Sclerotherapy Techniques for the Treatment of Varicose Veins

Varicose veins usually develop from reticular veins or larger veins (including the saphenous veins and their tributaries) that reside in or below the subcutaneous fat [12]. The production of an intravascular thrombus produced by sclerotherapy has generally been felt to be a prerequisite for successful varicose vein sclerosis. However, the presence of an intravascular thrombus can serve as an impediment to complete resorption of the vein as a result of subsequent vessel-wall repair and recanalization [3]. Often, it may be more than a year before the recanalized, reconstituted vein can be visibly or palpably discerned [3]. Intravascular thrombosis is minimized utilizing the ultrasound-guided microfoam sclerosing technique, which “pushes” the blood out of the vessel segment, and by applying post-injection-sustained compression to the treated vein. Immediate and sustained compression minimizes the duration required for complete resorption of the vein because adequate compression applied immediately postinjection diminishes the volume of the intraluminal thrombus, even if full-thickness mural destruction has occurred [3]. The goal of varicose vein sclerotherapy, therefore, is transformation of the target vessel into a fibrous chord without the possibility of recanalization.

Varicose vein sclerotherapy requires thorough pretreatment evaluation and planning. Proper patient selection is critical and should include a history and physical examination appropriate for the extent of venous disease and, when indicated, laboratory studies to rule out altered coaguable states [16] (Table 8.10). The patient should also be educated about the procedure, including limitations, alternative treatments, potential adverse side effects, risks, and complications (Table 8.11). Baseline and follow-up photographs are useful to document the clinical extent of disease, location of treatment vessels, any preexisting pigmentation or scarring, and postsclerotherapy outcome and response to treatment. DUS, venous Doppler studies, photoplethysmography (PPR), light-reflection rheography (LRR), air plethysmography, and other diagnostic studies should be reserved for appropriate patients with symptoms of venous disease, large diameter vessels (greater than 4 mm in diameter), or large numbers of telangiectasias indicative of venous hypertension (Table 8.5). The routine use of these expensive modalities in the presence of limited numbers of telangiectasias or vessels less than 1 mm in diameter is discouraged [16].Diagnostic studies may be appropriate in patients with exacerbation or rapid recurrence of their disease process after sclerotherapy.

Table 8.5. Diagnostic evaluation of the venous system of the lower extremity       Preferred method   Pitfalls   Additional methods   Deep veins   Doppler ultrasound   Differentiation SFJ versus CFV SPJ versus popliteal vein   PPG/LRR Venography Duplex   Saphenous trunks   Doppler ultrasound   Differentiation SFJ versus CFV SPJ versus popliteal vein   Percussion Trendelenburg Venography Duplex   Tributaries of saphenous trunks   Doppler ultrasound   N/A   Percussion Duplex   Perforating veins   Clinical exam and Doppler ultrasound   50–80% accurate   Venography Duplex Thermography Fluorescein   Contribution of superficial versus deep reflux   PPG/LRR   N/A   AVP Duplex velocities   Functional evaluation   PPG/LRR   N/A   AVP Foot volumetry   Vulvar varices   Clinical exam for LSV reflux   N/A   Varicography     PPG photoplethysmography, LRR light reflection rheography, SFJ saphenofemoral junction, CFV common femoral vein, SPJ saphenopopliteal junction AVP ambulatory venous pressure, LSV lesser saphenous vein

Table 8.6. Doppler ultrasound versus duplex scanning       Doppler   Duplex   Portability   Portable   Not easily portable “Luggable” units available   Ease of use   Requires short period of training and experience   Requires longer period of training   Cost (approximate)   Unidirectional: $300 Bidirectional: $2,500   Grey scale: $40,000 Color: $150,000 and up   Information obtained   1. Patency, competence of venous valves 2. DVT in thigh (? calf)   Patency, competence of venous valves DVT with greater accuracy Velocity of reflux Anatomy and anomalies of venous system Termination of SSV Thrombosis versus sclerosis   Reliability   Less reliable because of blind, nonpulsed sound beam   More reliable because of actual visualization of vein being examined     DVT deep vein thrombosis, SSV short saphenous vein

Table 8.10. Contraindications to sclerotherapy treatment Absolute Acute superficial or deep vein thrombosis Advanced peripheral arterial occlusive disease (stages 3 or 4) Confinement to bed Hyperthyroidism a Immobility Known allergy to the sclerosant Local infection in the treatment site, or severe generalized infection Pregnancy b Severe systemic disease Relative Allergy to heparin or aspirin Bronchial asthma History of coagulopathies Inability to ambulate Late complications of diabetes Leg edema Marked allergic diathesis Peripheral arterial occlusive disease (stage 2) Poor general health Thrombophilia with history of deep vein thrombosis Use of medications that may affect clotting mechanisms or platelet functions (estrogens, progesterones, etc.)     a Only when sclerosing agent contains iodine b Within the first trimester and after the 36th week of gestation

Table 8.11. Complications and risks of sclerotherapy Allergic reaction, including anaphylaxis Hyperpigmentation Necrosis Nerve damage Orthostatic hypotension Scintillating scotomas Telangiectatic matting Thromboembolism Thrombosis (deep or superficial) pulmonary embolism Thrombophlebitis

There are no uniformly agreed upon techniques or standards available for sclerotherapy of large varicose veins. A common assumption exists that veins larger than 10 mm in diameter are scleroresistant and require surgical removal, especially when associated with saphenofemoral incompetence.However,Kanter has nicely demonstrated that treatment of these largecaliber incompetent veins utilizing ultrasoundguided sclerotherapy (UGS) and 3% sodium tetradecyl sulfate (STS) is possible, with an overall recanalization rate of 10% at 2-year follow- up [7, 8]. Furthermore, Kanter also showed that injection of a 2-ml volume of sclerosant is less effective and is associated with more side effects than a 1-ml volume of sclerosant [8]. Sclerotherapy is generally performed in order of leakage points and from the largest to smallest varicose vein(s), proximal to distal. Recommended concentrations and volumes of sclerosants are listed in Table 8.9. A smooth-moving, disposable or glass 3-cc syringe is required for sclerotherapy, as well as a half- to 1-inch long small diameter cannula or butterfly catheter (23–27 gauge). The various concentrations of the sclerosant used should be carefully labeled on each syringe prior to use. Cotton balls or other padding, and precut tape attached to the side of the surgery tray, should be readily available. Equipment and medications for use in case of allergic reactions should also be on hand. DUS scanning during sclerotherapy allows the phlebologist to precisely locate and treat the pathologic components of the venous system under direct observation and is farsuperior to the handheld Doppler, especially when sclerosing incompetent saphenous junctions, adjacent truncal veins, and perforating veins [15] (Tables 8.5 and 8.6). Although cannulation of the treatment vessel can be performed with the patient standing, injection of the sclerosant is usually performed with the patient in the horizontal position. Areas of reflux are identified with Doppler or duplex scanning and prepped prior to injection.The venous segment to be treated is punctured, preferably during UGS or DUS visualization, so that the intravascular injection can be controlled. When treating saphenofemoral incompetence, the injection site should not be less than 3–4 cm distal to the saphenofemoral junction to prevent injection into the femoral vein [7]. Visualization by DUS scanning ensures that the sclerosant is prevented from actually being deposited at the level of the saphenofemoral junction into the femoral vein [3].However, even if the sclerosant enters the femoral vein, significant mural damage is unlikely because of the rapid dilution associated with the large volume of intravascular blood and the dynamic rate of flow in the vein [3]. Some authors recommend intermittent compression postinjection utilizing the ultrasound transducer [15]. Compression with the probe provides assessment of venous spasm as well as the length of sclerosis of the treated segment. The treatment of large varicose veins requires greater volumes and higher concentrations of sclerosant than smaller ectatic veins [7, 8]. Volumes ranging from 1 to 12 ml per injection site have been recommended. Each milliliter of sclerosant should be injected over an 8- to 15-s period, with 30- to 90-s intervals between injections. Immediate and sustained postinjection compression should be performed. The procedure is repeated proximally to distally along the vessel at approximately 5- to 10-cm intervals for a maximum total volume of 15 ml. A “second look”DUS examination, repeated 1–2 min postinjection, can reveal any persistently patent segment(s) for reinjection, provided the recommended volume of sclerosant has not been exceeded. Immediately postsclerotherapy, class II (30–40 mmHg) or class III (40–50 - mmHg) graduated thigh-high, compression stockings are applied with the patient’s legs elevated approximately 45°, along with focal padding over treated areas. Sustained postsclerotherapy compression may be required for 2–8 weeks or, rarely, longer, with a class II or class III graduated compression garment to be worn while awake. Local compression with padding or foam can be removed as early as the same evening, according to some authors, or several days to weeks later.Currently, there is no general agreement regarding duration or type of compression. I prefer the use of a self-adhesive foam padding manufactured by 3M (Reston self-adhering foam pad) and class II thigh-high graduated compression stockings to be worn for 1 week.Patients should be instructed to walk posttreatment (the recommended length of time currently is not defined). Patients are encouraged to refrain from vigorous activity, as per postoperative sclerotherapy instructions, for treatment of telangiectasias. Follow-up examinations with DUS are recommended at 2 weeks and 6, 12, and 24 months. Thrombus formation, recanalization, persistent reflux, and postsclerotherapy side effects are evaluated and treated, as necessary.