title: Gray-scale median of the atherosclerotic plaque can predict success of lumen re-entry during subintimal femoral-popliteal angioplasty.
abstract: OBJECTIVE
  This study assessed whether the duplex ultrasound (DUS)-derived gray-scale median (GSM) of the most six distal portion of the occluded femoral-popliteal arterial segment can predict success of lumen re-entry for subintimal angioplasty.
  
  
  METHODS
  During the last 3 years, 108 patients (62% men) with a mean age of 73 +/- 10 years underwent 116 primary attempted DUS-guided subintimal angioplasties of the femoral-popliteal segment. Preprocedural B-mode DUS images of the plaque at the most distal occlusion segment were digitalized and normalized using Photoshop (Adobe, San Jose, Calif) software and standard criteria (gray level, 0 to 5 for lumen blood and 185 to 190 for the adventitia on a linear scale of 0 to 255). Overall GSM of the plaque segment about 2 cm long, immediately before the planned re-entry point to the true arterial lumen, was used for retrospective correlation with procedure success and other clinical indicators.
  
  
  RESULTS
  Mean plaque GSM for all cases was 22.5 +/- 12.6 (range, 3 to 60). The overall success rate of subintimal angioplasty procedures was 85%. Mean plaque GSM for 99 successful cases (18.4 +/- 7.8) was significantly lower than for 17 cases (46.4 +/- 8.1) where we failed (P < .0001). We failed in 90% of 19 cases with GSM >35, in 71% of 24 cases with GSM >20, and in 50% of 34 cases with GSM >25. There was no statistically significant difference (P = .45) between plaque GSM in 64 patients with diabetes (23.3 +/- 13.5) compared with 52 nondiabetic patients (21.5 +/- 11.4). Similarly, plaque GSM was not statistically different (P = .9) in 52 patients with renal insufficiency (22.7 +/- 13.2) compared with 64 patients with normal creatinine levels (22.4 +/- 12.2). At the 6-month follow-up, no statistically significant difference was found between mean GSM (17.8 +/- 7.8) in 47 stenosis-free cases compared with mean GSM (18 +/- 6.8) in 22 cases where severe restenosis (>70%) or reocclusion was identified by DUS scan (P = .4).
  
  
  CONCLUSIONS
  Plaque echogenicity represented by DUS-derived GSM can be used to predict the success of primary subintimal femoral-popliteal angioplasties.
authors.affiliation: Maimonides Medical Center, 4801 10th Avenue, Brooklyn, NY 11219, USA.
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Marks
authors.forename: Enrico
authors.initials: E
authors.lastname: Ascher
authors.forename: Anil P
authors.initials: AP
authors.lastname: Hingorani
authors.forename: Alexander
authors.initials: A
authors.lastname: Shiferson
authors.forename: Alessandra
authors.initials: A
authors.lastname: Puggioni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000009:adverse effects / Q000379:methods; D050197:Atherosclerosis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011150:Popliteal Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D018084:Ultrasonography, Interventional; D014654:Vascular Patency