Air Embolism During Core Needle Biopsy of the Lung
For 23 patients, 8 women and 15 men with a mean age of 56.5 ± 18.1 years, an SAE was verified during or after the biopsy. This is equivalent to 3.8% of all patients. No SAE was detected in 587 patients, 244 women and 343 men with a mean age of 63.7 ± 13.4 years, corresponding to 96.2% of all patients.
Hemorrhage was verified by CT scan in 400 patients (65.6%). Of these, 397 cases (99.3%) required no therapy (minor complication A), and 3 required nominal therapy consisting of bronchoscopic suctioning (minor complication B). In one patient, the bleeding had to be treated by microcoil embolization of the intercostal artery. Her hospital stay was extended by more than 48 hours (major complication D).
Pneumothorax developed in 94 patients (15.4%); ten patients (1.6%) had to be treated with a chest tube and 84 patients (89.6%) were observed only. This was classified as minor complication A for 83 patients, as minor complication B for one patient requiring nominal therapy, and major complication D for 10 patients requiring prolonged hospitalization > 48 hours.
While no symptoms occurred in 20 of the 23 patients with SAE, three patients showed symptoms. One male patient developed a transient bilateral amaurosis (major complication D, prolonged hospitalization > 48 hours), one male patient had transient hemiplegia that regressed completely (major complication D, prolonged hospitalization > 48 hours), and one female patient suffered a fatal coronary infarction from an SAE (major complication F, death; Figure 1). The mortality from SAE was thus 1/610 (0.16%), morbidity was 2/610 (0.3%).
(Enlarge Image)
Figure 1.
a and b: Transversal CT-slice, showing SAE in the coronary arteries, the aorta, the left atrium and ventricle (a). The lesion was located in the left upper lobe (b), at the time of biopsy approximately 8 cm above the level of the left atrium. 49 y/o patient after lung transplantation, suffering from pulmonary aspergillosis. She died due to coronary ischemia.
In four patients, the embolism was detected during or directly after the examination on the basis of the CT scans; in two patients, shortly afterward due to the symptoms of amaurosis and cerebral infarction. The other 17 cases were detected retrospectively when evaluating the images in the PACS for this study. Other examples of SAE's are shown in Figure 2 and 3.
(Enlarge Image)
Figure 2.
a and b: Transversal CT-slice of a 29 y/o patient during the biopsy of a tumor located in the right hilum of the lung (a). The CT-Scan after biopsy showed a SAE in the apex of the left ventricle (b), which was treated immediately. There were no clinical sequelae.
(Enlarge Image)
Figure 3.
a and b: Transversal CT-slice of a 48 y/o patient during the biopsy of a small nodule located in the left lower lobe (a). The CT-Scan after biopsy showed a SAE in the left atrium, the aorta, and intercostal arteries (b). The patient suffered from a transient amaurosis.
In the univariate analyses of categorical variables, prone position of the patient, and location of the lesion in the lower lobe were risk factors for an SAE (p < 0.05 each, Table 1). There was also a tendency seen for the factor endotracheal anesthesia (p < 0.1, Table 1). In the univariate analyses of continuous variables, caudal position of the lesion, level of the lesion above that of the left atrium respective to the patient's position, large number of biopsies, and small CT-slice thickness during the biopsy, were risk factors for an SAE (p < 0.05 each, Table 2). An intravascular position of the tip of the needle was never observed.
The independent risk factors for the occurrence of an SAE, determined using standard selection criteria in the order of significance, are shown in Table 3. If less restrictive selection criteria were used for including a variable in the model (probability for stepwise entry 0.1 and removal 0.2), the factors needle path through ventilated lung and acute angle of the needle to the surface of the tumor also occur in the models (Table 4)
Results
Assigning Patients to the Two Groups
For 23 patients, 8 women and 15 men with a mean age of 56.5 ± 18.1 years, an SAE was verified during or after the biopsy. This is equivalent to 3.8% of all patients. No SAE was detected in 587 patients, 244 women and 343 men with a mean age of 63.7 ± 13.4 years, corresponding to 96.2% of all patients.
Complications
Hemorrhage was verified by CT scan in 400 patients (65.6%). Of these, 397 cases (99.3%) required no therapy (minor complication A), and 3 required nominal therapy consisting of bronchoscopic suctioning (minor complication B). In one patient, the bleeding had to be treated by microcoil embolization of the intercostal artery. Her hospital stay was extended by more than 48 hours (major complication D).
Pneumothorax developed in 94 patients (15.4%); ten patients (1.6%) had to be treated with a chest tube and 84 patients (89.6%) were observed only. This was classified as minor complication A for 83 patients, as minor complication B for one patient requiring nominal therapy, and major complication D for 10 patients requiring prolonged hospitalization > 48 hours.
Complications Due to Intravascular Air
While no symptoms occurred in 20 of the 23 patients with SAE, three patients showed symptoms. One male patient developed a transient bilateral amaurosis (major complication D, prolonged hospitalization > 48 hours), one male patient had transient hemiplegia that regressed completely (major complication D, prolonged hospitalization > 48 hours), and one female patient suffered a fatal coronary infarction from an SAE (major complication F, death; Figure 1). The mortality from SAE was thus 1/610 (0.16%), morbidity was 2/610 (0.3%).
(Enlarge Image)
Figure 1.
a and b: Transversal CT-slice, showing SAE in the coronary arteries, the aorta, the left atrium and ventricle (a). The lesion was located in the left upper lobe (b), at the time of biopsy approximately 8 cm above the level of the left atrium. 49 y/o patient after lung transplantation, suffering from pulmonary aspergillosis. She died due to coronary ischemia.
Detection of Intravascular Air
In four patients, the embolism was detected during or directly after the examination on the basis of the CT scans; in two patients, shortly afterward due to the symptoms of amaurosis and cerebral infarction. The other 17 cases were detected retrospectively when evaluating the images in the PACS for this study. Other examples of SAE's are shown in Figure 2 and 3.
(Enlarge Image)
Figure 2.
a and b: Transversal CT-slice of a 29 y/o patient during the biopsy of a tumor located in the right hilum of the lung (a). The CT-Scan after biopsy showed a SAE in the apex of the left ventricle (b), which was treated immediately. There were no clinical sequelae.
(Enlarge Image)
Figure 3.
a and b: Transversal CT-slice of a 48 y/o patient during the biopsy of a small nodule located in the left lower lobe (a). The CT-Scan after biopsy showed a SAE in the left atrium, the aorta, and intercostal arteries (b). The patient suffered from a transient amaurosis.
Univariate Analysis of the Risk Factors
In the univariate analyses of categorical variables, prone position of the patient, and location of the lesion in the lower lobe were risk factors for an SAE (p < 0.05 each, Table 1). There was also a tendency seen for the factor endotracheal anesthesia (p < 0.1, Table 1). In the univariate analyses of continuous variables, caudal position of the lesion, level of the lesion above that of the left atrium respective to the patient's position, large number of biopsies, and small CT-slice thickness during the biopsy, were risk factors for an SAE (p < 0.05 each, Table 2). An intravascular position of the tip of the needle was never observed.
Multivariate Analysis of the Risk Factors
The independent risk factors for the occurrence of an SAE, determined using standard selection criteria in the order of significance, are shown in Table 3. If less restrictive selection criteria were used for including a variable in the model (probability for stepwise entry 0.1 and removal 0.2), the factors needle path through ventilated lung and acute angle of the needle to the surface of the tumor also occur in the models (Table 4)
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