Abstract:

Introduction: pathological tortuosity of internal carotid arteries (ICA) is widespread; its frequency in population varies within 18-34%. Currently, there are several approaches for the determination of indications for surgical intervention in pathological ICA tortuosity. The main criteria are hemodynamic changes in the arterial flow and the presence of neurological symptoms, so an informative preoperative examination is an integral part in treatment strategy determination in patients' subsequent treatment.

Aim: was to estimate the condition of carotid arteries and substance of the brain in isolated pathological tortuosity and in combination with stenotic lesions, based on results of CT angiography.

Materials and methods: we analyzed results of examination and treatment of 70 patients. Ultrasound and CT angiography of brachiocephalic arteries were performed on a Philips iCT 256-slice multislice computed tomograph. During CT angiography, a non-contrast study, arterial and venous phases of contrast enhancement were performed with an intravenous bolus injection of 50.0 ml of isoosmolar iodinated contrast-agent at 4-5 ml/sec.

Patients were divided into two groups: patients with isolated pathological carotid tortuosity (28 pts) and patients with a combination of carotid tortuosity and stenotic lesions (42 pts). We assessed the effect of carotid tortuosity on the severity of the brain tissue alterations using statistical analysis.

Results: a lesser severity of changes in the substance of the brain was noted in patients in the group with isolated pathological tortuosity of ICA. In 9 cases, we did not detect focal lesions; in 15 cases, small foci of microangiopathy and individual cerebrospinal fluid cysts were noted, in 4 patients, we noted areas and zones of cystic-glial changes. S- and C-shaped deformation became the most frequent variants of tortuosity; the formation of 3 saccular aneurysms (two true and one false) was revealed.

Manifestations of ischemic damage of the brain substance in the group of patients with a combination of ICA tortuosity and stenotic lesion were more pronounced. Thus, in 11 cases, zones and areas of cystic-glial changes were determined within the framework of past cerebrovascular accidents; in 20 patients, foci of microangiopathy expressed in varying degrees, as well as individual cerebrospinal fluid cysts, were noted. In 11 cases, no focal lesions were detected in the brain.

Statistical processing showed a correlation between the condition of carotid arteries and the presence of focal brain damage - in the group with combination of pathological tortuosity and stenosis of ICA, more pronounced chronic ischemic brain damage was detected (p=0,012).

Conclusion: CT-angiography was noted to be highly informative in assessment of condition of carotid arteries and brain substance in patients with isolated pathological tortuosity, as well as in combination with a stenotic lesion of internal carotid arteries. With a combination of pathological tortuosity and a stenosis in internal carotid arteries, data were obtained on a more pronounced damage of the brain substance. According to computed tomography, clinical manifestations of chronic cerebrovascular insufficiency were generally more pronounced compared to changes in the brain substance. However, there was a correlation between the increase in the degree of chronic cerebrovascular insufficiency and the aggravation of the state of the brain substance.

Abstract:

Aim: was to assess computed tomography angiography (CTA) abilities in analysis of internal carotid artery (ICA) critical atherosclerotic lesions.

Material and method: for the period 2014-2016 - 321 patients underwent examination (ultrasound and CTA of brachiocephalic arteries) prior to surgical treatment of ICA occlusive disease. CTA was made on Philips iCT 256-slice (noncontrast examination, arterial and venous phases), 50 ml on nonionic contrast agent was injected (4-4,5 ml/sec). We distinguished several types of ICA changes: stenosis more than 60% and 70%, critical stenosis, subocclusion (also with distal collapse), local occlusion.

Results: CTitical ICA stenosis was detected in 82 patients (26% of all observed cases); ICA changes with diffuse decrease of upper segments - in 20 cases (6,2% of cases). Among group of decreased diameter we saw subocclusion (18 patients) and local occlusion (2 patients). In the setting of local occlusion ICA contrast-enchanced through atypical ascending pharyngeal artery In patients with diffuse decrease of upper ICA segments all elements of circle of Wills were detected in 70% of cases. During surgery CTA results were confirmed, but atherosclerotic plaque extension was higher than observed at CT approximately at 10 mm.

Conclusion: we can refer critical stenosis, subocclusion and local occlusion to critical atherosclerotic ICA changes. The one should consider CTA limitations in differentiation of upper part of atherosclerotic plaque. In majority of cases decrease in ICA diameter was associated with severe atherosclerotic involvement and not with congenital changes CTA is necessary for preoperative assessment of carotid occlusive disease, especially in critical ICA changes.

References

1.     John J. Ricotta, Ali AbuRahma, Enrico Ascher, Mark Eskandari, Peter Faries and Brajesh K. Lal. Washington, DC; Charleston, WV; Brooklyn, NY; Chicago, Ill; New York, NY; and Baltimore, Md Updated Society for Vascular Surgery guidelines for management of extracranial carotid disease. J Vasc Surg. 2011: Sep; 54(3):1-31.

2.     Nacional'nye rekomendacii po vedeniyu pacientov s zabolevaniyami brahiocefal'nyh arterij [National recommendations on treatment of brachicephalic arteries disease]. Rossijskij soglasitel'nyj dokument. 2013; 72S [ In Russ].

а)  Nacional'nye rekomendacii po vedeniyu pacientov s zabolevaniyami brahiocefal'nyh arterij [National recommendations on treatment of brachicephalic arteries disease] [Elektronnyj resurs]: ros. soglasit. dok. /Ros. o-vo angiologov i sosudistyh hirurgov, Assoc. serdech.-sosudistyh hirurgov Rossii, Ros. nauch. o-vo rentgenehndovaskulyar. hirurgov i intervencion. radiologov, Vseros. nauch. o-vo kardiologov, Assoc. flebologov Rossii ; L. A. Bokeriya, A. V. Pokrovskij, G. YU. Sokurenko [i dr.]. - M., 2013. - 72 s. - Rezhim dostupa: www. url: http://www.angiolsurgery.org /recommendations2013/recommendations_brachio- cephalic.pdf . 03.04.2015 [In Russ].

b)  Nacional'nye rekomendacii po vedeniju pacientov s zabolevanijami brahiocefal'nyh arteriT [National recommendations on treatment of brachicephalic arteries disease]. M.2013 [In Russ].

3.     Johansson E. and A.J. Fox., Carotid Near-Occlusion: A Comprehensive Review, Part 2-Prognosis and Treatment, Pathophysiology, Confusions, and Areas for Improvement. American Journal of Neuroradiology 2016; 37(2):200-204.

4.     Johansson E. and A.J. Fox., Carotid Near-Occlusion: A Comprehensive Review, Part 1- Definition, Terminology, and Diagnosis. American Journal of Neuroradiology Jan 2016; 37(1):2-10.

5.     Vishnyakova M.V., Pronin I.N., Lar'kov R.N., Zagarov S.S. Komp'yuterno-tomograficheskaya angiografiya v planirovanii rekonstruktivnyh operacij na vnutrennih sonnyh arteriyah [CT-angiography in planning of reconstructive operations on internal carotid arteries]. Diagnosticheskaya i intervencionnaya radiologiya. 2016; 10(3):11-19 [In Russ].

6.     Suzie M. El-Saden, Edward G. Grant, Gasser M. Hathout, Peter T. Zimmerman, Stanley N. Cohen, and J. Dennis Baker. Imaging of the internal carotid artery: the dilemma of total versus near total occlusion. Radiology 2001; 221(2):301-308.

7.     Mamedov F.R., Arutyunov N.V., Usachev D. YU, Lukshin V.A., Mel'nikova-Pickhelauri T.V., Fadeeva L.M., Pronin I.N., Kornienko V.N. Sovremennye metody nejrovizualizacii pri stenoziruyushchej i okklyuziruyushchej patologii sonnyh arterij [Modern methods of neurovisualization in stenotic and occlusive pathology of carotid arteries.]. Luchevaya diag nostika i terapiya. 2012; 3(3):109-116 [In Russ].

8.     Vishnyakova M.V. (ml), Pronin I.N., Lar'kov R.N., Vishnyakova M.V.. Detalizaciya okklyuziruyushchego porazheniya vnutrennej sonnoj arterii pri komp'yuternoj tomograficheskoj angiografii dlya planirovaniya rekonstruktivnyh operacij [Detalization of occlusive lesion of internal carotid artery in CT angiography for planning of reconstrutive operations]. Vestnik rentgenologii i radiologii. 2017; 98(2):69-77 [In Russ].

9.     Lippman H.H., Sundt T.M. Jr., Holman C.B.. The poststenotic carotid slim sign: spurious internal carotid hypolasia. Mayo Clin Proc. 1970; 45:762-767.

10.   Fox Allan J., Michael Eliasziw, Peter M. Rothwell, Matthias H. Schmidt, Charles P. Warlow, Henry J.M. Barnett. Identification, Prognosis, and Management of Patients with Carotid Artery Near Occlusion. American Journal of Neuroradiology. Sep 2005; 26(8):2086-2094

11.   Johansson E., Chman K., Wester P.. Symptomatic carotid near-occlusion with full collapse might cause a very high risk of stroke. J Intern Med 2015; 277:615-623.