Effect of the Balloon Size on Lesion Formation During Visually Guided Laser Balloon Ablation in an In Vitro Model.

BACKGROUND: It is unclear whether balloon size can influence lesion formation. The aim of this study was to evaluate the impact of balloon size on lesion formation during laser balloon procedures in an in vitro model.Methods and Results:Laser energy was applied to chicken muscle using a first generation laser balloon. Laser ablation was performed with 2 different balloon sizes (18 mm and 32 mm) using 2 different power settings (12 W/20 s and 8.5 W/20 s) on the chicken muscle. The lesion characteristics, including maximum lesion depth, maximum lesion diameter, surface diameter and depth at maximum diameter, were compared between the 18-mm and 32-mm balloon groups at 12 W/20 s and 8.5 W/20 s, respectively. We created 40 lesions using laser energy at 12 W/20 s and 80 lesions at 8.5 W/20 s. At both power settings, the maximum lesion depth and the depth at the maximum diameter were larger in the 18-mm than in the 32-mm balloon group. At both power settings, the maximum lesion diameter and the surface diameter were smaller in the 18-mm than in the 32-mm balloon group. CONCLUSIONS: The balloon size could affect the lesion formation during laser balloon ablation. The lesion with the larger balloon size was wider and shallower than the lesion with the smaller balloon size.

Small balloon strategy associated with low pacemaker implantation rate after self-expanding transcatheter valve implantation.

BACKGROUND: This study aims to investigate whether small balloon aortic valvuloplasty (BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation (TAVI). METHODS: This was a retrospective analysis using data from our local TAVI database. Small BAV was defined as a small balloon size (=18 mm) pre-dilatation. Normal BAV was defined as a balloon size >18 mm. The primary endpoint was the incidence of new PPMI. RESULTS: Of 99 consecutive TAVI patients, five patients were excluded due to pre-existing permanent pacemaker. Patients in the small BAV group (n=57) had a significantly lower PPMI rate compared with the normal BAV group (n=37) (3.5% vs. 18.9%, P=0.026). Moderate or severe aortic valve regurgitation post-procedure was similar between the small BAV and normal BAV groups (5.3% vs. 8.1%, P=0.480); likewise, the mean aortic gradient post-procedure did not differ significantly (11.5±5.2 mmHg vs. 12.2±7.3 mmHg, 1 mmHg=0.133 kPa, P=0.580) between the groups. Device success rates were also similar (94.7% vs. 91.8%, P=0.680). In multivariable analysis, small BAV (P=0.027), the ratio of prosthesis diameter to annulus diameter (P=0.048), and mean aortic gradient by echo in the basement (P=0.021) were independent predictors of PPMI. CONCLUSIONS: The small BAV strategy is associated with a low rate of permanent pacemaker implantation after transcatheter self-expanding valve implantation in this single-center observational study.