45 mg/g dry weight for octanediol samples at 30 days, and 90.90 12.61 mg/g dry weight for standard vs 1.42 4.34 mg/g dry weight for octanediol at 75 days (p < 0.0001). At electron microscopy collagen appeared well preserved regardless of the type of treatment; in octanediol treated pericardium cell membranes almost disappeared and only few profiles of endoplasmic reticulum and rare mitochondria were visible. Conclusions: Treatment with octanediol strongly prevents calcification of glutaraldehyde fixed bovine pericardium in rat subdermal model, even in the long-term. Evidence of octanediol efficacy may entail important implications for new generation bioprosthetic valves. # 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.