Endovenous ablation has become the treatment of choice for chronic venous disease (CVD) and chronic venous insufficiency (CVI). There are many different types of modalities to treat CVI, including thermal energy commonly with endovenous laser ablation (EVLA), radiofrequency ablation (RFA; ClosureFast, Medtronic), and less commonly with steam and cryotherapy. In addition, nonthermal ablations are effective in venous ablation and include ultrasound-guided foam sclerotherapy (USGFS), mechanical occlusive chemical ablation or mechanochemical ablation (MOCA; ClariVein, Vascular Insights, ClariVein South Jordan UT), cyanoacrylate glue (CAG; Sapheon, VenaSeal, Medtronic, VenaSeal Minneapolis MN), and liquid sclerotherapy. Physician compounded foam is also used in the treatment of truncal varicose veins and tributaries, as well as recurrent varicose veins. Recently, proprietary polidocanol endovenous microfoam (PEM; Varithena, BTG International Ltd., Varithena St. Paul MN) ablation has been brought to the market in the United States, following several studies evaluating safety and efficacy and a randomized controlled trial evaluating the effectiveness in the treatment of the great saphenous vein and its tributaries. Although both thermal and nonthermal techniques cause less pain and allow earlier return to activity and work compared with surgery, there are known complications that are both unique and common and will be the subject of this chapter.
Thermal Ablations: Endovenous Laser Therapy and Radiofrequency Ablation
A review of the English-language literature determined that the complications attributed to EVLA are pain, bruising, superficial burns, nerve injury, arteriovenous fistulae, deep venous thrombosis, and endothermal heat-induced thrombosis (EHIT). A large review of the world literature encompassing 12 countries, including Europe, United Kingdom, South and Central America, and the United States, reported on the top six major complications, with ecchymosis and paresthesia most commonly seen ( Table 38.1 ). There is wide variation in reporting ecchymosis, because of the lack of reporting standards. Pain is usually assessed with a visual analog scale during and immediately after the procedure and at 1 to 2 week follow-up, and pain is usually higher with EVLA at lower wavelengths (810, 940, 980, and 1064 nm, target hemoglobin), while EVLA at higher wavelengths (1320 nm and 1470 nm, target water) have reported both less pain and ecchymosis. A randomized trial of EVLA (980 nm) and RFA demonstrated significantly less pain at 3 and 10 days, with significantly lower levels of analgesic tablets required, with patients treated with RFA. However, in a recent large meta-analysis comparing EVLA and RFA, pain was similar in both treatment groups following the procedure. The International Endovenous Laser Working Group (IEWG), a multicenter registry utilizing 810- and 980-nm diode laser, evaluated complications after treating more than 1000 limbs. Overall complications were 3.3% and there were no cases of motor nerve damage and no pulmonary embolisms (Pes). There was one case of third-degree skin burn (0.1%), six cases of deep venous thrombosis (DVT, 0.6%) (five at the saphenofemoral junction [SFJ] and saphenopopliteal junction [SPJ] 0.5%, and one in a gastrocnemius vein), and 27 cases of sensory nerve involvement (2.7%). Burns from EVLA are a rare complication. This occurs from heat generated close to the skin when trying to treat epifascial veins or veins close to the skin ( Fig. 38.1A,B ), with a risk of full thickness burn. Multinational registries documented skin burn rates between 0.14% and 1.32% with EVLA. Utilizing adequate tumescent anesthetic and not treating veins close to the skin is an important method of avoiding burns. Specific recommendations to avoid skin burns would include adequate tumescence that encircles the GSV on ultrasound, almost forming a “halo”, which usually requires 300–500 ml of tumescent anesthetic in the GSV segment treated. In addition, caution should be applied when attempting EVLA of epifascial veins, or using higher wavelength EVLA or nonthermal techniques. With thermal ablations, nerve injuries can most commonly occur to the great saphenous vein (GSV, especially below the knee) and to the sural nerve when treating an incompetent small saphenous vein (SSV, especially in the distal calf) ( Fig. 38.2 ) and are directly related to proximity of the nerve and vein. Injury leads to cutaneous paresthesia, which is usually transient but may last up to 6 months before resolving. The peroneal nerve, which is a motor and sensory nerve, is located posterior to the fibula head and in close proximity to the SPJ. Injury occurs by heat transfer, and recommendations to avoid nerve injury include careful needle entry under ultrasound guidance, large volume of tumescence (150–300 ml), and avoidance or judicious use of ablation in areas at high risk of nerve injury, specifically keeping a distance of at least 2–3 cm from the SPJ to avoid injury to the tibial nerve and not using thermal ablation below the tendinous insertion of the gastrocnemius muscle, where the sural nerve is in very close proximity to the SSV. These principles also apply to treating the GSV with either EVLA or RFA. A very rare complication after thermal ablation is arteriovenous fistula (AVF, about 11 reported in the literature). AVF usually occurs during administration of tumescent anesthetic and/or thermal injury, the majority are asymptomatic, and AVF can lead to GSV recanalization. Conservative treatment is usually offered, but if the patient is symptomatic with high output cardiac failure, repair will be necessary. Reducing the risk of this rare complication can be accomplished by instilling a large volume of tumescent anesthetic liquid (300–500 ml), proper ultrasound guidance, and injecting tumescent anesthetic /ablation 2–3 cm distal to the SFJ.
|Complication||Ecchymosis||Paresthesia||Phlebitis||Burns||Deep venous thrombosis||Pulmonary embolism|
EHIT is defined as propagated thrombus in the deep system. There are four stages (I: confined to the SFJ; II: extending in less than 50% of the deep venous system; III: extending in more than 50% of the deep venous system; IV: total occlusion of the deep vein). From the reported literature, venous thromboembolism (VTE) from thermal ablations ranges between 0% and 5.7%, but generally is less than 1%. Two large studies evaluated the experience of EHIT in both EVLA and RFA. In 2470 patients treated with RFA (n=2120) or EVLA (n=350), the incidence of EHIT II–IV was 0.28%. In another large experience of 3083 patients treated with EVLA (n=3009) or RFA (n=74), EHIT II occurred in 1.9% of EVLA, and in 2.6% of RFA (P=0.31). Procedural attention to optimal visualization of the SFJ and increasing the distance to 2.5–3.0 cm from the SFJ to the tip of the device will reduce the event rate of EHIT. There are yet no current standards or guidelines for treating EHIT, but the consensus is that cases of EHIT II should either have follow-up evaluation and/or low molecular weight heparin (LMWH) for 2 weeks, and that cases of EHIT III–IV are treated with 3 months of anticoagulation.
RFA is also a thermal ablation and has a good safety profile. Major complications include skin pigmentation, wound problems, paresthesia, and phlebitis ( Table 38.2 ). Several large reviews have studied the rate of all EHIT following RFA. In one large series of 2470 limbs, the rate of EHIT was 0.4% and in another smaller series of 252 limbs the rate EHIT was 0%. There are several skin complications worth mentioning since they are seen with thermal and nonthermal ablations, as well as surgery, and are derived from multimodality randomized controlled trials (RCT; Table 38.3 ). The most common are thrombophlebitis, skin staining, hyperpigmentation, and skin lumpiness, of which the latter two are greatest with foam.