Predictors of Recanalization for Incompetent Great Saphenous Veins Treated with Cyanoacrylate Glue
In recent years, several promising non-thermal endovenous ablation techniques have been introduced which do not require tumescent anesthesia. These include mechanochemical ablation (ClariVein; Vascular Insights, Quincy, Massachusetts), VariClose (Biolas, Ankara, Turkey), polidocanol endovenous microfoam (Varithena; BTG International, London, United Kingdom), and VenaSeal Closure System (Medtronic, Gorway, United Kingdom). Long-term outcomes following ablation with these non-thermal techniques remains limited compared to the mature evidence base underlying endovenous thermal ablation. This study from Chan et al is a retrospective series of 108 legs in 55 consecutive patients with saphenofemoral junction (SFJ) or great saphenous vein (GSV) incompetence which aimed to identify predictors of great saphenous vein (GSV) recanalization following treatment with VenaSeal. The included patients had Clinical-Etiology-Anatomy-Pathophysiology (CEAP) 3 (60%) or higher disease. Patients underwent VenaSeal with concurrent microphlebectomy and were followed with clinical evaluation and duplex ultrasound at 1-week, 1-month, 6-months, and 24-months post-procedure. VenaSeal was deposited 4 cm distal to the SFJ and at 3-cm intervals along the entire course of the targeted GSV (median treatment length: 28 cm). On follow-up, GSV closure rates were 97% (1 week), 94% (1 month), 89% (6 months), and 76% (12 months). The majority of recanalization occurred at one year and developed from the SFJ rather than segmentally within ablated areas. Cox regression for predictors of GSV recanalization found only GSV diameter ³6.6 mm as a significant predictor (p=0.016). Other evaluated variables, which were not found to be significant, included GSV length, presence of incompetent thigh perforators, clinical severity at presentation, and operator experience. The study also observed low pain and mild ecchymosis following the procedure as well as significant improvements in validated vein symptom scores post-procedure.
Figure 2B. Kaplan-Meier curve showing significantly lower closure rates in GSV ³ 6.6 mm (log-rank test, p=0.002)
The treatment of saphenous vein insufficiency has been revolutionized in the last two decades with the development of endovenous ablation techniques using radiofrequency ablation (RFA) and endovenous laser ablation (EVLA) which offer high rates of technical success at far less morbidity than traditional surgical vein stripping. These techniques; however, do have some disadvantages including the requirement of tumescent anesthesia and ecchymosis and pain during the recovery period. Several new non-thermal endovenous ablation techniques have been developed to address these (and other) limitations of thermal ablation techniques and include cyanoacrylate based compounds (VenaSeal and Variclose), polidocanol foam (Varithena), and mechanochemical ablation (ClariVein). Similar to prior studies, this series demonstrated that VenaSeal has very low associated post-procedural pain which is a benefit over thermal ablation techniques. The prior VeCLose trial for Venaseal demonstrated 99% GSV closure rate at 3-months, but longer term follow-up with VenaSeal is limited. This study demonstrated an increasing rate of GSV recanalization at 12-months follow-up (24% patients from 11% patients at 6 months), highlighting the importance of long-term outcomes data. Notably, the study had substantial drop-off in number of patients who completed duplex follow-up at the later time points, with only 58% patients at 6 months, and 34% patients at 12 months. The authors suggested that the American patient population in the VeClose trial had smaller mean GSV diameters than those seen in the Asian population, but the median GSV diameter in the current study was 6.6 mm, similar to the 6.3 mm mean proximal GSV diameter in VeClose. The Cox regression finding of GSV diameter ³6.6 mm as a significant predictor for GSV recanalization provides useful data for counseling patients who are considering VenaSeal. Prior studies on endovenous thermal ablation techniques have also found larger GSV diameter as significant predictor for recanalization. Insurance reimbursement for VenaSeal remains challenging in many geographic areas and patients may be paying out-of-pocket so management of expectations and advising alternative modalities may be appropriate in patients with larger GSV diameters. The authors mention another series describing the use of larger VenaSeal volumes to achieve durable results in larger caliber GSVs, but definitive long-term outcomes data are lacking. Lastly, all patients in this study wore full-length compression stockings for at least one month post-procedure which is not a universal protocol (one of the marketed benefits of VenaSeal is the lack of need for post-procedure compression stockings) and may therefore affect the generalizability of the results. Non-thermal GSV closure techniques remain an exciting and growing area in the treatment of GSV reflux and more studies like this one are needed to elucidate the optimal technique and algorithm with which to apply these novel modalities.
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Chan YC, Law Y, Cheung GC, Cheng SW. Predictors of Recanalization for Incompetent Great Saphenous Veins Treated with Cyanoacrylate Glue. J Vasc Interv Radiol 2017; 28:665-71.
Jeffrey Forris Beecham Chick, MD, MPH, DABR
Assistant Professor of Vascular and Interventional Radiology
Vice Quality Assurance and Safety Officer
Venous Health Program Faculty
University of Michigan Health System
James X. Chen, MD
Resident in Radiology
Hospital of the University of Pennsylvania