Covered Stents in the Treatment of Pulmonary Arteriovenous Malformations
Figure 1. (a) Selective right upper lobe pulmonary arteriogram shows PAVM before initial treatment. Note very short communication (arrowhead) between the pulmonary artery (containing catheter) and draining vein (arrow). Note also the large normal pulmonary vascular bed distal to PAVM. (b) Selective right upper lobe pulmonary arteriogram after coil embolization shows occlusion of PAVM. (c) Selective right upper lobe pulmonary arteriogram obtained at follow-up shows recanalized PAVM with prompt arteriovenous shunting (arrowhead shows draining vein). Note very short remaining vessel between catheter tip and coil nest (arrow). (d) Oblique view with catheter tip in the vessel that previously received embolization again shows pronounced shunting with prompt filling of draining vein (arrow). Digitally subtracted (e) and native (f) images after placement of a covered stent (arrows) show good position and exclusion of the feeding artery with no further flow into PAVM. The parent vessel is well preserved. (g) Coronally reformatted image from computed tomography arteriogram obtained 55 months after the procedure shows a patent covered stent with resolution of PAVM.
This article demonstrates a novel approach to treating an uncommon entity (pAVM) of a rare disease (HHT) with an emphasis on the preservation of normal pulmonary vasculature in patients who often require multiple treatments throughout their lives. Interestingly, despite the small size of these vessels, the stents remained patient without the use of anticoagulant or antiplatelet medications. In one instance, a separate study reported patency at 120 months without recanalization or persistence of the treated AVM. Pulmonary AVMs are seen nearly entirely in patients with hereditary hemorrhagic telangiectasia and stent-graft exclusion of these lesions is an infrequent treatment approach, which explains the small sample size limitation of this study. However, the particular predilection of pAVMs for patients with HHT raises the question of whether or not their unique genetic makeup and biochemistry helps prevent stent occlusion. While confident use of stent grafts for this purpose requires additional research with long-term follow up, consideration may be given to using these more liberally as they are impermeable to flow and should theoretically eliminate the possibility of recanalization of the treated feeder vessels. They also carry the added benefit of easier follow-up with chest CTA as they do not produce any significant imaging artifact. Finally, a cost based analysis may be warranted to ascertain whether universal use of stent-grafts is financially feasible or should be reserved for complex interventions like those in this study.
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Harrison X. Bai, MD, Reed E. Pyeritz, MD, and Scott O. Trerotola, MD. Covered Stents in the Treatment of Pulmonary Arteriovenous Malformations. J Vasc Interv Radiol 2018; 29:981–985
Caleb L. Mills, MD PGY-4
Department of Radiology
Wake Forest Baptist Medical Center