数字化技术在隐动脉皮瓣血供的可视化及其临床初步应用

Three-dimensional reconstruction methods in visualization and application of arteria saphena flaps

目的探讨数字化技术在隐动脉皮瓣血供的可视化及其临床初步应用。方法明胶一氧化铅混悬液灌注的新鲜成人尸体标本2具，进行16排多层螺旋cT全身连续扫描，提取大腿二维灰度．dicom格式图像并导入Amira5．4．1软件，对隐动脉结构进行三维重建并立体显示，确定构建隐动脉皮瓣的范围。对2010年6月至2011年8月收治的6例（6侧）胫前皮肤缺损、骨外露患者进行64排螺旋cT扫描，将扫描．dicom格式图像导入Mimics14．0软件，对大腿和膝关节血管、特别是膝降动脉和隐动脉进行连续观察，三维表面重建隐动脉并测量，根据患者创面缺损面积进行个性化隐动脉皮瓣三维构建，再应用于临床治疗。结果6例患者获8～24个月（平均18个月）随访，重建的数字化模型可准确反映隐动脉的解剖学结构。所有患者显示的皮瓣为主要穿支及主干，隐动脉起点到膝关节间隙的平均距离为（119．2±9．6）mm，隐动脉起点直径平均为（1．5±0．3）mm；本组皮瓣切取范围为8．0cm×5．0cm～20．0cm×8．0cm；皮瓣及供区植皮均顺利成活，膝关节屈曲120°～140°伸直0～10°。结论采用数字化三维重建技术可以提供隐动脉三维动态解剖，为临床应用隐动脉皮瓣移植提供了可能。

Objective To discuss the digital technique used in visualization of arteria saphena flaps and its clinical applications. Methods Two adult fresh cadaveric specimens, one male and one female, were subjected to radiographic CT scanning before and after perfusion with lead oxide-gelatine mixture, with collimation of 0. 625 mm （120 kV, 110 mA, 512 x512 matrix）. Through Amira 5.4. 1 software, the 2D CT images in. dicom format were transformed into 3D models of the entire region. Structures of the arteria saphena were observed and visible digital models of the arteria saphena flap were established through 3D computerized reconstruction by Amira 5.4. 1 software. Next 6 patients with soft-tissue defects and bone exposure at the tibial region underwent contrast-enhanced CT angiography of the lower limb by a 64-row multi-slice spiral CT ma- chine after median cubital vein injection with Uhravist （3.5 mL/s）. The 2D CT images in . dicom format of the patients were transformed into individualized 3D reconstruction models of the arteria saphena flap using Mimics 14. 0 software. The digital design of the individualized arteria saphena flap was used in clinic. Results All the 6 patients were followed up for an average of 18 months （from 8 to 24 months） . The 3D reconstruction visible models established from the CT datasets perfectly displayed anatomy of the arteria saphena flap. In the 6 cases the main trunk and branches of the blood vessels in the designed flap were consistent with the surgical findings. The average distance from the starting point of the arteria saphena to the knee clearance was 119.2± 9.6 mm and the average diameter of the arteria saphena at the starting point was 1.5± 0.3 mm. The areas of flap ranged from 8.0 cm ×5.0 cm to 20. 0 cm× 8.0 cm All flaps survived well. The knee flexion was 120° to 140° and the knee extension 0° to 10°. Conclusion The 3D reconstruction models can provide perfect dynamic visualization of the anatomy of the arteria saphena which can be successfully used in clinic in individualized design of the arteria saphena flap to be transplanted for a specific patient.