Iodinated Contrast Media Extravasation Injuries: Should Osmolality and the Pattern of Distribution Affect Management?: A Literature Review and Case Report Comparison

Extravasation injuries with significant complications are uncommon and usually occur where the substance in question is a cytotoxic chemotherapeutic agent or a substance with a high toxicity. Contrast Media Extravasation Injuries (CMEI) are relatively benign in comparison to these but have the potential to result in serious complications including pressure necrosis, blistering, and compartment syndrome. Volume, rate of infusion, and osmolality all influence the distribution pattern of the injectate. “Large-volume” extravasations have been described in the literature as being from > 20 mL to > 100 mL.

CMEI often present in the initial phases with pain, gross edema, and erythema. A variety of management options have been described in an effort to avoid later complications. These include hyaluronidase injection with saline washout and liposuction, aspiration or stab incisions followed by compression, and fasciotomy if compartment syndrome is suspected. Conservative management has become more accepted in recent years after several studies showed that the pain and edema resolve well without surgical intervention.^1-3

As noted by other articles, when these management options were historically considered a clear delineation was not always made between contrast media and more toxic substances, prompting a low threshold for early surgical intervention.^4,5 Previous studies have advocated early formal surgical exploration based both on volume and on clinical symptoms.^6,7 Likewise, differences between older high osmolar contrast solutions and newer lower osmolar solutions were not always distinct. The lower osmolar solutions cause fewer complications, and although they can still occur, this is an important factor in considering management.^8-10

The area of distribution of the contrast medium may alter the efficacy of evacuation techniques. If the contrast medium is reasonably well contained within a local area and has not been diffusely distributed, this can make it possible to evacuate at the bedside.

Cellular osmolality is between 280 and 295 mOsm/kg H₂O. Despite the modern use of lower osmolarity solutions, all iodinated contrast media are still of a higher osmolality than this, which will cause edema in the interstitial space and intracellular dehydration. In severe cases this will cause release of inflammatory mediators and even cell death, causing de-epithelialization. Should the “vicious circle” of capillary ischemia and edema be initiated, compartment syndrome can result. Although there is little data focusing on the osmolality of the newer solutions in relation to the incidence of complications, it is easy to envisage a proportional relationship between the two. In clinical practice, there are too many variables to provide a clear relationship. The ionic or nonionic nature of the contrast medium has also been implicated, but no clear correlation has been made.

Conservative Management

The initial management of CMEI is well defined. The initial steps of stopping the infusion, attempting aspiration through the original cannula, splinting and elevating the limb, and applying cooling attract little controversy. Cohan described 22 cases of CMEI > 30 mL, none of whom required surgery and had no long-term adverse effects, and Sistrom corroborated this with a study of 28 cases.3,¹¹ Ko et al successfully managed 9 cases of CMEI with up to 90 mL of various low-osmolar solutions conservatively, advocating the use of room temperature damp gauze rather than ice packs and Silvadene ointment with clobetasol cream.¹²

Wang et al performed the largest study, observing 442 CMEIs of low-osmolar solutions between 3 and 150 mL over a 5-year period—it is telling that all but one of these patients were managed conservatively and the blistering, edema, and pain that were features in some cases all resolved within weeks without surgical intervention.¹

These studies provide a convincing argument for nonoperative management of CMEI until signs of compartment syndrome develop; however, methods of evacuating the contrast medium may also play a prophylactic role in the development of compartment syndrome and in symptomatic relief.¹³

Needle Aspiration or Stab Incisions With Compression

Although conservative management is appropriate in the vast majority of CMEIs, more diverse presentations such as nerve compression or gross swelling with pain not consistent with compartment syndrome have prompted descriptions of other methods for relieving the pressure and evacuating fluid. Another indication is as a prophylactic procedure to avoid the development of future compartment syndrome.¹³

Tsai described a technique using an 18-gauge needle and “milking” the contrast medium towards the puncture holes when an indication of pain or vascular compromise of the fingers required it. This has the advantage of being quick and minimally invasive, so it can be performed soon after the extravasation before wider distribution of the substance.

Further to this, a description of using slit incisions with a similar “squeezing” technique was described by Kim as a way to minimise complications in CMEI > 50 mL. The slit incisions described here are centred over a discrete area of localised swelling rather than diffuse arm edema.¹⁴ Good results from this technique were confirmed by Raveendran et al, again in what appeared to be an area of well-defined local turgor.¹⁵

Stab Incisions With Liposuction

First described by Gault in a paper predominantly looking at management of cytotoxic media extravasation, the use of a hyaluronidase, blunt liposuction cannula, and saline injections to reduce the edema has shown good symptomatic relief.¹⁶ The incisions made for this are across the dorsum of a diffusely edematous forearm and hand, as opposed to the techniques used above that were confined to a small area. With subsequent external compression, it appears to be very effective at reducing the edema in cases where complications are progressing.  This was illustrated by Schavarian et al, who applied a Rhys-Davies exsanguinator with good results.⁵ In light of the data suggesting that conservative management is appropriate in most situations and because it requires a general anesthetic, this method should be reserved for higher volume cases where high-osmolar or toxic compounds have been used and there is a high risk of complications.

Fasciotomy

The progression to compartment syndrome is the main concern from these injuries, and its prevention is in part the basis for using the techniques described above. Most of the case reports of compartment syndrome appear to be in the hand; a recent review by Van Veelen et al found that 8 of 11 case studies of CMEI compartment syndrome were in the hand. The incidence of compartment syndrome was not clearly associated with higher patient risk factors for extravasation in general.¹⁷ Cohan had previously suggested that the volume injected bears no significant relationship to complication rate, with moderately severe complications resulting from small volumes (20 to 50 mL) and no complications arising from larger volumes (> 100 mL).¹⁸ Little mention has been made of the variable osmolarity of these solutions; however, examples of different solutions can be seen in Table 1 drawn from the case reports where they were detailed. The complications occur with varying osmolalities within this “low-osmolar” band, and it is difficult to establish a firm relationship between osmolality and complication rate within this range.

Case Report 1

A 67-year-old woman with a background of gout and a previous cerebrovascular accident was referred to the plastic surgery service following a computed tomography (CT) scan during which her venous access had failed, resulting in extravasation of approximately 150 mL of iodinated contrast (Omnipaque 350; GE Healthcare Systems) from a cannula in her right antecubital fossa. Upon clinical review within the hour following the episode, she was systemically well but had a diffusely edematous arm that was painful and erythematous. Following systemic assessment, the arm was elevated and management plans were considered.

A plain x-ray of the arm had been taken shortly after the injury and is shown at Figure 1, displaying the diffuse nature of the extravasation in this case. Unfortunately, the cannula had been removed prior to review and could not be used for aspiration. In view of the extent of the edema and the presence of pain, evacuation of the fluid was attempted. This was initially performed with a needle aspiration, which was ineffective, and subsequently with stab incisions.

Approximately 10 small incisions were made under local anesthetic to the affected area and manual compression applied, with the evacuation of a small amount of fluid and a slight improvement in symptoms; however, the edema did not noticeably improve. After a period of observation where there was no apparent progression of symptoms, further surgical evacuation was decided against.

Following this, the wounds were dressed, and the patient was elevated in a Bradford sling. The patient refused an offer of admission and was given advice to return if there was any deterioration or signs of compartment syndrome.

The patient was reviewed 3 days later where the edema and erythema had resolved. Approximately 1% total body surface area epidermolysis had occurred over the dorsal forearm, which was managed with simple dressings over the following weeks. There were no long-term effects from this CMEI.

Case Report 2

An 87-year-old man with a background of prostate cancer and Parkinson disease suffered a CT contrast extravasation injury to the left antecubital fossa of approximately 100 mL of iodinated contrast (Omnipaque 350; GE Healthcare Systems). The cannula was removed by the radiology department and a cool pack applied; however, the skin overlying the area became rapidly erythematous and epidermolytic in an area corresponding to 0.75% total body surface area.

A plain x-ray of the arm was taken and is shown in Figure  2, displaying a well-localized collection in a more discrete distribution when compared with Case 1.

Multiple stab incisions were made to the area with successful aspiration of the contrast medium and subsequent irrigation with saline. This resulted in improved comfort and reduction of swelling. This case met with more success using this technique than that of Case 1.

This patient was admitted for elevation and analgesia, was sent home with oral antibiotics, and was reviewed in the dressing clinic a week late and discharged with no long-term effects from the injury.

There are a variety of techniques that can be used in the management of CMEI due to the variation in severity and presentation. Treatment options can range from simple elevation and analgesia to operative intervention if complications such as compartment syndrome are suspected. Clinical judgment should remain the main basis of the management decision. Iodinated contrast is considered relatively benign when compared with more toxic substances such as cytotoxic drugs. Most can be managed conservatively with good results, but in cases where more severe symptoms are developing the techniques described above can be helpful.

Plain radiography is a useful adjunct to confirm the extent of the dissemination in CMEI, as it may aid in determining management strategy. Most cases advocating bedside evacuation in the literature describe a localized collection. In Case 1 the contrast was not in a well-defined space, appearing to have progressed along the suprafascial plane and distributed widely after only a short period of time. This made the attempt at aspiration less useful. This is highlighted by comparison with Case 2 where the contrast has occupied a well-defined area, rendering it amenable to direct evacuation. A similar pattern of distribution to Case 1 was illustrated by Schaverian that responded very well to the same pattern of stab incisions, but only after general anesthesia, liposuction, and exsanguinator compression.⁵ This was not considered appropriate in either of the patients reported here as there were no signs of nerve compression, and progression of symptoms was halted after the bedside intervention. An adjunct that could also have been considered was the bedside use of the Rhys Davies exsanguinator; however, this is only effective following previous liposuction and is likely to have caused discomfort without anesthesia.

Following review of the literature, it seems that in the majority of patients conservative management of CMEI is the most appropriate course. The use of stab incisions at the bedside should be reserved for those collections that are more tense and well localized. When presented with the diffusely edematous arm, multiple incisions over the dorsum of the arm followed by compression may provide some symptomatic relief but will not resolve the edema without formal liposuction in theater. The resolution of the edema is likely to have the greatest contribution to relief of symptoms such as nerve compression, but the benefit of this should be weighed against the risks of the procedure and of the anesthetic.

Extravasation of volumes of contrast over 100 mL is uncommon, accounting for 10% of total injuries.¹⁹ These injuries are frequently managed conservatively; however, those patients with pain and progressive symptoms may benefit from surgical intervention. There is no firm consensus on the best method of managing these injuries and when to pursue a surgical course. The bedside evacuation methods described may only be effective in localized collections, and in the more widely distributed injuries with diffuse edema or risk of tissue damage, any marked improvement will only be obtained under theater conditions with formal anesthesia.

Affiliations: ¹Royal Devon and Exeter Hospital, Exeter, Devon, UK; ²Derriford Hospital, Plymouth, Devon, UK

Correspondence: Robert Thomas; rlt@doctors.org.uk

Disclosures: The authors have no relevant financial or nonfinancial interests to disclose.