INTRAVASCULAR ULTRASOUND IDENTIFICATION OF STENT ENTRAPMENT IN-VIVO WITH IN-VITRO CONFIRMATION

Objectives: One potential complication of stenting is ''stent jail'' d ue to placement of a stent across a side branch, which may impede addi tional interventions. Another form of stent entrapment may occur if th e guidewire is accidentally withdrawn and then unknowingly passes thro ugh a stent loop during reentry with subsequent high pressure expansio n, The purpose of this study was to evaluate this form of stent entrap ment in vitro by intravascular ultrasound (IVUS), Methods: A guidewire was passed through the end or middle diamonds of Palmaz-Schatz and Pa lmaz stents or the middle of Gianturco-Roubin stents, A 3.5 mm balloon was inflated over the guidewire through the various side holes of the stents, Results: IVUS images presented three distinct patterns depend ing on the type of stent and position of balloon entry: 1) external co mpression and loss of wall continuity in the Palmaz-Schatz and Palmaz stents, 2) displacement of the side diamond across the lumen, and 3) e xternal compression of the Gianturco-Roubin stent. The first and secon d patterns but not the third one were associated with impairment of lu men access, Conclusions: Based upon this in vitro verification, IVUS i maging can be used to Identify the presence of stent entrapment in viv o. (C) 1997 Wiley-Liss, Inc.