Histopathological study of mechanochemical endovenous ablation of the great saphenous vein

Varicose veins are a common problem in the Western world. Epidemiological
studies show that one quarter of adults have some form of varicose veins.
Women are two to three times more affected than men. The prevalence of varicose
veins increases steadily with age and is among the top ten of the complaints
that people visit their General Practitioner. The main risk factors are
prolonged standing or sitting, pregnancy, gender and age. The symptoms of
varicose veins are variable and range from cosmetic complaints to venous ulcers.
Stripping of the great saphenous vein(GSV) has been the golden standard for GSV
insufficiency for a long time. It is performed under regional or general
anesthesia and has a high recurrence rate of 18-40% at 5 years. In addition,
the procedure leads to significant postoperative symptoms, especially pain,
hematoma and the risk of injury to the saphenous nerve.
In recent years, endovenous techniques have been developed for the treatment of
primary GSV insufficiency. Particularly laser endovenous ablation (EVLA) and
radiofrequency ablation (VNUS) became accepted technologies and are widely
applied in practice. These thermal-based techniques have the advantage that the
surgery can be performed with local anesthesia. In addition, endovenous
techniques cause less hematoma, pain, and have superior cosmetics and earlier
resumption of normal activities/work compared to the conventional surgical
stripping.

Endothermal techniques use heat, which has potential risk to damage surrounding
tissues. For this reason, patients are treated with tumiscence anesthesia,
requiring multiple punctures around the vein. Most patients experience
tumiscence anesthesia as unpleasant. Despite the tumiscence anesthesia,
patients may still observe postoperative pain, which may last for weeks.
Laser energy is absorbed and converted into intraluminal heat. This process
causes steam bubbles, as described by Proebstle. In previous studies,
intraluminal and extraluminal temperature measurements were done during
endovenous laser ablation. In addition, acute pathological changes after
endovenous laser ablation is studied in a recent study. The loss of laser
energy was confined to the inner part of the media. No perivascular damage was
seen. However, 1% of patients treated with endovenous laser ablation has nerve
damage or paresthesias. It suggests that perivascular damage to some extent
still exists.
The effects of foam sclerosis appear to be limited to the endothelium and
tunica media of the vein wall. Pathological changes occur rapidly within the
first 2 minutes after treatment. After 30 minutes intimal detachment of the
tunica media, and the formation of microthrombi are detected. The addition of a
balloon injury of the vessel wall prior to foam sclerosis, results in a higher
percentage of endothelial damage. However, in practice, the clinical results of
foam sclerosis disappointing. The occlusionrate from 1 to 5 years were 81 and
73% in a recent meta-analysis.

A new technique, mechanochemical endovenous ablation (MOCA), using the
ClariVein ® system is recently developed. The first studies show that MOCA a
safe and effective treatment for varicose veins. This technique uses mechanical
damage to the endothelium of the vein wall through a rotating tip of the
catheter. At the same time a sclerosans is injected, causing occlusion of the
vein. No heating is used in this technique . Tumiscence anesthesia is redundant
and complications that occur in thermal endovenous techniques, such as pain,
hematoma formation, induration and paresthesias could be reduced. To date,
histopathological data after mechanochemical endovenous ablation are not known.

The aim of this study is the histopathological analysis of venous injury using
mechanochemical endovenous ablation

The Endovenous Histology study is a histopathological study on the effects of
mechanochemical endovenous ablation. The studycentre will be:
- Rijnstate Hospital, Arnhem.

5 patients with irreversible tissue damage to the lower extremities based on
atherosclerotic peripheral vascular disease will be included in the study
Endovenous Histology, after signing informed consent. All patients included,
are scheduled for an elective upper or underleg amputation. The preprocedural
status will be determined by height, weight, comorbidities, ASA classification,
medications, previous vascular surgery and venous duplex of the VSM.
Subsequently 5 patients are treated with MOCA of the VSM to the amputation
level prior to the amputation under general or spinal anesthesia.

MOCA is performed in patients with an intact venous circulation, who have been
planned for a upper or lower leg amputation due to peripheral arterial disease.
The operation is conducted under spinal or general anesthesia. Patients get
standard low molecular weight heparin in prophylactic doses on the evening
before surgery.
The VSM is marked with a pen across the lower leg under ultrasound guidance.
The amputated leg is disinfected with chlorhexidine 0.5% dissolved in 70%
alcohol. The foot is wrapped in a sterile base. The level of amputation and the
incision are marked with a pen. At the amputation level, the VSM is identified
and ligated, so no materials or products can enter the circulation.

On the medial side of the ankle, the VSM identified by a small incision. The
VSM is punctured and an introduction sheath is inserted. Then the ClariVein ®
catheter is inserted and increased to the ligature at the level of the
amputation level. In preparation, the VSM is identified each 5 cm from the
amputation level (total length 20 cm), allowing four segments to be easily
excised after treatment. Four segments of the VSM will be separately excised
for histological examination.
* Segment 1: control segment. This segment is only treated by mechanical damage
of the rotating catheter, without infusion of sclerosans
* Segment 2: excision after 2 minutes. This segment is excised after 2 minutes
MOCA
* Segment 3: excision after 15 minutes. This segment is excised 15 minutes
after MOCA
* Segment 4: excision after 30 minutes. This segment is excised 30 minutes
after MOCA

Segment 1 is treated by activation of the rotating wire without infusion of
sclerosans. After 5 centimeters of mechanical damage a ligature is tied to the
VSM, so the 2-4 segments can be treated with MOCA. In this way, segment 1 is
free of sclerosans.

MOCA is then performed on segments 2-4. The total volume of 3 ml Aethoxysklerol
sclerosans will be 2% (60 mg Aethoxysklerol), spread over 15 cm. This quantity
corresponds to a conventional treatment in practice. After the treatment
ligatures are placed between the segment 2-4. Two minutes after the ligatures
are placed, segment 1 and 2 are separately excised. Successively segment 3 and
4 are excised after, respectively 15 and 30 minutes separately. In the
meantime, the elective amputation is finished.

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