Ultrasonografic monitoring of hemodynamic parameters in symptomatic and asymptomatic patients with high-grade carotid stenosis prior and following carotid endarterectomy

Abstract

Background/Aim. Doppler ultrasonography is now a reliable diagnostic tool for noninvasive examination of the morphology and hemodynamic parameters of extracranial segments of blood vessels that participate in the brain vascularisation. This diagnostic modality in recent years become the only diagnostic tool prior to surgery. The aim of the study was to determine hemodynamic status in symptomatic and asymtomatic patients with severe carotid stenosis prior to and after carotid endarterectomy (CEA). Methods. A total of 124 symptomatic and 94 asymptomatic patients who had underwent CEA at the Clinic for Cardiovasculare Disease ?Dedinje? in Belgrade were included in this study. Doppler ultrasonography examinations were performed one day before CEA and seven days after it. The peak systolic velocity (PSV), end-dyastolic velocity (EDV), time-averaged maximum blood flow velocity (MV), resistance index (RI) and the blood flow volume (BFV) of the ipsilateral and the contralateral internal carotid artery (ICA) were measured. Results. Diabetes was the only risk factor found significantly more frequent in symptomatic patients. There were significantly more occluded contralateral ICAs in the group of symptomatic patients. There was a significant increase in PSV, EDV, MV and BFV of the ipsilateral ICA after CEA and a significant decrease in PSV, EDV, MV and BFV of the contralateral ICA after CEA. RI is the only hemodynamic parameter without significant changes after CEA in both groups of patients. Comparing the values of hemodynamic parameters after CEA between the group of symptomatic and the group of asymptomatic patients no significant differences were found. Conclusion. The occlusion of the contralateral ICA is an important factor differentiating between symptomatic and asymptomatic patients with severe carotid stenosis. Successful surgery provides good recovery of cerebral hemodynamics in both symtomatic and asymptomatic patients.Uvod/Cilj. Dopler ultrasonografija danas je pouzdano dijagnosticko sredstvo za neinvazivno ispitivanje morfologije i hemodinamskih parametara ekstrakranijalnih segmenata krvnih sudova koji ucestvuju u vaskularizaciji mozga. Ovaj dijagnosticki modalitet u poslednje vreme postaje jedino dijagnosticko sredstvo koje prethodi hirurskoj intervenciji. Cilj rada bio je da se prikaze hemodinamski status pre i posle karotidne endarterektomije (CEA) kod simptomatskih i asimtomatskih bolesnika sa visokostepenom karotidnom stenozom. Metode. U ispitivanje su bila ukljucena 124 simptomatska i 94 asimtomatska bolesnika kojima je ucinjena karotidna endarterektomija u Klinici za vaskularnu hirurgiju Instituta za kardiovaskularne bolesti ?Dedinje? u Beogradu. Kod svakog bolesnika ucinjeno je dopler ultrasonografsko ispitivanje neposredno pre operacije, kao i sedam dana nakon operacije. Mereni su maksimalna sistolna brzina (peak systolic velocity - PSV), brzina na kraju dijastole (end dyastolic velocity - EDV), srednjevremenska maksimalna brzina protoka (mean velocity - MV), indeks otpora (resistance index - RI) i volumen protoka (blood flow volume - BFV) operisane (ipsilateralne) i kontralateralne unutrasnje karotidne arterije (internal carotid artery - ICA). Rezultati. Dijabetes je jedini faktor rizika koji je statisticki znacajno cesci u grupi simptomatskih bolesnika. Postoji statisticki znacajno veci broj bolesnika sa okludiranom kontralateralnom ICA u grupi simptomatskih bolesnika. Nakon operacije dolazi do statisticki znacajnog povecanja PSV, EDV, MV, kao i BFV operisane ICA. Nakon operacije ICA dolazi do statisticki znacajnog smanjenja PSV, EDV, MV, kao i BFV kontralateralne ICA. Jedini hemodinamski parametar koji se ne menja nakon operacije je RI kod obe grupe bolesnika. Uporedjivanjem promena ispitivanih hemodinamskih parametara ipsilateralne i kontralateralne ICA, koje su nastale nakon operacije, nisu nadjene znacajne razlike kod ispitivanih grupa bolesnika.. Zakljucak. Okluzija kontralaterealne ICA je faktor koji znacajno doprinosi pojavi simptoma visokostepene karotidne stenoze. Uspesna CEA obezbedjuje poboljsanje hemodinamike cerebralne cirkulacije kod simptomatskih i asimptomatskih bolesnika.