As with catheters, there are a number of different varieties of balloon used in the Cath Lab; each type with a different purpose.
Pre-dilatation balloons are deployed and inflated to widen an area of stenotic coronary artery prior to the use of a stent. Advanced over a guidewire, the balloon itself is book-ended by two markers, allowing the operator to properly position the device before inflation.
Balloons are measured using their width and diameter, and each size has a nominal pressure to which it can be inflated. Balloons are normally inflated and deflated a number of times, with the pressure being increased with each deployment.
Balloon inflation aims to flatten the plaque against the artery wall, which both opens the artery, and enables stents to be passed through the vessel with greater ease.
Post-dilatation balloons are deployed after the above pre-dilatation balloons, often after a stent has been installed. Their more rigid build allows for widening of the stent more than the balloon it was initially mounted upon. This helps “cement” the stent against the outer lumen of the vessel, and lowers the risk of restenosis.
Cutting Balloons contain small blades on the outside of the balloon itself. When not deflated, these blades are nestled within the balloon which folds around them, and they only protrude as the balloon inflates. This model allows the apparatus to be safely passed through the artery without damaging any of the healthy areas.
Cutting balloons score the plaques within the artery, making them weaker, and more susceptible to further treatment.