Iliac PTA under CO2 guidance

Clinical History

HIgh-grade iliac stenosis in a patient with a history of severe contrast media reaction

Imaging Findings

The psoriatic patient was suffering from left-sided claudications with a walking distance of less than 150 m (stage II b Fontaine) with the pain beginning at her thigh. She had experienced severe contrast reaction during a previous angiography while using contrast media requiring resuscitation. An eccentric stenosis of her left common iliac artery was known. It was decided to perform the intervention under the guidance of carbondioxide as a contrast medium and to avoid any exposure to iodinated contrast.

Discussion

After retrograde puncture of the left common femoral artery, repeat CO2 injections were performed via the sidearm of a 7 F sheath revealing a high grade stenosis of the left common femoral artery (Fig. 1 a). After passage of a coated guidewire, a balloon dilation was performed by use of a 7 mm balloon which was filled by saline instead of diluted contrast in order to avoid exposure to dye in case of balloon leakage (Fig. 1 b). After PTA over 60 s , a significant residual stenosis (Fig. 1 c) remained indicating stent implantation. A 7 F delivery system carrying a self-expanding nitinol stent of 8 mm diameter and 3 cm length (ZA stent, Cook Inc.) was advanced over the stenotic segment (Fig. 2 a). After stent delivery (Fig. 2 b) there was still a waist of the stent in place. Therefore an additional balloon dilation inside the stent was performed with a 7 mm balloon (Fig. 2 c). After PTA, the stent was nearly completely open with a discrete remaining waist but high flow was present (Fig. 2 d). In case of severe renal insufficiency or contrast intolerance, alternative guiding tools are requested. While MR-guided endovascular procedures are still in its infancy, alternative contrast agents might be used to avioid iodinated contrast material. Gadolinium DTPA is a useful agent to be used under subtraction technique; the total volume is however limited and it is relatively expansive. CO2, in contrast, is easy to apply, cheap and nearly unlimited concerning the applicable dosage. It is safe unless it is used in supraaortic vessels or the coronaries. Modern subtraction algorhythms provide an acceptable image quality; overinterpretation of stenoses and lacking information about small details is sometimes possible.

Differential Diagnosis List

Final Diagnosis

PTA and stenting under CO2 guidance

URL:	https://eurorad.org/case/675
DOI:	10.1594/EURORAD/CASE.675
ISSN:	1563-4086