Related Experiment Video
Updated: Aug 14, 2026
An Ex Vivo Porcine Model for Hydrodynamic Testing of Experimental Aortic Valve Procedures and Novel Medical Devices
Published on: August 25, 2023
Factors influencing the mean postoperative gradients across stentless porcine valves
Pallav J Shah1, Brian F Buxton, George Matalanis
1Department of Cardiac Surgery, Austin Hospital, Studley Road, Melbourne, Vic. 3084, Australia.
Background:
To study the preoperative and intraoperative variables influencing the mean post-operative transvalvular gradient across stentless porcine valves.
Methods:
From 1995 to 2002, 84 patients underwent stentless valve insertion. The mean age was 73 years, and 63% were male. The valve pathology was aortic stenosis (AS) in 79%, aortic regurgitation (AR) in 12%, and mixed in 9%. Valve sizes ranged from 21 to 29 with size 27 being most frequent. 54% of patients had concomitant procedures. Patients had at least yearly clinical and echocardiographic follow-up.
Results:
There was no operative mortality. 9.5% of the patients had significant postoperative complications. The average echo interval was 18.6 months (range 1-88). The overall mean transvalvular gradient was 9.88+/-5.67 (SD) mmHg. Variables associated with significantly reduced gradients were: larger valve sizes (p=0.002), younger age (p=0.05), pre-op AR (p=0.008), and increasing post-operative interval (p=0.05). The mean gradients decreased by 0.28 mmHg for each post-operative year. The method of implantation did not significantly affect gradients (p=0.26).
Conclusions:
Excellent mean transvalvular gradients were achieved with stentless valves studied, with a low operative risk. The gradients did not appear to be related to intra-operative factors, suggesting that insertion techniques can be tailored to suit patient conditions and surgeon preferences.
