Residual lesions and early recurrent stenosis after carotid endarterectomy. A serial follow-up study with duplex scanning and intravenous digital subtraction angiography.

In 109 internal carotid endarterectomies a complete serial follow-up study with ultrasonic duplex scanning was performed at 3, 6, and 12 months after operation. A duplex scan was also performed 2 years postoperatively in 75 cases. Moreover, the state of the endarterectomized carotid bifurcations was documented by intravenous digital subtraction angiography during hospitalization and at 12 months. At 3, 6, 12, and 24 months after operation the rate of significant recurrent stenosis was 6%, 12%, 6%, and 8%, respectively. Approximately half of the arteries with a significant stenosis at 1 year already demonstrated this lesion with intravenous digital subtraction angiography performed 1 week after operation. Persistent significant recurrent stenosis in the remaining arteries was probably the result of excessive myointimal proliferation. This occurred with a higher frequency in women (14.8%) than in men (4.1%). The greater number of the arteries with minimally or mildly disturbed spectral waveforms 3 months after endarterectomy spontaneously normalized or remained stable during the follow-up period. On the other hand, 40% of the arteries with a significant stenosis (diameter reduction of 50% or more) at the three-month control follow-up period increased to a more severe degree of stenosis during the first postoperative year. Most of the operated arteries did not significantly change during the second year.