With advances in early diagnosis and treatment of lung cancer and the widespread adoption of low-dose computed tomography (LDCT), CT-guided percutaneous lung localization has become a key technique for the precise marking of small, deep, or radiologically occult lesions before video-assisted thoracoscopic surgery (VATS). It provides surgeons with visual or tactile guidance during VATS procedures, enabling rapid diagnosis and treatment of pulmonary nodules while avoiding the need for conversion to open surgery due to localization failure or excessive resection (1–3). The growing availability of hybrid operating rooms has further promoted an integrated “one-stop” diagnostic and therapeutic approach, enabling seamless transition from localization under general anesthesia to surgical resection (4, 5). This model mitigates the risks and logistical delays associated with patient transfer following conventional local anesthesia-based localization performed in standard CT suites. Studies indicate that approximately 53% of patients experience moderate-to-severe pain during localization under local anesthesia (6). Performing the procedure under general anesthesia significantly alleviates anxiety and discomfort, reduces motion-related complications, and improves targeting accuracy. Although minimally invasive and efficient, the technique carries risks such as pneumothorax, hemorrhage, and gas embolism. The latter, though rare, can lead to myocardial infarction, stroke, or even death (7). Sometime it will cause huge economic losses, data from the American Society of Anesthesiologists Closed Claims Project showed 100% of claims for gas embolism resulted in a median payment of $325,000 (8). The reported incidence of clinically apparent gas embolism ranges from 0.061 to 0.49%, while the asymptomatic incidence may be as high as 3.8–4.8% (7, 9–11). Due to its often subtle or absent clinical presentation, this complication is often overlooked. This article presents three cases of gas embolism occurring during CT-guided lung localization under general anesthesia, aiming to enhance clinical recognition and management of this serious complication and to improve patient outcomes.

Systemic gas embolism represents a rare but serious complication of CT-guided percutaneous lung puncture localization. Its incidence rate in imaging diagnosis is significantly higher than that in clinical symptom diagnosis (4.8% vs. 0.17%) (10), and it may lead to catastrophic outcomes such as acute ischemic stroke, myocardial infarction, or death. The mechanism of systemic gas embolism following percutaneous lung puncture involves gas entering the pulmonary veins, passing through the left atrium and left ventricle, and ultimately entering the systemic circulation. Three principal pathways have been proposed for air entry into the pulmonary vein (12): (1) direct introduction through the puncture needle; (2) concurrent alveolar and venous penetration with pressure-driven gas influx; and (3) retrograde passage from the pulmonary artery to the pulmonary vein through pulmonary microcirculation or pre-existing arteriovenous malformations. The most dangerous consequence is when gas enters the coronary arteries and cerebral blood vessels: coronary events manifest as acute ischemia (chest pain, syncope, cardiac arrest), while cerebral involvement causes neurological deficits (sensory loss, aphasia, seizures). Embolization to other vascular territories can lead to hemodynamic instability, urinary retention, respiratory distress, or hemoptysis. In all three cases presented here, inadvertent injury to pulmonary veins adjacent to the target lesion could not be excluded as a contributing factor.

Proactive prevention remains essential. Key measures include ensuring the target lesion lies below the left atrial level, utilizing breath-hold techniques during needle placement, avoiding vascular structures and minimizing puncture attempts, and implementing post-procedural CT or MRI surveillance for early detection (13, 14). In the event of gas embolism, prompt intervention is essential to mitigate severe complications (15). Recommended measures include immediate repositioning of the patient into the supine or Trendelenburg position (with head lowered 15 to 30°) to facilitate air trapping in the right ventricle and prevent systemic embolization. Concurrently, administration of 100% oxygen is advised, as it enhances nitrogen washout and accelerates the elimination of air bubbles from the circulation. Hyperbaric oxygen therapy represents the most effective treatment for cerebral infarction resulting from air embolism, acting by increasing ambient pressure to reduce bubble volume and promote gas dissolution. This intervention should be initiated as early as possible (16, 17); however, it is contraindicated in patients with significant emphysema, bullae, or active pneumothorax.

Analysis of these three cases provides important insights into the advantages and challenges of CT-guided percutaneous lung localization under general anesthesia. Conducting the procedure in a hybrid operating room facilitates immediate resection following localization, eliminating delays associated with inter-departmental transfer and enhancing workflow efficiency. General anesthesia minimizes patient anxiety and pain, thereby reducing risks of needle displacement or repeated punctures. In cases of gas embolism, contralateral one-lung ventilation can be initiated promptly to limit systemic gas entry, while positional adjustments such as the Trendelenburg position help redirect intracardiac air. The fully equipped operating environment also enables timely resuscitation in the event of severe complications such as arrhythmia, hypotension, or cardiac arrest. However, we also identified shortcomings in handling these three cases: Regarding Case 1, due to a lack of timely communication with the surgeon and radiologist, we only recognized the occurrence of gas embolism when the patient developed severe hypotension during surgical sterilization and rapidly progressed to cardiac arrest requiring resuscitation. Case 2: Repeated puncture increased the risk of complications such as bleeding and air embolism although left ventricular gas embolism was detected promptly, but the patient’s stable vital signs during general anesthesia led to the oversight that gas had entered the cerebral circulation. The patient’s position was not adjusted when gas embolism occurred, and hyperbaric oxygen therapy was not administered postoperatively. Consequently, the patient developed sequelae of cerebral embolism. In contrast, Case 3 utilized a double-lumen tube for selective ventilation, enabling prompt intervention and an uneventful recovery.

In conclusion, highlights the critical role of meticulous surgical techniques, close radiological monitoring, and timely anesthetic intervention in reducing the risk of gas embolism and related sequelae. First, CT-guided percutaneous lung puncture localization may lead to serious complications such as air embolism. Currently, preoperative auxiliary localization techniques for pulmonary small nodules continue to evolve, with the increasing adoption of robotic bronchoscopy and electromagnetic navigation bronchoscopy. These bronchoscopic approaches avoid crossing the pleura and lung parenchyma, reducing the possibility of direct vascular injury and thereby lowering the incidence of pneumothorax and systemic air embolism. However, these techniques still have limitations such as high cost, operational complexity, time consumption, a steep learning curve, and reliance on multidisciplinary collaboration (18). Therefore, it is recommended that medical institutions select appropriate preoperative localization methods based on their specific conditions to reduce postoperative complications. Regardless of the localization technique used, it must be performed by an experienced surgeon with proficient skills. In the case of CT-guided percutaneous lung puncture localization, repeated punctures should be avoided. For example, in Case 2, four punctures were required to successfully mark the lesion, which undoubtedly increased the risk of bleeding and air embolism. In our institution, the current basic approach adopted is to use disposable pulmonary nodule localization needles for percutaneous lung puncture positioning under CT guidance for lung puncture positioning. The average number of punctures for successful localization is typically 1–3, but the actual number depends on nodule characteristics (size, location, depth) and operator experience. Secondly, effective interdisciplinary communication is essential. Strengthening collaboration among surgeons, radiologists, and anesthesiologists facilitates earlier detection and management of gas embolism. Finally, with the growing use of hybrid operating rooms, general anesthesia is increasingly preferred due to its workflow efficiency and enhanced patient comfort. Under local anesthesia, patients breathe room air, in which the high nitrogen content delays gas absorption. In contrast, patients under general anesthesia receive pure oxygen throughout the procedure. In the event of embolism, immediate initiation of single-lung ventilation, combined with absorption of pure oxygen, may help reduce postoperative complications (it is noteworthy that in Case 2, the patient did not receive pure oxygen after intubation). Although general anesthesia with tracheal intubation has been identified as a potential risk factor for systemic gas embolism (19)—because positive-pressure ventilation may facilitate gas entry into injured pulmonary veins—high-quality evidence directly comparing general and local anesthesia in this context remains limited. Based on current experience, we recommend that during needle localization under general anesthesia, a double-lumen endotracheal tube or bronchial blocker should be routinely used, accompanied by ventilation with 100% oxygen. Specifically, after airway fixation and lung preoxygenation, one-lung ventilation is maintained on the non-operative side during puncture, while a continuous positive airway pressure (CPAP) of 5 cmH₂O with 100% oxygen is applied to the operative lung. This strategy not only maintains lung expansion but also ensures a low and stable intrapulmonary pressure, significantly lower than pulmonary venous pressure. Theoretically, this pressure gradient helps reduce the risk of a large volume of gas entering the systemic circulation during venous puncture. Since implementing this protocol, no severe gas embolism events have been observed in our institution, though its efficacy requires further validation.

Although rare, gas embolism secondary to CT-guided percutaneous lung biopsy can be fatal. While general anesthesia facilitates the procedure, it may also introduce specific risks, necessitating further investigation to fully delineate its safety profile. Based on our experience, the following measures are critical for enhancing safety under general anesthesia: Initiate 100% oxygen ventilation following intubation, maintain single-lung ventilation on the non-operative side during puncture, and apply continuous positive airway pressure (CPAP) at 5 cmH₂O to the operative lung. Minimize the number of puncture attempts to reduce tissue and vascular injury. Perform immediate post-procedural CT imaging in close collaboration with the radiology team to enable early detection of intravascular air. Upon suspicion or confirmation of embolism, promptly reposition the patient (e.g., Trendelenburg) to limit further gas entry into the systemic circulation. In summary, whether under general or local anesthesia, the consistent identification of high-risk scenarios, proactive prevention, and timely intervention remain essential to mitigating complications during CT-guided lung localization.