umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Carotid stenosis
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
2011 (English)Doctoral thesis, comprehensive summary (Other academic)Alternative title
Karotisstenos (Swedish)
Abstract [en]

Carotid stenosis is one of several causes of ischemic stroke and entails a high risk of ischemic stroke recurrence. Removal of a carotid stenosis by carotid endarterectomy results in a risk reduction for ischemic stroke, but the magnitude of risk reduction depends on several factors. If the delay between the last symptom and carotid endarterectomy is less than 2 weeks, the absolute risk reduction is >10%, regardless of age, sex, or if the degree of carotid stenosis is 50–69% or 70–99%. Thus, speed is the key. However, if many patients suffers an ischemic stroke recurrence within the first 2 weeks of the presenting event, an additional benefit is likely be obtained if carotid endarterectomy is performed even earlier than within 2 week after the presenting event.

Carotid endarterectomy for asymptomatic carotid stenoses carries a small risk reduction for stroke. Screening for asymptomatic carotid stenosis requires a prevalence of >5% in the examined population, i.e., higher than in the general population; however, directed screening in groups with a prevalence of >5% is beneficial.

The aims of this thesis were to investigate the length of the delay to carotid endarterectomy, determine the risk of recurrent stroke before carotid endarterectomy, and determine if a calcification in the area of the carotid arteries seen on dental panoramic radiographs is a valid selection method for directed ultrasound screening to detect asymptomatic carotid stenosis.

Consecutive patients with a symptomatic carotid stenosis who underwent a preoperative evaluation aimed at carotid endarterectomy at Umeå Stroke Centre between January 1, 2004–March 31, 2006 (n=275) were collected retrospectively and between August 1, 2007–December 31, 2009 (n=230) prospectively. In addition, 117 consecutive persons, all preliminarily eligible for asymptomatic carotid endarterectomy and with a calcification in the area of the carotid arteries seen on panoramic radiographs, were prospectively examined with carotid ultrasound.

The median delay between the presenting event and carotid endarterectomy was 11.7 weeks in the first half year of 2004, dropped to 6.9 weeks in the first quarter year of 2006, and had dropped to 3.6 weeks in the second half year of 2009.

The risk of ipsilateral ischemic stroke recurrence was 4.8% within 2 days, 7.9% within 1 week, and 11.2% within 2 weeks of the presenting event. For patients with a stroke or transient ischemic attack as the presenting event, this risk was 6.0% within 2 days, 9.7% within 1 week, and 14.3% within 2 weeks of the presenting event. For the 10 patients with a near-occlusion, the risk of ipsilateral ischemic stroke recurrence was 50% at 4 weeks after the presenting event.

Among the 117 persons with a calcification in the area of the carotid arteries seen on panoramic radiographs, eight had a 50–99% carotid stenosis, equalling a prevalence of 6.8% (not statistically significantly over the pre-specified 5% threshold). Among men, the prevalence of 50–99% carotid stenosis was 12.5%, which was statistically significantly over the pre-specified 5% threshold.

In conclusion: The delay to carotid endarterectomy was longer than 2 weeks. Additional benefit is likely to be gained by performing carotid endarterectomy within a few days of the presenting event instead of at 2 weeks because many patients suffer a stroke recurrence within a few days; speed is indeed the key. The finding that near-occlusion entails an early high risk of stroke recurrence stands in sharp contrast to previous studies; one possible explaination is that this was a high-risk period missed in previous studies. The incidental finding of a calcification in the area of the carotid arteries on a panoramic radiograph is a valid indication for carotid ultrasound screening in men who are otherwise eligible for asymptomatic carotid endarterectomy.

Place, publisher, year, edition, pages
Umeå: Umeå universitet , 2011. , 101 p.
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1446
Keyword [en]
Carotid stenosis, Risk, Recurrence, Stroke, TIA, Near-occlusion, Carotid Endarterectomy, Delay, Panoramic Radiographs
National Category
Other Clinical Medicine Neurology
Research subject
Internal Medicine; Neurology; Odontology
Identifiers
URN: urn:nbn:se:umu:diva-46396ISBN: 978-91-7459-289-4 (print)OAI: oai:DiVA.org:umu-46396DiVA: diva2:440066
Public defence
2011-10-27, Bergasalen, Norrlands Universitetssjukhus, Umeå, 13:00 (Swedish)
Opponent
Supervisors
Available from: 2011-10-06 Created: 2011-08-31 Last updated: 2015-06-11Bibliographically approved
List of papers
1. Delay from symptoms to carotid endarterectomy
Open this publication in new window or tab >>Delay from symptoms to carotid endarterectomy
2008 (English)In: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 263, no 4, 404-411 p.Article in journal (Refereed) Published
Abstract [en]

Objectives.  To investigate the time between cerebrovascular symptom and carotid endarterectomy (CEA), what prolongs this time and if and when the patients suffer additional cerebrovascular events.

Design.  Observational.

Setting.  Single Centre study at a specialized Stroke Centre.

Subjects.  A total of 275 patients with ≥50% symptomatic carotid stenosis (according to the NASCET-criteria) between 1 January 2004 and 31 March 2006.

Main outcome measures.  Time between cerebrovascular symptom and CEA, time between different parts of the investigation, additional cerebrovascular symptoms before CEA and as perioperative complication.

Results.  A total of 128 patients underwent CEA. The median time between symptom and CEA was 11.7 weeks in the beginning and 6.9 weeks at the end of the study. Seven per cent were operated within 2 weeks and 11% between 2 and 4 weeks after their cerebrovascular symptom. The time delays were most pronounced between symptom onset and arrival at the Umeå Stroke Centre from the secondary hospitals and between the decision to recommend CEA and the CEA. Twenty-eight per cent of the patients who were intended for surgery suffered additional cerebrovascular events, 1.4% suffered a major stroke which excluded the indication of CEA and 3.0% of the CEA patients suffered a stroke with functional dependence within 30 days of the operation.

Conclusions.  The delay between symptom and CEA was substantially longer than the desired 2 weeks. Many patients suffered additional cerebrovascular events before CEA. The risk of a severe additional stroke before CEA was about the same as the risk of a severe complication from the CEA.

Keyword
Adult, Aged, Aged; 80 and over, Carotid Artery; Internal/*surgery, Carotid Stenosis/complications/*surgery, Endarterectomy; Carotid/*adverse effects/statistics & numerical data, Female, Humans, Intraoperative Complications/*prevention & control, Male, Middle Aged, Risk Factors, Stroke/prevention & control, Time Factors
National Category
Family Medicine
Identifiers
urn:nbn:se:umu:diva-9515 (URN)10.1111/j.1365-2796.2007.01908.x (DOI)18266661 (PubMedID)
Available from: 2008-04-14 Created: 2008-04-14 Last updated: 2015-06-11Bibliographically approved
2. Risk of recurrent stroke before carotid endarterectomy: the ANSYSCAP study
Open this publication in new window or tab >>Risk of recurrent stroke before carotid endarterectomy: the ANSYSCAP study
2013 (English)In: International Journal of Stroke, ISSN 1747-4930, E-ISSN 1747-4949, Vol. 8, no 4, 220-227 p.Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Carotid endarterectomy yields greater risk reduction for ipsilateral ischemic stroke when performed within two-weeks of the last cerebrovascular symptom than when performed two-weeks or more after the last symptom. However, additional benefit might be gained if carotid endarterectomy is performed earlier than within two-weeks. AIMS: To investigate the 90-day risk of ipsilateral ischemic stroke recurrence after amaurosis fugax, retinal artery occlusion, transient ischemic attack, or minor ischemic stroke in patients with 50-99% carotid stenosis before carotid endarterectomy, with emphasis on the first 14 days. METHODS: Prospective cohort study. 230 consecutive patients with symptomatic 50-99% carotid stenosis (North American Symptomatic Carotid Endarterectomy Trial grading method) who underwent evaluation before carotid endarterectomy. Of these, 183 underwent carotid endarterectomy; the median delay to carotid endarterectomy was 29 days. Blood pressure lowering medication was used by 93% and lipid-lowering medication by 90%. RESULTS: The risk of ipsilateral ischemic stroke recurrence before carotid endarterectomy was 5·2% (n = 12) within two-days, 7·9% (n = 18) within seven-days, 11·2% (n = 25) within 14 days, and 18·6% (n = 33) within 90 days of the presenting event. The risk of ipsilateral ischemic stroke recurrence was higher if the presenting event was a stroke (adjusted hazard ratio 12·4, P = 0·015) or transient ischemic attack (adjusted hazard ratio 10·2, P = 0·026) compared with an amaurosis fugax. DISCUSSION: The risk of recurrent ipsilateral ischemic stroke was high within the first days of the presenting event. Many recurrences would likely have been avoided if carotid endarterectomy had been performed within the first days of the presenting event.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2013
Keyword
Stroke, Carotid Stenosis, Risk, Recurrence
National Category
Neurology Cardiac and Cardiovascular Systems
Research subject
Neurology
Identifiers
urn:nbn:se:umu:diva-46712 (URN)10.1111/j.1747-4949.2012.00790.x (DOI)000319398900012 ()22494778 (PubMedID)
Note

Originally published in thesis in submitted form.

First published online: April 12, 2012.

Available from: 2011-09-12 Created: 2011-09-12 Last updated: 2017-12-08Bibliographically approved
3. Risk of recurrent ipsilateral ischemic stroke in patients with symptomatic near-occlusion
Open this publication in new window or tab >>Risk of recurrent ipsilateral ischemic stroke in patients with symptomatic near-occlusion
(English)Manuscript (preprint) (Other academic)
Keyword
Carotid stenosis. Near-occlusion. Risk. Recurrence. Stroke.
National Category
Neurology
Research subject
Internal Medicine; Neurology
Identifiers
urn:nbn:se:umu:diva-46714 (URN)
Available from: 2011-09-12 Created: 2011-09-12 Last updated: 2015-06-11Bibliographically approved
4. Ultrasound screening for asymptomatic carotid stenosis in subjects with calcifications in the area of the carotid arteries on panoramic radiographs: a cross-sectional study
Open this publication in new window or tab >>Ultrasound screening for asymptomatic carotid stenosis in subjects with calcifications in the area of the carotid arteries on panoramic radiographs: a cross-sectional study
Show others...
2011 (English)In: BMC Cardiovascular Disorders, ISSN 1471-2261, E-ISSN 1471-2261, Vol. 11, no 44, 1-9 p.Article in journal (Refereed) Published
Abstract [en]

Background: Directed ultrasonic screening for carotid stenosis is cost-effective in populations with > 5% prevalence of the diagnosis. Occasionally, calcifications in the area of the carotid arteries are incidentally detected on odontological panoramic radiographs. We aimed to determine if directed screening for carotid stenosis with ultrasound is indicated in individuals with such calcifications. Methods: This was a cross-sectional study. Carotid ultrasound examinations were performed on consecutive persons, with findings of calcifications in the area of the carotid arteries on panoramic radiography that were otherwise eligible for asymptomatic carotid endarterectomy. Results: Calcification in the area of the carotid arteries was seen in 176 of 1182 persons undergoing panoramic radiography. Of these, 117 fulfilled the inclusion criterion and were examined with carotid ultrasound. Eight persons (6.8%; 95% CI 2.2-11.5%) had a carotid stenosis - not significant over the 5% pre-specified threshold (p = 0.232, Binomial test). However, there was a significant sex difference (p = 0.008), as all stenoses were found in men. Among men, 12.5% (95% CI 4.2-20.8%) had carotid stenosis - significantly over the 5% pre-specified threshold (p = 0.014, Binomial test). Conclusions: The incidental finding of calcification in the area of the carotid arteries on panoramic radiographs should be followed up with carotid screening in men that are otherwise eligible for asymptomatic carotid endarterectomy.

Place, publisher, year, edition, pages
BioMed Central, 2011
Keyword
endarterectomy, stroke, emboli, trial, risk
National Category
Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:umu:diva-45670 (URN)10.1186/1471-2261-11-44 (DOI)000294287500001 ()21752238 (PubMedID)
Available from: 2011-08-09 Created: 2011-08-09 Last updated: 2017-12-08Bibliographically approved

Open Access in DiVA

fulltext(2064 kB)612 downloads
File information
File name FULLTEXT01.pdfFile size 2064 kBChecksum SHA-512
69cedf1329bdc607e020b219b46a958d8622bb97f7fb8ea277cbb6536f82fec49f4419a588251e603aac9c444a2b701881318b7b97c6c8ad9e5e2a2ce21bab98
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Johansson, Elias
By organisation
Department of Public Health and Clinical Medicine
Other Clinical MedicineNeurology

Search outside of DiVA

GoogleGoogle Scholar
Total: 612 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1456 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf