Importance of balloon size in coronary angioplasty

Abstract

The effect of balloon size on the success of coronary angioplasty was studied to develop quantitative criteria for optimal selection of balloon size. Coronary dimensions of 165 stenotic lesions were measured by computer-assisted cinevideodensitometry in 120 patients who had undergone angioplasty with a balloon selected by visual estimates. Cross-sectional areas and diameters of normal and stenotic arterial segments were measured before and after angioplasty by a previously validated cinevideodensitometric technique. The diameter of the inflated balloon compared with that of the normal arterial segment was expressed as a ratio for sizing balloons. Oversized balloons with a ratio greater than 1.3 (n = 35) caused a high (37%) incidence of dissection, with three severely compromised arterial lumens. Undersized balloons with a ratio less than 0.9 (n = 29) often resulted in significant (greater than 50% diameter stenosis) residual stenotic lesions (21%) and a significantly (p less than 0.05) higher rate of repeat angioplasty for restenosis. Selection of balloon sizes with ratios in the 0.9 to 1.3 range (n = 101) resulted in a low (4%) incidence of dissection with few patients (3%) having significant residual stenosis. Mean residual stenosis (percent diameter reduction) was most severe for undersized (35.0 +/- 18%) or oversized (23.1 +/- 19%) balloons and least severe for balloons with a ratio of 0.9 to 1.3 (18.7 +/- 14%) (p less than 0.001). Repeat angioplasty for restenosis was more frequently required (p less than 0.05) for lesions dilated with undersized balloons. Thus, selection of angioplasty balloons that approximate or slightly exceed the diameter of the normal arterial diameter yields optimal angiographic results with minimal dissections and minimal residual stenotic lesions.

A Call for Provisional Stenting

“…In the prestent era, despite the fundamental tenet in interventional cardiology that larger immediate postprocedural luminal diameters are associated with lower rates of restenosis, the fear of major dissection and its attendant sequelae served to limit the aggressiveness with which balloon dilatation could be safely performed. 21,22 With the knowledge that stents are "on the shelf," however, the interventionalist now has access to a "safety net" that in many instances can allow more aggressive attempts to optimize luminal gain via balloon dilatation. Furthermore, the availability and efficacy of platelet glycoprotein IIb/IIIa receptor inhibitors in reducing acute thrombotic complications of angioplasty have significantly improved the safety of balloon angioplasty.…”

Variability in estimation of coronary dimensions from 6F and 8F catheters

“…Indeed, selection of angioplasty balloon diameter is based on the size of the reference diameter of the diseased vessel, assuming that a 1: 1.1 balloon/artery ratio optimizes the success rate of the procedure [3,21]. Similarly, selection of stents or other interventional devices is guided by the "normal" reference diameter of the vessel.…”

Evidence for altered epicardial coronary artery autoregulation as a cause of distal coronary vasoconstriction after successful percutaneous transluminal coronary angioplasty.

“…The balloon size, ratio of inflated balloon diameter to diameter of adjacent normal artery, total number of balloon inflations, total duration of inflations and post-PTCA incidence of angiographic intimal dissection were not significantly different for the three lesion severity subgroups. A number of studies have demonstrated that the severity of arterial trauma after balloon angioplasty, as judged by the incidence of intimal dissection and acute closure after PTCA (15)(16)(17) or determined histologically after in situ angioplasty (18) or after angioplasty in the cholesterol fed rabbit model (19) is not necessarily related to the severity ofthe lesion being dilated. Severe vessel injury, for example, is often observed after balloon dilatation of moderate lesions (19).…”