Pulmonary valve reconstruction for acquired pulmonary regurgitation in patients with treated congenital heart disease

OBJECTIVES

Pulmonary valve regurgitation is a common problem after relief of right ventricular outflow tract (RVOT) obstruction with a transannular patch. Pulmonary valve replacement with a homograft or xenograft is the routine treatment. Longevity of biological valves and the availability of homografts are limited. Alternatives to restore RVOT competence are evaluated. The goal of this study was to present intermediate-term results for pulmonary valve reconstruction (PVr) in patients with severe regurgitation.

METHODS

PVr was performed in 24 patients (August 2006‒July 2018). We analysed perioperative data, pre- and postoperative cardiac magnetic resonance (CMR) imaging studies, freedom from valve replacement and risk factors for pulmonary valve dysfunction.

RESULTS

The underlying diagnoses were tetralogy of Fallot (n = 18, 75%), pulmonary stenosis (n = 5, 20.8%) and the double outlet right ventricle post banding procedure (n = 1, 4.2%). The median age was 21.5 (14.8-23.7) years. Main (n = 9, 37.5%) and branch pulmonary artery procedures (n = 6, 25%) and surgery of the RVOT (n = 16, 30.2%) were often part of the reconstruction. The median follow-up after the operation was 8.0 (4.7-9.7) years. Freedom from valve failure was 96% at 2 and 90% at 5 years. The mean longevity of the reconstructive surgery was 9.9 years (95% confidence interval: 8.8-11.1 years). CMR before and 6 months after surgery showed a reduction in the regurgitation fraction [41% (33-55) vs 20% (18-27) P = 0.00] and of the indexed right ventricular end-diastolic volume [156 ml/m2 (149-175) vs 116 ml/m2 (100-143), P = 0.004]. Peak velocity across the pulmonary valve (determined by CMR) half a year after surgery was 2.0, unchanged.

CONCLUSIONS

PVr can be achieved with acceptable intermediate-term results and may delay pulmonary valve replacement.

Effect of Leisure Sports on Exercise Capacity and Quality of Life in Patients with a Fontan Circulation

Despite improvement in survival, patients with a Fontan circulation are at risk for numerous complications, and exercise capacity and quality of life are usually reduced compared with healthy controls. However, only a few studies have assessed the impact of the amount of sporting activity on exercise capacity and health-related quality of life. We analyzed cardiopulmonary exercise tests (CPET) in a large cohort of patients with a Fontan circulation. Questionnaires were used to assess health-related quality of life and sporting activity. A total of 79 patients with a median age of 13.0 (6.5 to 34.4) years at CPET were included (female, n = 31). Questionnaires revealed that 80% of patients (n = 63) do leisure sports with 43% (n = 27) exercising more than 2 hours per /week. In a subgroup analysis on pediatric patients (n = 52) we found that nearly all participate in school sports (n = 51) and report good subjective health (n = 48). In the pediatric subgroup, oxygen uptake at the anaerobic threshold and peak oxygen uptake correlated with subjective health (p <0.05) and the amount of leisure sports activity (p <0.01). In the overall cohort, running time and running distance were significantly associated with the hours of sports per week (p <0.01). CPET results did not significantly differ between single right and single left ventricle patients. Furthermore, an open fenestration was not associated with reduced exercise capacity. In conclusion, most patients with a Fontan circulation participate in leisure sports and report good subjective healthiness. In pediatric patients, increased sports activity is associated with better exercise capacity and subjective healthiness.

Serial Assessment of Right Ventricular Deformation in Patients With Hypoplastic Left Heart Syndrome: A Cardiovascular Magnetic Resonance Feature Tracking Study

Background As right ventricular dysfunction is a major cause of adverse outcome in patients with hypoplastic left heart syndrome, the aim was to assess right ventricular function and deformation after Fontan completion by performing 2-dimensional cardiovascular magnetic resonance feature tracking in serial cardiovascular magnetic resonance studies. Methods and Results Cardiovascular magnetic resonance examinations of 108 patients with hypoplastic left heart syndrome (female: 31) were analyzed. Short-axis cine images were used for right ventricular volumetry. Two-dimensional cardiovascular magnetic resonance feature tracking was performed using long-axis and short-axis cine images to measure myocardial global longitudinal, circumferential, and radial strain. All patients had at least 2 cardiovascular magnetic resonance examinations after Fontan completion and 41 patients had 3 examinations. Global strain values and right ventricular ejection fraction decreased from the first to the third examination with a significant decline in global longitudinal strain from the first examination to the second examination (median, first, and third quartile: -18.8%, [-20.5;-16.5] versus -16.9%, [-19.3;-14.7]) and from the first to the third examination in 41 patients (-18.6%, [-20.9;-15.7] versus -15.8%, [-18.7;-12.6]; P-values <0.004). Right ventricular ejection fraction decreased significantly from the first to the third examination (55.4%, [49.8;59.3] versus 50.2%, [45.0;55.9]; P<0.002) and from the second to the third examination (53.8%, [47.2;58.7] versus 50.2%, [45.0;55.9]; P<0.0002). Conclusions Serial assessment of cardiovascular magnetic resonance studies in patients with hypoplastic left heart syndrome after Fontan completion demonstrates a significant reduction in global strain values and right ventricular ejection fraction at follow-up. The significant reduction in global longitudinal strain between the first 2 examinations with non-significant changes in right ventricular ejection fraction suggest that global longitudinal strain measured by 2-dimensional cardiovascular magnetic resonance feature tracking might be a superior technique for the detection of changes in myocardial function.

Non-contrast enhanced magnetic resonance imaging for characterization of Fontan associated liver disease

OBJECTIVES

To evaluate the ability of non-contrast enhanced magnetic resonance imaging (MRI) techniques to characterize Fontan associated liver disease (FALD) in adolescent and adult Fontan patients.

METHODS

Fontan patients (n = 29) and healthy controls (n = 13) underwent an MRI protocol with T₁, T₂ and Apparent Diffusion Coefficient (ADC) mapping. Routine FALD screening included abdominal ultrasound and laboratory testing.

RESULTS

Median follow-up after Fontan operation was 15.1 (IQR 12.0-16.8) years. Distinct differences in tissue characteristics were visualized. T₁ and T₂ relaxation times were prolonged in Fontan patients, particularly of the right lobe (T₁: 745 (IQR 715-784) ms vs. 586 (IQR 555-602) ms, p < 0.001; T₂: 63 (IQR 59-64) ms vs. 58 (IQR 56-60) ms, p = 0.002). Left lobe ADC was lower in Fontan patients (1.10 (IQR 1.06-1.18) x 10^-3 mm²/s vs. 1.23 (IQR 1.19-1.29) x 10^-3 mm²/s, p < 0.001). T₂ mapping was able to differentiate between controls and Fontan patients with different FALD severity. Right lobe T₂ was higher in patients with moderate or severe in comparison to those with no or mild changes and healthy controls (64 (IQR 61-67) ms vs. 60 (IQR 59-63) ms vs. 58 (IQR 56-60) ms, p = 0.001).

CONCLUSIONS

Non-contrast enhanced MRI methods are able to visualize regional differences in liver tissue characteristics. T₁ and T₂ relaxation times were prolonged in Fontan patients suggestive of fibrosis or congestive hepatopathy, while reduced ADC might reflect impaired microperfusion. These methods have promising clinical potential for detection of liver abnormalities in Fontan patients. The usefulness of T₂ mapping to grade FALD severity merits further investigation.

Pulmonary vascular disease in Fontan circulation-is there a rationale for pulmonary vasodilator therapies?

The Fontan circulation is a palliative concept for patients with univentricular hearts. The central veins are connected directly to the pulmonary arteries (cavo-pulmonary connection) to separate the pulmonary and the systemic circulation. There is no sub-pulmonary ventricle that generates pressure to drive blood through the pulmonary arteries. Pulmonary blood flow is determined by central venous pressure (CVP) and pulmonary vascular resistance (PVR). The capability of the Fontan circulation to compensate for alterations in PVR is limited, as CVP can only be increased within narrow ranges without adverse clinical consequences. Consequently, systemic ventricular preload and cardiac output are dependent on a healthy lung with low PVR. Failure of the Fontan circulation is relatively common. In addition to ventricular dysfunction, maladaptive pulmonary vascular remodeling resulting in increased pulmonary resistance may play a key role. The pathophysiology of the maladaptive vascular processes remains largely unclear and diagnosis of an increased PVR is challenging in Fontan circulation as accurate measurement of pulmonary arterial blood flow is difficult. In the absence of a sub-pulmonary ventricle, pulmonary artery pressure will almost never reach the threshold conventionally used to define pulmonary arterial hypertension. There is a need for markers of pulmonary vascular disease complementary to invasive hemodynamic data in Fontan patients. In order to treat or prevent failure of the Fontan circulation, pathophysiological considerations support the use of pulmonary vasodilators to augment pulmonary blood flow and systemic ventricular preload and lower CVP. However, to date the available trial data have neither yielded enough evidence to support routine use of pulmonary vasodilators in every Fontan patient nor have they been helpful in defining subgroups of patients that might benefit from such therapies. This review discusses potential pathomechanisms of pulmonary vascular disease; it summarizes the current knowledge of the effects and efficacy of pulmonary vasodilator therapy in Fontan patients and tries to outline areas of potential future research on the diagnosis and treatment of pulmonary vascular disease and Fontan failure.

Transcatheter pulmonary valve replacement: a new polycarbonate urethane valve

OBJECTIVES

Transcatheter pulmonary valve replacement has become a valid treatment option for right ventricular outflow tract diseases. However, some limitations occur in patients with wide, compliant right ventricular outflow tracts that might be amenable to treatment with self-expanding valved protheses. An experimental ovine study was designed to evaluate a novel dip-coated, low-profile trileaflet polycarbonate urethane (PCU) heart valve mounted into a self-expandable nitinol stent.

METHODS

The PCU valves were produced by a dip-coating technique, mounted in a conical-shaped nitinol stent and provided with a leaflet thickness of 100-150 µm. The valved stents were implanted percutaneously via transfemoral access in 6 consecutive sheep divided into 2 groups. Three animals were followed up for 1 month and the remainder, for 6 months. Angiographic measurements and transthoracic echocardiography were performed before and after implantation and at the end of the 1- or 6-month observation period, respectively.

RESULTS

Orthotopic positioning of the valve was achieved in all animals. All except 1 had competent valves during the follow-up period. The peak-to-peak gradient across the PCU valved stents was 4.6 ± 1.0 mmHg after 1 month and 4.4 ± 2.3 mmHg after 6 months of follow-up. Macroscopic and microscopic post-mortem evaluation indicated good morphological and structural results. There were no stent fractures, leaflet calcification or thrombus formation.

CONCLUSIONS

This study demonstrates successful transcatheter pulmonary valve replacement with a novel dip-coated valved nitinol stent. The trileaflet PCU prostheses indicated good functional and biocompatible properties after a 6-month observation period.

Surveillance of Fontan Associated Liver Disease in Childhood and Adolescence

Fontan associated liver disease (FALD) has been recognized as a potentially serious sequela of the Fontan circulation. Prevalence of FALD among different age groups and risk factors for advanced changes were assessed. FALD screening included abdominal ultrasound and laboratory tests. A "liver disease score (LDS)" incorporating items from ultrasound and blood testing was calculated to grade FALD severity (5 items each, maximum score 10 points). 240 patients (male: n = 139, female: n = 101, systemic right ventricle: n = 160) underwent FALD screening 10 (IQR 7-15) years after Fontan surgery. Ultrasound was abnormal in 184 (76.6%) patients (surface nodularity / blunted liver edge: n = 133, 55.4%; heterogeneous parenchyma: n = 93, 38.8%; splenomegaly: n = 68, 28.3%; ascites: n = 23, 9.6%). At least one abnormal laboratory test was detected in 218 (90.8%) patients. Gamma-glutamyl-transpeptidase was elevated in the majority of patients (n = 206, 85.8%). Median LDS was 3 (2-4). Scores ≥5 were observed in 32 (13.3%) patients. Longer follow-up (15 (11-20) vs 9 (6-14) years, P <0.001), higher central venous (13 (11-15) vs 10 (9-12) mmHg, P <0.001) and end-diastolic pressure (8 (5-10) vs 6 (5-7) mmHg, P = 0.001), impaired ventricular function and absence of sinus rhythm were associated with LDS ≥5. Longer follow-up (OR 1.2 (1.1-1.3), P <0.001) and higher central venous pressure (OR 1.6 (1.3-2.1), p < 0.001) were the only independent predictors of advanced FALD. Abdominal ultrasound and laboratory abnormalities suggestive of FALD are common during routine follow-up already in childhood and adolescence irrespective of ventricular morphology. More advanced findings are associated with longer follow-up and higher central venous pressure.

Right ventricular outflow tract reconstruction with the Labcor® stentless valved pulmonary conduit

OBJECTIVES

The right ventricular outflow tract reconstruction is a common necessity in congenital cardiac surgery. As homograft availability is limited, alternatives need to be evaluated. The Labcor® conduit consists of a porcine tricomposite valve assembled inside a bovine pericardium tube. This study presents intermediate-term results for its utilization for right ventricular outflow tract reconstruction.

METHODS

Labcor conduits were implanted in 53 patients (February 2009-July 2016). We analysed perioperative data, freedom from conduit failure and risk factors for conduit dysfunction.

RESULTS

The most common diagnosis was Tetralogy of Fallot (n = 20, 37.7%). The median age at surgery was 10.0 [interquartile range (IQR) 4.9-14.3] years. Pulmonary artery plasty (n = 37, 69.8%) and augmentation of the right ventricular outflow tract (n = 16, 30.2%) were often part of the procedure. The median conduit size was 21 (range 11-25) mm. There was no in-hospital death. The median follow-up after surgery was 4.6 (IQR 3.4-5.6) years. Fourteen patients (27.5%) developed conduit failure with stenosis being the main cause. Freedom from conduit failure was 98.0% at 2 and 80.5% at 5 years. The median longevity of the conduit was 7.4 years (95% confidence interval 5.1-9.8 years). Younger age and smaller conduit size were related to conduit failure.

CONCLUSIONS

Utilization of the Labcor conduit revealed acceptable intermediate-term results. The conduit appeared to be functioning sufficiently well within the first 5 years in the majority of patients. The higher rate of failure concerning smaller conduits might be associated with somatic outgrowth; however, conduit degeneration as common and long-term outcome still needs to be evaluated.

Glial Fibrillary Acid Protein and Cerebral Oxygenation in Neonates Undergoing Cardiac Surgery

BACKGROUND

 Neonates undergoing surgery for complex congenital heart disease are at risk of developmental impairment. Hypoxic-ischemic brain injury might be a contributing factor. We aimed to investigate the perioperative release of the astrocyte cytoskeleton component glial fibrillary acid protein and its relation to cerebral oxygenation.

METHODS

 Serum glial fibrillary acid protein levels were measured before and 0, 12, 24, and 48 hours after surgery. Reference values were based on preoperative samples; concentrations above the 95th percentile were defined as elevated. Cerebral oxygenation was derived by near-infrared spectroscopy.

RESULTS

 Thirty-six neonates undergoing 38 surgeries utilizing cardiopulmonary bypass were enrolled (complete data available for 35 procedures). Glial fibrillary acid protein was elevated after 18 surgeries (arterial switch: 7/12; Norwood: 5/15; others: 6/8; p = 0.144). Age at surgery was higher in cases with elevated serum levels (6 [4-7] vs. 4 [2-5] days, p = 0.009) and intraoperative cerebral oxygen saturation was lower (70 ± 10% vs. 77 ± 7%, p = 0.029). In cases with elevated postoperative glial fibrillary acid protein, preoperative cerebral oxygen saturation was lower for neonates undergoing the arterial switch operation (55 ± 9% vs. 64 ± 4%, p = 0.048) and age at surgery was higher for neonates with a Norwood procedure (7 [6-8] vs. 5 [4-6] days, p = 0.028).

CONCLUSIONS

 Glial fibrillary acid protein was elevated after ∼50% of neonatal cardiac surgeries and was related to cerebral oxygenation and older age at surgery. The potential value as a biomarker for cerebral injury after neonatal cardiac surgery warrants further investigation; in particular, the association with neurodevelopmental outcome needs to be determined.

S100B and its relation to cerebral oxygenation in neonates and infants undergoing surgery for congenital heart disease

OBJECTIVES

Neonates and infants undergoing surgery for congenital heart disease are at risk for developmental impairment. Hypoxic-ischemic brain injury might be one contributing factor. We aimed to investigate the perioperative release of the astrocyte protein S100B and its relation to cerebral oxygenation.

METHODS

Serum S100B was measured before and 0, 12, 24, and 48 hours after surgery. Cerebral oxygen saturation was derived by near-infrared spectroscopy. S100B reference values based on preoperative samples; concentrations above the 75th percentile were defined as elevated. Patients with elevated S100B at 24 or 48 hours were compared to cases with S100B in the normal range. Neonates (≤28 days) and infants (>28 and ≤365 days) were analyzed separately due to age-dependent release of S100B.

RESULTS

Seventy-four patients underwent 94 surgical procedures (neonates, n = 38; infants, n = 56). S100B concentrations were higher in neonates before and after surgery at all time points (P ≤ .015). Highest values were noticed immediately after surgery. Postoperative S100B was elevated after 15 (40.5%) surgeries in neonates. There was no difference in pre-, intra-, or postoperative cerebral oxygenation. In infants, postoperative S100B was elevated after 23 (41.8%) procedures. Preoperative cerebral oxygen saturations tended to be lower (53 ± 12% vs 59 ± 12%, P = .069) and arterial-cerebral oxygen saturation difference was higher (35 ± 11% vs 28 ± 11%, P = .018) in infants with elevated postoperative S100B. In the early postoperative course, cerebral oxygen saturation was lower (54 ± 13% vs 63 ± 12%, P = .011) and arterial-cerebral oxygen saturation difference was wider (38 ± 11% vs 30 ± 10%, P = .008). Cerebral oxygen saturation was also lower for the entire postoperative course (62 ± 18% vs 67 ± 9%, P = .047).

CONCLUSIONS

Postoperative S100B was elevated in about 40% of neonates and infants undergoing cardiac surgery. Infants with elevated postoperative S100B had impaired perioperative cerebral tissue oxygenation. No relation between S100B and cerebral oxygenation could be demonstrated in neonates.

Longitudinal Deformation of the Right Ventricle in Hypoplastic Left Heart Syndrome: A Comparative Study of 2D-Feature Tracking Magnetic Resonance Imaging and 2D-Speckle Tracking Echocardiography

In hypoplastic left heart syndrome (HLHS), long-term outcome is closely related to right ventricular function. Echocardiography and magnetic resonance imaging (MRI) are routinely used for functional assessment. MRI 2D-tissue feature tracking (2D-FT) allows quantification of myocardial deformation but has not yet been applied to HLHS patients. We sought to investigate the feasibility of this technique and to compare the results to 2D-speckle tracking echocardiography (2D-STE). In routine MRI 2D anatomical four chamber view, cine images were recorded in 55 HLHS patients (median age 4.9 years [1.6, 17.0]). Regional and global peak systolic longitudinal strain (LS) and strain rate (LSR) were determined using 2D-FT software. Echocardiographic four chamber view was analyzed with 2D-STE. Visualization of all myocardial segments with MRI was excellent, regional, and global LS and LSR could be assessed in all data sets. In 2D-STE, 28% of apical segments could not be analyzed due to poor image quality. Agreement of 2D-FT MRI and 2D-STE was acceptable for global LS, but poor for global LSR. In MRI, regional LS was lower in the septal segments, while LSR was not different between the segments. GLS and GLSR correlated with ejection fraction (GLS: r = - 0.45 and r < 0.001, GLSR: r = - 0.34 and p = 0.01). With new post-processing options, the assessment of regional and global LS and LSR is feasible in routine MRI of HLHS patients. For LS, results were comparable with 2D-STE. The agreement was poor for LSR, which might relate to differences in temporal resolution between the two imaging modalities.

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.

Decline of Systolic and Diastolic 2D Strain Rate During Follow-Up of HLHS Patients After Fontan Palliation

Accurate assessment of ventricular function is particularly important in children with hypoplastic left heart syndrome (HLHS) after completion of the total cavopulmonary connection (TCPC). For this purpose, two-dimensional speckle tracking (2DST) is a promising technique as it does not depend on the angle of insonation or the geometry of the ventricle. The objective of this study was to assess changes in systolic and diastolic right ventricular (RV) function within a 5-year follow-up period of HLHS patients after TCPC using conventional and 2DST echocardiography. RV fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE), E/A, E/e' and 2DST parameters [global longitudinal peak systolic strain (GS) and strain rate (GSRs), global strain rate in early (GSRe) and late (GSRa) diastole] of 40 HLHS patients were compared at 1.6 and at 5.1 years after TCPC. RVFAC, E/A, E/e' and GS did not change, whereas TAPSE (13.7 ± 3.2 vs. 10.5 ± 2.4 mm/m(2), p < 0.001), GSRs (-1.56 ± 0.28 vs. -1.35 ± 0.31 1/s, p < 0.001), GSRe (2.22 ± 0.49 vs. 1.96 ± 0.44 1/s, p = 0.004) and GSRa (1.19 ± 0.39 vs. 0.92 ± 0.39 1/s, p < 0.001) decreased significantly. Systolic and diastolic RV function parameters of HLHS patients decreased from 1.6 to 5.1 years after TCPC in our patients. Changes in global strain rate parameters may be signaling early RV dysfunction that is not detectable by traditional echocardiography. Further study is needed to verify this and to determine whether these changes are clinically relevant.

Normal values of aortic dimensions, distensibility, and pulse wave velocity in children and young adults: a cross-sectional study

BACKGROUND

Aortic enlargement and impaired bioelasticity are of interest in several cardiac and non-cardiac diseases as they can lead to cardiovascular complications. Cardiovascular magnetic resonance (CMR) is increasingly accepted as a noninvasive tool in cardiovascular evaluation. Assessment of aortic anatomy and bioelasticity, namely aortic distensibility and pulse wave velocity (PWV), by CMR is accurate and reproducible and could help to identify anatomical and bioelastic abnormalities of the aorta. However, normal CMR values for healthy children and young adults are lacking.

METHODS

Seventy-one heart-healthy subjects (age 16.4 ± 7.6 years, range 2.3-28.3 years) were examined using a 3.0 Tesla CMR scanner. Aortic cross-sectional areas and aortic distensibility were measured at four positions of the ascending and descending thoracic aorta. PWV was assessed from aortic blood flow velocity measurements in a aortic segment between the ascending aorta and the proximal descending aorta. The Lambda-Mu-Sigma (LMS) method was used to obtain percentile curves for aortic cross-sectional areas, aortic distensibility and PWV according to age.

RESULTS

Aortic areas, PWV and aortic distensibility (aortic cross-sectional areas: r = 0.8 to 0.9, p < 0.001; PWV: r = 0.25 to 0.32, p = 0.047 to 0.009; aortic distensibility r = -0.43 to -0.62, p < 0.001) correlated with height, weight, body surface area, and age. There were no significant sex differences.

CONCLUSIONS

This study provides percentile curves for cross-sectional areas, distensibility and pulse wave velocity of the thoracic aorta in children and young adolescents between their 3rd and 29th year of life. These data may serve as a reference for the detection of pathological changes of the aorta in cardiovascular disease.

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.

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.

A nonlinear operator-based speech feature analysis method with application to vocal fold pathology assessment

Traditional speech processing methods for laryngeal pathology assessment assume linear speech production with measures derived from an estimated glottal flow waveform. They normally require the speaker to achieve complete glottal closure, which for many vocal fold pathologies cannot be accomplished. To address this issue, a nonlinear signal processing approach is proposed which does not require direct glottal flow waveform estimation. This technique is motivated by earlier studies of airflow characterization for human speech production. The proposed nonlinear approach employs a differential Teager energy operator and the energy separation algorithm to obtain formant AM and FM modulations from filtered speech recordings. A new speech measure is proposed based on parameterization of the autocorrelation envelope of the AM response. This approach is shown to achieve impressive detection performance for a set of muscular tension dysphonias. Unlike flow characterization using numerical solutions of Navier-Stokes equations, this method is extremely computationally attractive, requiring only a small time window of speech samples. The new noninvasive method shows that a fast, effective digital speech processing technique can be developed for vocal fold pathology assessment without the need for direct glottal flow estimation or complete glottal closure by the speaker. The proposed method also confirms that alternative nonlinear methods can begin to address the limitations of previous linear approaches for speech pathology assessment.

Direct speech feature estimation using an iterative EM algorithm for vocal fold pathology detection

The focus of this study is to formulate a speech parameter estimation algorithm for analysis/detection of vocal fold pathology. The speech processing algorithm proposed estimates features necessary to formulate a stochastic model to characterize healthy and pathology conditions from speech recordings. The general idea is to separate speech components under healthy and assumed pathology conditions. This problem is addressed using an iterative maximum-likelihood (ML) estimation procedure, based on the estimation-maximization (EM) algorithm. A new feature for characterizing pathology, termed enhanced-spectral-pathology component (ESPC), is estimated and shown to vary consistently between healthy and pathology conditions. It is also shown that the mean-area-peak-value (MAPV) and the weighted-slope (WSLOPE) indexes, which are obtained from the ESPC estimate, are meaningful measures of speech pathology conditions. For classification purposes, a five-state hidden-Markov-model (HMM) recognizer was formulated, based on the MAPV, WSLOPE, and ESPC spectral features. A set of log Mel-frequency filter bank coefficients were used to parameterize the ESPC feature. An evaluation of the HMM-based classifier was performed using speech recordings from healthy and vocal fold cancer patients of sustained vowel sounds. It is shown that while both MAPV and WSLOPE are useful features for vocal fold pathology detection, superior performance was achieved using a finer spectral representation of ESPC (e.g., a detection rate of 88.7% for pathology and 92.8% for healthy condition). One main advantage of the proposed method is that it does not require direct estimation of the glottal flow waveform. Therefore, the limitation of the inability to characterize vocal fold pathology, due to incomplete glottal closure, is no longer an issue. The results suggest that general analysis of the ESPC feature can provide a quantitative, noninvasive approach for analysis, detection, and characterization of speech production under vocal fold pathology.

A noninvasive technique for detecting hypernasal speech using a nonlinear operator

Speakers with a defective velopharyngeal mechanism produce speech with inappropriate nasal resonance (hypernasal speech). It is of clinical interest to detect hypernasality as it is indicative of an anatomical, neurological, or peripheral nervous system problem. There are various clinical techniques used to determine hypernasality. The current techniques are physically invasive or intrusive to some extent. A preferred approach for detecting hypernasality, would be noninvasive to maximize patient comfort and naturalness of speaking. In this study, a noninvasive technique based on the Teager Energy operator is proposed. Utilizing a property of the Teager Energy operator and a model for normal and nasalized speech, a significant difference between the Teager Energy profile for lowpass and bandpass filtered nasalized speech is shown. This difference is shown to be nonexistent for normal speech. A classification algorithm is formulated that detects the presence of hypernasality using a measure of the difference in the Teager Energy profiles. The classification algorithm was evaluated using a native English speaker population producing front (/i/) and mid (/A/) vowels. Results show that the presence of hypernasality in speech can be reliably detected using the proposed classification algorithm.

Robust estimation of speech in noisy backgrounds based on aspects of the auditory process

A new approach to speech enhancement is proposed where constraints based on aspects of the auditory process augment an iterative enhancement framework. The basic enhancement framework is based on a previously developed dual-channel scenario using a two-step iterative Wiener filtering algorithm. Constraints across broad speech sections and over iterations are then experimentally developed on a novel auditory representation derived by transforming the speech magnitude spectrum. The spectral transformations are based on modeling aspects of the human auditory process which include critical band filtering, intensity-to-loudness conversion, and lateral inhibition. The auditory transformations and perceptual based constraints are shown to result in a new set of auditory constrained and enhanced linear prediction (ACE-LP) parameters. The ACE-LP based speech spectrum is then incorporated into the iterative Wiener filtering framework. The improvements due to auditory constraints are demonstrated in several areas. The proposed auditory representation is shown to result in improved spectral characterization in background noise. The auditory constrained iterative enhancement (ACE-II) algorithm is shown to result in improved quality over all sections of enhanced speech. Adaptation of auditory based constraints to changing spectral characteristics over broad classes of speech is another novel aspect of the proposed algorithm. The consistency of speech quality improvement for the ACE-II algorithm is illustrated over time and across all phonemes classified over a large set of phonetically balanced sentences from the TIMIT database. This study demonstrates the application of auditory based perceptual properties of a human listener to speech enhancement in noise, resulting in improved and consistent speech quality over all regions of speech.

Objective speech quality assessment and the RPE-LTP coding algorithm in different noise and language conditions

The formulation of reliable signal processing algorithms for speech coding and synthesis require the selection of a prior criterion of performance. Though coding efficiency (bits/second) or computational requirements can be used, a final performance measure must always include speech quality. In this paper, three objective speech quality measures are considered with respect to quality assessment for American English, noisy American English, and noise-free versions of seven languages. The purpose is to determine whether objective quality measures can be used to quantify changes in quality for a given voice coding method, with a known subjective performance level, as background noise or language conditions are changed. The speech coding algorithm chosen is regular-pulse excitation with long-term prediction (RPE-LTP), which has been chosen as the standard voice compression algorithm for the European Digital Mobile Radio system. Three areas are considered for objective quality assessment which include: (i) vocoder performance for American English in a noise-free environment, (ii) speech quality variation for three additive background noise sources, and (iii) noise-free performance for seven languages which include English, Japanese, Finnish, German, Hindi, Spanish, and French. It is suggested that although existing objective quality measures will never replace subjective testing, they can be a useful means of assessing changes in performance, identifying areas for improvement in algorithm design, and augmenting subjective quality tests for voice coding/compression algorithms in noise-free, noisy, and/or non-English applications.

Postoperative computed tomography three months after lumbar disc surgery. A prospective single-blind study

In a prospective single-blind study, 60 patients surgically treated for lumbar disc herniation underwent clinical examination and computed tomography preoperatively and 3 months after surgery. At follow-up (58 patients; median, 31 months; range, 21-37 months), 29 patients had an excellent outcome (51%), 20 improved (33%), and 9 were unchanged or worse (16%). Dural or radicular scar tissue was present by computed tomography in 88% of the patients, but the findings could not be correlated with the clinical outcome. Recurrent or persistent disc herniation was found in 9% of the patients. The clinical outcome of patients with abnormal computed tomography did not differ significantly from patients without this finding. A relation between facet joint degeneration and less successful clinical outcome was demonstrated. Computed tomography (without contrast) 3 months after surgery gave little information which could be correlated with the clinical outcome. Patients with an excellent outcome had all degrees of intraspinal scar tissue.

[Symptomatic pelvic girdle relaxation. Clinical aspects]

In pregnancy a relaxation of the sacroiliac joints and the symphysis is a physiologic phenomenon which usually occurs without symptoms. In some cases, however, these changes cause characteristic symptoms, with pain and difficulty in walking: the symptomatic pelvic girdle relaxation. The condition may be confirmed by tenderness of the joints and provocation of pain by the sacroiliac joints tests. Usually the symptoms disappear shortly after giving birth, but some women suffer for several months, and a few suffer persistent symptoms, the pelvic joint syndrome.

Sleep cystometries in children with nocturnal enuresis

A combined analysis was done of sleep and bladder filling during sleep. Cystometry did not specifically affect sleep, since most of the cystometry studies in cases of enuresis did not lead to sleep stage changes on electroencephalography. Bladder instability was not accompanied by lighter sleep. Increasing patient age did not appear to have any influence on sleep or bladder behavior. We conclude that it is possible to provoke enuresis at any sleep stage and that sleep is unaffected by bladder filling in enuretic patients.

Electroencephalographic changes in patients with herpes zoster

EEGs of 42 patients with herpes zoster and 6 with herpes zoster-associated encephalitis were studied to characterize the nature and prevalence of EEG abnormalities in apparently uncomplicated herpes zoster. Thirty-one percent of herpes zoster patients had EEG changes with reduced rhythm frequency ranging from 7 to 2 Hz activity. Frontotemporal localization was observed in 54% of the abnormal EEGs. When compared to EEG in herpes zoster associated encephalitis, the findings were qualitatively the same, but tended to be more severe in the encephalitis cases. No effect of acyclovir on the EEG could be demonstrated.

Acupuncture treatment of chronic tension headache--a controlled cross-over trial

In a controlled trial the effect of traditional Chinese acupuncture v. placebo acupuncture was evaluated in 18 patients with chronic tension headache (mean disease duration 15 years). All patients suffered from daily or frequently recurring headache, the intensity of which was recorded by the patient over a period of 15 weeks. Each patient was treated by traditional Chinese acupuncture as well as by placebo acupuncture in a cross-over design following randomization. Each period of treatment comprised six treatments. Traditional Chinese acupuncture was found to be significantly more pain-relieving than placebo acupuncture, according to the pain registration of the patients themselves. The pain reduction was 31%. Acupuncture is therefore found to be a reasonable treatment for chronic tension headache.

Simultaneous registration of sleep-stages and bladder activity in enuresis

A combined monitoring of sleep stages and bladder activity for the evaluation of enuresis is on trial. Polygraphic recordings in 7 patients, comprising the preliminary material, have shown single-event bladder contractions without forewarning or changes in sleep stages. A volume dependency of the enuresis episodes seems so far to be a major mechanism.

Acute urinary retention in first trimester of pregnancy

A 34-year old pregnant women with retroverted uterus and suffering from acute attacks of urinary retention in the first trimester of pregnancy is described. The attacks of retention were caused by the enlarged retroverted uterus associated with a 1x1 cm, well differentiated papilliferous carcinoma in the right side of the trigone. The urinary symptom disappeared after resection of the tumor.

Failure of proximal gastric vagotomy for duodenal ulcer resistant to cimetidine

45 patients with uncomplicated duodenal ulcer who did not respond to cimetidine underwent elective proximal gastric vagotomy (PGV). 39 of these, who had received cimetidine for an average of 5.2 months before surgery, were followed up for 20-67 months postoperatively. 18(46%) of them were classified as grade IV (ie, failures) according to a modified Visick scale--17 (44%) had a recurrent peptic ulcer. Augmented histamine tests done in 17 patients showed an expected reduction of peak acid output, so maintenance of stomach acidity was unlikely to be a cause of failure of the operation. The presence of mental and social problems preoperatively was associated with a postoperative Visick grade IV. Despite repeated medical therapy, and reoperation in 6 patients, 10(26%) patients still had severe pain and/or dumping at follow up. Proximal gastric vagotomy cannot be advocated in patients with uncomplicated duodenal ulcer resistant to cimetidine, and an alternative treatment is needed for these patients.

The "axial sacroiliac joint"

This article describes an iliac prominence and a sacral cavity, located extracapsularly approximately 15 mm dorsal to the angle created by the auricular facies of the sacroiliac joint. These bony structures are often covered by cartilage on one side, usually on the iliac prominence. The sacral cavity is occupied by areolar tissue, rich in adipocytes. They interface very closely, forming an extracapsular junction, which we have named the "axial sacroiliac joint". The study comprised 27 anatomical specimens, 3 of which were found to be ankylosed. Among the remaining 24, and iliac prominence was demonstrated on 22, and a sacral cavity on all. Descriptions and measurements of the sacroiliac joint, the "axial sacroiliac joint", and the spatial relationships are presented, the sacroiliac joint being the joint of reference. The study includes microscopy of the "axial sacroiliac joint".

Prophylactic treatment of classical and non-classical migraine with metoprolol--a comparison with placebo

A double-blind investigation with parallel groups was carried out in three Danish neurological clinics to evaluate the effect of metoprolol (Beloc, Betaloc, Seloken) versus placebo in migraine patients. 71 patients were included; 62 completed the study. The following parameters were used in the evaluation: frequency of headache attacks, days with migraine, severity score (days X intensity), and the consumption of pain-relieving tablets. The results of the study show that metoprolol 200 mg in Durules (a controlled release formulation) once daily is more effective regarding all evaluated parameters than placebo and that metoprolol is well tolerated.

Acupuncture treatment of chronic unilateral tinnitus--a double-blind cross-over trial

In a double-blind controlled trial the effect of traditional Chinese acupuncture versus placebo acupuncture was evaluated among 17 patients (8 females and 9 males, mean age 45.7 years) with chronic (mean disease duration 5.3 years) unilateral tinnitus. None of the patients had any treatable otological disease. All patients suffered from daily tinnitus, the intensity of which was recorded by the patients themselves every day during a period of 15 weeks. Each patient was treated by traditional Chinese acupuncture as well as placebo acupuncture following randomization (Figure 1). Each period of treatment comprised 2 treatments a week for 3 weeks. Throughout the whole investigation a period effect was recorded, insignificant in the acupuncture-placebo group, but significant in the placebo-acupuncture group (Friedman analysis of variance) (Table 4). There was no significant difference between traditional Chinese acupuncture and placebo (Wilcoxon test, P greater than 0.05, one-tailed). There was no relation between the patients' subjective statements and the results of sound balance measurements as an objective standard of tinnitus (Spearman test).