Clinical prospective study of biochemical markers and evoked potentials for identifying adverse neurological outcome after thoracic and thoracoabdominal aortic aneurysm surgery

Background. Neurological deficit after repair of a thoracicor thoracoabdominal aortic aneurysm (TAA/TAAA) remains a devastatingcomplication. The aim of our study was to investigate the clinicalvalue of biochemical markers S-100B, neurone-specific enolase(NSE) and lactate dehydrogenase (LD)], evoked potentials andtheir combinations for identifying adverse neurological outcomeafter TAA/TAAA surgery. Methods. From 69 patients, cerebrospinal fluid and blood samplesfor biochemical analysis were drawn after the induction of anaesthesia,during the cross-clamp period, 5 min, 2, 4, 6, 8, and 19 h,respectively, after reperfusion. In addition, continuous perioperativerecording of motor-evoked potentials after transcranial electricalstimulation (tcMEP) and somatosensory-evoked potentials wascarried out. Furthermore, neurological examinations were performed. Results. In patients with a defined decrease in lower extremitytcMEP during the cross-clamp period, we found that combinationsof the serum concentrations of S-100B and tcMEP ratios at 4,6, and 8 h after reperfusion had a positive and negative predictivevalue of 100% in predicting adverse neurological outcome afterTAA/TAAA surgery. Furthermore, combinations of the serum concentrationsof S-100B and NSE or LD at 19 h after reperfusion had both apositive and negative predictive value of 100% in identifyingpatients with adverse outcome after TAA/TAAA repair. Conclusions. TcMEP monitoring during TAA/TAAA surgery seemsto be an effective but not completely sufficient guide in ourprotective multi-modality strategy. Combinations of the serumconcentrations of S-100B and tcMEP ratios during the early reperfusionperiod might be associated with adverse neurological complications.Furthermore, biochemical markers could detect central nervoussystem injury on the first postoperative day and may have prognosticvalue.