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Tamer elsaid mansouraoct2019
The document discusses strategies for salvaging failing vascular access in hemodialysis patients through techniques like balloon angioplasty and stent placement. It outlines the complications associated with vascular access and guidelines for monitoring access. Examples are provided of endovascular interventions performed to treat stenoses in arteriovenous fistulas and grafts.
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Tamer elsaid mansouraoct2019
- 1. Vascular Access Salvage: NephrologyPerspective Tamer ElSaid, MD Ain Shams University
- 2. The Problem! • Steadyincrease in no. of ESRD patients requiring RRT (usually being Hemodialysis). • We need an adequate vascular access (VA) to be able to deliver this extracorporeal blood purification treatment (HD) • VA and it’s associated complications, constitute the most common cause of morbidity, hospitalization, and cost among those patients
- 3. Complications of hemodialysis vascularaccess 1.Stenosis 2.Thrombosis 3.Aneurysmal formation. 4.Venous hypertension 5.Infection 6.Steal phenomenon 7.Heart failure
- 4. Monitoring and Surveillanceof VA! Monitoring • This term refers to the examination and evaluation of the vascular access by means of physical examination to detect physical signs that would suggest the presence of pathology. Surveillance • This term refers to periodic evaluation of the vascular access by means of tests, which may involve special instrumentation, for which an abnormal test result suggests the presence of pathology. Diagnostic Testing • This term refers to testing that is prompted by some abnormality or other medical indication and which is undertaken to diagnose the presence of pathology (i.e.,angiography).
- 5. Prospective Diagnosis ofVenous Stenosis NKF-K/DOQI Clinical Practice Guideline 4 4.1 Physical examination (monitoring): • Physical examination should be used to detect dysfunction in fistulae and grafts at least monthly by a qualified individual 4.2 Surveillance of grafts: • Techniques, not mutually exclusive, that may be used in surveillance for stenosis in grafts include: • 4.2.1 Preferred: • o 4.2.1.1 Intra-access flow by using 1 of several methods that are available, using sequential measurements with trend analysis. • o 4.2.1.2 Directly measured or derived static venous dialysis pressure by 1 of several methods that are available • o 4.2.1.3 Duplex ultrasound • 4.2.2 Acceptable: • o 4.2.2.1 Physical findings of persistent swelling of the arm, presence of collateral veins, prolonged bleeding after needle withdrawal, or altered characteristics of pulse or thrill in a graft • 4.2.3 Unacceptable: • o 4.2.3.1 Unstandardized dynamic venous pressures should not be used.
- 6. 4.3 Surveillance infistulae: • Techniques, not mutually exclusive, that may be used in surveillance for stenosis in AVFs include: • 4.3.1 Preferred: • o 4.3.1.1 Direct flow measurements • o 4.3.1.2 Physical findings of persistent swelling of the arm, presence of collateral veins, prolonged bleeding after needle withdrawal, or altered characteristics of pulse or thrill in the outflow vein • o 4.3.1.3 Duplex ultrasound • 4.3.2 Acceptable: • o 4.3.2.1 Recirculation using a non–urea-based dilutional method • o 4.3.2.2 Static pressures, direct or derived
- 7. The Main GoalIn Managing A Failing VA! “Prospective Diagnosis of Venous Stenosis” • It is important that all hemodialysis facilities have in place a system designed to detect venous stenosis so that it can be diagnosed and treated prospectively
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- 9. Physical Examination • Look –Well-developed main venous outflow – Collateral venous effluent vessels – Collapses or softens when arm is raised • Listen – Low-pitched continuous systolic-diastolic bruit • Feel – Gentle thrill at the arterial anastomosis – Should NOT be hyperpulsatile
- 10. Intra-access Pressures Static venouspressure: Pia/MAP at venous outlet >0.35 (for AVF) and >0.5 (for AVG)
- 11. ‘Standardized’ Dynamic Venous Pressure Determinantsof Dynamic Venous Pressure • Pressure within the access (this is an asset) • Pressure related to the resistance created by the system (this is a liability) - Venous return blood tubing - Any constriction in the system - Venous return needle (gauge) - Hematocrit (viscosity of blood) “Dynamic venous pressure: >120 (with needle gauge 15) and >150 (with needle gauge 16)”
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- 13. Possible sites ofstenosis in relation to clinical findings & physical exam Clinical findings Physical examination Possible sites of stenosis High dynamic or static venous pressure Pulsatile AVF Outflow stenosis Prolonged bleeding after removal of dialysis needle Pulsatile AVF Outflow stenosis Upper limb swelling Swollen arm Central vein stenosis Decreased thrill Flat AVF Inflow stenosis and body Difficult cannulation Flat or difficult to palpate Good thrill Inflow stenosis and body No stenosis, AVF too deep for cannulation Failure to mature Flat AVF Multiple dilated veins Inflow stenosis Presence of accessory veins or collaterals
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- 16. • Angiogram - Identifiesanatomic abnormalities - Allows for pre-emptive percutaneous interventions (e.g. angioplasty and/or stent placement) - Guides surgical intervention Finally ‘Test’ to evaluate!
- 17. Juxta-anastomotic stenosis; A –fistula, B – radial artery, C – anastomosis, D - area of stenosis
- 18. AV access salvage •Balloon angioplasty for short segment of stenosis (inflow, intra-access, outflow) • Balloon angioplasty/stenting for central vein stenosis • Mechanical thrombectomy or pharmacologic thrombolysis • Graft interposition for long segments of stenosis • Ligation of side branches/stealing branches • Covered stents or resection for aneurysms
- 19. Juxta-anastomotic stenosis (before andafter angioplasty)
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- 23. Radiation safety (Leadeprons)
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- 26. CANNULATION NEEDLES • 18Gauge Thin Walled Introducer Needle
- 27. • Micropuncture Needle(This is a 21-gauge needle that allows for the passage of a guidewire (0.018 inch in diameter) followed by a compound (two-step) dilator. The dilator is of double construction. It consists of a 3 French dilator which is tapered to 0.018 inch that is inside and extends beyond the tip of a 5 French one which is tapered to 0.035 inch.)
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- 29. GUIDEWIRES • Basic Guidewire Construction Standard Diameter: 0.35 inche
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- 32. Short vascular sheath(4cm) “Note color tag!”
- 33. “Note – Mostof the devices used in the interventional lab are measured using a unit of measure called a French. There are 2.8 French in a millimeter. Actually, it is useful to think in terms of 3 French to the millimeter. In other words, a 9 French dilator is approximately 3 mm in diameter (to be precise it is 3.14 mm).
- 34. Guiding catheters 1 –Straight catheter, 2 – Hockey stick catheter, 3 – Hooked catheter, 4 - Cobra catheter
- 35. • Hooked (RIM)catheter used to direct guidewire into branch of vessel that comes off at a severe angle
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- 38. Balloon mounted ORSelf Expandable
- 39. Stents and Stentgrafts
- 40. Contrast media andCO2 angiogram
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- 43. Differences between arterialand venous interventions during dialysis access management
- 44. Fundamentals of Venousintervention as compared to Arterial intervention Venous intervention Arterial intervention Heparin Usually not required Usually required Complications Rupture, thrombosis, pulmonary embolism Dissection, thrombosis, rupture Balloon length Oversize Cover lesion and little beyond Balloon diameter Oversize Do not oversize Duration of inflation Long (min 3 min) Short Type of balloon High pressure balloon Choice depends on type of lesion
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- 47. 1- Cannulation. 2- Sheathplacement. 3- Venography. 4- Retrograde angiography. 5- Pass guidewire. 6- Sedation. 7- Balloon angioplasty. 8- Re-venography -----judge success & complications. 9- Remove the sheath. 10- Physical examination. . STEPS
- 48. Indications for stentplacement 1. Central vein stenosis where there is acute elastic recoil of the vein (>50%) after angioplasty OR recurrence of stenosis within 3 months period. 2. angioplasty induced vascular rupture, patients with surgically inaccessible lesion, or contraindication to surgery
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- 50. (A) Pull backangiogram showing subclavian vein 80% stenosis (arrows). Case 1:55 years old female with pulsatile left arm graft.
- 51. (B) 10 mm.balloon inflated within the stenotic lesion (arrow).
- 52. (C) Post- angioplastyrevealing < 30% residual stenosis (arrow).
- 53. (A) Retrograde fistulogramrevealing > 90% stenosis (arrow) at the arterial anastomosis. Case 2:52 years old female with difficult puncture of her left AV fistula.
- 54. (B) 5 mm.balloon inflated (arrows) within the stenotic lesion.
- 55. (C) Post angioplastywith < 30% residual stenosis (arrow).
- 56. (A) Fistulogram revealingcomplete occlusion of the right subclavian vein (black arrows) with multiple superficial collaterals (white headed arrows). Case 3: 75 years old female with malfunctioning right arm AV graft, on examination the right arm was swollen, and multiple superficial collaterals were seen on the right side of the chest wall.
- 57. (B) 9 mm.balloon inflated (arrows) within the stenotic lesion. . .
- 58. (C) Fistulogram revealingno flow even after angioplasty so decision of stent placement was taken. .
- 59. (D) 10 mm.balloon inflated within 10 x 80 mm. covered stent (arrows).
- 60. (E) Angiogram wasdone after deploying the stent, and showed partial opening of the central vein. Decision was done to put another stent in the axillary vein overlapping the proximal stent because there were some clots in that area.
- 61. (F) Second 10x 80 mm. stent (stent 2) deployed within the axillary vein overlying the first stent.
- 62. (G) Angiogram revealingcomplete restoration of flow in the central veins with no collaterals.
- 63. (A) Fistulogram revealed80% venous stenosis at the venous anastomosis (arrow) Mechanical thromboaspiration was done and revealed multiple clots. Case 4: 74 years old female patient with clotted left arm AV graft. On examination the graft thrombus was felt with weak thrill felt over..
- 64. (B)8 mm. angioplastyballoon inflated within the stenotic lesion (arrows).
- 65. (C) Post-angioplasty andmechanical thromboaspiration fistulogram revealing < 30% residual stenosis (arrows).
- 66. (D) In thesame case, a thrombus plug (filling defect) was seen at the arterial anastomosis (arrow).
- 67. (E) Fistulogram afterusing Fogarty catheter to pull out the arterial plug…no filling defects left (arrows).
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