DOI:10.2214/AJR.06.0179
AJR 2006; 187:W327-W328
© American Roentgen Ray Society
Nonfatal Systemic Air Embolism During Percutaneous Radiofrequency Ablation of a Pulmonary Metastasis
Benoit Ghaye,
Pierre-Julien Bruyère and
Robert F. Dondelinger
University Hospital of Liege Liege B-4000, Belgium
WEB—This is a Web exclusive article.
A 73-year-old nonsmoking woman was referred for percutaneous radiofrequency
ablation of a pulmonary metastasis. Hysterectomy had been performed for
uterine leiomyosarcoma 6 years earlier, followed by adjuvant brachytherapy and
chemotherapy. Right lower lobectomy and two wedge-resections in the right
upper lobe and lingula were performed for four metastases during the next 4
years. Now percutaneous radiofrequency ablation was requested for treatment of
an 11-mm metastasis that appeared in the left upper lobe 1 year after the last
lung surgery.
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Fig. 1A —73-year-old woman with systemic air embolism. 5-mm-thick
maximum-intensity-projection reformation from CT centered on left lung before
radiofrequency needle insertion shows subpleural nodule in left upper lobe in
close contact with venous structure anteriorly (arrowhead). Image was
obtained with patient in right lateral decubitus position. No diseased lung or
emphysema is shown.
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Fig. 1B —73-year-old woman with systemic air embolism. 5-mm-thick
maximum-intensity-projection reformation after radiofrequency needle insertion
shows air inside vein (arrowhead) and in descending aorta (black
arrow). Note moderate hemorrhage along needle path (white
arrow).
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Fig. 1C —73-year-old woman with systemic air embolism. Full-view axial
CT reconstruction after radiofrequency needle insertion shows massive air
collection inside left atrium, left ventricle, and in descending aorta
(arrows). Image was obtained with patient in right lateral decubitus
position.
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Fig. 1D —73-year-old woman with systemic air embolism. Axial CT
reconstruction after radiofrequency needle insertion shows blood-air level in
aortic arch (arrow). Image was obtained with patient in right lateral
decubitus position.
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Using CT fluoroscopic guidance, and with the patient under general
anesthesia and in the right lateral decubitus position, an 18-gauge LeVeen
Needle Electrode (Boston Scientific) was introduced through the seventh
intercostal space without patient breath-holding. The resistance of the nodule
required four puncture attempts before the cluster tip was deployed inside the
lesion. Helical imaging was performed, and 3D reformatting confirmed optimal
needle deployment inside the nodule before treatment.
Before radiofrequency application, zooming in on the nodule showed air in a
pulmonary vein close to the nodule. The full volume-of-interest reconstruction
showed an extensive air-blood level inside the left inferior pulmonary vein,
left atrium and ventricle, and aortic arch (Fig. 5). Although the patient
remained stable, the needle was immediately retrieved and, under the
precautionary measure of compressing both carotid arteries, the patient was
turned prone in a Trendelenburg position to avoid cephalic air embolism.
The patient was treated with 100% oxygen, antiplatelet agents, and
vasodilators. Immediate hyperbaric oxygen treatment was not available.
Thoracic CT 20 minutes later showed complete disappearance of air inside the
heart chambers and vessels. Cranial CT was unremarkable. The patient was
transferred to the ICU for observation and was discharged 2 days later.
Clinical examination, blood tests, ECG, and EEG were unremarkable except for a
known hemiparesis of the right hand resulting from a cerebral vascular attack
2 years previously.
Percutaneous radiofrequency ablation has recently been applied as a
therapeutic technique for focal malignant disease in the thorax
[1,
2]. Reported complications of
thoracic radiofrequency ablation are generally minor and occur at a rate
similar to or slightly higher than the rate of complications in percutaneous
transthoracic needle biopsy
[2].
Systemic air embolism is a rare but potentially fatal complication
(incidence, 0.01-0.16%) after percutaneous transthoracic needle biopsy
[3]. About 20 cases of systemic
air embolism after percutaneous transthoracic needle biopsy have been reported
in the English-language literature.
Treatment of systemic air embolism usually includes oxygen therapy,
infusion therapy, steroids, antiplatelet drugs, anticonvulsant and vasoactive
agents, and, most important, hyperbaric oxygen chamber therapy
[3,
4]. Placing the patient in a
supine, Trendelenburg, or left lateral decubitus position remains
controversial when the location of an intraluminal air collection is not
documented [3,
4]. To our knowledge, this is
the first case of systemic air embolism resulting from percutaneous thoracic
radiofrequency ablation.
Factors that might have increased the risk of creating a fistula between
airspaces or small airways and pulmonary veins in our patient may include
strong cellular cohesion of a sarcomatous metastasis rendering nodule puncture
difficult by a 16- or 18-gauge radiofrequency ablation needle, history of
multiple lung resections resulting in lung overdistention, and endotracheal
tube ventilation causing transient positive-pressure ventilation
[2,
3].
Such a complication and its management must be recognized by radiologists
who perform thoracic radiofrequency ablation.
References
- Steinke K, Sewell PE, Dupuy D, et al. Pulmonary radiofrequency
ablation: an international study survey. Anticancer
Res 2004; 24:339
-343[Medline]
- Steinke K, King J, Glenn DW, Morris DL. Percutaneous radiofrequency
ablation of lung tumors with expandable needle electrodes: tips from
preliminary experience. AJR 2004;183
: 605-611[Free Full Text]
- Worth ER, Burton RJ Jr, Landreneau RJ, Eggers GW Jr, Curtis JJ.
Left atrial air embolism during intraoperative needle biopsy of a deep
pulmonary lesion. Anesthesiology 1990;73
: 342-345[Medline]
- Muth CM, Shank ES. Gas embolism. N Engl J
Med 2000; 342:476
-482[Free Full Text]
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