Invited commentary

Abstract

During the past decade, foam sclerotherapy has been widely used around the world for treatment of varicose veins, for ablation of the incompetent saphenous veins, for perforating veins, or for treatment of venous malformations. Although liquid forms of the two most frequently used sclerosing agents, sotradecol and polidocanol, are now approved by the Federal Drug Administration (FDA), the use of foam has no FDA approval in the United States. Two European consensus meetings concluded that foam sclerotherapy was a safe, effective, and minimally invasive treatment of varicose veins with a low rate of complications.1Breu F.X. Guggenbichler S. European Consensus Meeting on Foam Sclerotherapy, April, 4-6, 2003, Tegernsee, Germany.Dermatol Surg. 2004; 30 (discussion 717): 709-717Crossref PubMed Scopus (173) Google Scholar, 2Breu F.X. Guggenbichler S. Wollmann J.C. 2nd European Consensus Meeting on Foam Sclerotherapy 2006, Tegernsee, Germany.Vasa. 2008; 37: 1-29PubMed Google Scholar Reported complications of foam sclerotherapy have been indeed rare.3Smith P.C. Chronic venous disease treated by ultrasound guided foam sclerotherapy.Eur J Vasc Endovasc Surg. 2006; 32: 577-583Abstract Full Text Full Text PDF PubMed Scopus (173) Google Scholar In a prospective multicenter study, Guex et al4Guex J.J. Allaert F.A. Gillet J.L. Chleir F. Immediate and midterm complications of sclerotherapy: report of a prospective multicenter registry of 12,173 sclerotherapy sessions.Dermatol Surg. 2005; 31 (discussion 128): 123-128Crossref PubMed Google Scholar reported on side-effects of 12,173 sclerotherapy sessions, 6739 performed with foam. Forty-nine incidents (0.4%) occurred, 37 after administration of foam. There were 20 cases of transient visual disturbances; in 19 cases, foam or air block was used. One patient developed femoral vein thrombosis. In a systematic review of data of more than 9000 patients who underwent foam sclerotherapy, the rate of serious adverse effects, including pulmonary embolism and deep vein thrombosis, was less than 1%. The median rate of visual disturbance was 1.4%, headache occurred in 4.2%, and thrombophlebitis in 4.7%. Concerns about the use of foam have been raised when Bush5Bush R.G. Derrick M. Manjoney D. Major neurological events following foam sclerotherapy.Phlebology. 2008; 23: 189-192Crossref PubMed Scopus (124) Google Scholar and other authors6Picard C. Deltombe B. Duru C. Godefroy O. Bugnicourt J.M. Foam sclerotherapy: a possible cause of ischaemic stroke?.J Neurol Neurosurg Psychiatry. 2010; 81: 582-583Crossref PubMed Scopus (21) Google Scholar, 7Forlee M.V. Grouden M. Moore D.J. Shanik G. Stroke after varicose vein foam injection sclerotherapy [see comment].J Vasc Surg. 2006; 43: 162-164Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar reported on cases of stroke after foam sclerotherapy in patients who had a patent foramen ovale. Factors believed to increase the risk of stroke included the use of air instead of CO2 to prepare the foam, large amount (>20 mL) of foam used during one session, large bubble size, failure to elevate the limb after treatment, and prolonged immobility.6Picard C. Deltombe B. Duru C. Godefroy O. Bugnicourt J.M. Foam sclerotherapy: a possible cause of ischaemic stroke?.J Neurol Neurosurg Psychiatry. 2010; 81: 582-583Crossref PubMed Scopus (21) Google Scholar, 8Ceulen R.P. Sommer A. Vernooy K. Microembolism during foam sclerotherapy of varicose veins.N Engl J Med. 2008; 358: 1525-1526Crossref PubMed Scopus (98) Google Scholar, 9Morrison N. Cavezzi A. Bergan J. Partsch H. Regarding “Stroke after varicose vein foam injection sclerotherapy.”.J Vasc Surg. 2006; 44 (author reply 225-6): 224-225Abstract Full Text Full Text PDF PubMed Scopus (44) Google Scholar Standardization of the bubble size using commercially prepared microfoam10Wright D. Gobin J.P. Bradbury A.W. Coleridge-Smith P. Spoelstra H. Berridge D. et al.The Varisolve European Phase III Investigators GroupVarisolve polidocanol microfoam compared with surgery or sclerotherapy in the management of varicose veins in the presence of trunk vein incompetence: European randomized controlled trial.Phlebology. 2006; 21: 180-190Crossref Scopus (164) Google Scholar and the replacement of air with CO2 in the solution have been suggested to decrease the risk of neurologic complications.11Morrison N. Neuhardt D.L. Rogers C.R. McEown J. Morrison T. Johnson E. Salles-Cunha S.X. Comparisons of side effects using air and carbon dioxide foam for endovenous chemical ablation.J Vasc Surg. 2008; 47: 830-836Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar In a prospective, uncontrolled study published in this issue of the Journal of Vascular Surgery, Regan at al performed ablation of the great saphenous vein in 82 patients with chronic venous insufficiency using ultra-low nitrogen polidocanol microfoam. Sixty patients with evidence of microemboli in the middle cerebral artery were evaluated for microinfarction in the brain using magnetic resonance imaging (MRI) and for myocardial infraction measuring cardiac troponin-I. Eighty-one patients were followed for 28 days; duplex scanning confirmed occlusion of the saphenous vein in 88%. Only one patient (1.2%) had a transient (20 seconds long) visual disturbance, and none developed cerebral microemboli, myocardial infarction, or clinically significant pulmonary embolism. While this study demonstrated that microfoam treatment of the saphenous vein in 60 patients with right-to-left shunt did not cause cerebral infarction, the lack of a control group of patients with bedside preparation of the foam clearly weakens the value of the information. Even with a control group, the study would have a high chance for Type II error since many more patients are needed to show any difference in the risk of complications. The number of patients would depend on the rate of subclinical microemboli, detected by the authors' technique in patients treated with foam prepared from an air-sclerosing solution mixture: a study that alone is needed to give us valuable information on the risk of using room air in foam for sclerotherapy. The 10% risk of failed treatment by 28 days and other side-effects reported in this study are disconcerting. Adverse events included pain or discomfort in the treated limb in 45%, deep vein thrombosis occurred in 7.4%, and secondary procedures to express thrombus from the treated saphenous vein were needed in 13.5%. These complications are higher than what was reported in any previous study with foam, and further refinement of the technique presented here is clearly warranted. There is a great need for minimally invasive treatment of millions of people with chronic venous disease. Endovenous thermal ablation with radiofrequency or laser has been a major step in the right direction to replace the traditional high ligation and stripping in many patients. Foam is also here to stay for treatment of varicose veins;12Darvall K.A. Bate G.R. Adam D.J. Bradbury A.W. Recovery after ultrasound-guided foam sclerotherapy compared with conventional surgery for varicose veins.Br J Surg. 2009; 96: 1262-1267Crossref PubMed Scopus (32) Google Scholar, 13Darvall K.A. Bate G.R. Silverman S.H. Adam D.J. Bradbury A.W. Medium-term results of ultrasound-guided foam sclerotherapy for small saphenous varicose veins.Br J Surg. 2009; 96: 1268-1273Crossref PubMed Scopus (34) Google Scholar therefore, the authors' efforts to produce a safe product and a minimally invasive technique for venous ablation should be applauded. This prospective trial by Regan and colleagues was an important step in the right direction. However, further controlled clinical trials with a much larger number of patients are needed to answer two important questions on foam sclerotherapy: is ultra-low nitrogen polidocanol microfoam superior to room-air microfoam, and will ultra-low-nitrogen polidocanol microfoam prevent neurologic complications? Clinical significance of cerebrovascular gas emboli during polidocanol endovenous ultra-low nitrogen microfoam ablation and correlation with magnetic resonance imaging in patients with right-to-left shuntJournal of Vascular SurgeryVol. 53Issue 1PreviewFoam generated by manual agitation of liquid sclerosant with air or gas is routinely utilized to treat refluxing veins. Although generally well tolerated, serious neurological events have been reported. The composition and properties of the foam, including bubble size and gaseous components, may contribute to the potential for microcirculatory obstruction and cerebral ischemia. We tested an ultra-low nitrogen polidocanol endovenous microfoam with controlled bubble size and density and hypothesized that patients at risk due to the presence of middle cerebral artery (MCA) bubble emboli during microfoam injection would not demonstrate evidence of clinical or subclinical cerebral infarction. Full-Text PDF Open Archive