Sclerotherapy




Historical Background


Sclerotherapy is the chemical ablation of abnormal veins. The modern goal of therapy is an irreversible fibrotic occlusion, followed by reabsorption of the target vessel. Sclerotherapy is an old technique revolutionized by recent technological advances. Elsholz performed the first known endovenous treatment when he used a chicken bone needle and pigeon bladder syringe in 1665 to treat venous ulcers. Pravaz invented the syringe in 1831, and Rynd invented the hypodermic needle in 1845. Sclerotherapy’s popularity has increased and decreased sporadically over the last 200 years. A randomized, controlled trial in the 1970s showed sclerotherapy to be less durable than surgery. Sclerotherapy was then revolutionized by the advent of foamed sclerosants and ultrasound guidance, which have greatly improved efficacy and decreased risk. Foaming detergent sclerosants improved sclerosant potency and allowed sclerosant visualization by ultrasound. Ultrasound guidance allowed better anatomic visualization, greater hemodynamic understanding, more precise foam targeting and delivery, and monitoring for unwanted foam passage into deep veins. With these advances, sclerotherapy has now become an appropriate treatment for any type or size of vein.


The development of sclerotherapy has been limited by the range in techniques. This practice variation has produced inconsistent results that make generalizations about the procedure difficult. In the last few years, however, variations in technique have begun to be evaluated and the resulting knowledge has improved overall results. There have been two European consensus meetings on foam sclerotherapy, in 2003 and 2006, which arrived at a consensus opinion from a panel of those experienced in sclerotherapy.




Preoperative Preparation





  • History and physical examination. Symptoms and signs of chronic vein disease include varicose veins, telangiectasias, extremity pain or swelling worsened with standing and improved by elevation, and skin changes around the ankle area.



  • Duplex ultrasound. The duplex ultrasound examination permits determination of venous anatomy and hemodynamics. Superficial, perforator, and deep venous systems are examined for obstruction or reflux. Venous reflux is retrograde blood flow of over 0.5 seconds.



  • Magnetic resonance angiography. Patients with evidence of a vascular malformation, such as lesions present since birth, or abnormal anatomy or blood flow on ultrasound, should have further testing, usually magnetic resonance angiography, to determine whether the malformation is high flow or low flow. Such malformations should be treated by a multidisciplinary team, often containing experts in phlebology, vascular surgery, plastic surgery, dermatology, and orthopedic surgery. Low-flow venous malformations can often be treated successfully by foam sclerotherapy.



  • Sequence of treatment of chronic venous disease. Abnormal veins are usually treated beginning with the superficial system, followed by the perforator veins and finally the deep system. Superficial vein therapies have good efficacy and minimal side effects. Perforator vein treatments are technically efficacious but of uncertain patient benefit in many cases. Deep vein treatments carry a higher risk, have more variable success rates, and are usually treated only in patients with particularly severe symptoms and only at a specialized center.



  • Sequence of treatment of superficial venous disease. Superficial veins are usually treated in the following order when symptomatic reflux is present: saphenous veins, tributary veins, and localized veins. Sclerotherapy can be used to treat almost any abnormal vein. It is most effective for veins less than 6 to 7 mm in diameter, but is still effective with excellent technique at almost any vein diameter. Endovenous thermal ablation and surgical ligation and stripping are performed more often than sclerotherapy in the United States for symptomatic incompetent saphenous veins. Ambulatory phlebectomy is an alternative for tributary veins or localized varicosities, especially at larger vein diameters. Surface laser therapy can be used for telangiectasias and reticular varicosities, but sclerotherapy is considered first-line therapy for these veins on the lower extremity.



  • Preoperative patient counseling. In a recent randomized, controlled trial, polidocanol microfoam proved noninferior to surgical treatment for saphenous vein reflux. In a recent metaanalysis, ultrasound-determined pooled saphenous ablation rates at 3 years were 77% for sclerotherapy, 78% for stripping, 84% for radiofrequency ablation, and 94% for laser ablation. Sclerofoam injection improved ulcer healing rates in patients with severe chronic venous insufficiency in one study. Sclerotherapy success rates around 80% have been reported for tributary veins, perforator veins, and recurrent varicose veins after surgery. Sclerotherapy produces minimal procedural and postprocedural pain. It is easier to perform than most alternative strategies. However, even with recently improved techniques, the need for repeat treatment is high. Therefore it is important to inform patients that retreatment may be required.





Pitfalls and Danger Points





  • Deep vein thrombosis (DVT) and thrombophilia. Active DVT or obstruction is a contraindication to sclerotherapy, because abnormal superficial flow is often required to bypass the obstruction. Risks and benefits in patients with increased risk of DVT, such as patients with thrombophilia, cancer, or limited mobility, should be carefully weighed. Screening for thrombophilia should be considered in patients with prior unprovoked or multiple episodes of thrombosis. Prophylactic anticoagulation should be considered for these more complicated patients if treatment is necessary. A typical prophylactic regimen is enoxaparin 40 mg subcutaneous just before sclerotherapy and then daily thereafter for 7 days.



  • Symptomatic patent foramen ovale. Foam sclerotherapy should be avoided in patients with symptomatic patent foramen ovale, because these patients may be at increased risk of neurologic complications because of passage of foam through a right to left shunt. Symptoms associated with patent foramen ovale include stroke or transient ischemic attack of undefined etiology and migraine or migrainelike headaches. Patients with other known but asymptomatic right to left shunts may have a greater risk of neurologic complications. Sclerofoam injection may precipitate a migraine headache, and patients with this history should be warned of the risk.



  • Allergic reaction. Allergy to a sclerosant may necessitate avoiding the agent. Having multiple allergies is a relative contraindication to sclerotherapy. Anaphylaxis after sclerotherapy is a rare complication, but physicians should be equipped for and prepared to manage such an emergency.



  • Pregnancy. The safety of sclerotherapy during pregnancy has not been established. In addition, varicosities appearing during pregnancy often decrease in size or resolve spontaneously. Treatment is usually delayed until around 3 months postpartum if possible.



  • Arterial insufficiency. Sclerotherapy is less successful in patients in whom external compression is difficult to apply, such as patients with arterial insufficiency or severe obesity.





Endovascular Strategy


Sequence of Treatment of Superficial Veins


Veins are first treated at the proximal source of reflux and then closed distally until ablation is complete. This strategy allows the interruption of proximal sources of pressure, which plays a major role in the pathophysiology of chronic venous disease. Abnormal proximal vein pressure because of reflux is relayed distally through the venous system in refluxing veins when the patient’s extremity is below heart level because of the increased blood volume and the weight of the blood column from gravity. Ambulatory venous hypertension, the inability to reduce venous pressure through calf muscle contraction and venous valve closure, is the major cause of symptoms of chronic venous disease.


Selection of a Sclerosant Solution


Sodium tetradecyl sulfate (STS) is the most frequently used sclerosant in the United States because of good efficacy, low risk of side effects, and its approval by the U.S. Food and Drug Administration as a liquid sclerosant. Polidocanol is another detergent sclerosant used often in Europe. By using varying concentrations and foaming techniques, STS can be used in almost any type of vein. Liquid sclerosant is most often used to correct reticular varicosities and telangiectasias, whereas foam is most often used for all sizes of varicose veins. Table 62-1 is a general guideline for recommended STS concentrations. Emerging evidence, however, indicates that higher sclerosant concentrations may not always be more effective than lower concentrations, as had been previously assumed.


Mar 13, 2019 | Posted by in VASCULAR SURGERY | Comments Off on Sclerotherapy
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