Invited commentary

Abstract

This study from the University of Pittsburgh addresses an important clinical problem after hemodialysis access creation: the ischemic steal syndrome (ISS). It is one of the largest series in the literature.1Gupta N. Yuo T.H. Konig G. Dillavou E. Leers S.A. Chaer R.A. et al.Treatment strategies of arterial steal after arteriovenous access.J Vasc Surg. 2011; 54 (in press)Google Scholar The pathophysiology of ISS is worth reviewing. The magnitude of blood flow through an arteriovenous fistula is a function of the diameter of both the fistula and the donor artery. Fistulas are classified by the fistula diameter relative to that of the donor artery. Small fistulas are defined as having a diameter <75% of the diameter of the inflow artery. In small fistulas, the primary determinant of the magnitude of fistula flow is fistula resistance, which varies with the fourth power of the diameter. The natural history of small fistulas is thrombosis. Large fistulas have a diameter >75% that of the donor artery, and the magnitude of blood flow tends to be independent of fistula resistance and diameter. In large fistulas, flow is determined primarily by the relative resistances of the peripheral vascular bed, the donor artery, and the collateral circulation. Most surgically created fistulas are of the large variety in order to provide sufficient blood flow (approximately 600 ml/minute) for dialysis.2Wixon C.L. Hughes J.D. Mills J.L. Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access.J Am Coll Surg. 2000; 191: 301-310Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar, 3Wixon C.L. Mills J.L. Berman S.S. Distal revascularization-interval ligation for maintenance of dialysis access and restoration of distal perfusion in ischemic steal syndrome.Sem Vasc Surg. 2000; 13: 77-82PubMed Google Scholar Nearly all surgically created fistulas create physiological steal; ISS results when distal arterial perfusion is inadequate to meet tissue metabolic requirements.2Wixon C.L. Hughes J.D. Mills J.L. Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access.J Am Coll Surg. 2000; 191: 301-310Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar Thus, it is no surprise that banding, which increases fistula resistance, is unlikely to achieve the dual goals of ISS treatment (ie, preservation of the access and relief of the ischemia). In this series, banding had poor outcomes. Nineteen percent of fistulas thrombosed after banding, and 48% of patients had persistent ischemia; 73% of reinterventions were performed in patients who underwent banding. Distal revascularization and interval ligation (DRIL) had a statistically better success rate than banding (P ≤ .05) and was effective in resolution of ISS in 90% of patients. DRIL remains the procedure of choice for treatment of ISS.4Knox R.C. Berman S.S. Hughes J.D. Gentile A.T. Mills J.L. Distal revascularization-interval ligation: a durable and effective treatment for ischemic steal syndrome after hemodialysis access.J Vasc Surg. 2002; 36: 250-256Abstract Full Text PDF PubMed Scopus (153) Google Scholar I would urge future investigations of ISS to include hemodynamic data (digital arterial pressure measurements with and without fistula compression), which in my view, are essential to confirm the diagnosis and quantify severity.2Wixon C.L. Hughes J.D. Mills J.L. Understanding strategies for the treatment of ischemic steal syndrome after hemodialysis access.J Am Coll Surg. 2000; 191: 301-310Abstract Full Text Full Text PDF PubMed Scopus (124) Google Scholar While hemodynamic data were not routinely collected in this series, it is interesting to compare pre- and postoperative hemodynamics for those in whom they were available. Following the DRIL procedure, digital pressures increased from 43 to 75 mm Hg; after banding, the corresponding increase was only from 33 to 44 mm Hg. This difference was statistically significant and likely accounts for the failure of a substantial number of banded patients to improve. The authors report some experience with revision using distal inflow (RUDI) and proximalization of arterial inflow (PAI). While the reported results were excellent, patient numbers were low. These procedures likely work in a manner analogous to the DRIL procedure, by altering relative resistances (either by adding length or reducing donor artery diameter) rather than by increasing fistula outflow resistance. Such procedures, based on the physiology of ISS, are most likely to succeed. This is a well-written study of ISS. Hopefully, it will lay banding to rest. Future investigations, especially with the newer RUDI and PAI procedures, should include hemodynamic data and sufficient follow-up to allow comparison with the well-established DRIL procedure. Treatment strategies of arterial steal after arteriovenous accessJournal of Vascular SurgeryVol. 54Issue 1PreviewIschemic steal syndrome (ISS) associated with arteriovenous (AV) access is rare but can result in severe complications. Multiple techniques have been described to treat ISS with varying degrees of success. This study compares the management and success associated with these techniques. Full-Text PDF Open Archive