Glutaraldehyde cross-linked collagen (GAX): a new material for therapeutic embolization

In a search for a better agent for use in therapeutic embolization, a newly available bovine collagen product, glutaraldehyde cross-linked collagen (GAX), was evaluated to determine its effectiveness in causing arterial obstruction, its persistence after embolization, and the acute and chronic pulmonary toxicity resulting from direct pulmonary embolization. GAX is an effective agent for causing arterial obstruction: 3-4 ml caused prompt flow arrest when injected into the internal iliac artery of six dogs. In this canine model, the material persisted within embolized tissue for as long as 2 months, and at follow-up intervals of 2 days, 2 weeks, and 2 months, its presence did not produce any cellular response. Studies of both acute and chronic pulmonary toxicity reveal that when GAX is embolized directly into the pulmonary circulation it causes adverse effects only by mechanical blockage of pulmonary arteries. GAX offers several advantages over other currently available agents and is of sufficient safety that clinical trials in humans can be undertaken.