1. A-V Fistula in HeamodialysisTechniques and ComplicationsDr- Saeed Al-ShomimiKing Faisal University Saudi Arabia2003

2. Introduction Definition Abnormal connection between artery and vein which bypasses capillary bed Aetiology congenital acquired:- surgically created for haemodialysis- penetrating trauma- iatrogenic eg following surgical dissection of artery, cannulation of artery or vein

3. Introduction The advent of hemodialysis in the early 1960 has provided longevity for many patients with CRF Quinton and his associates -> external A-V shunt 1963 , Shaldon -> femoral vien catheter

5. Blockage (thrombosis)

9. Anatomy

10. Anatomy

11. GENERAL PRINCIPLES OF ACCESS SURGERY

12. General Principles Preferable to use the arm vessels rather than the leg vessels When possible the non-dominant arm Access site should be placed as distally as practical in the limb , so that proximal sites will be available for subsequent procedures. 3. Inadequate or atherosclerotic arteries should be avoided , and a long section of patent vein is required to accommodate multiple cannulation site.

14. Subclavian or femoral catheter

15. External shunt

16. Peritoneal catheter required during the time that the permanent access are maturing prior to use.

17. General Principles Anticoagulation is not necessary during routine access operations , except for graft thrombectomy and revision procedures, or patients who do not have the usual hypocoagulable state of chronic renal failure. 8. Prophylactic antibiotics are used for all cases involving insertion of prosthetic material.

20. Intravenous cannulation

24. Illiac-femoral graft

28. Slightly lower fistula flow

30. Highest venous flow

31. Minimal venous hypertension

39. Procedures Side to side brachiocephalic fistula: When construction of fistula at the wrist is not possible , anastomosis of the cephalic vein to the brachial artery immediately proximal to the cubital fossa will provide satisfactory access A transverse incision is made proximal to the cubital fossa The brachial artery is mobilized untill it reaches the bifurcation at the level of bicipital tendon The median nerve lies medial and posterior to the artery and should be carefully protected The anastomosis is similar to the radiocephalic but the veenotomy and arteriotomy should be limited to about 5 – 7 mm to minimize the incidence of steal syndrome

40. Procedures Basilic vein – radial artery fistula: Mobilization of the basilic vein in the forearm and anastomosis of its end to the radial artery also may be used to provide access for heamodialysis The basilic vein is mobilized along the ulner border of the forearm to about the middle of the forearm. A subcutanious tunnel is prepared between the vein and the radial artery These vessels are then anastomosed attaching the vein end to either the end or the side of the artery

41. This technique of fistula formation may be used in patients who have an obliterated cephalic vein or distal radial artery It is possible to anastomose the basilic vein to the ulner artery, however if there has been a previous radiocephalic fistula in that arm , there is a danger that circulation in the hand will be compromized

43. Complications

46. A sclerotic vein segment in the forearm because of previous venisection

47. Inadequate venous size

49. complications Aneurysm: Pseudoaneurysm formation may occur at puncture sites following dialysis However , the incidence is much lower than that of prosthetic grafts True aneurysm are much rare but have also been reported in few occasions in the vein distal to the anastomosis These can be treated with resection and either end to end anastomosis Placement of short segment graft

51. complications Infection: Infection of autogenous fistula are rare compared to prosthetic graft They present with: Fever Erythema Tenderness And complications (such as thrombosis and aneurysm ) The most common infecting organism is staph aureus Managed by systemic antibiotics , drainage and revision as necessary

52. complications Ischemic changes: Steal symptoms may occur in around 4% of patients with autogenous fistula The incidence is higher in : Diabetic patients Atherosclerotic patients And in anticubital fistulas The symptoms may only manifested during dialysis and as such may be managed by observation and by using low flow rate At its worst , gangrene may occur requiring amputation To avoid the problem of retrograde flow through the palmar arch in wrist fistula , ligation of the radial artery distal to the anastomosiscan be performed . Alternatively an end to end anastomosis can be constructed

54. complications Venous hypertension: Another vascular complication is the development of venous hypertension syndrome , where the hand distal to the fistula become swollen and uncomfortable with thickning of the skin and hyperpigmentation Venous hypertension may be avoided by forming an end to end anastomosis Or to ligate the enlarged venous tributaries causing the hypertension of the distal digits , so preserving the fistula

55. complications Cardiovascular complication: High output cardiac failure is a rare complication which may occurs particularly in patients displaying a combination of low heamatocrit, cardiomyopathy from diabetes and the presence of high flow fistula Treatment usually involves sacrificing the fistula

56. Care of A-V Fistula Keep the fistula arm raised on a pillow to reduce swelling. The dressing should remain intact and dry at all times. As soon as post operative pain has subsided, start arm exercises Do not allow blood pressure, blood taking or intravenous administration on the fistula arm. Check for thrill

58. Thank you