We present the case of a 72-year-old man with cardiac adenocarcinoma treated with
a metal stent and radiation therapy for pulmonary metastases. After 6 months of this
treatment he developed a malignant esophageal stricture. Endoscopy was carried out
under moderate sedation and constant monitoring. Dilation with an over-the-scope balloon
dilator (CRE single-use, wire-guided esophageal dilation balloon, 240 cm, balloon
length 5.5 cm, outer diameter 10 – 12 mm, Boston Scientific, Natick, Massachusetts,
USA) was carried out. The patient’s vital signs and oxygen saturation were normal
throughout the procedure. However, when flumazenil was administered the patient did
not recover. Neurological examination revealed a Glasgow Coma Scale score of 4/15
points, pupils equal and reactive to light, and no focal neurological signs. Cardiac
and respiratory functions were stable. Brain computed tomography (CT) revealed bilateral
multifocal cerebral air embolism with air bubbles within the sagittal sinus, straight
sinus, great vein of Galen, and the cerebral venous network of the cortex ([Fig. 1]), and 24 hours later the patient died.
Fig. 1 a, b Computed tomography (CT) scans in a 72-year-old man who underwent endoscopy for an
esophageal stricture 6 months after being treated for cardiac adenocarcinoma with
a metal stent and radiation therapy for pulmonary metastases. The scans show bilateral
multifocal cerebral air embolism with air bubbles within the sagittal sinus, straight
sinus, great vein of Galen, and the cerebral venous network of the cortex.
The entry of air into the vascular system during endoscopy is a serious complication
and is usually accompanied by interruption of the mucosal barrier [1]
[2]
[3]. Our patient developed pneumocephalus as a result of gas entry either directly into
the arterial system or indirectly through the venous system. Paradoxical embolism
via an intracardiac shunt [4] or pulmonary shunts due to metastases cannot be excluded, although hemodynamic instability
was not observed. The esophagus is directly in contact with the posterior wall of
the left atrium between the mid-posterior part of the atrium and the distal border
of the inferior pulmonary veins [5]. Arterial gas entry may have occurred under positive air pressure due to proximity
of malignant and radiation trauma. Cerebral air embolism during an endoscopic intervention
has not been reported previously, but it should be suspected in case neurological
deterioration ensues as the prognosis is poor.
Endoscopy_UCTN_Code_CPL_1AH_2AF
