Use and effectiveness of Pioneer re-entry device for subintimal true lumen re-entry: single-centre data and a review of the literature

Introduction During subintimal angioplasty (SIA), it is not always possible to re-enter the vessel lumen due to a variety of factors. Recanalization using hydrophilic wires and catheters alone, apart from its potential technical failure, is also limited by minimal control over the re-entry point. This is frequently well beyond the point of occlusion, thus often compromising important collaterals. In order to bypass the obstruction and attain controlled re-entry into the lumen of the diseased vessel, a re-entry device (RED) may be required. This paper assesses our centre’s experience with the safety and efficacy of the Pioneer re-entry system and systematically reviews the pertinent literature. Method A single centre retrospective study of subintimal angioplasty involving the use of the Pioneer Plus intravascular guided reentry catheter was performed. Patient demographics including age, gender, risk factors, comorbidities clinical indication and complications were recorded. Lesion characteristics, including location and severity of calcification were also assessed. A systematic literature review of all reported studies where the Pioneer RED was used for iliac and lower limb revascularization was conducted by 2 of the authors using the PubMed (MEDLINE) and EMBASE databases. Results The study comprised 30 cases. Technical success was 97%. A small, quickly resolved extravasation was the only device related complication. These results are in line with the systematic review which identified 16 studies using the Pioneer RED, reporting a technical success rate of 87.4–100% (median = 100%) and complication rate of 0–25.8% (median = 0%). However, due to heterogeneity in definitions of technical success, data was not pooled.

FEM Simulation of Subintimal Angioplasty for the Treatment of Chronic Total Occlusions

Subintimal angioplasty is a highly challenging technique for percutaneous treatment of chronic total occlusion (CTO) in blood vessels, and the development of predictive tools for preliminary evaluation of potential outcomes and risks could be very useful for clinicians. While finite element (FE) simulation is a well-established approach to investigating partial occlusions, its extension to CTO has not been investigated yet, because of several additional issues that have to be addressed. In this work, we discuss the implementation of a FE model to simulate the main steps of the procedure, i.e., subintimal insertion of an initially folded balloon in a false lumen, inflation from eccentric position, deflation, and extraction. The model includes key morphological features of the CTO and possibility of varying spatial distribution of material properties to account for different constituents and degree of calcification. Both homogeneous and heterogeneous CTO configurations were analyzed, comparing arterial stress state, plaque compression, and postprocedural recoil. For a peak inflation pressure of 12 bar, the degree of lumen restoration was in the range 65-80%, depending on plaque heterogeneity. After balloon extraction, homogeneous highly calcified plaques exhibited substantial recovery of original shape. For homogeneous and heterogeneous CTO, values of peak von Mises stress in the arterial wall were of the same order of magnitude (range 1-1.1 MPa) but at different locations. Results compared favorably with data reported in literature for postprocedural lumen restoration and arterial stress data, confirming potential usefulness of the approach.