Why is aortic valve-preserving surgery not popular?

One reason why surgeons have been reluctant to perform AVP may involve the conservative nature of the guidelines over the last decade. The current guidelines specify AVR as the standard surgical option in cases of AR. Therefore, they recommend aortic valve surgery in symptomatic patients or those with reduced left ventricular function as a class I indication13, 14. However, cases with depressed left ventricular function or advanced symptom are known to be associated with elevated mortality even after AVR15, 16. In addition, when AVP is planned, better quality of repair can be anticipated before degeneration of the aortic cusps.
Of course, some researchers recognized these concerns and proposed earlier indication for surgical intervention. The Mayo clinic reported that patients with indexed left ventricular endosystolic dimension (LVESD) ≥ 20 mm/m2 had poorer survival at 10 years compared to those with indexed LVESD < 20 mm/m2 (Fig. 4A)17. The Cleveland clinic also reported that patients with indexed LVESD between 20 and 25 mm/m2 had a survival benefit after AVR compared to those without AVR3. Patients with LVEF ≥ 50% but < 55% were reported to have poorer survival at 10 years compared to those with LVEF ≥ 55% (Fig. 4B)18. Even after AVR, patients treated in accordance with the guidelines for earlier surgery showed better survival than those undergoing later operation19. Therefore, the latest Japanese guidelines recommend aortic valve surgery in patients with LVESD > 45 mm as a class IIa indication, taking Japanese body size into account (English version will be available soon).
Another reason may be complexity of AVP. Compared with the mitral valve, the aortic valve has smaller cusp volume, thinner cusp thickness, and three coaptation planes20. There are many technical alternatives for MVP, whereas there is no chordal replacement technique in AVP. Thus, a long learning curve of approximately 40 – 60 cases is estimated for AVP, which has made this a technique exclusively for experienced surgeons21. Several technical/theoretical modifications or refinements have been made to increase adoption of AVP, which will be introduced in the following section.