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Spider veins

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Thread veins commonly occur on the legs. They are also known as spider veins, broken veins, surface veins and venous flares.

Thread veins are generally 1-2 mm in diameter. They are superficial and blue, red or purple in colour.

Treatment options include sclerotherapy and laser treatment:

  • sclerotherapy
    • is a very widely used and cheap technique for treating vessels from 0.5 to 5 mm since early 1900
    • injecting sclerosant agents into the telangiectatic structure using a small 30-gauge needle is considered as the gold standard of leg telangiectasias treatment by many practitioners. In some patients, it is associated with some limitations, including the possibility of hyperpigmentation, telangiectatic matting, and in some cases systemic allergic reactions to the injected sclerosant, post-treatment ulceration, and scarring (1)
      • veins larger than 4 mm can be successfully treated if adequate compression follows injection. Good compression can reduce the risk of developing a symptomatic thrombophlebitis in these larger veins, making sclerotherapy an effective and scarless alternative to stab avulsion
        • during treatment, a sclerosant is injected directly into the vein, causing the irritated vessel lining to swell and seal itself, preventing blood from reentering. The use of foam sclerosing agents has been described as early as 1939 and, since then, many technical improvements have been made
        • the superiority of foam over liquid sclerotherapy has been reported (2)
      • contraindicated to use of sclerotherapy include pregnancy, breastfeeding, allergy to the sclerosant, immobility, significant deep vein incompetence, and thrombophilia
      • complications include skin hyperpigmentation, skin necrosis, phlebitis, transient lymphedema, allergic reaction, transient scotoma, or confusional states (3,4). Cases of DVT have been reported
  • laser therapy
    • endovenous laser therapy
      • defined as the occlusion of a varicose vein using heat energy delivered endoluminally via a lasertipped prob
      • requires the insertion of a probe into the vein to be treated
      • causes nonthrombotic occlusion of a varicose vein via thermal energy provided by a laser. Heat causes fibrosis and scar formation of the targeted vein but the exact mechanism is not known
    • a study revaeled that use of long pulse Nd:YAG 1,064 nm laser can yield results similar to sclerotherapy in the treatment of small leg telangiectasias (1)
    • Nd:YAG (1064 nm) has been shown to be both highly effective and safe for superficial skin VM treatment. In fact, it is considered to be the laser of choice due to its high tissue penetration depth of up to 5-6 mm (5)
    • complications of laser treatment include bruising or ecchymosis in 24-49%, phlebitis in 1-38%, cellulitis in 2.6%, hematoma in 1.3% (6)
      • reported rates of DVT range from 0% to 2.3%
      • an episode of PE has been reported to occur after endovenous laser treatment (7)
      • because the laser causes direct thermal damage to surrounding tissues, rare cutaneous thermal injury complications have been reported


  • 1) Levy JC. Comparison and Sequential Study of Long Pulsed Nd:YAG 1,064 nm Laser and Sclerotherapy in Leg Telangiectasias. Lasers Surg. Med. 2004;34:273–276
  • 2) Yamaki T et al. Comparative study of duplex-guided foam sclerotherapy and duplex-guided liquid sclerotherapy for the treatment of superficil venous insufficiency. Dermatol Surg 2004;30:718-722.
  • 3) Hamel-Desnos C et al Evaluation of the efficacy of polidocanol in the form of foam compared with liquid form in the previous termsclerotherapynext term of the greater saphenous vein: Initial results, Dermatol Surg 2003; 29 :1170-1175.
  • 4) avezzi A. et al. Treatment of varicose veins by sclerotherapy:Two clinical series.Phlebology 2002;17:13-18.
  • 5) Scherer K et al. Nd:YAG lasers (1,064 nm) in the treatment of venous malformations of the face and neck: challenges and benefits, Lasers Med Sci 2007;22 (2): 119-126.
  • 6) Puggioni A et al. Endovenous laser therapy and radiofrequency ablation of the great saphenous vein: Analysis of early efficacy and complications. J Vasc Surg 2005; 42: 488-493
  • 7) Ravi R et al.. Endovenous ablation of incompetent saphenous veins: a large single-center experience. J Endovasc Ther 2006; 2:244-8.
  • 8) Gibson KD, Ferris BL, Pepper D. Endovenous laser treatment of varicose veins. Surg Clin North Am 2007;87:1253-65

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