What is the management for a patient with persistent bleeding from their arteriovenous fistula (AVF) after dialysis?

Performing a Fistulogram for Persistent AV Fistula Bleeding After Dialysis

For a patient with persistent bleeding from an arteriovenous fistula (AVF) up to an hour after dialysis, a fistulogram should be performed immediately as it is the gold standard for evaluating access dysfunction, which is likely causing the bleeding complication. 1

Initial Assessment and Management of Bleeding

1. Direct pressure management:

   • Apply direct pressure to the bleeding site using sterile gauze
   • If bleeding continues despite pressure, consider using a bottle cap or similar rigid object to focus pressure directly over the bleeding site 2
   • Do not apply a tourniquet as this can compromise the fistula

2. Immediate clinical evaluation:

   • Assess vital signs for hemodynamic stability
   • Evaluate for signs of significant blood loss (tachycardia, hypotension)
   • Check hemoglobin level to quantify blood loss 3
   • Examine the fistula for:
     • Aneurysm formation
     • Skin ulceration over the access
     • Signs of infection
     • Abnormal thrill or bruit

Fistulogram Procedure

Preparation

1. Patient positioning:

   • Position the patient supine with the access arm extended on an arm board
   • Ensure the entire access arm and central veins are included in the imaging field

2. Equipment needed:

   • Fluoroscopy equipment
   • Non-ionic contrast material (consider diluted contrast at 25% for better visualization) 1
   • For patients not yet on dialysis, use non-nephrotoxic contrast, carbon dioxide, or ultrasound 1
   • Sterile drapes, gloves, and gown
   • Local anesthetic (lidocaine 1%)
   • Access needles (21-gauge for initial access)
   • Guidewires, catheters, and balloons for potential intervention

Procedure Steps

1. Access the fistula:

   • Clean the site with antiseptic solution
   • Administer local anesthetic
   • Access the fistula with a 21-gauge needle directed in the antegrade direction
   • Confirm intraluminal placement with blood return

2. Contrast injection:

   • Connect the needle to extension tubing and a syringe with contrast
   • Inject contrast slowly under fluoroscopic guidance
   • Obtain images of the entire fistula from arterial anastomosis to central veins

3. Image acquisition:

   • Capture images of:
     • Arterial anastomosis
     • Entire fistula conduit
     • Venous outflow tract
     • Central veins up to the right atrium
   • Look specifically for:
     • Stenosis (>50% narrowing is significant) 1
     • Thrombus
     • Aneurysms
     • Extravasation indicating rupture
     • Pseudoaneurysm formation

4. Intervention (if needed):

   • For stenosis: Perform percutaneous transluminal angioplasty (PTA) 1
   • For resistant stenosis: Consider high-pressure balloons (25-30 atmospheres) 1
   • For thrombosis: Perform mechanical thrombectomy or thrombolysis 1
   • For aneurysm with bleeding: Consider covered stent placement or surgical referral

5. Hemostasis:

   • Remove the needle while applying gentle pressure
   • Apply pressure until hemostasis is achieved
   • Avoid excessive pressure that could compromise the fistula

Post-Procedure Management

1. Immediate post-procedure care:

   • Monitor the access site for bleeding
   • Assess fistula function (presence of thrill and bruit)
   • Evaluate distal circulation

2. Follow-up plan:

   • If aneurysm is identified: The aneurysmal segment should not be cannulated 1
   • If ulceration is present: Surgical consultation is required as simple suturing may not be effective 4
   • If infection is present: Initiate broad-spectrum antibiotics (vancomycin plus an aminoglycoside) 1

Special Considerations

1. For ulcerated, bleeding fistulas:

   • These are life-threatening and require prompt surgical intervention 4
   • Simple suturing is often only a temporary measure 4
   • Definitive treatment may include excision with primary closure, vein patching, or end-to-end anastomosis 4

2. For aneurysmal fistulas:

   • Postaneurysmal stenosis often drives aneurysm formation and should be corrected 1
   • The aneurysmal segment should not be cannulated 1

3. For thrombosed fistulas:

   • Thrombectomy should be attempted as early as possible 1
   • Success rates are greater than 90% with proper techniques 1

4. For infected fistulas:

   • Treat as subacute bacterial endocarditis with 6 weeks of antibiotic therapy 1
   • Surgical excision may be necessary in cases of septic emboli 1

Remember that persistent bleeding from an AVF is a potentially fatal complication that requires urgent evaluation and treatment 5. The fistulogram is essential not only for diagnosis but also to guide immediate intervention to preserve the access and prevent life-threatening hemorrhage.