Preliminary study of a novel method for conveying corrected image volumes in surgical navigation

Precise Navigation of the Surgical Plane with Intraoperative Real-time Virtual Sonography and 3D Simulation in Liver Resection

The precise intraoperative navigation of the surgical plane remains challenging in liver surgery; however, an innovative imaging technique-real-time virtual sonography (RVS)-may provide a solution. In this modality, preoperative three-dimensional (3D) resection simulation data are transmitted to an RVS workstation and can be used in combination with intraoperative ultrasound to navigate the surgical plane in real time. This paper describes this technique and our experiences in detail. From November 2015 to March 2017, 26 patients with primary liver cancer underwent liver resection under RVS navigation. The operative procedures employed included hemihepatectomy, bisegmentectomy, segmentectomy, and limited resection. RVS was utilized uneventfully and successfully in each operation. The median time required for spatial position registration was 3 (1-12) min, and as the case volume increased, the time required for registration markedly decreased. The surgical plane under RVS navigation was consistent with that of the preoperative plan, and the resection margin was confirmed negative in each case. In conclusion, RVS in combination with 3D simulation is a feasible, safe, and promising technique for the precise intraoperative navigation of liver resection for primary liver cancer. It could be applied to other resectable liver diseases and may be utilized in other centers.

Initial experience of intraoperative three-dimensional navigation for liver resection using real-time virtual sonography

BACKGROUND

Real-time virtual sonography is an innovative imaging technology that detects the spatial position of an ultrasound probe and immediately reconstructs a section of computed tomography (CT) and/or magnetic resonance in accordance with the ultrasound image, thereby allowing a real-time comparison of those modalities. A novel intraoperative navigation system for liver resection using real-time virtual sonography has been devised for the detection of tumors and navigation of the resection plane.

METHODS

Sixteen patients with hepatic malignancies (26 tumors in total) were involved in this study, and the system was used intraoperatively. The tumor size ranged 2 to 140 mm (23 mm in median). By the navigation system, operators could refer intraoperative ultrasound image displayed on the television monitor side-by-side with corresponding images of CT and/or magnetic resonance. In addition, the system overlaid preoperative simulation on the CT image and highlighted the extent of resection so as to navigate the resection plane. Because the system used electromagnetic power in the operation room, the feasibility and safety of the system was investigated as well as its validity.

RESULTS

The system could be used uneventfully in each operation. All of the 26 tumors scheduled to be resected were detected by the navigation system. The weight of the resected specimen correlated with the preoperatively simulated volume (R = 0.995, P < .0001).

CONCLUSION

The feasibility and safety of the navigation system were confirmed. The system should be helpful for intraoperative tumor detection and navigation of liver resection.