Role of injection pressure, flow and sclerosant viscosity in causing cutaneous ulceration during sclerotherapy

Abstract

The objective of the study is to evaluate the viscosity of popular sclerosants and their flow hydrodynamics through a syringe/needle to further discuss Miyake's old, venous-capillary reflux theory, using additional objective data. The following sclerosing agents were tested in the study: 75% dextrose (D75%); 50% dextrose (D50%); 5% ethanolamine oleate (Etha5%); 0.5% laureth-9 (Aet0.5%) and 0.1% sodium tetradecyl sulphate (STS0.1%). Using 5 mL syringes and 27G needles, the resulting pressures and flows for each sclerosant agent were measured. To do this, a three-way stopcock was connected between the syringe and the needle so that an arm of the stopcock could be used to measure injection pressures with a digital monitor in 1 mmHg increments. Two trials were performed: in trial 1, the syringe was attached to a Samtronic 680 infusion pump and in trial 2, the solutions were injected manually. The observed sclerosant viscosities were as follows: D75%: 0.28 Poise; D50%: 0.12 Poise; Etha5%: 0.10 Poise; Aet0.5%: 0.07 Poise; and STS0.1%: 0.04 Poise. In trial 1 (constant flow), it was observed that D75%, which had the highest viscosity of the sclerosants tested, had the highest pressure readings. In trial 2 (constant pressure), the flow obtained with the D75% solution was lower than the flow of the other solutions. In conclusion, based on the rabbit study theory, vessel size and sclerosant viscosity and strength, not extravasation, play a role in causing ulceration from injection sclerotherapy. As a result, they all affect the potential of venous-capillary reflux being caused by sclerotherapy injection and, thus, the risk of postsclerotherapeutic cutaneous ulceration.

Safety Concerns for Sclerotherapy of Telangiectases, Reticular and Varicose Veins

“…However, it is usually reported after perivascular injection of sclerosants in higher concentrations and rarely after properly performed intravascular injections of sclerosants in various concentrations, that is, 0.5% polidocanol in the treatment of spider veins [12] . A relevant study has examined the experimental potential of liquid and foamed polidocanol in causing skin necrosis, when injected into the superficial subcutaneous tissue of rats and has showed that quantities of up to 0.5 ml of 0.5% polidocanol, as either a liquid or foam, do not induce visible skin necrosis [24] . In addition, experimental data show that the likelihood of cutaneous necrosis depends on the pressure of injection and the diameter of the vessel, that is, the greater the pressure the greater the likelihood of cutaneous necrosis and the smaller the vessel the greater the likelihood of cutaneous necrosis.…”

“…Detergent sclerosants are the least viscous. On the other hand, 75% dextrose has been reported to cause minor skin necrosis when extravasated and when this occurs, it causes a superficial 1-2 mm scar that heals in 1 or 2 weeks [24] .…”

“…One case of septicaemia has been reported in a multicenter prospective study of foam sclerotherapy of great and small saphenous veins including 1,025 patients [24] . The case occurred in a 42-year-old woman following an injection with a direct puncture into the great saphenous vein of foam prepared with polidocanol 3% mixed with air.…”

Cryo-laser and cryo-sclerotherapy guided by Augmented Reality

“…The low index of complications of this allergy-free therapeutic method is very appealing to phlebologists willing to treat telangiectasias with feeder veins (12,15,16).…”

Sclerotherapy – How to Achieve a Spectacular Outcome

“…Rather, inadvertent passage of sclerosant into small arterioles is likely the cause of most skin necrosis. This can occur when injection pressure exceeds capacity of the vein, causing venous-capillary reflux into the surrounding arterioles [31].…”