J INVASIVE CARDIOL 2018;30(7):E57-E58.
Key words: left main dissection, mother-and-child catheter, optical coherence tomography
A 54-year-old man presented with non-ST elevation myocardial infarction. Coronary angiogram showed two-vessel disease with severe stenosis in the mid left anterior descending (LAD) artery and proximal and distal left circumflex (LCX) artery (Figure 1). Percutaneous coronary intervention (PCI) to the LCX was performed under optical coherence tomography (OCT) guidance. A 3 x 40 mm drug-eluting stent (DES) was implanted in the LCX, but landed more proximally than intended due to breathing motion. As a result, there was gross malapposition of the proximal stent as shown by OCT (Figure 2). To facilitate delivery of a 4 mm non-compliant balloon across the malapposed stent, a 6 Fr GuideLiner “child” support catheter (Vascular Solutions) was inserted into the existing “mother” 6 Fr guiding catheter to provide extra coaxial back-up support. OCT imaging of the LCX after stent postdilation was suboptimal due to preferential contrast flow into the large LAD. Therefore, the soft GuideLiner tip was advanced into the proximal LCX to provide selective contrast injection to enhance OCT imaging. Our practice routinely uses very-short hand injection of 10-12 mL contrast for OCT image acquisition.
Angiography after OCT acquisition showed hydraulic spiral dissection from the proximal LCX extending retrograde into the proximal LAD and distal left main (LM) stem (Figures 3 and 4; Video 2). A 4.0 mm semicompliant (SC) balloon was immediately inflated at the LCX dissection site for 1 minute. Subsequent angiogram with balloon occlusion of the LCX showed patent LAD with no contrast staining (Figure 5). A 4 x 24 mm DES was implanted from the LM into the LCX, overlapping the initial LCX stent. The final angiogram was satisfactory and the patient remained stable throughout the procedure.
Mother-and-child catheter pairing the GuideLiner support catheter delivered through a standard guiding catheter permits deep intubation of the target vessel to provide coaxial back-up support to facilitate stent delivery across heavily calcified lesions in tortuous vessels and selective contrast injection. In this case, the soft tip of the GuideLiner was not coaxial to the tortuous LCX and likely abutted the vessel wall or plaque despite no warning of pressure damping before contrast injection during OCT acquisition. Focal hydraulic pressure generated by short and forceful hand contrast injection could easily create a crack at a vulnerable plaque and track into the injury point, resulting in coronary dissection. Therefore, positioning of the GuideLiner for OCT acquisition in tortuous vessels requires special attention to avoid iatrogenic dissection.
View the accompanying Video Series here.
From the Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People’s Republic of China.
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.
Address for correspondence: Dr Wai Kin Chi, Division of Cardiology, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, 9/F Clinical Science Building, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong SAR, China. Email: firstname.lastname@example.org