Transfemoral transcatheter aortic valve implantation in patients with small diseased peripheral vessels

Abstract

Objectives

The aim of this study was to assess the feasibility, safety and short-term outcomes of transfemoral transcatheter aortic valve implantation (TF-TAVI) in patients with small diseased peripheral vessels.

Background

The transfemoral (TF) route for transcatheter aortic valve (TAVI) is the default option due to associated advantages. However, this is limited due to the high prevalence of significant peripheral arterial disease and increased risk of vascular complications.

Methods

Of 539 consecutive patients undergoing TAVI in a single Italian center, 23 patients underwent TF-TAVI in the presence of small peripheral vessels as defined by a minimal luminal diameter (MLD) of ≤ 5.5 mm [by computed tomography (CT)] and/or the inability to advance a large-bore sheath. Calcification was defined as being concentric if calcium extended more than 270° around the circumference of the artery. All patients underwent 30-day clinical follow-up.

Results

17 (73.9%) patients underwent peripheral vessel pre-dilatation with a semi-compliant balloon and 6 (26.1%) patients with a Solopath sheath. 6 (26.1%) patients suffered a peri-procedural complication, with 1 patient requiring surgical embolectomy for thrombotic occlusion and the remaining patients successfully managed percutaneously in the catheter laboratory. No patient suffered a vessel perforation or required implantation of a covered stent. At 30-day follow-up, all patients were free of symptoms and signs or symptoms of peripheral vascular disease, with well-functioning TAVI prostheses as evaluated by echocardiography.

Conclusions

Performing TF-TAVI is feasible in patients with no other viable vascular access option in the presence of small MLD and calcification of the peripheral vasculature, with any anticipated acute vascular complication managed in the catheter laboratory with established percutaneous techniques.

Highlights

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Small peripheral vessels is regarded as contraindication to transfemoral TAVI.
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Transfemoral TAVI is associated with better clinical outcomes when compared with other access routes.
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Transfemoral delivery is feasible in these patients accepting a higher vascular complication rate.
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With complimentary peripheral interventional techniques, complications can be successfully managed.

1 Introduction

Transcatheter aortic valve implantation (TAVI) is now the established treatment strategy for high-risk patients presenting with symptomatic aortic stenosis (AS) . While there are a number of different possible access sites, the transfemoral (TF) route has become the default strategy due to a number of advantages including shorter procedure and recovery times , less post-procedural pain , and the ability to perform the procedure under conscious sedation . TF-TAVI has also been shown to be associated with improved outcomes when compared to other access sites, likely reflecting the higher-risk patient cohort in whom peripheral access is not deemed suitable .

The most frequent complication occurring during TF-TAVI are peripheral vascular complications related to the access site and major vascular complications are associated with negative clinical outcomes . Implantation of first generation TF devices was limited by the size of the peripheral vasculature with minimal luminal diameters (MLD) of 8.4 mm [22 French (Fr) and 9.2 mm (24 Fr) required respectively]. Indeed in some centers, surgical cut-down was routinely performed to ensure optimal vessel closure under direct vision following sheath removal. In recent years, there has been rapid evolution of TAVI prostheses and delivery systems with current devices requiring a MLD of 5.5 mm, which has also enabled the procedure to become completely percutaneous . Further strategies including the ‘cross-over’ technique whereby a wire is placed in the femoral artery that is used for TAVI access has also reduced the likelihood of uncontrollable peripheral vascular complications .

As a result of these improvements, a significant minority of patients remain who present with peripheral vessels that have dimensions that are smaller than the recommended MLD of 6 mm with current delivery sheaths. These patients often have many associated co-morbidities, are of higher surgical risk , and are subsequently subjected to more invasive surgical access options (requiring general anaesthesia and intubation) or no procedure at all which is associated with very poor prognosis and 50% mortality at 2 years .

Therefore, the possibility of performing TF-TAVI in these highest risk patients, who have most to benefit, is very attractive. We describe our experience of performing TF-TAVI in patients with small peripheral vessels with regards to safety, feasibility and short-term outcomes.

2 Materials and methods

All patients were assessed by a dedicated multidisciplinary Heart Team and were considered suitable for TAVI if they were deemed inoperable or of high surgical risk. The choice of valve prosthesis was determined by patient specific factors, including aortic annulus size, annular shape, presence and distribution of calcium, coronary ostial height and aortic angulation. Device success was defined as deployment of the device in the correct anatomical position without associated more-than-mild aortic regurgitation with successful retrieval of the delivery system.

Between January 2011 and October 2014, the procedural details of all patients that underwent TAVI at the San Raffaele Scientific Institute, Milan, Italy were analyzed. During this period, 432 patients underwent TF-TAVI with current generation TAVI devices [Corevalve (Medtronic, Minneapolis, USA), Sapien XT (Edwards LifeSciences, Irvine, CA, USA), Lotus valve (Boston Scientific, Natick, MA, USA) and Direct flow (Direct Flow medical, Santa Rosa, CA, USA)] and 107 patients underwent TAVI via alternate vascular access routes.

All computed tomography (CT) studies were independently analyzed by two independent assessors with OsiriX software with measurements made in at least two different planes and was used to assess vessel size as well as the presence and distribution of calcification. Small peripheral vessels were defined as an MLA of < 5.5 mm bilaterally in the femoral or common iliac arteries (as measured by CT) and/or inability to advance the large-bore TAVI sheath.

For the assessment of calcification, a cut-off of 200 Hounsfield units was used. The peripheral vasculature was divided into three segments (common iliac artery, external iliac artery and common femoral artery) and in each the vessel calcification was defined as being concentric if calcium extended more than 270° around the circumference of the artery. Thus, the location and the presence (or absence) of calcium were recorded dichotomously.

All patients underwent a TF procedure on the side of the larger vessel diameter. The ‘cross-over technique’ was employed, with a wire placed via the contralateral femoral artery or radial artery in the side of intervention to enable the establishment of hemostasis upon removal of the sheath or in the event of vessel injury . To facilitate passage of the delivery system, two approaches were used. Either pre-dilatation with a 8×40 mm semi-compliant balloon was carried out ( Fig. 1 ) or pre-dilatation was peformed with the use of the balloon expandable Solopath® sheath (Terumo, Somerset, NJ, USA) ( Fig. 2 ). The Solopath® sheath has an insertion profile of 15 French (Fr) surrounded by a balloon that is inflated resulting in radial expansion of the sheath (and therefore the peripheral artery) resulting in a final inner diameter of 18 Fr facilitating passage of a TAVI delivery system.

Following removal of the sheath, the peripheral access site was closed percutaneously with either one Prostar XL (Abbott Vascular, Santa Clara, CA, USA) or two ProGlide (Abbott Vascular) vascular closure devices.

All patients were assessed with regards to peri-procedural peripheral vascular complications, at hospital discharge, at 30-days and at 6 months. All patients provided written informed consent for both the procedure and subsequent data collection and analysis.

Continuous variables are presented as the mean ± standard deviation (SD). Normality of each continuous variable was tested with the Kolmogorov–Smirnov test. Differences in continuous variables between groups were compared using the Student t-test. Categorical variables are presented as numerical values and percentages and were compared using the Fisher’s exact test. All reported p values are 2-sided and values of p < 0.05 were regarded as statistically significant. Analyses were performed with SPSS version 21.0 (SPSS Inc., Chicago IL, USA).