Methods of Gradual Vascular Occlusion and Their Applications in Treatment of Congenital Portosystemic Shunts in Dogs: A Review

OBJECTIVE: To provide a comprehensive review of the experimental and clinical data related to gradual vascular occlusion of congenital portosystemic shunts (CPS) in dogs. STUDY DESIGN: Literature review. METHODS: PubMed literature search (1966-2004). RESULTS: Surgical intervention and complete vascular occlusion have been recommended for CPS therapy in dogs; however, acute complete ligation of CPS is often associated with life-threatening portal hypertension. Recently, several investigators have attempted to reduce the risk of postoperative portal hypertension by using gradual vascular occlusion. Successful vascular occlusion has been achieved using partial ligation with silk suture, ameroid constrictors, cellophane bands, thrombogenic coils and hydraulic vascular occluders. Objective comparisons of the reliability and rate of vascular occlusion produced by each of these methods have been limited by differences in experimental models and a lack of definitive follow up evaluation in some clinical studies. CONCLUSIONS: Gradual vascular occlusion is widely used in the clinical treatment of CPS in dogs. Objective evaluation of the experimental and clinical data on each of the techniques for gradual vascular occlusion is necessary for informed clinical practice and for the planning of future research into this important area. CLINICAL RELEVANCE: Even from the limited data available, it is clear that the ideal method for gradual vascular occlusion of CPS has yet to be identified.