The Role of Routine Venography Prior to Fistula Creation

Fig. 14.1

Central occlusion. This right upper extremity venogram shows an occlusion of the right subclavian vein. (A) This is likely related to previous placement of a temporary hemodialysis catheter in the right subclavian vein. Contrast is draining into the superior vena cava (B) via numerous well-formed collaterals (C)

Fig. 14.2

(a) A left upper extremity venogram shows the forearm cephalic (FC) and forearm brachial (FB) veins drain via the median cubital vein (MC). The FC vein in this patient is suitable for use in creation of a radiocephalic AV fistula. (b) The median cubital vein (MC) drains into the basilic (BV) and cephalic (CV) veins of the upper arm. (c) The basilic vein (BV), axillary vein (AV), cephalic vein (CV), and subclavian vein (SCV) join the internal jugular vein to form the brachiocephalic vein (BCV) which drains into the superior vena cava

Fig. 14.3

A left upper extremity venogram shows a diminutive upper arm cephalic (UC) and a suitable upper arm basilic (UB) vein. This patient underwent a left upper arm brachiobasilic arteriovenous fistula creation

Fig. 14.4

A right upper extremity venogram shows absent superficial basilic and cephalic veins. This patient underwent a right upper arm arteriovenous graft placement

Contrast Selection

The choice of contrast is an important consideration, particularly in patients with renal impairment. Iodine-based contrast agents are the mainstay of vascular imaging, but they carry with them the risk of contrast-induced nephropathy (CIN). CIN has been defined as an increase in serum creatinine of greater than 25 % or absolute increase of 0.5 mg/dL after contrast administration [10]. While the acute renal failure induced by contrast can lead to the need for renal replacement therapy, the importance of CIN, as demonstrated by several longitudinal studies, is an increase in all-cause mortality [24, 26]. Further, CIN almost exclusively occurs in patients with already depressed renal function, particularly those with advanced renal disease, such as those presenting for venography prior to fistula creation (Heye 2006 Radiology). Ideally, patients are evaluated and fistulae created at least 6 months prior to their anticipated need for hemodialysis in order to allow for maturation of AVF. This targeted subset of patients are at greatest risk for CIN.

An alternative to conventional contrast-enhanced venography is carbon-dioxide (CO₂) venography, which is 97 % specific and 85 % sensitive in assessing upper limb vein patency and stenosis [22]. Heye et al. reported successful AVF access creation in 77 % of patients without suitable veins on physical examination after preoperative venous mapping with CO₂ venography [23]. Twenty percent of these AVFs were radiocephalic AVFs, which correlated well with similar studies using iodinated contrast and Vasc Surg.

Newer, less nephrotoxic, contrast agents have now replaced the tri-iodinated, high-osmolar contrast that were widely used at the time of the initial CIN studies. Reflective of this, contrast choice in patients with limited renal function varies between institution and surgeon. While CO₂ may be the sole choice of some surgeons, others will use dilute iso-osmolar nonionic contrast, iodixanol (Visipaque, GE Healthcare, Princeton, NJ), dilute low-osmolality contrast agents (LOCA), or a combination of CO₂ and dilute nonionic contrast. Won et al. [1] demonstrated that venography with small doses (10–15 mL) of dilute contrast media is safe in venous mapping in pre-dialysis patients. Further, several studies have shown iodixanol to be slightly less nephrotoxic than LOCA [25, 27]. While the benefit may be marginal, the additional cost of iodixanol over LOCA may be reasonable when large contrast volumes are anticipated.

CO2 contrast may also be considered in those patients with a documented allergy to iodinated contrast agents. The practice of substituting gadolinium contrast agents in these patients has been abandoned due to the risk of nephrogenic systemic fibrosis (NSF), even in patients who have initiated hemodialysis. In patients with a mild or moderate contrast reaction, premedication with steroids and Benadryl prior to iodinated contrast administration is another option. The premedication regimen varies slightly from institution to institution.

Interpretation

Normal Venous Anatomy of the Upper Extremity

Two types of veins are found in the upper extremity, superficial and deep. Superficial veins are located directly beneath the skin, between two layers of superficial fascia, and are used for the creation of AV fistula. Deep veins accompany arteries, creating venae comitantes.

The superficial veins of the upper extremity include digital, metacarpal, cephalic, basilic, and median. The venous network on the dorsal aspect of the hand drains into the main cephalic vein. Near the elbow, at the lateromedial portion of the arm, the main cephalic vein joins the median basilic (cubital) vein medially and the median cephalic vein laterally.

The accessory cephalic vein arises from the main cephalic vein, courses laterally and joins the median cephalic vein in the upper arm. Less commonly, the accessory cephalic vein originates from the dorsal venous network of the wrist and takes a variable course.

The basilic vein arises from the ulnar portion of the dorsal venous plexus. It courses medially until joining the median cubital vein at the lower third of the upper arm forming the upper arm basilic vein. At the elbow, a venous network in the shape of an “M” is formed by the accessory cephalic, the main (median) cephalic, the median cubital, and the forearm basilic veins.

Two brachial veins run parallel to the brachial artery. A perforating vein joins the deep brachial veins with the superficial veins at the elbow. These perforating veins play an important role in the diversion of blood flow from radiocephalic AVFs through deep veins to central veins when occlusion occurs at the median cephalic or basilic vein near the elbow [11].

The forearm basilic and median cubital veins converge to form the basilic vein, which courses medially in the upper arm. The basilic vein perforates the deep fascia, joins the deep brachial veins, and forms the axillary vein. The axillary vein may be single or duplicated which rejoins to form the subclavian vein at the lower border of the first rib. At the head of the clavicle, the subclavian vein joins the internal jugular vein, forming the brachiocephalic vein.

The main and accessory forearm cephalic veins converge to form the upper arm cephalic vein, which courses anterolaterally. After piercing the clavipectoral fascia, it enters the deltopectoral triangle and finally joins the subclavian vein, just below the clavicle. The cephalic arch is prone to stenosis from cephalic vein vascular access [11].