UCLA

Objectives

One potential complication of stenting is "stent jail" due to placement of a stent across a side branch, which may impede additional interventions. Another form of stent entrapment may occur if the guidewire is accidentally withdrawn and then unknowingly passes through a stent loop during reentry with subsequent high pressure expansion. The purpose of this study was to evaluate this form of stent entrapment in vitro by intravascular ultrasound (IVUS).

Methods

A guidewire was passed through the end or middle diamonds of Palmaz-Schatz and Palmaz 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 depending on the type of stent and position of balloon entry: 1) external compression and loss of wall continuity in the Palmaz-Schatz and Palmaz stents, 2) displacement of the side diamond across the lumen, and 3) external compression of the Gianturco-Roubin stent. The first and second patterns but not the third one were associated with impairment of lumen access.

Conclusions

Based upon this in vitro verification, IVUS imaging can be used to identify the presence of stent entrapment in vivo.