Simultaneous surgical repair of a cardiac myxoma causing left ventricular outflow tract obstruction and a ventricular septal defect in a small dog

Figures

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  Fig. 1.. Echocardiography of the right parasternal long-axis view. (a) B-mode echocardiography shows a small polypoid mass (arrow) at the top of the interventricular septum below the aortic valve. (b) Color Doppler echocardiography of the same view shows two mosaic flows during systole due to a membranous ventricular septal defect (VSD, 3.17 mm in diameter) at the top of the ventricular septum and obstruction of the left ventricular outflow tract (LVOT), respectively. LV: left ventricle, AO: aorta, LA: left atrium, RV: right ventricle.

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  Fig. 2.. CWD echocardiography of the right parasternal long-axis view. (a) The blood flow velocity in the left ventricular outflow tract (LVOT) was 4.55 m/seconds, with a calculated systolic pressure gradient (ΔP) of 83 mmHg between the LV and aorta (AO). The AR blood velocity was 3.11 m/seconds, with a calculated diastolic ΔP of 39 mmHg between the LV and AO. (b) The blood flow velocity in the ventricular septal defect (VSD) was 4.55 m/seconds, with a calculated systolic ΔP of 83 mmHg between the LV and RV. The peak velocity measurement of LVOT, AR, and VSD is not accurate, because of measurements taken using the “beard” instead of the “chin” (see “Study Limitations”).

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  Fig. 3.. Surgical procedures and views. (a) After right atriotomy, a balloon-tipped urethral catheter (UC) was inserted into the CSO for retrograde cardioplegia. A membranous VSD foramen (three black-headed arrows) was found under the cranial part of the septal leaflet of the tricuspid valve. Two white arrows show two ligated 5–0 Prolene sutures using the mattress suture technique for direct closure of VSD. (b) After oblique aortotomy (arrows), a pinkish fibrous tumour (T) (10 × 8 × 4 mm) was observed immediately below the RCC. RV: right ventricle, ACC: aortic cross clamp, CVCc: caudal vena cava cannula, ARc: aortic root cannula, RAA: right atrial appendage.

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  Fig. 4.. CWD echocardiography after surgery. (a) Five days after surgery, the systolic pressure gradient (ΔP) between the LV and aorta (AO) had decreased from 83 mmHg (the preoperative value) to 40 mm Hg. The corresponding values for left ventricular outflow tract (LVOT) velocity were 4.55 and 3.17 m/seconds, respectively. (b) Thereafter, the values were essentially unchanged and were 48.7 mmHg (ΔP) and 3.49 m/seconds (LVOT) at 8.5 months.

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  Fig. 5.. Histopathology of the cardiac myxoma. Spindle-shaped fibroblast-like cells are sparsely distributed throughout a faintly eosinophilic myxoid matrix. Haematoxylin and eosin, 200× magnification.