Objective: Although malposition of a catheter for selective cerebral perfusion can lead to postoperative neurologic complications, the clinical relevance or even an incidence of this event is not clear because there have been no measures to diagnose it. The purpose of this study is to report the results of intraoperative diagnosis of catheter malposition by means of near-infrared spectroscopy, orbital ultrasound, and transesophageal echocardiography.
Methods: The 35 consecutive patients of aortic arch aneurysm undergoing total arch replacement (13 patients) or transaortic stent graft implantation (22 patients) were examined. The regional oxygen saturation in the frontal lobe was continuously monitored with near-infrared spectroscopy. When cerebral malperfusion was suspected with saturation drop and reduced blood flow in orbital ultrasound, blood flow in the cervical branches and catheter position were examined with transesophageal echocardiography.
Results: Catheter malposition was detected in 4 of 35 cases (11.4%). The echo findings included: (1) reduced or absent flow and/or collapsed lumen in the common carotid artery despite an adequate perfusion rate; and (2) the balloon of catheter blocking the inflow to the common carotid artery. There was no unusual changes in parameters of other conventional monitors. After the catheter was withdrawn (three cases) or replaced (one case) based on the above diagnosis, cerebral perfusion was restored, confirmed by these three modalities. An accidental entry of catheter into the right common carotid artery was detected by transesophageal echocardiography in one case, in which there was no abnormal finding of oxygen saturation or orbital blood flow.
Conclusions: Catheter malposition on the right side is not a rare event during selective cerebral perfusion. The catheter can migrate into the right subclavian artery or common carotid artery. Pressure monitoring cannot reliably detect an occurrence of catheter migration into the right subclavian artery. Combined use of near-infrared spectroscopy, orbital ultrasound, and transesophageal echocardiography can be useful for detecting this event and making an appropriate decision without delay to prevent irreversible brain damage.