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Hemodialysis Access: Complex
Over the past decade, significant improvements have been made in quality of care and life expectancy for patients on hemodialysis. Consequently, it is not uncommon for the surgeon to be confronted with patients who have “outlived” their arteriovenous (AV) access options in the upper extremities. In one study, nearly 7% of access placements were located at a site other than the upper extremity. For many of these patients, quality of life and long-term survival depend primarily on the surgeon’s ability to provide a functional and durable AV access. To meet this challenge, the access surgeon must have a number of complex vascular access procedures in his or her surgical armamentarium and must be aware of the advantages and disadvantages of each.
What is apparent from the available literature and our own anecdotal experience is that these complex access procedures are associated with a higher complication rate compared with AV access procedures of the upper extremity, and the management of these complications is generally more challenging. Although one might be tempted to avoid complex vascular access procedures by simply placing a tunneled dialysis catheter, the significant complications associated with chronic dialysis via a catheter are well established. The Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines for vascular access recommend the use of a dialysis catheter only as a bridge to AV access placement or in patients with an extremely limited life expectancy. Despite the challenges of complex AV access placement and the associated complications, their placement is usually justified and preferable to the use of a tunneled dialysis catheter.
General Principles
In facing a complex access situation, the surgeon must obtain a complete access history and delineate the causes of prior failures. A careful investigation of the vascular anatomy is important to identify arterial or venous pathology that may affect access outcome. Although noninvasive vascular testing is useful, it may provide insufficient anatomic information on patients who have had multiple access procedures; therefore, contrast angiography and venography are often necessary. Only after a complete understanding of the history and anatomy can the surgeon consider all access options and create a long-term access strategy for the patient.
Avoiding Complex Access
As noted earlier, the complication rate of AV access procedures of the lower extremity, chest wall, and other “exotic” access sites is high, and these complications are difficult to manage. Therefore one should ensure that alternatives in the upper extremity do not exist before resorting to these locations. Even though a patient has had multiple failed AV accesses in an extremity, a venogram may reveal an alternative vein, such as a paired brachial vein or a patent cephalic vein in the deltopectoral groove that can provide venous outflow for an additional access procedure in the extremity. Such options should be used before moving to sites outside the upper extremity ( Fig. 175.1 ). If a central venous stenosis is present and the vessels in the upper extremity appear adequate for AV access placement, the surgeon should consider angioplasty and/or stenting of the central vein stenosis and then placement of an upper extremity access rather than proceeding with a complex access elsewhere. Although the primary patency of percutaneous central vein angioplasty is only 29% at 12 months, remedial angioplasty procedures either alone or with a stent are generally easy to perform and can extend the 12-month patency to more than 70% ( Fig. 175.2 ). Now with the availability of hybrid access devices such as the HeRO and innovative techniques such as the “inside-out” (discussed later), central venous occlusion can often be treated successfully and prolong upper extremity access.
Selection of a Complex Access Site
Although algorithms have been developed that define a general order of preference for “routine” access placement in the upper extremity, the development of a similar algorithm for “complex” access placement is problematic, given the dearth of evidence-based literature related to these procedures. It is possible, however, to provide broad recommendations regarding the clinical situations in which a particular complex AV access procedure is most helpful and those in which it should be avoided. These recommendations are outlined in Table 175.1 . Some have even proposed a classification system to describe options available and report causes of failure to standardize terminology when discussing these difficult patients.
TABLE 175.1
Major Complex Access Procedures: Indications, Relative Contraindications, and Anatomic Requirements
| Access Procedure | Specific Anatomic Requirements | Ideal Clinical Situation | Relative Contraindications |
|---|---|---|---|
| Autogenous femoral vein transposition | Patent femoral vein >3 mm in diameter Patent, noncalcified superficial femoropopliteal artery |
Pediatric or young, healthy patients Patients who are hypercoagulable with no other autogenous access options Patients at high risk for infection (poor hygiene, immunosuppressed, multiple previous access infections) |
Significant obesity of the thigh Patients who are elderly or “medically fragile” Access sites for temporary catheter placement not readily available Patients with symptomatic PAD |
| Prosthetic mid-thigh loop femoral–femoral access Prosthetic loop femoral–femoral access |
Patent femoral or common femoral vein Patent, noncalcified superficial femoral artery (mid-thigh access) or common femoral artery |
Patients who are elderly or have significant medical comorbidities | Patients at high risk for infection (poor hygiene, immunosuppressed, multiple previous access infections) Patients who are morbidly obese Patients with symptomatic PAD |
| Prosthetic chest wall access | Patent axillosubclavian artery and vein Patent central vein |
Patients who are morbidly obese Patients at high risk for access-related limb ischemia |
Patients who are reasonable candidates for autogenous or prosthetic thigh access procedures |
| Tunneled dialysis catheter | Patent central vein | Patients who are “medically fragile” or have limited life expectancy (<6 months) Patients in whom all alternative access procedures have been expended |
Patients who are candidates for an alternative complex access procedure (autogenous or prosthetic thigh or chest wall access) |
| Hemoaccess Reliable Outflow vascular access device | Guide wire access to a patent central vein Brachial artery >3 mm |
A central venous stenosis/occlusion that precludes upper extremity autogenous or prosthetic access options Patients otherwise relegated to dialysis via a tunneled dialysis catheter |
Active infection Systolic blood pressure <100 mm Hg Ejection fraction <20% |
Autogenous Arteriovenous Access
Several techniques have been described that use the saphenous and femoral veins to create autogenous AV accesses in the upper and lower extremities. These veins can be completely mobilized and disconnected both proximally and distally to create an access at a site remote from their origin (translocation). Alternatively, the distal portion of the vein can be mobilized and tunneled superficially, leaving the central portion of the vein connected to its normal anatomic position (transposition).
Given the high infection rate associated with AV access procedures of the lower extremity, use of the saphenous vein or femoral vein translocation or transposition procedures in the thigh is theoretically appealing. However, these operations have been associated with wound complications related to vein harvest and access-related ischemia or steal syndrome; therefore, their role in AV access procedures remains undefined, and they are not included in the KDOQI clinical practice guidelines.
Translocation Procedures
The autogenous brachial artery–axillary vein fistula with saphenous vein or femoropopliteal vein translocation is an alternative to thigh access for patients with poor superficial upper extremity veins who are not candidates for a traditional upper extremity autogenous access. This access may also be indicated for patients with multiple failed upper extremity prosthetic AV accesses owing to infection or unexplained thrombosis.
Saphenous Vein–Forearm Translocation
Few studies have been published evaluating saphenous vein–forearm translocation for hemodialysis access. Secondary patency rates vary widely between the studies from 50% to 96% at 1 year. The saphenous vein can be translocated as a forearm loop configuration or placed in a straight configuration from the radial artery to the antecubital vein.
Femoropopliteal Vein–Arm Translocation
Results
Huber et al. reported a series of 30 patients who underwent translocated femoral vein–upper arm brachial axillary access. They reported primary and secondary patency rates of 67% and 100% at 18 months. Although this procedure has the potential advantages of an autogenous access, they must be balanced against a higher incidence of wound hematomas, compartment syndrome, and access-related upper extremity ischemia ( Table 175.2 ). ,
TABLE 175.2
Results of Complex Thigh and Upper Extremity Accesses
| Access Type/Series | Configuration | Number of Accesses | Secondary Patency (%) | Infection (%) | Wound Complications (%) | Access-Related Ischemia (%) | |
|---|---|---|---|---|---|---|---|
| 1-Year | 2-Year | ||||||
| Prosthetic Thigh | |||||||
| Cull et al. | PTL | 116 | 68 | 54 | 41 | — | 11 |
| Taylor et al. | PTL | 45 | 52 | 47 | 11 | — | 16 |
| Bhandari et al. | PTL | 49 | 85 | 82 | 35 | — | 0 |
| Vogel et al. | PTL | 126 | 62 | — | 20 | — | 0 |
| Korzets et al. | PTL | 37 | 73 | 65 | 11 | — | 11 |
| Englesbe et al. | PTL | 30 | 41 | 26 | 27 | — | 3 |
| Khadra et al. | PTL | 74 | 74 | 63 | 16 | — | 3 |
| Tashjian et al. | PTL | 73 | 83 | 83 | 22 | — | 2 |
| Flarup et al. | MTL | 14 | 64 | 18 | 21 | — | 0 |
| Scott et al. | MTL | 46 | 68 | 43 | 21 | — | 13 |
| Autogenous Thigh | |||||||
| Gradman et al. | FV transposition | 25 | 87 | 87 | 0 | 28 | 32 |
| Gradman et al. | FV transposition | 22 | 100 | 94 | 0 | 0 | 0 |
| Autogenous Upper Extremity | |||||||
| Huber et al. | BA-Ax FV translocation | 30 | 100 | 100 | 0 | 40 | 27 |
| Elwakeel et al. | BA-BV transposition | 21 | 76 | 55 | 5 | 0 | 0 |
| Angle et al. | BA-BV transposition | 20 | — | — | — | — | 0 |
| Casey et al. | BA-BV transposition | 17 | 40 | 40 | — | — | — |
Ax , axillary vein; BA , brachial artery; BV , brachial vein; FV , femoral vein; MTL , mid-thigh loop; PTL , proximal thigh loop.
Arm composite autogenous vascular access (ACAVA) using the great saphenous vein and the femoral vein has also been described. The rationale for this technique was to decrease the diameter of the vein at the arterial anastomosis in hopes to minimize the rate of steal syndrome. At 12 months, the secondary patency rate was 81%. Of note, one patient developed steal syndrome.
Technique
Duplex ultrasonography of the lower extremity is necessary to confirm that the femoral vein is patent and has an adequate diameter (>6 mm). To expose the femoral vein, an incision is made in the groin and extended distally along the medial border of the sartorius muscle. The vein is mobilized from the mid-popliteal fossa to the common femoral vein. It is important to preserve the profunda vein to reduce the symptoms related to outflow obstruction. The reversed vein is connected to the brachial artery and axillary vein ( Fig. 175.3 ).
Transposition Procedures
Brachial Vein Transposition
Results
In 2004, Bazan and Schanzer reported two cases of autogenous brachial vein transposition in patients with inadequate superficial upper extremity veins. After 1 year, both accesses were functional. Other series report secondary patency rates from 40% to 92% at 1 year. This procedure can be done as a single stage transposition or with a two-stage technique. One published series reported a 2-year patency of 55%.
Technique
We recommend that brachial vein transposition be performed as a two-stage procedure. One-stage procedures are considered only in cases in which the brachial vein exceeds 4 mm in diameter. The brachial artery and vein are exposed in the antecubital fossa. The brachial vein is connected to the proximal radial or brachial artery. The second stage is performed 4 to 6 weeks later to allow the vein wall to arterialize, thereby facilitating its mobilization. Care should be taken to avoid injury to medial antebrachial cutaneous and median nerves while the brachial vein is completely mobilized. Venous tributaries are individually suture-ligated. The vein is divided near the AV anastomosis and passed through a subcutaneous tunnel. An end-to-end anastomosis of the vein is then performed.
Saphenous Vein Transposition
The common femoral artery–saphenous vein loop transposition was first described in a single patient by May et al. in 1969. Based on the limited number of series reporting the outcome of saphenous vein translocation, the following conclusions can be drawn: (1) the use of skip incisions or endoscopic techniques to harvest the saphenous vein may decrease the rate of wound complications associated with this procedure; (2) because the great saphenous vein does not readily dilate after access creation, only veins greater than 3 mm in diameter should be used and the vein must be tunneled just beneath the dermis to allow reliable cannulation of the access; (3) cannulation of the access must be delayed at least 6 weeks postoperatively to prevent puncture-site bleeding and hematoma; (4) the procedure may not be practical for patients who are morbidly obese or those with a large redundant pannus because access cannulation may require the patient to lie in the supine position and retract the pannus to expose the access.
Alomran et al. described an innovation of the GSV AVF in the form of a semipaneled graft, which aims to overcome the poor dilation of the GSV but requires harvest of its entire length. This technique is labor-intensive because it involves longitudinal venotomy and open valvulotomy of the entire GSV and the creation of panels.
Technique
The saphenous vein is exposed and mobilized from the saphenofemoral junction to the knee. The saphenous vein is transected distally at the knee, leaving the saphenofemoral junction intact. The vein is then tunneled to form a subcutaneous loop and anastomosed to the proximal superficial femoral artery.
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