Vascular: Arteriovenous (AV) Hemodialysis Access

Arteriovenous Hemodialysis Access

Arteriovenous Fistula (AVF)

  • Best Survival of Dialysis Options
  • Timing:
    • Refer to Vascular Surgery One Creatinine Clearance < 25 mL/min
      • Per National Kidney Foundation KDOQI Guidelines
    • Ideally Create 6 Months Prior to Anticipated Need
      • Reduced Risk of Sepsis/Death (Largely from CVC Use)
  • Requires 6 Weeks to Mature Prior to Use
  • Rule of 6’s:
    • 6 Weeks to Mature
    • ≥ 2 x 3 = 6 mm Preoperative Diameters
    • < 6 mm from Skin Best
    • ≥ 6 in Segment Needed to Use
    • Must Support > 600 cc/min Flow

Minimum Maturation Time Prior to Use

  • CVC: Immediate
  • PD Cath: 2 Weeks
  • Prosthetic Graft: 2 Weeks
  • AVF: 6 Weeks

AVF Site Selection

  • Vasculature Requirements:
    • Artery Diameter ≥ 2.0 mm
    • Vein Diameter ≥ 2.0-3.0 mm
    • Patent Palmer Arch
  • General Approach:
    • Upper Extremity is Preferred to Lower Extremity
      • Easier Access & Lower Infection Risk
    • Non-Dominant Arm Preferred Over Dominant Arm
    • Most Distal Site Possible Preferred Over Proximal Sites
      • Preserve Proximal Sites for Future Access
      • Resulting Dilation of Proximal Veins Increases Success of Later Fistulas
    • Autogenous AVF Preferred Over Prosthetic Grafts
      • Higher Patency
      • Lower Complications
  • Highest Patency: End-of-Vein to Side-of-Artery
  • Options:
    • Posterior Radial Branch-Cephalic (Snuffbox) Fistula
    • Radial-Cephalic (Cimino) Fistula
      • High Early Failure Rate
    • Brachial-Cephalic Fistula
      • Easier Cannulation
    • Brachial-Basilic Fistula
      • Requires Superficialization of Deep Basilic Vein
      • Often Done in Two-Stages (Mature Before Superficialization)

Cimino AVF 1

Prosthetic Grafts

  • AVF Comparison:
    • Grafts Have Lower Primary Patency
    • Grafts Have Similar Long-Term Patency
    • Grafts Have Worse Outcomes Overall
  • Most Commonly Use 6 mm PTFE Grafts
  • Requires 2 Weeks to Heal Prior to Use (No Maturation Needed)
  • Use/Indications:
    • Forearm Prosthetic Grafts Should Be Considered a Bridge to Autogenous Upper Arm Fistulas
    • Upper Arm Prosthetic Grafts Used if No Adequate Veins are Available
  • Options:
    • Forearm:
      • Radial-Antecubital Straight Access
      • Radial-Antecubital Looped Access
      • Brachial-Antecubital Looped Access
    • Upper Arm:
      • Brachial-Axillary Straight Access
      • Brachial-Brachial Straight Access
      • Proximal Radial-Axillary Straight Access
      • Proximal Radial- Brachial Straight Access

Other Options

  • HeRO (Hemodialysis Reliable Outflow)
    • Catheter Placed Through Stenotic Vein
    • Option for Central Vein Stenosis
  • Leg Access Indications:
    • All Arm Options Exhausted
    • Young Women (Avoid Scars)
    • Paraplegics (Need Arms for Wheelchairs)

Arteriovenous Hemodialysis Access – Complications

Infection

  • Most Common Complication
  • Treatment:
    • Autogenous AVF: ABX 2-4 Weeks
    • Prosthetic Graft: Partial Graft Resection vs. Complete Excision

Access Failure

  • Failure of Maturation
    • Good Thrill but Unable to Cannulate
    • Cause: Anastomotic Stricture or Too Deep
    • Dx: US
    • May Require Angioplasty or Revision
  • Most Common Cause of Later Failure: Venous Outflow Stenosis
    • From Intimal Hyperplasia/Stenosis at Graft-Venous Anastomosis
    • Worsens with Time

Thrombosis

  • Autogenous AVF:
    • Thrombectomy Often Leads to Recurrent Thrombosis Due to Abnormal Underlying Surface & Trauma from Thromboembolectomy Catheter
    • Percutaneous Thrombectomy May Have Better Results
  • Prosthetic AV Graft:
    • No Single Best Treatment
    • Treatment:
      • Early (< 30 Days): Surgical Thrombectomy
        • Tolerates Balloon Thromboembolectomy Better Than Autogenous AVF
      • Later (> 30 Days): Percutaneous Thrombectomy

Fistula Thrombosis; To-and-From Waveform Indicating Outflow Obstruction 2

Access-Related Hand Ischemia (ARHI)/Steal Syndrome

  • Ischemia Distal to Fistula
  • Most Common in Proximal Fistulas
  • Presentation: Pain, Numbness, Burning, Coolness & Weakness
  • Diagnosis: Duplex US & Angiography
  • Grade:
    • Grade 0: No Symptoms
    • Grade 1: Mild – Few Symptoms & Flow Augmentation with Occlusion
    • Grade 2: Moderate – Claudication & Intermittent Pain Only During Dialysis
    • Grade 3: Severe – Rest Pain & Tissue Loss
  • Treatment:
    • Mild: Exercise
    • Moderate: May Require Surgical Intervention
    • Severe: Surgical Intervention
  • Surgical Procedures:
    • DRIL Procedure (Distal Revascularization & Interval Ligation)
      • Arterial Bypass Originating Proximal to the Fistula and Terminating Distal to the Fistula
      • Ligate the Artery Just Distal to the Fistula Anastomosis
      • Generally the Procedure of Choice
    • RUDI Procedure (Revision Using Distal Inflow)
      • Ligate Fistula at Arterial Anastomosis
      • Reestablish Flow with Graft from a More Distal Arterial Site
    • Banding
      • Placing a Single Tie/Band Around the Fistula Near the Arterial Anastomosis
      • Creates Stenosis & Therefore Decreases Flow
    • Fistula Ligation
      • Generally the Last Resort Only for Limb Salvage

Steal Syndrome (a), DRIL Procedure (b), RUDI Procedure (c) 1

Ischemic Monomelic Neuropathy (IMN)

  • Acute Shunting of Blood from Distal Nerve Fibers
    • Can Potentially Cause Irreversible Damage
  • Presentation: Severe Pain, Numbness, Paresthesias & Numbness
    • Typically Immediately After Surgery
  • Risk Factors: Diabetes, Atherosclerosis, Female & Proximal Access
  • Treatment: Emergent Flow Augmentation or Fistula Ligation

Venous Hypertension

  • Most Common Cause: Central Vein Stenosis – Mostly from Central Venous Catheters
    • Stenosis Cannot Handle Sudden Increased Venous Return
    • Can Be Seen in Superior Vena Cava Syndrome
  • Presentation: Disabling Swelling & Distal Pain
    • Can Risk Access Patency
  • Diagnosis: Venography (Gold Standard) & Duplex US
  • Treatment: Percutaneous Transluminal Angioplasty (PTA)

High-Output Cardiac Failure

  • Fistula Creates a Left-to-Right Shunt
    • Exaggeration of Normal Congestive Heart Failure
  • Nicoladoni-Branham Sign: AVF Compression Causes Decreased HR & Increased BP
    • From Increased Peripheral Vascular Resistance & Afterload
    • Large Changes Seen with Compression
  • Treatment: Ligation or Surgical Plication (Band Narrowing Just Beyond Arterial Anastomosis)

Aneurysm

  • Aneurysm
    • Requires Cessation of Cannulation Punctures
    • First Step: Fistulogram to Rule Out High Outflow Resistance
    • Treatment: Varies (Relocation, Partial Resection, Excision or Angioplasty)
    • *See Vascular: Peripheral Aneurysm
  • Pseudoaneurysm

Bleeding

  • Bleeding Can Be Rapid & Profuse
  • The Most Common Cause is Repeated Trauma from Needle Cannulation During Dialysis
    • Sites Should Be Rotated Each Session with Proper Technique to Avoid Risk
  • Treatment:
    • Initial Measure: Direct Pressure Can Control Most
      • Consider Tourniquet if Needed
      • Bleeding Often Stops After Pressure Held for 15-20 Minutes
    • Options to Control Bleeding:
      • Topical Agents (Thrombin/Surgicel/QuikClot)
      • Suture Closure at Bedside
      • Consider Correction of Coagulopathy if Needed
      • Exploration in OR
    • Can Consider Discharge if Hemodynamically Stable with Minimal Blood Loss
  • Bedside Suture Closure:
    • Assistant Should Place Pressure Above & Below to Slow Bleeding While Repairing
    • Technique:
      • Figure-of-Eight or Purse-String Fashion
      • Generally Closing Skin is Sufficient – Scar Tissue from Repeated Access
    • Suture Choice:
      • Ideally Use a Non-Cutting Needle to Avoid Further Injury to Fistula
      • 3-0 Nylon or 5-0 Prolene are Commonly Used

References

  1. Santoro D, Benedetto F, Mondello P, Pipitò N, Barillà D, Spinelli F, Ricciardi CA, Cernaro V, Buemi M. Vascular access for hemodialysis: current perspectives. Int J Nephrol Renovasc Dis. 2014 Jul 8;7:281-94.(License: CC BY-NC-3.0)
  2. Teodorescu V, Gustavson S, Schanzer H. Duplex ultrasound evaluation of hemodialysis access: a detailed protocol. Int J Nephrol. 2012;2012:508956. (License: CC BY-3.0)
  3. Elwakeel H, Elalfy K. Vascular Access for Hemodialysis – How to Maintain in Clinical Practice. Intech. 2013. (License: CC BY-3.0)