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/

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

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

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.

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.

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 venography if a patient has a history of a central venous catheter or clinical signs of venous hypertension.
A history of SVC obstruction from any cause can preclude permanent AV access creation in both upper extremities

Endovascular approaches to venous outflow stenosis can be first-line treatment options, due to their minimal risk. They can also be performed at the same time as a diagnostic venogram.
Angioplasty alone or with stenting are the endovascular options.

In a study by Bakken et al2 that compared primary high-pressure balloon angioplasty versus stenting, primary patency was equivalent between groups, with 30-day rates of 76% for both groups and 12-month rates of 29% for angioplasty and 21% for stenting. Assisted primary patency was also equivalent with a 30-day patency rate of 81% and 12-month rate of 73% for the angioplasty group, 84% at 30 days, and 46% at 12 months for the stenting group. This study, along with others, shows that the major downside of endovascular interventions, whether angioplasty or stenting, often require repeat intervention and have poor long-term patency.
For subclavian vein stenosis, angioplasty alone is appropriate due to its anatomical location that can put a stent at risk for extrinsic compression from the first rib and clavicle.

Possible bypasses include axillary-axillary, axillary-jugular, axillary-right atrial, and axillary-femoral. In these bypasses, the preferred conduits are autogenous saphenous or femoral veins.

In cases where the proximal subclavian vein is obstructed, a jugular vein turndown can be performed. In this procedure the distal jugular vein is transected, sewed end-to-side at the distal subclavian vein, effectively acting as a bypass route for that obstructed segment.

The Hemoaccess Reliable Outflow (HeRO) Vascular Access Device can be used as a hybrid approach, combining endovascular and open surgical techniques to bypass a central venous occlusion and provide a reliable outflow for dialysis.

This device has a PTFE inflow limb that is sewn end-to-side onto the brachial artery. This limb is tunneled subcutaneously and connected to a silicone-coated nitinol outflow catheter that is inserted into a central vein and tracked directly into the right atrium. This effectively bypasses central venous stenoses. In the largest study to date on HeRO access grafts placed in 167 patients,3 HeRO primary and secondary patency was 48.8% and 90.8%, respectively, at 12 months. Interventions to maintain or re-establish patency were required in 71.3% of patients resulting in an intervention rate of 1.5/year. Access-related infections were reported in 4.3% patients. The authors concluded that HeRO device had performed comparably to standard AVGs and had proven superior to tunneled dialysis catheters in terms of patency, intervention, and infection rates.

If no treatment options for venous hypertension or outflow obstruction are available, an alternate AV access site can be created, either in the contralateral arm if the SVC is uninvolved, or through placement of femoral AV access or a peritoneal dialysis catheter.

Bleeding can be caused by high venous pressure after dialysis, pseudoaneurysm rupture, or trauma.
Patients with end stage renal disease (ESRD) have a baseline elevated risk of bleeding due to uremia-induced platelet dysfunction and use of systemic anticoagulation within the hemodialysis circuit. Additional risk factors include dialysis through an AV graft, hypertension, longer duration of access use, and compromised integrity of the vascular access due to complications (clotting, infection) or invasive procedures.