Hydrophilic Polymer in Thrombus Specimens Obtained During Thrombus Aspiration in the Setting of Percutaneous Interventions in Japan

Although hydrophilic polymer (HP) is used on vascular catheters to prevent medical device–related complications, HP emboli are well established as a potentially fatal iatrogenic phenomenon. HP embolus is thromboembolism by HP, which is mechanically disrupted from catheter during procedure. We reviewed 119 thrombus specimens obtained by percutaneous interventions from the coronary artery, vessels of inferior and superior limbs, cerebral artery, carotid artery, and renal vein. The frequency of HP was 28.6% (34/119 cases); 26.4% (24/91 cases), coronary artery; 50% (6/12 cases), artery of the lower limb; 28.6% (2/7 cases), vein of the lower limb; 0% (0/2), artery of the upper limb; 33.3% (1/3 cases), cerebral artery; 50% (1/2 cases), pulmonary artery; 0% (0/1 case), carotid artery; and 0% (0/1 case), renal vein. The range of numbers and diameter of HP was 1 to 127 per case and 10 to 934 µm, respectively. This is the first study concerning HP in thrombus specimens in Japan. We think that this study is significant because HP in thrombus specimens obtained from coronary artery in Japan seems to be of lower frequency than that of Europe. Although we suspect that the difference was caused by types of catheter, protocol, and procedure time of percutaneous interventions, we could not investigate correlation of HP in thrombus specimens with these factors. For future investigation, we should accumulate thrombus specimens obtained by routine procedure and device to clarify specific device-associated risk of disruption of HP.