Approach to an ISR due to stent underexpansion after LM to LCX crossover stenting

Operators:Assoc. Prof. Dr. Mutlu Vural
Dr. Ekrem Bilal Karaaymaz

Bağcılar Education and Research Hospital

Case History

A 58-year-old male patient who had previously  undergone bypass surgery  is scheduled for dominant LCX PCI procedure (Video 1). According to the size of the lesion, 4.0 × 32 mm BMS is placed after the pre-dilation with a small balloon (Video 2). Stent underexpansion is clear ( Figure 1). Post-dilatation with 4.0 short NC balloon ( Figure 2). He is discharged with residual stenosis (Video 3).


The patient is scheduled to undergo direct coronary angiography three months after the first procedure when his complaints resume and are more severe than before. LM-LCX stent has  severe ISR and severe LAD osteal stenosis that supply D1 (Video 4). Crossing the lesion with a floppy wire  through  6 Fr AL-2 guiding catheter and predilatation with a small balloon ( Figure 3). Then a 4.0 × 23 mm NC balloon is delivered (Video 5). Stent expansion is still insufficient after NC balloon dilatation ( Figure 4). When the NC balloon bursts at 35 atm in a forth attempt and distal stent overexpansion occurs, a new 4.0 × 15 mm short NC balloon is delivered ( Figure 5). Due to the previously restricted LAD flow severe angina developed and the LAD was wired (Video 6). In order to avoid destroying stent struts, the LAD flow was restorated  with a 1.25 × 9 mm balloon (Video 7). After the dilation of the second NC balloon with 35 atm 4 times and the better stent expansion was achieved ( Figure 5). Then a 3.5 × 20 mm drug balloon was delivered to the restenosis zone (Video 8). The result is acceptable and the process has been terminated because all available possibilities have been used (Video 9).


  1. Predilatation with 1: 1 balloons should be done before implanting a stent. Post-dilatation would be a more difficult effort when the stent is underexpansed.
  2.  When the stent is underexpansed, the risk of restenosis is high and the patient should be informed.
  3.  With NC balloons higher pressures could be tried carefully.
  4. If there are cutting balloons like angiosculp, it can help for predilation in tight lesions.
  5. If there is laser, a contrast-accelerated laser may help for stent optimization with an NC balloon.
  6. If acceptable expansion is achieved, reoccurring ISR can be prevented with drug-coated balloons .
  7. Healt insurance system should cover DES over 3.0 mm.

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Video 9

Figure 1

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