Factors Influencing in-Stent Occlusion after Femoropopliteal Artery Stent Placement with Intravascular Ultrasound Evaluation
Can In Stent Re-Stenosis (ISR) or In Stent Occlusion (ISO) be predicted at time of stent placement?
Residual plaque after stent placement (>60% narrowing) was the most significant predictor of ISR or ISO.
Kurata N, Lida O, Asai M, Masuda M, Okamoto S, Ishihara T, Nanto K, Mano T. Factors Influencing In-Stent Occlusion after Femoropopliteal Artery Stent Placement with Intravascular Ultrasound Evaluation. J Vasc Interv Radiology. 2020. 21:213-220.
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SummaryFemoropopliteal artery lesions are commonly known to cause symptomatic presentation in patients with Peripheral Arterial Disease (PAD). Over the years, endovascular interventions of this anatomic region have surpassed surgical means as a first line (or often the only approach needed). On angiographic evaluation, patients may demonstrate plaque related stenosis or occlusions, as well as less commonly thrombosis. Plaque burden can be considered calcific or non-calcific. Evaluation of the specific underlying cause of the lesion is best confirmed with Intravascular Ultrasound (IVUS). Use of IVUS in peripheral arterial disease is operator and practice dependent. Common reasons for not using IVUS include concerns for time spent in utilization and added cost. No randomized controlled trial has been performed to date to validate outcomes bases on use of IVUS, thus utilization is again operator dependent. Interventional approached for femoropopliteal lesions include plain-old balloon angioplasty (POBA), Drug Coated Balloon angioplasty (DCB), atherectomy and Stent placement (bare metal (BMS), drug eluting stent (DES) and covered stent grafts).
In this article, the authors set out to determine if there were predictors of patients returning with In Stent Re-Stenosis (ISR) or In Stent Occlusion (ISO). This was a retrospective single center analysis of all of the patients with femoropopliteal lesions, that had utilization of IVUS pre and post stent placement. In total, 191 lesions in 162 patients were used in the analysis. Of the patients, approximately one third were Critical Limb Ischemia (CLI) patients, one third had coronary artery disease, and two thirds also had diabetes mellitus. In regard to the lesions, about 50% presented with chronic occlusions, two-thirds had calcified lesions, and the average lesion length was 17cm (+/- ~10cm). Type of stent type favored DES over BMS and Covered stent-grafts (51%/42%/6% respectively). 86% of patients had at least 1-2 vessel runoffs.
After data analysis, it was found that predictors of patients presenting with ISR or ISO were female gender, TASC II C/D, and residual plaque of >60% after stent placement. During the average total follow-up period (in clinic with duplex studies) of 19 months, there were 31% patients with ISR and 15% with ISO, with ISO patients presenting earlier than ISR patients. Patients that had less than 60% residual plaque after stenting had a 20-fold decrease in ISO.
CommentaryThe finding that residual plaque of 60% or greater was the biggest predictor of ISR and ISO in this patient population does not seem surprising. Operators commonly encounter resistant stenosis when performing angioplasty of these lesions, especially calcified plaque, which may result in higher dissections and refractory stenosis necessitating a scaffold placement. This is one of the reasons why some chose to perform atherectomy of these lesions, regardless of whether initially presenting with stenosis or occlusion. This has been evaluated in regard to vessel preparation prior to DES placement and DCB use, however currently there is an element of uncertainty as to the safety of widespread use of Paclitaxel based devices. It is also not surprising that patients with greater severity of TASC II lesions would have increased rates of significant recurrent lesions, intervening on chronic occlusions and long multifocal long segment disease can be troubling. As newer technology continues to be developed, including endovascular tacking systems, absorbable scaffolds, and newer iterations of atherectomy, it will be interesting to evaluate if these will help decrease or prolong the recurrence of the disease.
This study demonstrates use of IVUS in these interventions demonstrates a value that may be underappreciated, which is that optimal vessel debulking/prepping with atherectomy, to result in less residual plaque before stent placement, may improve patency rates. This could be better validated with a randomized trial.
Kumar Madassery, MD
Assistant Professor, Vascular & Interventional Radiology
Director, Advanced Vascular & Interventional Radiology Fellowship
Rush University Medical Center, Chicago IL
Rush Oak Park Hospital, Oak Park IL
Twitter: @kmadass, @vir_rush