Title
Very Low Contrast Retrograde RCA CTO PCI in a Patient with Severe CAD and CKD
Introduction
Chronic total occlusions(CTO) remain one of the most challenging lesions to manage in percutaneous coronary intervention(PCI), especially in patients with significant comorbidities and limited renal function. Low-contrast techniques are essential to minimize the risk of contrast-induced nephropathy in patients with advanced chronic kidney disease(CKD). This case highlights a successful very low contrast retrograde RCA CTO PCI in a patient with severe coronary artery disease (CAD) and CKD stage IV.
Clinical Case
A 77-year-old male with a history of coronary artery disease(CAD) s/p LCx PCI prior, HFpEF, atrial fibrillation, CKD stage IV, hypertension, hyperlipidemia, and carotid artery disease presented with NSTEMI. A TTE showed normal left ventricular ejection fraction. Diagnostic angiography from an outside hospital revealed moderate disease in the LM and LAD arteries, severe in-stent restenosis(ISR) in the LCx, and a heavily calcified RCA CTO. IVUS (Eagle Eye) could not cross the lesion due to severe underexpansion of a prior stent (2.5 mm diameter with a proximal reference vessel size of 3.5 mm).
The patient was transferred to our facility for more advanced intervention. Initial management included diuresis and PCI of the LCx using laser atherectomy followed by intravascular lithotripsy(IVL). Laser was applied at rate/fluence 80/80, and a 3.0mm NC balloon was inflated at high pressure to pre-dilate lesion. Persistent under-expansion was noted on stent boost imaging. IVL with a 3.5mm Shockwave balloon was then used (delivered 80 pulses), improving expansion to 80%. A 3.0x38mm Synergy DES was deployed and post-dilated to 4.5mm. Selective injections with a guide extension catheter minimized contrast use, given side-hole guide catheters used. After recovery, the patient was scheduled for staged RCA CTO PCI. One week later, with a creatinine level of 4 mg/dL (at baseline), the RCA CTO PCI was performed using a very low contrast retrograde approach. Dual injections visualized a long, calcified RCA CTO with collaterals from the LAD to the PDA. Antegrade attempts with Fielder XT, Mongo, and Gaia Next 3 wires failed due to extraplaque tracking. A tip injection of a septal branch identified a tortuous connection to the PDA. After multiple retrograde wiring attempts with Sion Black, success was achieved with Suoh 3. A retrograde Mongo wire and antegrade Fielder XT were advanced, but knuckling the retrograde wire more proximally proved challenging. Hornet 14 exchanged with successful retrograde wiring into the aorta, which was then snared into guide. IVUS-guided wire positioning enabled lesion modification with IVL. Stents were placed sequentially: 2.5x48mm Synergy from distal RCA to PDA, 3.0x32mm Synergy from mid-RCA to distal RCA, and a 3.5x28mm Megatron from proximal to mid-RCA. Post-dilatation was performed, and the ostium was expanded to 6.0mm.
Discussion
This case demonstrates the importance of low-contrast PCI strategies in patients with severe CAD and CKD. Retrograde techniques, IVUS guidance, and adjunctive IVL/laser enabled effective CTO revascularization while preserving renal function. Advanced tools and techniques offer new avenues for high-risk patients traditionally deemed unsuitable for PCI.