Michael P. Holden

Fifteen-year experience with the mitral Carpentier-Edwards PERIMOUNT pericardial bioprosthesis

BACKGROUND This multicenter study concerning the mitral PERIMOUNT valve previously reported clinical results at 12 years; this report updates the performance to 15 years postoperatively. METHODS The 435 patients (mean age 60.7+/-11.6 years; 41.1% male) underwent implantation with the PERIMOUNT valve between 1984 and 1989 at seven institutions. Follow-up was complete for 96.1% of the cohort. The mean follow-up was 8.1+/-4.4 years (range 0 to 15.4 years) for a total of 3492 patient-years. RESULTS There were 34 (7.8%) operative deaths, one (0.2%) valve related. The late mortality rate was 5.3%/patient-year (2.2%/patient-year valve related). At 14 years, the overall actuarial survival rate was 37.1%+/-3.3% (63.1%+/-4.4% valve related). Actuarial freedom from complications at 14 years was as follows: thromboembolism, 83.8%+/-3.2% (1.1%/patient-year); hemorrhage, 86.6%+/-3.2% (1.1%/patient-year); and explant due to structural valve deterioration (SVD), 68.8%+/-4.7%. Actual freedom from explant due to SVD was 83.4%+/-2.3%. Rates of structural failure decreased with increasing age at implant. CONCLUSIONS The Carpentier-Edwards PERIMOUNT Pericardial Bioprosthesis is a reliable choice for a tissue valve in the mitral position, especially in patients more than 60 years of age.

Structural valve deterioration in mitral replacement surgery: comparison of Carpentier-Edwards supra-annular porcine and perimount pericardial bioprostheses.

BACKGROUND Bioprostheses preserved with glutaraldehyde, both porcine and pericardial, have been available as second-generation prostheses for valve replacement surgery. The performance with regard to structural valve deterioration with the Carpentier-Edwards supra-annular (CE-SAV) porcine bioprosthesis and the Carpentier-Edwards Perimount (CE-P) pericardial bioprosthesis (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) was evaluated to determine whether there was a difference in mitral valve replacement. METHODS The CE-SAV bioprosthesis was implanted in 1266 overall mitral valve replacements (isolated mitral, 1066; mitral in multiple, 200) and the CE-P bioprosthesis in 429 overall mitral valve replacements (isolated mitral, 328; mitral in multiple, 101). The mean age of the CE-SAV population was 64.2 +/- 12.2 years and that of the CE-P population, 60.7 +/- 11.7 years (P =.0001). For the study, structural valve deterioration was diagnosed at reoperation for explantation. RESULTS The freedom from structural valve deterioration was evaluated to 10 years, and the freedom rates reported are at 10 years. For the overall mitral valve replacement groups, the actuarial freedom from deterioration was significant (P =.0001): CE-P > CE-SAV for 40 years or younger, 80% versus 60%; 41 to 50 years, 91% versus 61%; 51 to 60 years, 84% versus 69%; 61 to 70 years, 95% versus 75%. The older than 70-year group was 100% versus 92% (no significant difference). The actual freedom from structural valve deterioration also demonstrated the same pattern at 10 years: 40 years or younger, CE-P 82% versus CE-SAV 68%; 41 to 50 years, 92% versus 70%; 51 to 60 years, 90% versus 80%; 61 to 70 years, 97% versus 88%; and older than 70 years, 100% versus 97%. The independent risk factors of structural valve deterioration for the overall mitral valve replacement group were age and age groups and prosthesis type (CE-SAV > CE-P). The prosthesis type either in isolated replacement or in multiple replacement was not predictive of structural valve deterioration. The pathology of structural valve deterioration was different: 70% of CE-P failures were due to calcification and 57% of CE-SAV failures were due to combined calcification and leaflet tear. CONCLUSION The actuarial and actual freedom from structural valve deterioration, diagnosed at reoperation, is greater at 10 years for CE-P than for CE-SAV bioprostheses. The mode of failure is different, and the cause remains obscure. Long-term evaluation is recommended, because the different modes of failure may alter the clinical performance by 15 and 20 years.

A clinical evaluation of the performance characteristics of one membrane and five bubble oxygenators: gas transfer and gaseous microemboli production

The gas transfer characteristics and gaseous microemboli (GME) production of five different bubble oxygenators (Polystan Venotherm, Harvey H-1700, Bentley BIO-10, Gambro 10 and Shiley S-100A HED) and one membrane oxygenator (Cobe CML) have been assessed during standardized clinical perfusion for open-heart surgery in 60 adult patients. The perfusionist attempted to maintain physiological levels of PaCO 2 (5 ± 1 kPa) and PaO2 (12 ± 2 kPa). Only 3% of blood gas values were within the normal range in the Bentley BIO-10 group compared with 17% for the Gambro 10, 20% for the Shiley S-100A HED, 31% for the Polystan Venotherm, 33% for the Cobe CML and 36% for the Harvey H-1700. The number of GME detected in the arterial line was significantly lower in the Cobe CML membrane oxygenator when compared with any of the five different bubble oxygenators (p < 0·001). The Polystan Venotherm released significantly less GME (p < 0·02) than the other oxygenators and the Shiley S-100A HED released significantly more GME (p < 0·02) than the other oxygenators except the Gambro 10. Low gas-blood flow ratios were not necessarily associated with low GME levels and inadequate oxygenation. This study provides meaningful data on which to base the choice of oxygenator, for clinical perfusions.

Clinical and hemodynamic evaluation of small perimount aortic valves in patients aged 75 years or older

BACKGROUND There is the potential for iatrogenic aortic stenosis and poor quality of life when small aortic valve bioprostheses are used in elderly patients. The alternative is enlarging the aortic annulus to accommodate larger size prostheses, increasing operative mortality. It was hoped that bovine pericardial valves would improve hemodynamic performance in the smaller valve sizes. METHODS To determine long-term results and in vivo hemodynamic performance of small-size aortic Carpentier-Edwards bovine pericardial valves (Perimount) in elderly patients, we analyzed our follow-up and echocardiographic data from patients 75 years of age or older receiving isolated 19-mm and 21-mm Perimount valves. Ninety-four patients with a mean age of 77 +/- 2.2 years were followed for 12 years. Seventeen patients with 19-mm and 25 patients with 21-mm Perimount valves underwent transthoracic echocardiograms. RESULTS Operative mortality was 6.3% (6 of 94). Twelve-year survival was 82.7%. Freedom from thromboembolism was 86.9% at 12 years. Two patients had anticoagulation-related bleeding. Overall New York Heart Association class decreased from 3 +/- 1 to 1.6 +/- 0.7 at the end of follow-up. Hemodynamic performances were satisfactory in both 19-mm and 21-mm Perimount valves, with low peak and mean transvalvular gradients and good effective orifice areas, orifice area indices, and performance indices. CONCLUSIONS Perimount aortic valve in the small aortic annulus has yielded excellent long-term results and hemodynamic performances. Perimount is a very satisfactory option in elderly patients. Implantation of a Perimount bioprosthesis avoids enlargement of the small aortic annulus, reducing mortality and morbidity associated with this procedure.

Neutrophil function and cardiopulmonary bypass in humans. The effects of glucose and non-glucose containing bypass pump priming fluids

Defective polymorphonuclear neutrophil function during cardiopulmonary bypass (CPB) has been implicated as a cause of postoperative infection following open-heart surgery. Neutrophil function is known to be impaired in poorly controlled diabetics with elevations of blood glucose concentrations of the order which occur frequently during CPB when glucose containing priming fluids are used. Neutrophil function, as measured by bactericidal assay, and neutrophil and whole blood luminol dependent chemiluminescence, was studied in two groups of 1 2 patients undergoing coronary artery bypass graft surgery. Patients received either a glucose or non-glucose containing bypass pump-priming fluid. Postoperatively neutrophil luminol-dependent chemiluminescence was significantly increased in both groups (glucose prime groups p < 0.01, non-glucose prime group p < 0.01). Whole blood chemiluminescence was increased significantly intra and postoperatively in the glucose prime group (p < 0.02, p < 0.02 respectively) but the increase was not significant in the non-glucose prime group. Bactericidal activity remained unchanged during and after surgery in both groups (mean bactericidal index intraoperatively 96.4 glucose group, 96.2 non-glucose group; postoperatively 99.7 glucose group, 99.7 non-glucose group). These data suggest that glucose containing bypass priming fluids do not modulate significantly the function of circulating neutrophils after CPB. Neutrophil function was not decreased after surgery, and other factors may be responsible for the reported higher incidence of bacterial infection after CPB.

The cardiopulmonary bypass pump-priming fluid and nitrogen balance after open-heart surgery in adults

Different crystalloid cardiopulmonary bypass pump-priming fluids provide very different substrate loads to patients undergoing open-heart surgery. As a result they may modulate the endocrine milieu, and thus might be expected to alter postoperative nitrogen balance. To test this hypothesis, 24 adult patients undergoing open-heart valve surgery were randomized into four matched groups each to receive a different prime, namely: Hartmanns solution, Plasmalyte 148R, Solution 11 R and a prime consisting of equal volumes of Hartmanns solution and 5% dextrose. Accurate nitrogen balance studies were obtained each 24 hours from one day preoperatively to seven days postoperatively. The results obtained demonstrated that postoperative nitrogen balance was unaffected by the nature of the crystalloid pump prime. Nitrogen balance in the patients studied was better than that reported from other centres in similar patients.

Safer Insertion of Ionescu-Shiley Valves in the Atrioventricular Position

Abstract The presence of rigid commissural struts in the strut of the Ionescu-Shiley pericardial xenograft valve makes insertion into the atrioventricular position difficult. A safe method of insertion using interrupted sutures is described.

The Cuffed Endotracheal Tube in Emergency Cardiopulmonary Bypass Operations

A new use of the cuffed endotracheal tube as a right atrial venous return cannula in emergency cardiopulmonary bypass operations is described. The ready availability, low cost, and design of the cuffed endotracheal tube make it ideal in this situation. We have used it successfully on three occasions.