Surgical Correction of Infundibular Muscular Ventricular Septal Defect in a Cat: A Case Report.

Ventricular septal defects (VSDs) can lead to congestive heart failure and pulmonary hypertension, particularly in patients with large shunts. However, no surgical treatment for feline VSD has been reported. Here, we elucidated the first surgical correction of an infundibular muscular VSD in a one-year-old Ragdoll cat, atypically located and classified under the Soto classification rather than the standard Kirklin classification, through cardiac arrest using cardiopulmonary bypass-a method rarely used in feline cardiac surgery. Detailed echocardiography revealed that the defect required intervention owing to left heart and main pulmonary artery enlargement. Despite the VSD being located on the contralateral side, as anticipated in the preoperative examinations, the choice of median sternotomy allowed for the successful closure of the defect. Conversely, the insertion of two cannulas into the ascending aorta resulted in damage to the adjacent thoracic duct, causing transient chylothorax, which was resolved with conservative treatment. Cardiac arrest induced by a cardioplegic solution facilitated the surgical procedure, although it leads to anemia in cats. However, on postoperative day 490, the patient exhibited only minor residual shunting, with normalized heart size, and remained healthy. This technique appears to be a viable treatment option for congenital heart disease in cats.

Combination of the Modified Loop Technique and De Vega Annuloplasty in Dogs with Mitral Regurgitation.

Background: Detailed surgical techniques for treating canine mitral regurgitation have not been previously reported. Method: This case series included six consecutive client-owned dogs with mitral regurgitation. All dogs underwent a combined protocol, including the modified loop technique and De Vega annuloplasty (MODEL surgery), in 2021. Artificial loops covering 80% of the length of the strut chordae tendineae were used for chordal replacement. Mitral annuloplasty was subjectively performed, targeting the circumference of the septal leaflet. Results: The breeds were Chihuahua-mixed breed, Spitz, Pomeranian, Cavalier King Charles Spaniel, and Chihuahua, with average ages and weights of 11.4 ± 2.3 years and 5.49 ± 2.98 kg, respectively. The aortic cross-clamp, pumping, and surgery times were 64.0 ± 7.5 min, 168.5 ± 39.1 min, and 321.0 ± 53.1 min, respectively. After MODEL surgery, left atrial-to-aortic ratios significantly decreased from 2.20 ± 0.18 to 1.26 ± 0.22 (p < 0.01), and left ventricular end-diastolic internal diameter normalized to body weight significantly decreased from 2.03 ± 0.26 to 1.48 ± 0.20 (p < 0.01). In all cases, the clinical signs disappeared or improved significantly. Conclusions: MODEL surgery increased mitral valve coaptation, normalized heart sizes, and significantly improved clinical signs in dogs with mitral regurgitation.