Laser ablation of angioplasty catheters and balloons

A dilatation balloon (20,98) is fabricated according to a process that yields high hoop strength and uniformity in balloon wall thickness. A length of tubing (34) is axially elongated and radially expanded in a form (36) to provide the requisite biaxial orientation and strength. Then, an excimer laser (46,66,84) is used to remove the polymeric material by photo-chemical ablation, virtually without thermal effects. Dilatation balloon walls are thinned primarily along tapered sections (26,28) between proximal and distal balloon stems (30,32) and a medial working section (24) of the balloon. Material removal, particularly near the balloon stems, enables tighter wrapping of the balloon for a reduced delivery profile, and reduces rigidity near the stems for better maneuverability of the catheter in tortuous passageways. The balloon tapered sections are reduced to a wall thickness substantially equal to that of the medial section. Alternatively, an array of grooves (96) is formed in each tapered section.