Current European Society of Vascular Surgery guidelines for venous thromboembolism (VTE) prophylaxis after endovenous varicose vein interventions stipulate that an individualised VTE risk assessment for every patient undergoing varicose vein surgery(1). Although anticoagulants are commonly administered following varicose vein surgery, there is a lack of consensus as to the optimal pharmacological thromboprophylaxis strategy following endovenous varicose vein intervention(2). A systematic review and meta-analysis was performed to elucidate the rate of deep venous thrombosis (DVT), pulmonary embolism (PE), endovenous procedure induced thrombosis (EHIT) and overall rate of thrombotic complications after endovenous intervention with mechanical thromboprophylaxis measures and additional pharmacological thromboprophylaxis compared to mechanical measures alone.

The review followed PRISMA guidelines using a registered protocol (PROSPERO: CRD42021274963). MEDLINE, Embase, the Cochrane Controlled Trials Register, Clinicaltrials.gov, European Union Clinical Trials and the International Standard Randomised Controlled Trial Number Registry were searched up until December 2021. Articles were included if they documented the rate of deep venous thrombosis or pulmonary embolism after any endovenous treatment of superficial venous incompetence in more than 30 patients. Articles were screened against the eligibility criteria and discrepancies mediated by an independent third reviewer. Data were pooled with a fixed effects model via a meta-proportions analysis.

Two-hundred and twenty-one studies (476,266 participants) were included in the quantitative analysis. For randomised trial arms, the rate of DVT with dual prophylaxis was 0.52% (95% CI 0.23-1.19%) (9 studies; 1095 patients; 2 events) (Figure 1), compared to 2.26% (95% CI 1.81-2.82%) (37 studies; 6951 patients; 69 events) with mechanical prophylaxis alone (Figure 2). Across all prospective study designs, the rate of DVT in mechanical plus pharmacological prophylaxis was 0.73% (95% CI 0.52-1.02%) (31 trial arms, 6151 participants, 23 events), versus 1.31% (95% CI 1.16-1.48%) (123 trial arms, 36,418 participants, 214 events). Due to high heterogeneity in the combined prospective and retrospective studies, data pooling was precluded. The rate of PE in randomised trial arms was 0.45% (95% CI 0.09-2.35) (5 studies, 460 participants, 1 event, I2=0%) versus 0.23% (95% CI 0.10-0.52%) (28 studies, 4834 participants, 3 events) for mechanical prophylaxis alone. The rate of EHIT class III-IV was 0.35% (95% CI 0.09-1.40) (3 studies, 822 participants, 5 events) versus 0.88% (95% CI 0.28-2.70%) (11 studies, 48,177 participants, 155 events). There was one VTE-related mortality and one instance of major bleeding following anticoagulant and non-steroidal anti-inflammatory co-administration. Taking the rate of DVT, PE and EHIT class III-IV, the total rate of thrombotic complications after pharmacological in addition to mechanical thromboprophylaxis was 1.22% (95% CI 0.68-2.71) versus 2.35% (95% CI 1.59-4.36) with mechanical prophylaxis alone.

This meta-analysis demonstrates a significant reduction in the rate of DVT with additional pharmacological thromboprophylaxis and supports the routine prescription of anticoagulation for endovenous varicose vein intervention. Randomised interventional studies are critical to establish the clinical effectiveness and safety of additional pharmacological thromboprophylaxis.

1. De Maeseneer MG, Kakkos SK, Aherne T, et al. Editor's Choice - European Society for Vascular Surgery (ESVS) 2022 Clinical Practice Guidelines on the Management of Chronic Venous Disease of the Lower Limbs. Eur J Vasc Endovasc Surg. Feb 2022;63(2):184-267. 2. Dattani N, Shalhoub J, Nandhra S, et al. Reducing the risk of venous thromboembolism following superficial endovenous treatment: A UK and Republic of Ireland consensus study. Phlebology. Oct 2020;35(9):706-714.