Should foam made with physiologic gases be the standard in sclerotherapy?

The aim of this paper is to look at the pros and cons of using physiologic gas to produce foam for use in sclerotherapy. With the expanding use of foam sclerotherapy, there have been increased reports of transient neurologic adverse events such as visual disturbance. Although rare, increased numbers of serious adverse events such as transient ischemic attacks (TIAs) and stroke have been described. These events are seen more often in patients who have migraine with aura and those with a right-to-left shunt.

A literature search of the databases Ovid and Google Scholar was performed for studies looking specifically at neurologic side effects associated with sclerotherapy and use of physiologic foams. Included studies were randomized controlled trials, meta-analyses, review articles, observational studies and case studies.

Although physiologic gases have been shown in several studies to reduce the incidence of visual disturbance, increasing evidence from recent studies suggest endothelin, rather than gas bubbles to be the cause of these side effects. The cause of stroke and TIA has not been proven and occlusion of cerebral arterioles from gas emboli should still be considered. Many authors state that only good quality foam be injected and volumes should be kept low in an attempt to prevent these rare, but potentially serious events. Foam made with physiologic gases are more biocompatible compared to air-based foam and have been found to be at least as effective in sclerotherapy as foam made with room air.

The use of physiologic gases should be considered for those at increased risk of neurologic side effects such as migraineurs with aura and those with a known PFO. Additionally, as there are few disadvantages to the use of physiologic foam, the use of CO2 or CO2/O2 foam should be considered in all patients receiving foam sclerotherapy.