TY - JOUR
T1 - Effects of Annular Size, Transmitral Pressure, and Mitral Flow Rate on the Edge-To-Edge Repair
T2 - An In Vitro Study
AU - Jimenez, Jorge H.
AU - Forbess, Joseph
AU - Croft, Laura R.
AU - Small, Lisa
AU - He, Zhaoming
AU - Yoganathan, Ajit P.
N1 - Funding Information:
This work was supported by a grant from the National Heart, Lung, and Blood Institute (HL52009).
PY - 2006/10
Y1 - 2006/10
N2 - Background: Although edge-to-edge repair is an established adjunctive procedure, there is still debate on its long-term durability and efficacy. Methods: Fifteen porcine mitral valves were studied in a physiologic left heart simulator with a variable size annulus (dilated = 8.22 cm2, normal = 6.86 cm2, contracted = 5.5 cm2). Mitral valves were tested under steady and physiologic pulsatile flow conditions (cardiac outputs: 4 to 6 L/min), at peak transmitral pressures between 100 mm Hg and 140 mm Hg. A miniature force transducer was used to measure the Alfieri stitch force (FA). Mitral flow rate (MFR), transmitral pressure, effective orifice area, mitral regurgitation, and FA were monitored. Results: The edge-to-edge repair led to a decrease in effective orifice area of 16.55% ± 8.22%; further reduction in effective orifice area was attained with annular contraction. Mitral regurgitation after the edge-to-edge repair was significantly higher (p <0.05) with annular dilation. In the pulsatile experiments, two peaks in FA were observed: one during systole (FA = 0.059 ± 0.024 N) and a second during diastole (FA = 0.072 ± 0.021 N). Multivariate analysis of variance analysis showed that during systole, transmitral pressure and mitral annular area (MAA) had significant effects on FA [FA = (4.40 × 10-4) transmitral pressure (mm Hg) + (5.0 × 10-3) MAA (cm2) - 0.05 (R2= 0.80)], whereas during diastole MFR and MAA had significant effects on FA [FA = (1.03 × 10-4) MFR2 (L/min) - (1.60 × 10-3) MAA (cm2) + 0.02 (R2 = 0.90)]. Conclusions: With annular dilation, mitral regurgitation persisted even after the edge-to-edge repair. The edge-to-edge repair does not cause clinically relevant mitral valve stenosis in a normal size mitral valve. Mitral flow rate and transmitral pressure are the main determinants of FA during the cardiac cycle. Increasing annular area increases FA during systole but decreases FA during diastole. Systolic FA may become dominant with increases in MAA or peak transmitral pressure, or both.
AB - Background: Although edge-to-edge repair is an established adjunctive procedure, there is still debate on its long-term durability and efficacy. Methods: Fifteen porcine mitral valves were studied in a physiologic left heart simulator with a variable size annulus (dilated = 8.22 cm2, normal = 6.86 cm2, contracted = 5.5 cm2). Mitral valves were tested under steady and physiologic pulsatile flow conditions (cardiac outputs: 4 to 6 L/min), at peak transmitral pressures between 100 mm Hg and 140 mm Hg. A miniature force transducer was used to measure the Alfieri stitch force (FA). Mitral flow rate (MFR), transmitral pressure, effective orifice area, mitral regurgitation, and FA were monitored. Results: The edge-to-edge repair led to a decrease in effective orifice area of 16.55% ± 8.22%; further reduction in effective orifice area was attained with annular contraction. Mitral regurgitation after the edge-to-edge repair was significantly higher (p <0.05) with annular dilation. In the pulsatile experiments, two peaks in FA were observed: one during systole (FA = 0.059 ± 0.024 N) and a second during diastole (FA = 0.072 ± 0.021 N). Multivariate analysis of variance analysis showed that during systole, transmitral pressure and mitral annular area (MAA) had significant effects on FA [FA = (4.40 × 10-4) transmitral pressure (mm Hg) + (5.0 × 10-3) MAA (cm2) - 0.05 (R2= 0.80)], whereas during diastole MFR and MAA had significant effects on FA [FA = (1.03 × 10-4) MFR2 (L/min) - (1.60 × 10-3) MAA (cm2) + 0.02 (R2 = 0.90)]. Conclusions: With annular dilation, mitral regurgitation persisted even after the edge-to-edge repair. The edge-to-edge repair does not cause clinically relevant mitral valve stenosis in a normal size mitral valve. Mitral flow rate and transmitral pressure are the main determinants of FA during the cardiac cycle. Increasing annular area increases FA during systole but decreases FA during diastole. Systolic FA may become dominant with increases in MAA or peak transmitral pressure, or both.
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U2 - 10.1016/j.athoracsur.2006.05.008
DO - 10.1016/j.athoracsur.2006.05.008
M3 - Article
C2 - 16996934
AN - SCOPUS:33748746934
SN - 0003-4975
VL - 82
SP - 1362
EP - 1368
JO - Annals of Thoracic Surgery
JF - Annals of Thoracic Surgery
IS - 4
ER -