Nonfatal air embolism complicating percutaneous CT-guided lung biopsy and VATS marking: Four cases from a single institution

Optimizing Precision: A Trajectory Tract Reference Approach to Minimize Complications in CT-Guided Transthoracic Core Biopsy

The advent of computed tomography (CT)-guided transthoracic needle biopsy has significantly advanced the diagnosis of lung lesions, offering a minimally invasive approach to obtaining tissue samples. However, the technique is not without risks, including pneumothorax and hemorrhage, and it demands high precision to ensure diagnostic accuracy while minimizing complications. This study introduces the Laser Angle Guide Assembly (LAGA), a novel device designed to enhance the accuracy and safety of CT-guided lung biopsies. We retrospectively analyzed 322 CT-guided lung biopsy cases performed with LAGA at a single center over seven years, aiming to evaluate its effectiveness in improving diagnostic yield and reducing procedural risks. The study achieved a diagnostic success rate of 94.3%, with a significant reduction in the need for multiple needle passes, demonstrating a majority of biopsies successfully completed with a single pass. The incidence of pneumothorax stood at 11.1%, which is markedly lower than the reported averages, and only 0.3% of cases necessitated chest tube placement, underscoring the safety benefits of the LAGA system. These findings underscore the potential of LAGA to revolutionize CT-guided lung biopsies by enhancing procedural precision and safety, making it a valuable addition to the diagnostic arsenal against pulmonary lesions.

Enhancing precision in lung tumor ablation through innovations in CT-guided technique and angle control

BACKGROUND

This retrospective study aimed to evaluate the precision and safety outcomes of image-guided lung percutaneous thermal ablation (LPTA) methods, focusing on radiofrequency ablation (RFA) and microwave ablation (MWA). The study utilized an innovative angle reference guide to facilitate these techniques in the treatment of lung tumors.

METHODS

This study included individuals undergoing LPTA with the assistance of laser angle guide assembly (LAGA) at our hospital between April 2011 and March 2021. We analyzed patient demographics, tumor characteristics, procedure details, and complications. Logistic regressions were employed to assess risk factors associated with complications.

RESULTS

A total of 202 patients underwent ablation for 375 lung tumors across 275 sessions involving 495 ablations. Most procedures used RFA, especially in the right upper lobe, and the majority of ablations were performed in the prone position (49.7%). Target lesions were at a median depth of 39.3 mm from the pleura surface, and remarkably, 91.9% required only a single puncture. Complications occurred in 31.0% of ablations, with pneumothorax being the most prevalent (18.3%), followed by pain (12.5%), sweating (6.5%), fever (5.0%), cough (4.8%), hemothorax (1.6%), hemoptysis (1.2%), pleural effusion (2.0%), skin burn (0.6%), and air emboli (0.2%). The median procedure time was 21 min. Notably, smoking/chronic obstructive pulmonary disease emerged as a significant risk factor for complications.

CONCLUSION

The LAGA-assisted LPTA enhanced safety by improving accuracy and reducing risks. Overall, this investigation contributes to the ongoing efforts to refine and improve the clinical application of these thermal ablation techniques in the treatment of lung tumors.

Air embolism after CT-guided localization of pulmonary ground-glass nodules

OBJECTIVE

To investigate the incidence of air embolism (AE) related to CT-guided localization of pulmonary ground-glass nodules (GGNs) prior to video-assisted thoracoscopic surgery (VATS).

METHODS

The data of all patients who received CT-guided localization of GGNs before VATS from May 2020 to October 2021 were retrospectively analyzed.

RESULTS

A total of 1395 consecutive patients with 1553 GGNs were enrolled. AEs occurred in seven patients (0.5%). In four of the seven patients with AE, the embolism was detected before the patients left the CT table and emergency treatments were carried out. Among them, one patient had chest tightness and unilateral limb dyskinesia, one patient had convulsions and transient loss of consciousness, and two patients had no definite clinical symptoms. After a short-term high-flow oxygen inhalation, the clinical symptoms of two patients with symptomatic AE disappeared and two patients with asymptomatic AE did not show any symptoms. In the remaining three patients with AE, the embolism were detected retrospectively when evaluating the images in the PACS for this study. Fortunately, these three patients never developed clinical symptoms related to AE. All seven patients with AE underwent VATS on the day of localization and all GGNs were successfully removed under the guidance of markers.

CONCLUSION

The incidence of AE related to CT-guided localization of GGNs was 0.5%, which was significantly higher than expected. Post-localization whole thoracic CT should be performed and observed carefully so as to avoid missed AE and delayed treatment.

ADVANCES IN KNOWLEDGE

The incidence of AE related to CT-guided localization of GGNs was 0.5%. In order to timely detect AE, whole thoracic CT scan rather than local CT in the lesion area should be performed after localization. A small amount of AE may be missed if the post- localization CT images are not carefully observed.

Case report: Cerebral artery air embolism during CT-guided lung nodule resection in hybrid theater

A middle-aged male received CT-guided lung nodule localization and segmentectomy for a 10-mm lesion in the right upper lung. He developed left side paralysis after surgery, which was proved to be cerebral artery air embolism caused by a CT-guided lung puncture. He achieved almost full recovery with hyperbaric oxygen therapy and intensive rehabilitation. This case highlights the possibility of cerebral artery air embolism during CT-guided lung nodule resection in hybrid theater, with emphasis on prevention and early detection of this life-threatening complication.

Novel Intraoperative CT-Guided Marking Using O-arm System in Video-Assisted Thoracoscopic Surgery: An Easy, Safe, Time-Saving, Practical Method

OBJECTIVE

With the increased frequency of small lung tumor detection, there has been a similar increase in limited surgery, such as wedge resection. To identify such small lung tumors, we use a computed tomography (CT)-guided intraoperative marking method using the O-arm Surgical Imaging System. We retrospectively investigated its usefulness.

METHODS

Of 1,043 cases of thoracic surgery performed at our department between May 2017 and June 2021, O-arm System marking was used in 30 cases (2.9%), totaling 39 lesions. Tumor location was predicted preoperatively based on 3-dimensional CT and anatomic positioning. Visceral pleura near the tumor was marked with a metal clip, and the O-arm System was brought to the surgical site. CT was taken after the tumor side lung was fully re-expanded and clamped. After confirming the tumor and the clip locations, the clip was repositioned as necessary and marked in the same way. If the marking was successful, the clips were used as markers when performing lung resection.

RESULTS

Marking was successful in all cases. The average number of targets was 1.3, the average number of O-arm insertions was 1.3, and the average total number of marking clips was 2.6. In all cases, we checked the specimens, and if the tumor was palpable, the resection margin was also checked. No intraoperative or postoperative complications were observed in any patients.

CONCLUSIONS

If the O-arm System is available, this technique is a noninvasive, simple, and useful method that could be widely used in clinical practice with a low dose of radiation.

Asymptomatic air collection in the left atrium after computed tomography-guided lung biopsy

Systemic air embolism is a fatal lung biopsy complication, despite its low incidence. Incidental air immigration into the pulmonary vein passing through the left heart circulation results in air embolism in percutaneous lung biopsy. Herein, we report a 73-year-old man who presented with massive air collection in the left atrium after computed tomography-guided lung biopsy which resolved without any symptom. Computed tomography fluoroscopy confirmed the gradual absorption process.

Pathological Examination and Differential Diagnosis of Pulmonary Ground-Glass Opacities by CT-Guided Percutaneous Needle Biopsy

In order to explore the pathological examination and differential diagnosis of pulmonary ground-glass opacities (GGO) with CT-guided percutaneous needle biopsy (CTPNB), this study retrospectively analyzed the medical records of 120 cases of patients who were diagnosed with pulmonary GGO and underwent CTPNB in a hospital designated by this study from December 2014 to December 2018. The results showed that all the 120 cases of patients were successfully punctured at one time and obtained sufficient tissue specimens with the puncture success rate and diagnostic accuracy both of 100%, being able to make a clear qualitative diagnosis. Among them, 30 cases were malignant lesions including 14 cases of bronchioloalveolar carcinoma and 16 cases of metastatic carcinoma; 90 cases were benign lesions including 52 cases of hematogenous pulmonary tuberculosis, 14 cases of sarcoidosis, 12 cases of silicosis and coal workers’ pneumoconiosis, 6 cases of interstitial pneumonia, 4 cases of alveolar proteinosis, and 2 case of allergic pneumonia. The complications of the 120 patients during the treatment included 8 cases of pneumothorax with an incidence of 6.67% (8/120), in which 2 case had the pulmonary tissue compression rate of about 25% and the other cases had no obvious perceived symptoms and required no special treatment, and 10 cases of hemoptysis with an incidence of 8.33% (10/120), whose symptoms disappeared after the treatment with batroxobin, and had no serious symptoms such as air embolism complication. The sensitivity, specificity, and accuracy of CTPNB in the diagnosis of malignant pulmonary GGO were 83.67% (82/98), 100% (22/22), and 86.67% (104/120), respectively, without statistically significant differences in diagnostic efficacy (P > 0.05). In summary, the CTPNB for the diagnosis of malignant pulmonary GGO has high sensitivity, specificity, and accuracy, and the CTPNB is also the simplest and most important approach to obtain effective pathological examinations and differential diagnoses of pulmonary GGO, which has simple operation, high accuracy and few complications, and has high application value for the qualitative diagnosis of pulmonary GGO.

Incidence, risk factors, and prognostic indicators of symptomatic air embolism after percutaneous transthoracic lung biopsy: a systematic review and pooled analysis

Objectives

To determine the incidence, risk factors, and prognostic indicators of symptomatic air embolism after percutaneous transthoracic lung biopsy (PTLB) by conducting a systematic review and pooled analysis.

Methods

We searched the EMBASE and OVID-MEDLINE databases to identify studies that dealt with air embolism after PTLB and had extractable outcomes. The incidence of air embolism was pooled using a random effects model, and the causes of heterogeneity were investigated. To analyze risk factors for symptomatic embolism and unfavorable outcomes, multivariate logistic regression analysis was performed.

Results

The pooled incidence of symptomatic air embolism after PTLB was 0.08% (95% confidence interval [CI], 0.048–0.128%; I² = 45%). In the subgroup analysis and meta-regression, guidance modality and study size were found to explain the heterogeneity. Of the patients with symptomatic air embolism, 32.7% had unfavorable outcomes. The presence of an underlying disease (odds ratio [OR], 5.939; 95% CI, 1.029–34.279; p = 0.046), the use of a ≥ 19-gauge needle (OR, 10.046; 95% CI, 1.103–91.469; p = 0.041), and coronary or intracranial air embolism (OR, 19.871; 95% CI, 2.725–14.925; p = 0.003) were independent risk factors for symptomatic embolism. Unfavorable outcomes were independently associated with the use of aspiration biopsy rather than core biopsy (OR, 3.302; 95% CI, 1.149–9.492; p = 0.027) and location of the air embolism in the coronary arteries or intracranial spaces (OR = 5.173; 95% CI = 1.309–20.447; p = 0.019).

Conclusion

The pooled incidence of symptomatic air embolism after PTLB was 0.08%, and one-third of cases had sequelae or died. Identifying whether coronary or intracranial emboli exist is crucial in suspected cases of air embolism after PTLB.

Key Points

• The pooled incidence of symptomatic air embolism after percutaneous transthoracic lung biopsy was 0.08%, and one-third of patients with symptomatic air embolism had sequelae or died.

• The risk factors for symptomatic air embolism were the presence of an underlying disease, the use of a ≥ 19-gauge needle, and coronary or intracranial air embolism.

• Sequelae and death in patients with symptomatic air embolism were associated with the use of aspiration biopsy and coronary or intracranial locations of the air embolism.

Comparison of radiopaque dye materials for localization of pulmonary nodules before video-assisted thoracic surgery

Background

Although a mixture of pigments and radiopaque materials was reported to be useful material for lung nodule localization, the optimal combination has not been well investigated. The purpose of this study is to evaluate the characteristics of various combinations of pigments and radiopaque materials for localization of pulmonary nodules prior to video-assisted thoracic surgery (VATS).

Methods

We compared stability, viscosity, and visibility of 6 radiopaque dye materials of (I) mixture of indigo carmine and lipiodol; (II) mixture of indigo carmine, lipiodol, and lidocaine gel; (III) mixture of indocyanine green in water solution (w-ICG) and lipiodol; (IV) mixture of w-ICG, lipiodol, and lidocaine gel; (V) ICG in contrast medium solution (cm-ICG); and (VI) mixture of cm-ICG and lidocaine gel. Stability was evaluated by observing changes in the mixtures in the test tube with time visually and radiographically. Viscosities were measured by rotational viscometer. Materials were injected into an expanded pig-lung phantom, and area on CT and visibility on thoracoscopy camera were evaluated.

Results

Separation could be seen 15 min after preparation in (I) and (III), and 1 h after preparation in (II), both visually and radiographically. In (IV), separation could be seen on the photographs but not on the X-ray images from 3 h after preparation. (V) and (VI) showed no changes within the 2-day observation period. The viscosities of the materials were (I) 0.2±0.1, (II) 2.9±0.1, (III) 0.2±0.1, (IV) 2.6±0.1, (V) 0.2±0.1, and (VI) 1.2±0.1 dPa·s. The area on CT showed very strong negative correlation with viscosity (r=−0.97). The injection point of each material was easily detected on thoracoscopy camera.

Conclusions

Radiopaque dye materials appear useful for localizing pulmonary nodules before VATS; their diffusion in the lung parenchyma can be suppressed by using materials of high viscosity.