Other Access

Anatomy

While access sites such as the common femoral artery are easily accessible, sometimes alternative access may be needed as a result of the previous site being infected, scarred, or occluded. Preoperative planning by considering the patient’s anatomy, vessel to be accessed, location of intended treatment, positioning of the patient for comfort, and devices needed for treatment is paramount in making the procedure safe and efficient.

Depending on the area of access and body habitus, patients may need further adjustments or retraction of extra tissue, which can be done with tape. Full exposure of the site allows the clinician the ease of access and control.

For patients with heavily scarred access sites, a small incision at the area of access may help advance the sheath through scar tissue. The use of serial dilation is also helpful. In addition, the use of stiffer wires such as Amplatz or Rosen can help with trackability and ability to push forward.

The anatomy of the access site should also be taken into consideration. The diameter of the access vessel will determine the maximum size of sheath that can be placed ( Table 2.1 ). This will in effect determine which device can be delivered through the sheath. Vessel tortuosity can affect the placement of the sheath. It may preclude the full advancement of the sheath or the ability of the device to be able to navigate the curves and turns. If the vessel is very tortuous, use of a stiffer system (wire, guide catheter. and/or sheath) or an alternative access site should be considered.

Pathology

Within the vessel, if the area of desired access is heavily calcified or has significant atherosclerotic plaque, it is difficult and potentially dangerous to insert a sheath through this area. It can cause rupture, dissection, thrombosis, or distal embolization. Preferably, a different access site that does not include the area of stenosis or occlusion should be chosen. If the lesion is not precisely at the access site, adjuncts such as balloon angioplasty with or without stenting can be used to allow the passage of the sheaths through the stenotic vascular segments.

Location

The location of the intended treatment area will help determine the possible access sites. A shorter working distance from the access site to the treatment site is favorable because of better deliverability, trackability, and torque ability. For longer distances, it may be difficult to navigate devices to the location of interest and to maintain enough support in the system to be able to perform the planned interventions. For access sites in the lower extremity, a lesion at the mid superficial artery or popliteal artery can be potentially accessed from the contralateral common femoral artery, the ipsilateral common femoral artery, pedal access, or brachial access. Brachial access is unlikely to reach tibial or pedal arteries. Patients are supine for most procedures, but popliteal access requires preferentially a prone position or, less frequently, supine position with flexion and external rotation of the leg. Brachial access requires the patient’s arm to be supinated and can be extended or abducted if needed ( Table 2.2 ).