An unusual cerebral air embolism developing within the posterior circulation territory after a needle lung biopsy

Systemic arterial gas embolism (SAGE) as a complication of bronchoscopic lung biopsy: a case report and systematic literature review

Background

Systemic arterial gas embolism (SAGE) is a rare yet serious and underrecognized complication of bronchoscopic procedures. A recent case of presumed SAGE after transbronchial needle aspiration prompted a systematic literature review of SAGE after biopsy procedures during flexible bronchoscopy.

Methods

We performed a systematic database search for case reports and case series pertaining to SAGE after bronchoscopic lung biopsy; reports or series involving only bronchoscopic laser therapy or argon plasma coagulation (APC) were excluded. Patient data were extracted directly from published reports.

Results

A total of 29 unique patient reports were assessed for patient demographics, specifics of the procedure, clinical manifestations, diagnostic findings, and clinical outcomes. Cases of SAGE occurred after multiple types of bronchoscopic biopsy and under both positive and negative pressure ventilation. The most common clinical findings were neurologic, followed by cardiac manifestations; temporal patterns included acute onset of cardiac or neurologic emergencies immediately after biopsy, or delayed awakening post-procedure. There was a high mortality rate among cases (28%), with residual neurologic deficits also common (24%).

Discussion

SAGE is an underrecognized but severe adverse effect of bronchoscopic lung biopsy, which often presents with acute coronary or cerebral ischemia or delayed awakening from sedation. It is important for all physicians who perform bronchoscopic biopsies to be aware of the clinical manifestations and therapeutic management of SAGE in order to mitigate morbidity and mortality among patients undergoing these procedures.

Postoperative cerebral air embolism with delayed abnormal brain MRI findings

Cerebral air embolism (CAE) is a rare but well-known complication resulting from invasive medical procedures; however, previous studies have not examined the postoperative longitudinal MRI changes in CAE. In particular, the likelihood that such changes may be observed after an initial delay when using magnetic resonance imaging (MRI) has not been explored. We herein report a case of CAE with no MRI abnormalities 4 h after a pulmonary vein isolation (PVI) procedure and where the first abnormality was found 22 h after the procedure. A 65-year-old man underwent PVI for paroxysmal atrial fibrillation and showed no signs of recovery from anesthesia after the procedure; thus, he was transferred to our emergency department for further examination. Neurological examination revealed conjugate eye deviation to the right and quadriplegia. Although initial computed tomography (CT) and MRI revealed no abnormalities, CAE was suspected, and a high-concentration oxygen treatment was administered. MRI performed 22 h after the procedure revealed restricted diffusion affecting the cortical areas. At the same day, he was transferred for hyperbaric‑oxygen chamber treatment. After 7 days of treatment, the patient recovered clinically and neurologically. He regained consciousness and was able to communicate. As suggested by this case, CT and MRI findings may fail to reveal CAE abnormalities initially. In such cases, as urgent treatment is necessary, it is important to consider diagnosing CAE based on the patient's history and administering a high concentration of oxygen. Finally, to reach a correct diagnosis, repeated brain MRI should be considered for patients with suspected CAE.

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.

[Cerebral air embolism: A rare complication of flexible fiberoptic bronchoscopy]

INTRODUCTION

Cerebral air embolism is a rare complication of flexible fiberoptic bronchoscopy. It is a serious, life-threatening complication. The treatment consists of hyperbaric oxygen therapy.

CASE REPORT

We report the case of cerebral air embolism that occurred in an 80-year-old woman after a flexible bronchial fibroscopy with bronchial spur biopsies. The patient showed neurological signs after the procedure. The brain CT-scan found disseminated air emboli. The progress was fatal in the absence of specific treatment, taking account of the context, the patient's comorbidities and the wishes of the family.

CONCLUSIONS

Cerebral air embolism is a serious complication that can occur during a bronchial biopsy even though this complication is rare.

Changes over Time in Intracranial Air in Patients with Cerebral Air Embolism: Radiological Study in Two Cases

Cerebral air embolism can be easily identified on computed tomography (CT) scans. However, changes in the distribution and amount of intracranial air are not well known. We report two patients with cerebral air embolism and present imaging findings on the serial changes in the intracranial air. We thought that the embolic source was venous in one patient because CT showed air inflow in cortical veins in the bilateral frontal areas, reflecting air buoyancy. In the other patient, CT showed air inflow into not only the cortical veins but also the bilateral cerebral hemispheres and we thought this to be a paradoxical cerebral air embolism. We found that intracranial air can be promptly absorbed and while cerebral infarcts due to air are clearly visualized on diffusion-weighted images (DWI), the air may rapidly disappear from images. In patients with suspected cerebral air embolism whose CT findings show no intracranial air, DWI should be performed because it may reveal cerebral infarction due to cerebral air embolism.

Unusual Cerebral Emboli

The heart and the carotid arteries are the most common sites of origin of embolic disease to the brain. Clots arising from these locations are the most common types of brain emboli. Less common cerebral emboli include air, fat, calcium, infected vegetations, and tumor cells as well as emboli originating in the venous system. Although infarcts can be the final result of any type of embolism, described herein are the ancillary and sometimes unique imaging features of less common types of cerebral emboli that may allow for a specific diagnosis to be made or at least suspected in many patients.

Influenceable and Avoidable Risk Factors for Systemic Air Embolism due to Percutaneous CT-Guided Lung Biopsy: Patient Positioning and Coaxial Biopsy Technique-Case Report, Systematic Literature Review, and a Technical Note

Following the first case of a systemic air embolism due to percutaneous CT-guided lung biopsy in our clinic we analysed the literature regarding this matter in view of influenceable or avoidable risk factors. A systematic review of literature reporting cases of systemic air embolism due to CT-guided lung biopsy was performed to find out whether prone positioning might be a risk factor regarding this issue. In addition, a technical note concerning coaxial biopsy practice is presented. Prone position seems to have relevance for the development and/or clinical manifestation of air embolism due to CT-guided lung biopsy and should be considered a risk factor, at least as far as lesions in the lower parts of the lung are concerned. Biopsies of small or cavitary lesions in coaxial technique should be performed using a hemostatic valve.