When are PVA particles used in embolisation?
PVA particles range in size from 50 to 2000 µm. Their mechanism of action is to obstruct vessels physically and incite extensive granulation tissue formation. PVA particles result in permanent occlusion. The size of the particle used is based on the location of desired thrombosis. The smaller the particles are, the more distal the embolization. Particle selection is often based on the experience of the operator. If the particles selected are too small, end-organ ischemia and necrosis may occur. If the particles are too large, collateral vessels may quickly reconstitute blood flow to the target organ, significantly decreasing the efficacy of the procedure. The smallest particles are reserved for tumor embolization or preoperative devascularization of other tissues because they can cause significant tissue ischemia via occlusion down to the capillary level.
When performing an embolization procedure, why is it always recommended to place a vascular sheath at the access site?
A vascular sheath assists in catheter exchanges during the procedure. More importantly, the sheath maintains vascular access in the event the embolic agent clogs the delivery catheter, and the catheter needs to be removed.