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Interventional Treatment Options for Small Saphenous Varicose Veins
Introduction
Varicose veins are common, and affect nearly a third of adults in Western societies. Although women present more frequently for treatment, Lee et al observed a significantly higher age-adjusted prevalence of varicose veins in men (40% vs. 32% in women).1 Patients present with a variety of symptoms that they attribute to their varicose veins, including pain, heaviness, burning, itching, superficial thrombophlebitis, skin changes, and cosmetic issues. Bradbury et al found that even in the presence of truncal varices, most lower limb symptoms probably have a nonvenous etiology.2 Venous ulceration is known to be related to venous incompetence,3,4 and Gohel et al have shown that while superficial venous surgery does not improve the healing rate of venous ulcers, it does reduce the risk of recurrence.5 Despite the lack of supporting evidence regarding symptomatology, many patients request intervention for their varicose veins, and upwards of 50,000 interventional procedures are undertaken each year in the United Kingdom (UK). The vast majority of procedures are for great saphenous varicose veins (GSV). The surgical treatment of small saphenous vein (SSV) incompetence is regarded by most vascular surgeons as more challenging and as a higher risk than GSV surgery. The aim of this article is to examine the different interventional options for small saphenous varicose veins.
Why Does SSV Management Pose a Challenge?
The anatomy of the saphenofemoral junction is relatively constant, whereas that of the saphenopopliteal junction (SPJ) is highly variable.6–9 The SSV terminates at the SPJ, which is usually located in the popliteal fossa at the level of the knee crease. However, invasive and non-invasive investigations have revealed great variation in the location of the SPJ in relation to the knee crease; 49% of SPJ are at least 2 cm from the knee crease, and up to 13% may be more than 10 cm above or below.9 There is also significant variation in the presence and location of the Giacomini vein.6 Locating the SPJ at operation can be far from straightforward. There is also concern regarding the risk of nerve damage during the SPJ dissection and SSV stripping.10 Both the common peroneal and tibial nerves may lie close to the SPJ and be encountered during the exposure. The sural nerve often lies in close proximity to the SSV in the lower third of the calf, although this may be variable.11 The role of pre-procedural duplex ultrasonography to identify the level of the SPJ has been widely debated. De Maeseneer et al found duplex to be reliable in demonstrating the location of the SPJ location to within 1 cm.12 Yet, the routine use of pre-operative duplex to mark the site of the SPJ has not always improved the operative outcome. In 2002, Rashid et al reported that in 59 patients who underwent pre-operative duplex marking, the SPJ remained intact and incompetent 6 weeks later in 14% of procedures.13 Kambal et al reported that diagnostic duplex imaging and subsequent marking with the hand-held Doppler accurately located the SPJ in 88% of patients and obviated the need for a second pre-operative duplex.14 While there has been considerable research into the treatment of both primary and recurrent GSV, few studies have looked specifically at SSV. There is limited evidence on which clinicians can base their clinical practice. Furthermore, in recent years, there has been an explosion in the development of interventional techniques for varicose veins, and the options now include: endovenous laser ablation (EVLA), radiofrequency ablation (RFA), and foam sclerotherapy, in addition to standard surgery.
Surgical Management
The traditional surgical approach to the treatment of saphenopopliteal junction incompetence is open flush ligation of the SSV at the SPJ. The access is usually obtained via a transverse incision in the popliteal fossa at the site of the SPJ, which is marked preoperatively. A survey of UK vascular surgeons in 2004 found great variation in open surgical techniques for SSV procedures, with respect to pre-operative assessment, marking and surgical technique.15 Of those surveyed, the majority (89%) requested diagnostic duplex imaging for SSV, but only 50% requested pre-operative duplex marking of the SPJ. At operation, approximately three quarters of surgeons followed the SSV into the popliteal fossa and divided it as close to the SPJ as possible, though only 10% formally exposed the junction with the popliteal vein. A total of 55% surgeons removed a segment of proximal SSV, whereas 15% formally stripped the SSV routinely.15 A study in 1996 examined the cause in 70 legs with recurrence following SSV surgery using duplex imaging. In 61% of cases, the SSV was found to be the main source of reflux in the popliteal fossa; an incompetent gastrocnemius vein accounted for 34%.16 O’Hare et al conducted a multicenter observational study of the outcome after primary SSV surgery at nine UK hospitals, and among 219 patients. The incidence of recurrent varicose veins was not reduced in patients who had undergone SSV stripping. After one year, stripping the SSV (compared to simple ligation) did, however, reduce the rate of recurrent SPJ incompetence significantly (13% vs. 32%).17
Endovenous Treatments
Endovenous treatments fall into two main categories: foam sclerotherapy and endoluminal thermal ablation.
Foam Sclerotherapy
Sclerotherapy is an old and well-established treatment for varicose veins.18 The technique fell into disrepute when surgery was found to be superior for the treatment of truncal venous incompetence.19 Sclerotherapy has had a resurgence in popularity in the last decade following a description of foam sclerotherapy.20 For truncal varices, most practitioners inject foam sclerosant into the vein under ultrasound guidance. However, many continue to use liquid sclerosant for smaller reticular veins.
The technique of foam sclerotherapy varies with respect to the chemical employed (polidocanol, sodium tetradecyl sulphate), the gas mixture (air, carbon dioxide), the syringes (glass or plastic), sclerosant:gas ratio (1:3, 1:4), and the use of a filter. The sclerosant foam is commonly produced using the two-syringe Tessari technique.21 In the UK postal survey, 69% of surgeons who responded used sodium tetradecyl sulphate.22 A meta-analysis by Tisi revealed that choice of sclerosant, dose, formulation, and the type of post-treatment compression had very little effect on the outcome.23
Although the long-term results are not yet known, foam sclerotherapy has become popular since it can be performed as an ambulant treatment under local anesthetic in the office, and can therefore be offered to a wide range of patients, including those unfit for general anesthesia. The technique is applicable to both great saphenous and SSV, but seems particularly suited to those with recurrent veins for whom surgery is more challenging and potentially more complicated.
Varicosities in the SSV also fall into this higher risk category for surgery and seem ideal for foam sclerotherapy. Clinical series of foam sclerotherapy treatment have been reported with maximum follow up of 3 years, with rates of successful occlusion of 74–93%.24,25 O’Hare et al reported mid-term results for complicated and uncomplicated varicose veins and found a complete truncal occlusion rate of 74% at 6 months.24 Clinicians who perform routine duplex follow up, with reinjection of any patent veins, have described superior occlusion rates of 81% at 3 years.26 Similarly, Coleridge-Smith et al reported 88% GSV and 83% SSV occlusion after a mean follow up of 11 months.27 A multicenter, European, randomized control study found that while surgery was slightly more effective than foam sclerotherapy at 12 months (80.4% vs. 78.9% truncal occlusion), foam was less painful and resulted in a faster return to normal activity.28
Reported side effects of foam sclerotherapy include severe thrombophlebitis or brown staining in the skin in up to 5% of patients.27 More worrying is the visual disturbance that is seen after about 2% of procedures, and the risk of deep vein thrombosis (DVT).29 A study of patients undergoing routine duplex imaging within one month of foam sclerotherapy identified a 1.9% DVT rate, although 4 were asymptomatic.29
A number of authors have described rare focal neurological events that may be related to the air bubbles contained within the foam. In the UK, the National Institute for Health and Clinical Excellence (NICE) is investigating the technique, but is currently recommending it as safe to use, with arrangements for local audit and governance.30
Foam sclerotherapy could be a valuable option for treatment for the SSV, since it avoids surgery to the popliteal fossa with its associated risks. This may be even more significant when considering the case of recurrent SSV, where surgery can be extremely difficult. The SSV is relatively straightforward to cannulate, and a number of small series suggest that foam treatment is effective, at least in the short term, although longer follow up is awaited.31 The potential need for repeat injections in the event of recurrence does not appear to disturb patients or practitioners.
Endothermal Ablation
Endothermal ablation techniques involve the cannulation of the truncal vein under ultrasound guidance and the insertion of a catheter/fiber into the vein. The catheter/fiber is connected to an energy source of either laser or a radiofrequency generator. The heat generated by the energy source is then applied to the endoluminal surface of the vein and the vein is obliterated as the fiber/catheter is withdrawn. Both procedures can be performed as ambulant therapy using tumescent local anesthesia. A mixture of local anesthetic and saline solution is injected around the vein within the fascia. This is thought to act as a heat sink and reduce thermal injury to the surrounding tissues,32 as well as compressing the vein and increasing the efficacy of the procedure. Both RFA and EVLT have been approved by NICE.33,34
Endovenous Laser Ablation
Endovenous laser ablation (EVLA) techniques vary in the use of laser wavelengths from 808 nm to 1320 nm. The use of longer wavelengths does not appear to alter occlusion rates but may be associated with less pain, and bruising.35 Another area of variability is the laser dose which can range from 20–95 J/cm. Lower doses are associated with higher rates of recanalization, but higher doses with increased pain, paresthesia, and even burns. Darwood et al advocate a minimum dose of 60 J/cm.36 A randomized clinical trial compared the outcomes of EVLA and surgery for the treatment of primary GSV. After 3 months, the results were found to be comparable, but patients returned earlier to work after EVLA.37 These findings have been supported by Proebstle, who reported a 97% occlusion rate at 28 days, and Min, who described less than 7% recurrence at 2 years.38,39
EVLA is a technique particularly applicable to the SSV, since it is easy to canulate in the calf. The SSV should be punctured above its lower third to avoid damage to the sural nerve, which may be closely applied.40 The outcome of EVLA treatment to the SSV has been investigated by Nwaejike, who undertook EVLA for 66 primary and six recurrent SSV. There were no periprocedural complications or nerve injuries, and at a median follow up of 14 months there were no varicose vein recurrences.40 Gibson et al investigated 187 patients with SSV incompetence. One week after SSV EVLA, 6% of patients had a sliver of thrombus protruding into the popliteal vein on duplex imaging. Nine patients required anticoagulation; none progressed to DVT or pulmonary embolus (PE).41 Of 120 patients who attended for final follow up at 11 months, 96% still had an occluded SSV. Similarly, Kontothanassis described complete occlusion of the SSV in 228 (98.7%) of patients two months after EVLA. Recanalization was seen in 1 patient after 12 months, and 2 after 24 months. The reported rate of paresthesia was 2.25%.42
The main complications of EVLA include bruising (11–100%),43,44 phlebitis (3–30%)45 and nerve injury (1–10%).34 Burns, DVT, and PE are rarely reported,39 and there are occasional reports of cutaneous pigmentation.43,46
Endovenous Radiofrequency Ablation
Endovenous radiofrequency ablation (RFA) has recently become very popular following the development of new technology that provides faster energy delivery. Earlier RFA technology employed a continous pullback system (VNUSClosure, VNUS Medical Technologies, Inc., San Jose, California), which failed to gain widespread popularity due to the long procedure time. The new technologies (VNUS ClosureFast, VNUS Medical Technologies, Inc., or Celon, Olympus Medical) are much quicker, delivering segmental ablation with energy delivery to 7 cm vein segments in 20 seconds, or continous pullback at a speed of 1cm/sec. However, much of the published work refers to the original system. Merchant et al reported occlusion rates of 87% after 5 years in a multicenter, prospective registry. Only 4% of their study group had SSV and therefore, results for this group were not analyzed separately.47 However, the rate of paresthesia was reported after RFA for SSV: 8.9% at 1 week and 9.5% at 6 months. The authors reported that attention to technical aspects such as careful tumescent anesthesia infilltration, catheter placement in the SSV, and patient monitoring reduced the rate of paresthesia to 0.3% in one center.47
A meta-analysis of RFA for primary GSV included 8 eligible studies (randomized trials, non-randomized prospective trials, retrospective trials) reported between 1994 and 2007. A total of 428 patients underwent either RFA (52%) or surgery (48%) as primary treatment. The authors concluded that RFA procedures were at least as effective as surgery in eliminating GSV reflux, with similar complication rates.48 In a multicenter, randomized, controlled trial (EVOLVeS), Lurie et al compared the results of RFA and surgery for GSV. Patients who had RFA had quicker return to normal activity and improved quality of life after four months. However, after 2-year follow up, both groups had a similar clinical outcome: 33% patients after RFA and 28% after surgery had no signs of venous disease (clinical CEAP score = 0).49 Four patients in the surgery group developed neovascularization in the groin, compared to one after RFA. Others have reported similar occlusion rates of 90% at 2 years50 and 75% at 3 years51 for the GSV. Complications observed are similar to those seen after EVLA. Thermal injury occurs in 0–7%, but this rate is reduced with tumescent infiltration.50,52 Paresthesia is reported in 0–15% and seen more commonly in the treatment of the lower leg, phlebitis is seen after 2%, and DVT or PE, 1%.47,53
Although reports do not specifically refer to the SSV for the same reasons as EVLA, RFA is indicated for patients with SSV. It should be noted that recent guidelines from VNUS recommend that the patient should remain awake during treatment, and that the distal third of the SSV should be avoided, due to proximity of the sural nerve.54 Recurrent varicose veins. Varicose vein surgery is associated with a high incidence of recurrence. Recurrent varices after surgery (REVAS) have been defined by international consensus as the presence of varicose veins in a leg previously treated surgically for varices with or without complimentary therapies.55 Recurrence rates can be as high as 40% five years after surgery.56 In a study by Perrin et al, the saphenofemoral junction was identified as the primary site of recurrence after 48% of GSV procedures. Technical failure and growth of new vessels (neovascularization) appear to be equally responsible in many series.57
A number of different methods have been investigated to produce mechanical inhibition of angiogenesis at the SFJ, including pectineal fascia and polytetrafluoroethylene (PFTE) patch closure.58–60 Many venous specialists believe that the endothermal treatments (and sclerotherapy) may prove to reduce the risk of neovascularisation due to the lack of surgical stimulus, and because the endothelium is ablated and not exposed. This remains unproven, but if correct, it will clearly apply to both the SPJ and SFJ.
Compared to GSV surgery, there is very limited literature regarding recurrence after interventions for SSV. van Rij identified a recurrence rate at the SPJ of 25% at 3 weeks, increasing to 52% after 3 years. At 5 years, 13/25 limbs had reflux in the popliteal fossa due to a new venous connection.59 Perrin has categorized the causes of recurrent varices in the popliteal fossa into 4 groups: inadequate pre-operative assessment, inadequate surgery, neovascularization, and progression of the disease. Perrin goes on to recommend that ultrasound-guided foam sclerotherapy should be the treatment of choice for recurrent SSV unless duplex imaging shows an incompetent SPJ stump with a gross reflux filling the venous network.55 The assumption is that the causes of recurrence are similar for both GSV and SSV, and therefore, the limitations of surgery on the rate of recurrence pertain to both.
Conclusion
Despite the large volume of scientific research into GSV, outcomes after intervention for SSV remain underreported. Modern comparative studies have reported similar early clinical outcomes after surgery, RFA and EVLA for the treatment of venous reflux.49,61,62 Yet most describe an early advantage in terms of reduced pain and earlier return to normal activity for the endovenous methods.
Standard surgery for SSV does seem to vary quite considerably, and the significant recurrence rate might be improved by attention to detail and routine stripping of the SSV. Contrary to previous belief, stripping does not seem to pose a significant risk of nerve damage. Indeed, the proximity of the sural nerve to the SSV may mean it is more at risk after endothermal ablation, although the danger may be obviated by tumescence. Foam sclerotherapy appears to offer a simpler technical option for the treatment of the SSV, but, as yet, there remains an absence of specific data regarding the late outcome.
The fundamental change that has occurred in the last decade is the move to treat varicose veins away from the operating theater under general anesthesia, towards ambulant, office-based management. This has had cost advantages, freed up expensive theater time, and has improved the convalescent phase for patients. All the above interventions have been shown to improve quality of life after the treatment for varicose veins. Comparison of medium and long-term outcomes with the new methods will determine which become routine. In the meantime, surgery remains the standard against which the new methods should be tested. The one thing that the new methods require is an extension of the skills normally required by the vascular specialist. The use of ultrasound imaging to guide interventions and percutaneous catheterization techniques formerly belonged solely to the skill set of the radiologist. Vascular specialists should ensure that they have learned the basic skills before embarking on new endovenous technologies. In the UK, recommendations for training and credentialing are emerging.63 The management of venous disease in the next 10 years is likely to continue to evolve rapidly. In the meanwhile, venous specialists should be offering a choice of therapy to patients with varicose veins.
Manuscript submitted May 22, 2009, provisional acceptance given June 12, 2009, accepted June 23, 2009.
Address for correspondence: Mr. J.J. Earnshaw, Gloucestershire Royal Hospital, Great Western Road, Gloucester GL1 3NN. E-mail: jjearnshaw@tiscali.co.uk.
Disclosure: The authors disclose no conflicts of interest regarding the content herein.
