Heterograft valves. An analysis of clinical results of valve replacement

Autografts, homografts, and xenografts: overview on stentless aortic valve surgery

Stentless valves, either human (autografts, homografts) or animal (porcine xenografts), were historically among the first substitutes to be used to replace the diseased aortic valve. Forty years after those pioneering days and 15 years after revival of such valves, stentless grafts have become a mainstay in aortic surgery. Although limitations associated with the use of autografts, homografts and xenografts remain, stentless valves have profoundly improved quality of life after aortic valve/root replacement. In addition, stentless surgery has greatly advanced the understanding of aortic root anatomy, physiology and pathology among surgeons.

The Cryolife-O'Brien stentless aortic porcine xenograft valve

BACKGROUND

The advantageous design of the Cryolife-O'Brien stentless porcine aortic valve permits specific quick, easy, supravalvular implantation using single layer continuous 3-0 polypropylene suture. The advantages, contraindications, and implantation errors to avoid are detailed. The use of this valve for aortic valve replacement in the elderly population has been directed to proving its efficacy and establishing its grounds for durability while maintaining all of the advantages of a stentless tissue valve.

METHODS

From December 1992 to September 1998, this valve was used in 240 patients (mean age 73 years: 15% > 80 years), 45% receiving associated coronary artery grafting (2.4 grafts per patient). Left ventricular (LV) myomectomy was necessary in 12% of patients. Detailed postoperative follow-up (100%) analysis included 650 serial echocardiographic studies.

RESULTS

The 30-day mortality was low at 1.2% (3 deaths of 240 elderly patients). Ten patients had late mortality (1.5 months to 5 years), all nonvalve related. No structural failure and one only explant for endocarditis have occurred. Echocardiographic analyses have shown low mean transvalvular gradients in relationship to time (8.18 mmHg at 18 months) and to valve size (8.52 mmHg for a 23-mm host aortic annulus). Incompetence has been zero or a trace in 97% of the patients at 21/2 years. No patient over the 6 years shows valve deterioration.

CONCLUSION

Six years of experience with this stentless valve in 240 elderly patients has revealed the many advantages of this safe, composite, and truly stentless device that is assembled without the need for Dacron support. Excellent sustained hemodynamics with low gradients, minimal regurgitation, and a good effective orifice have been coupled with low immediate mortality, no intrinsic valve failure, and one explant for endocarditis. Marked LV regression and minimal late valve-related complications confirm the safety and advantages of this stentless valve.