Foam sclerotherapy is a fast and relatively simple method for ablating pathologic perforating veins. It utilizes a sclerosant, typically sodium tetradecyl sulfate (STS) or polidocanol, to chemically ablate the vein. Tessari et al. describe a technique using a three-way stopcock for mixing and injecting, and this technique has been widely adopted despite lack of approval by the FDA. The technique uses two syringes connected to a stopcock, one with 1 part sclerosant and the other one with 4 parts air. The two syringes are agitated rapidly until a uniform size microbubble is formed [25].

Ultrasound is used to identify the IPV and its associated varicosities. A 25- or 30-gauge needle is typically used for cannulation of the varicosities to allow a larger volume of sclerosant to be injected. Once access is achieved, the foam is created and slowly injected. The foam is echogenic and easily visualized with duplex. Care should be taken to avoid injecting foam into the deep system. This is achieved by applying compression to the junction between the deep vein and IPV using the ultrasound probe. This allows the foam to reflux into the connecting varicosities and ablate the venous plexus. During the injection, the leg is elevated to reduce the amount of sclerosant entering the deep system. After treatment, compression is applied over the treated perforator (Fig. 13.2).

At present, there is no compelling level 1 evidence to support the treatment of IPVs in venous ulcer healing or recurrence [15]. There are a number of small series and retrospective analysis that advocate for IPV ablation in C5 and C6 disease. One of the first studies looking at the efficacy of EVLA in treating IPVs was published in 2010 by Hissink et al. [26]. They prospectively evaluated 58 patients with advance venous disease (C4–C6) that were successfully treated with EVLA with concomitant treatment of refluxing axial veins. They demonstrated that 80% of the ulcers healed with no major complications. Dumantepe et al. demonstrated successful 12-month closure rates approaching 90% with associated improvement in venous clinical severity score [27]. More recently, Zerweck and colleagues reported treatments of 69 IPVs concomitantly with great or small saphenous ablation with a success rate at 30 days of 96% with no reported complications [28]. In 2009, Hingorani et al. published their experience with RFA of IPVs. Their initial success rate was 88% (37 of 43), and they identified venous pulsatility as an independent risk factor for treatment failure in the cohort. Interestingly, the patients with venous pulsatility had only a 20% ablation rate [29].

In one of the larger series, Lawrence et al. enrolled 208 patients with CEAP 6 disease between 2007 and 2010 and looked at the healing of ulcers as an endpoint. All patients enrolled were treated with compression and ablation of axial veins , and after 3 months of aggressive wound care and compression, if the ulcers fail to heal, then perforator incompetence was investigated and treated with endovenous thermal ablation. Forty-five patients in this study met criteria and underwent IPV ablation. Ulcer healing was achieved in 71% at a mean of 193 days. At 13 months, there was a 4% recurrence rate in this cohort. Interestingly, no ulcers healed without the ablation of at least one incompetent perforator [5]. Even though this study is not a randomized prospective study, it does demonstrate the existence of a subgroup of patients with ulcers that will fail to heal even with optimal compression and ablation of refluxing axial veins, and hence may benefit from perforator ablation. Harlander-Locke and colleagues looked to quantify the rate of healing using planimetry software. They demonstrated an improvement in ulcer healing rate following ablation of refluxing axial veins and perforator veins. Technical success in perforator closure was seen in 81.8%, with 76.3% of ulcers healing at a mean of 142 days. Their recurrence was 7.1% at a mean of 12-month follow-up [30]. In 2015, Shi et al. looked retrospectively at a group of 300 patients with incompetent perforator veins associated with different CEAP classes, half of which underwent ablation of the IPVs, and all of which underwent treatment of refluxing axial veins. At 1 year, 81.3% of EVLT-treated IPVs remained closed. At 1 year, 93% ulcers in the EVLT-treated IPV group healed compared to 89.8% ulcers in the untreated IPV group. Although this result is not statistically significant, the group did find that the median ulcer healing time was significantly shortened in the EVLT-treated IPV group from 3.3 to 1.4 months [31]. Masuda et al. identified and treated 80 limbs with incompetent perforator veins with ultrasound-guided sclerotherapy and reported 86.5% of ulcers healed at a mean time of 36 days. Although his ulcer recurrence rate was high at 32% with a mean of 20 months, he was able to demonstrate a statistically significant association between recurrence of ulcer and recurrence of incompetent perforators [32]. A more recent study by Kiguchi et al. showed a 54% thrombosis rate per injection in patients with venous ulceration. The patients that were successfully treated had significant improvement in ulcer healing rates (69 vs. 38% P < 0.001) [33]. There is currently no consensus as to the best modality to ablate IPVs because there are very few comparative studies. In 2016, Hager and colleagues published a comparative analysis between the three modalities in an effort to identify risk factors for treatment failure. They reported the results of 296 ablation procedures in 112 patients, two thirds of which suffered C5–C6 disease . Of the 296 ablations, 21% underwent RFA, 31% underwent EVLA, and the remainder underwent UGFS. They concluded that RFA was the most reliable means of closure, with 73% at 2 weeks. Closure rates were significantly lower for UGFS at 57% but improved to 85% (EVLA) or 90% (RFA) with a subsequent thermal ablation [3].

The complications of treating incompetent perforating veins are modality specific and similar to known ones previously described for the treatment of refluxing axial veins. Common complications such as paresthesia, discoloration, ecchymosis, thrombophlebitis, and pain can be seen in all three modalities [34]. Thermal burns were associated with RFA and EVLA, while TIAs or visual disturbances were more specifically seen with sclerotherapy [15]. Serious complications such as death and pulmonary embolism occur in less than 1%, as demonstrated by a systematic review of 9000 patients undergoing sclerotherapy [35]. In current literature, 1–2% had paresthesia, 1–2% had thrombophlebitis, <1% had skin discoloration, and 1–25% had pain. Although ecchymosis was included by some studies as a complication with an occurrence as high as 70%, most studies did not consider it to be a complication. More rarely were skin necrosis seen in <2% and DVTs seen in 1–5% [3, 26–28, 31, 32, 36, 37].

The treatment of IPVs has been shown to improve venous ulcer healing rates and reduce ulcer recurrence. A proposed algorithm for the treatment of advanced venous disease is depicted in Fig. 13.3. In modern clinical practice, the three modalities most often used are UGFS, RFA, and EVLA. These have been shown to be safe and effective although there are very few studies that compare the techniques. Venous pulsatility has been shown to lead to treatment failure in several studies, as it is typically a surrogate marker for fluid overload and severe venous hypertension [29]. Hager et al. also identified BMI >50 as a predictor of failure among all the modalities; anticoagulation and age were not significant predictors [3]. Future studies will seek to identify other risk factors for treatment failure and attempt to establish an algorithm to best treat IPVs given a patient’s anatomy and comorbidities.