BACKGROUND:Surgical accuracy is a key to surgical success.The traditional positioning method mainly depends on surgeons' experience,which is too subjective to cause screw misplacement.Three-dimensional (3D) printing technology-assisted pedicle screw placement can make individualized surgical scheme,most importantly,it is accurate and simple showing promising application prospect.OBJECTIVE:To design an individualized pedicle guide plate with 3D printing and to simulate screw placement in vitro,and to explore its feasibility in vertebral pedicle screw placement.METHODS:Lumbar spine CT data of 11 patients with degenerative lumbar spine were selected from April 2016 to July 2016 at Hebei General Hospital,and 3D reconstruction of L1,L3 and L5 vertebrae of each case was performed.Pre-experiment was conducted based on one patient's lumbar CT data:according to the principle of screw placement,the screw position and orientation were designed to prepare the best pedicle guide plate model.Afterwards,the screw placement in vitro was simulated,and was then cut by chainsaw to verify the accuracy of screw placement.RESULTS AND CONCLUSION:(1) A total of 30 pedicle guide plates were used,and 60 screws were inserted in the patients,and the placement process was successful.The guide plates adhered well,none appeared with screw perforating the pedicle cortex,and the screw position was accurate and reliable.(2) There were no significant changes in the transverse section and sagtial section angles of the left and right pedicle screws before and after placement (P ＞ 0.05).(3) These results suggest that the 3D-printed individualized pedicle guide plate holds a good accuracy of placement,which can be applied in the vertebral pedicle screw placement,but further clinical trials are needed.

Gastric schwannoma is a tumor originating from mesenchymal tissue. The clinical incidence is relatively rare, accounting for 6.3% of all gastric stromal tumors. The tumor is more likely to occur in the body of the stomach and usually originates from the gastric submucosal nerve. Most gastric schwannomas do not have any clinical symptoms. Imaging examination can play a diagnostic role, but the diagnosis still requires pathological examination, especially S-100 protein which is the gold standard for the diagnosis of gastric schwannomas. Gastric schwannoma usually needs to be distinguished from gastrointestinal stromal tumors and gastrointestinal autonomic nerve tumors. In terms of treatment, complete surgical resection is the first choice.

Objective:To analyze the clinical effect of real-time virtual sonography (RVS) surgical navigation combined with indocyanine green fluorescence imaging technology in the anatomical liver segmentectomy for hepatocellular carcinoma (HCC).Methods:The clinical data of 35 patients who underwent anatomical liver segmentectomy using RVS surgical navigation combined with indocyanine green fluorescence imaging technology in the Department of Hepatobiliary Surgery of Peking University International Hospital from January 2020 to January 2022 were retrospectively analyzed. There were 22 males and 13 females, aged (60.0±10.0) years. RVS is real-time virtual sonography, which fuses real-time intraoperative ultrasound images with corresponding preoperative CT or MRI images to guide the surgical plane. Methods of operation, time of operation, intraoperative blood loss, operative margin, hospital stay and postoperative complications were analyzed. Postoperative complications were graded by Clavien-Dindo system. The 1-year overall survival and tumor-free survival rates of patients were followed up by outpatient or telephone review.Results:Anatomical liver segmentectomy was performed on 36 patients, including 1 patient (2.9%) of segment Ⅱ, 1 patient (2.9%) of segment Ⅲ, 5 patients (14.3%) of segment Ⅳ, 6 patients (17.1%) of segment Ⅴ, 10 patients (28.6%) of segment Ⅵ, 7 patients (20.0%) of segment Ⅶ, 4 patients (11.4%) of segment Ⅷ, and 1 patient (2.9%) of segments Ⅴ+ Ⅷ. The operation time of 35 patients was (310.2±81.6) min, with an intraoperative blood loss of [ M( Q1, Q3)] 390.0(250.0, 500.0) ml. The hospital stay was (11.6±2.1) d. There was no postoperative death. Postoperative complications occurred in 3 cases (8.6%), of which 2 cases (5.7%) were ascites, Clavien-Dindo grade Ⅰ; Postoperative hemorrhage occurred in 1 case (2.9%), Clavien-Dindo grade Ⅱ. HCC was confirmed by pathology in all cases, and the operative margins were negative. The median follow-up time was 14 months (12 to 20 months). The 1-year overall survival rate after surgery was 100.0%(35/35), three patients (8.6%) had tumor recurrence, and the 1-year tumor-free survival rate was 91.4% (32/35). Conclusion:RVS surgical navigation combined with indocyanine green fluorescence imaging technology could be feasible in anatomical segmental hepatectomy for HCC.