Spiral Pseudodissection of a Tortuous Internal Mammary Artery Graft

J INVASIVE CARDIOL 2018;30(5):E37-E38.

Key words: spiral dissection, pseudodissection, internal mammary artery graft, internal mammary loop, internal mammary tortuosity

A 59-year-old man with angina despite taking  three antianginal medications was admitted for high-risk coronary intervention of an elongated and extremely tortuous left internal mammary artery (LIMA) graft to the left anterior descending (LAD) artery. LIMA had a complete 360° loop at the mid segment, followed by severe tortuosity and a subtotal occlusion at the anastomosis (Figures 1A, 1B; Videos 1, 2). This unfavorable anatomy was negotiated with a Pilot 50 guidewire (Abbott Vascular) (Figure 1C), which was exchanged through a FineCross microcatheter (Terumo) for an extra-support GrandSlam wire (Asahi Intecc), with subsequent unfolding and straightening of the LIMA’s loop (Figure 1D). This was associated with chest discomfort and electrocardiographic changes due to complete cessation of the graft’s flow. Guided by the surgical clips, a 2.5 x 12 mm everolimus-eluting stent was quickly delivered at the anastomosis, and then the FineCross was once again advanced at the distal LAD to maintain access and the GrandSlam guidewire was removed. Angiography showed partial restoration of flow, with the presence of a longitudinal filling defect along the whole length of the LIMA, indicating a possible spiral dissection (Figures 1E, 1F; Video 3). This filling defect remained unchanged after injecting 200 µg nitroglycerin in the graft, but resolved completely after advancing a BMW guidewire and removing the FineCross. Indeed, an excellent angiographic result without residual stenosis or dissection and with normal flow was confirmed after pulling the wire proximally (Figures 1G, 1H; Videos 4, 5).

The technical challenges during angioplasty of the distal anastomosis of a tortuous LIMA have been recognized. This intervention can rarely be complicated with devastating iatrogenic catheter-induced spiral dissection of the graft. Interestingly, the development of transient focal pseudolesions mimicking severe graft damage due to  unfolding of a tortuous segment of LIMA is not uncommon. However, the present erroneous angiographic appearance of a long spiral dissection across the whole length of LIMA has not been described previously. We assume this spiral pseudodissection was due to the presence of the FineCross in the LIMA along with the suboptimal graft flow due to the unfolding of the looped segment. The misdiagnosis of this effect may lead to additional balloon inflations, which could potentially be complicated with true iatrogenic dissections. Therefore, it is essential to recognize this pseudodissection in order to avoid unnecessary interventions with potential complications.

View the accompanying Video Series here.

From the ¹1st Department of Cardiology, Hippokration Hospital, National and Kapodistrian University of Athens, Athens, Greece; and ²the Department of Cardiology, Laiko Hospital, Athens, Greece.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript accepted January 16, 2018. 

Address for correspondence: Konstantinos Aznaouridis, MD, PhD, 1st Department of Cardiology, Hippokration Hospital, 114 Vas Sofias Avenue, 11527 Athens, Greece. Email: conazna@yahoo.com