RESUMO
We describe the phenomenon of coronary artery "pseudo-occlusion," which may occur when active hemoperfusion devices are utilized during percutaneous transluminal coronary angioplasty (PTCA). In such cases, contrast injected via the guiding catheter fails to opacify the coronary artery distal to the tip of the dilating catheter, thereby giving the angiographic appearance of coronary occlusion. When active hemoperfusion is terminated, contrast opacifies the vessel in a normal fashion. The cause of this observation is likely multifactorial and includes obstruction to flow by the dilating catheter, high distal pressure delivered by the dilating catheter during hemoperfusion competing with the flow of contrast injected via the guiding catheter, and wash-out of contrast at the tip of the dilating catheter by non-contrast containing blood being pumped through the system. This phenomenon must be recognized if potentially deleterious repeat dilatations are to be avoided.
