Recognizing subtle near-occlusion in carotid stenosis patients: a computed tomography angiographic study

Koskinen, Suvi; Silvennoinen, Heli; Ijäs, Petra; Nuotio, Krista; Valanne, Leena; Lindsberg, Perttu J.; Soinne, Lauri

doi:10.1007/s00234-017-1791-5

Cited by 9 publications

(11 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In prognostic and management studies, separation of nearocclusion and conventional ≥ 50% carotid stenoses is made by assessing several features of near-occlusion [3][4][5]. Koskinen et al recently suggested that a ≥ 1.0-mm side-to-side difference in ICA diameter could be used to separate near-occlusion and conventional ≥ 50% stenosis [6]. However, asymmetry in the ICA caused by Circle of Willis (CoW) variation can also be associated with a 1.0-mm side-to-side difference of extracranial ICA diameter and mimic near-occlusion when coinciding with stenosis ( Fig.…”

Section: Introductionmentioning

confidence: 99%

Atherosclerotic ICA stenosis coinciding with ICA asymmetry associated with Circle of Willis variations can mimic near-occlusion

2019

View full text Add to dashboard Cite

Differentiating carotid near-occlusion (tight atherosclerotic stenosis causing distal artery size reduction) from conventional stenosis is the first step when grading carotid stenoses with NASCET method. The internal carotid artery (ICA) can be asymmetrically associated with Circle of Willis variations. When such ICA asymmetry coincides with stenosis, it may mimic nearocclusion. We studied ICA anatomical variant prevalence in 4042 consecutive CTA exams from all indications, 53 excluded due to carotid occlusion, 814 with any ≥ 50% steno-occlusive disease intra-or extracranially, 3228 without. Of the 3989 included cases, 568 (14%) had ICA asymmetry, of which 335 (59%) were from associated with Circle of Willis variations. Of 3228 patients without ≥ 50% stenosis or other steno-occlusive disease intra-and extracranially; 257 (8.0%) demonstrated ICA asymmetry associated with Circle of Willis variations, equally common among sexes and age unrelated and most frequently attributed to an ipsilateral A1 hypoplasia/aplasia, less often attributed to large contralateral posterior communicating artery. As ICA asymmetry associated with Circle of Willis variations are common, caution should be exercised diagnosing near-occlusion on asymmetry alone.

show abstract

Section: Introductionmentioning

confidence: 99%

Atherosclerotic ICA stenosis coinciding with ICA asymmetry associated with Circle of Willis variations can mimic near-occlusion

2019

View full text Add to dashboard Cite

show abstract

“…Today, the measurement and decision making mostly rely on CTA and/or magnetic resonance angiography imaging. 32,33 Other imaging features, such as plaque area on computerised plaque analyses, 34 intraplaque haemorrhage Figure 5. The development of stroke prevention potential at Helsinki University Hospital (HUH).…”

Section: Grade Of Stenosis and Plaque Characteristicsmentioning

confidence: 99%

The Efficacy of Carotid Surgery by Subgroups: The Concept of Stroke Prevention Potential

Aro

Ijäs

Vikatmaa

et al. 2019

European Journal of Vascular and Endovascular Surgery

Self Cite

View full text Add to dashboard Cite

WHAT THIS PAPER ADDS Patient selection should be a key component of carotid surgery reports. A calculator was created where the presence and recentness of symptoms, sex, increasing stenosis severity, and complication rates could all be combined into a single figure. The calculator was tested on real life material and some theoretical inclusion scenarios. Single hospital treatment development over time and benchmarking between hospitals can be monitored when registered data includes these parameters, ultimately leading to improved patient selection.Objective: Considering carotid endarterectomy (CEA), reporting treatment delay, symptom status, and surgical complication rates separately gives an incomplete picture of efficacy; therefore, the aim was to combine these factors and develop a reporting standard that better describes the number of potentially prevented strokes. With a real life cohort and theoretical inclusion scenarios, the aim was to explore the stroke prevention potential of different carotid practices. Methods: Landmark studies for symptomatic and asymptomatic patients were revisited. By using published estimates of treatment effect, a simplified calculator was designed to assess the five year stroke prevention rate per 1000 CEAs (stroke prevention potential [SPP], range 0e478), including the presence and recentness of symptoms, sex, increasing stenosis severity, and complication rates. Patients operated on for carotid stenosis at Helsinki University Hospital (HUH) between 2008 and 2016 were collected from a vascular registry (HUSVASC) and categorised according to the model. The local annual complication rate was re-evaluated and added to the model. The HUH patient cohort was incorporated into the SPP model, and changes over time analysed. Finally, theoretical changes in patient selection were compared in order to explore the theoretical impact of patient selection and shortening of the delay. Results: Fifteen hundred and five symptomatic and 356 asymptomatic carotid stenoses were operated on with stroke plus death rates of 3.6% and 0.3%, respectively. The proportion of CEAs performed within two weeks of the index event increased over the follow up period, being 77% in 2016. The SPP increased from 123 in 2008 to 229 in 2016. Theoretically, 350 ischaemic strokes were prevented in the period 2008e16, with 1861 CEAs. Conclusions: National and international comparison of different CEA series is irrelevant if the inclusion criteria are not considered. A calculator that is easy to apply to large scale high quality registered data was developed and tested. SPP was found to increase over time, which is a probable sign of improved patient selection and an increased number of strokes prevented by the CEAs performed.

show abstract

“…It is also important to interpret what is seen, such as whether side-to-side asymmetry is likely due to uniform collapse or something else such as old dissections or anatomical variance. An example of the interpretive approach using the illustrated case in the new article [1] is that there is a clearly visible side-to-side difference with uniform collapse where the distal artery otherwise seems normal (A + C), small absolute ICA size (B and provided measurement), ICA similar to ECA (A + C), and stenosis hard to assess due to calcifications. The interpretation of these findings is a nearocclusion without full collapse, and the interpretation seems certain from available information (even though the stenosis could not be clearly assessed, but it could be impressive).…”

Section: Interpretative Approach To Near-occlusion Diagnosismentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

Diagnosing carotid near-occlusion with 1 mm side-to-side asymmetry: a tough task made too easy

Johansson

Fox

2017

Neuroradiology

View full text Add to dashboard Cite

In this issue of Neuroradiology, Koskinen and colleagues present their idea: that carotid near-occlusion (a tight stenosis that causes a collapse of the distal artery) can be separated from conventional ≥50% stenosis by measuring the distal diameter and all cases with ≥1.0 mm side-to-side difference is a nearocclusion [1]. Their goal was Bto facilitate the recognition and diagnosis of near-occlusion, and raise the notion that even when a subtle distal ICA LD [Luminal Diameter] reduction is present, a possible near-occlusion should be considered.^It is important to raise awareness of near-occlusions without full collapse, when the distal artery otherwise seems normal, albeit smaller than usual. Indeed, this issue is so important that we recently ranked it as one of the two major near-occlusion issues in most need of improvement [2]. Any neuroradiologist who is not well aware of the near-occlusion without full collapse would do well to apply this as a first step towards improved understanding. However, apart from raising initial awareness, we advocate against the use of this proposed 1.0 mm criterion for diagnosing near-occlusion. Interpretative approach to near-occlusion diagnosisCarotid near-occlusion is a pattern-recognition diagnosis where interpretation of multiple key features is at the core of diagnosis [3]. These multiple key features have been presented before [4,5]: for both conventional angiography and CTA, side-to-side ICA difference and similar-sized or smaller ICA than ECA are features; for conventional angiography, delay of contrast and evidence of collaterals are features; and for CTA, absolute ICA size and impressive stenosis are features. BImpressive^stenosis applies to when contrast is hardly (or no longer) seen in the stenosis [4] and remaining features are Bpositive^when visible to the eye of the observer. Studies with sensitivity and specificity of these features have compared to interpretation [4,5]. Hence, a previously reported 0.87 side-to-side ratio was an approximation of what was visible [4]. It is also important to interpret what is seen, such as whether side-to-side asymmetry is likely due to uniform collapse or something else such as old dissections or anatomical variance. An example of the interpretive approach using the illustrated case in the new article [1] is that there is a clearly visible side-to-side difference with uniform collapse where the distal artery otherwise seems normal (A + C), small absolute ICA size (B and provided measurement), ICA similar to ECA (A + C), and stenosis hard to assess due to calcifications. The interpretation of these findings is a nearocclusion without full collapse, and the interpretation seems certain from available information (even though the stenosis could not be clearly assessed, but it could be impressive). The interpretative approach is justified as it was used for the pooled NASCET and ECST analyses [5], from which we base our understanding of prognosis and management. While the definition of near-occlusion with interpretation might still...

show abstract

Recognizing subtle near-occlusion in carotid stenosis patients: a computed tomography angiographic study

Cited by 9 publications

References 14 publications

Atherosclerotic ICA stenosis coinciding with ICA asymmetry associated with Circle of Willis variations can mimic near-occlusion

Atherosclerotic ICA stenosis coinciding with ICA asymmetry associated with Circle of Willis variations can mimic near-occlusion

The Efficacy of Carotid Surgery by Subgroups: The Concept of Stroke Prevention Potential

Diagnosing carotid near-occlusion with 1 mm side-to-side asymmetry: a tough task made too easy

Contact Info

Product

Resources

About