Thoracoscopic resection of cranial mediastinal masses: Retrospective study in 17 cats

Objective To evaluate the feasibility, complications and outcomes of thoracoscopic resection of cranial mediastinal masses in cats. Study design Multi‐institutional retrospective study. Animals A total of 17 client‐owned cats. Methods Data collected from medical records of cats that underwent thoracoscopic surgery for cranial mediastinal masses between January 2019 and December 2024 included signalment, history, clinicopathologic features, preoperative diagnostic imaging and tumor measurement, anesthesiologic and surgical procedures, complications, and short‐ or long‐term follow‐ups. Results The most common clinical sign was dyspnea. All cats started with thoracoscopic surgical exploration. Non‐emergent conversion to an open procedure (sternotomy or video‐assisted procedures [VATS]) was necessary in six of 17 (35.29%) cats, with conversions primarily occurring in cases with masses larger than 5 cm. The median maximal tumor diameter was 6 cm (range: 2.2–8.1 cm). The most common tumor type was thymoma, identified in 12 of 17 (70.59%) cats. All cats survived the perioperative period and were alive at the short‐term follow‐up. Mean survival time was 390.62 days. Conclusion The presence of larger tumor sizes and adhesions were associated with higher conversion rates to open or VATS procedures, underscoring the importance of tumor dimensions in surgical planning. Clinical significance Thoracoscopic surgery for cranial mediastinal masses in cats is technically feasible, with favorable short‐24 and long‐term outcomes. Conversion rates were lower in cats with smaller masses without adhesions in this study.