Sclerotherapy for Varicose Veins: When Injections Are the Right Choice
Yes, many varicose veins can be closed with injections, though not all of them. Sclerotherapy suits varicose branches, reticular veins, veins that return after earlier treatment, and branches still visible after a main vein has been closed. A leaking main trunk is usually closed first by ablation, which UK guidance places ahead of injection.
The injection is only as good as the vein it is used on. For how the medicine seals smaller veins, see how sclerotherapy works; for the service itself, see sclerotherapy in Dubai.
Why a Leaking Trunk Is Usually Ablated First
Most varicose veins are branches of a main surface vein, the great or small saphenous vein, whose valves have failed. A standing duplex ultrasound scan shows whether that trunk leaks and where the branches join it.
For a leaking trunk, NICE guideline CG168 recommends endothermal ablation first, ultrasound-guided foam sclerotherapy if ablation is unsuitable, and surgery if foam is unsuitable. Dr. Sohrabi's practice follows that guidance: he closes leaking trunk veins by ablation and uses sclerotherapy for the veins it suits. Injection is one part of the full range of varicose veins treatment, not a default.
Which Varicose Veins Suit Injection
Varicose branches. For branches that cause symptoms, the 2023 Society for Vascular Surgery guideline recommends removing them through tiny incisions or closing them with ultrasound-guided foam.
Branches left after trunk ablation. NICE advises considering treatment of leaking branches at the same time as the trunk, and the same US guideline recommends one sitting, keeping a later, staged session for anatomical or medical reasons. Branches still visible afterwards can be injected.
Reticular veins. The flat blue-green veins in the skin, which often feed spider veins, respond to liquid or foam, as the US guideline recommends for those that cause symptoms.
Residual and recurrent veins. According to the same guideline, ultrasound-guided foam is now the most common treatment for varicose veins that return after earlier treatment, because it avoids operating again through scar tissue.
Injection is not always the most lasting choice for a branch. In a Dutch randomised trial of 98 legs, varicose veins had returned within a year in 12 of 48 legs after compression sclerotherapy, against 1 of 48 after removal through tiny incisions, though removal caused more blisters, scarring, bruising and matting. Removal is more reliable for lasting clearance; injection avoids incisions and is easy to repeat.
Liquid or Foam, and the Medicines Used
The medicine is a sclerosant, most often polidocanol or sodium tetradecyl sulphate. For varicose veins it is usually given as foam: mixed with air between two syringes, it pushes blood aside rather than diluting into it, so it stays against the vein wall for longer. Published standards of care regard foam as the more reliable form for larger veins. Liquid remains the usual choice for smaller reticular veins.
What a Session and Recovery Involve
Each vein is found on ultrasound and a fine needle or small cannula is placed in it. The foam is injected while the screen shows it filling the vein, and several veins can be treated in one sitting. There is no incision. According to the NHS, you go home the same day and should be able to return to most usual activities straight away.
Dr. Sohrabi advises compression stockings for one to two weeks afterwards. Cleveland Clinic notes that larger injected veins may feel lumpy or hard for several months. A vein that has not fully closed can be injected again at a later session.
How Long the Results Last
The trunk data explain why ablation comes first. In a Finnish randomised trial of 196 patients, the great saphenous vein was still closed at five years in 96 per cent after surgery, 89 per cent after laser ablation and 51 per cent after foam. A 2017 meta-analysis of trials with at least five years of follow-up put anatomical success at 34 per cent for foam and 83 to 88 per cent for surgery and laser.
A reopened trunk is not the same as a visible varicose vein, though. In a Danish trial of 500 patients, visible veins had returned at five years in 32 per cent of legs after foam, 39 per cent after laser, 35 per cent after stripping and 19 per cent after radiofrequency ablation. Further treatment was needed in 38 per cent of foam-treated legs and 17 to 23 per cent of the others.
Risks to Know Before Injection
Every procedure carries risk. NICE guidance on foam asks clinicians to tell patients about reports of temporary chest tightness, dry cough, headaches and visual disturbance, and about rare but significant complications including heart attack, seizures, mini-strokes and stroke, which it links to foam bubbles travelling beyond the vein. In the Danish trial, one pulmonary embolism occurred among the patients treated with foam.
Closer to the skin, brown staining and a blush of fine red vessels can follow injection of a varicose branch. Why they appear and how they fade is covered in pigmentation and matting after sclerotherapy.
Dr. Soroush Sohrabi is a UK-trained Consultant Vascular and Endovascular Surgeon (FRCS, CCT) practising in Dubai, with a Cleveland Clinic Advanced Endovascular Fellowship and 77 peer-reviewed publications.
Choosing a Surgeon Who Treats Trunk and Branches
Look for a surgeon who scans the trunk before injecting the branches and can close a leaking trunk by ablation, so injection is chosen because it suits the vein. Dr. Sohrabi holds the FRCS in Vascular Surgery and a CCT, performs and interprets his own duplex scans, closes leaking trunk veins by ablation and treats varicose, reticular and spider veins with sclerotherapy. Book a consultation to have your veins mapped and your options set out.
About the Author
Dr. Soroush Sohrabi MD, PhD, FRCS, CCT (UK), PGCert, MCPhleb is a Consultant Vascular and Endovascular Surgeon practising in Dubai. He trained in the United Kingdom and holds a Fellowship of the Royal College of Surgeons (FRCS) in Vascular Surgery and a Certificate of Completion of Training (CCT). He has published 77 peer-reviewed papers with over 1,183 academic citations and is a member of the European Society for Vascular Surgery (ESVS) and the Vascular Society of Great Britain and Ireland (VSGBI). He is licensed by the UK General Medical Council (GMC No. 5207627) and the Dubai Health Authority (DHA No. 48905551).
Medically reviewed by Dr. Soroush Sohrabi MD, PhD, FRCS, CCT, Consultant Vascular and Endovascular Surgeon, October 2026.
References
National Institute for Health and Care Excellence. Varicose veins: diagnosis and management (CG168), Recommendations. https://www.nice.org.uk/guidance/cg168/chapter/Recommendations
NHS. Varicose veins. https://www.nhs.uk/conditions/varicose-veins/
National Institute for Health and Care Excellence. Ultrasound-guided foam sclerotherapy for varicose veins (HTG301, formerly IPG440), Recommendations. https://www.nice.org.uk/guidance/htg301/chapter/1-Recommendations
Gloviczki P, Lawrence PF, Wasan SM, et al. The 2023 Society for Vascular Surgery, American Venous Forum, and American Vein and Lymphatic Society clinical practice guidelines for the management of varicose veins of the lower extremities. Part II. Journal of Vascular Surgery: Venous and Lymphatic Disorders. 2024;12(1):101670. https://doi.org/10.1016/j.jvsv.2023.08.011
de Roos KP, Nieman FH, Neumann HA. Ambulatory phlebectomy versus compression sclerotherapy: results of a randomized controlled trial. Dermatologic Surgery. 2003;29(3):221-226. https://doi.org/10.1046/j.1524-4725.2003.29053.x
Khunger N, Sacchidanand S. Standard guidelines for care: sclerotherapy in dermatology. Indian Journal of Dermatology, Venereology and Leprology. 2011;77(2):222-231. https://doi.org/10.4103/0378-6323.77478
Cleveland Clinic. Sclerotherapy: Treatment and Recovery. https://my.clevelandclinic.org/health/treatments/6763-sclerotherapy
Vähäaho S, Halmesmäki K, Albäck A, et al. Five-year follow-up of a randomized clinical trial comparing open surgery, foam sclerotherapy and endovenous laser ablation for great saphenous varicose veins. British Journal of Surgery. 2018;105(6):686-691. https://doi.org/10.1002/bjs.10757
Hamann SAS, Giang J, De Maeseneer MGR, et al. Five year results of great saphenous vein treatment: a meta-analysis. European Journal of Vascular and Endovascular Surgery. 2017;54(6):760-770. https://doi.org/10.1016/j.ejvs.2017.08.034
Lawaetz M, Serup J, Lawaetz B, et al. Comparison of endovenous ablation techniques, foam sclerotherapy and surgical stripping for great saphenous varicose veins. Extended 5-year follow-up of a RCT. International Angiology. 2017;36(3):281-288. https://doi.org/10.23736/S0392-9590.17.03827-5
Rasmussen LH, Lawaetz M, Bjoern L, et al. Randomized clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins. British Journal of Surgery. 2011;98(8):1079-1087. https://doi.org/10.1002/bjs.7555
