Open-cell design stents in congenital heart disease: A comparison of IntraStent vs. Palmaz stents

Slotted stainless Palmaz stents (PS) remain the most commonly used in congenital heart disease (CND). Limitations of PS include rigidity, foreshortening, poor conformability on expansion, balloon rupture, and jailing of side branches. Recently, stents with open-cell design (IntraStent; IS) in appropriate sizes for CHD have been introduced. We reviewed our experience with the IS, comparing performance with the PS in a retrospective nonrandomized, uncontrolled observational study. Between May 1999 and March 2001, 34 IS (10-36 mm) and 34 PS (10-40 mm) were implanted in 57 patients (3 months to 25 years old; median, 3.24 years) in congenital or postoperative lesions. There was no statistically significant difference between the two groups in efficacy, % diameter increase (162% +/- 203% for IS vs. 153% +/- 177% for PS), and % gradient reduction (69% +/- 23% for IS vs. 80% +/- 27% for PS). Other aspects of stent performance differed significantly (P < 0.05): PS forshortened more (mean 18% for PS vs. 0% for IS) and were associated with balloon rupture (9/34 for PS vs. 0/34 for IS; P = 0.002), but had no evidence of intimal protrusion in between struts (0/34 for PS vs. 14/34 for IS; P < 0.001) and no recoil > 15% (0/34 for PS vs. 7/34 for IS; P = 0.006); IS conformed almost twice as well to vessel curvature (P = 0.003). Although these factors did not affect immediate procedural success, balloon rupture in two PS resulted in stent malpositions. Among IS, the origins of three covered side branches were accessed and balloon dilated up to 6 mm through the side of the stent. In conclusion, stents with open-cell design have some characteristics that seem beneficial for their use in CHD: they foreshorten less, are conformable, are less likely to cause balloon rupture, and can allow access to jailed branches. However, they have a higher incidence of significant percent recoil and protrusion of intimal tissue in between struts, which may impact long-term stent performance.