Rapid versus slow degeneration and complications of biomaterials in patients with congenital heart disease.

OBJECTIVES

Re-operations due to material degeneration carry a burden for patients with congenital heart disease (CHD). The study aim was to compare rapid vs. slow degeneration of biomaterials in CHD patients.

METHODS

Explants from re-operations of 29 CHD patients (2015-2022) were grouped according to the duration of implantation (short implantation < 3 years (n = 16) vs. long implantation 10-15 years (n = 13)). Histologic processing and staining allowed tissue and calcification analysis. Micro-X-ray fluorescence (µXRF) was used for elemental analysis. Semi-quantitative comparison of calcium was conducted using a self-developed software.

RESULTS

Thrombosis was recurrently observed in short-implanted RVOT samples. 62.5 % (n = 10) of short-implanted samples showed calcification in Alizarin red staining, in comparison to 69.2 % (n = 9) in the long-implanted group. µXRF analysis revealed calcium deposits in all patients, mostly co-localized with phosphorus. In the short implant group, other detected elements included iron, chlorine, chromium, nickel, titanium and zinc. In the long implant group, iron, nickel, titanium, zinc, copper and iodine were found. No significant difference in calcification (Ca-Si-ratio) between both implantation groups (p = 0.083) was found.

CONCLUSION

Thrombus formation is a main rapid degeneration cause in the RVOT. Deteriorations of biomaterials in CHD patients show strong parallels to bioprosthetic valve degenerations. Early calcification in young patients is supported by our semi-quantitative calcium analysis. The role of other elements in graft degeneration remains to be assessed in the future.