EARLY AND LATE ASSESSMENT OF THE MICRO-STENT-PL CORONARY STENT FOR RESTENOSIS AND SUBOPTIMAL BALLOON ANGIOPLASTY

This prospective study represents the initial assessment of the Micro Stent PL (Arterial Vascular Engineering, Inc.) coronary stent. From on e to three radiopaque stainless steel stents, each measuring 4 mm long , were premounted onto specially designed balloon catheters. A total o f 123 stents were implanted in 41 patients without procedural failure or complications. Stent dislodgment proved a concern, with 7 of 123 st ents (5.7%) moving >3 mm from the site of placement and late downstrea m migration occurring in an additional patient. Subacute stent thrombo sis occurred in two patients (5%). Six-month angiographic follow-up wa s available in 37 of 41 patients (90%). Minimal lumen diameter at base line was 0.93 +/- 0.51 mm, increasing to 2.74 +/- 0.49 mm after stenti ng, and falling to 1.66 +/- 0.89 mm at 6 months; this represents a lat e loss of 60% of the initial gain. Restenosis, based on a binary defin ition of >50% diameter stenosis, was documented in 18 patients (49%). Advantages of the Micro Stent PL include its radiopacity and marked ea se of distal delivery. The potential for stent dislodgment has implica tions for future stent designs. The role of the Micro Stent PL in mana ging restenosis is unclear, but it appears useful in the management of dissection and threatened closure after balloon angioplasty.