EComment. Autologous pericardium is superior to conventional bovine patch in congenital heart disease reconstructive surgery: an appraisal for tissueengineered xenograft

Abstract

We have read with interest the paper from Neethling et al. about the use of an engineered bovine pericardial patch for reconstructive congenital heart surgery [1]. Congenital heart surgery requires patch material for the reconstruction of vascular structures or restoration of cardiac septation in the vast majority of interventions. From the outset, autologous and xenograft pericardium have been widely used and preferred over prosthetic materials because of their ease in both handling and shaping. Although autologous pericardium is readily available during primary correction of cardiac defects requiring structural reconstruction, in pathologies where staged palliation is planned (e.g. the three-staged palliation of hypoplastic left heart syndrome), a considerable amount of available pericardium is required. Thus, bovine pericardium could provide an off-the-shelf solution with unlimited availability. Accordingly, the bovine pericardial patch has been extensively used over the last years, especially in congenital aortic arch surgery, due to its lower cost and virtual absence of the development of anti-HLA antibodies associated with the use of cryopreserved allograft material, although it was not superior to the other materials in terms of freedom from aortic arch restenosis [2]. The use of bovine pericardium also showed a tendency to be associated with reintervention (HR 1.81; 95% CI: 0.90-3.64) as demonstrated by Ashcraft et al. [3]. A recent comparison of the mechanical properties of materials used in the setting of aortic arch reconstruction, revealed that bovine pericardium is 16.4 times stiffer than the pathological aorta, while fixed human pericardium was only 7.1 times stiffer [4]. It is intuitive that in small calibre vessels, the compliance mismatch between the prosthetic material and the vessel itself could trigger abnormal intimal hyperplasia, eventually leading to restenosis or distortion. In our experience, the use of autologous glutaraldehyde-fixed pericardium showed good results in terms of ease of use and tailoring, its availability even in redo cases, high haemostatic nature and low immunogenicity [5]. In our opinion, an autologous patch must be used when available, while only tissue-engineered bovine pericardium, as reported by Neethling et al. should be used, in order to minimize its aforementioned intrinsic problems. Conflict of interest: none declared