Limitations
There are some limitations in our work that must be acknowledged. First,
results need to be interpreted as hypothesis-generating and in light of
the small and heterogeneous sample size, due to the use of different
imaging modalities and different ablation modalities.
No direct comparisons between ICE and IVUS were made by imaging the same
PVs with both modalities. No other imaging modality or histopathology
were available as reference for the PVs measurements obtained with ICE
and IVUS to ascertain which of the two imaging modalities gave more
accurate measurements. However, this did not preclude confirming the
feasibility of both ICE and IVUS for LA wall imaging, since comparable
wall thickness measurements were obtained and similar acute changes in
wall thickness were detected with both imaging modalities.
Pullback was manual rather than automatic. This precluded the precise
comparison of distal cross-sections before and after ablation.
Imaging during energy delivery was not attempted as the same
trans-septal access was used for either ablation catheter or imaging
catheter. However, simultaneous imaging might not have been possible due
to spatial interference, especially when using cryo or laser balloon
catheters, and/or due to artifacts created by irrigation of the RF
catheter.