BAM! A Pictorial Essay of Early Dialysis Access Interventions

A hemodialysis (HD) arteriovenous fistula (AVF) is an iatrogenic shunt between an artery and vein created surgically or endovascularly in dialysis patients {1}. A mature AVF allows for high flow hemodialysis without the need for placement of a tunneled catheter. In this pictoral essay, we will address kDOQI recommendations for "Fistula First" and the importance of moving from catheter-based dialysis to arm access as soon as possible. More specifically we will present common causes for delayed AVF maturity and the interventions available to treat them.

Complications over the lifetime of an AVF include aneurysm, pseudoaneurysm, stenosis, and thrombosis {2}. Of these, stenosis is a common pre-existing or early cause of delayed maturation {3}. We will highlight cases of inflow venous stenosis secondary to post-surgical scarring, venous valves, intramuscular course of veins in upper arm and shoulder, and prior subclavian and IJ catheters.  Additionally, examples of poor maturity secondary to anatomic variations or the presence of multiple venous side branches will be presented.

Having identified the common causes for delayed maturity for AVFs, we will also highlight appropriate interventions with examples of balloon-assisted maturation (BAM) and venous side branch embolization/ligation. This educational presentation is designed for the practitioner seeking to improve early outcomes for their dialysis patient population by understanding the common causes of delayed maturity for an AVF and how to improve outcomes with early intervention.

Clinical Findings/Procedure Details: We'll highlight cases of inflow venous stenosis, along with examples of appropriate interventions such as BAM.

Conclusion and/or Teaching Points:

Inflow venous stenosis from post-surgical scarring: scarring in the lumen of vessels occludes flow {4}

Stenosis secondary to venous valves: the cephalic arch has at least twice as many valves compared to any similar portion of the cephalic vein leading to turbulent and sometimes occlusive blood flow {5}

Stenosis secondary to intramuscular course of veins in upper arm and shoulder: muscular compression of vessels occludes flow

Stenosis secondary to prior subclavian and IJ catheters: stenosis is a well-known complication of central venous catheterization {4}

Anatomic variations: a single channel that joins the axillary vein to form the subclavian vein is the most common variant of the cephalic arch; a bifid arch may also be encountered {5}

Poor maturity secondary to multiple venous side branches: sides branches divert flow from main AVF channel delaying its maturation {5}