1. GRAFT Thrombosis: Recent trends in Management

2. Introduction
Most patients with end-stage renal disease undergo hemodialysis thrice weekly to
Optimize their survival
Minimize medical complications and
Enhance their quality of life
A reliable vascular access is a
Critical requirement for providing adequate hemodialysis

3. Introduction The ideal vascular access would be Easy to place
Ready to use as soon as it is placed,
Deliver high blood flows indefinitely, and
Free of complications
None of the existing types of vascular access achieves this ideal
Among the three types of vascular access currently available,
Native arteriovenous (AV) fistulas are superior to AV grafts, which, in turn, are superior to dialysis catheters

4. Introduction
Recognizing the relative merits of the vascular access types, the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines recommend placement of
AV fistulas in at least 50% of hemodialysis patients,
AV grafts in 40%, and
Dialysis catheters in no more than 10%

5. Loop Forearm Graft, Venous Preparation

6. SPECIFIC CRITERIA PTFE A-V Graft
Autologous options have been considered / excluded / exhausted
(Exception : graft first may preserve future options)
Absence of Collagen Vascular Disease (Lupus Nephritis)
Generally, forearm before upper arm
(Exception : secondary upper arm graft on non-dominant side)
Superficial vein target preferable to deep vein
Min diam of venous target >4.5 mm, min length > 16 mm
Success upper arm graft limited if diam < 5 mm
Arterial target diam > 3.5 mm (4.0 mm upper arm)
Consider 5 mm graft
Consider crossing joint

7. Introduction
Vascular access procedures and their subsequent complications represent a major cause of
Morbidity,
Hospitalization, and
Cost for chronic hemodialysis patients

8. AV grafts AV grafts are prone to Recurrent stenosis and thrombosis and
Require multiple radiologic or surgical interventions to ensure their long-term patency for dialysis

9. AV graft thrombosis About 80% of graft failures are due to thrombosis
Thus, improving graft longevity requires implementing measures to reduce the frequency of graft thrombosis
When grafts are referred for thrombectomy, a significant underlying stenosis is observed, most commonly at the venous anastomosis, the draining vein, or the central veins
This observation suggests that
Prophylactic angioplasty of hemodynamically significant graft stenosis may reduce the frequency of graft thrombosis, and thereby increase cumulative graft survival

10. AV graft thrombosis
Thrombosed grafts usually have an underlying stenosis,
most commonly at the venous anastomosis or in the draining vein
Salvage of clotted grafts requires
Thrombectomy as well as
Angioplasty or surgical revision of the underlying stenosis

11. AV graft thrombosis
However, the primary patency (intervention free survival) is considerably worse after treatment of clotted grafts, as compared with
Elective angioplasty of patent grafts with stenosis
After elective angioplasty, the primary graft patency is
70 to 85% at 3 mo and 47 to 63% at 6 mo
In contrast, after thrombectomy and angioplasty of clotted grafts, the primary patency is only
33 to 63% at 3mo and 11 to 39% at 6 mo

12. AV graft thrombosis
Comparison of outcomes of 656 radiologic graft interventions performed at a single dialysis center found a 3-mo primary patency of
71% after elective angioplasty, as compared with
30% after treatment of clotted grafts
Am J Kidney Dis 2001;37: 945–953

13. AV graft thrombosis
Given the dismal outcomes of clotted grafts, it would be desirable to
Identify prospectively grafts that are at risk for thrombosis and intervene prophylactically to prevent the graft from clotting
Because graft thrombosis is usually superimposed on hemodynamically significant stenosis, it is a plausible hypothesis that timely detection and correction of the stenosis will prevent graft thrombosis
Clin J Am Soc Nephrol 2007;2: 786–800

14. AV graft thrombosis Achieving this goal requires having a Simple Cheap
Reproducible, and
Sensitive method to
Monitor for graft stenosis
Clin J Am Soc Nephrol 2007;2: 786–800

15. Mechanical Interventions to Reduce Graft Thrombosis
Approaches for detection of graft stenosis
Clinical monitoring consists of physical examination (absent thrill, abnormal bruit, or distal edema),
Abnormalities identified during dialysis sessions
Prolonged bleeding from needle sites or
Difficulty in cannulation), or
An unexplained decrease in Kt/V on a constant dialysis prescription
Clin J Am Soc Nephrol 2007;2: 786–800

16. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
AVGs have the following advantages:
A large surface area and vessel available for cannulation initially
They are technically easy to cannulate
The lag-time from insertion to maturation is short
For PTFE-derived grafts, it is recommended that not less than 14 days should elapse before cannulation to allow healing and incorporation of the graft into local tissues, although ideally, 3 to 6 weeks are recommended
Multiple insertion sites are available

17. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
AVGs have the following advantages:
A variety of shapes and configurations is available to facilitate placement
It is easy for the surgeon to handle, implant, and construct the vascular anastomosis
The graft is comparatively easy to repair either surgically or endovascularly

18. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
The sum of the available data, until recently, supported PTFE grafts over other biological and other synthetic materials, based on
lower risk for disintegration with infection, longer patency, better availability, and improved surgical handling
Biological grafts (bovine heterografts) have greater reported rates of complications compared with synthetic grafts

19. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
For nearly 2 decades,
PTFE has been the material of choice for bridge grafts.
However, during the past decade, modifications and the use of other materials, such as PU, cryopreserved femoral vein, bovine mesenteric vein, and hybrids with self-sealing composite material, have been developed and used
None of these has shown any “survival” patency over plain PTFE, except for the composite/PU graft

20. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
Composite/PU graft
Has an advantage because of its self-sealing property to be cannulated within hours, if needed, for dialysis
As a result, it can be placed without having to use a catheter for initiation of dialysis therapy, in some cases
Direct comparisons between PTFE and human umbilical cord vein grafts and other synthetic polymers have not been made

21. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
Treatment of thrombosis and associated stenosis: Each institution should determine which procedure, percutaneous thrombectomy with angioplasty or surgical thrombectomy with AVG revision, is preferable based upon expediency and physician expertise at that center.
6.7.1 Treatment of AVG thrombosis should be performed urgently to minimize the need for a temporary HD catheter. (B)
6.7.2 Treatment of AVG thrombosis can be performed by using either percutaneous or surgical techniques. Local or regional anesthesia should be used for the majority of patients. (B)
6.7.3 The thrombectomy procedure can be performed in either an outpatient or inpatient environment. (B)

22. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
6.7.4 Ideally, the AVG and native veins should be evaluated by using intraprocedural imaging. (B)
6.7.5 Stenoses should be corrected by using angioplasty or surgical revision. (B)
6.7.6 Methods for monitoring or surveillance of AVG abnormalities that are used to screen for venous stenosis should return to normal after intervention. (B)

23. NKF KDOQI GUIDELINES 2006 Updates Vascular Access
Outcomes after treatment of AVG thrombosis: After percutaneous or surgical thrombectomy, each institution should monitor the outcome of treatment on the basis of AVG patency. Reasonable goals are as follows:
6.8.1 A clinical success rate of 85%; clinical success is defined as the ability to use the AVG for at least 1 HD treatment. (B)
6.8.2 After percutaneous thrombectomy, primary patency should be 40% at 3 months. (B)
6.8.3 After surgical thrombectomy, primary patency should be 50% at 6 months and 40% at 1 year. (B)

24. Clin J Am Soc Nephrol 2007;2: 786–800

27. Clin J Am Soc Nephrol 2007;2: 786–800

28. Options for treating steal
DRIL procedure
distal revascularization- interval ligation
excision of a portion of the vein
plication w/ mattress or continuous sutures
crossed PTFE band
interposition of a 4 mm PTFE

29. Treatment of venous access complications.
Venous angioplasty
Graft thrombolysis

30. Contraindications to Thrombolytic Therapy
Absolute  
  Recent major bleeding   Recent stroke   Recent major surgery or trauma   Irreversible ischemia of end organ   Intracranial pathology   Recent ophthalmologic procedure
Relative   
History of gastrointestinal bleeding or active peptic ulcer disease   Underlying coagulation abnormalities   Uncontrolled hypertension   Pregnancy   Hemorrhagic retinopathy

31. Recent articles
Patency rate and complications of polytetrafluoroethylene grafts compared with polyurethane grafts for hemodialysis access.
RESULTS:
One-year patency rate was reported to be 64% and 52% in the PTFE and PVAG groups, respectively. There was no significant difference in 1-year (64% versus 52%) and 2-year (49% versus 41%) patency rate of the PTFE and PVAG grafts used as vascular access. There was also no difference between the numbers of complications reported in the two groups.
CONCLUSION:
It could be concluded that either PTFE or PVAG grafts can be used with the same expected outcomes
Ups J Med Sci Nov;115(4):245-8

32. Long-term Outcome of a Cuffed Expanded PTFE Graft for Hemodialysis Vascular Access
Compared to the standard ePTFE, the cuffed ePTFE graft provided better long-term outcome, especially in terms of secondary patency rates after radiological intervention
World Journal of Surgery Volume 32, Number 8,

33. Balloon Angioplasty Versus Surgical Revision for Thrombosed Dialysis Graft Outlet Stenosis After Graft Thrombectomy
The result of dialysis graft outlet balloon angioplasty was comparable to that of surgical revision. Considering the invasiveness, balloon angioplasty should be considered when treating thrombosed dialysis grafts.
ANGIOLOGY August 2010; 61 (6):

34. LifeSite ®
12 F. Catheter
Multi-side-hole tip

35. Thank You!