Varicose vein surgery and deep vein thrombosis prophylaxis. Over 60, 000 varicose vein related operations occur each year in the UK,1 the vast majority of ...
Editorial
Varicose vein surgery and deep vein thrombosis prophylaxis Over 60, 000 varicose vein related operations occur each year in the UK,1 the vast majority of which are elective day cases. The development of a perioperative deep vein thrombosis is reported at a rate of less than 1%.2 The benefits of routine deep vein thrombosis (DVT) thromboprophylaxis in abdominal and pelvic surgery is well documented.3 However, its role in varicose vein surgery is less clear with no absolute agreement at present. In an era where policies and guidelines dominate, these authors’ hospital trust issues a single protocol on ‘blanket prophylaxis’ of low molecular weight heparin and anti-embolic stockings for ‘every patient undergoing surgery with general anaesthesia’.4 However, it is evident that vascular surgeons across the country vary in opinion about such a ‘blanket’ protocol. Certainly, one recent questionnaire of vascular surgeons in the UK, in 2005, revealed that only 12% of surgeons used heparin routinely in varicose vein surgery,5 and another that 1.4% never used heparin thromboprophylaxis.6 Many surgeons believe that groups undergoing varicose vein surgery within the ‘low-risk’ category of surgery lasting less than 30 min or aged 40 years or less do not require heparin prophylaxis. This is supported by a retrospective study done over four years involving 2186 patients, which showed that the 903 patients who did not receive heparin thromboprophylaxis did not go on to suffer a venous thromboembolism in the three-month postoperative period.7 Furthermore, in a procedure which often results in a degree of bruising postoperatively, it is argued that routine use of heparin thromboprophylaxis may actually worsen such bruising or lead to haematoma formation,3 a common and troublesome side-effect, which surgeons aim to avoid, and therefore should be used in selective cases only. In support of this, the current North American guidelines8 are similar to those of the Scottish Intercollegiate Guideline Network.9 Both recommend that only patients with risk factors should receive DVT prophylaxis for varicose vein surgery. Such risk factors would include obesity or a previous or family history of DVT.5 Other prophylactic methods that may be employed in general surgical procedures, such as pneumatic foot pumps and intraoperative anti-
embolic stockings, are considered impractical, inconvenient and therefore less popular in varicose vein surgery. Finally, the rise of day-case treatment for varicose veins means that the majority of patients are mobile almost immediately and are often discharged with the use of elastic antiembolism stockings, all of which may reduce the incidence of perioperative DVT.10 However, reliable data on the incidence of DVT following varicose vein surgery randomized controlled studies are lacking. A group of surgeons from Geneva reported six cases of clinically confirmed pulmonary embolism out of 1063 cases of varicose vein stripping procedures over a 10year period. This incidence of pulmonary embolism (0.56%) was comparable to that seen in abdominal surgery.11 However, a study from New Zealand showed that 5.3% of patients within the study developed a DVT following varicose vein surgery, an incidence higher than previously reported values. The authors suggest that previous study estimates were made on clinical grounds and were not confirmed by imaging techniques; therefore, asymptomatic cases of DVT went unnoticed and unreported at the time of study.12 There is also evidence to suggest that those patients given DVT prophylaxis were not necessarily protected from the development of a DVT. One study reported that of the 20 out of 377 patients that developed a DVT, 14 had received prophylactic subcutaneous low molecular weight heparin.12 Another reported how four out of 1283 patients, who received heparin prophylaxis, developed a thromboembolism.7 This would suggest that those patients who are considered at high risk, such as those with obesity, with a past medical or family history of thromboembolism, may not be protected by a blanket policy or have to accept that they are at a higher risk of venous thromboembolism. The use of hormone therapy is also controversial. While the Royal College of Obstetricians and Gynaecologists stated, in 1995, that ‘there was insufficient evidence to support a policy of routinely stopping the oral contraceptive pill (OCP) prior to major surgery’, a questionnaire in 1999 revealed that 74% of surgeons stopped the oral contraceptive prior to surgery.12 It is debatable whether the risk of stopping oral contraceptives
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Editorial
D Abbott et al.
4–6 weeks before surgery, and the possibility of unwanted pregnancy or termination may be avoided by the administration of prophylaxis against DVT. In summary, DVT is a rare but significant complication associated with varicose vein surgery. Even the role of prophylaxis in newer endovascular laser techniques is yet to be evaluated.13 However, as little as 29%5 of vascular surgeons consider varicose veins themselves to be an independent risk factor for the development of thromboembolism, and only a minority give low molecular weight heparin routinely in such surgery. Many surgeons do, however, discharge their patient with a thromboembolic deterrent stocking on the operated limb. Is this for patient comfort or prophylaxis? While it is clear from the literature that several common patterns of thought exist, there is currently no absolute set of guidelines advising as to the use of DVT prophylaxis in varicose vein surgery. There is the need for evidence-based guidelines in the prevention of DVT in patients undergoing venous procedures.
D Abbott, B Dharmarajah and A H Davies Department of Vascular Surgery, Imperial College, Charing Cross Hospital, London, UK
References 1 Tennant WG, Ruckley CV. Medicolegal action following treatment for varicose veins. Br J Surg 1996;83:291–2
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2 Miller GV, Sainsbury JRC, Lewis WG, Macdonald RC. Morbidity of varicose vein surgery: auditing the benefit of changing clinical practice. Ann R Coll Surg Engl 1996;78:345–9 3 Clagett GP, Reisch JS. Prevention of venous thromboembolism in general surgical patients: results of meta-analysis. Ann Surg 1988;208:227–40 4 Howard A, Greenhalgh RM, Frankel A. Towards a single protocol for the prophylaxis of venous thromboembolic disease. Hammersmith Hospitals NHS Trust 2003 5 Campbell WB, Ridler BMF. Varicose vein surgery and deep vein thrombosis. Br J Surg 1995;82:1494–7 6 Winterborn RJ, Campbell WB, Heather BP, Earnshaw JJ. The management of short saphenous varicose veins: a survey of the members of the vascular surgical society of Great Britain and Ireland. Eur J Vasc Endovasc Surg 2004;28:400–3 7 Enoch S, Woon E, Blair SD. Thromboprophylaxis can be omitted in selected patients undergoing varicose vein surgery and hernia repair. Br J Surg 2003;90:818–20 8 Hirsch J, Dalen J, Guyatt G. The sixth (2000) ACCP guidelines for antithrombotic therapy and venous thrombosis. American College of Chest Physicians. Chest 2001;119(Suppl):1S–2S 9 Scottish Intercollegiate Guideline Network. Guideline no. 62http://www.sign.ac.uk 10 Lees TA, Beard JD, Ridler BMF, Szymanska T. A survey of the current management of varicose veins by members of the Vascular Surgical Society. Ann R Coll Surg Engl 1999;81:407–17 11 Bounameaux H, Huber O. Postoperative deep vein thrombosis and surgery for varicose veins. BMJ 1996;312:1158 12 Van Rij AM, Chai J, Hill GB, Christie RA. Incidence of deep vein thrombosis after varicose vein surgery. Br J Surg 2004;91:1582–5 13 Mundy L, Merlin TL, Fitridge RA, Hiller JE. Systematic review of endovascular laser treatment for varicose veins. Br J Surg 2005;92:1189–94
