When deciding on a varicose vein procedure in the below-knee (BK) region, we need to consider whether to perform the procedure at all. An important judgment criterion in this decision is whether to prioritize objective, quantifiable data (for example, venous reflux on ultrasonography) or the patient’s subjective symptoms and quality of life.

According to a recent guideline for the treatment of the great saphenous vein (GSV), endovenous ablation is recommended over high ligation and stripping [1]. This recommendation is based on subjective data such as post-procedure pain and quality of life, including an earlier return to regular activities. Additionally, the guideline recommends both thermal and nonthermal ablation from the groin to below the knee. These recommendations have a strong level of endorsement (grade 1) and relatively high-quality evidence (B). Another guideline indicates that ablation to the lowest point of reflux in the BK GSV results in better early outcomes [2]. Furthermore, nonthermal procedures are preferred for ablation in the distal calf to avoid thermal nerve injury, though these recommendations are based on consensus statements.

For the treatment of BK reflux of the GSV, including concomitant above-knee (AK) reflux (with or without saphenofemoral junction [SFJ] reflux), the decision to proceed with treatment should be discussed in terms of both objective and subjective data. Isolated BK reflux of the GSV was excluded from this article.

The rationale for treating BK GSV reflux has been previously presented [3-5]. Labropoulos et al. evaluated 217 patients with superficial venous insufficiency using duplex ultrasonographic examination. They found that isolated BK GSV reflux was associated with more symptoms and signs than isolated AK reflux [3]. Another study by Labropoulos et al. found that superficial truncal reflux can occur in any segment, with the most common region being the BK GSV [4]. Fassiadis et al. found that of 454 limbs that showed GSV reflux on ultrasonography, 240 exhibited reflux of both the GSV and the SFJ, while 214 limbs (35%) showed isolated GSV reflux with a competent SFJ. They suggested that reflux starts distally and progresses proximally [5].

Although treating BK GSV carries the risk of various complications, studies have suggested that endovenous thermal ablation of the BK GSV is relatively safe. Proper management of BK GSV reflux has been shown to improve symptoms and reduce the need for additional treatments compared to ablation of the AK GSV alone [6-9].

A randomized controlled trial enrolled 68 limbs of 65 patients with varicose veins and divided them into three groups: EVLA (endovenous laser ablation) of the AK, EVLA to the BK mid-calf, and AK EVLA with concomitant BK foam sclerotherapy [8]. The Aberdeen Varicose Vein Severity Score (AVVSS) at 6 weeks improved in all groups. Compared with AK EVLA, concomitant BK ablation (either laser or sclerotherapy) resulted in fewer varicosities and superior symptom relief at 6 weeks.

Timperman evaluated 50 patients with complete GSV reflux who complained of ankle pain and swelling [7]. These patients underwent EVLA in the AK and BK GSV in either separate or the same sessions. All patients experienced resolution of their ankle pain, and most (44 patients) had resolution of swelling after 11 months.

In addition, other objective data support the treatment of BK GSV. A systematic review analyzed 15 randomized controlled trials from 2000 to 2020 [10]. These studies included 6 AK-HLS (high ligation and stripping), 7 AK-EVLA, and 2 AK+BK-EVLA. Sussman et al. revealed that AK-BK EVLA was associated with significantly lower odds of BK-GSV reflux recurrence compared with AK-EVLA alone (p<0.0001).

Another study emphasized the necessity of BK GSV treatment [9]. The authors treated 69 limbs, including 40 with C2 lesion, using AK EVLA. They assessed reflux in the BK GSV and categorized limbs into three groups: Group A had no reflux, Group B had flash reflux lasting <1 second, and Group C had significant reflux lasting >1 second. Delayed foam sclerotherapy for residual reflux was required in 12% of Group A, 14% of Group B, and 89% of Group C. At 6 weeks, the improvement in AVVSS was 86.2% in Group A, 82.1% in Group B, and 59.1% in Group C (p<0.001 vs. A and B). The authors suggested that persistent reflux in the BK GSV resulted in the least improvement of symptoms due to antegrade tributary flow.

Another consideration is the use of endovenous non-thermal and thermal techniques for BK GSV treatment. Non-thermal techniques are preferable when there are concerns about adjacent saphenous nerve injury. Recently, Jimenez et al. reported a high closure rate (96%) and a high ulcer healing rate (64%) using an endovenous microfoam ablation procedure for below-knee superficial truncal veins [11]. Although this recommendation is based on expert opinion (consensus statement), the guideline notes that non-thermal techniques are preferred for ablation of refluxing distal calf saphenous veins to avoid thermal nerve injury [2].

However, there are also reports indicating the safety of thermal ablation techniques. Gifford et al. treated 79 limbs with BK-GSV endovenous ablation and reported that only three patients (4%) experienced transient paresthesia [6].

Historically, ablation of the incompetent GSV was typically performed from the knee to the groin, omitting treatment of the BK GSV due to concerns about saphenous nerve injury [12,13]. These approaches emphasized potential risks rather than benefits of treatment. Furthermore, several studies have noted missing data on duplex ultrasonography, often reporting persistent residual reflux in the BK GSV after AK GSV ablation [14-16].

There has been a recent argument that treatment of the AK GSV alone may be sufficient. Studies have shown clinical improvement and enhanced quality of life regardless of the reflux status of the BK GSV in the treatment of incompetent GSV [17]. The author’s standard approach involved high ligation and stripping or endovenous thermal ablation of the AK GSV combined with additional stab avulsion of visible tributary varicosities. Despite persistent preoperative reflux in the BK GSV in half of the limbs post-treatment, subjective outcomes improved.

Despite the aforementioned evidence, many surgeons in the Republic of Korea continue to perform BK GSV treatment [18]. A survey was conducted among 45 surgeons with over 10 years of experience in treating varicose veins. They were asked about their therapeutic approach for thermal ablation when treating reflux throughout the GSV. The results were as follows: AK GSV, 37%; BK GSV, 42%; treatment to the ankle level, 9%; and maximal segment based on sonographic evaluation of the relationship between the GSV and the saphenous nerve, 12%. About one-third of surgeons focused only on AK GSV treatment, while the remainder also treated BK GSV. In addition to concerns about nerve injury, attention was paid to complications such as hyperpigmentation and skin burns.

Determining the appropriate extent of treatment for incompetent varicose veins presents significant challenges. Current guidelines lack clear definitions, and existing evidence or rationale remains insufficient. It would be preferable to adopt a personalized treatment approach for each patient, carefully evaluating outcomes based on both subjective and objective data. Further research is necessary to establish the validity and evidence supporting the optimal treatment extent for incompetent varicosities. Additionally, future studies could explore whether treatment plans could be stratified based on factors such as the presence of BK perforators, types and duration of symptoms, and characteristics like BK reflux time or velocity.

The author declares no conflicts of interest.