Aortic allografts and pulmonary autografts for replacement of the aortic valve and aortic root

Long-term results after aortic root replacement using self-assembled valve composite grafts in patients with small aortic annulus

OBJECTIVES

The study was aimed to evaluate operative and long-term results after complete root replacement using self-assembled valve composite grafts in patients with a small aortic annulus.

METHODS

Among 547 consecutive patients who received the Bentall procedure between 2000 and 2012, a total of 29 patients (61 ± 10; range 42-79 years) had an annulus of ≤20 mm (mean 19.0 ± 0.9). Patients with a native aortic valve (22) suffered from stenosis, insufficiency or mixed defect in 10, 10 and 2 cases, respectively. Among the remaining 7 patients with an artificial aortic valve, there were 3 symptomatic prosthesis-patient mismatches, 3 valve prosthesis deteriorations (1 structural and 2 none-structural) and 1 paravalvular leak. Indication for aortic root replacement was true or false aneurysm, porcelain aorta and intraoperative aortic wall injury in 17, 6 and 6 patients, respectively.

RESULTS

The composite graft for complete aortic root replacement was assembled using a mechanical (26) or biological (3) valve prosthesis placed inside a vascular graft with a median size of 24 (range 22-26) mm. The margin of the tube beneath the valve was anastomosed to the aortic annulus, and coronary ostia were implanted in the usual manner. The mean transvalvular gradient at discharge was 10.8 ± 3.9 mmHg and remained virtually unchanged at the follow-up completed for all patients. Early mortality was 0. During the mean follow-up of 95.8 ± 43.7 months, 2 patients died (54 and 146 months after surgery) due to pulmonary embolism and myocardial infarction, respectively.

CONCLUSIONS

In patients with a small aortic annulus who need complete aortic root replacement, an oversizing of the valve can be easily achieved using modified, self-assembled composite grafts. Offering excellent haemodynamic characteristics, these grafts lead to prevention of prosthesis-patient mismatch and result in very good and durable functional and clinical results.

Ross operation in a patient with juvenile rheumatoid arthritis

A 32-year-old woman with juvenile rheumatoid arthritis underwent a redo aortic valve replacement 7 years after a Ross procedure for severe aortic valve regurgitation. Interestingly, the cause of autograft failure was not related to the rheumatoid inflammation process.

Allogenic heart valve bank in the Department of Cardiovascular Surgery and Transplantology of Jagiellonian University in Cracow - 23 years experience in the treatment of aortic valve or aortic root diseases

Allogenic aortic valves are widely used in case of native aortic valve or root disease as well as failed prosthetic valves with great success. At the Department of Cardiovascular Surgery and Transplantology of the Jagiellonian University in Cracow, aortic valve or aortic root replacement with allogenic aortic valve has been performed for 23 years. Allogenic heart valve bank was founded in 1980. In the bank we prepare both aortic allografts for adult cardiac surgical procedures and pulmonary allografts that are mostly used for repair of congenital heart disease.Allogenic aortic valves implantation was usually considered in our clinic for older patients, patients with infective endocarditis of the native or prosthetic valve, young women in reproductive age and patients with Marfan syndrome. Allografts exhibit excellent clinical performance and acceptable durability with no early failure if properly inserted. Between 1980 and 1992, allografts were obtained only from cadavers during routine autopsies. More than 10% of prepared allografts were exported to other cardiac surgery centres in Poland and foreign countries. Aortic valve replacement using allogenic aortic valves can be performed with acceptable mortality and good long-term results. The procedure although surgically more challenging has the advantage of not requiring anticoagulation therapy, hemodynamic performance of the allogenic valve is excellent, it demonstrates freedom from thromboembolism and infective endocarditis. We would like to emphasize the importance and advantages of the fact that allogenic heart valve bank is placed in the department of cardiovascular surgery and it is able to supply the department in heart valve allografts 24 h a day.

Do pulmonary autografts provide better outcomes than mechanical valves? A prospective randomized trial

BACKGROUND

The objective of this study was to compare the performance of pulmonary autografts with mechanical aortic valves, in the treatment of aortic valve stenosis.

METHODS

Forty patients with aortic valve stenoses, and below the age of 55 years, were randomly assigned to receive either pulmonary autografts (n = 20) or mechanical valve (Edwards MIRA; Edwards Lifesciences, Irvine, CA) prostheses (n = 20). Clinical outcomes, left ventricular mass regression, effective orifice area, ejection fraction, and mean gradients were evaluated at discharge, 6 months, and one year after surgery. Follow-up was complete for all patients.

RESULTS

Hemodynamic performance was significantly better in the Ross group (mean gradient 2.6 mm Hg vs 10.9 mm Hg, p = 0.0005). Overall, a significant decrease in left ventricular mass was found one year postoperatively. However, there was no significant difference in the rate and extent of regression between the groups. There was one stroke in the Ross group and one major bleeding complication in the mechanical valve group. Both patients recovered fully.

CONCLUSIONS

In our randomized cohort of young patients with aortic valve stenoses, the Ross procedure was superior to the mechanical prostheses with regard to hemodynamic performance. However, this did not result in an accelerated left ventricular mass regression. Clinical advantages like reduced valve-related complications and lesser myocardial strain will have to be proven in the long term.

The Ross Operation: An Evaluation of a Single Institution's Experience

BACKGROUND

Pulmonary autograft aortic root replacement was used in adults. Risk factors for aortic valve incompetence (AI) and pulmonary homograft valve stenosis are identified.

METHODS

From February 1991 through May 2003, 103 patients, with a mean age of 35.2 +/- 9.5 years, underwent aortic root replacement with the pulmonary autograft. Annulus reinforcement (reduction annuloplasty or use of root ring) was carried out in 45 patients. In all but 1 patient, the right ventricular outflow tract was reconstructed with a cryopreserved pulmonary homograft. Mean follow-up duration was 6.0 +/- 2.8 years (range 0.3 to 11 years).

RESULTS

There were no hospital deaths. Overall patient survival was 98.9 +/- 1.0% at 1 year and 97.3 +/- 1.9% at 10 years. Autograft function follow-up resulted in 5 patients requiring reoperation for aortic incompetence. The univariate risk factors for aortic incompetence at discharge and during follow-up were respectively annulus reinforcement (p = 0.05) and bicuspic aortic valve (p = 0.05). Reoperation for homograft failure occurred in 1 patient. During follow-up, 24 patients (25.5%) developed homograft stenosis (gradient > 20 mm Hg). Univariate analysis indicated the diameter of the homograft (p = 0.001) as factor associated with stenosis during follow-up. Cox regression identified smaller diameter of the homograft (p = 0.001) and older age of donor (p = 0.002) as independent risk factor for the development of homograft stenosis.

CONCLUSIONS

The Ross operation can be performed with few complications. Although both the aortic autograft and the pulmonary homograft have limited durability, this has not yet resulted in considerable reoperation rates and associated morbidity and mortality.

Newer concepts in the surgical treatment of valvular heart disease

The search for the ideal therapy for valve replacement continues. The major options include mechanical or tissue valves, with an increasing variety of tissue valves becoming available. The key factor continues to be thrombogenicity versus durability. Aortic valve surgery primarily consists of replacement. This is aided by the increased variety of options allowing tailoring of the procedure to the patient's native valve disease. Mitral valve surgery has greater potential for repair, which affords preservation of the native valve, optimizing function and reducing long-term complications. An increasingly popular concept is treatment of secondary or functional mitral valve regurgitation in the setting of depressed left ventricular function. The routine use of intraoperative transesophageal echocardiography and a trend toward the use of minimally invasive procedures are altering the conduct of valve operations.

Aortic valve disease with severe ventricular dysfunction: stentless valve for better recovery

BACKGROUND

Stentless bioprostheses and homografts show better hemodynamic profiles compared with conventional stented bioprostheses and mechanical valves. Few data are available on stentless aortic valve implantation for patients with severe left ventricular dysfunction. The aim of this retrospective study was to assess the potential benefits of stentless aortic valve implantation for patients undergoing isolated aortic valve replacement with left ventricular ejection fraction < or = 35%.

METHODS

From November 1988 through March 2000, 53 patients (45 men and 8 women, aged 64.2 +/- 15.2 years) with a LVEF < or = 35% (mean EF, 28.7 +/- 5.4%) underwent isolated, primary aortic valve replacement for chronic aortic valve disease. Twenty patients received stentless aortic valves and 33 patients received conventional stented bioprostheses and mechanical valves. Predictive factors for LVEF recovery at echocardiographic follow-up (36.2 +/- 32.1 months) were analyzed by simple and multiple regression analysis.

RESULTS

There were no significant differences between groups in early and late mortality. Stentless aortic valve implantation required a longer aortic cross-clamp time (p = 0.037). The stentless aortic valve group showed a better LVEF recovery (p = 0.016). Stentless aortic valves had a larger indexed effective orifice area compared with conventional stented bioprostheses and mechanical valves (p < 0.0001). A smaller indexed effective orifice area (p = 0.0008), chronic obstructive pulmonary disease (p = 0.015), and implantation of a conventional stented bioprosthesis or mechanical valve (p = 0.016) were related to reduced LVEF recovery by univariate analysis. A larger indexed effective orifice area (p = 0.024) was an independent predictive factor for a better LVEF recovery by multivariate analysis.

CONCLUSIONS

Stentless aortic valve implantation for patients with severe left ventricular dysfunction, even if technically more demanding, is a safe procedure that warrants a larger indexed effective orifice area leading to an enhanced LVEF recovery.

Update on indications for surgery in aortic insufficiency

Aortic insufficiency is a valvular disease characterized by left ventricular volume overload. This article presents a logical approach for following up patients with aortic insufficiency and helps to determine the optimal timing for valve replacement. The various valve replacement techniques are discussed, and the specific benefits or risks associated with these procedures are described.

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.