We read with great interest the original article by Kim et al. (1) entitled "Retrograde Endovenous Laser Ablation through Saphenopopliteal Junctional Area for Incompetent Small Saphenous Vein: Comparison with Antegrade Approach", which was published recently in the Korean Journal of Radiology (KJR), 2016;17(3):364-369. In the study, the authors evaluated the safety and efficacy of retrograde endovenous laser ablation (EVLA) as compared with the conventional antegrade EVLA for incompetent small saphenous vein (SSV).

The authors used retrograde access after two unsuccessful attempts with antegrade access. However, they did not discuss the reasons for the failed attempts in detail such as in the cited literature (2). Knowledge of the exact reasons is important for appropriate measures to overcome potential problems. In our practice, for cases of small vessel caliber or vasospasm during the procedure apart from the other uncommon reasons, we use a simple valsalva maneuver to distend the vein with high success rate. Dangling the cruris is another simple positioning in the problematic EVLA procedures we encounter. Micropuncture set is reportedly the method with highest success rate (3). We often apply this technique to succeed in the antegrad approach. Moreover, the SSV insufficiency usually accompanies great saphenous vein insufficiency; and the vessel caliber is substantially greater than 5 mm (4). Discussing these methods in their publication would have contributed valuable information about the technique.

In addition, the authors reported that 37 patients and 44 limbs underwent EVLA after retrograde access in the results section. On the other hand, they emphasized that they had failed to obtain antegrade access in 45 limbs in the discussion section. Hence, the final situation of one limb in which they had failed to obtain antegrad access is unclear and no data is reported on any attempt to obtain retrograde access. Addressing this point and the final decision of this case would avoid misleading the readers.