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.