link
Bookmarks
Hemodialysis Access Surveillance and Intervention
Keith B. Quencer, MD
To access 4,300 diagnoses written by the world's leading experts in radiology, please log in or subscribe.Log inSubscribe

KEY FACTS

  • Terminology

    • Preprocedure

      • Procedure

        TERMINOLOGY

        • Definitions

          • Hemodialysis (HD)
            • Patient's blood is modified by going through dialyzer
              • Certain solutes are removed
                • e.g., potassium, phosphorus, and urea
              • Dialysate solutes are added
                • e.g., bicarbonate
              • Plasma water often removed
          • End-stage renal disease
            • a.k.a. chronic kidney disease (CKD) stage 5
            • Glomerular filtration rate (GFR) < 15 mL/min/1.73 m2
            • Need HD, peritoneal dialysis, or kidney transplant for medium-term survival
          • Arteriovenous fistula (AVF)
            • Surgical anastomosis between artery and vein
              • Results in dilation and arterialization of vein draining fistula
              • Requires maturation period before use
                • Typically 8-12 weeks maturation
                • ~ 50% never able to be used
              • Once mature, less infections and longer lifespan than arteriovenous grafts (AVGs)
            • Common types of AVF
              • Radiocephalic (RC) fistula (forearm)
                • Preferred dialysis access
                • Problem: Low rates of maturation
                • Typical site of stenosis: Juxtaanastomotic segment
              • Brachiocephalic fistula (upper arm)
                • 2nd preferred dialysis access
                • Used when radial artery or forearm cephalic vein are unsuitable for RC creation
                • Problems: High rate of dialysis-associated steal syndrome (DASS), precludes subsequent ipsilateral forearm fistula creation
                • Typical site of stenosis: Cephalic arch
              • Brachiobasilic fistula (upper arm)
                • Used when upper arm cephalic vein unsuitable for AVF creation
                • Problems: Difficult and 2-stage surgery, high rate of steal syndrome
                • Typical site of stenosis: Proximal swing segment
          • Mature fistula
            • Mature fistula is able to be repeatedly punctured and provide adequate flow for dialysis
            • Satisfies "rule of 6s"
              • Flow > 600 mL/min
              • Diameter > 0.6 cm
              • No more than 0.6 cm deep
              • Should be mature by 6 weeks
          • Immature fistula
            • Occurs in > 50% of newly created AVFs
              • Inflow stenosis
                • Most common cause of nonmaturation
                • Does not allow for dilation and arterialization of fistula
              • Competing outflow veins
                • Accessory veins: Naturally occurring branches arising from venous outflow tract; treat with ligation, embolization
                • Collateral veins: Alternative drainage pathways; develop in setting of downstream stenosis; treat by addressing underlying stenosis
              • Fistula that has failed to mature at 6 weeks should trigger further evaluation
          • AVG
            • Surgically created connection between artery and vein, using prosthetic conduit to provide vascular access for HD treatment
            • Used if unsuitable vascular anatomy for AVF
              • Suitable: Artery > 2 mm in diameter, vein > 2.5 mm in diameter
            • AVG has shorter lifespan than AVF
              • 6-10x greater infection risk and thrombosis
            • Polytetrafluoroethylene (PTFE) graft most frequently used AVG material
              • Can be used within 2-3 weeks of construction
              • Gore Acuseal able to be used 24 hours after creation
            • Types of AVG
              • Loop or straight configuration
                • Forearm preferred over upper arm
                • Arm preferred over groin
              • Prosthetic axillary-axillary arteriovenous straight access (necklace graft)
                • Used for patients with exhaustion of all other upper limb accesses but patent superior vena cava, subclavian and brachiocephalic veins
            • Typical site of stenosis: Graft-vein anastomosis
          • Cephalic arch
            • Most central portion of cephalic vein
              • Arches through deltopectoral groove to join axillary vein
            • Most frequent site of stenosis in dysfunctional brachiocephalic fistulas (40-77%)
              • Rarely cause of dysfunction in RC fistulas
            • Etiologies of stenosis
              • Extrinsic compression by clavipectoral fascia
              • High concentration of valves in this venous segment
              • Turbulence caused by sharp turn of arch combined with high flow rate
            • Difficult to treat
              • High-pressure balloons often needed
                • Associated high rate of vessel rupture
              • Low primary patency rate at 1 year (~ 20%) with angioplasty alone
          • HeRO graft (hemodialysis reliable outflow): Merit Medical
            • Arterial graft component
              • 6-mm inner diameter
              • Material: Expanded polytetrafluoroethylene (ePTFE)
            • Venous outflow component
              • 5-mm inner diameter
              • Radiopaque silicone, reinforced with braided nitinol
            • Titanium connector between arterial graft and venous outflow
            • Used for failing AVF/AVG secondary to central venous stenosis
            • Catheter dependent patients
            • Benefits
              • Lower infection compared to catheters
              • Improved HD adequacy compared to catheters
              • Higher patency rates compared to catheter
          • Qa: Access flow rate
            • Varies depending on access configuration, presence of stenosis, arterial inflow
          • Qb: Dialysis pump flow rate
            • Typically set at 350-400 mL/min
          • Kt/V: Number quantifying dialysis treatment adequacy
            • K: Dialyzer clearance of urea
            • T: Dialysis time
            • V: Volume of distribution of urea, ~ equal to patient's total body water
          • Monitoring: Periodic physical examination and review of routinely gathered data of dialysis patients performed to detect underdialysis and dysfunctional accesses prior to thrombosis
            • Weekly physical examination
            • Review of routinely gathered data collected during HD
              • Dialysis adequacy: Kt/V
                • Value < 1.2 or decrease by > 0.2 triggers referral for intervention
              • Dynamic pump pressures
                • Unreliable if taken in isolation
                • If abnormal trend or with other access abnormalities can be predictive of the side of stenosis
            • Needling problems
              • Prolonged bleeding suggests outflow stenosis
              • Difficulty with cannulation suggests inflow stenosis
          • Surveillance: Instrument-based, periodic evaluation performed to detect underdialysis and dysfunctional accesses prior to thrombosis
            • Access flows
              • Measured by ultrasound dilution/conductance, dilution/thermal, dilution/Doppler
                • AVG < 600 mL/min or < 1,000 mL/min if > 25% drop → referral
                • AVF < 400 mL/min or < 1,000 mL/min if > 25% drop → referral
            • Static venous pressure
              • Useful in AVGs
                • Insensitive to detect inflow problems, which are more common in AVFs
              • Intraaccess pressure to mean arterial pressure (MAP) ratio > 0.5 triggers referral
            • Detection of recirculation
              • Occurs when Qa < Qb
                • Could be due to inflow or outflow problem
              • Recirculation > 10% triggers referral
              • Not sensitive surveillance technique AVGs
              • AVGs can thrombose with Qa < 600 mL/min
                • Recirculation occurs when flow rates are < pump rates, typically set at 350-400 mL/min
            • Doppler ultrasound
              • Can measure flow rates, detect sites of stenosis
          • DASS
            • Arterial insufficiency ipsilateral to HD access
            • Risk factors
              • Diabetic patients with multiple prior shunts
              • Female gender
              • Brachial artery inflow
              • High-flow shunts/large anastomoses
              • Grafts (2.7-8.0%) more common than fistulas (< 2.0%)
            • Stages
              • Grade 1 (mild): Cool extremity but otherwise few symptoms
                • Distal flow augmentation with access occlusion
                • No treatment needed
              • Grade 2 (moderate): Intermittent ischemia
                • Pain during dialysis or with exercise
                • Treatment occasionally needed
              • Grade 3 (severe): Rest pain/tissue loss
                • Treatment mandatory, often with access ligation
          • National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI)
            • Provides multidisciplinary evidence-based clinical guidelines for CKD patients
              • Includes all stages of CKD and all aspects of care
            • Vascular Access Guidelines most relevant to interventional procedures
              • Published 2006, update forthcoming January 2018

        PREPROCEDURE

        • Indications

          • Contraindications

            • Preprocedure Imaging

              • Getting Started

                PROCEDURE

                • Patient Position/Location

                  • Equipment Preparation

                    • Procedure Steps

                      • Findings and Reporting

                        • Alternative Procedures/Therapies

                          POST PROCEDURE

                          • Things to Do

                            • Things to Avoid

                              OUTCOMES

                              • Complications

                                • Expected Outcomes

                                  Selected References

                                  1. Vascular Access KDOQI Guidelines. Clinical practice guidelines for hemodialysis adequacy. http://www2.kidney.org/professionals/KDOQI/guideline_upHD_PD_VA/. Reviewed February 16, 2017. Accessed February 16, 2017
                                  2. Haskal ZJ et al: Prospective, randomized, concurrently-controlled study of a stent graft versus balloon angioplasty for treatment of arteriovenous access graft stenosis: 2-year results of the RENOVA study. J Vasc Interv Radiol. 27(8):1105-1114.e3, 2016
                                  3. Koirala N et al: Monitoring and surveillance of hemodialysis access. Semin Intervent Radiol. 33(1):25-30, 2016
                                  4. Sequeira A: Stent migration and bail-out strategies. J Vasc Access. 17(5):380-5, 2016
                                  5. Akoh JA et al: Review of transposed basilic vein access for hemodialysis. J Vasc Access. 16(5):356-63, 2015
                                  6. Balaz P et al: True aneurysm in autologous hemodialysis fistulae: definitions, classification and indications for treatment. J Vasc Access. 16(6):446-53, 2015
                                  7. Maytham GG et al: The use of the early cannulation prosthetic graft (Acuseal™) for angioaccess for haemodialysis. J Vasc Access. 16(6):467-71, 2015
                                  8. Quencer KB et al: Arteriovenous fistulas and their characteristic sites of stenosis. AJR Am J Roentgenol. 205(4):726-34, 2015
                                  9. Swinnen JJ et al: Paclitaxel drug-eluting balloons to recurrent in-stent stenoses in autogenous dialysis fistulas: a retrospective study. J Vasc Access. 16(5):388-93, 2015
                                  10. Vasanthamohan L et al: The management of cephalic arch stenosis in arteriovenous fistulas for hemodialysis: a systematic review. Cardiovasc Intervent Radiol. 38(5):1179-85, 2015
                                  11. Agarwal AK et al: How should symptomatic central vein stenosis be managed in hemodialysis patients? Semin Dial. 27(3):278-81, 2014
                                  12. Hart D et al: Modification of the HeRO graft allowing earlier cannulation and reduction in catheter dependent days in patients with end stage renal disease: a single center retrospective review. ScientificWorldJournal. 2014:318629, 2014
                                  13. Modabber M et al: Central venous disease in hemodialysis patients: an update. Cardiovasc Intervent Radiol. 36(4):898-903, 2013
                                  14. Samett EJ et al: Augmented balloon-assisted maturation (aBAM) for nonmaturing dialysis arteriovenous fistula. J Vasc Access. 12(1):9-12, 2011
                                  15. Bittl JA: Catheter interventions for hemodialysis fistulas and grafts. JACC Cardiovasc Interv. 3(1):1-11, 2010
                                  16. Haskal ZJ et al: Stent graft versus balloon angioplasty for failing dialysis-access grafts. N Engl J Med. 362(6):494-503, 2010
                                  17. Monroy-Cuadros M et al: Risk factors associated with patency loss of hemodialysis vascular access within 6 months. Clin J Am Soc Nephrol. 5(10):1787-92, 2010
                                  18. Allon M et al: Hemodialysis vascular access monitoring: current concepts. Hemodial Int. 13(2):153-62, 2009
                                  19. Whittier WL: Surveillance of hemodialysis vascular access. Semin Intervent Radiol. 26(2):130-8, 2009
                                  20. Casey ET et al: Surveillance of arteriovenous hemodialysis access: a systematic review and meta-analysis. J Vasc Surg. 48(5 Suppl):48S-54S, 2008
                                  21. Gelbfish GA: Clinical surveillance and monitoring of arteriovenous access for hemodialysis. Tech Vasc Interv Radiol. 11(3):156-66, 2008
                                  22. Mauro MA et al: Image-Guided Interventions. 1st ed. Philadelphia: Saunders, 2008
                                  23. Nassar GM: Endovascular management of the "failing to mature" arteriovenous fistula. Tech Vasc Interv Radiol. 11(3):175-80, 2008
                                  24. Rayner HC et al: Creation, cannulation and survival of arteriovenous fistulae: data from the Dialysis Outcomes and Practice Patterns Study. Kidney Int. 63(1):323-30, 2003
                                  25. Gallego Beuter JJ et al: Early detection and treatment of hemodialysis access dysfunction. Cardiovasc Intervent Radiol. 23(1):40-6, 2000
                                  Related Anatomy
                                  Loading...
                                  Related Differential Diagnoses
                                  Loading...
                                  References
                                  Tables

                                  Tables

                                  KEY FACTS

                                  • Terminology

                                    • Preprocedure

                                      • Procedure

                                        TERMINOLOGY

                                        • Definitions

                                          • Hemodialysis (HD)
                                            • Patient's blood is modified by going through dialyzer
                                              • Certain solutes are removed
                                                • e.g., potassium, phosphorus, and urea
                                              • Dialysate solutes are added
                                                • e.g., bicarbonate
                                              • Plasma water often removed
                                          • End-stage renal disease
                                            • a.k.a. chronic kidney disease (CKD) stage 5
                                            • Glomerular filtration rate (GFR) < 15 mL/min/1.73 m2
                                            • Need HD, peritoneal dialysis, or kidney transplant for medium-term survival
                                          • Arteriovenous fistula (AVF)
                                            • Surgical anastomosis between artery and vein
                                              • Results in dilation and arterialization of vein draining fistula
                                              • Requires maturation period before use
                                                • Typically 8-12 weeks maturation
                                                • ~ 50% never able to be used
                                              • Once mature, less infections and longer lifespan than arteriovenous grafts (AVGs)
                                            • Common types of AVF
                                              • Radiocephalic (RC) fistula (forearm)
                                                • Preferred dialysis access
                                                • Problem: Low rates of maturation
                                                • Typical site of stenosis: Juxtaanastomotic segment
                                              • Brachiocephalic fistula (upper arm)
                                                • 2nd preferred dialysis access
                                                • Used when radial artery or forearm cephalic vein are unsuitable for RC creation
                                                • Problems: High rate of dialysis-associated steal syndrome (DASS), precludes subsequent ipsilateral forearm fistula creation
                                                • Typical site of stenosis: Cephalic arch
                                              • Brachiobasilic fistula (upper arm)
                                                • Used when upper arm cephalic vein unsuitable for AVF creation
                                                • Problems: Difficult and 2-stage surgery, high rate of steal syndrome
                                                • Typical site of stenosis: Proximal swing segment
                                          • Mature fistula
                                            • Mature fistula is able to be repeatedly punctured and provide adequate flow for dialysis
                                            • Satisfies "rule of 6s"
                                              • Flow > 600 mL/min
                                              • Diameter > 0.6 cm
                                              • No more than 0.6 cm deep
                                              • Should be mature by 6 weeks
                                          • Immature fistula
                                            • Occurs in > 50% of newly created AVFs
                                              • Inflow stenosis
                                                • Most common cause of nonmaturation
                                                • Does not allow for dilation and arterialization of fistula
                                              • Competing outflow veins
                                                • Accessory veins: Naturally occurring branches arising from venous outflow tract; treat with ligation, embolization
                                                • Collateral veins: Alternative drainage pathways; develop in setting of downstream stenosis; treat by addressing underlying stenosis
                                              • Fistula that has failed to mature at 6 weeks should trigger further evaluation
                                          • AVG
                                            • Surgically created connection between artery and vein, using prosthetic conduit to provide vascular access for HD treatment
                                            • Used if unsuitable vascular anatomy for AVF
                                              • Suitable: Artery > 2 mm in diameter, vein > 2.5 mm in diameter
                                            • AVG has shorter lifespan than AVF
                                              • 6-10x greater infection risk and thrombosis
                                            • Polytetrafluoroethylene (PTFE) graft most frequently used AVG material
                                              • Can be used within 2-3 weeks of construction
                                              • Gore Acuseal able to be used 24 hours after creation
                                            • Types of AVG
                                              • Loop or straight configuration
                                                • Forearm preferred over upper arm
                                                • Arm preferred over groin
                                              • Prosthetic axillary-axillary arteriovenous straight access (necklace graft)
                                                • Used for patients with exhaustion of all other upper limb accesses but patent superior vena cava, subclavian and brachiocephalic veins
                                            • Typical site of stenosis: Graft-vein anastomosis
                                          • Cephalic arch
                                            • Most central portion of cephalic vein
                                              • Arches through deltopectoral groove to join axillary vein
                                            • Most frequent site of stenosis in dysfunctional brachiocephalic fistulas (40-77%)
                                              • Rarely cause of dysfunction in RC fistulas
                                            • Etiologies of stenosis
                                              • Extrinsic compression by clavipectoral fascia
                                              • High concentration of valves in this venous segment
                                              • Turbulence caused by sharp turn of arch combined with high flow rate
                                            • Difficult to treat
                                              • High-pressure balloons often needed
                                                • Associated high rate of vessel rupture
                                              • Low primary patency rate at 1 year (~ 20%) with angioplasty alone
                                          • HeRO graft (hemodialysis reliable outflow): Merit Medical
                                            • Arterial graft component
                                              • 6-mm inner diameter
                                              • Material: Expanded polytetrafluoroethylene (ePTFE)
                                            • Venous outflow component
                                              • 5-mm inner diameter
                                              • Radiopaque silicone, reinforced with braided nitinol
                                            • Titanium connector between arterial graft and venous outflow
                                            • Used for failing AVF/AVG secondary to central venous stenosis
                                            • Catheter dependent patients
                                            • Benefits
                                              • Lower infection compared to catheters
                                              • Improved HD adequacy compared to catheters
                                              • Higher patency rates compared to catheter
                                          • Qa: Access flow rate
                                            • Varies depending on access configuration, presence of stenosis, arterial inflow
                                          • Qb: Dialysis pump flow rate
                                            • Typically set at 350-400 mL/min
                                          • Kt/V: Number quantifying dialysis treatment adequacy
                                            • K: Dialyzer clearance of urea
                                            • T: Dialysis time
                                            • V: Volume of distribution of urea, ~ equal to patient's total body water
                                          • Monitoring: Periodic physical examination and review of routinely gathered data of dialysis patients performed to detect underdialysis and dysfunctional accesses prior to thrombosis
                                            • Weekly physical examination
                                            • Review of routinely gathered data collected during HD
                                              • Dialysis adequacy: Kt/V
                                                • Value < 1.2 or decrease by > 0.2 triggers referral for intervention
                                              • Dynamic pump pressures
                                                • Unreliable if taken in isolation
                                                • If abnormal trend or with other access abnormalities can be predictive of the side of stenosis
                                            • Needling problems
                                              • Prolonged bleeding suggests outflow stenosis
                                              • Difficulty with cannulation suggests inflow stenosis
                                          • Surveillance: Instrument-based, periodic evaluation performed to detect underdialysis and dysfunctional accesses prior to thrombosis
                                            • Access flows
                                              • Measured by ultrasound dilution/conductance, dilution/thermal, dilution/Doppler
                                                • AVG < 600 mL/min or < 1,000 mL/min if > 25% drop → referral
                                                • AVF < 400 mL/min or < 1,000 mL/min if > 25% drop → referral
                                            • Static venous pressure
                                              • Useful in AVGs
                                                • Insensitive to detect inflow problems, which are more common in AVFs
                                              • Intraaccess pressure to mean arterial pressure (MAP) ratio > 0.5 triggers referral
                                            • Detection of recirculation
                                              • Occurs when Qa < Qb
                                                • Could be due to inflow or outflow problem
                                              • Recirculation > 10% triggers referral
                                              • Not sensitive surveillance technique AVGs
                                              • AVGs can thrombose with Qa < 600 mL/min
                                                • Recirculation occurs when flow rates are < pump rates, typically set at 350-400 mL/min
                                            • Doppler ultrasound
                                              • Can measure flow rates, detect sites of stenosis
                                          • DASS
                                            • Arterial insufficiency ipsilateral to HD access
                                            • Risk factors
                                              • Diabetic patients with multiple prior shunts
                                              • Female gender
                                              • Brachial artery inflow
                                              • High-flow shunts/large anastomoses
                                              • Grafts (2.7-8.0%) more common than fistulas (< 2.0%)
                                            • Stages
                                              • Grade 1 (mild): Cool extremity but otherwise few symptoms
                                                • Distal flow augmentation with access occlusion
                                                • No treatment needed
                                              • Grade 2 (moderate): Intermittent ischemia
                                                • Pain during dialysis or with exercise
                                                • Treatment occasionally needed
                                              • Grade 3 (severe): Rest pain/tissue loss
                                                • Treatment mandatory, often with access ligation
                                          • National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI)
                                            • Provides multidisciplinary evidence-based clinical guidelines for CKD patients
                                              • Includes all stages of CKD and all aspects of care
                                            • Vascular Access Guidelines most relevant to interventional procedures
                                              • Published 2006, update forthcoming January 2018

                                        PREPROCEDURE

                                        • Indications

                                          • Contraindications

                                            • Preprocedure Imaging

                                              • Getting Started

                                                PROCEDURE

                                                • Patient Position/Location

                                                  • Equipment Preparation

                                                    • Procedure Steps

                                                      • Findings and Reporting

                                                        • Alternative Procedures/Therapies

                                                          POST PROCEDURE

                                                          • Things to Do

                                                            • Things to Avoid

                                                              OUTCOMES

                                                              • Complications

                                                                • Expected Outcomes

                                                                  Selected References

                                                                  1. Vascular Access KDOQI Guidelines. Clinical practice guidelines for hemodialysis adequacy. http://www2.kidney.org/professionals/KDOQI/guideline_upHD_PD_VA/. Reviewed February 16, 2017. Accessed February 16, 2017
                                                                  2. Haskal ZJ et al: Prospective, randomized, concurrently-controlled study of a stent graft versus balloon angioplasty for treatment of arteriovenous access graft stenosis: 2-year results of the RENOVA study. J Vasc Interv Radiol. 27(8):1105-1114.e3, 2016
                                                                  3. Koirala N et al: Monitoring and surveillance of hemodialysis access. Semin Intervent Radiol. 33(1):25-30, 2016
                                                                  4. Sequeira A: Stent migration and bail-out strategies. J Vasc Access. 17(5):380-5, 2016
                                                                  5. Akoh JA et al: Review of transposed basilic vein access for hemodialysis. J Vasc Access. 16(5):356-63, 2015
                                                                  6. Balaz P et al: True aneurysm in autologous hemodialysis fistulae: definitions, classification and indications for treatment. J Vasc Access. 16(6):446-53, 2015
                                                                  7. Maytham GG et al: The use of the early cannulation prosthetic graft (Acuseal™) for angioaccess for haemodialysis. J Vasc Access. 16(6):467-71, 2015
                                                                  8. Quencer KB et al: Arteriovenous fistulas and their characteristic sites of stenosis. AJR Am J Roentgenol. 205(4):726-34, 2015
                                                                  9. Swinnen JJ et al: Paclitaxel drug-eluting balloons to recurrent in-stent stenoses in autogenous dialysis fistulas: a retrospective study. J Vasc Access. 16(5):388-93, 2015
                                                                  10. Vasanthamohan L et al: The management of cephalic arch stenosis in arteriovenous fistulas for hemodialysis: a systematic review. Cardiovasc Intervent Radiol. 38(5):1179-85, 2015
                                                                  11. Agarwal AK et al: How should symptomatic central vein stenosis be managed in hemodialysis patients? Semin Dial. 27(3):278-81, 2014
                                                                  12. Hart D et al: Modification of the HeRO graft allowing earlier cannulation and reduction in catheter dependent days in patients with end stage renal disease: a single center retrospective review. ScientificWorldJournal. 2014:318629, 2014
                                                                  13. Modabber M et al: Central venous disease in hemodialysis patients: an update. Cardiovasc Intervent Radiol. 36(4):898-903, 2013
                                                                  14. Samett EJ et al: Augmented balloon-assisted maturation (aBAM) for nonmaturing dialysis arteriovenous fistula. J Vasc Access. 12(1):9-12, 2011
                                                                  15. Bittl JA: Catheter interventions for hemodialysis fistulas and grafts. JACC Cardiovasc Interv. 3(1):1-11, 2010
                                                                  16. Haskal ZJ et al: Stent graft versus balloon angioplasty for failing dialysis-access grafts. N Engl J Med. 362(6):494-503, 2010
                                                                  17. Monroy-Cuadros M et al: Risk factors associated with patency loss of hemodialysis vascular access within 6 months. Clin J Am Soc Nephrol. 5(10):1787-92, 2010
                                                                  18. Allon M et al: Hemodialysis vascular access monitoring: current concepts. Hemodial Int. 13(2):153-62, 2009
                                                                  19. Whittier WL: Surveillance of hemodialysis vascular access. Semin Intervent Radiol. 26(2):130-8, 2009
                                                                  20. Casey ET et al: Surveillance of arteriovenous hemodialysis access: a systematic review and meta-analysis. J Vasc Surg. 48(5 Suppl):48S-54S, 2008
                                                                  21. Gelbfish GA: Clinical surveillance and monitoring of arteriovenous access for hemodialysis. Tech Vasc Interv Radiol. 11(3):156-66, 2008
                                                                  22. Mauro MA et al: Image-Guided Interventions. 1st ed. Philadelphia: Saunders, 2008
                                                                  23. Nassar GM: Endovascular management of the "failing to mature" arteriovenous fistula. Tech Vasc Interv Radiol. 11(3):175-80, 2008
                                                                  24. Rayner HC et al: Creation, cannulation and survival of arteriovenous fistulae: data from the Dialysis Outcomes and Practice Patterns Study. Kidney Int. 63(1):323-30, 2003
                                                                  25. Gallego Beuter JJ et al: Early detection and treatment of hemodialysis access dysfunction. Cardiovasc Intervent Radiol. 23(1):40-6, 2000