Cardiac catheterization is required for many procedures such as angiography, angioplasty, valve replacement, valvuloplasty, ablation, or congenital heart repair. This process is required to assess and manage many patients presenting with myocardial infarction, heart disease, valvular disease, or congenital heart disease. Needless to say, catheterization is a heavily performed procedure in the field of interventional cardiology. A common site of entry for catheterization is the femoral artery. After catheterization procedures, appropriate mechanisms are necessary to close the port of entry of the catheter into the femoral artery. As a result, the need for devices to assist in the closure of the femoral artery is continually evolving.
Initially, the only mechanism to assist in hemostasis from the catheter insertion site would be mechanical femoral artery compression. Although mechanical compression is sufficient in patients without certain comorbidities, it can be challenging in patients who are obese and on anticoagulation therapy. In addition, patients who were managed through femoral access require a longer hospital stay, as compared to those who received radial access. Manual compression would take a longer period of time to reach hemostasis, thus increasing strain on the healthcare system. Certain procedures such as the insertion of left ventricular assist devices and mitral/aortic valve replacement procedures require relatively larger femoral vascular access sites, making mechanical compression cumbersome, or a less effective method to achieve hemostasis.
Femoral vascular closure devices can be divided into two broad categories. They can be either passive or active. Passive closure devices help with mechanical compression or by increasing thrombosis for effective hemostasis. However, passive devices do not hasten the actual time it takes to reach hemostasis. Active closure devices include suture devices, collagen plugs, and clips.
Anatomy and Physiology
The femoral artery is one of the main arteries of the lower limb. The common access site to perform a cardiac catheterization would be the common femoral artery. The common femoral artery is an extension of the external iliac artery (a terminal branch of the abdominal aorta). The inguinal ligament demarcates the start of the common femoral artery. Below the inguinal ligament, and within the femoral triangle, the femoral artery breaks into the superficial and deep femoral artery. As the superficial femoral artery makes its way within the adductor hiatus, it becomes the popliteal artery. The deep femoral artery immediately branches into the medial and lateral circumflex femoral arteries.
Within the femoral triangle, the positioning of the femoral artery around other vessels is incredibly important. From lateral to medial, these structures are the femoral nerve, femoral artery, femoral vein, femoral canal, and the deep inguinal nodes. The femoral sheath encompasses the femoral artery and the femoral vein. This spacial relationship becomes important in complications that could occur during the insertion of a femoral artery closure device.
The indication of using a femoral vascular closure device is to achieve hemostasis through successful closure of the femoral artery puncture site and to decrease the time to attaining successful hemostasis. Hemostasis for large bore access sites for structural interventions is routinely achieved using femoral vascular closure devices.
Because the majority of femoral vascular devices are evolving and data is still being gathered, many of these devices do not have strict contraindications. However, there are certain issues of concern and times when these devices are not used.
The following properties of the access site make them less suitable for the use of novel femoral vascular closure devices:
- Access obtained above the inguinal ligament
- Access obtained through the superficial or deep femoral arteries
- Access obtained from the lateral surface of the artery wall
- Multiple attempts required to obtain access site in any part of the artery
- Bacterial infection around access site
- Heavy calcification in the area of the access site
Caution should be taken during the below mentioned clinical situations:
- Anticoagulation with warfarin
- Bleeding diathesis
- Peripheral vascular disease
General equipment required for femoral artery closure device:
- Sterile gloves and sterile drapes
- Ultrasound machine
- Local anesthesia (i.e., lidocaine), syringes and needles
- 4 x 4 gauze
- Short and long J-tip wires
- Specific vascular closure devices kits
Although different closure device kits vary, the majority of kits contain the following:
- Insertion sheath
- Arteriotomy locator (modified dilator)
- 6 French or 8 French with J-tip guide wire
- Vascular closure device
Personnel necessary for the placement of a femoral vascular closure device are an interventional cardiologist, radiology technician, and nursing staff. First assistants such as physician assistants, residents, or fellows may also be present.
Necessary personnel must scrub before entering the procedure room. After donning with sterile gowns and gloves, the procedure of a catheterization can begin. Prior to the catheterization procedure, it is important to palpate the femoral pulse, and pulses at different sites of the course of the artery - such as the popliteal, tibial, and dorsalis pedis artery. The insertion of a femoral vascular closure device is done either at the beginning of the procedure (especially large bore access) or immediately after the catheterization procedure has ended. The site must be prepared appropriately with sterile drapes around the site of insertion. Ultrasound and fluoroscopic guidance may be used.
Before delving into the different types of femoral vascular closure devices, it would be pertinent to explore mechanical compression, as this method is still considered the "gold standard" for achieving hemostasis after a catheterization procedure. It is also what physicians turn to when vascular closure devices fail to deliver the appropriate response. After interventional therapeutic procedures, the removal of the sheath is delayed to allow clotting time to decrease below 180 seconds. Once the sheath is removed, firm pressure should be placed over the puncture site and slightly proximal to it for 10 minutes. A moderate amount of pressure is needed for the remaining 5 minutes. After this, a pressure dressing is applied to the site. During this time, if there is still bleeding at the site, an extra 15 minutes of pressure is required to ensure hemostasis. Following the establishment of manual compression, the patient requires at least 8 hours of bed rest to allow for adequate healing.
The technique of utilizing a femoral vascular closure device varies widely with the device used. Below are some of the devices and how they are used. As stated previously in the introduction, the types of devices can broadly be classified as passive or active.
Passive Femoral Vascular Closure Devices
A compression device can come as a device with a "C" shaped arm, which is placed on top of the access site and clamps a pad down toward the site to create manual compression. These devices serve as a substitute for mechanical compression given by healthcare workers.
Alternatively, a compression device can come with a belt and a pneumatic device. The belt goes around the patient, while the pneumatic device is placed slightly proximal to the dressing site, and pressure is applied.
Hemostatic pads are pads that are coated with a material that helps in coagulation. However, several trials show that there is no significant difference between the use of these pads as compared to mechanical compression.
Active Femoral Vascular Closure Devices
Collapsable disc with hemostatic coating: This device is inserted into the sheath already present from the catheterization, such that the tip of the device is inside the arterial lumen. After this, retraction of a segment of the device will lead to the formation of a disk at the tip, much like opening up an umbrella. Once the disk is open, the catheter can be removed. At this time, upward traction of the device is applied to ensure the disc is at the vessel wall, allowing for momentary occlusion of the puncture site. Fluoroscopy/angiography is needed at this stage to ensure that the disk (coated in radioopaque material) is against the intimal arterial wall. The steps stated until now are necessary for all the active femoral vascular closure device placements. Next, removing an outer sleeve from the device exposes surrounding subcutaneous tissue to protamine sulfate and other prothrombotic factors. The exposure of this material serves to rapidly reverse the local effects of heparin and allow for better healing. The disk is then deflated, and the device is removed. Mechanical compression is necessary for at least 5 minutes following the retraction of this device.
Collagen plug devices: Collagen plug devices follow the same procedure as stated above. However, when it comes to the unlocking and removal of the outer sleeve of the device, a collagen patch is then exposed directly within the subcutaneous tissue. The device is held in position for 30 to 45 seconds to allow for hydration of the collagen. After this, a push rod is required to separate the device from the collagen plug that is now deployed into the tissue. After applying pressure, and deflating the disk, the device can now be removed. The collagen plug remains in place and offers appropriate tissue healing and hemostasis. A second generation collagen plug device has the tip coated with polyethylene glycol. The tip lines with the outer lining of the artery helping control leakage of blood.
Polyglycolic acid device: Polyglycolic acid (PGA) device functions by deploying PGA right at the outer layer of the arterial wall.
Clip device: A clip device that follows the same technique as above. However, during deployment within the artery, two wing-like extensions branch off in opposite directions, instead of a disk. With upward traction of the device, the extensions are approximated to the puncture site. With the retraction of the device, the clips come together and draw the opposite sides of the puncture site together, approximating and closing the access site.
Suture mediated device: This device does not use an existing catheter that is in place. Suture devices are inserted directly into the site of the arteriotomy, with the help of a guidewire. A marker with pulsatile blood flow ensures that the device is in the arterial lumen. Pressing a lever at the edge of the device deploys a footplate with suture cuffs on each side, which house the suture loops. Pushing the plunger deploys the needles from the device, which pierces through the artery wall on either side of the arteriotomy site and comes in contact with the suture cuffs. Upon retraction of the needles and the device, the suture ends follow, going through the artery wall on opposite sides of the artery access site. The sutures are retrieved, tied, and pushed toward the access site.
With the growing need for catheterization procedures, it has become evident that appropriate management of the arteriotomy site has become essential. Although there are a variety of vascular closure devices that exist, as discussed in this article, it should be noted that manual compression remains the "gold standard" of treatment. Intriguingly, several studies have found that there is no overall benefit in clinical outcomes using vascular closure devices as compared to manual compression, however significant reduction in time to hemostasis and time to ambulation was noted with the use of femoral access closure devices. Therefore it is imperative for interventional cardiologists to familiarize themselves with the different types of devices that can be used and the benefits and risks of each to certain patient groups.
Enhancing Healthcare Team Outcomes
It should be noted that mechanical compression and compression devices are generally thought to be safe to use in all patient populations. They do have high hemostatic response rates, however, they require a longer time to reach hemostasis, and requiring a longer period of bed rest up to 8 hours. In patients with increased bleeding risk, femoral vascular closure devices can be considered as they provide faster time to hemostasis and have a decreased risk of bleeding/hemorrhage after device placement.[Oxford CEBM Level of Evidence 1] It should be kept in mind that the device comes with an increased risk of infection and distal ischemia. Management of these complications will likely mandate surgical repair. Active femoral vascular closure devices help in reducing time to hemostasis and decreasing the length of time needed for bed rest.[Oxford CEBM Level of Evidence 1] Suture mediated devices allow for reaccess of the same arteriotomy site in case of complications. However, collagen plugs do not allow for reaccess at the same site. Interventional cardiologists, radiology technicians, and nursing staff together form an interprofessional team for accurate deployment and post-procedural clinical monitoring. Vascular surgeons and interventional cardiologists & radiologists play an important role in the management of complications including distal dislodgement of the device, acute limb ischemia, and persistent bleeding from the vascular access site.