Abstract
AIM: To investigate the value of intraoperative angiography and its ad hoc evaluation with respect to cases of surgical technical inaccessibility. METHODS: Overall, 523 consecutive carotid artery thrombendarterectomy (TEA) patients with intraoperative control angiography, postoperative color-coded duplex sonography and retrospective re-evaluation of documented angiographic images were included in the evaluation. RESULTS: In the retrospective angiographic re-evaluation 23 (4.4%) occlusions or high-grade stenoses of the common carotid artery (CCA) or internal carotid artery (ICA) in the surgical field (12, 2.3%) or of downstream ICA or middle cerebral artery (MCA, 11, 2.1%) were detected. The detection rate was significantly lower in the intraoperative ad hoc evaluation with overall only 13 (2.5%) detected pathologies (7, 1.3% in the surgical field, 6, 1.1% in large downstream arteries, p=0.002). Postoperative duplex sonography performed in 505 patients detected 50 cases (10.1%) of local surgical technical inaccessibility, which was significantly more than in the angiography (p<0.001). In most cases these were nonocclusive, low-grade stenosing detachments of the intima media (n=19), 13 suture contractions, and 14 kinking/abrupt diameter changes at the distal end of the patch. Suture contractions and kinking/diameter changes were associated with a left-sided TEA (adjusted odds ratio, OR 2.4, 95% confidence interval, CI 1.1-5.1), an operation without a patch (adjusted OR, 16.6, 95% CI 1.3-215.0), and using Dacron patches in contrast to PTFE patches (adjusted OR 3.0, 95% CI 1.4-6.6). CONCLUSION: The ad hoc evaluation of intraoperative completion angiography by surgeons missed a substantial number also of occluding and severely stenosing pathologies. Angiography is not suitable for the detection of nonocclusive and low-grade stenosing cases of operative inaccessibility. Postoperative color-coded duplex sonography is an adequate tool for surgical quality control.