Prolonged survival with mitral valve plasty for acute mitral regurgitation due to mitral valve dysplasia and chordal rupture in a young small dog: A case report

Fig. 1.. Preoperative thoracic radiography (lateral view). (a) Thoracic radiograph recorded at the initial examination (5 months old) shows moderate heart enlargement (VHS, 10.7 v) and lung edema in the posterior pulmonary lobes. (b) Thoracic radiograph recorded after 4 months (just before surgery, 9 months old) shows heart enlargement (VHS, 11.2 v) with tracheal and left bronchial elevation and lung congestion. VHS: vertebral heart scale.

Fig. 2.. Color Doppler echocardiography. (a) Color Doppler echocardiograph from the initial examination shows a mosaic flow (mitral regurgitation: large white arrow) during systole due to chordal rupture (small arrows) (two-chamber view). (b) Color Doppler echocardiograph recorded directly before surgery shows a mosaic flow (large white arrow) during systole retrograded along the posterior wall of the enlarged LA (four-chamber view). AO: aorta; LA: left atrium; LV: left ventricle.

Fig. 3.. Surgical view and pre- and postoperative schematics of MVP. (a) In the surgical view, the anterior valve leaflet (AL) is ridden up due to chordal rupture, shown by the right-angle clamp (RAC) and a pincette (P). To open up the surgical field, the posterior valve leaflet (PL) is pulled backward with a cross uncus (CU). (b) Pre-MVP schematic shows mitral valve dysplasia in the whole extent of the anterior commissure (AC) (in red circle), a bulge at A1-2 due to elongated chorda (green arrow), evidence of a chorda at A2 (orange arrow), and two chordal ruptures at A2-3 and A3 (red arrows). (c) The post-MVP schematic shows MVP with the artificial chordal reconstruction using three PTFE sutures between A1-2 of the AL and the anterior papillary muscle, between A2-3 of the AL and the posterior papillary muscle (PPM), and between A3 of the AL and PPM. In addition, annuloplasty was performed using the mattress technique (Kay method) with two pledgeted 5-0 Proline sutures in the posterior commissure. (A1): anterior commissure side of AL; (A2): middle portion of AL; (A3): posterior commissure side of AL; (ARc): aortic route cannula; LA: left atrium; LV: left ventricle; (SC): suction tube.

Fig. 4.. Postoperative thoracic radiography (lateral). (a) Thoracic radiograph recorded 3 months postoperatively shows heart size reduction (VHS: from 11.8 v preoperatively to 10.5 v postoperatively). (b) At 7 years postoperatively, a thoracic radiograph shows heart size almost the same size (VHS: 10.9 v) as that at 3 months postoperatively. VHS: vertebral heart scale.