Endovenous Thermal Ablation of Saphenous and Perforating Veins

Historical Background

Venous valve anatomy was first described in the 1500s, but with the exception of compression wraps, treatment for chronic venous disease (CVD) was not considered until several centuries later. Trendelenburg described saphenous vein ligation in 1891 as a treatment of varicose veins, but it was soon recognized to be associated with a high recurrence rate. Ligation and stripping of the entire saphenous vein became a mainstay of therapy in the twentieth century, but this method was later modified to selective stripping of the upper portion of the great saphenous vein to reduce of the risk of neuralgia observed with vein stripping below the knee.

Sclerotherapy, or chemical ablation of the saphenous vein, was described over the past 2 centuries, but the safety profile of ablative chemical agents was not considered acceptable until the 1960s. The application of ultrasound guidance proved to be a useful adjunct, but the success rates of chemical ablation remained suboptimal with a high risk of recanalization. In the late 1990s endovenous thermal ablation was first described using radiofrequency (RF) energy, and soon thereafter endovenous laser treatment was developed.

Indications

The types and stages of CVDs have been defined by a classification system composed of four components: clinical stage (1-6), etiology (primary, secondary, or congenital), anatomy (deep, superficial, or perforator system), and pathophysiology (reflux, obstruction, or both), known by the acronym CEAP ( Fig. 60-1 ). Another scoring system that has gained popularity is the venous clinical severity score, which assigns a score to various clinical attributes, such as pain, varicose veins, edema, skin changes, use of compression, and ulceration. Such scoring systems can be helpful in evaluating outcomes and disease progression.

Varicose veins may be associated with distinct pattern of clinical findings, categorized into six clinical stages (C1-C6) in the CEAP classification system. Early symptoms (C1) are mild and include aching, tiredness, heaviness, or throbbing while upright without overt varicosities. Conservative measures such as support hose at 20 to 30 or 30 to 40 mm Hg of external compression often alleviate early symptoms. As the degree of venous hypertension increases, enlarging varicosities can cause local discomfort. Pain, cramping, or restless leg symptoms at night, as well as itching, can be associated with venous disease. Numbness or sharp or radiating pain are not usually attributable to venous insufficiency. Varicose veins (C2) are often associated with one or multiple sources of reflux and may be symptomatic, progressive, or of cosmetic concern. Although edema (C3) may result from CVD, other causes, including lymphedema, lipedema, medication effects, pulmonary, cardiac, renal, hepatic, endocrine, or sleep apnea, should be excluded. Venous stasis skin changes (C4) in the gaiter distribution, including pigmentation, eczema, lipodermatosclerosis, inflammation, and ulceration, are associated with multiple sources of reflux with or without obstruction. Skin changes are an indication for treatment of superficial venous reflux, if present. Skin ulceration (C5-C6) requires compression and local wound care, which should precede treatment of CVD. Surgical stripping of the great saphenous vein has decreased ulcer recurrence, but multiple sources of reflux, including superficial, perforator veins, and deep venous reflux, may be present.

Treatment should always begin with conservative measures, including compression therapy, exercise, weight loss, and intermittent elevation. Continued signs or symptoms of progressive venous insufficiency consistent with CEAP C2 to C6 venous disease are indications for endovenous or surgical treatment. A history of superficial vein thrombosis (SVT) does not preclude endovenous treatment. Both thermal and chemical ablation techniques can be used to treat recanalized refluxing veins after SVT.

Absolute contraindications to endovenous thermal ablation of saphenous and perforating veins include an inability to ambulate, the presence of arteriovenous malformation or uncompensated deep venous obstruction with poorly developed collaterals, pregnancy, and allergic reaction local anesthetic. Relative contraindications include the presence of superficial veins that lie within 1 cm of the skin, because a risk of skin burn exists. This can be prevented by injecting tumescent anesthesia to increase the depth of the vein to greater than 1 cm from the skin. If the vein is immediately subdermal, alternatives to thermal ablation should be considered given the risk of a phlebitic reaction, prolonged pain, and skin changes with retraction or pigmentation. Likewise, tortuous veins may increase the difficulty of advancing the catheter. Aneurysmal vein segments or larger vein diameters (>25 mm), as well as short refluxing vein segments (<3 cm long) and veins with small diameters (<3 mm) may be best treated with other approaches.

Preoperative Preparation

• Ultrasound evaluation. Duplex evaluation of the superficial venous system should be performed in the upright position ( Fig. 60-2 ). All major leg veins should be evaluated in B mode for compressibility, wall thickness, and the presence of internal echoes. Axial veins should be described with regard to diameters, depths, length within the fascia, degree of tortuosity, and communications with perforators or other enlarged tributaries. Perforators are assessed for diameter at the fascia level, location, and the presence of reflux with the patient seated and dangling the leg. Augmentation of venous flow with distal compression cuffs or manual squeeze of the calf are used with color flow Doppler waveform analysis of each refluxing vein.

  

• Preoperative vein assessment. The target vein is mapped by ultrasound and marked, and diameters and depths are measured. Major tributaries; large refluxing perforators; tortuous, partially occluded, and aneurysmal segments; and refluxing duplicate veins should be noted using a marker pen. Entry sites are selected where the vein is superficial, but ablation is halted proximal to the entry point to prevent skin burn or phlebitis. Preprocedure photographs are helpful for documentation ( Fig. 60-3 ).

  

• Assessment of thrombotic risk. Evaluation of personal or family history of thrombosis should be conducted, and those at increased risk of thrombosis should be assessed for an inherited thrombophilia. Endovenous ablation can be performed while on warfarin, and low-molecular-weight heparin can be administered perioperatively to those patients at increased risk.

• Medications and compression. An oral benzodiazepine and an antibiotic are prescribed 1 and 2 hours before the procedure, respectively. If indicated, low-molecular-weight heparin is also administered 1 to 2 hours before the procedure. A 30 to 40 mm Hg thigh-high stocking with an open toe and a waist attachment should be available and applied immediately after the procedure.

Pitfalls and Danger Points

• Bruising and hematoma

• Superficial phlebitis

• Deep vein thrombosis

• Thrombus extension to deep vein junction

• Thermal skin injury

• Paresthesia

• Recanalization

• Neovascularization

Endovascular Strategy

Great Saphenous Veins

The great saphenous vein begins anterior to the medial malleolus of the ankle, travels up the medial thigh, and terminates at the saphenofemoral junction (SFJ) at or below the inguinal ligament and medial to the femoral artery ( Fig. 60-4 ). Anterior and posterior accessory saphenous veins may be present and may be a source of concurrent or recurrent varicosities after treatment of the great saphenous vein.