Repeated stenting of recurrent in-stent restenotic lesions: intravascular ultrasound analysis and clinical outcome.

Background: Stents are used to treat the first and even successive episodes of in-stent restenosis (ISR).

Methods: In 18 patients (19 lesions), intravascular ultrasound (IVUS) was performed after placement of a stent for a nonrestenotic lesion after the second stent was used to treat the first episode of ISR and after the third stent was used to treat the second episode of ISR. The duration between the first and second stent was 355 +/- 374 days, and between the second and third stent was 330 +/- 279 days. The duration of follow up after the third stent was 307 +/- 145 days. High-pressure inflation (> 14 atm) was performed for 69% (11/16) of patients when treating the first episode of ISR, and all patients when treating the re-ISR (p = 0.018).

Results: Nevertheless, vessel area and final minimal stent area (MSA) did not increase with successive restenting, and the ratio of minimum stent diameter to nominal stent size suggested that chronic stent underexpansion persisted. MSA > 5 mm2 was noted in 54% after the first stent, 35% after the second stent, and 42% after the third stent (p = 0.6). After the third stent, the rate of target lesion revascularization was 26% (5/19) and target vessel revascularization was 37% (7/19); there was 1 nonfatal myocardial infarction. Thus, the overall rate of major adverse cardiac events was 42%.

Conclusion: While serial restenting a recurrent ISR lesion was not associated with progressive decrease in MSA, it was still associated with chronic stent underexpansion and a high rate of adverse events. Attention should be directed to achieving better stent expansion to minimize subsequent recurrences.