Study On Application Of Personal Three-dimensional Model Of Liver And Virtual Liver Resection In Hepatectomy

Objective:To explore the clinical value of virtual hepatic resection using three-dimensional (3D) models reconstructed from computed tomography images on planning for hepatectomy.Methods:Two-dimentional (2D) CT image data of the liver were obtained from twenty patients for whom hepatectomies were planed. After transmission of CT images to the3D simulation system(IQQA-liver, EDDA, U.S.A),the software was programmed to reconstruct detailed3D structure of the tumor, portal vein, hepatic vein, and liver parenchyma. A radiologist performed the virtual hepatectomy simulation under the guidance of two experienced hepatic surgeons who were in the same group with the operating surgeon, followed by automatic calculation of the total liver volume,resected and residual volume,and subsequently to guide the planning of hepatectomies and compare the whole process of the simulation process and real surgery.The agreement and difference between the two observers’calculation in determining resected volumes was assessed.For validation, predicted resection volumes were compared with actual resected specimen volumes(It was determined by means of water displacement).Results:l.The liver parenchyma, tumor, intrahepatic vessels were well segmented in3D models and then the hepatectomy simulations were conducted successfully in all the20cases.Preoperative evaluation of virtual hepatectomy showed that all hepatic neoplasms could be removed.The overlap between the plane of the intraoperative resection and virtual liver resection was remarkable.It can also provide detailed volumetric analyses based on portal perfusion, and quantitative estimates of the venous drainage area and predict the congestion area which could be as a criterion for the venous reconstruction.2.There was significant agreement between the two observers’calculation in determining resected liver volumes (r=0.998;p=0.000). There was no statistically significant difference between the two observers’calculation in measuring resected liver volumes (t=0.197,p=0.846). There was significant agreement between predicted resection volumes measured by each observer and the actual resected specimen volumes obtained at surgery (r=0.966and0.971for observers1and2, respectively; p=0.000).3.The mean time to reconstruct the liver,tumor as well as the intrahepatic vessels for one patient using IQQA-liver was about40-50min.The time to complete virtual hepatectomy simulation for one patient using IQQA-liver was about20-30min.Conclusions:IQQA-Liver is capable of acquiring individual anatomical knowledge prior to hepatic resections.Liver volumetry based on the hepatectomy simulation is an accurate method for predicting resection volume and the future liver remnant volume.This virtual method makes a great significance in guidance for liver resection planning and should contribute to prevent postoperative hepatic failure and reduce postoperative complications,also improve the security of hepatectomy.