Selective Use of Left Heart Bypass for Aortic Coarctation. Discussion

Background. We evaluated left heart bypass (LHB) for spinal cord protection during aortic coarctation repair in patients with mild (primary, postsurgical, or intervention) and complex coarctation. Methods. Between 1990 and 2008, 19 patients (mean age, 21 years; weight, 70 ± 16 kg) using LHB were compared with 27 patients (mean age, 16 years; weight, 65 ± 8 kg) undergoing coarctation repair without LHB (non-LHB). Follow-up was similar (LHB, 5 ± 4 vs non-LHB 4 ± 3 years; p = 0.81). Results. Cohorts were similar in age and body surface area. No non-LHB patient lost somatosensory evoked potential or had a femoral artery pressure below 45 mm Hg with test clamping. LHB more often allowed graft interposition (18 of 19 [95%] vs non-LHB, 7 of 27 [26%]; p < 0.003) and a longer clamp time (LHB 44 ± 16 vs non-LHB 31 ± 12 minutes p < 0.003) without spinal cord ischemia. Two non-LHB patients had temporary spinal cord paresis. No early or late deaths occurred. Reintervention (LHB, 2 of 19 [11%] vs non-LHB, 2 of 27 [7%]; p = 0.82) and antihypertensive requirements were similar (LHB, 9 of 19 [40%] vs non-LHB, 8 of 27 [30%]; p = 0.35). The late peak transcoarctation gradient was 8 ± 6 mm Hg in the LBH cohort vs 18 ± 11 mm Hg in non-LBH patients (p= 0.001). Conclusions. Although the adequacy of spinal cord collateral assessment in coarctation repair is imperfect, no spinal cord ischemia occurred with coarctation repair and LHB. We recommend LHB in patients with mild or complex coarctation.