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Summary

Background and objectives

Endovenous treatment is increasingly supplanting open surgery for the treatment of varicose veins. Among emerging endovenous techniques, radiofrequency ablation (RFA) with a ClosureFast catheter is popular in Korea. The objective of this study was to evaluate and compare the efficacy and patient-reported outcomes of RFA of varicose veins.

Methods

This is a retrospective study of a prospectively registered database of patients who underwent RFA for varicose veins from 2012 to 2013 in St. Marys Hospital in Seoul. Korea. Efficient ClosureFast RFA catheters (Medtronic, San Jose, CA, USA) were used. The techniques used for RFA of varicose veins were performed according to the manufacturers recommendations. Duplex scans and venous clinical severity scores (VCSSs) were used to document treatment outcome and patient symptoms before and after the procedures. Treatment outcomes were estimated before the procedure and 3 months, 6 months, and 12 months after the procedure. Outcomes were analyzed by paired t test, chi-square test, or Fishers exact test as well as by logistical regression.

Results

A total of 117 patients were evaluated for 183 consecutive RFA procedures (183 limbs). The initial technical success was 97.3% (178/183). The estimated mean VCSS changed over time from 4.0 ± 1.67 at preprocedure to 0.6 ± 1.05, 0.5 ± 1.02, and 0.6 ± 1.14 at 3 months, 6 months, and 12 months after the procedure, respectively. The improved VCSS was maintained 1 year after the procedure (p < 0.001). Recanalization of the saphenous vein was detected in 20 limbs at the 1-year follow up. The treatment failure group also exhibited a significant decline in the VCSS between preprocedure and 12 months (4.8 ± 1.76 vs. 1.8 ± 2.04, p < 0.001). Specifically, in the treatment failure group, 65% of limbs with episodic recanalization (13/20) were reoccluded or recanalized without venous reflux at the 1-year follow up.

Conclusion

In this study, RFA of varicose veins had an initial success rate of 97.7% and a significantly improved patient VCSS at 1 year. Patients with episodic recanalization of the saphenous vein also exhibited an improved VCSS with favorable duplex findings at 1 year.

Keywords

catheter ablation;minimally invasive surgical procedures;quality of life;radiofrequency catheter ablation;varicose veins

1. Introduction

Varicose veins are one of the most common vascular diseases, and the prevalence of varicose veins in Korea has increased recently.¹ Patients with varicose veins experience symptoms including pain, heaviness, cramping, edema, skin pigmentation, inflammation, and skin ulcers. Endovenous treatments such as scleratherapy, radiofrequency ablation (RFA), and endovenous laser ablation are increasing in popularity for the treatment of varicose veins, owing to their decreased invasiveness and a lower rate of complications.^{2; 3; 4; 5; 6; 7; 8 ;  9} The purpose of this study was to evaluate symptomatic improvement and occlusion rate of saphenous veins after RFA of varicose veins in a Korean patient population.

2. Materials and methods

This was a retrospective review of prospectively registered patients who underwent RFA for varicose veins at St. Marys Hospital in Seoul, Korea, between June 2012 and June 2013. Duplex ultrasound scans were performed before RFA and within 1 week, 6 months, and 1 year after the procedure.^{10 ;  11} Patient symptoms, quality of life, and complications were assessed according to the venous clinical severity score (VCSS) before the procedure and during follow-up visits.^{12 ;  13} The VCSS is a standard scoring system for measuring the severity of chronic venous disease. It can provide serial assessment and evaluate response to treatment. The success of RFA was defined to be complete occlusion of saphenous veins in the follow-up duplex ultrasound scan and the failure of RFA was defined to be recanalization of saphenous veins during the study period.

There are no absolute contraindications to RFA, but RFA of varicose veins was performed if the following inclusion criteria were fulfilled: (1) proper vein size (from 2 mm to 15 mm); (2) no history of deep vein thrombosis; (3) uncorrectable coagulopathy; (4) immobility; and (5) pregnancy.

In this study, we used the ClosureFast RFA catheter (Medtronic, San Jose, CA, USA), which was introduced in 2007 and consists of a 7-cm heating element covered with a lubricious material, an integrated handle, and a cable connected to the VNUS RFG Plus generator (VNUS Medical Technologies, San Jose, CA, USA). The thermal element consists of a coil that is heated by a 460-kHz AC current to a temperature of 120°C during treatment cycles, each having a duration of 20 seconds. A thermocouple on the heating element provided a feedback loop to the generator to adjust the generator output power to achieve and maintain the 120°C temperature.¹⁴

2.1. Procedures

RFA was targeted for the treatment of the great or small saphenous trunk. Under local anesthesia, an ultrasound-guided puncture of the saphenous vein was made around the popliteal area with a 21-gauge needle, and a 7F sheath was introduced into the saphenous vein. Next, a ClosureFast RFA catheter (VNUS Medical Technologies, San Jose, CA, USA) was positioned 2 cm below the saphenofemoral or saphenopopliteal junction. A tumescent injection (100–300 mL of a 500-mL solution of 445 mL of 0.9N saline, 50 mL of 1% lidocaine with 1:100,000 epinephrine, and 5 mL of 8.4% sodium bicarbonate) was then made into the saphenous subcompartment. Sequential heating of the vein was then performed at intervals of 7 cm, heating the vein to 120°C during each 20-second cycle. The first segment was treated twice with the patient in the Trendelenburg position.

Excision of local varicosities was performed after venous access and before insertion of the ClosureFast RFA catheter. After injection of a small amount of 1% lidocaine, a small stab incision was made above the varicose vein. A 2–3-mm stab incision, oriented horizontally at the groin, knee, or ankle or longitudinally along Langers lines elsewhere in the leg, was used to provide access for phlebectomy. The target varicosity was then drawn through the incision, divided, dissected, and avulsed. The skin incisions were small enough that SteriStrip closures (3M, St. Paul, MN, USA) were usually sufficient. However, if any incision was larger than usual, it was closed with a single interrupted absorbable subcuticular suture.

2.2. Statistical analysis

Statistical analysis was performed using SPSS (SPSS 15, IBM, Armonk, NY, USA). Values of p < 0.05 were considered statistically significant. Outcomes were analyzed by a paired t test, chi-square test, or Fishers exact test to compare two groups. The clinical characteristics were summarized. The VCSSs of varicose veins during serial follow ups were compared by paired t test. Risk factors and duplex ultrasound scan results between the successful treatment group and the treatment failure group were analyzed by odds ratio and chi-square test. Logistical regression was used to evaluate the serial outcomes of the procedures.

3. Results

A total of 117 patients with 183 legs affected by varicose veins were enrolled in this study. The mean patient age was 53.2 ± 11.1 years, and the mean body mass index (BMI) was 23.8 ± 2.8. Among the enrolled patients, 65% were women, and 56.4% received treatment for both legs. Eleven patients were smokers or ex-smokers, four had diabetes mellitus, and 21 had hypertension. The mean size of the great saphenous vein (GSV) was 4.93 ± 1.59 mm and that of the small saphenous vein (SSV) 3.51 ± 1.56 mm. Details of the enrolled patients are shown in Table 1.

Table 1. Clinical characteristics of patients with varicose veins treated by radiofrequency ablation.

Variable		Total (n = 117)
Sex	Female	76 (64.9)
	Male	41 (35.0)
Foot	One side	51 (43.5)
	Both sides	66 (56.4)
Vein size	GSV	4.93 ± 1.59
	SSV	3.51 ± 1.56
Age (y)	Mean ± SD	53.2 ± 11.1
	Median (IQR)	55.0 (48.0–59.0)
Height (cm)	Mean ± SD	164.2 ± 8.2
	Median (IQR)	163.0 (159.0–170.0)
Body weight (kg)	Mean ± SD	64.1 ± 10.8
	Median (IQR)	62.0 (56.0–70.0)
Body mass index	Mean ± SD	23.8 ± 2.80
	Median (IQR)	23.4 (21.9–25.4)
Smoking history		9 (7.7)
Current smoker		4 (3.4)
Diabetes mellitus		4 (3.4)
Hypertension		21 (17.9)
Ischemic heart disease		3 (2.56)

GSV = great saphenous vein; IQR = interquartile range; SD = standard deviation; SSV = small saphenous vein.

The symptomatic improvement of varicose veins after RFA is summarized in Table 2. Preoperatively, four patients had severe pain, 26 had severe varicose veins, four had severe venous edema, and three had severe skin pigmentation. After the procedure, no patients had severe pain, varicose veins, venous edema, or skin pigmentation.

Table 2. Venous clinical severity score of patients with varicose veins treated by RFA.

	Preoperative			At 3 mo		At 6 mo		At 12 mo
	Mild	Moderate	Severe	Mild	Moderate	Mild	Moderate	Mild	Moderate
Pain	99 (54.0)	49 (26.7)	4 (2.18)	30 (16.3)	9 (4.9)	18 (14.2)	5 (4.0)	18 (18.1)	2 (2.0)
Varicose vein	45 (24.5)	90 (49.1)	26 (14.2)	30 (16.3)	4 (2.1)	25 (19.8)	—	17 (17.1)	2 (2.0)
Venous edema	55 (30.0)	67 (36.6)	4 (2.2)	20 (10.9)	—	13 (10.3)	2 (1.6)	13 (13.1)	—
Skin pigmentation	14 (7.7)	6 (3.3)	3 (1.6)	5 (2.7)	—	3 (2.4)	—	1 (1.0)	—
Inflammation	—	—	—	—	—	—	—	—	—
Induration	—	—	—	—	—	1 (0.8)	—	—	—
No. of active ulcers	—	—	—	—	—	—	—	—	—
Ulcer duration	—	—	—	—	—	—	—	—	—
Active ulcer size	—	—	—	—	—	—	—	—	—
Compression	—	—	—	—	—	—	—	2 (2.0)	2 (2.0)

RFA = radiofrequency ablation.

The mean preoperative VCSS was 4.08 ± 1.67, which improved to 0.66 ± 1.05, 0.58 ± 1.02, and 0.63 ± 1.14 at 3 months, 6 months, and 12 months after the procedure, respectively (Table 3 ;  Table 4).

Table 3. Comparison of VCSSs during serial follow up.

Total VCSS	Total	Initial	Follow up	p (paired t test)	Correlation
Preoperative versus 3 mo	n = 167	4.16 ± 1.66	0.66 ± 1.05	<0.001	0.174
Preoperative versus 6 mo	n = 126	4.08 ± 1.69	0.58 ± 1.02	<0.001	0.314
Preoperative versus 12 mo	n = 99	4.15 ± 1.66	0.63 ± 1.14	<0.001	0.254

VCSS = venous clinical severity score.

Table 4. VCSSs of patients with varicose veins treated by RFA.

VCSS	Preoperative (n = 183)	At 3 mo (n = 166)	At 6 mo (n = 126)	At 12 mo (n = 99)
Mean ± SD	4.08 ± 1.67	0.66 ± 1.05	0.58 ± 1.02	0.63 ± 1.14
1	13 (7.1)	35 (19.1)	20 (10.9)	23 (12.5)
2	21 (11.4)	15 (8.2)	9 (4.9)	5 (2.7)
3	34 (18.5)	9 (4.9)	8 (4.4)	6 (3.3)
4	38 (20.7)	2 (1.1)	3 (1.6)
5	38 (20.7)	2 (1.1)
6	29 (15.8)
7	5 (2.7)			2 (1.1)
8	5 (2.7)

RFA = radiofrequency ablation; SD = standard deviation; VCSS = venous clinical severity score.

Postoperative serial duplex scans at the 1-year follow-up visit indicated failure of venous occlusion after RFA of the saphenous vein in 15 patients (20 limbs). Specifically, after 1 year, temporal recanalization and complete occlusion were noted in six limbs, recanalization without reflux was noted in seven cases, recanalization with refluxing was noted in four cases, and immediate reoperation without observation was performed in two cases. Three cases were lost to follow up after recanalization (Table 5).

Table 5. Fate of the treatment failure group.

Total		20
Spontaneous reocclusion		6
Recanalization without reflux	Occlusion in 1.5 y	1
	Occlusion in 1.5 y	2
	Persistent recanalization until study endpoint	4
Recanalization with reflux	Observation	2
	Reoperation	2
Follow-up loss		3

With respect to the failure of the occlusion group, the mean age was 56.2 ± 10.4 years, mean BMI 23.5 ± 3.1, mean GSV size 4.83 ± 1.19 mm, mean SSV size 3.59 ± 1.27 mm, mean reflux of the GSV 5.9 ± 2.2, and mean reflux of the SSV 1.0 ± 2.1. In the successful occlusion group, the mean age was 52.8 ± 10.7 years, mean BMI 23.8 ± 2.6, mean GSV size 5.24 ± 1.49, mean SSV size 3.32 ± 1.76, mean reflux of the GSV 4.9 ± 2.5, and mean reflux of the SSV 2.0 ± 3.1 (Table 6 ;  Table 7).

Table 6. Comparison of risk factors between the successful treatment group and the treatment failure group for RFA treatment of varicose veins.

Variables	Success (n = 61)	Failure (n = 20)	Odds ratio (95% CI)	p
Sex (male)	20 (32.7)	7 (35.0)	1.103 (0.381–3.195)	0.855
Age (y)	52.8 ± 10.7	56.2 ± 10.4	1.033 (0.098–1.088)	0.224
Body mass index	23.8 ± 2.6	23.5 ± 3.1	0.966 (0.803–1.163)	0.722
Height (cm)	164.0 ± 7.9	163.6 ± 9.1	0.993 (0.933–1.057)	0.836
Weight (kg)	64.5 ± 11.0	63.4 ± 12.4	0.911 (0.947–1.038)	0.709
History of smoking	4 (6.5)	2 (10.0)	1.583 (0.267–9.371)	0.633
Current smoker	4 (6.5)	1 (5.0)	0.750 (0.078–7.129)	1.000
Ex-smoker	0 (0.0)	1 (5.0)	0.237 (0.160–0.351)	0.247
Diabetes mellitus	3 (4.9)	0 (0.0)	0.743 (0.652–0.847)	0.571
Hypertension	12 (19.6)	3 (15.0)	0.720 (0.181–2.864)	0.751
Heart disease	1 (1.6)	2 (10.0)	6.666 (0.570–77.84)	0.149
No. of diseased limbs			0.829 (0.272–2.526)	0.742
1	16 (26.2)	6 (30.0)
2	45 (73.7)	14 (70.0)
Limb side
Right	31 (50.8)	10 (50.0)	0.967 (0.352–2.657)	0.949
Left	30 (49.1)	10 (50.0)	1.033 (0.376–2.837)	0.949
Preoperative
C1: telangiectases or reticular veins	9 (14.8)	1 (5.0)	0.304 (0.036–2.563)	0.437
C2: varicose veins	47 (77.0)	16 (80.0)	1.191 (0.342–4.148)	1.000
C3: edema	44 (72.1)	16 (80.0)	1.545 (0.451–5.289)	0.486
C4: lipodermatosclerosis and/or atrophie blanche	6 (9.8)	1 (5.0)	0.482 (0.054–4.269)	0.675
C5: healed venous ulcer	—	—	—	—
C6: active venous ulcer	—	—	—	—
Initial VCSS	4.34 ± 1.66	4.8 ± 1.76	1.182 (0.864–1.616)	0.295
Description of initial VCSS
Pain	51 (83.6)	17 (85.0)	1.111 (0.273–4.515)	1.000
Score 1: occasional pain or other discomfort (i.e., not restricting regular daily activity)	24 (39.3)	9 (45.0)
Score 2: daily pain or other discomfort (i.e., interfering with but not preventing regular daily activities)	27 (44.2)	7 (35.0)
Score 3: daily pain or discomfort (i.e., limits most regular daily activities)	0 (0.0)	1 (5.0)
Varicose vein	54 (88.5)	18 (90.0)	1.166 (0.221–6.133)	1.000
Score 1: few: scattered	16 (26.2)	5 (25.0)
Score 2: confined to calf or thigh	29 (47.5)	12 (60.0)
Score 3: involves calf and thigh	9 (14.7)	1 (5.0)
Venous edema	47 (77.0)	17 (85.0)	1.687 (0.431–6.607)	0.542
Score 1: limited to foot and ankle area	17 (27.8)	2 (10.0)
Score 2: extends above ankle but below knee	28 (45.9)	14 (70.0)
Score 3: extends to knee and above	2 (3.2)	1 (5.0)
Skin pigmentation from venous origin	6 (9.8)	3 (15.0)	1.617 (0.365–7.169)	0.682
Score 1: limited to perimalleolar area	5 (8.1)	1 (5.0)
Score 2: diffuse over lower third of calf	1 (1.6)	2 (10.0)
Inflammation	—	—
Induration	—	—
No. of active ulcers	—	—
Ulcer duration	—	—
Active ulcer size	—	—
Compression	—	—

CI = confidence interval; RFA = radiofrequency ablation; VCSS = venous clinical severity score.

Table 7. Comparison of initial duplex scan and procedures between the successful treatment group and the treatment failure group for RFA of varicose veins.

Variables	Success (n = 61)	Failure (n = 20)	Odds ratio (95% CI)	p
Clinical and procedural findings
Reflux of GSV	4.9 ± 2.5	5.9 ± 2.2	1.186 (0.946–1.486)	0.136
Reflux of GSV BK	2.8 ± 3.2	1.2 ± 2.5	0.818 (0.670–0.998)	0.048
Reflux of SSV	2.0 ± 3.1	1.0 ± 2.1	0.860 (0.697–1.063)	0.163
Reflux of CFV	1.4 ± 2.2	1.0 ± 1.0	0.882 (0.662–1.175)	0.227
Reflux of pop vein	0.03 ± 0.21	0 ± 0	—	0.419
Size of GSV	5.24 ± 1.49	4.83 ± 1.19	0.807 (0.552–1.179)	0.269
Size of SSV	3.32 ± 1.76	3.59 ± 1.27	1.096 (0.807–1.490)	0.560
Treatment of GSV	58 (95.0)	18 (90.0)	0.465 (0.072–3.007)	0.593
Treatment of SSV	20 (32.7)	3 (15.0)	0.361 (0.094–1.379)	0.126
Stab avulsion	14 (22.9)	4 (20.0)	0.839 (0.241–2.922)	1.000
Vein access			3.157 (0.188–52.94)	0.435
Micropuncture	60 (98.3)	19 (95.0)
Cut down	1 (1.6)	1 (5.0)
Postoperative complications
Redness	2 (3.2)	0 (0.0)	0.746 (0.656–0.849)	1.000
Petechia	9 (14.7)	1 (5.0)	0.304 (0.036–2.563)	0.437
Hematoma	2 (3.2)	2 (10.0)	3.277 (0.430–24.95)	0.254
Cordlike feeling	3 (4.9)	1 (5.0)	1.017 (0.099–10.37)	1.000
Wound infection	—	—

BK = below knee; CFV = common femoral vein; CI = confidence interval; GSV = great saphenous vein; RFA = radiofrequency ablation; SSV = small saphenous vein.

In the occlusion failure group, the mean total VCSS was 4.8 ± 1.76 preoperatively and 1.8 ± 2.04 at the 1-year follow up. Conversely, in the successful occlusion group, the mean total VCSS was 4.34 ± 1.66 at preoperative status and 1.19 ± 1.37 at the 1-year follow up (p < 0.001, Table 8).

Table 8. Comparison of VCSSs between the successful treatment group and the treatment failure group for RFA of varicose veins.

Total VCSS	Success (n = 61)	Failure (n = 20)	p (unpaired t)
Preoperative VCSS	4.34 ± 1.66	4.8 ± 1.76	0.298
VCSS at 1 y follow up	1.19 ± 1.37	1.8 ± 2.04	0.229
p (paired t)	<0.001	<0.001

RFA = radiofrequency ablation; VCSS = venous clinical severity score.

4. Discussion

The efficacy and safety of endovascular treatment of varicose veins, compared with conventional surgery, have been well demonstrated in a number of studies. Among the available endovascular treatment options, RFA has several advantages, including decreased pain, fewer complications, shorter hospital stay, and faster return to work.^{15; 16 ;  17} In the present study, symptomatic improvement was achieved in all but one patient. The most common symptom was pain (82.8% preoperatively), which was improved to 21.2%, 18.2%, and 20.1% at 3 months, 6 months, and 12 months after the procedure, respectively. In addition, RFA was associated with decreased pain severity. Specifically, moderate to severe pain was present in 53 legs preoperatively compared with nine legs at 3 months, five legs at 6 months, and two legs at 12 months. In addition, there was a statistically significant reduction in other symptoms, including varicose veins, venous edema, and skin pigmentation, after RFA. In general, decreased VCSS was associated with better quality of life.

Follow-up duplex ultrasound scans showed a vein occlusion rate of 97.7% (129/132), 92% (116/126), and 88.8% (89/99) within 1 week, 6 months, and 12 months, respectively. At the 1-year follow up, 20 cases exhibited anatomical occlusion failure according to duplex ultrasound scan. Merchant et al¹⁸ described three types of occlusion failure. Type I consists of permanent failure of occlusion, initially and at follow up, while Type II is initially occluded, but recanalized, and Type III comprises vein trunk occlusion with reflux detected in the groin region. In addition, Merchant et al¹⁸ suggested that BMI and pullback speed during RFA are risk factors for occlusion failure. In this study, we noted two cases of Type I occlusion failure and 16 cases of Type II occlusion failure. Among the 16 Type II cases, three showed reflux, seven showed no reflux, five showed reocclusion, and one was lost to follow up. In addition, between the occlusion failure group and the successful treatment group, there was no significant difference in BMI and pullback speed during the RFA procedure. Interestingly, symptomatic improvement was observed in most patients despite anatomical occlusion failure. Furthermore, only two (10%) of 20 cases in the anatomical occlusion failure group required reoperation. Between the occlusion success group and the occlusion failure group, there was no significant difference in risk factors, clinical characteristics, and improvement of the VCSS. Furthermore, despite occlusion failure, a significant reduction of the saphenous vein diameter and loss of venous reflux were noted, which may explain the symptom improvement. We assumed that endovascular damage causes fibrosis and luminal narrowing; thus, venous reflux can improve, although it failed the occlusion of the saphenous vein in some patients. Lastly, six patients exhibited spontaneous reocclusion after recanalization, which may have been due to reduction of venous size, loss of venous reflux, partial endovascular damage, and flow disturbance.

5. Conclusion

RFA of varicose veins was associated with an obvious improvement in symptoms without severe complications. Over a 1-year follow-up period after RFA of 183 varicose veins, there were 20 cases in which failed complete occlusion of the saphenous vein was noted. Among these 20 cases, 18 exhibited improved VCSSs despite recanalization, while two cases underwent reoperation due to symptom aggravation, which we attributed to the reduction in saphenous vein diameter and loss of venous reflux after the procedure.

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