Percutaneous venous valve bioprosthesis: initial observations

Chronic deep venous insufficiency remains a major health problem in the United States and worldwide. Selected patients benefit from direct deep vein valve repair or valve transplantation; however, most are not candidates for these procedures. Experience with the bovine monocusp venous valve surgically inserted into the common femoral vein (CFV) demonstrates potential benefit and good long-term patency. A venous valve placed distal to the CFV via percutaneous access has great appeal and potential for further improving venous hemodynamics, as well as reducing ambulatory venous hypertension and ulceration. Two patients were treated with a percutaneous venous valve bioprosthesis as part of a Phase I trial. The primary objective was to evaluate the safety, patency, and efficacy of the percutaneous venous valve bioprosthesis to restore competency to the deep venous system.     

Stentless bioprosthesis for aortic valve replacement

The stentless aortic bioprosthesis was reported to reduce left ventricular mass (LVM) in the early period after implantation and have better hemodynamic performance and a larger effective orifice area (EOA) than stented valves. However, its clinical advantage over the stented valve is still unclear. We have implanted stentless bioprostheses in 61 patients and had a low operative mortality rate (1.6%). LVM index, left ventricular end-diastolic volume (LVEDV) index, left ventricular end-systolic volume (LVESV) index, and peak pressure gradient (PG) were rapidly reduced after implantation. Ten-year-freedom from cardiac-related death, thromboemolism, and structural valve deterioration rates were 91.0%, 100%, and 95.0%, respectively. Furthermore, using MRI analysis, blood velocity through stentless valves was similar to that through native aortic valves in comparison with stented valves. In conclusion, the stentless valve enables more physiologic blood flow through the valve, and thus it may be useful in patients with small annuli or those who require better hemodynamic performance to enable physical activity.     

Aspergillus cyst of aortic valve bioprosthesis

Aspergillus endocarditis (AE) is an ominous complication of cardiac surgery with a dismal prognosis. We present a 35-year-old female who developed AE 4 months after her aortic and mitral valve replacement. Transesophageal echocardiography revealed an aortic root abscess and a cystic mass attached to the aortic bioprosthesis. Intraoperatively, the cyst was filled with fungal material. The aortic bioprosthesis was replaced and the patient was treated with amphotericin B. Six weeks later her condition suddenly deteriorated and she died on the same day. Early performance of transesophageal echocardiography and extended blood culture is mandatory in suspected cases of AE.     

Aortic valve replacement with stentless bioprosthesis: operative methods and pitfalls

Operative methods and pitfalls of aortic valve replacement using either Toronto SPV and Freestyle prosthesis were described. Precise transverse aortotomy, straight inflow-suture line, and outflow suture not obstructing coronary orifices are the points for the standard procedure. For bicuspid aortic valves, care should be taken for the anomaly of coronary orifices. Our experience with 24 consecutive cases indicated that oversizing of the prosthesis was possible in stentless bioprosthesis.     

Early bioprosthesis failure in mitral valve replacement

The causes of early bioprosthesis failure include infective endocarditis, pannus formation, and structural valve deterioration. We reported a patient who suffered from early mitral bioprosthesis failure due to leaflets restricted by the subvalvular apparatus and early pannus formation. In patients with symptoms relapse and mitral regurgitation recurrence early after mitral valve replacement, early pannus formation needs to be anticipated, and surgical intervention should be performed if symptoms persist after medical treatment.     

Aortic valve replacement with medtronic freestyle bioprosthesis: operative technique and results

OBJECTIVE: This study evaluates the initial results for safety and efficacy of aortic valve replacement (AVR) using the Medtronic Freestyle Bioprosthesis. METHODS: One hundred three patients underwent AVR with the Medtronic Freestyle Bioprosthesis over a 40-month period. There were 59 male and 44 female patients with a mean age of 74 years (range 36 to 88 years). Valve size ranged from 19 to 27 mm, and all valves were implanted using a freehand subcoronary technique. Anticoagulation with coumadin was only used for atrial fibrillation. Aspirin was given to patients with associated coronary artery disease. Echocardiography to assess transvalvular pressure gradient and effective valve orifice area was performed at discharge, 3 to 6 months, 1 year, and then annually. RESULTS: There were 4 (3.9%) deaths within 30 days of operation and 5 (4.9%) late deaths. Two (1.9%) deaths were valve-related, one from commissural dehiscence and one from bacterial endocarditis. Three (2.9%) deaths, two early and one late, were from other cardiac causes. The remaining deaths were from noncardiac causes. Five (4.9%) patients suffered a thromboembolic event, two had permanent neurological deficits, two had transient neurological events, and one had coronary artery occlusion. Mean transvalvular gradient assessed by echocardiography was low at all time intervals: discharge (12.8 mmHg), 3 to 6 months (11.3 mmHg), 1 year (12.0 mmHg), and 2 years (11.6 mmHg). Mean effective valve orifice area was good at all time intervals: discharge (1.4 cm2), 3 to 6 months (1.5 cm2), 1 year (1.6 cm2), and 2 years (1.6 cm2). Of the 38 patients assessed by echocardiography at 1 year, 33 (87%) had no or trivial valve incompetence and the remainder had mild valve incompetence. CONCLUSIONS: Aortic valve replacement with the Medtronic Freestyle Bioprosthesis has a low incidence of early valve-related mortality and thromboembolism. The bioprosthesis demonstrates good hemodynamic performance even in small diameters and is particularly well suited for older patients and the small aortic root.     

Aortic valve replacement with stentless porcine aortic bioprosthesis

Twenty-nine patients were entered in a clinical trial on aortic valve replacement with a stentless glutaraldehyde-fixed porcine aortic valve. This bioprosthesis is secured to the aortic root by the same technique used for aortic valve replacement with aortic valve homografts. The functional results obtained from this operation have been most satisfactory. To assess the hemodynamic benefit of eliminating the stent of a porcine aortic valve, we matched 22 patients with a stentless porcine bioprosthesis for age, sex, body surface area, valve lesion, and bioprosthesis size to 22 patients who had aortic valve replacement with a Hancock II bioprosthesis. Mean and peak systolic gradients across the aortic bioprosthesis and effective aortic valve areas were obtained by Doppler studies. Gradients across the stentless bioprosthesis were significantly lower than gradients across the Hancock II valve for every bioprosthesis size. Effective aortic valve areas of the stentless bioprosthesis were significantly larger than the valve areas of the Hancock II valve. Our data demonstrate that the hemodynamic characteristics of a glutaraldehyde-fixed porcine aortic bioprosthesis are greatly improved when the aortic root is used as a stent for the valve. This technique of implantation is expected to enhance the durability of the bioprosthesis, because the aortic root may dampen the mechanical stress to which the leaflets are subjected during the cardiac cycle.     

The Freestyle stentless bioprosthesis for prosthetic valve endocarditis

We report a case of methicillin-resistant Staphylococcus aureus-induced prosthetic valve endocarditis, which was successfully treated with aortic valve replacement using the Freestyle stentless bioprosthesis. The total root and stentless design of this bioprosthesis allows for more radical removal of infected tissue and easier treatment for annular abscess, while requiring less prosthetic materials than a conventional prosthesis. This bioprosthesis thus seems to be a valuable option for active endocarditis.