The Carpentier-Edwards stented supra-annular pericardial aortic valve prosthesis: clinical durability and hemodynamic performance

Modified Bentall operation: the double sewing ring technique

The Bentall-DeBono operation is the technique of choice for aortic root replacement. As more patients do not accept or have contraindications to lifelong anticoagulation, the biological Bentall operation is a good option for these patients, even though complex reoperations would then be required for bioprosthesis degeneration. We studied a modified technique to simplify the reoperations in patients undergoing biological Bentall procedure. A bioprosthetic valved conduit was obtained creating two separate sewing rings at different levels of the vascular graft. One ring was used to sew the bioprosthesis on the vascular graft. The second ring was used to fix the vascular graft on the native aortic annulus. In case of reoperation, the bioprosthesis could be removed cutting only the suture on the first ring. Then the same ring could be used to fix the new prosthesis. Since 2006, we have performed 12 biological Bentall operations with our modification. The mean age was 63.2 years (range 43-77 years), the mean cardiopulmonary time was 79+/-12 min and the mean aortic cross-clamping time was 68+/-10 min. We had no in-hospital mortality; the postoperative period was uneventful in all patients. In our experience this modification seems to be simple and reproducible, without increasing the operative risk and postoperative morbidity.

Glutaraldehyde exposures among workers making bioprosthetic heart valves

Exposure to glutaraldehyde is a recognized cause of work-related asthma. An investigation was undertaken to describe exposure to glutaraldehyde among workers making bioprosthetic heart valves and to make recommendations for prevention. At the two largest heart valve manufacturing facilities in California, the work process was observed; employer representatives and glutaraldehyde-exposed workers were interviewed; and employer written records, including company-generated industrial hygiene data, were analyzed. Approximately 600 female workers had continuous airborne exposure to glutaraldehyde over the course of every work shift and the routine potential for skin and eye contact with glutaraldehyde while making heart valves. Employee short-term (15-min) glutaraldehyde exposures were all well below the current regulatory ceiling level (0.20 ppm). Overall, approximately 40% of the glutaraldehyde-related job tasks involved exposures above the American Conference of Industrial Hygienists threshold limit value ceiling of 0.05 ppm; the majority (71.4% and 83.3%, depending on the company) involved exposures greater than 0.015 ppm. At one company, two cases of physician-diagnosed asthma were recorded by the employer in the previous 5-year period; these reports met the surveillance case definition for new-onset, work-related asthma associated with a known asthma inducer. Factors that contributed to worker exposure included large exposed surface areas of glutaraldehyde under agitation; working with glutaraldehyde-treated tissue in proximity to workers' breathing zones; manual pouring and disposal of glutaraldehyde solutions without local exhaust ventilation, eye protection, and waste neutralization; and prolonged use of latex gloves. Workers making bioprosthetic heart valves are at risk for occupationally acquired asthma. Employers should implement additional engineering controls to minimize workers' exposures to at least below a level of 0.015 ppm, an appropriate glove to prevent workers' skin exposure to glutaraldehyde, consistent and universal use of eye protection, and a medical surveillance program for glutaraldehyde-exposed workers.

Prognosis After Aortic Valve Replacement With the Carpentier-Edwards Pericardial Valve: Use of Microsimulation

BACKGROUND

The second-generation Carpentier-Edwards pericardial valve (Edwards Lifesciences LLC, Irvine, CA) is widely used for aortic valve replacement. However, knowledge on the long-term outcomes of patients after valve implantation is incomplete. We used microsimulation to calculate the long-term outcome of any given patient after aortic valve replacement with the Carpentier-Edwards pericardial valve.

METHODS

A meta-analysis of 8 reports on aortic valve replacement with the Carpentier-Edwards pericardial valve (2,685 patients; 12,250 patient years) was used to estimate the hazards of valve-related events other than structural valvular deterioration. Structural valvular deterioration was described by age-dependent Weibull curves calculated from 18-year follow-up, premarket approval, Carpentier-Edwards pericardial primary data. These estimates provided the input data for the parameters of the microsimulation model, which was then used to calculate the outcomes of patients of different ages after valve implantation. The model estimates of survival were validated using two external data sets.

RESULTS

The Weibull analysis estimated a median time to reoperation for structural valvular deterioration ranging from 18.1 years for a 55-year-old male to 23.2 years for a 75-year-old male. For a 65-year-old male, microsimulation calculated a life expectancy and event-free life expectancy of 10.8 and 9.1 years, respectively. The lifetime risk of at least one valve-related event was 38% and that of reoperation due to structural valvular deterioration 17%, respectively, for this patient. The model estimates of survival showed good agreement with external data.

CONCLUSIONS

Microsimulation provides detailed insight into the long-term prognosis of patients after aortic valve replacement. The Carpentier-Edwards pericardial valve performs satisfactorily and offers a low lifetime risk of reoperation due to structural valvular deterioration, especially for elderly patients requiring aortic valve replacement.

Bioprosthetic valved conduit aortic root reconstruction: the Mount Sinai experience

BACKGROUND

Patients requiring aortic root reconstruction who are deemed unable to take anticoagulants offer unique challenges to the surgeon. For these patients, we have been manufacturing composite conduits intraoperatively using stented bioprostheses.

METHODS

During the 10-year period from April 1992 until May 2002, 141 patients (105 male, 36 female) from 34 to 88 years of age underwent aortic root reconstruction with biological valved conduits. Diagnoses included dissection (n = 28, 9 acute type A), degenerative (64), atherosclerotic (32), anuloaortic ectasia (9), endocarditis (5), and other causes (3). Preoperative risk factors included hypertension (90), smoking (63), coronary artery disease (48), and diabetes (6). Valved conduits were mainly constructed from pericardial valves and impregnated Dacron grafts. Distal anastomosis was performed open in all cases except 6; the ascending aorta only was replaced in 63 patients, a hemiarch reconstruction was used in 71, and more extensive arch reconstruction in 7. Additional cardiac procedures were performed in 59 patients.

RESULTS

Two deaths occurred in the operating room (biventricular failure). Late hospital mortality was 11 of 141 (7.8%) of which 6 (55%) were cardiac, 2 (18.2%) were infectious, 2 (18.2%) were of other complications and 1 (9.1%) was unknown. Three patients (2.1%) sustained permanent and 3 transient strokes. No structural deterioration of the valve and an approximately 86% freedom from thromboembolic events was observed during 5 years.

CONCLUSIONS

For patients for whom anticoagulation is contraindicated or undesirable, reconstruction of the aortic root with a stented bioprosthetic valved conduit offers an acceptable alternative to mechanical prostheses.