Treatment of idiopathic chylothorax in dogs and cats: A systematic review

Abstract Objective To evaluate the evidence published on the treatment of idiopathic chylothorax (IC) in small animals. Study design Systematic literature review. Sample population Dogs and cats with IC. Methods A literature search was performed in three bibliographic databases in July 2018 for publications on IC in dogs and cats. Articles meeting criteria for inclusion were evaluated for treatment, survival, outcome data, and level of evidence (LoE) with a modified Oxford Level of Evidence (mOLE) and GRADE (Grading of Recommendations, Assessment, Development and Evaluations) system. Results Eleven of 313 identified articles met the inclusion criteria. Only one study was identified in dogs as having higher LoE by using the mOLE system, whereas no study was identified as such in either species with the GRADE system. Surgery was the primary treatment in all dogs and in 93% (68/73) of cats. Medical therapy was the primary treatment in 7% (5/73) of cats. The most common surgical treatment combined thoracic duct ligation (TDL) and subtotal pericardiectomy (SP; 40%; 34/84) in dogs and TDL in cats (51% [37/73]). Conclusion The body of literature for IC treatment in small animals was limited to one higher LoE study in dogs and none in cats. No strong conclusion could be drawn regarding the effectiveness of any one surgical method in dogs or cats, and no evidence was found to support medical therapy as a primary treatment. Clinical significance The best available evidence regarding the treatment of IC is published in dogs and provides some support for surgical treatment with either TDL + cisterna chyli ablation or TDL + SP. Additional evidence is required to confirm this finding.