Prevention of prosthesis-patient mismatch during aortic valve replacement

Abstract

Objective The prosthesis used for aortic valve replacement (AVR) can be too small in relation to body size,thus causing valve prosthesis-patient mismatch (PPM).The aim of this article was to summarize the preventive strategy of PPM during AVR.Methods A total of 357 patients [203 males,154 females; mean age (54.9 ± 18.7 ) years ] underwent AVR between February.2010 and December 2011.The weight and body surface area (BSA) of the group is( 60.1 ± 11.4 )kg and (1.67 ± 0.21 )m2 respectively.The aortic valve prosthesis effective orifice area (EOA) was divided by body surface area (BSA) to obtain the EOA index (EOAI).PPM was then defined as none or mild if EOAI was ＞ 0.85 cm2/m2,as moderate for (0.65 - 0.85 ) cm2/m2 and as severe for ＜ 0.65 cm2/m2.To avoid PPM,a simple three-step algorithm was applied:Step 1,Calculate the patient's BSA from weight and height;Step 2,Calculate the minimal valve EOA required based on the BSA to ensure an EOAI ＞0.85 cm2/m2 ; Step 3,Select the type and size of prosthesis that has reference values for EOA greater or equal to the minimal EOA value obtained in step 2.For patients with a small aortic root,the following three methods was used:( 1 ) Replace aortic valve with simple interrupted suture technique ; (2) Apply new type and high-performance prosthetic valves such as St.Jude Medical Regent mechanical valve ; (3) Enlarge the narrowed aortic root when necessary.Results Of all 357 patients,272 patients received mechanical AVR and 85 bioprosthetic AVR.Among the 49 patients who received AVR with simple interrupted suture technique.St.Jude Medical Regent mechanical valve was implanted in 38 patients and the aortic root enlargement was performed in 11 patients.The total prevalence of PPM was 6.4％ and there was no severe PPM.The prevalence of PPM with mechanical AVR and bioprosthetic AVR was 1.8％ and 21.2％ respectively.There were 4 deaths during early period of operation,and the operative mortality was 1.1％.Conclusion Prosthesis-patient mismatch can be effectively prevented at the time of AVR with appropriate measurement. Key words: Heart valve prosthesis; Heart valve prosthesis,implantatior; Prosthesis-patient mismatch