Sclerosing and Embolizing Gel for Venous Embolization: Feasibility Study in a Porcine Model

Purpose: To evaluate the safety and effectiveness of venous embolization using a temporarily radiopaque embolizing gel composed of chitosan (CH) and sodium tetradecyl sulfate (STS) in a porcine model. Materials and Methods: In 15 domestic pigs, the retromandibular veins (RMVs) and/or deep femoral veins (DFVs) were embolized. Gel was injected following proximal coiling in 15 of 26 veins and without coil protection in 11 of 26 veins. Primary outcomes were venous occlusion and gel/coil migration events at Day 30 (D30). Histopathological analysis of embolized veins was performed. Results: Gel embolization was technically successful in all veins. Complete venous occlusion at D30 was observed in 11 (92%) of 12 RMVs and 11 (79%) of 14 DFVs. Gel radiopacity was good to excellent at Day 0 (D0), whereas no residual radiopacity was observed at D30. Injectability was excellent with no catheter adhesion events. At D0, 1 pig had minimal gel migration to the lungs. At D30, coil migration was observed in 6 (50%) of 12 animals and 9 (60%) of 15 veins. Gel migration to the lungs was observed in 14 (93%) of 15 animals. All events of gel migration were associated with either occurrence of coil migration or absence of coil protection. The only animal with successful coil protection of all veins had no evidence of gel migration to the lung. On histology, veins with stable coil protection had higher gel content than veins without coil protection or coil migration. Conclusions: Venous embolization using CH-STS gel is technically successful and produces excellent venous thrombosis. In this model, stable coil protection is necessary to prevent gel migration.