Subintimal recanalisation of iliac artery occlusion: CT-angio demonstration

This 80-year-old lady consulted us for a left buttock claudicatio (<100 mts). A previous CT-angiography revealed a calcific occlusion of the left common iliac artery with a good distal run-off. For this reason an endovascular recanalisation was attempted in our catheter laboratory.

Endovascular recanalisation was achieved using either a contralateral and ipsilateral approach. Negotiation of the occlusion was quite difficult and we had to do multiple attempts to advance the wire through the occlusion (Fig. 1). With the help of a snare-device the wire advanced from the contralateral approach was captured and a self-expandable stent (Luminexx-Bard 8x60 mm) was advanced from the ipsilateal access and deployed at the level of the occlusion with a good result (Fig. 1e,f). Double antiplatelet therapy was precribed for one month followed by single antiplatelet regimen. One month later the lady underwent a re-evaluation because of new symptoms on the right leg. For this reason a Colour-Doppler Ultrasound and a MDCT-angiography were done. MDCT demonstrated the absence of new lesions on both legs and clearly revealed the deployment of the stent in the subintimal space externally to the concentric calcifications of the left common iliac occlusion (Fig. 2-5).

Traditionally, aortobifemoral bypass has been the intervention of choice for iliac artery chronic total occlusions (CTOs). However, it is associated with significant morbidity and mortality, limiting its use in high-risk patients. Endovascular treatment consists of two options: PTA and selective stent placement or primary stent placement which have comparable results as stated by Klein WM et al [1]. However, many authors support that primary stent placement is indicated in total occlusions [2, 3, 4] and we agree with this approach.
To further increase the possibility of endovascular treatment, subintimal angioplasty (SIA) as proposed by Bolia for femoropopliteal CTO [5], has been extended for treating iliac artery CTOs. In the experience of Chen et al 120 patients underwent an attempted SIA of an iliac artery CTO, and 101 iliac artery CTOs were successfully treated, with a technical success rate of 84%. Technical failure was due to the inability to re-enter the lumen in all cases. This study demonstrates that SIA of iliac CTOs is feasible and can be performed safely and effectively, even in high-risk patients. Excellent patency and limb salvage rates can be achieved [6].
Also in our experience subintimal recanalisation of CTO of iliac and femoro-popliteal arteries is frequently attempted, generally not as a first choice but in most of the cases when an intraluminal crossing of the occlusion is impossible. Our experience on subintimal recanalisation is mainly focused on femoropopliteal arteries but we have done several cases of iliac artery occlusion. Effectively it is difficult to give a correct number of how many occlusions crossed are intraluminal and how many are subintimal. With the case shown here we want to underline the specific CT finding observed after treatment. In particular the axial view in Fig. 2 and 3 (movie) clearly shows the extraluminal position of the stent and the intraluminal strongly calcific occlusion of the common iliac artery. We believe that the CT finding reported here is quite original and we were not able to find other reports like this one. In the experience of Chang et al about 13 cases of heavily calcified occlusion of the iliac artery evaluated with CT in the follow-up no subintimal recanalisations were reported [7]. Only recently Ishihara et al reported a similar treatment in a case of in-stent restenosis of common iliac artery which was treated with a stent implantation outside the in-stent occlusion [8].