Crossing the line: different techniques, same results.
The investigators examined three different studies (Santangeli et al. 6, Li et al. 7 and Sanget al. 8) including a total of 64 patients. The follow-up duration ranged from 6 to 22 months, and three different types of devices were utilized (Amplatzer™, Abbott Medical, Plymouth, Minnesota ; CardioSEAL®, NMT Medical, Inc., Boston, Massachusetts ; Lifetech septal occluders, Lifetech Scientific, Shenzhen, China ). Acute procedural success (elimination of all pulmonary vein potentials and non-pulmonary vein triggers) was reached in 98.4% of patients (in 1 patient mitral isthmus block was not effective), showing a global feasibility of catheter ablation procedures in this population. The transseptal access was obtained through the native septum in the majority of patients (81.3%); direct puncture of the device was safe but resulted in a significant prolongation of procedural times. Two strategies were used to facilitate the access into the left atrium through a septal device: Santangeli et al. 6 placed an extra-stiff guidewire (0.032 inch) in a left pulmonary vein and advanced an upsized dilator (11 Fr) over the wire to further dilate the access site across the device, Li et al. 7 and Sang et al. 8advanced an angioplasty guide wire in the left superior pulmonary vein, withdrew the 8 Fr dilator, and performed sequential dilatations using a 2.5–5.0 mm non-compliant balloon under pressure of 12–18 atm to ease sheath manipulation. Current data do not show differences in the two approaches; sequential dilations may reduce the mechanical force that theoretically can result in device dislodgment, although no such event was reported by Santangeli et al. 6.
Neo-endothelialization and fibrous incorporation of the ASD closure device are generally completed within 1 to 3 months and, as described in a swine model9, 100% of the ASDs are generally closed at 3 months. Median times from ASD closure to catheter ablation in the three cohorts were 46 (6-82), 16 (6-36), and 11 (6-72) months respectively and this, apart from TSP techniques and operator skills, may have had a crucial role in determining the absence of device dislodgement, implying that catheter ablation might be safe at least 3 to 6 months after percutaneous ASD closure. Robust data on safety of direct puncture through other common devices (i.e. Gore® Cardioform Septal occluder and ASD occluder, W.L. Gore & Associates, Inc., Phoenix, Arizona ) are lacking and should be investigated, although an early animal experience seems encouraging since left atrial access was achieved in sixteen canines without acute complications10.