title: Vascular elastography: a novel method to characterize occluded lower limb arteries prior to endovascular therapy.
abstract: OBJECTIVE
  To examine the effectiveness of vascular elastography (VE) for the assessment of totally occluded lower limb arteries prior to endovascular treatment (EVT).
  
  
  METHODS
  Of 812 consecutive patients who underwent EVT between April 2010 and April 2012, VE was used to evaluate the hardness of chronic total occlusions of the femoropopliteal segment prior to EVT in 65 consecutive patients (48 men; mean 73.9 years, range 63-86). Elastograms of the CTOs proximally and distally were scored using a 5-point scale, and outcomes in limbs with hard lesions (VE score 0-2) were compared to those with soft lesions (VE score 3-4) according to lesion length. The interventionists who performed the endovascular procedures were not informed of the VE score results.
  
  
  RESULTS
  CTO characteristics could be evaluated in all cases. A VE score ≤2 was found in 14 of the 23 lesions <150 mm in length. A flexible guidewire was sufficient for recanalization in more of the soft lesions than in the hard lesions [6/9 vs. 2/14, respectively]. In 39 lesions >150 mm, a VE score of 3 was recorded in most lesions proximally, while lesions distally were hard in many cases (VE score 1 or 2). A flexible guidewire alone was sufficient in many soft CTOs (8/13, p<0.01). In 16 cases, hard calcified plaque was indicated by difficulty in penetrating the lesion even with a stiff guidewire; all these cases had a VE score of 1 or 2. A retrograde approach was required only in hard CTOs (p<0.01). The procedure time was significantly longer for the hard lesion group (152.9±63.2 vs. 87.0±29.8 minutes, p=0.001). In 11 in-stent occlusions, only VE scores of 3 (n=4) or 4 (n=7) were recorded, indicating soft thrombus, which was aspirated under distal protection in 7 cases.
  
  
  CONCLUSIONS
  VE may be a useful method for determining the hardness of CTO lesions noninvasively before endovascular therapy, providing information that can help plan the procedure.
authors.affiliation: Department of Cardiology, Saiseikai Yokohama City Eastern Hospital, Yokohama, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Takimura
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hirano
authors.forename: Toshiya
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Reiko
authors.initials: R
authors.lastname: Tsukahara
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ito
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sakai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishimori
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Nakano
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamawaki
authors.forename: Motoharu
authors.initials: M
authors.lastname: Araki
authors.forename: Tamon
authors.initials: T
authors.lastname: Kato
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Ai
authors.initials: A
authors.lastname: Ishii
authors.forename: Takuro
authors.initials: T
authors.lastname: Takama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tokuda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation; D002908:Chronic Disease; D003251:Constriction, Pathologic; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004867:Equipment Design; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007564:Japan; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D058226:Plaque, Atherosclerotic; D011150:Popliteal Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D062666:Vascular Access Devices; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D059289:Vascular Stiffness
keywords: balloon angioplasty; chronic total occlusion; endovascular therapy; femoropopliteal segment; peripheral artery disease; popliteal artery; superficial femoral artery; ultrasonography