Carbon dioxide, gadolinium prove safe and useful in uterine fibroid treatment

Carbon dioxide and gadolinium are safe and effective contrast media for uterine artery embolization, according to a study from Johns Hopkins University. Their use provides an alternative for patients who are allergic to conventional iodinated contrast agents, and low doses reduce risk of nephrogenic systemic fibrosis.

About 10% of women who undergo embolization of uterine fibroids may suffer adverse reactions to the iodinated contrast media used during fluoroscopy-guided procedures. Most adverse reactions are mild or moderate, but some can carry a significant life-threatening risk.

Carbon dioxide has been used as an alternative to conventional contrast agents in several clinical applications. The gas is 400 times less viscous than iodinated media, making it especially well suited for the handling and visualization of small vessels, according to the investigative group led by Dr. Hyun S. Kim, an assistant professor of radiology at Hopkins.

Kim and colleagues evaluated the safety and clinical outcomes of uterine artery embolization with carbon dioxide and a gadolinium-based agent in eight patients with symptomatic fibroids. The patients underwent angiography after injection of about 30 to 40 mL of carbon dioxide using a commercially available microcatheter system. They then received the embolization agent mixed with a dose of the gadolinium-based contrast agent (mean 30.6 mL). The technique allowed visualization while keeping gadolinium dose low.

The investigators found that carbon dioxide and gadolinium worked safely and effectively as contrast media in this group of patients without major complications. They published their findings in the August issue of the Journal of Vascular and Interventional Radiology.

"Our study adds further evidence of the safety and feasibility of UAE without the use of iodinated contrast media to that presented in a case report describing the use of CO2 gas to guide UAE," the researchers said.

The procedure, lasting about 15 minutes under fluoroscopy, led to significant symptom improvement in all patients, with a mean reduction in leiomyoma volume of 42%. Patients underwent follow-up at 24 hours, one month, and six months after embolization, and yearly thereafter. No repeat interventions have been performed to date.

The small study sample and selection bias for patients with contraindications to iodinated contrast media represented major limitations to the study, according to the researchers. In addition, the technique may not be appropriate for morbidly obese women and for those with gigantic leiomyomata. It provides several advantages, however, including carbon dioxide's low cost and lack of nephrotoxicity and a decreased risk of nephrogenic systemic fibrosis from gadolinium use.

Embolization with CO2 and a gadolinium-based contrast medium as alternative agents should be considered a viable treatment in patients with symptomatic uterine leiomyomata who suffer from severe allergies to conventional iodinated contrast media or renal impairment, the researchers said.

"The use of these alternative agents expands the possibilities of treatments for patients with symptomatic leiomyomata who had previously not been able to benefit from endovascular intervention," they said.

For more information from the Diagnostic Imaging archives:

Gelatin microspheres may set new embolization standard

Fibroid embolization agent influences treatment result

Fibroid therapy stays on minimally-invasive path