227 227 Stone PH, Saito S, Takahashi S, et al. Prediction of progression of coronary artery disease and clinical outcomes using vascular profiling of endothelial shear stress and arterial plaque characteristics: the PREDICTION Study. Circulation. 2012; 126:172–81.
228 228 Samady H, Eshtehardi P, McDaniel MC, Coronary artery wall shear stress is associated with progression and transformation of atherosclerotic plaque and arterial remodeling in patients with coronary artery disease. Circulation. 2011; 124:779–88.
229 229 Gijsen FJ, Wentzel JJ, Thury A, et al. Strain distribution over plaques in human coronary arteries relates to shear stress. Am J Physiol Heart Circ Physiol. 2008; 295:H1608–14.
CHAPTER 2
The Essentials of Femoral Vascular Access and Closure
Francesco Meucci, Miroslava Stolcova, Flavia Caniato, Mohammad Sarraf, Alessio Mattesini, and Carlo Di Mario
While we are often preoccupied with the coronary and cardiac complications of catheterization and intervention, it is femoral access complications that occur more frequently, and which are certainly more recognized and remembered by patients. The incidence of local vascular complications that are considered major, as defined by the need for prolonged hospitalization, transfusion, or vascular surgery, ranges between 1% and 1.5% in diagnostic catheterization procedures, and typically between 3% and 5% in interventional procedures. More recently, refinements in techniques and antithrombotic regimes have reduced femoral vascular complications in interventional procedures to 2–3%, but they still remain frequent adverse events [1–3]. Risk factors for vascular complications include advanced age, female gender, low body surface area (BSA), aggressive antithrombin or antiplatelet agent use (e.g. GP IIb/IIIa inhibitors), emergent procedures, vascular disease, vessel size, sheath size, and puncture location [1,4]. The subjects of femoral access and management of femoral puncture after sheath removal are of vital importance in cardiac catheterizations and interventions, especially in patients with high risk of complications.
Femoral access
Anatomy
A good understanding of some key features of the local anatomy is essential for both optimal access and ideal management of the puncture site. Careful attention to access and careful evaluation of the access site are fundamental to reduce sheath insertion trauma and lead to uncomplicated sheath removal and the safe use of vascular closure devices.
It is important to puncture at the level of the common femoral artery. This allows compression of the vessel against the femoral head at the time of sheath removal. Punctures below the common femoral arterial bifurcation (hence in the profunda femoris or the superficial femoral artery) are over soft tissue and are difficult to compress (Figures 2.1 and 2.2). Such punctures have been shown to be associated with increased risk of pseudoaneurysms and arteriovenous fistula formation [5,6]. Punctures above the inguinal ligament (hence in the external iliac artery) are in the retroperitoneal space which also represents an incompressible space. Such high punctures are associated with increased risk of retroperitoneal bleeding [6–8].
Figure 2.1 Femoral artery angiogram taken after sheath insertion. The sheath has been inserted into the superficial femoral artery (SFA). The profunda femoris or deep femoral artery is labeled PF. The sheath terminates in the common femoral artery (CFA). The arrow denotes the lower margin of the curve of the deep circumflex iliac artery. This lower border of the curve courses along the inguinal ligament. Punctures above this landmark are usually adjacent to the retroperitoneal space and poses a high risk for bleeding complications.
Figure 2.2 Bilateral femoral artery angiograms. On the left panel, a line is drawn through the level of the mid femoral head. This is normally an ideal location for puncture. In this case, however, the femoral artery bifurcation is above the mid femoral head and the sheath can be seen entering the deep femoral artery. The right panel shows the left femoral angiogram. A line is drawn at the level of the top of the femoral head, showing a remarkably high bifurcation in this patient. Even though the sheath insertion on this side is just below the top of the femoral head, it is also in the deep femoral artery. Although this puncture is compressible over the femoral head, the branch is relatively smaller than the common femoral artery and less well suited for use of closure devices.
Landmarks on fluoroscopy are useful for identifying the position of the common femoral artery. About 75–80% of the common femoral bifurcation is at or below the inferior border of the femoral head and 95% is at or below the mid femoral head [5,9]. While the inguinal ligament is not visualized under fluoroscopy, the deep circumflex iliac artery is commonly used as a surrogate marker of the upper border of the common femoral artery because it is the last arterial branch of the external iliac artery before the external iliac courses under the inguinal ligament and becomes the common femoral artery (Figure 2.1). The deep circumflex iliac artery arises from the lateral aspect of the external iliac artery nearly opposite the origin of the inferior epigastric artery. It ascends obliquely laterally behind the inguinal ligament, contained in a fibrous sheath formed by the junction of the transversalis fascia and iliac fascia, to the anterior superior iliac spine. Puncture above the most inferior border of the course of the deep circumflex iliac artery has been associated with increased risk of retroperitoneal hemorrhage. This landmark is above the most superior border of the acetabulum in most patients [6].
Puncture technique
The basic technique of arterial access has changed very little since it was initially introduced by Seldinger [10]. Puncture of the common femoral artery is basically unchanged, save that the original concept used a through and through puncture and withdrawal of needle into the arterial lumen, while our current approach ideally punctures only the anterior surface of the femoral artery.
However, the technique can be substantially improved by using fluoroscopy of bony landmarks to identify the likely course of the common femoral artery followed by confirmation with femoral angiography after sheath insertion [11]. A point of entry into the common femoral artery at the mid femoral head or slightly above is ideal. The femoral skin crease, which is a very commonly used landmark for puncture, is distal to the common femoral bifurcation in 72% of cases [12]. Generally speaking, younger patients have a mid‐femoral head location relatively close or slightly above the femoral crease. Older patients have a femoral head significantly above the femoral crease, since the crease tends to sag with age. Obese patients may have two or sometimes even three femoral creases.
The technique of puncture requires multiple small steps to be optimized. Before local anesthesia is given, a clamp or needle can be laid at the point where the pulse is most easily felt, just above the femoral crease. Fluoroscopy can be used to locate the position of the needle relative to the center of the femoral head (Figure 2.3). Local anesthesia can thus be given accordingly. The needle should be aimed towards the artery at an angle of approximately 45o, avoiding too vertical or acute angles between the needle and the skin plane that can create too vertical or too long paths within the