Palliative Debulking of an Aortic Body Tumour With Right Atrial Invasion in a Dog Under Partial Cardiopulmonary Bypass
Shuji Suzuki, Sachiyo Tanaka, Nobuo Kanno, Takuya Yogo, Yasuji Harada, Masaki Michishita, Yasushi HaraABSTRACT
Background
Aortic body tumours are uncommon heart‐base neoplasms in dogs, and intracardiac extension causing clinically significant right atrial obstruction is rarely described.
Case presentation
A 7‐year‐1‐month‐old, 15.2‐kg, castrated male French Bulldog was evaluated for 2 weeks of lethargy, hyporexia, exercise intolerance, abdominal distension, and polydipsia. Transthoracic echocardiography revealed severe right‐sided cardiac enlargement and a heterogeneous right atrial intracavitary mass (3.2 × 3.1 cm) suspected to arise from the heart base, with tricuspid regurgitation (maximal velocity 4.03 m/s). Abdominal ultrasonography showed hepatic venous congestion and marked ascites; fluid was a modified transudate. Medical therapy failed to resolve ascites, and surgical debulking was performed on Day 7 under partial cardiopulmonary bypass. The mass was firmly adherent to the atrial septal aspect and could not be completely excised. Postoperatively, ascites and clinical signs resolved, right‐sided cardiac enlargement decreased, and tricuspid regurgitation was no longer detectable; the dog was discharged on Day 14. A recurrent right atrial mass was documented on Day 360 without recurrence of right‐sided heart failure. The dog died on Day 390 from pancreatitis‐associated biliary obstruction and multiple organ failure. Necropsy confirmed an aortic body tumour with intracardiac extension into the right atrium and pulmonary metastasis with tumour emboli.
Conclusion
Partial cardiopulmonary bypass‐assisted palliative debulking may temporarily relieve life‐limiting intracardiac obstruction in carefully selected dogs; however, this approach is high‐risk and non‐curative, and its contribution to long‐term survival remains uncertain because postoperative toceranib therapy and the natural behaviour of the tumour may also have influenced the clinical course.