Degenerative mitral valve regurgitation is a progressive disease involving the leakage of blood into the left atrium from the left ventricle during systole. Although surgical interventions have advanced greatly, morbidity remains high and proven pharmacological solutions are lacking. The classic recapitulation model involves an invasive thoracotomy procedure, thereby limiting translational results. The current study investigates the efficacy of a new, minimally invasive transthoracic ultrasound-guided closed-chest surgery model using the Prospect T1 (Now Prospect T2) high-frequency ultrasound system.
A Novel Procedure for Reproducing Mitral Valve Regurgitation
The authors used ultrasound guidance to introduce a 27-gauge needle to the anterior mitral valve leaflet. The valve was perforated using real-time imaging and sham controls underwent an identical procedure without leaflet perforation. This method of mitral valve regurgitation avoids thoracotomies and, subsequently, advanced post-operative care.
Mitral Valve Perforation Recapitulates the Functional Effects of Mitral Valve Regurgitation
Similar to mitral valve regurgitation patients, mouse mitral valve perforation led to a significant decrease in systolic and diastolic blood pressures after 14- and 28 days, lowered fractional shortening, and increased left atrial diameters and left ventricular internal dimensions at end-diastole.
Figure 1. Establishment of a minimally invasive mouse model of mitral regurgitation. (A) Schematic illustration of transthoracic, echocardiography-guided puncture of the anterior mitral leaflet via a 27G needle introduced through the LV apex. (B,C) Representative echo-guided needle visualization in the (B) LV and (C) MV. Changes in (D) systolic, (E) diastolic, and (F) mean blood pressure in sham and MR mice at baseline, 14-day, and 28-day time points. Quantification of (G) LA diameter, (H) VC width, (I) IVSD, (J) LVIDd, and (K) FS. (L) Survival curves demonstrating >90% procedural survival. (M) Representative echocardiographic images showing color Doppler-confirmed regurgitant jet in MR vs sham. Sham (N=8), MR mice (N=10). Data are expressed using mean±SE. P value determined using Student’s t test. AO indicates aorta; BW, body weight; DBP, diastolic blood pressure; FS, fractional shortening; HR, heart rate; IVSD, interventricular septum in diastole; LA, left atrium; LV, left ventricle; LVIDd, left ventricular internal dimension at end-diastole; MR, mitral regurgitation; MV, mitral valve; SBP, systolic blood pressure; and VC, vena contracta. *P<0.05.
System Used
Mitral valve perforation and subsequent cardiac function was tracked non-invasively by high-frequency echocardiography using the Prospect T1 (Now Prospect T2). Click the link below to learn more about how the Prospect T2 can drive your studies forward.
Prospect T2
Preclinical Ultrasound System
The Prospect T2 is an innovative high-frequency ultrasound system designed specifically for in vivo preclinical imaging in small animals such as mice and rats. This compact and cost-effective tablet-based system provides high-resolution images (up to 30 µm) and advanced capabilities to monitor changes in hemodynamics and observe anatomical structures in real-time.
View key capabilities
- Compact & Small Footprint
- Add-on Hardware/Software Options
- Multiple Probes & Platforms
- Simplified Image Guided Injection Mount
References
https://pmc.ncbi.nlm.nih.gov/articles/PMC3560836/ (for MR valve regurg. in the clinic).
