Lower Extremity Permanent Hemodialysis Access Placement
Paul B. Kreienberg
IndicationsMaintaining functional arteriovenous access for hemodialysis remains a continuing challenge for the access surgeon. Secondary to the improvement in the global care of the end-stage kidney disease patient, improved survival is being achieved. Patients on dialysis are living longer, and with that comes the need for more surgical access options.
There is no doubt that autogenous fistula created in the upper extremity remain the conduit of choice for arteriovenous access. In fact, once matured and usable, the radiocephalic fistula at the wrist remains the most durable form of hemodialysis access. However, as patients live longer, they will require more complex reconstructions to prolong their time on dialysis. Additionally, recent trends include increasing numbers of older patients, increased prevalence of diabetes and vascular disease, and the paradoxical increase in lifespan making all dialysis access in the upper extremities almost impossible. In general once all upper extremity access has been exhausted, lower extremity or thigh access becomes the next choice. In fact the KDOQI guidelines list the creation of thigh access as the last option.
Order of preference is as follows:
Radiocephalic fistula
Elbow brachiocephalic fistula
Transposed basilic vein
Forearm loop graft
Upper arm graft
Chest wall graft or lower extremity graft
Creation of a thigh access is always preferable to long-term catheter-based dialysis. However, often there is a reluctance to place thigh access secondary to the impression of poor performance or inordinate infection risk. Several studies have shown that the outcome of thigh grafts is similar to concurrent or historic arm grafts. As will be explained, these lower extremity access creations can be either autogenous or can be created with prosthetic materials.
With this in mind the decision to place lower extremity arteriovenous access rests on the inability to place upper extremity access.
ContraindicationsThe only absolute contraindication to placement of lower extremity arteriovenous access is the ability to place access in the upper extremities. This will be covered in the preoperative planning for patients requiring this type of access. Relative contraindications to placement of lower extremity access include body habitus and existing lower extremity bypass. In patients who are very obese, placement of lower extremity access can be quite difficult. Additionally, access for the dialysis technician may be compromised due to the patient’s pannus. The location of incisions in these patients may also predispose to higher rate of infection as occasionally the incisions will be under the pannus. Patients who have had prior lower extremity bypass have a relative contraindication to placement of lower extremity access. Certainly placement in these patients would require thorough evaluation preoperatively so as not to put the bypass at risk. Patients who have already undergone major lower extremity amputation remain excellent candidates for lower extremity access as long as inflow arteries and outflow veins remain patent.
Preoperative PlanningThree types of lower extremity access will be discussed: The saphenous vein fistula, femoral vein transposition, and femoral-based prosthetic grafts. In general the preoperative planning for all these is similar. The difference in technique and selection will be addressed among the different reconstructions.
The main factor on deciding to place lower extremity access rests on the assumption that all upper extremity options have been exhausted. Therefore, the initial evaluation should include upper extremity ultrasound to evaluate the veins in the arms and then venograms of the upper extremities to evaluate the central veins. Even if the upper arm veins are exhausted and central veins are patent and accessible, the option for a hemodialysis reliable outflow (HeRO) catheter exists obviating the need for placement of lower extremity access. This is an FDA-approved device approved for use in the upper extremities in patients with limited upper extremity outflow options. This device is a completely subcutaneously implanted device with an outflow component traversing central stenosis and arterial component similar to an upper extremity graft. The outflow component is an endoluminal, large bore; nitinol-reinforced silicone tube can be inserted via the jugular or subclavian vein to reach the atria. Preliminary data suggests that this option may have similar patency to other upper extremity grafts and superior infection rates compared to catheters.
Once the decision is made to place lower extremity access, a thorough vascular workup should commence. Our protocol is to perform pulse volume recordings of the lower extremities to assess the arterial circulation and correlate it with pulse examination. If abnormalities are identified and patients have limited options, arteriography is used liberally in these patients to assess arterial inflow and outflow to help in planning. Ultrasound evaluation of the lower extremity veins, to evaluate size, patency, duplicity, and presence of prior deep vein thrombosis is performed. If abnormalities are identified or if patients have had prior groin catheters, ascending venograms are performed.
Options for lower extremity access include the saphenous vein loop, transposed femoral vein, and prosthetic loop grafts configured between the femoral artery and veins. Patient selection for each procedure will be discussed individually.
SurgerySaphenous Vein Fistula
The saphenous vein loop is a procedure that exists for dialysis access that has many advantages and disadvantages. As opposed to other techniques discussed in this chapter,
placement of a saphenous vein loop requires a vein of at least 4 mm. It has been demonstrated that the saphenous vein once used in creation of a fistula undergoes minimal dilation. Additionally, patent inflow arteries and distal arteries make construction of this fistula possible. Basing the inflow off the more distal superficial femoral artery allows for a straighter configuration and avoids creation of the loop tunnel in the groin.
placement of a saphenous vein loop requires a vein of at least 4 mm. It has been demonstrated that the saphenous vein once used in creation of a fistula undergoes minimal dilation. Additionally, patent inflow arteries and distal arteries make construction of this fistula possible. Basing the inflow off the more distal superficial femoral artery allows for a straighter configuration and avoids creation of the loop tunnel in the groin.
Once a suitable limb is found by preoperative examination, venography, and arteriography, the patient is brought to the operating room and placed supine. General or spinal anesthesia may be used. We have found it beneficial to have the vein marked on the skin at the time of the ultrasound examination to mark the location of the vein and its major side branches. The leg is free-draped, prepped with chlorhexidine solution, and prophylactic antibiotics are administered. We use 2 g of cefazolin unless patient has a methicillin-resistant Staphylococcus aureus infection or history when 1 g of vancomycin is used. Surgery is performed using 3.5 loupe magnification and headlight illumination. After the preparation and draping, the leg is externally rotated to allow access for the incision. The incision begins proximally and the saphenous vein is exposed with care to avoid damage to the inguinal nodal packet. The proximal vein branches are ligated with 3-0 silk ties or with 6-0 or 5-0 prolene suture ligatures. The incision is extended to the level of the knee with ligation of all saphenous branches in the intervening segment. In general, this is where the vein will be the smallest and extending below this level is of no benefit. With this completed, the superficial femoral artery is exposed in the distal third of thigh. The artery is approached anterior to the sartorius muscle and proximal to the adductor canal. Once a suitable area of artery is identified, the vein is transected at the level of the knee. A Yasargil clamp or other suitable atraumatic clamp is placed on the proximal saphenous vein. We then perform controlled distention of the saphenous vein with a dextran 40 solution containing 1 unit/mL heparin. Distention of the vein is performed to 250 mm Hg by pressurizing the IV bag to that level. Once the vein is distended and pressurized, the proximal clamp is released and the vein cleared of blood. It is then reclamped and checked for leaks. These are then repaired with 6-0 prolene sutures. With the vein distended, it is then clipped distally with a hemoclip. In this way the vein remains distended for tunneling. A gentle tunnel is then created on the anterior thigh. This is done by laying the distended vein out on the anterior skin and locating the apex of the tunnel on the thigh. The tunnel should be made close to the skin (∼5 mm) to allow ease of cannulation; too deep a tunnel will render the access useless. A counter-incision is then made and the tunnel is created using a Debakey aneurysm clamp (Fig. 17.1). It is often helpful to
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