Interventions for AVF and AVG Stenosis

Both surgery and interventional procedures are established treatments for stenosis in patent and thrombosed AVF1. The 2006 KDOQI hemodialysis access working group recommends that a hemodynamically significant stenosis requiring intervention should display a ≥50 percent stenosis (as determined radiographically) plus evidence of a clinical or physiologic abnormality such as elevated venous pressure or decreased blood flow2,3. In recent years, endovascular techniques have tended to supplant traditional surgery at many centers1. Percutaneous therapies including angioplasty, percutaneous thrombectomy, the use of stents, and thrombolytics have made access repair easier, more successful, less invasive and readily available on an outpatient basis4. Although there have been few recent direct comparisons between percutaneous transluminal angioplasty (PTA) and surgical revision, uncontrolled studies have reported that PTA has a greater than 95% success rate5. This success rate combined with superior convenience and less morbidity compared with surgery has resulted in increasing usage of PTA therapy for stenotic lesions5.

Percutaneous angioplasty and surgical revision each have advantages and disadvantages. The major advantages of surgery for venous stenosis are the elimination of the lesion and potentially lower recurrence rates. The major disadvantages are the loss of potential venous access sites and the significant burden logistically and physically imposed by surgery. Even a patch angioplasty, for example, results in the loss of a small portion of vein. Since venous stenosis is a recurrent problem, this may result in a progressive loss of venous anatomy available for access creation2. Percutaneous angioplasty has the principal advantage of preserving potential venous access sites; however, severe lesions (>80% of lumen) may require surgical revision2. See table below.

Characteristics of AVF stenosis intervention modality2

Percutaneous angioplasty Surgical revision
Outpatient procedure x
Access immediately available for dialysis once the lesion is corrected x
Lesions in all locations, even those centrally located, can be easily, effectively, and safely treated x
Preserves potential venous access sites x
Minimally invasive x
Elimination of the lesion x
Effective for severe lesions (>80% of lumen) x
Loss of potential venous access sites x
Minimal post procedure discomfort x
Occasional need for a temporary access x
Inaccessibility of central veins to the surgeon x
Lesions tend to be recurrent x x

 

Although PTA corrects over 80% of stenoses in both native fistulae and synthetic grafts and in both venous and arterial outflow tracts2, several studies have suggested that angioplasty outcomes may be inferior to surgical therapy4. The rationale for this view is that underlying pseudointimal hyperplasia causing stenosis may rapidly recur post angioplasty4. Though some studies have lauded the efficacy of surgical treatment, others question it. In a 2002 surgical study conducted over a two year period, 101 operative procedures were performed on failed grafts in which all cases had previously been treated with percutaneous dilatation2,6. Primary patency rates of grafts following surgical revision were 43, 24, and 12 percent at 30, 60, and 90 days, respectively2,6. These surgical investigators concluded that surgical intervention did not significantly prolong the patency of grafts that had previously failed percutaneous interventions2,6. However, a 2008 study by Crikis found that surgery achieves superior patency rates compared to repeated radiological interventions and should be considered if reocclusion occurs within a month following radiological thrombolysis7.

The rapid development and widespread use of new technologies (thrombolytics, specialized guide wires, angioplasty catheters and balloons, stents, covered stents, digital imagining, ultrasound, etc.) has made interpreting the literature more difficult4. In this changing environment, outcome and trials data may quickly become outdated and result in the use of therapies based primarily on experience, expedience and practice patterns4.

References

  1. Lipari G, Tessitore N, Poli A, Bedogna V, Impedovo A, Lupo A and Baggio E. Outcomes of surgical revision of stenosed and thrombosed forearm arteriovenous fistulae for haemodialysis. Nephrol Dial Transplant 22:2605-2612, 2007
  2. Beathard, GA. Percutaneous angioplasty for the treatment of venous stenosis affecting hemodialysis access grafts. Retrieved from www.uptodate.com on February 23, 2009
  3. KDOQI Clinical Practice Guidelines for Vascular Access. Am J Kidney Dis 48(Suppl 1):S176-S273, 2006
  4. Sands JJ. Vascular access 2007. Minerva Urol Nefrol 59:237-249, 2007
  5. Beathard GA. Early and late hemodialysis arteriovenous fistula failure. Retrieved from www.uptodate.com on February 23, 2009
  6. Alexander J, Hood D, Rowe V, Kohl R, Weaver F, Katz S. Does surgical intervention significantly prolong the patency of failed angioaccess grafts previously treated with percutaneous techniques? Ann Vasc Surg 16:197-200, 2002
  7. Crikis S, Lee D, Brooks M, Power DA, Ierino FL, Levidiotis V. Predictors of early dialysis vascular-access failure after thrombolysis. Am J Nephrol 28:181-189, 2008

P/N 101049-01 03/2009