Introduction
Procedural and clinical outcomes for patients referred to the cardiac catheterization laboratory, including those undergoing percutaneous structural heart interventions, depend on obtaining safe and adequate vascular access. Structural heart interventions often require percutaneous vascular access with large-bore sheaths—for example, femoral venous access for transcatheter mitral valve repair (e.g., MitraClip, Abbott Vascular, 24F) or femoral arterial access for transcatheter aortic valve replacement (TAVR, 14–18F). Although transvenous access with large-bore sheaths is required for several structural heart interventions, major vascular complications are infrequent compared with arterial procedures. Therefore, although many of the techniques described herein can be applied across any vascular access, given the morbidity and mortality related to vascular complications involving arterial procedures, this chapter will focus on arterial access.
In the early TAVR experience, vascular complications were frequent (17% of all cases) and associated with morbidity, prolonged hospitalizations, and an increased risk of death. Rates of access complication have fallen markedly, likely due to meticulous attention to location, needle cannulation and visualization of entry site, evolution in sheath technology, experience with large-bore closure techniques, and improved patient selection. However, the impact of complications when they do occur remains significant.
Most vascular complications are iliofemoral, with the major predictors being small-vessel dimensions and moderate-to-severe calcification, as well as experience of large-bore vascular access within the center performing the intervention. The miniaturization of newer devices has led to improved outcomes, with second-generation TAVR devices reported to have major vascular complications in <5% of cases. Although alternative access techniques (other than femoral) are occasionally needed (e.g., transcaval, transcarotid, or subclavian), as discussed in Chapter 12 , particularly in the setting of severe peripheral vascular disease, the transfemoral approach remains the preferred and most commonly used access for TAVR. ,
To minimize the occurrence and/or impact of vascular complications, we emphasize the need for the following:
- 1)
Prevention: procedural planning, adequate site selection, and safe vascular access using contemporary techniques
- 2)
Preparation: if complications should occur, techniques have been described to improve response
- 3)
Management: equipment available to manage complications and technical familiarity by procedural staff to manage such complications.
Preprocedural planning
For patients undergoing evaluation for TAVR, preprocedural multidetector computed tomography (MDCT) is an essential tool that provides unique insights about vascular anatomy and information about the most appropriate vascular access based on several key access-site features that should be assessed, including (1) minimal lumen diameter along the course of the intended vascular access site, (2) vascular tortuosity, (3) vascular calcification, and (4) sheath/femoral artery ratio, as well as potential issues involving the entire aorta, such as severe elongation and kinking, dissection, and/or large thrombus ( Fig. 2.1 ). ,
To maximize procedural success, these findings should preferably be reviewed and discussed by the multidisciplinary heart team or, at a minimum, be reviewed in advance with one of the operators involved in the procedure. Although MDCT is the preferred preprocedural screening imaging modality, if such is not possible or contraindicated, other imaging modalities to consider include conventional angiography or digital subtraction angiography (considered during pre-TAVR coronary angiography), magnetic resonance angiography, or intravascular ultrasound.
Transfemoral access and closure technique
Most operators favor the use of bilateral femoral arterial access for TAVR procedures. Radial access can be considered as an alternative access route for the pigtail catheter. For femoral access, we endorse the routine use of ultrasound-guided access, which has been shown to reduce the number of attempts, time to access, risk of venipuncture, and vascular complications. Techniques describing contemporary femoral arterial access, which are useful for any vascular access, especially those intended for large-bore sheaths, have been published and described here. Minimal vessel sizes required for the different TAVR sheaths are described in Table 2.1 .
| Device | Valve Size (mm) | Sheath Required | Minimal Vessel Diameter (mm) | Valve External Capsule Diameter |
|---|---|---|---|---|
| S3 | 20 | 14F expandable sheath | 5.0 | n/a |
| 23, 26 | 14F expandable sheath | 5.5 | n/a | |
| 29 | 16F expandable sheath | 6 | n/a | |
| Evolut | 23, 26, 29 | InLine sheathless 14F or 18F sheath | 5 | 6 mm/18F |
| 34 | InLine sheathless 16F or 20F sheath | 6 | 6.7 mm/20F | |
| Evolut R Pro | 23, 26, 29 | InLine sheathless 16F or 20F sheath | 6 | 6.7 mm/20F |
| Lotus | 23 | Lotus Introducer small | 6 | n/a |
| 25, 27 | Lotus Introducer large | 6.5 | n/a |
First, the lower edge of the femoral head should be identified using a hemostat or a radiopaque marker ( Fig. 2.2 ). Marking this site with a sterile marker can be useful to avoid losing the relationship with the femoral head—something that can occur when ultrasound scanning is performed. Second, subcutaneous local anesthetic is injected with or without ultrasound guidance. Third, ultrasound scanning is performed. Visualization is often best at a depth of ≈4 to 5 cm, a depth at which both the femoral artery and vein can be visualized together, with gain modified as desired until optimal visualization is obtained.
