Thoracic duct ligation and pericardectomy for idiopathic chylothorax in dogs: results in six dogs (May 2005 – July 2006)

Introduction: A retrospective investigation of the outcome and complications of thoracic duct (TD) ligation combined with pericardiectomy for dogs with idiopathic chylothorax was performed. Materials and methods: All dogs presented for surgical treatment of idiopathic chylothorax betweenMay 2005 and July 2006 were enrolled in the study. A diagnosis of chylothorax was made on the basis of the presence of pleural fluid containing cholesterol:triglyceride ratio of lower than 1. Oneml kg1 of corn oil was administered per os 2 hours before surgery to improve TD visualization. A right-sided 11th intercostal thoracotomy was performed and the TD was ligated with silk ligatures. A right-sided 4th intercostal thoracotomy was performed for partial pericardiectomy A chest drain was placed through the right 7th intercostal space and all pleural fluid was removed until drain removal 48 hours postoperatively Patients were discharged after 72hrs and fed on a low fat diet. Clinical re-assessment was performed 4 weeks after surgery and included an evaluation of respiratory function and pleural fluid accumulation by chest radiography. Patients were followed up by phone contact for a minimum period of six months unless presented before then for investigation of further respiratory signs. Results: Six dogs were enrolled in the study, 4 males and 2 females. Breeds included Cairn Terrier (2), Bichon Frise (1), German Shepherd (1), Greyhound (1) and Siberian Husky (1). Median weight and age were 141 (6–45) kg and 3 (2–6) years. Signs at admission included dyspnea (6), anorexia (3), lethargy (2), and weight loss (1). The presence of chyle was confirmed by thoracentesis and cholesterol:triglyceride ratio o1. Median volumes of 0.44 (0–16.67) ml kg1 48h1 of fluid were removed from the drains postoperatively Assessment at 4 weeks showed 5 dogs were clinically normal and had no radiographic signs of pleural fluid. 1 dog had radiographic signs of modest pleural fluid accumulation but was asymptomatic; re-assessment at 3 months showed similar radiographic and clinical findings. Conclusions: This study confirms that the success rate for the surgical management of chylothorax is markedly improved by combing pericardiectomy with TD ligation. This approach may be considered as ‘first line’ approach to the management of chylothorax in the dog.