Three-dimensional visual assessment and virtual reality study of centrally located hepatocellular carcinoma on the axis of blood vessels

Abstract

Objective: To explore a novel method for preoperative precision assessment of centrally located hepatocellular carcinoma(HCC) with blood vessel as axis based on three-dimensional(3D) visualization and virtual reality(VR) technology and its application values. Methods: High-quality thin-layer enhanced CT data were collected from 20 patients with centrally located HCC who treated at First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University from March 2017 to August 2018 diagnosed by preoperative examination. There were 18 males and 2 females, aged 28 to 69 years, all of Child-Pugh grade A. First of all, 3D reconstruction was performed by a 3D visualization software; then, the reconstructed 3D image was imported into VR development engine for VR research; afterwards, the analysis and evaluation system with blood vessel as axis was established based on 3D visualization classification of centrally located HCC; therefore, the relationship of the tumor to its major peripheral blood vessels was accurately judged and the surgical planning was formulated. Two images were brought into the operating room for navigation in surgery. The assessments results of preoperative data (CT and (or) MRI) and three-dimensional visualization of blood vessels in VR environment were compared; the values of the preoperative and postoperative hemoglobin, serum albumin and bilirubin were recorded and compared. Chi-square test, t-test and non-parametric test were used for the analysis of counting data, continuous measurement data and non-normal distribution measurement data, respectively. Results: 3D visualization modeling was completed in all of the 20 patients with centrally located HCC. According to the results of 3D visualization classification of centrally located HCC, there were 3 cases of type Ⅰ,1 case of type Ⅱ,4 cases of type Ⅲ,7 cases of type Ⅳ and 5 cases of type Ⅴ; according to the assessment and classification based on blood vessel as the axis, there were 6 cases of type Ⅰa,2 cases of type Ⅰb,2 cases of type Ⅱa,9 cases of type Ⅱb and 1 case of type Ⅱc. All patients underwent successful resection of tumor under the guidance of 3D visualization and VR technology. There were 15 cases whose assessment results based on preoperative CT/MRI were consistent with intraoperative findings, with a coincidence rate of 75.0%(15/20); while in VR environment, the assessment results of 3D visualization with blood vessel as axis were all consistent with the intraoperative findings, with coincidence rate of 100%(20/20). There was a statistically significant difference between the groups (χ(2)=5.714, P=0.017). There was no red blood cell transfusion in all patients during the operation. The preoperative hemoglobin was (128.8±14.9)g/L, and it was (119.8±12.5)g/L on postoperative day 1. There was no significant difference between these two sets of data (t=2.07, P=0.054). No death during the perioperative period and no complications such as hepatic failure, hemorrhage and biliary fistula after operation occurred. Conclusion: Preoperative evaluation based on 3D visualization and VR technology with blood vessel as the axis has significant clinical value for preoperative planning and surgical navigation of centrally located HCC.