Mechanochemical ablation for symptomatic great saphenous vein reflux: A two-year follow-up

Introduction

As highly successful minimally invasive techniques have transformed the treatment of varicose veins, more emphasis is being placed on secondary outcome measures such as periprocedural and postoperative pain, a quicker return to normal activities, and quality of life.^1–4

Endovenous thermal procedures require the use of tumescent anesthesia, which increases procedural discomfort. Although ultrasound-guided foam sclerotherapy is an alternative which does not need tumescent anesthesia, it requires multiple treatments and often has inferior results compared to other treatment modalities.^5–9 To minimize the negative aspects of both endothermal ablation and ultrasound guided sclerotherapy, the ClariVein device (ClariVein, Madison, CT, USA) was introduced. This device utilizes mechanochemical ablation (MOCA) techniques for the treatment of saphenous vein incompetence.^1,10,11 Current studies in the literature come from small studies from single institutions with short-term follow-up ranging from six weeks to 24 months. The goal of this multicenter study was to evaluate the efficacy of MOCA in the treatment of the great saphenous vein (GSV) at two years.

Methods

The design and treatment protocol have been previously described. ⁵ In brief, this was an observational study during which data were prospectively collected from six vein centers using an electronic database. Demographic information, clinical data, procedural details, pain levels, and postoperative complications were noted. Patients were followed with physical examination and duplex ultrasound at one week, 3, 6, 12, and 24 months. The Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification was used to grade the chronic venous disease severity, and the venous clinical severity score (VCSS) was used for the presence and intensity of the symptoms at baseline and follow-up.^12,13

Patients with CEAP Class 2 or higher and symptomatic GSV reflux involving the sapheno-femoral junction (SFJ) were included and followed prospectively. Retrograde flow in the GSV > 0.5 s was considered abnormal. ¹⁴ Only veins > 4 mm and < 12 mm in diameter measured at 2 cm below the SFJ were included. Measurements were performed in the standing position. Patients with previous ipsilateral venous interventions, small saphenous and accessory vein reflux, nonsaphenous vein reflux, acute deep or superficial vein thrombosis, deep vein obstruction, or those with significant peripheral arterial disease or limb infection were excluded. All patients had conservative therapy with gradient elastic compression stockings prior to their procedure. Procedures were performed in the outpatient office setting.

MOCA of saphenous veins has been described in detail using the ClariVein device. ¹ Local anesthesia was instilled and GSV access obtained with a micro-puncture kit under ultrasound guidance. The ClariVein catheter was advanced through a micro-puncture sheath followed by the dispersion wire (angle tipped, rotating 360° at 3500 r/min) positioned 2 cm below the SFJ. The drive unit of the device was subsequently initiated to cause vein spasm and sclerosant (polidocanol or sodium tetradecyl sulfate) was infused. The type of sclerosant was up to the discretion of each physician, and up to 12 ml of 1.5% polidocanol or 1.5% sodium tetradecyl sulfate was used. The total volume amount was determined by the diameter of the GSV near the SFJ. The pullback rate was between 1.0 and 2.0 mm/s. Procedural details from each institution were recorded.

Statistical analysis

Descriptive statistics were used to analyze patients’ demographics and clinical characteristics. Data were progressively censored as patients became lost to follow-up. Univariable Kaplan–Meier survival curve analysis was used to calculate success rates after MOCA. The time to failure was the difference between the date of MOCA and date that recanalization of the GSV was noted. Changes in CEAP and VCSS were compared with Wilcoxon signed-rank test. Statistical significance set at P value of < .05. SPSS 20 (SPSS Inc., Chicago, IL, USA) was used.

Results

A total of 126 patients were initially enrolled. Demographics and procedural details have been previously reported. ⁹ Follow-up was available for 79 patients at 12 months and 65 patients at 24 months. Of these 65 patients, 70% were female with a mean age of 70 ± 14 years and an average BMI of 30.5 ± 6. The mean diameter of the GSV in the upper thigh was 7.6 mm, and the mean treatment length was 39 cm. Sodium tetradecyl sulfate was used in 84% of patients and polidocanol in 16% during MOCA. Adjunctive treatment of the varicosities was performed in 14% of patients (phlebectomies 9% and sclerotherapy 5%). Comparing demographics and procedural details between the original group of patients and those seen at two years, there was no significant difference.

Closure rates were 100% at one week, 98% at three months, 95% at 12 months, and 92% at 24 months. There was one patient with complete recanalization of the GSV with reflux, and four patients with partial recanalization ranging from 7 to 12 cm (mean 9 cm). In patients with partial recanalization, two had no reflux and two had reflux. During follow-up, six patients underwent ultrasound-guided sclerotherapy for symptomatic varicosities. This resulted in a success rate at 24 months by life table analysis of 89%, 95% CI 82.2–95.8% (Figure 1). When compared to preoperative values, the VCSS improved from 9.5 to 3.0 (Figure 2). The CEAP class similarly decreased (Figure 3). At 24 months, 63% had no residual varicose veins, and 83% were asymptomatic with overall significant improvement in CEAP and VCSS (P < .001) for all time intervals. No major complications such as nerve damage, deep vein thrombosis, or infection were observed. Thrombophlebitis was found in 10%, ecchymosis in 9%, while one patient developed hematoma at the access site, all of which were managed conservatively and resolved without requiring further treatment. OPEN IN VIEWER

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Figure 2.

Median VCSS at baseline and during follow-up.

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Figure 3.

Median CEAP class at baseline and during follow-up.

Discussion

This is the first analysis describing two-year MOCA outcomes in patients with symptomatic GSV reflux. Given the significantly improved clinical scores at two years and a GSV closure rate of 92%, MOCA is a highly effective method of treating GSV incompetence. Minimally invasive techniques have changed the way saphenous vein insufficiency is treated. With long-term closure rates reported at >90%, fewer complications, minimal scars, and quicker recovery times, endovenous thermal procedures are now used in daily practice.^4,7,9 However, these techniques still have moderately high rates of pain, discomfort, and risk of skin and nerve damage. ³ As such, the focus is shifting to methods that are more tolerable while maintaining effective treatment.

MOCA employs a hybrid technique that induces both mechanical and chemical damage of the venous endothelium. Histologically, there is a complete disappearance of the endothelium with subsequent vein fibrosis.^5,15,16 Early feasibility and safety studies had GSV closure rates of 87% at six weeks, ¹¹ and initial human clinical trials had six-month closure rates of 97% with minor complications. ¹ Longer follow-up studies of 12 months by Van Eekeren et al. ⁴ and a smaller one of 24 months by Elias et al. ² maintained high closure rates of 88 and 97%, respectively. The closure rate of 94% at six months, 95% at 12 months, and 92% at two years in the current study is comparable to previous reports. Although we had one complete and four partial recanalizations which can also be seen in endothermal techniques, our success rate remained >90% at two years. Micro-phlebectomies and foam sclerotherapy were used at the time of procedure or subsequently in 23 patients that had larger varices. However, many of the patients did not have any adjunct procedure as they were older and came for symptomatic relief rather than cosmesis. Even with an older population, larger vein diameter, higher C class, and higher BMI, our results are comparable to those of other endovenous modalities.^7,8

Pain during the procedure and postoperatively as well as quality of life were significantly improved with MOCA compared to traditional endovenous techniques.^3,6,17 Bootun et al. ⁶ performed a randomized controlled trial comparing MOCA to radiofrequency ablation (RFA) in 60 patients, looking at intraprocedural pain levels. There was a significantly lower maximum pain score with MOCA (19.3 mm) compared to RFA (34.5 mm) on a 0–100 mm visual analog scale (P < .001). The average pain score was also significantly lower (MOCA 13.4 mm versus RFA 24.4 mm, P = .001). Clinical improvement and quality of life scores were improved with MOCA. Similarly, Van Eekeren et al. ³ compared MOCA to RFA in a prospective observation study of 68 patients, evaluating postoperative pain levels. MOCA was associated with significantly less pain in the immediate 14-day postoperative period as compared to RFA on a 0–100 mm visual analog scale (4.8 mm versus 18.6 mm, P < .001). This correlated with earlier return to work and normal activities, and subsequently overall improved quality of life scores. We found that these improved secondary outcomes with MOCA also remain after initial therapy. There was a marked reduction in the CEAP class and the VCSS over time. In both figures a continuous improvement up to two years is shown. However, we believe that this occurred up to six months. One possible explanation is that the 35 patients who were lost to follow-up at that interval had worse CEAP scores and so their absence creates a more favorable CEAP and VCSS. Few ulcer patients also healed after three months. Another explanation may be that adjunctive therapies at follow-up in some patients allowed further improvement. In most prospective studies there is no continuous improvement after three months unless further procedures are being done. Typically the patients at two years remain at the same level or get somewhat worse.

MOCA has also been successful in patients with small saphenous vein reflux. Twelve-month follow-up of 50 patients treated for small saphenous vein incompetence had a closure rate of 94% and minimal complications. ¹⁸ Additionally, a small study in six patients with persistent ulcers found improved ulcer healing rates after MOCA of the below knee GSV. ¹⁹ Published data and the current report demonstrate that the MOCA procedure is very effective in treating a wide array of patients with venous insufficiency.

This report does have its limitations. There was no control group and previously reported data from other studies were used for comparison. We did not look at disease-specific quality of life scores, although previous studies have demonstrated improvement.^3,6 A significant number of patients were lost to follow-up and this may weaken the data reported at two years. More than an attempt was done to bring these patients back but it was not successful. Most likely the vast majority of these patients had a very good clinical outcome as they had similar clinical presentation and patterns of reflux with those that did have follow-up.

Conclusion

Given the periprocedural advantages and the sustained closure rates of >90% at two years, MOCA is a very good treatment option for GSV incompetence.