Do we need another modality for truncal vein ablation?

Chronic venous disease (CVD) is a common clinical problem affecting 30%–40% of people in their lifetime. Varicose veins have previously been erroneously considered as a cosmetic problem, but we now know that these frequently cause discomfort, pain, loss of working days, disability and deterioration of health-related quality of life (QoL). Approximately 1% to 4% of the diseased population has a healed or active venous stasis ulcer, representing a significant burden to patients and costing up to 1% of the annual healthcare budget of Western societies. ¹

When the cause of CVD is incompetence of the great saphenous veins (GSV) or, less frequently, the small saphenous veins (SSV), intervention offers the best long-term outcome. For many years, high ligation of the saphenofemoral junction and stripping of the truncal vein were considered the gold standard method for treating saphenous reflux, but recurrence rates of up to 30%–40% were seen after five years. ² Such outcomes, coupled with procedural pain and complications, have driven the recent endovenous revolution since 2001. Long-term data to identify differences in recurrence is limited; nonetheless, it is starting to delineate the methods with more favourable rates. ³

The ideal modality to treat truncal veins would be one that can correct reflux without pain, complications (wound infection, thrombosis or skin pigmentation) or recurrence. It should be cost-effective and able to be performed in the office. But what about a modality that, in addition to having the aforementioned characteristics, can correct the reflux by preserving the vein? ⁴ This modality would be usable if a coronary or lower limb bypass is necessary. In 2015, Dr Chris Ragg described a technique to treat the saphenous vein reflux by reducing its lumen using injectable perivenous hyaluronan solution which provides invisible vein compression, but limited data are available.

In the United States, traditional surgical therapy for saphenous insufficiency has largely been supplanted by endovenous thermal ablation techniques, namely radiofrequency ablation (RFA) and endovenous laser ablation therapy.

With this change to minimally invasive techniques, patients can be treated in the outpatient setting, which reduces procedural cost with equivalent or superior outcomes compared with open surgical techniques. This has not only allowed frail patients to have appropriate therapeutic procedures with minimal complications but has also resulted in physicians from non-surgical specialties treating superficial venous disease. This is partly due to the transferable skills of the endovascular Seldinger technique.

Endovenous thermal ablation utilises either laser, radiofrequency or steam to generate thermal energy. This thermal energy then denatures the vein wall. In general, this is used in truncal veins and must utilise tumescent anaesthesia to act as a heat sink and anaesthetic. Laser ablation has demonstrated GSV ablation rates of over 93% at three years with improvement in symptoms. Multiple different laser wavelengths have been investigated and promoted by different companies and research teams, without clear evidence of superiority. RFA has shown equivalent occlusion rates with an improved pain profile. ⁵ Steam ablation has limited data but appears to show a similar profile to laser ablation.

Thermal ablation techniques have low rates of thrombotic events, deep venous thrombosis in roughly 0.3% of cases and pulmonary embolism in 0.1%. ⁶ But due to the use of thermal energy, these procedures have also other complications such as prolonged pain, ecchymosis and, less commonly, neuralgia and skin burns.

Newer non-thermal and non-tumescent (NTNT) ablation techniques which include cyanoacrylate closure (VenaSeal™, Medtronic Ltd, Galway, Ireland, Variclose, Biolas Ltd, Ankara, Turkey and VeinBlock, Invamed, Ankara, Turkey) and mechanochemical ablation (MOCA) (ClariVein™, Merit Medical, UT, USA) may avoid the associated negative effects of thermal methods.

Three-year follow-up data from the VeClose study were recently published; GSV closure rates were comparable to RFA, and Cyanoacrylate closure was found to be non-inferior to the endothermal technique. Significant improvements in the Venous Clinical Severity Score and QoL from baseline to six months were maintained at 36 months. ⁷

On the other hand, MOCA combines mechanical damage to the endothelium by a rotating wire with simultaneous catheter-guided infusion of a liquid sclerosant, which causes irreversible damage to the endothelium, resulting in vein fibrosis. This modality causes less postoperative pain but more hyperpigmentation when compared with RFA, with similar clinical outcomes at two years. ⁸

Venous sclerotherapy has been described as a low-cost and effective method to treat saphenous reflux, using sclerosing agents such as sodium tetradecyl sulfate, polidocanol and hypertonic saline. For many years, physicians have compounded liquid sclerosants into foam, typically made using nitrogen-rich room air, which has been associated with rare neurological adverse events. Polidocanol endovenous microfoam 1% (Varithena™, BTG International Ltd), an FDA-approved agent, has shown good results with adverse events generally mild, due to the absence of nitrogen. ⁹

A new modality (high-intensity focused ultrasound, SONOVEIN, Theraclion, Paris, France) was recently announced; ¹⁰ it can treat reflux without incisions, anaesthesia or needles, is completely non-invasive, and can be performed in the office. The early results show successful ablation of GSV, anterior thigh vein, incompetent perforators and neovascular tissue. Structures within 5 mm of the skin may need tumescence. This new device appears to offer the prospect of an ideal modality; however, formal studies with long-term follow-up are needed.

Despite the wide range of devices available nowadays, there is no consensus on which is best for each particular patient, in terms of cost effectiveness and which is best suited to the patient’s preferences. Undoubtedly, the new NTNT devices represent a great advance in terms of QoL for the patient, especially for the procedures that are carried out on an outpatient basis, since the patient does not receive the multiple needle punctures required by tumescence.

Currently, it appears that the need for another modality for truncal vein ablation is limited; however, we need better and longer term follow-up data to delineate the safety and efficacy of the modalities that are already available while new treatments are being developed. This will allow sensible plans moving forward, to ensure that the best treatment is tailored to the patient.