title: [Clinical values of hemodynamics assessment by parametric color coding of digital subtraction angiography before and after endovascular therapy for critical limb ischaemia].
abstract: OBJECTIVE
  To investigate the feasibility of parametric color coding of digital subtraction angiography (Syngo iFlow) for hemodynamics assessment in patients with critical limb ischemia in pre- and post-endovascular therapy. To explore the correlation between Syngo iFlow and the conventional techniques.
  
  
  METHODS
  from January 2013 to December 2014, Clinical data of 21 patients with TASC II type B and type C femoropopliteal arteriosclerotic occlusive disease who were treated by percutaneous transluminal angioplasty and/or primary stent implantation in Nanjing first hospital were analyzed retrospectively. Of these patients there were 10 males and 11 females with an average age of (72±6) years (range from 58-85 years). The treatment efficacy was assessed by the variation of a series of clinical symptoms indexes (such as pain score, cold sensation score and intermittent claudication score), ankle braehial index (ABI) and transcutaneous oxygen pressure (TcPO2). Angiography was performed with the same protocol before and after treatment and parametric color coding of digital subtraction angiography was created by Syngo iFlow software on a dedicated workstation. The time to peak (TTP) of artery and tissue perfusion selected at the same regions of foot and ankle were measured and analyzed to evaluate the improvement of microcirculation and hemodynamics of the ischemic limb. The correlations between Syngo iFlow and the traditional clinical evaluation methods were explored using the Spearman rank correlation test.
  
  
  RESULTS
  All patients (21 limbs) underwent successful endovaseular therapy. The mean pain score, cold sensation score, intermittent claudication score, ABI and TcPO2 before treatment were (0.48±0.68), (2.71±0.72), (2.86±0.85), ABI (0.33±0.07), TcPO2 (26.83±3.41) mmHg. While 1 week after treatment all above indicators were (2.57±0.93), (0.33±0.48), (0.90±0.54), (0.69±0.11), TcPO2 (53.75±3.60) mmHg respectively. There were significant statistical differences between pre- and post-treatment (P<0.05). The pre- and post-operative TTP of artery and tissue perfusion were (14.07±1.77) vs (10.43±2.05) s, (18.75±2.72) vs (15.38±2.78) s. For assessment of hemodynamic changes during and after treatment, parametric color coding of digital subtraction angiography (Syngo iFlow) was assumed to show the limb blood flow and perfusion were improved and the differences were statistically significant. The Spearman rank correlation test showed the TTP of artery was positively correlated with ABI, TcPO2 (r=0.65, 0.73, P<0.05), the TTP of tissue perfusion was also positively correlated with ABI, TcPO2 (r=0.60, 0.60, P<0.05).
  
  
  CONCLUSIONS
  Parametric color coding of digital subtraction angiography (Syngo iFlow) is a real-time, sensitive and quantitative tool that might provide additional support in the hemodynamics evaluation of endovascular treatment for patients with lower extremity peripheral arterial occlusion disease.
authors.affiliation: Department of Interventional Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China.
authors.forename: Haobo
authors.initials: H
authors.lastname: Su
authors.affiliation: Department of Interventional Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China.
authors.forename: Wensheng
authors.initials: W
authors.lastname: Lou
authors.affiliation: Department of Interventional Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China; Email: cjr.gujianping@vip.163.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Gu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D000842:Ankle; D003116:Color; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007511:Ischemia; D035002:Lower Extremity; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome