Replacement of the aortic valve and ascending aorta with a valved stentless composite graft: technical considerations and early clinical results

Utilizing a sutureless valve for prosthetic valve endocarditis after aortic root replacement

BACKGROUND

Reoperation following aortic root replacement is associated with significantly high operative mortality. Etiologies related to infection are known to increase the operative mortality rate more than other etiologies. In such a clinical setting, a sutureless valve could lower the operative mortality by shortening the cardiac arrest and the operative time.

CASE PRESENTATION

A 61-year-old male underwent emergent aortic root and total arch replacement with an open stent graft for acute type-A aortic dissection. A bioprosthetic valve was employed for aortic root replacement using the double-sewing ring technique. A fungal infection by Candida parapsilosis was postoperatively detected and improved with intravenous antifungal drug administration. However, he developed congestive heart failure one year later, and the blood cultures turned positive repeatedly for Candida parapsilosis. The prosthetic valve infection was suspected upon identifying vegetation on the bioprosthetic valve through transthoracic echocardiography. The computed tomography scan and operative findings confirmed that the infection was localized on the prosthetic valve. Consequently, the infected valve was removed without a vascular conduit, and a sutureless valve was implanted. The postoperative course was uneventful, without any evidence of recurrent fungal infection, and the patient was discharged on postoperative day 28.

CONCLUSIONS

Deploying a sutureless valve can facilitate a more straightforward and minimally invasive redo procedure. Preoperative computed tomography can predict the valve size, which is the key to implanting a sutureless valve successfully after the modified Bentall procedure.

Early results of Bentall-type operations during the last 10 years: comparison of mechanical valves and stentless bioprostheses

OBJECTIVE. Various types of prostheses have been used for combined diseases of the aortic root and ascending aorta.

METHODS

All Bentall-type operations (n=64) between 1996 and 2005 were retrospectively studied, comparing different types of prosthesis in the aortic position. The patients were 29-87 years old (mean 59.5 +/- 14.0 years) and included 47 men and 17 women. Mechanical valves, stentless bioprostheses (Freestyle), stented bioprostheses, and a homograft were used in 31, 29, 3, and I patients, respectively. Early results, especially hemodynamics, were analyzed among two groups: mechanical valve group (M-group) and Freestyle group (F-group).

RESULTS

The average age was significantly higher in the F-group (62.8 +/- 12.7 years) than in the M-group (54.9 +/- 14.0 years) (P = 0.025). The implanted valve was significantly larger in the F-group (26.0 +/- 2.3 mm) than in the M-group (23.5 +/- 2.1mm) (P = 0.000). The estimated effective orifice area of the prosthesis was significantly larger in the F-group (2.23 +/- 0.38 cm2) than in the M-group (1.84 +/- 0.49 cm2) (P = 0.001). The pressure gradient across the prosthesis was significantly lower in the F-group (18.6 +/- 5.5 mmHg) than in the M-group (25.4 +/- 7.6 mmHg) (P = 0.001).

CONCLUSION

The Bentall-type procedure using the Freestyle valve has an advantage regarding hemodynamics compared to the procedure employing mechanical prostheses.

Valved stentless composite graft: clinical outcomes and hemodynamic characteristics

BACKGROUND

The valved stentless composite graft has become well established in our hospital for replacement of the ascending aorta and aortic valve in elderly patients and those with contraindication for lifelong anticoagulation. This study was conducted to evaluate the postoperative hemodynamic characteristics and clinical outcomes after implantation of this device.

METHODS

Between November 1998 and February 2001, 45 consecutive patients with a mean age of 69 years underwent implantation of a composite graft using a stentless valve prosthesis (Toronto SPV) incorporated in a collagen-coated Dacron tube (InterGard). The indication for surgery was aortic valve disease with an accompanying true aneurysm of the ascending aorta in 42 patients and a dissection of the aortic wall in 3 patients. Postoperative echocardiographic examinations were performed before discharge from the hospital and at the time of the follow-up. Mean follow-up duration was 18 months (range 3 to 30 months).

RESULTS

There was no perioperative mortality. During follow-up, there were two noncardiac, nonvalve-related deaths. Echocardiographic evaluation before discharge and at follow-up demonstrated favorable hemodynamics of the valve prosthesis with mean transvalvular gradients of 8.5 +/- 2.9 mmHg and 8.0 +/- 3.1 mmHg, respectively. No regurgitation across the valve and no contact of the cusps with the Dacron tube were seen in any case.

CONCLUSIONS

A stentless composite graft for replacement of the aortic valve and ascending aorta offers excellent hemodynamic results and is a suitable device for patients in whom anticoagulation should be avoided.

Five-year experience in aortic root replacement with the flanged composite graft

BACKGROUND

Replacement of the aortic root with a composite graft containing a prosthetic mechanic valve is the preferred surgical procedure for tailoring the aortic root. The aim of this study is to determine the 5-year experience with the composite root replacement using our new modification of the Bentall technique.

METHODS

Between January 1996 and June 2001, 96 patients underwent aortic root replacement using a flanged composite graft. Eighty patients (83.3%) were male, and 16 patients (16.7%) were female with a mean age of 48.7 +/- 14.4 years. Indications for operation were a true or false aneurysm (65.6%), severe calcified aortic valve stenosis (4.2%) or severe aortic insufficiency (2.1%) with dilated ascending aorta, acute dissection (2.1%), or combination of indications (26%). Thirty-one patients (32.3%) received a concomitant cardiac procedure. Mean aortic cross-clamp time was 89.5 +/- 28.6 minutes, and mean cardiopulmonary bypass time was 146.2 +/- 45.6 minutes. Total follow-up was 253.9 patient-years.

RESULTS

Operative mortality was 8.3% (8 patients). The causes of hospital mortality were severe bleeding (3 patients), low cardiac output syndrome (2), acute respiratory distress syndrome (2) and cerebrovascular event (1). No patient died of flange-related complications. Univariate predictors of early mortality were low cardiac output syndrome (p < 0.001), neurologic complication (p = 0.03), and renal complication (p = 0.03). Multivariate analysis demonstrated only low cardiac output syndrome to be significant (p = 0.001) predictor for early mortality. There were five (5.7%) late deaths. Actuarial survival was 82.65% +/- 4.8% at 5 years (1.95% patient-year). Cox proportional hazards regression analysis demonstrated only low cardiac output syndrome to be significant (p = 0.032) predictor for late mortality. Actuarial freedom from prosthetic- and technique-related mortality was 100% at 5 years.

CONCLUSIONS

The flanged composite graft offers excellent long-term results, with very low prevalence of prosthetic-related complications. The new created sinuses and the flange are especially helpful to continue physiologic function of the aortic root.

Complete aortic root replacement in patients with small aortic annulus

BACKGROUND

We evaluated the effectiveness of our surgical method using a modified self-assembled valved composite graft in patients with a narrow aortic annulus.

METHODS

Between August 2000 and May 2001, 10 consecutive patients with a narrow aortic annulus underwent replacement of the aortic valve and the ascending aorta using a valved composite graft with mechanical valve prosthesis. The indication for surgery was aneurysm of the ascending aorta (8 patients) and aortic dissection (2 patients). To avoid valve-patient mismatch, a modified self-assembled valved composite graft was used.

RESULTS

There was no hospital mortality. Echocardiographic evaluation before discharge showed excellent hemodynamics with a mean transvalvular gradient of 10.7 mm Hg (standard deviation +/- 2.8 mm Hg).

CONCLUSIONS

The described valved composite graft offers very good hemodynamic performance and is a simple and effective device to avoid valve-patient mismatch in patients with a small aortic annulus who need aortic root replacement.

Composite stentless valve with graft extension for combined replacement of the aortic valve, root and ascending aorta

OBJECTIVE

The composite mechanical valve conduit has been most commonly used for patients who require combined aortic valve, root, and ascending aorta replacement, but is limited, especially in the elderly, because of the need for long-term anticoagulation. We report the first consecutive series of patients in whom a composite stentless valve with graft extension, which does not require long-term anticoagulation, was performed.

METHODS

Between April 1998 and July 2000, eight patients with severe aortic root and ascending aortic pathology underwent a combined aortic valve, root, and ascending aorta replacement with a Freestyle stentless porcine valve with a Hemashield graft extension. Mean age was 74 (range 56--82), three were males. Concomitant procedures included coronary artery bypass graft (CABG) alone (n=2), mitral valve replacement with atrial septal defect repair (n=1) and CABG with septal myomectomy (n=1).

RESULTS

Operative mortality was zero. Median aortic cross-clamp and cardiopulmonary bypass times were 150 and 203 min, respectively. Two patients returned to the operating room for bleeding. Median blood transfusions and hospital length of stay were 4 units and 11 days, respectively.

CONCLUSIONS

The composite stentless valve with graft extension is a reasonable alternative to a mechanical valve conduit for patients who require a combined aortic valve, root, and ascending aorta replacement, in whom anticoagulation is not desirable or contraindicated.