Salvage of Chronic Total Occlusion Caused by Inadvertent False Lumen Stent Implantation After Iatrogenic Coronary Artery Dissection: Stenting the “TRALSE” Lumen

Title: Salvage of chronic total occlusion caused by inadvertent false lumen stent implantation after iatrogenic coronary artery dissection: Stenting the “TRALSE” lumen. Introduction: Iatrogenic coronary artery dissection is a known complication of percutaneous coronary intervention (PCI) and is very challenging to manage which may lead to inadvertent stenting of the false lumen causing chronic total occlusions (CTO). We present an alternative technique in the management of CTO caused by false lumen stenting. Clinical Case: A 47-year-old man, with chronic stable angina and inferior wall stress induced ischemia had PCI in another institution for CTO of the ostioproximal right posterior descending artery (RPDA). An iatrogenic long-segment coronary artery dissection of the right coronary artery (RCA) was noted with residual dye stasis and TIMI 2 flow at the distal RCA segments despite deploying drug-eluting stents (DES) at the ostioproximal to mid RCA and distal RCA to ostioproximal RPDA. Repeat treadmill exercise test after 14 months was still abnormal and repeat angiogram showed a falsely stented proximal to mid RCA and distal RCA to RPDA with CTO of the distal RCA but with transapical epicardial collaterals from the LAD to the RPDA. Bilateral femoral access using 7F sheaths was done, with cannulation of the left and right coronary ostia using 7F AL 0.75 and a 7F JR4 guiding catheters respectively. A Finecross microcatheter with a Fielder XTA guidewire via the JR4 was maneuvered distally to the RPDA in the proximal cap of the stented false lumen for reference. A retrograde approach via the AL 0.75 crossing the LAD to RPDA collaterals was done using another Finecross microcatheter with a Fielder FC guidewire. A Gaia second guidewire was then exchanged and was able to cross the distal cap of the CTO RPDA and maneuvered towards the reference guidewire creating a communication between the distal true lumen and the proximal stented false lumen, so called “tralse” lumen. After wire externalization and balloon dilation, intravascular ultrasound (IVUS) confirmed the presence of a compressed non-functional true lumen and under-expanded false lumen stents at the proximal to mid segment. Salvage of the falsely stented segments were done by multiple sequential balloon dilatations further increasing lumen area facilitating stenting the “tralse” lumen using the following DES: Ultimaster 4.0 x 15 mm, Ultimaster 2.75 x 33 mm, and Ultimaster 2.75 x 18 mm. Final IVUS run showed well apposed and expanded stents, and final angiogram showed <10% residual stenosis with TIMI 3 flow, MBG 3. After a month, the patient was asymptomatic and repeat treadmill exercise test showed normal results with resolution of stress induced inferior wall ischemia. Discussion: There are few reported cases on how to manage CTO caused by false lumen stenting and this approach offers an effective alternative technique especially if there is significant compression of the proximal true lumen rendering it non-functional. This case also highlights the importance of IVUS in both diagnosis and PCI guidance including its advantage over other imaging modalities.