Table 5.

Treatment of contrast media extravasation (CMEX)

	Mechanisms and discussion of evidence
Conservative Treatments
Aspiration of contrast whilst cannula still in place prior to removal.	This reduces the volume of contrast extravasate and reduce pressure [57].
Raise the affected limb if possible.	Minimise oedema by reducing hydrostatic pressure and promoting drainage [58].
Cooling of the region.A cold compress 15 to 60 minutes three times per day for a period of 3 to 4 days [1].	Anti-inflammatory effect via vasoconstriction and is widely recommended when treating CMEX [1, 13, 59].
Warming of the region.	Controversially, some think that cooling can delay resorption of extravasate, and warming can lead to vasodilation hence increasing contrast media (CM) resorption. Hastings-Tolsma et al. conducted studies with saline, assessing extravasation by the effect of both warming and cooling extremities [60]. No significant difference was observed between groups in terms of surface area induration, or evidence of extravasate taking longer to resorb when warm solution was applied.
Heparin ointment dressing with cooling (where the dermis is intact).	Anecdotal use has been suggested in a recent review paper by Mandlik et al. [12].
Topical non-steroidal anti-inflammatory drugs (NSAIDs).	Evidence only pertains to the analgesic effects on acute pain and not specifically extravasation [61].
Invasive treatments
Hyaluronic acid injection (HYLA). Dose of between 5–250 Units is thought to be most effective [15].	This mucopolysaccharide is injected directly into the site of CMEX and is thought to work by enzymatically cleaving structures of the interstitium thus promoting resorption into vessels and lymphatics. Limited evidence supporting its use [62]. Indeed, some data does not support its use as some animal models have shown an increased inflammatory response [63]. Overall, not considered routine treatment (only off-label use e.g. inoperable patients with compartment syndrome due to CMEX).
Aspiration & irrigation: essentially “wash-out” using stab incisions around the area of concern under local anaesthetic and extravasate aspirated with blunt suction cannulas. This is followed by irrigation (performed within 6 hours).	There is variation as to the exact technique, based on a retrospective study by Gault in 96 patients with extravasation,  44 were successfully treated [64]. However, only 1 patient had a CMEX (others being chemotherapy agents etc.) meaning it may be less applicable to CMEX. Further case series of 11 patients by Vandeweyer et al. described successful use, although this was with high osmolarity, ionic agents [65]. Overall, this is a mechanistically plausible method but without strong evidence base for routine use.
Manual squeezing technique: manual expression of extravasate after various punctures/stab incisions (e.g. 5–10 stabs with 18G needle).	Study by Tsai et al. of 8 cases who developed vascular compromise with 50 - 80 ml of non-ionic, low osmolarity extravasate demonstrated satisfactory healing using this method [66]. A similar study by Kim et al. with 23 cases (no control group) of extravasate > 50 ml also showed satisfactory response after 1 week follow-up although there was immediate temporary mild blistering [67]. A similar technique whereby multiple stab incisions were made for large volume extravasations was found to be successful in a case report by Raveendran et al. [68] Similar to other techniques, limited data available to support use of this, but the simplicity is attractive and more comparative data would help assess efficacy.
Fasciotomy and compartment release	Considered the definitive surgical treatment when a CMEX is complicated by neurovascular compromise or compartment syndrome. A retrospective study by Fallscheer et al., identified seven patients required fasciotomy [54]. Delay to refer to plastic surgery by >300 minutes is the greatest risk factor contributing to complications post-operatively.