title: The S curve: a novel morphological finding in the internal carotid artery in patients with fibromuscular dysplasia.
abstract: Fibromuscular dysplasia (FMD) is a non-atherosclerotic vascular disease commonly affecting the renal and internal carotid arteries (ICAs). A previously unrecognized finding is a redundancy of the mid-distal ICA in FMD patients causing an 'S'-shaped curve. Carotid artery duplex ultrasounds were reviewed in 116 FMD patients to determine S-curve prevalence. FMD patients with an S curve were matched to four control patients divided equally into two groups: (1) age and sex-matched and (2) age ≥70 and sex-matched. S curves were present in 37 (32%) FMD patients. Of these, nine (24%) had angiographic evidence of FMD in their ICA only, 13 (35%) had renal artery FMD only, and 15 (41%) had both ICA and renal FMD. Two patients in the age and sex-matched group had S curves (odds ratio 16.86, 95% CI 3.92-72.48; p<0.0001) while 12 (16.2%) patients in the age ≥70 and sex-matched group had S curves (odds ratio 2.42, 95% CI 1.16-5.03; p=0.016). In conclusion, the S curve is a novel morphological pattern of the mid-distal ICA. While the S curve may not be specific, its presence in individuals <70 years old should alert the clinician to the possibility that FMD is present.
authors.affiliation: Zena and Michael A Wiener Cardiovascular Institute & the Marie-Josée and Henry R Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Sanjum S
authors.initials: SS
authors.lastname: Sethi
authors.affiliation: Zena and Michael A Wiener Cardiovascular Institute & the Marie-Josée and Henry R Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Joe F
authors.initials: JF
authors.lastname: Lau
authors.affiliation: Zena and Michael A Wiener Cardiovascular Institute & the Marie-Josée and Henry R Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: James
authors.initials: J
authors.lastname: Godbold
authors.affiliation: Zena and Michael A Wiener Cardiovascular Institute & the Marie-Josée and Henry R Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Gustavson
authors.affiliation: Zena and Michael A Wiener Cardiovascular Institute & the Marie-Josée and Henry R Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA jeffrey.olin@mountsinai.org.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Olin
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000473:pathology; D016022:Case-Control Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005352:Fibromuscular Dysplasia / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012016:Reference Values; D018570:Risk Assessment; D017678:Sex Distribution; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods
keywords: Doppler ultrasound; S curve; carotid artery; dissection; fibromuscular dysplasia; tortuosity