HHP-Decellularized Porcine ITA for CABG: Preserved Compliance and In Vitro Hemocompatibility

Small-diameter conduits for coronary artery bypass grafting (CABG) require both distensibility and hemocompatibility, but synthetic grafts have poor patency. We evaluated an acellular arterial conduit prepared from porcine internal thoracic arteries (ITAs) harvested with an ultrasonic (harmonic) scalpel and decellularized by high hydrostatic pressure (HHP). Porcine ITA was decellularized at 600 MPa and washed with DNase I and ethanol. Extracellular matrix preservation and residual DNA were assessed by histology/SEM and DNA quantification. Mechanical performance was evaluated using ISO 7198-guided methods, including suture retention, integral leakage, kink radius, and static compliance. Kink radius was measured under luminal pressurization using a cylindrical taper gauge, and static compliance was calculated as diameter-based compliance from the reconstructed inner radius under stepwise pressurization and reported as %/100 mmHg. In vitro hemocompatibility was assessed in an ISO 10993-4-guided closed-loop blood circulation assay (4 h, 37°C) by measuring TAT, β-thromboglobulin, SC5b-9, and hematology parameters. HHP decellularization removed cellular components while preserving arterial microarchitecture and reduced residual DNA to 8.1 ± 2.7 ng/mg dry tissue. The grafts maintained pressure-dependent, nonlinear diameter-based compliance comparable with native porcine ITA and showed no detectable integral leakage, including sealed branches, up to 200 mmHg under the present conditions. Mean kink radius at the onset of kinking was 6.9 mm for decellularized ITA and 6.3 mm for native ITA. Blood-contact testing showed activation of coagulation, platelet, and complement pathways comparable with the blank loop under heparinized closed-loop conditions and far below positive controls. These findings support the further development of HHP-decellularized porcine ITA as compliant conduits for CABG and warrant in vivo evaluation of patency and remodeling.Impact StatementOff-the-shelf small-diameter coronary artery bypass grafts require compliance, kink resistance, and hemocompatibility. We combine ultrasonic (harmonic) scalpel harvest (simultaneous branch sealing) with 600-MPa high hydrostatic pressure decellularization without detergents to produce a stockable porcine internal thoracic artery scaffold. ISO 7198-guided tests show no leakage from sealed branches, low kink radius, and preserved pressure-dependent, nonlinear diameter-based compliance. ISO 10993-4-guided human blood circulation indicates coagulation, platelet, and complement activation comparable with the blank (negative) loop under heparinized closed-loop conditions, and markedly lower than positive controls. This workflow provides a rationale for in vivo patency and remodeling studies.