Traditionally, varicose veins were considered merely a cosmetic issue. However, findings from the REACTIV trial, a randomized controlled trial, revealed that patients who received the best medical treatment (graduated compression stockings) had a lower quality of life after two years compared to those who underwent treatment for their varicose veins (1). As a result, there has been an increasing use of endovenous treatment for varicose veins. Surgical stripping (SS) of varicose veins does not permanently remove the veins, as most of them grow back without valves during the healing process, leading to a recurrence of the same problem (2). Currently, there are various forms of endovenous treatment available for axial reflux. These include thermal ablation techniques such as endovenous laser ablation and radiofrequency ablation (RFA), as well as non-thermal ablation methods like cyanoacrylate adhesive closure (CAC), mechanochemical ablation (MOCA), and foam sclerotherapy. However, performing endovenous ablation can sometimes be challenging due to anatomical factors associated with the great saphenous vein (GSV), such as its shallow location which increases the risk of skin burn or superficial thrombophlebitis, as well as the possibility of leaving a palpable cord of the vein. The objective of our study was to assess the distribution of reflux along the GSV and determine the anatomical depth of the GSV. 

This retrospective single-center observational study was conducted between July 2009 and January 2022. It involved consecutive symptomatic patients with primary varicose veins and axial reflux caused by an incompetent great saphenous vein (GSV). The study took place at a university hospital with approval from the Institutional Review Board, adhering to the regulations outlined by the Declaration of Helsinki. Informed consent was waived due to the study's retrospective nature.

Ultrasound images of limbs affected by varicose veins were carefully examined to evaluate the distribution of reflux and the depth of the GSV. The study also included an examination of the access sites used during endovenous procedures. Limb scanning began at the Sapho-femoral Junction (SFJ) in the groin and extended to the ankle. The GSV was identified by its location in the “Egyptian eye” or fascial envelope. Reflux areas were identified at seven sites along the GSV: upper thigh (including SFJ, AK1), mid-thigh (AK2), lower thigh (AK3), knee, below-knee proximal (BK1), mid (BK2), and distal (BK3). Reflux was documented using a manual compression and release maneuver. The number of GSVs located deeper than 5mm at each site was counted. Categorical variables were presented as numbers and percentages, while continuous variables were expressed as mean±standard deviation after conducting the normality test (Kolmogorov-Smirnov test). If the data did not follow a normal distribution, the median and interquartile range (IQR) were reported instead. Statistical significance was set at p<0.05. All statistical analyses were performed using IBM Statistical Package for the Social Science (SPSS^®) version 25 (IBM Corporation, Armonk, New York, USA). 

The baseline patient characteristics are summarized in Table 1. A total of 549 limbs with GSV reflux in 450 patients were included in this study. The mean age was 53.6 years (standard deviation: 13.2). Bilateral treatment was performed in 49 patients (17.9%). The most distal part of the reflux is depicted in Fig. 1. The distal end of reflux was located in AK1 in 9 (1.6%) limbs, AK2 in 41 (7.5%) limbs, AK3 in 157 (28.6%) limbs, and below the knee (BK) segment in 290 (52.9%) limbs. The number of GSVs located deeper than 5mm from the skin at each measurement site is shown in Fig. 2. The depth of the GSV was greater than 5 mm in AK1 in only 25 (4.6%) limbs, from the junction to AK2 in 49 (8.9%) limbs, to AK3 in 82 (14.9%) limbs, to the knee in 22 (4.0%) limbs, below the knee in 75 (13.7%) limbs, and in the entire length of the leg in 296 (53.9%) limbs. The access sites for the endovenous procedure are shown in Fig. 3. The lower thigh was the most frequently accessed site. Additional microphlebectomy to remove superficially located truncal veins with reflux was performed in 145 (38.0%) limbs in the RFA group, 16 (12.4%) limbs in the CAC group, and 0 in the MOCA group.

Table 1

Baseline characteristics

	RFA	CAC	MOCA	SS
N	382 (69.5%)	128 (23.4%)	5 (0.9%)	34 (6.2%)
Age (mean [SD])	54.3 (13.2)	56.3 (12.0)	45.1 (10.4)	55.5 (12.0)
Sex (women)	214 (55.9%)	86 (67.2%)	5 (100.0%)	15 (43.7%)
C1	1	1 (0.8%)	0	0
C2	236 (61.7%)	74 (57.8%)	4 (80.0%)	16 (47.1%)
C3	135 (35.4%)	41 (32.3%)	1 (20.0%)	10 (29.4%)
C4	7 (1.9%)	5 (4.1%)	0	6 (17.6%)
C5	2 (0.5%)	3 (2.1%)	0	1 (2.9%)
C6	2 (0.5%)	3 (2.1%)	0	1 (2.9%)

RFA: radiofrequency ablation, CAC: cyanoacrylate adhesive closure, MOCA: mechanochemical ablation, SS: surgical stripping.

Fig. 1. The most distal part of the reflux on duplex ultrasound examina-tion.

Fig. 2. The number of GSVs located deeper than 5 mm from the skin at each measurement site.

Fig. 3. The access sites for the endovenous procedure. RFA: radio-frequency ablation, CAC: cyano-acrylate adhesive closure, MOCA: mechanochemical ablation.

For patients with symptomatic varicose veins and axial reflux in the great saphenous vein (GSV) who require intervention, endovenous ablation is the preferred treatment method over traditional saphenous stripping (SS), due to its minimally invasive nature and faster recovery time (3). Long-term effectiveness data from multiple prospective randomized controlled trials, including 5-year and 10-year follow-ups, are now available to assist physicians in making informed treatment decisions (4-7). Currently different techniques are available for treating incompetent saphenous trunks. Endovenous thermal ablation is generally recom-mended as the first-line treatment due to its excellent long-term results and cost-effectiveness (8). Non-thermal ablation techniques may offer lower rates of procedural pain and ecchymosis compared to thermal ablation (9). The choice of specific techniques depends on patient preference, local equipment availability, and the treating physician’s experience, considering similar efficacy and excellent long-term results (10). However, anatomical considerations, such as very large or superficial saphenous trunks, should also be taken into account when selecting treatment modalities (10). Patients should be informed about the potential risks of hyperpigmentation and transient induration when treating very superficial truncal veins (≤5 mm from the skin). Induration may persist for a prolonged period, even with non-thermal techniques such as CAC.

Preoperative ultrasound mapping is crucial for determining the extent of reflux along the GSV, minimizing unnecessary removal of non-refluxing segments and avoiding complica-tions associated with extensive surgery, including nerve damage. Venous reflux can be classified as segmental, multi-segmental, or axial, with axial and multi-segmental reflux being more prevalent in advanced stages of venous disease (11). Our study focused on axial reflux, justifying the removal of the entire length of refluxing segments. However, the shallow location of the GSV poses challenges when removing the entire length of refluxing segments. In such cases, phlebectomy may be a suitable alternative for very superficial veins, and sclerotherapy can be performed as an alternative to miniphlebectomy (3). The purpose of our study was to investigate the prevalence of situations requiring additional treatment techniques to remove shallowly located GSV. While the most distal part of reflux is typically found in the below-knee segment, only approxi-mately 50% of the GSV is located deeper than 5mm along its entire length. Therefore, preoperative ultrasound mapping for assessing the reflux extent as well as the depth of the GSV plays a crucial role in determining the optimal treatment method, as a quarter of patients may require additional phlebectomy or sclerotherapy to address superfi-cially located GSV. In these cases, physicians should thoroughly inform patients about the potential complications associated with the superficial location of the GSV.

In conclusion, while the most distal part of reflux is typically found in the below-knee segment, only approxi-mately 50% of the GSV is located deeper than 5mm along its entire length. Therefore, preoperative assessment of the reflux extent as well as the depth of the GSV is essential for accurate treatment planning and avoiding complications. Physicians should inform patients about potential risks associated with treating superficially located GSV, and additional techniques such as phlebectomy or sclerotherapy may be required for optimal outcomes. 

This study was supported by a grant from the Korean Society for Phlebology.