Optimization of computer-assisted surgical access during the retroperitoneal endoscopic ureterolithotomy using the patient coordinated 3D reconstruction of the operation area

Introduction. Three-dimensional modeling of the retroperitoneal cavity could be used for the pre-operative planning of the surgery. An optimal method, which could let to coordinate the 3D model with the patient’s body, is still lacking, though it could be perspective for the minimally-invasive surgery, for example, in case of the retroperitoneal endoscopic ureterolithotomy (REULT). Materials and methods. We have developed the apparatus / software complex, by means of which it is possible to create the virtual model of the operation area based on the computed tomography (CT) data and to select the optimal access points and prevent possible damage to other structures. After coordination of the model with the patient’s body using the mechanic 3D digitizer optimal access points are being selected. Results. REULT was performed in 17 patients using the mentioned method, among which there were 8 men and 9 women. Mean age was 39.5 (25-56) years. Mean stone size according to CT was 9 (7-14) mm. Mean operation time was 39.5 (25-55) min. Mean blood loss was 50.0 (10-90) ml. In all patients primary wound closure was effective. Mean hospital stay was 5.5 (4-7) days. Conclusions. An optimal access selection for the surgical intervention based on the 3D model of the operation area and co-ordination of the data with patient’s body was effective during the REULT. This method could be used for other operations in the region of the retroperitoneum and also for teaching purposes.