Prantl L, Schreml S, Walter M, Kasprzak P, Stehr A, Nerlich M, Feurbach S, Jung E M
Department of Trauma and Plastic Surgery, University of Regensburg, Regensburg, Germany.
Clin Hemorheol Microcirc. 2008;39(1-4):343-50.
The aim of the prospective study was to evaluate the macro- and microcirculation in the center and periphery of free flaps with high resolution vascular ultrasound.
Fifteen patients with free parascapular flaps after lower limb trauma were examined six months postoperative. All ultrasound investigations were performed by one experienced examiner with a multi-frequency linear transducer (5-9 MHz, Logiq 9, GE). Flow evaluation was angle-optimized using digital image technology with the color coded Doppler sonography (CCDS) with measurement of the peak systolic, peak diastolic flow velocities and the resistance index (RI). Contrast harmonic imaging (CHI) with time intensity curve (TIC) analysis was used for quantitative evaluation of the tissue perfusion. Through a peripheral cubital cannula, a first bolus injection was made of 2.4 ml Sonovue to evaluate the perfusion near the flap center and the distal part of the flap.
The combined analysis of all 15 patients showed in the center and in the periphery of the flap a significant increase (p<0.01; Wilcoxon signed rank test) of the perfusion (relative units = RUs) in the period of 90-120 s after contrast medium application (center: baseline perfusion 2.23+/-0.31 RUs to 5.25+/-0.90 RUs after contrast medium; periphery: baseline perfusion 3.07+/-0.44 RUs to 5.80+/-0.57 RUs after contrast medium). The separate analysis of the non-bypass group (n=9) and bypass group (n=6) showed a clearly higher central flap perfusion after contrast medium application for the bypass group. The combined analysis of all patients showed RI-values amounting to 0.79+/-0.03. The RI-values of the bypass group were significantly higher than RI-values of the non-bypass group (p<0.05; t-test; p<0.05; Mann-Whitney rank sum test).
The high-resolution ultrasound represents an ideal method for detection of the flow and patency of the bypass and the small vessels of the free flap. The patency of microvascular anastomosis as well as the perfusion and microcirculation in different flap territories and tissue layers can be investigated using dynamic contrast-enhanced ultrasound with subtraction modalities.
这项前瞻性研究的目的是使用高分辨率血管超声评估游离皮瓣中心和周边的宏观及微循环情况。
对15例下肢创伤后接受游离肩胛旁皮瓣移植的患者在术后6个月进行检查。所有超声检查均由一名经验丰富的检查人员使用多频率线性换能器（5 - 9 MHz，Logiq 9，GE公司）进行。使用数字图像技术对彩色编码多普勒超声（CCDS）进行角度优化以评估血流，测量收缩期峰值、舒张期峰值流速以及阻力指数（RI）。采用对比谐波成像（CHI）及时间强度曲线（TIC）分析对组织灌注进行定量评估。通过外周肘静脉插管，首次推注2.4 ml声诺维以评估皮瓣中心附近及皮瓣远端的灌注情况。
对所有15例患者的综合分析显示，在应用造影剂后90 - 120 s期间，皮瓣中心和周边的灌注（相对单位 = RUs）显著增加（p<0.01；Wilcoxon符号秩和检验）（中心：造影剂应用前基线灌注为2.23±0.31 RUs，应用后为5.25±0.90 RUs；周边：造影剂应用前基线灌注为3.07±0.44 RUs，应用后为5.80±0.57 RUs）。对非搭桥组（n = 9）和搭桥组（n = 6）的单独分析显示，应用造影剂后搭桥组皮瓣中心灌注明显更高。对所有患者的综合分析显示RI值为0.79±0.03。搭桥组的RI值显著高于非搭桥组（p<0.05；t检验；p<0.05；Mann - Whitney秩和检验）。
高分辨率超声是检测游离皮瓣搭桥血管和小血管血流及通畅情况的理想方法。使用动态对比增强超声及减法模式可研究微血管吻合的通畅情况以及不同皮瓣区域和组织层的灌注及微循环情况。
