In recent years, the resection of lung segments emerged as an effective treatment option for early detection of pulmonary nodules, but the complex anatomy and variability of lung segments make precise resection of lung segments more difficult [4, 5]. It is extremely difficult to find intraoperatively for deeply located, smaller, subsolid nodules [6, 7]. It became a hot topic of research for thoracic surgeons about the appropriate methods of removing lung segments precisely and effectively and improving the successful rate and safety of surgery. In this study, our objective was to investigate the potential clinical benefits of utilizing preoperative 3D reconstruction with CT-guided Hook-wire localization in the treatment of pulmonary nodules.

The CT-guided Hook-wire pulmonary nodule localization method involves inserting a steel needle visible to the naked eye around the pulmonary nodule, reading the chest CT after localization, and determining the location of the Hook wire and the pulmonary nodule to achieve rapid intraoperative location of the lesion. However, it is an invasive operation that can lead to complications such as pneumothorax, hemothorax, and decubitus. Two cases of pneumothorax occurred in the Hook-wire group in this study, which is probably related to the patient’s emphysema and repeated punctures. As a small amount of pneumothorax, neither of which was treated specifically. Previous literature reported that the incidence of pneumothorax was approximately 35% [8], which is asymptomatic and usually does not require treatment. We have thoracentesis kits available in the CT puncture room, and once a large pneumothorax is confirmed, closed chest drainage is performed promptly. Three cases of hemothorax occurred in the Hook-wire group, which presumably results from the injury to the intercostal vessels and pulmonary peripheral vessels during the puncture route. The thin Hook-wire puncture needle, along with thin intercostal and peripheral pulmonary vessels, increases the risk of such bleeding. We performed the puncture within 2 h before the procedure, and the bleeding time was short, and the bleeding caused by the puncture was small, so no special treatment was needed. If shock manifestations such as rapid heart rate and low blood pressure occur, promptly transfuse blood and send to the operating room for resuscitation. Four cases of uncoupling occurred in the Hook-wire group. It is mainly because the pulmonary nodules were close to the pleura and the barb end did not enter the lung completely when the wire was released during CT-guided Hook-wire puncture, resulting in the inability to open the barb. In this situation, the surgeon adds an appropriate amount of sterile water to the chest cavity, instructs the anesthesiologist to drum the lung, identifies the pinhole on the pleural surface, and successfully determines the location of the pulmonary nodule by the position of the Hook-wire pinhole. No complications such as pneumothorax, hemothorax, or decortication occurred in the 3D reconstruction group in this study. This localization method confirms the location of the pulmonary nodule under direct vision during procedure. There is no invasive manipulation during localization and no damage to the intrathoracic structures. To avoid tumor dissemination caused by puncture needles, additional costs associated with invasive procedures and patient pain and anxiety due to puncture positioning. For lung nodules in special locations, such as the pulmonary apex and scapular region, it is more difficult to localize them using Hook wire due to the obstruction of important blood vessels, nerves, and scapulae in the chest wall. However, these specifically located pulmonary nodules have more anatomical landmarks (marker points) on the lung surface. Therefore, the 3D reconstruction pulmonary nodule localization method has unique advantage of specifically located pulmonary nodules.

Three patients in the 3D reconstruction group in this study failed localization, mainly because of severe adhesions in the chest cavity, and the anatomical marker lines (marker points) on the lung surface were destroyed when separating the adhesions. We performed a complete surgical resection of the pulmonary nodule using finger touch as a complementary method. In the case of pleural adhesions, the anatomical position of the lung is altered, and bleeding leads to blurred visualization, making it difficult to distinguish the anatomical landmarks (marker points) on the lung surface. There are relatively few anatomical markers (marker points) on the lung surface in the ribbed surface of the lower lung, making localization difficult using this method [9]. So careful preoperative interpretation of the location of the pulmonary nodule is required. And for pulmonary nodules in this location, CT-guided Hook-wire pulmonary nodule localization is recommended to facilitate rapid intraoperative location of the pulmonary nodule.

This study found that the 3D reconstruction group has significantly shorter operative time, less intraoperative bleeding, less total postoperative chest drainage, and shorter postoperative hospital stays than the Hook-wire group. By studying 3D reconstructed images, surgeons can accurately understand the 3D spatial structure of blood vessels and bronchi before surgery and identify anatomical variants beforehand. Compared to the normal pattern of vascular and bronchial distribution, 3D reconstruction allows earlier evaluation and avoids dissecting more unnecessary lung tissue. Although no anatomical variant vessels were found in the 3D reconstruction group in this study, the target vessels and trachea could be more accurate identification preoperatively, which shortened the intraoperative recognition time of the structures and provided a good assessment of the vascular alignment. It effectively reduces the probability of inadvertent injury and disconnection of intrapulmonary vessels and trachea; reduces excessive freeing of tissues, smaller surgical invasion; and very well shortens the operation time.

Other methods for pulmonary nodule localization include CT-guided coil placement and medical adhesive localization [10]. Spring coil localization is a simple, quick, and highly accurate method but may lead to complications such as lung infection or bleeding during the retention process [11]. Medical adhesive can rapidly solidify inside the body to ensure accurate positioning while also blocking cut blood vessels and promoting blood coagulation, thereby reducing air leakage and bleeding caused by puncture. However, medical adhesive has some drawbacks, including its pungent odor, which can cause discomfort such as coughing in patients. If injected too quickly, it may even cause pulmonary embolism [12]. With the development of digital medical imaging technology, 3D reconstruction techniques have been widely used in various aspects of preoperative assessment of thoracoscopic precision lung segment resection, localization of lung nodules, simulation of surgical protocols, and intraoperative guidance for identification of bronchi and pulmonary vessels [9, 13, 14]. In the era of medicine that emphasizes individualized treatment, preoperative 3D reconstruction images can be used to quickly and intuitively identify individual anatomical patterns through a 360-degree view and observation and judgment from multiple levels and angles, which is an important guarantee for accurate lung segment resection. Compared with CT-guided Hook-wire localization, 3D reconstructed images are cheaper and easier for patients to accept. However, there are limitations to 3D reconstruction guiding surgery. For instance, the lung on the preoperative chest CT scan may be distended and in a normal position, while the lung on the operative side collapses and retracts during thoracoscopic surgery. Therefore, the path of bronchial and vascular travel in the lung segment differs between the two conditions, which requires experience to accurately identify. In addition, 3D reconstruction needs to be completed by surgeons and radiologists who are skilled in the application of relevant software.

This study has certain drawbacks and shortcomings: (I) because the data source included in the study is a single center with limited sample size results and is a retrospective study, which may lead to bias, and (II) the study focused on short-term clinical outcomes in the perioperative period. Hence, further long-term follow-up reviews are necessary to compare and analyze the differences in long-term clinical outcomes between the two groups.