Biomed Res Int. 2015;2015:753210. doi: 10.1155/2015/753210.
Novel Model of Pulmonary Artery Banding Leading to Right Heart Failure in Rats.
- 1Departments of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
BACKGROUND: Congenital heart diseases often involve chronic pressure overload of the right ventricle (RV) which is a major cause of RV dysfunction. Pulmonary artery (PA) banding has been used to produce animal models of RV dysfunction. We have devised a new and easier method of constricting the PA and compared it directly with the partial ligation method.
METHODS: Eight-week-old male Sprague-Dawley rats (240-260 g) were divided into three groups: sham operation, partial pulmonary artery ligation (PAL) procedure, and pulmonary artery half-closed clip (PAC) procedure. RV function and remodeling were determined by echocardiography and histomorphometry.
RESULTS: Surgical mortality was significantly lower in the PAC group while echocardiography revealed significantly more signs of RV dysfunction. At the 8th week after surgery RV fibrosis rate was significantly higher in the PAC group.
CONCLUSIONS: This procedure of pulmonary artery banding in rats is easier and more efficient than partial ligation.
Right heart failure is important in congenital heart disease and pulmonary hypertension, because patients with these diseases often survive to adulthood, while many of the non-survivors die of right heart failure. This new procedure might make various right heart failure models in rats feasible and facilitate research on its pathophysiology and treatment.
This procedure is very precise and efficient, and might prove adaptable by many investigators. In this procedure, the clip might be removed at selected stages and rats in different stages of right heart failure produced, moreover, we should be able to study the border line between reversible and irreversible changes in the stressed right ventricle, These experiments have not been performed in the existing procedure.
Fig.1 : The PAC procedure through the left thoracotomy
A: The main PA was exposed through the left thoracotomy.
B: placed a half closed clip around the main PA.
C: pulmonary artery with a placed clip without migration at the sacrifice time.
D: the cross section of the main PA.
Scale bar : 1mm
Fig.2: Echocardiographic images of sham and RV failure rats (FAIL) induced by the PAC procedure.
A: 2D parasternal short axis view. IVS shifted to the left in FAIL case.
B: 4 chamber view IVS shifted to the left and RA dilated owing to tricuspid regurgitation.(D)
C: pulmonary artery flow was obtained by pulsed Doppler . PA flow was almost 1m/s in the sham case, but was almost 4m/s in FAIL case.
D: severe tricuspid regurgitation (TR) detected by color Doppler
E: inferior vena cava (IVC) dilation induced by TR. Pleural effusion was also detected.
RV; RV cavity, LV; LV cavity, IVS; interventricular septum, RA; right atrium, LA; left atrium
Masataka Hirata, M.D.
Departments of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hospital, Okayama, Japan
Kita-ku, Okayama 700-8558, Japan