Mechanochemical Endovenous ablation (MOCATM) versus radiofrequency ablation (RFA) in the treatment of primary Small Saphenous vein Insufficiency: a multicentre randomized trial

Varicose veins are a common problem in the Western world. Epidemiological
studies show that 25% of adults have some characteristics of varicose veins.
Women are two to three times more affected than men. The incidence of varicose
veins increases steadily with age and are among the top ten of the complaints
that people visit their GP. The main risk factors include prolonged standing or
sitting, pregnancy, sex and age1. Symptoms of varicose veins are variable and
range from cosmetic complaints to venous ulcers2.These problems are mostly
associated with insufficiency of great saphenous veins (GSVs); however,
insufficiency of the small saphenous vein (SSV) is responsible in 15% of
patients with varicose veins.3
Until the 1990s, high ligation, with or without surgical stripping, was the
preferred option for venous insufficiency, although there was no standard in
surgical treatment of SSV insufficiency.4Recurrence of varicose veins after
conventional surgery is common.5,6 Recurrence rates of 25-50% are found
following surgery after a follow-up period of three to five years7-9In
addition, surgery can leads to significant postoperative symptoms, particularly
pain and hematoma formation. In surgical treatment of SSV insufficiency injury
to sural and peroneal nerve is a major concern.
The introduction of minimally invasive endothermal catheter modalities,
including endovenous laser ablation (EVLA) and radiofrequency ablation (RFA),
has revolutionized the treatment of varicose veins. These have become the
preferred techniques, with higher success rates7-9. The success rates of
endovenous ablation by RFA are frequently studied in GSV. Occlusion rates in
SSV are thought to be approximately similar to those in GSV. Van de Bos et al
showed in their meta-analysis occlusion in 88% of treated veins at 1 year
follow up. Thermal ablative techniques, which use heat as treatment source, can
be performed with local anesthesia. In SSV sural nerve injuries after thermal
ablation are described in up to 11%10. For this reason, patients are treated
with tumescence anaesthesia, which requires multiple punctures around the vein.
With tumescence anesthesia a liquid column is injected around the vessel, which
is a painful experience by most patients. Despite tumescence anesthesia
postoperative pain is inherent to thermal therapies and can last up to
weeks.RFA causes less hematoma formation, pain, and superior cosmetics and
earlier resumption of normal activities and work compared to traditional
surgical stripping11-12.

A new innovative technique, mechanochemical endovenous ablation (MOCATM), using
the ClariVein® system is recently developed. This technique uses a rotating
wire in a catheter to create mechanical damage to the endothelium of the
vessel. Simultanously a sclerosans is injected at the end of the catheter,
occluding the vein. With MOCATM no heating of the vein is used. Tumescence
anesthesia is redundant and complications that occur in thermal ablative
modalities, such as pain, hematoma formation, induration and paresthesias could
be reduced.
In Europe, the ClariVein® device is registered on April 26, 2010, CE 558723.

Two studies describing the safety and the initial results of MOCA* were
recently published. Elias et al.13 showed an occlusion rate in GSV of 96.7%
after MOCA*using sodium tetradecyl sulfate (Sotradecol®). The average follow-up
in these patients was 260 days. MOCA* combining Clarivein® with polidocanol
showed occlusion in 97% of treated GSV at 6 weeks after treatment, and partial
recanalisation was described in 10%. No major complications occurred, and minor
complains were acceptable in amount and severity13,14.Our study group recently
described the first results of MOCA* in SSV. MOCA* of SSV is a feasible and
safe treatment. Occlusion rates are 100% at 6 weeks follow up and 97% at 1
year. In SSV no major complications were seen, especially no nerve injury.
Minor complications were similar to those in GSV. Pain scores were low (2; IQR
2-4). The 'Venous Clinical Severity Score ", an objective measure of varicose
vein-specific symptoms improved significantly from 3.0 (interquartile range
[IQR] 2-5) before treatment to 1.0 (IQR 1-3, P< 0.001) at 6 weeks and to 1.0
(IQR 1-2, P< 0.001) at 1 year after treatment. Patients were satisfied after
treatment with an average of 8.8 (0-10 point scale)15.

Objective: To evaluate the anatomical success of MOCA versus RFA in treatment
of symptomatic insufficient SSV.

The MESSI study is a randomized controlled, multicentre trial, initiated by the
St. Antonius Hospital. The following Dutch hospitals will participate in the
study:
- Rijnstate Hospital, Arnhem
- Rode Kruis Ziekenhuis Beverwijk
- St. Antonius Hospital, Nieuwegein
Other centers may be invited to participate in the study.

"Experimental"
- Mechano-chemical ablation of insufficient SSV

"Control"
-Radiofrequency ablation of insufficient SSV

Both experimental and control intervention are accepted therapies in treatment
of insufficient SSVs.