Table 1.
Summary of demographic and pre- and post-operative cerebral hemodynamic variables measured for subjects with and without new or worsened PVL > 76.3 mm3, presented by means ± standard deviation for continuous variables and frequencies (%) for categorical variables.
| Variable | All (n=37) | PVL (n=18) | No PVL (n=19) | P |
|---|---|---|---|---|
| Time-to-surgery, days | 4.2±1.9 | 5.3±1.5 | 3.1±1.7 | <0.001* |
| Time between MRI, days | 7.1±2.8 | 7.1±2.9 | 7.0±2.9 | 0.90 |
| Gestational age, wk | 38.8±0.8 | 38.9±0.9 | 38.8±0.7 | 0.59 |
| Birth weight, kg | 3.3±0.5 | 3.3±0.5 | 3.2±0.5 | 0.77 |
| Head circumference, cm | 34.0±1.4 | 34.1±1.5 | 34.0±1.3 | 0.55 |
| Female, n (%) | 19 (51.4) | 10 (55.6) | 9 (47.4) | 0.64 |
| Aortic Stenosis, n (%) | 9 (27.3) | 5 (31.3) | 4 (23.5) | 0.64 |
| Blalock-Taussig shunt, n (%) | 28 (75.7) | 13 (72.2) | 15 (79.0) | 0.65 |
| Intact atrial septum, n (%) | 4 (10.8) | 1 (5.6) | 3 (15.8) | 0.34 |
| TMS | 9.9±0.9 | 10.1±0.9 | 9.8±1.0 | 0.34 |
| Pre-operative SaO2, % | 90.0±5.2 | 90.1±4.0 | 89.9±6.1 | 0.57 |
| Pre-operative cerebral hemodynamics | ||||
| ScO2, % | 48.8±13.3 | 44.3±13.4 | 54.3±11.3 | 0.09# |
| BFI, 10−8 cm2/s | 2.4±1.6 | 3.0±1.9 | 1.9±1.1 | 0.05# |
| CBV, mL/100g | 2.1±0.5 | 2.1±0.6 | 2.1±0.4 | 0.52 |
| OEF | 0.61±0.20 | 0.68±0.22 | 0.54±0.16 | 0.15 |
| CMRO2,I, 10−7 ml/dl × cm2/s | 1.7±1.4 | 2.1±1.9 | 1.4±0.6 | 0.26 |
| Operative variables | ||||
| CPB time, | 92.2±25.3 | 96.8±33.0 | 87.7±14.5 | 0.70 |
| DHCA time, min | 44.8±9.7 | 46.4±12.0 | 43.3±6.7 | 0.74 |
| Lowest NP temperature, | 17.8±0.9 | 17.9±1.0 | 17.6±0.8 | 0.20 |
| Number of bypass runs, n | 1.1±0.4 | 1.2±0.5 | 1.0±0 | 0.14 |
| Delayed sternal closure, n (%) | 5 (13.5) | 4 (22.2) | 1 (5.3) | 0.14 |
| Cardiac arrest prior to post-operative MRI, n (%) | 2 (5.4) | 2 (11.1) | 0 (0) | 0.15 |
| Post-operative cerebral hemodynamics | ||||
| Initial ScO2, % | 40.8±7.2 | 41.3±7.6 | 40.4±7.1 | 0.57 |
| Initial BFI, 10−8 cm2/s | 1.5±0.7 | 1.6±0.9 | 1.3±0.3 | 0.35 |
| Initial CBV, mL/100g | 3.9±0.7 | 3.9±0.7 | 3.8±0.8 | 0.83 |
| Initial OEF | 0.58±0.15 | 0.57±0.14 | 0.59±0.16 | 0.85 |
| Initial CMRO2,i, 10−7 ml/dl × cm2/s | 1.9±1.8 | 2.0±1.4 | 1.7±2.2 | 0.24 |
| Lowest ScO2, % | 35.0±9.4 | 34.2±10.5 | 35.9±8.3 | 0.65 |
| Change from pre- to post-operative | ||||
| ScO2,post-operative- ScO2,pre-operative, % | −8.0 (13.1) | −3.9 (12.5) | −12.4 (12.8) | 0.10 |
| BFIpost-operative/BFIpre-operative, (%) | 1.1 (0.5) | 1.1 (0.6) | 1.0 (0.4) | 0.68 |
A Wilcoxon rank-sum test used to test differences between the two groups. (* significant, # marginally significant). TMS, Total Maturation Score; SaO2, arterial oxygen saturation; ScO2, cerebral tissue oxygen saturation; BFI, Blood Flow Index; CBV, Cerebral Blood Volume; CMRO2,i, Index of Cerebral Metabolic Rate of Oxygen; CPB, Cardiopulmonary Bypass; DHCA, Deep Hypothermic Circulatory Arrest; NP, Nasopharyngeal.