RESUMO
BACKGROUND: Foam sclerotherapy is an effective treatment for varicose veins and venous malformations, with its efficacy influenced by foam stability. The methods for preparing physician-compounded foam (PCF) are the double syringe system (DSS) and Tessari method. Few studies have been performed to compare the PCF stability produced by the 2 methods and their mechanisms. We aim to compare the stability of PCF produced by 2 two methods in the same connector and explore the reasons for the difference. METHODS: Foam was generated by the 2 methods under different circumstances. In the Tessari method, 2 syringes were connected at right angles (90°) by a 3-way tap. In the DSS method, 2 syringes were connected by the same 3-way tap in a straight line (180°). The stability and uniformity of foam produced by the 2 methods were compared using foam half-time and optical microscopy, respectively. Assuming that the difference in foam stability between the 2 methods was related to the angles of a connector, we compared the foam stability when 2 syringes were connected with a plastic connector bent to different angles. RESULTS: The DSS method could produce more uniform foam with longer foam half-time than the Tessari method, which was related to the angle of the connector. CONCLUSIONS: The stability of PCF is influenced by the angle of the connector.