Fate of Vena Saphena Magna Stump After Endovenous Laser Ablation with 980-nm Diode Laser: 12-Month Follow-Up

Abstract

Objective: The aim of this study was to investigate the fate of VSM stump and its relation to the incidence of thrombosis during a-12 mo follow-up. Background Data: Varicose veins are a common problem. There are several treatment alternatives available. Conventional surgical treatment is associated with high recurrence and complications. However, with the recent development of minimal invasive surgery, various techniques have been developed. Endovenous laser ablation (EVLA) is one of these techniques, which has proven to be safe and effective. Since EVLA is safe and has minor adverse reactions, residual VSM stump and its association with thrombosis after EVLA has not been well studied in literature. Materials and Methods: Sixty-nine patients underwent EVLA with a 980-nm diode laser (Ceralas D, Biolitec AG, Jena, Germany), and retrospectively obtained data were analyzed over a 12-mo period. Twenty-six patients were excluded due to the lack of follow-up. All EVLA procedures were performed by the same surgeon, who has experience of EVLA. Laser power was set at 10–15 W depending on the size of targeted vein. The saphenous vein was percutaneously punctured with an 18-gauge needle under ultrasonography guidance. Patients were reassessed at 1 wk, and at 3, 6, and 12 mo after the procedure. Results: Technical success was accomplished in all patients. One patient had flow signals with patent segment of the VSM visualized by venous duplex ultrasonography at 1 mo, which persisted until the 12-mo follow-up. None of the patients developed acute deep-venous thrombosis. Conclusions: The present study shows that residual VSM stump-length measurement differences at 7 d and 12 mo were statistically significant. In future, large-scale studies are needed, focusing on the proper position of the catheter tip to the saphenofemoral junction and timing the intervals of follow-up after EVLA.

Introduction

E ndovenous obliteration methods as treatment options for varicose veins in the lower extremity have been introduced during the last decade. Endovenous laser ablation (EVLA) is the widely accepted and used treatment option, with superior safety and excellent technical success rates for saphenofemoral insufficiency. Short-term benefit with sustained occlusion of the vena saphena magna (VSM) and freedom from reflux at 2 yr has been reported in 95% to 97% of patients.

Since there is no consensus available at the moment, two descriptive mechanisms of action of EVLA have been reported. The first is indirect heating and damage of the vein wall by steam bubble generation, which results in thrombotic occlusion of the vein.^1,2 The second mechanism involves direct heating and damage to the vein wall, resulting in collagen contraction with shrinkage and closure of the vein.³

Saphenofemoral insufficiency is the principal underlying problem, and treatment modalities should involve eliminating this source of reflux with ablation of any associated incompetent venous segments.⁴ Minor complications have been detected after EVLA, including ecchymoses, paresthesia superficial burns, and thrombophlebitis. Major complications such as deep-vein thrombosis (DVT) after EVLA can be seen in 0% to 7.7% of cases in the literature.^4
–6 The association between VSM stump and venous thrombosis after EVLA has not been well studied.

In our study, we planned to investigate the fate of VSM stump during a 12-mo follow-up period, and its possible close proximity with thrombosis.

Materials and Methods

From February 2008 to February 2009, 69 patients (40 female, 29 male) underwent EVLA with a 980-nm diode laser (Ceralas D, Biolitec AG, Jena, Germany), and retrospectively obtained data were analyzed. A total of 26 patients were excluded due to the lack of follow-up. The patients' demographic data are summarized in Table 1.

Table 1.

Patients' Demographic Data

Age (mean)	42.22 ± 9.65
Gender (M/F)	29/40
Family history of varicose vein (%)	66.66
CEAP classification (n%)	CEAP – class 2	16 (23.18%)
	CEAP – class 3	24 (34.78%)
	CEAP – class 4	28 (40.57%)
	CEAP – class 5	1 (1.44%)
	CEAP – class 6	0 (0%)
Preoperative VCSS (mean)	8.91 ± 2.39

Study inclusion criteria included varicose veins causing saphenofemoral junction (SFJ) incompetence with VSM reflux, as demonstrated by venous duplex ultrasonography. Exclusion criteria included extremely tortuous and elongated VSM that would not permit vein catheterization on preoperative venous duplex ultrasonography examination, non-palpable pedal pulses, inability to ambulate, history of or recent DVT, pregnancy, or nursing.

All EVLA procedures were performed by same the surgeon, who has experience of EVLA. To establish uniformity, preoperative, operative, and postoperative venous duplex ultrasonography assessments were done by the same radiologist. As described by Labropoulos et al., reverse flow on venous duplex ultrasonography of more than 0.5 s on the Valsalva maneuver is considered and used as evidence of reflux.⁷

All statistical calculations were conducted using the SPSS software package (V9.01; SPSS Inc., Chicago, IL).

The study protocol was approved by our local ethic committee, and all patients gave written informed consent before treatment.

Technique

Because of the hospital feasibility and policy, all the procedures were done in the operating theater. Procedures were performed under local or general anesthesia depending on patient and surgeon preference. Patients were placed in the prone position and in a reverse Trendelenberg position to distend the veins. The leg was prepared and draped in a similar way to conventional surgery. Under duplex ultrasonography guidance through a sterile ultrasonography probe cover (Philips, EnVizor, Bothell, WA), the great saphenous vein was visualized at the most distal knee level. The saphenous vein was percutaneously punctured with an 18-gauge needle under ultrasonography guidance when the vein could be grossly identified. A 0.035-inch J-tip guidewire was threaded through the needle, toward the SFJ. A 5F introducer sheath was passed under ultrasonography guidance up to the SFJ over the J-tip guidewire. Then, the guidewire was replaced by a 600-μm forward-looking flat-tip optical fiber connected to a 980-nm diode laser and located about 25 to 30 mm distal to the SFJ. The tip of the fiberoptic catheter position was confirmed by ultrasonography and by visualization of the red aiming beam of the laser through the skin. Fiberoptic catheter tip positioning was done on purpose to prevent possible cloth formation (preventing propagation of DVT). The distance between the entry point at the knee or below and the SFJ was measured and recorded.

Tumescent anesthesia was used in all cases. Tumescent anesthetic solution was prepared from 500 mL of physiological saline, 5 mL adrenaline (1:100.000), 5 mL of 8.4% sodium bicarbonate, and 35 mL of 1% lidocaine. It was stored in refrigerator at 4°C until use. For anesthetic solution injection, a Klein pump with 22-gauge spinal needle was used into the fascial plane surrounding the vein at intervals along its course under ultrasonography guidance.

Laser energy was always delivered endovenously in a pulsed fashion with 10 mm/5 s pullback speed during the procedure. This cycle was repeated until a distance of 2 cm to the puncture site of the VSM was reached. Before activation of the laser, individuals in the operating theater wore protective laser goggles, and unauthorized admissions were not allowed during the laser procedure. After reducing the blood volume inside the veins by placing the legs in the Trendelenburg position, leg-elevation laser energy was fired. Energy delivery began at 2–3 cm below the SFJ, confirmed by ultrasonography to exclude and protect the deep-vein system. In all cases, the fiberoptic laser tip was positioned to preserve the inferior epigastric vein. In the meantime, manual compression was applied over the treating segment to enhance the vein-wall apposition around the laser tip during the procedure. Laser power was set at 10–15 W depending on the size of the targeted vein. The ablation procedure continued until a distance of 2 cm to the puncture site at the skin was reached. Following laser ablation from the groin to the knee, the laser was deactivated before the fiber was withdrawn from the skin. The ultrasonography guidance was used during all the steps. Patients were discharged with elastic compression bandages 48 h after the procedure. The patients were asked to wear class II (30–40 mmHg) full-thigh graduated compression stockings during the daytime for 6 wk, except when sleeping or showering. Patients were also asked to ambulate and to resume their normal activities without heavy workouts, which could cause venous pressure elevation. All patients received the non-steroid anti-inflammatory orally bid for 3 d. Low molecular heparin prophylaxis was not used routinely. Intraoperative mean measurements of data are shown in Table 2.

Table 2.

Intraoperative Mean Measurements of Data

Preoperative VSM diameter (mm)^*	6.14 ± 1.49
EVLA – treated vein segment (cm)	29.78 ± 6.49
EVLA – energy (LEED^**) (J/cm)	66.86 ± 6.22
Distance between fiberoptic tip and saphenofemoral junction (mm)	28.61 ± 2.69
EVLA procedure duration (min)	59.00 ± 18.30
Tumescent anesthesia volume (mL)	401.81 ± 49.87

2 cm below the saphenofemoral junction.

Linear Endovenous Energy Density.

Patient follow-up examinations

Patients were reassessed at 1 wk, and at 3, 6, and 12 mo at a cardiovascular surgery outpatient center. Each follow-up assessment included venous duplex ultrasonography, and functional and physical examination. Venous duplex ultrasonography, which was done by the surgeon briefly and followed by the radiologist in more detail, was used to establish DVT, to confirm ablation of VSM, and to measure the length of the VSM stump. The VSM stump length was defined and measured as a distance between the SFJ and the occluded VSM on venous duplex ultrasonography. The definition of acute DVT was the extension of the thrombus. VSM recanalization was considered positive if any part of the treated VSM segment showed a flow signals pattern during the Valsalva maneuver.

The patients were asked about their symptomatic relief and were checked for any adverse effects, such as bruising, paresthesia, pain, and DVT, during the assessments.

Results

In this study, all surgical and radiological procedures were performed by the same surgeon and radiologist to maintain study group uniformity. The EVLA procedure was technically successful in the study group. Immediately after EVLA, successful occlusion was noted in all patients.

One patient had flow signals with patent segment of the VSM visualized by venous duplex ultrasonography at 1 mo. It persisted and showed at the 3-, 6-, and 12-mo follow-ups. There was no evidence of acute DVT or clinically documented pulmonary emboli during the follow-up period for this patient. Ultrasonographic-measured SFJ length for this patient before EVLA was 8.2 mm and the VSM diameter at the distal knee level was 6.7 mm.

One patient had an open segment of VSM at the 3-mo follow-up. This did not persist at the 6- and 12-mo follow-ups. We accepted this patient as having complete occlusion with successful treatment. As with the other patient, there was no evidence of acute DVT or clinically documented pulmonary emboli during the follow-up period.

The residual VSM stump length measurements from the follow-ups are summarized in Table 3.

Table 3.

The Residual VSM Stump Length Measurements During Follow-Ups

Length of the VSM stump (mm)	Results (mean)	Standard deviation
At 7 d	17.52	8.12427
At 3 mo	15.50	7.89019
At 6 mo	11.75	6.50065
At 12 mo	10.29	10.55046

After statistical analysis, we found that the difference at day 7 and 12 mo were statistically meaningful with a 95% confidence interval (upper: 5.72871; lower: 9.30159). Post EVLA measurements of the VSM stump length at day 7, and 3, 6, and 12 mo are reported in Fig. 1.

FIG. 1.

Post EVLA mean measurements of VSM stump length at day 7, and at 3, 6, and 12 mo follow-up.

In our study group, patients were encouraged to walk immediately (90 to 120 minutes after the procedure) and use compression stockings for six weeks as for DVT prophylaxis.

Discussion

There are several studies showing that EVLA is a safe and effective treatment for VSM insufficiency. The exact mechanism of EVLA remains subject to controversy, and the fate of VSM after EVLA are unclear. Min et al. describe this process as the swelling of the injured vein wall obliterating the lumen; and other authors describe the thrombotic process associated with an increase in the level of circulating d-dimer.^1,4 This controversial difference can be explained with differences in laser wavelength used and the amount of laser energy applied, since there is no standard protocol available for EVLA.

The inconsistency in the amount of blood within the vein during laser fire can possibly cause nidus formation for thrombosis and propagation to the deep-vein system. Since we routinely used the Trendelenburg position, leg elevation, manual compression, and large-volume tumescent anesthesia, there was no evidence of acute DVT and associated problems such as pulmonary emboli reported in our patients.

The definition of DVT after EVLA is described as an extension of the thrombus from the SFJ into the common femoral vein. Because of the close proximity with the EVLA procedure, the distance of the fiberoptic catheter tip from the SFJ probably plays a major role in the development of DVT. The classic VSM stripping technique requires careful surgical technique to avoid a cul-de-sac providing a nidus for thrombus propagation. Flush ligation for classic VSM stripping cannot be easily accomplished for EVLA, since most techniques recommend leaving the upper 1–2 cm of the VSM open to avoid occlusion of the groin collaterals and to maintain patency of the SFJ. In our study group, the mean distance between the fiberoptic catheter tip and the SFJ measured 28.61 ± 2.69 mm. Since this result is similar to previous reports, there are also some variations on the ideal distance of the catheter tip. Reported articles have measured this distance to be between 5 and 30 mm.^4,5,8

Recently, Pleister et al. addressed the importance of positioning the fiberoptic laser catheter tip to maintain the patency of the inferior epigastric vein for establishing wash-out flow.⁸ EVLA is not analogous to classical high ligation, which interrupts all saphenofemoral tributaries while leaving a patent VSM. EVLA, on the other hand, obliterates the VSM and typically leaves the superficial abdominal and pudendal drainage relatively undisturbed, with unimpeded physiological venous flow from these areas into the common femoral vein providing wash-out flow.

Puggioni et al. suggested that excessive and repetitive manipulation of intravenous equipments (fiberoptic catheter or guidewire) could be the reason for the development of vein thrombosis.⁵ Because of the possibility of endothelial damage, excessive manipulation of the catheter and guidewire should be avoided.

As reported in the literature, duplex scanning is not only the gold standard for assessing superficial venous insufficiency, it has also been valuable guidance for treatment and follow-ups of EVLA. Due to variations in the literature and as a new center for EVLA, we designed the post-procedure follow-up at 1 wk, and at 3, 6 and 12 mo.⁶ However, there is no agreement regarding how frequent post EVLA follow-up should be.

Ultrasound imaging identified suitably superficial veins of adequate diameter for fiberoptic catheter introduction. The use of ultrasonography facilitated a less traumatic puncture and avoided vasospasm, vein dissection, and ruled out excessive tortuosity in the target segment, which would otherwise have compromised the procedure. Successful EVLA required precise positioning of the fiberoptic catheter tip at the end of the saphenous vein, as close as possible to the SFJ, to ensure VSM obliteration without leaving a terminal patent stump. It was always possible to visualize the catheter for optimal SFJ positioning, and femoral vein injury from catheter protrusion into the deep vein was avoided.⁹

Conclusion

As described previously, EVLA is safe and effective treatment, but there is no consensus available on some topics. In the future, we may need more large-scale studies focused on the proper position of the catheter tip to the SFJ, timing the intervals of follow-up after EVLA. Standardized and randomized controlled studies with an extended follow-up time will be very helpful to identify these issues.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

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