Holding Pressure: AV Fistula/Graft Complications Part 2

Resources: 

• Rutherford Chapters (10th ed.): 174, 175, 177, 178

• Prior Holding Pressure episode on AV access creation: https://www.audiblebleeding.com/vsite-hd-access/

• The Society for Vascular Surgery: Clinical practice guidelines for the surgical placement and maintenance of arteriovenous hemodialysis access: https://www.jvascsurg.org/article/S0741-5214%2808%2901399-2/fulltext 

• KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update: https://pubmed.ncbi.nlm.nih.gov/32778223/ 

 

1. Venous Hypertension

 

• Definition

• A functioning AV circuit delivers high volume arterial flow towards a stenotic venous segment, causing buildup in pressure and venous hypertension.

• If there are few or no branching veins between the access and stenosis, thrombosis could occur

 

• Etiology

• The most common etiology is venous stenosis caused by a history of vessel wall trauma by centrally-inserted venous devices such as tunneled and non-tunneled dialysis catheters, central lines, pacemakers, or defibrillator.

• In a study performed at a large academic medical center1, new hemodynamically significant central venous stenosis was associated with the duration of catheter dependence (26% in patients with CVCs for more than 6 months, versus 11% in patients with CVCs for less than 6 months).

• PICC lines can directly damage cephalic and basilic veins

• Venous stenosis can often go undetected until AV access creation occurs

 

• Patient Presentation

• Symptoms of venous insufficiency will be present– most commonly regional edema, in the area of venous stenosis. If there are patent venous branches between the AV anastomosis and the stenotic area, swelling can occur throughout the arm. Pigmentation, induration, dermatosclerosis, and ulceration may also be observed.

• An extensive collateral network of veins may be visible throughout anterior chest, shoulder, or flank

• SVC obstruction can result in swelling of the head, neck and shoulders, as well as a feeling of head and neck fullness, airway compromise, and visual problems

• Normal palpable thrill can be replaced by a strong pulse

• Dialysis can be complicated by difficulty with needle access, recirculation syndrome, and arm swelling after dialysis sessions.
  
  

• Workup 

• Central vein thrombosis can be hard to detect on ultrasound because clavicle and sternum can block transmission

• Venography is essential to determine the presence and severity of venous stenosis or occlusion.

 

• Prevention

• The ideal scenario is to avoid central dialysis catheters completely, and this involves evaluating CKD patients and placing AVF or AVG before the need for dialysis arises. 

• If a patient presents placement of an AVF/AVG, it is important to perform