Spontaneous regression of restenosis after CEA: significance of preoperative plaque characteristics under duplex ultrasound; clinical investigation.

Abstract

Restenosis is a postoperative complication after carotid endarterectomy (CEA). The natural clinical course of restenotic lesions is not yet fully understood. This study was aimed at detecting the pattern of restenotic lesions by way of following the plaque thickness under duplex ultrasound, and the possible relationship between the postoperative changes of restenotic lesions and the preoperative plaque characteristics. Serial duplex ultrasound follow-up studies were conducted postoperatively, and intima-media thickness (IMT) was measured to detect restenosis changes. Among 381 cases of CEA, including 25 cases of restenosis, 11 were eligible for further analysis. Of the 11 cases of restenosis, four showed a gradual increase in IMT, and five showed a temporary increase followed by a decrease in IMT. All cases in the former group showed isoechogenic or hypoechogenic plaques under preoperative duplex ultrasound. In contrast, all cases in the latter group demonstrated calcified plaques together with acoustic shadows. These postoperative chronological IMT data demonstrate two changing patterns of restenosis, implying the existence of two distinct entities. In addition, these results suggest that restenosis after removal of a calcified plaque, which supposedly forms secondary to myointimal hyperplasia, may be a temporary phenomenon that acutely develops in response to a dissection maneuver during surgery. Because our speculation is based on a small number of cases, further study is warranted to better understand the pathophysiology of restenosis regression.