Abstract:

 

Aims: Pressure recovery (PR) is essential part of the post stenotic fluid mechanics

and depends on the ratio of EOA/A A , the effective aortic valve orifice area (EOA) and

aortic cross-sectional area (A A ). In patients with advanced ascending aortic aneurysm

and mildly diseased aortic valves, the effect of A A on pressure recovery and

corresponding functional aortic valve opening area (ELCO) was evaluated before and

after valve-sparing surgery (Dacron graft implantation).

Methods and results: 83 Patients with ascending aortic aneurysm (mean aortic

diameter 57+/-10mm) and aortic valve-sparing surgery (40 reimplantation technique

(David), 43 remodeling technique (Yacoub)) were routinely investigated by Doppler

echocardiography. Dacron prostheses with a diameter between 26 and 34mm were

implanted. EOA was significantly declined after surgery (3.5+/-0.8 vs.2.7+/-0.9cm 2 ;

p<0.001). Insertion of Dacron prosthesis resulted in a significant reduction of A A

(26.5+/-9.6 vs. 6.8+/-1.2cm 2 ; p<0.001) with increased ratio of EOA/A A (0.15+/-0.06 vs.

0.40+/-0.1; p<0.001) and pressure recovery index (PRI; 0.25+/-0.08 vs. 0.44+/-0.06;

p<0.0001). Despite reduction of EOA, ELCO (= EOA corrected for PR) increased

from 4.2+/-1.1 to 5.2+/-3.6cm 2 (p<0.01) with reduction in LV stroke work (966+/-743

to 390+/-523 mmHg x ml, p<0.0001) after surgery. These effects were significantly

better in patients with Yacoub technique at rest and during physical stress than with

the David operation.

Conclusion: The hemodynamic findings demonstrate a valve-vessel interaction

triggered by a marked reduction in the ascending aortic cross-sectional area with

significant PR gain. The greater hemodynamic benefit of the Yacoub technique due

to higher EOA values compared to David technique could be of clinical relevance.