In vitro modeling of crimped Dacron vascular grafts for aortic root replacement.

Objective: To objectively quantify the effect of flattening the crimps in Dacron tube grafts on the radial compliance under pulsatile pressure. We aimed to minimize the dimensional changes in woven Dacron graft tubes by applying axial stretch to the graft. We hypothesize this might reduce the risk of coronary button misalignment in aortic root replacement.

Methods: In an in vitro pulsatile model that delivered systemic circulatory pressures to Dacron tube grafts, we measured oscillatory movements in 26-30 mm Dacron vascular tube grafts before and after flattening the graft crimps. We also describe our surgical methods and clinical experiences in replacing the aortic root.

Results: Flattening the crimps in Dacron tubes with axial stretching significantly reduced the mean maximal oscillation distance measured radially during each balloon pulse (3.2 ± 0.8 mm, 95% CI: 2.6, 3.7 mm vs. 1.5 ± 0.5 mm, 95% CI: 1.2, 1.7 mm; P < 0.001).

Conclusion: The radial compliance of woven Dacron tubes was significantly reduced after flattening the crimps. Applying axial stretch to the Dacron grafts prior to determining the coronary button attachment site can help maintain dimensional stability in the graft, which may reduce the risk of coronary malperfusion in aortic root replacment.