Is 10 minutes the optimum immersion time in 0.6% glutaraldehyde for human pericardium

Background and aim of the study: Pericardial fixation with 0.6% glutaraldeh yde is usually assessed by measuring the shrinkage temperature of the tissu e: the higher the shrinkage temperature, the greater the degree of cross-li nking induced between collagen molecules. Animal pericardium studies have s hown maximum response to be obtained after brief immersion (10 min). Our ai m was to evaluate the effect of glutaraldehyde immersion time on shrinkage temperature of human pericardium which, to our knowledge, has not yet been studied. Methods: Pericardial strips were harvested from 40 patients undergoing card iac surgery. Time of immersion in glutaraldehyde ranged from 3 min to 6 mon ths. Fresh untreated human pericardium samples were used as controls. The r elationship between shrinkage temperature and time of treatment with glutar aldehyde was studied using a regression analysis. Results: Glutaraldehyde treatment of pericardial tissues caused an increase in shrinkage temperature that was related biphasically to the time of imme rsion in glutaraldehyde. Mathematical expression of this curve permitted gl utaraldehyde immersion time to be evaluated in relation to the degree of op timal shrinkage temperature. The time required for optimal fixation with gl utaraldehyde, as measured by shrinkage temperature, was 100 +/- 0.77 min. Conclusion: Our results suggested that a 10-min exposure to glutaraldehyde was insufficient for 'correct' fixation of human pericardium. Inadequate gl utaraldehyde exposure of human pericardium may explain mid and long-term fa ilures reported with this tissue in cardiac surgery.