Jan Hinnerk Hansen

Outcome of the Norwood operation in patients with hypoplastic left heart syndrome: a 12-year single-center survey.

OBJECTIVE Recent advances in perioperative care have led to a decrease in mortality of children with hypoplastic left heart syndrome undergoing the Norwood operation. This study aimed to evaluate the outcome of the Norwood operation in a single center over 12 years and to identify clinical and anatomic risk factors for adverse early and longer term outcome. METHODS Full data on all 157 patients treated between 1996 and 2007 were analyzed. RESULTS Thirty-day mortality of the Norwood operation decreased from 21% in the first 3 years to 2.5% in the last 3 years. The estimated exponentially weighted moving average of early mortality after 157 Norwood operations was 2.3%. Risk factors were an aberrant right subclavian artery, the use and duration of circulatory arrest, and the duration of total support time. The anatomic subgroup mitral stenosis/aortic atresia and female gender tended to show an increased early mortality. In the group of patients who required postoperative cardiopulmonary resuscitation, the ascending aorta was significantly smaller than in the remainder (3.03 +/- 1.05 vs 3.63 +/- 1.41 mm). Interstage mortality was 15% until the initiation of a home surveillance program in 2005, which has zeroed it so far. It was significantly higher in the mitral stenosis/aortic atresia subgroup and tended to be higher in patients who required cardiopulmonary resuscitation after the Norwood operation. The best actuarial survival was observed in the mitral atresia/aortic atresia subgroup. CONCLUSION The Norwood operation can now be performed with low mortality. Patients with mitral stenosis/aortic atresia still constitute the most challenging subgroup.

Arterial elastance and its impact on intrinsic right ventricular function in palliated hypoplastic left heart syndrome

BACKGROUND Systemic right ventricular (RV) function is a major determinant of long-term outcome in patients with palliated hypoplastic left heart syndrome (HLHS). Abnormal elastic properties of the reconstructed aorta may negatively impact on ventricular function. We therefore aimed to assess arterial elastance and its relationship to systemic RV function in these patients. METHODS Fifty-six HLHS patients (median age 5.4 years; range 2.9-14.2 years) were studied at a median of 2.6 years (range 0.8-12.7 years) after completion of the Fontan circulation with the pressure-volume conductance system. RESULTS Arterial elastance (Ea) was abnormally high and correlated inversely with RV ejection fraction (r=-0.42, P=0.001). However, end systolic elastance (Ees) - a load independent measure of intrinsic systolic ventricular function - and more so end diastolic stiffness (Eed) were positively correlated with Ea (Ees vs. Ea: r=0.44, P=0.001: Eed vs. Ea: r=0.62, P<0.0001). Patients who were treated for significant aortic arch obstruction after surgical palliation showed higher Ea and Eed even four years after successful treatment compared to the remainder of the group (Ea: 3.4 ± 1.2 vs. 2.8 ± 1.0 mmHg/ml, P=0.04 and Eed: 0.67 ± 0.44 vs. 0.45 ± 0.3 mmHg/ml, P=0.04). CONCLUSIONS Arterial elastance is abnormally high in palliated HLHS patients and negatively impacts on ejection fraction but not on intrinsic systolic RV function early after completion of the Fontan circulation. Increased arterial elastance, however, is associated with increased RV diastolic stiffness with potential adverse effects on long-term outcome. Furthermore, arterial elastance and diastolic stiffness are particularly high in patients who needed treatment for aortic arch obstruction.

Risk factors for adverse outcome after superior cavopulmonary anastomosis for hypoplastic left heart syndrome

OBJECTIVE Outcome of staged palliation for hypoplastic left heart syndrome (HLHS) has improved over the past decades. We sought to evaluate the outcome of the second palliative procedure, the superior cavopulmonary anastomosis (SCPA), in a single-centre cohort and to identify risk factors for adverse outcome. METHODS Full data on all 119 HLHS patients who underwent SCPA in our centre between January 1996 and December 2007 were analysed. RESULTS Early adverse outcome (death or cardiac transplant within 30 days after surgery or before hospital discharge) was 3.4%. Late adverse outcome (death or transplant after hospital discharge but before the next operative procedure) was 8.7%. Postoperative complications occurred in 30% of patients (n = 36), with transient arrhythmia (n = 11; 9%) and pulmonary artery stenosis or thrombosis (n = 10; 8%) being the most common. The presence of more than moderate tricuspid valve regurgitation after surgery proved to be a strong predictor of late adverse outcome (odds ratio (OR) 16.5 (4.4-62.6), P < 0.001). SCPA at less than 4 months of age did not increase the risk for adverse outcome (OR 1.2 (0.4-3.6), P = 0.78) but increased the risk for postoperative complications (OR 6.3 (2.3-14.9), P < 0.001). CONCLUSIONS SCPA can nowadays be performed in HLHS patients with low mortality. However, more than moderate tricuspid valve regurgitation should be targeted at surgery as it is a risk factor for adverse outcome such as death or need for cardiac transplant. SCPA should ideally be performed in children older than 4 months to minimise the risk of postoperative complications.

Monitoring of regional tissue oxygenation with near-infrared spectroscopy during the early postoperative course after superior cavopulmonary anastomosis

OBJECTIVES Near-infrared spectroscopy (NIRS) offers continuous non-invasive monitoring of regional tissue oxygenation. We evaluated NIRS monitoring during the postoperative course after superior cavopulmonary anastomosis in patients with hypoplastic left heart syndrome and anatomically related malformations. METHODS Cerebral (cSO(2)) and somatic (sSO(2)) tissue oxygenations were recorded for 48 h and compared with routine measures of intensive care monitoring. Changes in parameters in the case of postoperative complications were evaluated. RESULTS Data were obtained from 32 patients. Median age at operation was 2.9 (1.5-10.0) months and weight was 5.3 ± 1.0 kg. Postoperative complications occurred in 7 patients (pulmonary artery thrombus n = 4, pneumothorax n = 1, cardiopulmonary resuscitation n = 1 and low-cardiac output n = 1). cSO(2) was 44 ± 14% at the end of the operation and reached its minimum of 40 ± 11% 2 h later (P = 0.018). Overall, cSO(2) was depressed early after surgery and increased from a mean of 42 ± 11% during the first 4 postoperative hours to 57 ± 8% in the last 4 h of the study period (P < 0.001). The sSO(2) decreased from 77 ± 11% during the early postoperative course to 68 ± 9% within the later course (P < 0.001). The cSO(2) correlated with the arterial partial pressure of oxygen (pO(2), r = 0.364, P < 0.001), with the arterial oxygen saturation (SaO(2), r = 0.547, P < 0.001) and with the central venous oxygen saturation providing the strongest correlation (SvO(2), r = 0.686, P < 0.001). Analysis of agreement between cSO(2) and SvO(2) measurements revealed a mean bias of 0.97 with limits of agreement between 19.8 and -17.9%. Inclusion of both cSO(2) and sSO(2) into a linear regression model slightly improved the prediction of SvO(2) from NIRS values (r = 0.706, P < 0.001). The mean values of cSO(2), sSO(2), SaO(2) and SvO(2) during the early postoperative period were lower in patients with complications (cSO(2): 45 ± 9 vs 29 ± 5%, P < 0.001; sSO(2): 80 ± 11 vs 70 ± 6%, P = 0.004; SaO(2): 76 ± 8 vs 66 ± 6%, P = 0.004; SvO(2): 48 ± 14 vs 32 ± 6%, P < 0.001). CONCLUSIONS NIRS technology allows inferring the global oxygenation from continuous non-invasive measurements of regional tissue oxygenation. The cSO(2) is lowered in the early postoperative course. Lower cSO(2) values in the early postoperative course may be predictive of postoperative complications.

Cardiac Catheterization and Interventional Procedures as Part of Staged Surgical Palliation for Hypoplastic Left Heart Syndrome

BACKGROUND Cardiac catheterization and interventional procedures are an important part of staged surgical palliation for hypoplastic left heart syndrome (HLHS). METHODS We reviewed our experience of interventional procedures for HLHS patients treated between 01/1996 and 12/2010. RESULTS Overall, 222 neonates received a Norwood operation. Of them, 181 underwent 554 catheterizations with 243 interventions. Recoarctation was treated by balloon angioplasty (BA) in 46 patients. The pressure gradient dropped from 29 ± 14 mm Hg to 6 ± 7 mm Hg (P <.001); the diameter of the stenosis increased by 61 ± 33% (P <.001). Restenosis occurred in 16 cases and a higher initial gradient was predictive for the need of reintervention (odds ratio [OR] 1.057 [1.008-1.109] per 1 mm Hg increase, P =.022). The pressure gradient after reintervention was higher compared to the results of the first intervention (11 ± 7 mm Hg vs. 6 ± 7 mm Hg, P =.023). Aortopulmonary collaterals were detected in 25% (44/178) before hemi-Fontan operation, in 86% (117/136) before and in 37% (33/90) after Fontan completion. They were occluded in 98 patients during 119 catheterizations. Right-to-left shunts were found in 37 cases, mainly after Fontan completion (30/37). The baffle fenestration was closed in 48 of 90 patients after Fontan completion. Central venous pressure slightly increased (13.3 ± 1.7 mm Hg to 14.1 ± 1.9 mm Hg, P =.008) and SaO(2) increased from 88 ± 5% to 96 ± 2% (P <.001). Pulmonary artery stenosis was detected in nine of 136 patients after hemi-Fontan operation and addressed by catheter intervention in three cases (BA n = 2, stent implantation n = 1). Furthermore, miscellaneous interventions were performed during 12 catheterizations. CONCLUSION Although BA for recoarctation showed good acute results, the need for later reintervention is remarkably high. A higher initial gradient was predictive for restenosis. Pulmonary artery stenosis was a relatively rare problem and might be less likely with the hemi-Fontan technique.

Transapical mitral valved stent implantation: Enhanced survival and decreased paravalvular leakages

BACKGROUND/OBJECTIVES This study presents the recent results of transapical implantation of a new design of a mitral valved stent with up to three months follow-up. METHODS A self-expanding re-designed mitral valved stent was implanted via transapical approach into the beating heart of eight pigs. Echocardiographic- and hemodynamic parameters were assessed before (n=8), at 1h (n=8), at one month (n=6), at two months (n=2), and at three months (n=1) after implantation and a cardiac CT was conducted. RESULTS The stent was successfully deployed in all animals. Two animals died within the first month due to incorrect fixation force. Echocardiographic evaluation showed low gradients (3.9 ± 1.4 mm Hg and 1.9 ± 0.8 mm Hg across the valved stent and aortic valve) and a normal mitral annular plane systolic excursion (1.1 ± 0.2 cm) after one month. No paravalvular leakages (PVL) were detected after 1h. The pulmonary artery pressure did not increase after valved stent implantation (p ≥ 0.106). The pulmonary capillary wedge pressure (PCWP) slightly increased to 16 ± 3 mm Hg after one month (p=0.033). The left ventricular end-diastolic pressure was mildly elevated (15.8 ± 8.6 mm Hg) after one month. CONCLUSIONS Secure deployment and correct position of the valved stents were reproducibly achieved in the off-pump implantation procedure. No paravalvular leakages after 1h as well as low gradients, few stent fractures and a normal longitudinal function after one month were achieved with this newly developed and well-aligned prototype. However, a number of challenges have been identified during this study and potential for improvement has been identified.

Neuropsychological performance of school-aged children after staged surgical palliation of hypoplastic left heart syndrome

OBJECTIVES Despite advances in perioperative management during surgical treatment of hypoplastic left heart syndrome (HLHS), patients are still at risk for adverse neurodevelopmental sequelae including cognitive dysfunction. This study aimed to assess a neuropsychological profile of HLHS patients at school age who underwent the Norwood operation between 1996 and 2003 with deep hypothermic circulatory arrest (DHCA) or antegrade selective cerebral perfusion (ASCP), respectively. METHODS Forty HLHS patients (DHCA: n = 11 and ASCP: n = 29) were compared with healthy controls (DHCA controls: n = 10 and ASCP controls: n = 24), recruited according to age, sex and socioeconomic status. Neuropsychological assessment included non-verbal intelligence (IQ norms) and raw score measures of visual and verbal short- and long-term memory as well as executive functions, processing speed and concentration. Neuropsychological data were correlated with bypass and circulatory arrest times. RESULTS Compared with control subjects, both patient groups had average non-verbal intelligence scores [DHCA: 102 (72-112) and ASCP: 92 (70-127)], but showed reduced long-term memory capacities and decreased executive performance as well as reduced processing speed. DHCA patients, furthermore, had a reduced visual attention span, and ASCP patients scored less on the verbal learning task than controls. The duration of DHCA and cardiopulmonary bypass (CPB) was associated with visual executive functions and short-term memory. In the DHCA group, the duration of DHCA was correlated with the time to complete the Trail Making Test A measuring visual executive functions (Spearman rank correlation, rS = 0.867, P = 0.018). In patients provided with ASCP, the cumulated CPB duration was negatively correlated with the score of the block span test measuring visual short memory (rS = -0.476, P = 0.020) as well as with the copy score of the Rey Figure assessing visual executive functions (rS = -0.399, P = 0.032). CONCLUSIONS School-age children with HLHS who underwent the Norwood procedure either with DHCA or ASCP show cognitive impairments compared with healthy controls. Our data indicate deficits in specific cognitive domains such as memory, executive functions and processing speed rather than basic intellectual dysfunction.

Impact of afterload reduction strategies on regional tissue oxygenation after the Norwood procedure for hypoplastic left heart syndrome

OBJECTIVES Low cerebral tissue oxygenation saturations have been observed by near-infrared spectroscopy (NIRS) after the Norwood procedure. Altered cerebral vascular resistance and pharmacological afterload reduction redirecting blood flow away from the cerebral circulation are possible mechanisms. METHODS Two different afterload reduction strategies were evaluated in patients with hypoplastic left heart syndrome or variants after the Norwood procedure. In patients of Group 1 (n=34), afterload reduction was controlled with sodium nitroprusside or with the α-blocker phentolamine. In addition, a phosphodiesterase-III inhibitor was administered. Patients of Group 2 (n=34) received a phosphodiesterase-III inhibitor only. Cerebral and somatic tissue oxygenation saturations and routine intensive care monitoring data were recorded for 24 h before and 48 h after the Norwood procedure. Mean values of the last 4 preoperative (baseline) and of the first and last 4 postoperative hours (early and late course) were calculated. RESULTS Baseline, early and late cerebral saturations were 58±7, 52±9 and 60±6% for Group 1 and 58±7, 52±12 and 61±7% for Group 2 and somatic saturations were 59±8, 76±10 and 67±9% and 58±9, 78±8 and 69±10%, respectively. Regional saturations were not different between groups. The postoperative cerebral tissue oxygen saturation was below 40% for 50 (0-1040) min in Group 1 and for 45 (0-720) min in Group 2 (P=1.00). Preoperative cerebral NIRS values (OR 0.85 [0.76-0.96], P=0.007), age at operation (OR 1.39 [1.02-1.88], P=0.034) and early postoperative diastolic blood pressure (OR 0.88 [0.78-0.99], P=0.038) were associated with cerebral tissue oxygen saturations below 40% for more than 60 min. Patients with a prolonged period of low cerebral tissue oxygen saturation had longer duration of mechanical ventilation (69 (37-192) vs 60 (33-238) h, P=0.039) and afterload reduction therapy was terminated later (95 (47-696) vs 74 (39-650) h, P=0.006). Early mortality was 9.4% (3 of 32) compared with 2.8% (1 of 36) in the remainder (P=0.336). CONCLUSIONS The postoperative decline of cerebral tissue oxygen saturation was observed with both afterload reduction strategies. The difference between cerebral and somatic NIRS values may indicate a mismatch between cerebral and splanchnic oxygenation. Other strategies to improve cerebral tissue oxygenation are warranted.

Neuro-developmental outcome in single-ventricle patients: is the Norwood procedure a risk factor?

OBJECTIVES Complex neonatal surgery is considered a risk factor for neuro‐developmental impairment in single‐ventricle patients. Neuro‐developmental outcome was compared between preschool‐aged Fontan patients who underwent a Norwood procedure and single‐ventricle patients not requiring neonatal surgery with cardiopulmonary bypass. METHODS Verbal, performance and full‐scale intelligence quotient (IQ) were evaluated with the Wechsler Preschool and Primary Scale of Intelligence. Cognitive functions were assessed with the German ‘Kognitiver Entwicklungstest für das Kindergartenalter’ (KET‐KID). Risk factors for impaired neuro‐development were evaluated. RESULTS Neuro‐developmental assessment was completed in 95 patients (Norwood: n = 69; non‐Norwood: n = 26). Median (interquartile range) IQ and KET‐KID scores were in the normal range. Except for verbal KET‐KID, scores did not differ between Norwood and non‐Norwood patients (verbal IQ: 98 (86‐105) vs 93 (85‐102), P = 0.312; performance IQ: 91 (86‐100) vs 96 (86‐100), P = 0.932; full‐scale IQ: 93 (86‐101) vs 89 (84‐98), P = 0.314; KET‐KID verbal: 48 (17‐72) vs 25 (2‐54), P = 0.020; KET‐KID non‐verbal: 33 (18‐62) vs 45 (15‐54), P = 0.771; KET‐KID global: 42 (14‐65) vs 28 (6‐63), P = 0.208). Full‐scale IQ was below average (<85 points) in 14 (20%) Norwood and 9 (35%) non‐Norwood cases (P = 0.181). Global KET‐KID was below average (<16th percentile) in 19 (28%) and 10 (38%) patients (P = 0.326). Smaller head circumference z‐score and complications before neonatal surgery were independently associated with lower scores. CONCLUSIONS Neuro‐developmental outcome of preschool‐aged Fontan patients was in the normal range. The Norwood procedure was not a risk factor for neuro‐developmental impairment. Preoperative condition and patient‐related factors were more important determinants than variables related to surgical palliation.

Restrictive enlargement of the pulmonary annulus at repair of tetralogy of Fallot: a comparative 10-year follow-up study†

OBJECTIVES Since 1996, our centre performs restrictive enlargement of the pulmonary annulus at surgical repair of tetralogy of Fallot. A transannular patch is only used if the z-score of the pulmonary annulus is smaller than -2. We sought to determine whether this strategy reduces pulmonary insufficiency (PI) and reoperation rate compared to a nationwide contemporary cohort that has not been operated using a uniform strategy. METHODS Eighty-seven tetralogy of Fallot patients were included in the study (Group 1). One hundred sixty-seven tetralogy of Fallot patients from the Competence Network for Congenital Heart Disease served as controls (Group 2). Clinical, echocardiographic, electrocardiogram, cardiovascular magnetic resonance and outcome data were analysed. RESULTS Follow-up time since repair was not different between groups [12.9 (7.8-18.8) vs 13.1 (5.2-16.9) years, P = 0.96] while transannular patch rate was significantly lower in Group 1 (32.2% vs 64.7%, P < 0.001). Ten-year freedom from reoperation for PI was significantly higher in our cohort (98% vs 92%, P = 0.01). Multivariable analysis identified restrictive enlargement as the only predictor for no need of reoperation [hazard ratio 0.4 (95% confidence interval 0.24-0.84), P < 0.01]. In Group 1, cardiovascular magnetic resonance-derived volumes were smaller (indexed end-diastolic volume: 103 ± 24 vs 123 ± 31 ml/m2, P < 0.001; indexed end-systolic volume: 53 ± 19 vs 59 ± 20 ml/m2, P = 0.04) and regurgitation fraction was lower (21 ± 14 vs 31 ± 17%, P < 0.001). CONCLUSIONS Restrictive enlargement of the pulmonary annulus reduces PI and limits the amount of right ventricular dilatation at intermediate-term follow-up. The need for reoperation to alleviate PI is significantly lower compared to a contemporary cohort. Restrictive enlargement strategy has a stronger influence on freedom from reoperation than the use of a transannular patch. Clinical Trial Registration WHO Main ID: DRKS00010087. URL: http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00010087.