Dissections and Elastic Recoil Post Chocolate™ Balloon Catheter Treatment in Femoropopliteal Artery Lesions: Visions from Intravascular Ultrasound and 12- month following-up results

Purpose: Situations of vessel wall in IVUS images after Chocolate balloon dilatation remains unknown and 12-month following-up results would be performed. Materials and Methods 25 patients were enrolled in this observational study. Angiography and intravascular ultrasound were performed before Chocolate balloon inflation and post inflation. Dissections were quantified and classified according to the iDissection classification on intravascular ultrasound (IVUS) and National Heart, Lung, and Blood Institute classification on angiography. The elastic recoil rate, plaque burden and luminal gain were calculated in each patient too. Doppler ultrasound was presented in 30days, 3months, 6months and 12months each patient during follow-up. Results The mean lesion length was 168.3 ± 26.6 mm and arc of calcium was 115.1 ± 84.6°. 7 of the 25 patients required stents because of flow-limiting dissections and another 8 patients used stents with residual narrowing > 30%. Post Chocolate balloon angioplasty, the elastic recoil rate was 32.4 ± 13.1% and luminal gain was 6.1 ± 2.8mm 2 . The plaque burden volume reduction was 7.0 ± 4.6%. Diameters on cine were 5.1 ± 0.7mm and 5.9 ± 0.6mm on IVUS. Total number of dissections were 2.9 times (114/40) on IVUS images than cine film, more non-flow-limiting dissections observed on IVUS compared cine (102/31). 2 patients lost follow-up because of death, primary patency in patients was 52.2% (12/23) and secondary patency was 82.6% (19/23) in 12-month. Conclusion Vessel injury from Chocolate balloon angioplasty and diameter in femoropopliteal artery lesions were grossly underestimated on angiography. Severe elastic recoil performed in most of patients according to IVUS images after Chocolate. Further randomized controlled trials are needed to support their use.