An injectable tissue-engineered embolus prevents luminal recanalization after vascular sclerotherapy.

Background/purpose: Sclerotherapy for vascular malformations is often limited by luminal recanalization. This study examined whether an injectable tissue-engineered construct could prevent this complication in a rabbit model of venous sclerotherapy.
Methods: Ethanol sclerotherapy of a temporarily occluded jugular vein segment was performed in 46 rabbits, which were then divided into 3 groups. Group I (n = 16) had no further manipulations. In groups II (n = 15) and III (n = 15), 0.5 mL collagen hydrogel was injected intraluminally, respectively, devoid of and seeded with autologous fibroblasts. At 1, 4, and 20 to 24 weeks postoperatively, vein segments were examined for patency and resected for histological evaluation. Statistical analysis was by Fisher's Exact test.
Results: All vein segments were occluded at 1 and 4 weeks in all groups, despite histological evidence of progressive endothelial ingrowth. However, at 20 to 24 weeks, angiography demonstrated restoration of vessel patency in groups I (3/6) and II (3/5), but not in group III (0/6; P = .043), in which histology confirmed an obliterated lumen for all vessels.
Conclusion: An injectable, fibroblast-based, engineered construct prevents midterm to long-term recanalization in a leporine model of vascular sclerotherapy. This novel therapeutic approach may prevent recurrence of vascular malformations after sclerotherapy, thus reducing the need for repeated procedures and morbid operative resections.