Olaf Jung

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.

Perioperative cerebral and somatic oxygenation in neonates with hypoplastic left heart syndrome or transposition of the great arteries

OBJECTIVE Significant depression in cerebral oxygen saturation has been observed in patients with hypoplastic left heart syndrome (HLHS) undergoing Norwood operations. We monitored cerebral oxygen saturation with near-infrared spectroscopy before and after this procedure. Patients with transposition of great arteries (TGA) before and after arterial switch operation were also studied to elucidate whether post-cardiopulmonary bypass (CPB) changes in cerebral oxygen saturation are related to CPB or hemodynamic alterations inherent in single-ventricle physiology. METHODS We monitored 33 patients with HLHS and 20 with TGA 24 hours before and 48 hours after CPB. In addition to cerebral oxygen saturation, routine measurements of oxygen transport and delivery were performed. RESULTS Preoperatively, cerebral oxygen saturation was higher in patients with HLHS than with TGA (61% ± 7% vs 56% ± 8%, P = .04). After CPB, cerebral oxygen saturation was markedly depressed in both groups but increased toward end of monitoring (HLHS vs TGA minimal value 42% ± 12% vs 54% ± 11%, P < .001, value 48 hours after CPB 62% ± 7% vs 80% ± 8%, P < .0001). Routine measures of oxygen delivery, such as arterial and central venous oxygen saturations, were similar at minimal cerebral oxygen saturation and 48 hours after CPB. CONCLUSIONS Depression of cerebral oxygen saturation is prevalent among neonates with congenital heart disease regardless of whether univentricular or biventricular circulation is present, suggesting that cerebral desaturation is mainly induced by CPBs effect on cerebral blood flow. Routine measures of oxygen delivery fail to indicate cerebral desaturation.

Restrictive enlargement of the pulmonary annulus at surgical repair of tetralogy of Fallot: 10-year experience with a uniform surgical strategy

OBJECTIVES Retrospective data suggest that a wide pulmonary annulus after Fallot repair aggravates pulmonary regurgitation. Therefore, since 1997, in our institution transannular patch enlargement was only intended for patients with a native pulmonary annulus z-score less than -4. If transannular patching was needed, enlargement was aimed to diameters within the range of a z-score of -2. We sought to determine whether this strategy of restrictive enlargement of the pulmonary annulus was adequate to reduce transannular patch rate and to limit pulmonary annulus width without increased right ventricular pressure load. METHODS Two-hundred-and-sixteen Fallot patients were retrospectively analysed. Ninety-eight patients underwent repair between 1997 and 2006 adhering to our uniform strategy (Group 1). One hundred and eighteen patients were operated between 1977 and 1996 without a uniform strategy (Group 2). Transannular patch rate, native and postoperative pulmonary annulus z-score, postoperative right ventricular outflow tract velocity on echocardiography and early reoperation rate for right ventricular outflow tract obstruction were analysed in both groups. RESULTS Compared to Group 2, patients in Group 1 were younger at repair, transannular patch rate was significantly reduced (32 vs 68%, p<0.0001) and postoperative pulmonary annulus diameters were smaller (z-score -2.1+/-1.5 vs 0.0+/-3.1, p<0.0001). However, no difference in right ventricular outflow tract velocity (2.4+/-0.8 vs 2.2+/-0.8m/s; p=NS) or the incidence of early reoperation for right ventricular outflow tract obstruction was found between the groups (3/98 vs 1/118; p=NS). CONCLUSION Restrictive enlargement of the pulmonary annulus at Fallot repair lowers transannular patch rate, limits the postoperative width of the pulmonary annulus but does not result in increased right ventricular pressure load or reoperation rate for residual right ventricular outflow tract obstruction. A limitation of postoperative pulmonary regurgitation can be expected when the extent of pulmonary annulus enlargement at repair is limited.

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.

The impact of afterload reduction on the early postoperative course after the Norwood operation — a 12-year single-centre experience

OBJECTIVE The objective of this study was to analyse the postoperative course and early outcome after the Norwood operation for patients with hypoplastic left heart syndrome. We particularly aimed to assess the impact of surgical and pharmacological modifications introduced. METHODS Of 157 patients who underwent the Norwood operation between January 1996 and December 2007, postoperative intensive care data on haemodynamics, pharmacological support and ventilation were analysed from 146 patients (six patients died intra-operatively and data were incomplete in five). The cohort was divided into three groups depending on the surgical method and type of afterload reduction. Patients of group 1 (n=39, January 1996-December 1999) were operated with deep hypothermic circulatory arrest. In patients of group 2 (n=59, January 2000-June 2003) and group 3 (n=59, July 2003-December 2007) antegrade selective cerebral perfusion was used. Patients of groups 1 and 2 received sodium nitroprusside to reduce afterload; in group 3 phentolamine was used. RESULTS There were no differences between the groups in terms of preoperative status and anatomy, except a higher incidence of prenatal diagnosis between groups 3 and 1. The duration and dosage of sodium nitroprusside administration were similar in groups 1 and 2. The median duration of afterload reduction was significantly longer in group 3 compared with both the other groups (72 h (range: 24-201 h) vs 48 h (range: 8-145 h) and 48 h (range: 4-173 h), respectively). The median ventilation times was shorter in group 2 compared with group 1 (61 h (range: 16-1191 h) vs 119 h (range: 26-648 h)). During the first 36 postoperative hours, the mean arterial blood pressure and coronary perfusion pressure were significantly lower in group 3 than in group 1 (50.7+/-4.8 and 28+/-3.7 mmHg vs 53.6+/-5.2 and 31.4+/-4.3 mmHg), but, in patients of group 3, the time period to consistently reach a mean arteriovenous oxygen difference below 5 ml dl(-1) was markedly shorter than in the other groups (group 3: 12h 4.90+/-1.97 ml dl(-1); group 1: 24h 4.53+/-2.25 ml dl(-1) and group 2: 24h 4.57+/-2.04 ml dl(-1)). Complication rates were similar between the groups. However, 30-day mortality decreased over the study period to an exponentially weighted moving average of 2.3%. CONCLUSION Adamant afterload reduction improves systemic blood flow early after the Norwood operation and may have contributed to the reduction in early postoperative mortality achieved over 12 years.

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.

Neurodevelopmental outcome in hypoplastic left heart syndrome: Impact of perioperative cerebral tissue oxygenation of the Norwood procedure

OBJECTIVES Patients with hypoplastic left heart syndrome are at risk for neurodevelopmental impairment. Hypoxic-ischemic brain injury during neonatal treatment might be a relevant cause. We evaluated the association between cerebral oxygenation in the perioperative course of the Norwood procedure and neurodevelopmental outcome. METHODS Cerebral tissue oxygen saturation (ScO2) was obtained by near-infrared spectroscopy for 24 hours before and 48 hours after surgery in 43 patients. Full-scale, verbal, and performance IQ scores were evaluated with the Wechsler Preschool and Primary Scale of Intelligence at a median of 4.5 years (range, 3.5-6.8 years). Cognitive functions were assessed with the German Kognitiver Entwicklungstest für das Kindergartenalter (KET-KID). RESULTS Mean IQ scores and KET-KID percentile ranks were in the lower-normal range (full-scale IQ, 94 ± 11; verbal IQ, 97 ± 13; performance IQ, 93 ± 9; KET-KID global, 42 ± 27; verbal, 48 ± 29; nonverbal, 37 ± 23). Scores were below average (full scale IQ <85 or KET-KID <16th percentile) in 12 cases. Mean preoperative ScO2 was lower in patients scoring below average (56.8% ± 7.1% vs 61.7% ± 5.8%; P = .028) and was correlated with full-scale IQ (r = 0.495; P = .001), verbal IQ (r = 0.524; P = .001), and performance IQ (r = 0.386; P = .012) scores, and with global (r = 0.360; P = .018) and verbal (r = 0.395, P = .009) KET-KID scores. A relationship between IQ or KET-KID scores and postoperative ScO2 was not found. Gestational age, head circumference z-score, age at surgery, and postoperative length of stay were associated with IQ and KET-KID scores. CONCLUSIONS Neurodevelopmental outcome was in the lower-normal range. Along with innate patient factors, preoperative cerebral tissue oxygenation is likely an important determinant of cognitive development.

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.