Hemodialysis Access Intervention

Survival

More than one in 1000 patients in the United States now has end-stage renal disease (ESRD), and 80% of these individuals undergo hemodialysis. The overall annual mortality rate for patients on hemodialysis exceeds 20%. The mortality rate for elderly patients during the first year after initiation of dialysis is 58%. Almost 40% of patients with ESRD have concomitant coronary artery disease, and the overall annual rate of myocardial infarction for patients on hemodialysis exceeds 10%. In the hemodialysis population, the 1-year mortality rate after myocardial infarction exceeds 50%.

Hemodialysis

The number of patients with ESRD requiring renal replacement therapy (RRT) exceeded 340,000 in 2006, and by the year 2020, the number of patients with ESRD is expected to be 750,000. The United States hemodialysis program now comprises more than 6% of the entire Medicare budget. The growing prevalence of ESRD can be attributed primarily to changing demographics and the under-treatment of hypertension, diabetes, and chronic kidney disease (CKD) in the general population. Functioning hemodialysis access is critical for patients with ESRD.

Nomenclature

The selection of a surgical site for hemodialysis access is based on evidence favoring the creation of an autogenous hemodialysis access (“fistula”) whenever possible, before resorting to the creation of prosthetic arteriovenous access with polytetrafluoroethylene (PTFE) or other synthetic materials (“graft'), in compliance with the “Fistula First” policy established in the United States and in other countries. The proportion of hemodialysis patients with fistulas has been increasing in the United States. In one report, the proportion of patients on hemodialysis with autogenous fistulas increased from 48 ± 4% to 62 ± 4% between 1999 and 2007.

The identification of a specific site for permanent access creation is based on venous ( Figure 28-1 ) and arterial anatomy ( Figure 28-2 ), according to the practice favoring the nondominant arm before the dominant arm, the forearm before the upper arm, and the upper extremity before the lower extremity.

Autogenous Arteriovenous Accesses

A fistula is surgically created when a native inflow artery is directly anastomosed with a native outflow vein. A common configuration at the wrist involves an end-to-side anastomosis between the radial artery and the cephalic vein, creating the Brescia-Cimino radial-cephalic fistula ( Figure 28-3 ). Another common configuration in the upper arm entails mobilization and tunneling of the basilic vein laterally and superficially for an end-to-side anastomosis with the brachial artery, creating a transposed brachial-basilic fistula.

Prosthetic Arteriovenous Accesses

A prosthetic arteriovenous access is constructed by surgically interposing a segment of PTFE between a native artery and a native vein in either a straight or looped configuration. Loop grafts are favored over straight grafts because they increase the length of the graft amenable to needle entry. The most common graft patterns include the brachial-cephalic configuration in the forearm ( Figure 28-3 ) or the brachial-basilic configuration in the upper arm ( Figure 28-3 ).

In the forearm, the radial-cephalic autogenous access and the brachial-cephalic prosthetic access are the favored configurations ( Figure 28-3 ), with the outflow in both instances carried by the cephalic vein. This follows a medial-to-lateral course, continues along the lateral aspect of the arm, traverses the pectoral groove, and anastomoses with the axillary vein and then becomes the subclavian vein.

In the upper arm, the brachial-basilic autogenous access and the brachial-basilic prosthetic graft are common configurations, with the outflow in both instances carried by the basilic vein. This follows a lateral-to-medial course and continues in a straight line into the axillary vein, subclavian vein, and thence into the central circulation ( Figure 28-3 ). In the thigh, the superficial femoral artery-greater saphenous vein configuration is preferred, with venous outflow following a lateral-to-medial course ( Figure 28-4 ).

Anatomic Variants

A few anatomic variations are commonly encountered. Alternative patterns for prosthetic grafts include the brachial-basilic graft in the forearm that has a lateral-to-medial course, and the brachial-cephalic graft in the upper arm that has a medial-to-lateral course.

Another configuration in the forearm consists of the proximal radial artery anastomosed in a side-to-side manner with the median antebrachial vein, producing a double-outlet configuration coursing proximally and distally from the arteriovenous anastomosis. Another type of “double-outlet” access is the radial-cephalic fistula that drains into the basilic vein, a desirable variant that reduces the risk of thrombosis when one limb develops an outflow stenosis.