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OBJECTIVE Impact of the decrease of regional cerebral oxygen saturation (rSO2) on postoperative delayed awakening after total aortic arch replacement (TAR) was validated. METHODS From 2008 to 2013, 143 consecutive patients underwent TAR using selective antegrade cerebral perfusion. rSO2 was monitored using near-infrared spectroscopy. We calculated a percent decrease of rSO2 (%-D) immediately after rewarming according to the following formula: %-D = rSO2 (X1) − rSO2 (X2)/rSO2 (X1) × 100 (%), where rSO2 (X1) was measured at the beginning of rewarming, and rSO2 (X2) was measured 10 min later. Delayed awakening was defined as patients not waking up for more than 6 h after the termination of anaesthesia. RESULTS The average time to wake up was 3.6 ± 2.0 h. Fourteen patients showed delayed awakening. %-D showed a positive linear relationship to awakening time (y = 0.67x − 0.7, r = 0.23, P = 0.007) and receiver operating characteristic analysis showed %-D had a good predictive value for delayed awakening (area under the curve = 0.84). %-D was significantly different between the delayed awakening and the normal group (7.1 ± 5.1 vs 1.3 ± 6.6%, P = 0.002). Two patients (1.4%) who had multicomorbidity with higher %-D died in the hospital due to colon necrosis and sepsis. There were significant differences between patients with normal and delayed awakening in hospital mortality (P = 0.04) and transient neurological deficit (TND, P = 0.007). CONCLUSION The maintenance of rSO2 at the early phase of rewarming may be important to avoid delayed awakening or TND after TAR. [ABSTRACT FROM PUBLISHER]

Abstract: 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. [Copyright &y& Elsevier]

Objective: To minimize the neurological complications following cardiovascular surgery, it is essential to prevent an occurrence of cerebrovascular embolism and to detect and solve cerebral malperfusion without delay in the operating theater. Although we have introduced near-infrared spectroscopy (NIRS) monitoring for the purpose of detecting cerebral malperfusion, no criterion has been available. We searched for this criterion by examining the relationship of sustained drop in the regional oxygen saturation (rSO2) of the frontal lobes to the occurrence of neurological events. Methods: The 59 consecutive patients undergoing aortic surgery with selective cerebral perfusion (SCP) were examined. The rSO2 was monitored throughout the surgery and the durations of drops in rSO2 to below 55% and those below 60% were determined for each patient. The durations of rSO2 drop and other surgery-related parameters were compared between the patients in whom neurological events occurred and those without such events. Results: A total of 16 cases (27.1%) presented with neurological events. Newly developed cerebral infarction was documented in 6 of these 16 cases. Operation time and the durations for which rSO2 dropped were significantly longer for the 16 patients with neurological events than for the 43 patients without events (Op time: 546.8 versus 448.1min, P=0.0064; rSO2 below 60%: 141.2 versus 49.8min, P=0.0032; rSO2 below 55%: 66.6 versus 10.6min, P=0.0011), while there was no significant difference in age, bypass time, aortic clamping time, SCP time, and circulatory arrest time between the two groups. In the 3 patients with infarcts suggestive to hypoperfusion, sustained decrease in rSO2 was observed, while it was not significant in the remaining 3 patients with infarcts suggestive to embolism. Among the 53 patients without infarction, transient neurological events occurred more frequently in patients with sustained drop in rSO2 below 55% for over 5min (44.4% versus 5.7%, P=0.0014). Conclusions: A sustained drop in rSO2 during aortic surgery is closely related to the occurrence of neurological events following surgery. We recommend that recovery of drop in rSO2 below 55% should be addressed without delay. However, use of NIRS is limited for detecting embolic events or hypoperfusion in the basilar region. [Copyright &y& Elsevier]