Making the difference
Kuroki et al have elegantly investigated if an improved semi-automated VGLA system could ameliorate the efficiency of this technology compared to manual manipulation of the catheter. They have clearly demonstrated in experimental setting that the mean lesion counts were significantly reduced by using the SA as opposed to MN (5.3±5.9 vs 33.7±10.0, P=0.007) . This proves an improved efficiency of SA over the MN approach. Moreover, the lesion counts resulted favorable also in comparison with RF ablation (28.0±4.4, P=0.019). The catheter use time resulted shorter for SA as compared to MN in both acute and chronic study (28.0±12.1 to 12.7±15.0 and 28.8±3.8 to 11.5±12.7 min). Of course this represents an important advantage for the efficiency of the approach and it might constitute the basis for obtaining a similar outcome even in the clinical setting. What I would consider quite a fundamental result is that the SA mode is the homogenous circumferentiality of the lesion and the transmurality demonstrated both in acute and chronic studies. This suggests that the uninterrupted movement provided by the SA with continuous energy application could promote an improved transmurality over the MN and also with less propensity to create gaps. The gross anatomy well shows the difference between the two modalities of laser ablation and support the value of the SA as the preferred mode of deploy laser energy.
The advantage of directly viewing the tissue is also revealed by the comparison between laser and RF application, being the level of RF application deeper in the vein. Therefore, one might conclude that SA laser modality of ablation ensures a higher level of proximal PV’s ostium lesion continuity, transmurality and less gap formation. The dose of 13 and 15 W in the current clinically available SA VGLA (5) seems adequate to promote effective lesions even in humans (6-8). The improvement of the VGLA system portraying the novel SA modality can be rightly considered an effective, efficient approach for achieving a high rate of PVI. We all know there are several new technologies and tools reaching the EP field, each of them aiming at successful and durable PVI. We need to applaude Kuroki and co-workers, since their effort was to show the consistency and the value of VGLA energy applied through a novel SA technique.
Needless to remind us that other initiatives are taking place in the EP field, led by researchers and companies as to identify the most successful ablative approach for PVI. Laser therapy is an attractive technology belonging to the family of balloon-based platforms and plays a crucial role in achieving this goal. Reasonably, comparative studies will be required to establish the relative merit to each proposed ablative treatment strategy