Resolution of lipid-containing atherosclerotic lesions induced by injury

Analysis of regression of postoperative carotid stenosis from prospective randomized trial of carotid endarterectomy comparing primary closure versus patching

BACKGROUND AND PURPOSE

Recurrent stenosis after carotid endarterectomy (CEA) has been reported to vary between a few percent and 30%. Regression of recurrent stenosis has been reported sporadically in the literature, but studies analyzing the factors affecting regression are lacking. This study analyzed factors affecting the regression of postoperative stenosis from a prospective randomized trial of CEA comparing primary closure (PC) versus patching.

PATIENT POPULATION AND METHODS

Three hundred ninety-nine CEAs were randomized into three groups: 135 PCs, 135 polytetrafluoroethylene patch closures (PTFE), and 130 vein patch closures (VPC). Postoperative duplex ultrasounds were done at 1, 6, and 12 months, and then yearly. The subgroup of these CEAs that exhibited postoperative stenosis was followed for possible regression of the stenosis. Analyses of various risk factors were examined for possible association with regression of recurrent stenosis. Mean follow-up was 46 months.

RESULTS

Of 105 postoperative stenoses, regression was noted in 6/64 (9%) in PC, 6/13 (46%) in PTFE, and 10/28 (36%) in VPC. Overall, 22 recurrent stenoses regressed; 19 regressed to normal and 3 regressed from 50% to 80% stenosis to 20% to <50% stenosis. The mean time to regression was 383 days. Regression was more common in patching than PC. Both VPC and PTFE had significantly more regression than PC. When stenoses of 50% to 80% were analyzed, patching had more regression than PC. None of the recurrent stenoses > or = 80% regressed. There was no association between regression and other factors, including gender, hypertension, diabetes mellitus, coronary artery disease, smoking, internal carotid artery diameter, hyperlipidemia, hypercholesterolemia, or aspirin intake.

CONCLUSIONS

Regression of recurrent stenosis was associated more strongly with patching than with PC. There was no association between regression and other factors.

Recurrent carotid artery stenosis following endarterectomy

Spectral analysis was used to examine 257 carotid arteries in 227 patients who had undergone carotid endarterectomy at 1, 3, 6, and 12 months after surgery and annually thereafter. Routine intraoperative completion angiography ensured that the operations were technically satisfactory. Postoperative restenoses were identified in 38 patients (15%). In 23 arteries (9%), the restenosis exceeded a 50% diameter reduction while in 15 arteries (6%) the stenosis was less than 50% of the diameter. Restenosis developed in 24/96 women (25%) and 14/161 men (9%). Twenty-nine (70%) stenotic lesions occurred within 12 months. In three patients early lesions regressed. Reoperation with patch angio-plasty was required in six patients. When the 219 carotid arteries that remained widely patent were compared to the 38 that restenosed , no differences were noted for age, diabetes mellitus, hypertension, smoking, or degree of preoperative stenosis. Early stenotic lesions appear to be due to myointimal hyperplasia, which is probably platelet mediated. The predominant female sex distribution may be explained by differences in platelet responsiveness in men and women.