Short-term hemodynamic advantages of stentless CryoLife-O'Brien valve over stented bioprostheses for aortic valve replacement

ARTICLE IN PRESS doi:10.1510/icvts.2006.133967 Interactive CardioVascular and Thoracic Surgery 5 (2006) 578–580 www.icvts.org Institutional report - Cardiac general Short-term hemodynamic advantages of stentless CryoLife-O’Brien valve over stented bioprostheses for aortic valve replacement Didier Chatel*, Cristina Mica, Didier Blanchard, Francis Baud, Didier Bruere, Arnaud Maudiere, Patrick Peycher Received 1 April 2006; received in revised form 3 June 2006; accepted 4 June 2006 Abstract For the CryoLife-O’Brien valve (CryoLife Inc, Kennesaw, GA, USA), implanted with a single suture line, we aimed to analyze the surgical requests and the hemodynamic results compared to stented bioprostheses. Two groups of patients requiring isolated aortic valve replacement from this population were compared retrospectively: 84 patients receiving the stentless CryoLife-O’Brien valve (Group A) and 94 patients receiving stented bioprostheses (Group B). Preoperative characteristics of patients were statistically equivalent for both groups. Statistically significant differences were observed only for operative durations and post-operative transprosthetic gradients: Aorta cross-clamp and cardio-pulmonary bypass durations were statistically longer for Group A than for Group B (45.9"5.7 min vs. 41.1"6.8 min; P-0.0001; and 64.3"11.6 min vs. 59.3"11.9 min, respectively; Ps0.0053); maximal gradients and mean gradients were 19.9"10.9 mmHg vs. 25.6"10.4 mmHg (Ps0.0008) and 10.8"5.3 mmHg vs. 14.8"6.4 mmHg (P-0.0001). Few surgical constraints and early post-operative hemodynamic efficiency of the stentless CryoLife-O’Brien valve means that this bioprosthesis can be intented in current practice for the aortic valve replacement in elderly patients. 䊚 2006 Published by European Association for Cardio-Thoracic Surgery. All rights reserved. Keywords: Aortic valve replacement; Stentless bioprostheses 1. Introduction Biological bioprostheses were conceived and developed to replace diseased cardiac valves in order to avoid anticoagulation. Their development evolved in cycles: initially heterologous grafts were used without prosthetic support, then such grafts were mounted on a stent with a suture ring to facilitate surgical implantation. Finally, bioprostheses were developed without stents or ring to improve hemodynamic performance, but the surgical implantation technique is more demanding for this kind of prosthesis. The CryoLife-O’Brien stentless valve was developed to provide the implantation of a stentless bioprosthesis, according to a specific surgical technique, aiming to achieve hemodynamic improvement with possible clinical advantages. In this study we compared the immediate outcomes of patients with isolated aortic valve stenosis treated by placement of either a CryoLife-O’Brien valve or a stented bioprosthesis. and 178 were included in this study. A CryoLife-O’Brien valve was implanted in 84 patients (Group A) and the other 94 received a stented bioprosthesis (Carpentier–Edwards Perimount (Baxter Healthcare Corp, Edwards Division, Santa Ana, CA, USA); Mitroflow (Sorin Group Inc, Mitroflow Division, Vancouver, Canada); Medtronic Mosaic (Medtronic Inc, Minneapolis, MN, USA). Surgery was performed with normothermic cardiopulmonary bypass (CPB). Cardioplegia was maintained with repeated anterograde injections of warm blood cardioplegia solution (GIK-type) every 12 min. CryoLife-O’Brien stentless bioprostheses implantation was supra-annular, with a single line of suture using a Prolene 3y0, according to the previously reported technique w1x. Stented bioprostheses were implanted with interrupted sutures. All patients were evaluated with early post-operative echocardiography when they were totally ambulatory, so free from any drug and pacing, and able to be discharged (generally before the 8th post-operative day). The statistical comparison was performed according to a one-way analysis of variance with significancy of 0.05. 2. Patients and methods From September 1999 to September 2004 bioprostheses were implanted in 285 patients with aortic valve stenosis; we only studied patients without coronary artery disease *Corresponding author: Tel.: q33 2 47 66 30 13; fax: q 33 2 47 64 35 66. E-mail address: (D. Chatel). 䊚 2006 Published by European Association for Cardio-Thoracic Surgery 3. Results Pre-operative characteristics (age, morphometric data and pre-operative risk factors evaluated by EuroSCORE) (Table 1) were strictly equivalent for both groups, thus avoiding bias in the post-operative analysis of data. Departments of Cardiovascular Surgery and Cardiovascular Medicine, Clinique Saint Gatien, 8, place de la Cathédrale 37000 Tours, France ARTICLE IN PRESS D. Chatel et al. / Interactive CardioVascular and Thoracic Surgery 5 (2006) 578–580 579 Table 1 Pre-operative characteristics of patients and models of implanted bioprostheses Group B (ns94) P-value 76.9"4.8 48y36 1.82"0.21 6.73"1.25 23 (27.3%) 85"21.2 56.8"13.6 0.57"0.11 84 (100%) 0 (0%) 0 (0%) 0 (0%) 77.8"3.5 56y38 1.85"0.19 7.11"1.42 27 (28.7%) 79.6"24.8 55.6"15.8 0.59"0.10 0 (0%) 33 (35.2%) 24 (25.5%) 37 (39.3%) 0.187 0.742 0.242 0.062 0.9 0.122 0.588 0.303 BSA, Body Surface Area; LVEF, Left Ventricular Ejection Fraction. Aorta cross-clamp and CPB durations were statistically longer for Group A than for Group B (45.9"5.7 min (min. 32 min, max. 60 min) vs. 41.1"6.8 min (min. 25, max. 70 min); P-0.0001; and 64.3"11.6 min vs. 59.3"11.9 min, respectively; Ps0.0053). The mean size of stentless bioprostheses was statistically larger than that of stented bioprostheses (25.02 mm" 2.3 mm vs. 23.2 mm"1.7 mm, respectively; P-0.0001). Distribution of bioprostheses according to size is summarized in Fig. 1. Five patients from Group A and 6 patients from Group B died during the early post-operative period. Death during hospitalization was not statistically different between the two groups (5.9% Group A vs. 6.3% Group B; Ps0.9). Causes of death in Group A comprised cardiac failure (2 patients), multiorgan failure (1 patient), respiratory failure (1 patient) and ventricular fibrillation (1 patient). In Group B they comprised cardiac failure (4 patients), multiorgan failure (1 patient) and hemorrhage (1 patient). Early echographic evaluation of the bioprostheses showed significantly lower transprosthesis gradients in the stentless bioprostheses than in the stented bioprostheses, the maximal gradients being 19.9"10.9 mmHg and 25.6"10.4 mmHg for Groups A and B, respectively (Ps0.0008), and mean gradients being 10.8"5.3 and 14.8"6.4 mmHg for Groups A and B, respectively (P-0.0001). Fig. 1. Distribution of bioprostheses according to size. 4. Discussion The value of stentless bioprostheses reported by surgeons is variable and contradictory. Although the hemodynamic profile of such prostheses has encouraged their use, most surgeons consider that the surgical techniques are more demanding (usually 2 lines of sutures), thus engendering reluctance (...truncated)