On the Retrograde Occlusive Arteriogram

Once thought to be a minor player in hemodialysis access dysfunction relative to outflow stenosis, perianastomotic (inflow) stenosis has recently come to be viewed as a major cause of arteriovenous fistula (AVF) problems (1–4). Indeed, recent literature has shown that a significant number of all accesses referred for dysfunction have an inflow lesion (1–3). Thus, imaging of the inflow segment of an AVF is critically important to a thorough evaluation of access dysfunction. Imaging of the inflow segment has been traditionally performed by interventional nephrologists via retrograde occlusive angiography (ROA). ROA is a technique by which contrast is injected into an arteriovenous access and made to flow retrograde because of the application of occlusive pressure on the outflow tract by the operator. This technique has traditionally been regarded as advantageous because it has been considered: (i) safe, (ii) effective, and (iii) easy to perform. The alternative technique of inflow imaging, whereby the operator would have to perform a second retrograde cannulation and manipulate a wire and a diagnostic catheter into the arterial system, does indeed seem most cumbersome by comparison at first glance. In this issue, Salman et al. (5) present an important contribution to our understanding of the ROA. They argue persuasively against the traditional view of the technique as a safe one. The authors present six cases of fistulae that suffered vascular rupture during ROA. In three cases, vascular damage occurred prior to the application of angioplasty. The remaining cases suffered perforation after angioplasty. Balloon tamponade was successful in salvaging two fistulae. Another AVFwith a perforation did not require any intervention to maintain flow. The complication was successfully managed in one AVF by the insertion of an endovascular stent graft. Two fistulae were lost as a result of vascular damage. This report demonstrates that ROA performed by occluding the outflow track of an AVF to assess the results of angioplasty of an inflow stenosis can result in vascular rupture, even without an antecedent angioplasty. The authors thus argue against ‘‘advantage number 1,’’ noted above—namely, that ROA is safe. Likewise, wemay ask ‘‘Is ROA really effective in evaluating the inflow of an arteriovenous access? ’’ This question was recently, though indirectly, addressed by the literature. It has been pointed out that the arteriovenous access represents a continuous circuit from the aortic arch, through the fistula or graft, and back to the right side of the heart (3). As such, any lesion in the central arteries represents an inflow problem that must be addressed by an interventionalist One particular limitation of the ROA in this context is that it only functions to image the immediate perianastomotic arterial system, entirelymissing a potential central arterial lesion. Perhaps even more salient is the observation that ROA is not particularly optimal in imaging even the perianastomotic inflow region. A recent case performed at our tertiary referral access center sheds some light on this issue. A 53-year-old man was referred for decreased fistula flow on routine monthly access evaluation. On physical exam, he had a weak pulse at the perianastomotic region with minimal augmentation on compression of the outflow tract, arguing for the presence of an inflow lesion (6). ROA was performed (Fig. 1) revealing no inflow lesion. Given the high suspicion of an inflow lesion supported by the physical examination findings. Adiagnostic catheter was navigated over a wire and advanced into the arterial system to perform a direct artriogram (Fig. 2). Expecting to find amore central inflow lesion, the operators were surprised by the presence of See ‘‘Retrograde Angiography and the Risk of Arteriovenous Fistula Perforation’’ by Salman, Asif, and Beathard in this issue.