Prevention of spinal cord ischemia in surgery of choraco-abdominal aneurysms *1The Bio Medicus pump, the recording of somatosensory evoked potentials and the impact on surgical strategy

Abstract
Over a 15-month period 14 consecutive patients underwent surgery forextensive thoracoabdominal aneurysms with a nonheparinized centrifugallypumped (Bio Medicus) bypass and somatosensory evoked potential (SEP)recording. Six patients had a femorofemoral and eight patients a leftatrial-common femoral artery bypass. The study aimed to assess thecontribution of this approach to the prevention of spinal cord ischemia andthe impact of the approach on surgical strategy. All patients survivedoperation; the 30-day and hospital mortality was 21% (three patients). Twopatients became paraplegic. No major cardiac and renal complicationsoccurred. Distal aortic perfusion allowed staged cross-clamping of theaorta in five (35.7%) patients, resulting in a significant reduction inmean spinal cross-clamp time: 23.4 min versus a calculated time of 47.2 minin the same patients if distal aortic perfusion had not been used (p lessthan or equal to 0.002). In one patient surgical strategy was adjustedduring cross-clamping in order to reattach a critical intercostal artery.SEP-derived information confirmed the appropriateness of the surgicalstrategy in all cases. Whether the spinal cord was protected by thisperfusion remained unproven. No bypass-related complications occurred.Distal aortic perfusion and concomitant SEP monitoring offer an improvementof surgical strategy and safer surgery.