The Null technique as a novel, potential first-line method of device delivery for complicated lesions during percutaneous coronary intervention

AIM: During percutaneous coronary intervention (PCI), complicated lesions in the target coronary artery often hinder device delivery. Fluid lubricants have commonly been used to reduce friction between adjacent solid materials in manufacturing, thus achieving smoother action. This ex vivo experimental study examined whether a contrast medium could function as a fluid lubricant during PCI. METHODS AND RESULTS: We used two different coronary artery lesion models with distinct complexities made from silicon. Each model was fit into the ex vivo PCI-simulation system. This ex vivo laboratory equipment consisted of ordinary PCI instruments and an aorta model from the Valsalva sinus to the descending aorta. A Wolverine™ cutting balloon catheter was advanced through each lesion model via a guide catheter set into the system. The maximum force required to push the catheter through the lesion models was measured while the vessel system was filled with either normal saline or contrast medium. The maximum force required was significantly lower with the contrast medium (1.38 ± 0.21 N in the normal-saline condition vs. 0.92 ± 0.05 N in the contrast-medium condition in the lesion model A, p < 0.001; 1.30 ± 0.07 N in the normal-saline condition vs. 1.14 ± 0.04 N in the contrast-medium condition in the lesion model B, p < 0.001). CONCLUSIONS: The contrast medium for vessel system filling reduced the force required to push the devices through the lesion models. This contrast medium represents a potential candidate for a liquid lubricant to facilitate device delivery for complicated coronary lesions.