The application value of computed tomography in combination with intraoperative noninvasive percutaneous ultrasonic localisation of subpleural pulmonary nodules/ground-glass opacity in uniportal video-assisted thoracoscopy

Introduction
This study investigates the application value of preoperative noninvasive computed tomography (CT) localisation, combined with intraoperative percutaneous ultrasonic localisation, in the precise positioning and excision of subpleural pulmonary nodules/ground-glass opacity in uniportal video-assisted thoracoscopic surgery (U-VATS).

Aim
To derive the precise positioning and excision of subpleural pulmonary nodules by CT combined with intraoperative percutaneous ultrasonic localisation and to avoid the complications caused by preoperative CT-guided puncture localisation, reduce physiological and psychological stress such as anxiety, CT radiation dose, and treatment cost, and to improve the treatment satisfaction of patients.

Material and methods
A total of 54 patients with subpleural pulmonary nodules/ground-glass opacity (SPN/GGO), who were treated in our hospital from June 2017 to January 2020, were enrolled in this study. The patients were randomly divided into a treatment group (n = 23), and the nodules were scanned by high-resolution CT and marked at the shortest distance on the surface of the body prior to surgery. These pulmonary nodules were relocated by ultrasound at the original CT positioning points in the same body position following the administration of general anaesthesia. Then, the hookwire puncture location was performed under real-time guidance. For the control group (n = 31), the subpleural pulmonary nodules were located by CT-guided puncture and embedding a hookwire prior to surgery. Pulmonary wedge resection was performed by U-VATS in each group. The subpleural nodules were confirmed by the naked eye and rapid pathological diagnosis after surgery. The difference in positioning success rate, positioning time, the incidence of complications, and patient anxiety scores for subpleural pulmonary nodules were compared and analysed between the two groups.

Results
A total of 22 cases of subpleural nodules were successfully located in the treatment group at a success rate of 95.6% (22/23). The average positioning time for CT in combination with ultrasound was 22.0 ±5.9 min. In the control group, 31 cases of subpleural pulmonary nodules were satisfactorily located at a success rate of 100% (31/31). The average positioning time of CT was 24.2 ±5.4 min. The difference in positioning success rate and positioning time was not statistically significant (p = 0.24; p = 0.15) between the two groups. The incidence of complications and SAS anxiety scores in the treatment group were lower compared with the control group. The difference was statistically significant (p = 0.002; p < 0.001).

Conclusions
Preoperative CT combined with intraoperative percutaneous real-time noninvasive ultrasonic localisation can accurately locate subpleural pulmonary nodules, with a high degree of safety and good tolerance in patients who are suitable for U-VATS.