The Pronto Catheter: Distal Embolization of Any Remaining Thrombus Fragments May Be a Risk of Creating and Then Removing Negativ

In patients presenting with an acute coronary syndrome, intracoronary thrombus removal is often required during percutaneous coronary intervention. The Pronto (Vascular Solutions, Inc., Minneapolis, Minnesota) catheter is a hydrophilically-coated dual-lumen catheter designed for the removal of fresh, soft emboli and thrombi from vessels in the arterial system. While the smaller-wire lumen accommodates the guidewire, the larger extraction lumen allows for removal of thrombus by using the syringe through the extension line and stopcock. The Pronto uses simple vacuum suction and has been described as a quick and simple tool for the management of thrombus in the setting of acute myocardial infarction.^1,2 Although certain precautions and warnings have been stated in the instructions for use, the importance of maintaining suction during the entire procedure is not mentioned. We believe that maintaining negative pressure once the extraction of thrombus has been started is of critical importance until the process is completed. The instructions state that blood will enter the syringe until all the vacuum is gone. The next step is to turn the stopcock to the “off” position. This has a two-fold effect: apart from closing the syringe from the vessel lumen, this step also cancels the vacuum that had until then, extracted the thrombus. With such loss of negative pressure, the remaining thrombus in the vessel is free to embolize with no vacuum holding it. This is crucially important with large thrombi. We believe that this potential to cause distal embolization of any remaining fragments of thrombus in the artery, underscores the need for a constant negative pressure to be maintained by the device until the entire thrombus has been extracted. Investigation into overcoming this risk, with emphasis on preventing potential embolic complications by creating and then removing suction, is warranted to improve the safety of this novel percutaneous intracoronary thrombectomy system. Aspirating the guide catheter after removing the Pronto is a way to decrease the risk of embolization of any distal thrombus fragments in our experience, and this could be added to the deployment steps in the instructions.