Deep vein thrombosis after sclerotherapy and endovenous laser ablation of varicose veins - an observational study.

Background: The risk of developing deep vein thrombosis (DVT) after endovenous ablation of varicose veins varies in the literature. Little is known about the characteristics of this complication and associated factors. This study aimed: 1) to study the occurrence of DVT after ultrasound-guided foam sclerotherapy (UGFS) alone or combined with endovenous laser ablation (EVLA) for lower-limb varicose veins; 2) to identify factors associated with DVT. Patients and methods: The study included all outpatients aged 18 years or older who underwent UGFS and EVLA or UGFS alone at the University Hospital of Zurich between 2011 and 2015. Data were extracted from the hospital electronic medical record. Patients were surveyed about their level of pain after the procedure and their level of satisfaction with the procedure. Duplex ultrasound was used to assess the deep venous system 7-10 days and 6-8 months after the procedure. Regression analysis was used to examine the association of patient and procedure characteristics with the development of DVT. Results: A total of 334 patients (561 procedures performed in 393 different sessions) were included: 73% of the patients underwent combined UGFS and EVLA and 27% underwent UGFS alone. DVT occurred in 24 (7.2%) patients, of whom 88% underwent combined procedures and 17% underwent interventions involving both the great and small saphenous veins on the same session. DVT occurred in 8.2% of patients receiving thromboprophylaxis and in 9.5% of patients not receiving thromboprophylaxis. DVT occurred in 5.2% of women and 11.9% of men. No factors associated with a diagnosis of DVT after intervention were identified. Pain and satisfaction levels did not differ between patients with and without DVT. Conclusions: This study adds to the knowledge of the risk of DVT following UGFS alone or combined with EVLA. Further studies are needed to revise thromboprophylaxis.