Overestimation of stent delivery balloon diameters by manufacturers' compliance tables: A quantitative coronary analysis of Duet and NIR stent implantation

Abstract

Although manufacturers' compliance tables of stent delivery balloons indicate the diameter of the balloon at a given inflation pressure, it is unclear whether these data correlate with in vivo true intracoronary balloon diameters (TBDs). The TBDs of two new-generation balloon-expandable stent delivery systems (Duet and NIR) were measured by quantitative coronary analysis (QCA) in 100 consecutive patients. The manufacturers' stated balloon diameter (BD) of the stent delivery systems overestimated the TBD in 94% +/- 4% of patients receiving both Duet or NIR stent implantations. In only 6% of the patients, the TBD matched the manufacturers' stated balloon diameter. There was no underestimation of TBDs by both manufacturers' compliance tables. The Duet tables overestimated TBDs by 14% +/- 8% (range, 1%-36%), the NIR tables by 18% +/- 8% (range, 1%-41%), P < 0.05, Duet vs. NIR, respectively. When the manufacturers' data were corrected for the differences in reporting data from in vitro tests, i.e., balloon compliance data with or without the stent, the degree of overestimation of diameters was similar for Duet and NIR stent delivery balloons (14% +/- 8% vs. 13% +/- 7%, Duet vs. NIR; P = NS). Manufacturers' compliance tables of both the Duet and NIR stent delivery balloon systems significantly overestimate the true intracoronary balloon diameter. The manufacturers' of stent delivery balloons should clearly state on the box, if balloon compliance data were derived from in vitro bench testing, which phantoms were used for compliance analysis, and that the tables may overestimate the true intracoronary balloon diameter. The findings of the present study have important clinical implications with respect to performing coronary stent implantation with precision.

Stent expansion: a combination of delivery balloon underexpansion and acute stent recoil reduces predicted stent diameter irrespective of reference vessel size

“…The diameter of the stent delivery balloon during deployment will vary depending on the site at which measurements are made. Hehrlein et al 5 measured the MD of the stent delivery balloon during peak pressure, as in our study. They reported that the delivery balloon diameter of the Duet and the NIR stent delivery system were on average 14% and 18% smaller than predicted by the manufacturers.…”

Intravascular Ultrasound Assessment of Cobalt Chromium Versus Stainless Steel Drug-Eluting Stent Expansion

“…5,6 Manufacturers have provided a compliance chart reporting the implanted stent diameter as a function of the nominal stent size and deployment pressure. Although these charts were determined from in vitro measurements typically done in water, 7 interventional cardiologists have routinely relied on these charts to optimize the stent dimensions according to stent size and inflation pressure during percutaneous procedures. We have used the ratio of the intravascular ultrasound (IVUS)-measured stent diameter and area to that predicted by the manufacturers' compliance chart as a measure of acute stent expansion, including the effect of both expansion of the stent delivery balloon and acute stent recoil.…”

Compliance charts to guide non-complex small artery stenting: validation by quantitative coronary angiography

“…This group is at higher risk for restenosis and stent thrombosis19 20 and were excluded from previous analyses 1 2 4 14. We showed that there was actually less variation between the two measurement methods when final lumen diameters were <3 mm, implying that balloon compliance charts are even more reliable as a guide to non-complex stenting in smaller coronary arteries.…”

“…These charts are derived from in vitro testing in a water bath or related phantom at 37°C, as previously described 1. The accuracy of these charts based on in vitro measurements has been disputed by in vivo studies using quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) 1–4.…”