Search PubMed⌕ Search

Biomedical subjects

M Hansmann

Publications and source records attributed to M Hansmann.

At least 19 recordsLinked to original sources
PubMed2006

The syndrome of right isomerism -- prenatal diagnosis and outcome.

OBJECTIVE: To evaluate the accuracy of the prenatal diagnosis of right isomerism and to assess possible diagnostic and prognostic markers. METHODS: Retrospective review of all cases of right isomerism identified between 1989 and 2003 in two tertiary referral centres in Germany. RESULTS: Among 21 foetuses, 16 had a correct prenatal diagnosis of right isomerism. 19 showed different types of viscerocardiac heterotaxy, 12 of them in combination with juxtaposition of vena cava inferior and aorta. 20 had cardiac defects, with a high prevalence of atrioventricular septal defect (CAVSD) (62 %), right outflow tract obstruction (48 %), anomalous pulmonary venous return (33 %) and double outlet right ventricle (29 %). 4 out of 6 cases with total anomalous pulmonary venous return were overseen on prenatal ultrasound. Only 6 children survived. The highest loss occurred in the neonatal period. Two out of 6 survivors underwent single ventricle palliation, while another two had a biventricular repair. One child is awaiting mitral valve replacement. The remaining case has no cardiac defect and lives with supraventricular re-entry tachycardia. Only the presence of CAVSD was significantly correlated with non-survival (p < 0.05). CONCLUSIONS: The prenatal diagnosis of right isomerism remains a difficult task. Important sonographic markers are viscerocardiac heterotaxy, complex cardiac malformations and juxtaposition of vena cava inferior and aorta. Special attention has to be paid to the pattern of pulmonary venous drainage, as it is often misdiagnosed. The mortality in neonates is high, especially in the presence of CAVSD. Survivors suffer from significant morbidity.

Adolescent↗
PubMed2006

Bulk electronic structure of metals resolved with scanning tunneling microscopy.

We demonstrate that bulk band structure can have a strong influence in scanning tunneling microscopy measurements by resolving electronic interference patterns associated with scattering phenomena of bulk states at a metal surface and reconstructing the bulk band topology. Our data reveal that bulk information can be detected because states at the edge of the surface-projected bulk band have a predominant role on the scattering patterns. With the aid of density functional calculations, we associate this effect with an intrinsic increase in the projected density of states of edge states. This enhancement is characteristic of the three-dimensional bulk band curvature, a phenomenon analog to a van Hove singularity.

Journal Article↗
PubMed2006

Prenatal diagnosis of persistent left superior vena cava and its associated congenital anomalies.

OBJECTIVE: To evaluate the associated conditions and the outcome of persistent left superior vena cava (PLSVC) detected in fetal life. METHODS: This was a retrospective review of all cases of PLSVC detected prenatally between 1998 and 2004 in two tertiary referral centers in Germany. Patient charts, ultrasound video recordings and still frames of all cases were reviewed for associated conditions and outcome. RESULTS: Eighty-two cases of PLSVC were detected in the study period. Thirty-seven cases (45%) were associated with heterotaxy syndromes, 19 (23%) with isolated cardiac malformations, seven (9%) with aneuploidy, six (7%) with complex malformation syndromes and six (7%) with isolated extracardiac malformations. Seven cases (9%) had no associated condition. Eighty-three percent of the fetuses in this series had associated cardiac malformations; the most frequent cardiac malformations in those with heterotaxy syndromes were complete atrioventricular septal defect (75%) and right outflow tract obstruction (58%). After exclusion of cases with heterotaxy, most congenital heart defects were ventricular septal defects (41%) and coarctation (34%). The outcome of PLSVC was determined solely by the associated conditions. After exclusion of terminated cases, heterotaxy syndromes as well as complete atrioventricular septal defects were associated significantly with perinatal and infant death. In contrast, all cases with isolated PLSVC or associated correctable extracardiac malformations survived and were doing well at the time of writing. CONCLUSIONS: PLSVC detected in fetal life has to be followed by a meticulous inspection of the fetal anatomy as it is frequently associated with heterotaxy syndromes, other cardiac/non-cardiac malformations and aneuploidy that determine the outcome. Isolated PLSVC is a benign vascular anomaly and may not affect the outcome.

Chromosome Aberrations↗
PubMed2006

Absence of ductus venosus-importance of umbilical venous drainage site.

OBJECTIVE: To evaluate the conditions associated with absent ductus venosus (ADV) diagnosed by prenatal ultrasonography. METHODS: Retrospective review of 23 cases with ADV diagnosed in two tertiary referral centers with a general screening policy concerning Doppler assessment of the ductus venosus. The results are discussed together with 63 cases from a review of the literature. RESULTS: In 19 fetuses the umbilical vein connected to the portal sinus, while the remaining four fetuses had extrahepatic umbilical venous drainage. Associated anomalies were present in 15 out of 23 fetuses: complex malformation syndromes (n = 6), chromosomal anomalies (n = 4), isolated cardiac defects (n = 4) and isolated extracardiac anomalies (n = 1). Eight fetuses had either no associated anomalies or minor anomalies. Hydropic changes were present in 12 of the 23 fetuses. In common with the reviewed cases, the presence of cardiac malformations, complex non-chromosomal malformation syndromes and hydrops was significantly associated with intrauterine or postnatal death while the type of umbilical venous drainage was not significantly different between survivors and non-survivors. However, among fetuses with no or minor associated anomalies the outcome was significantly better in the group without liver bypass. CONCLUSIONS: ADV is significantly associated with fetal cardiac and extracardiac anomalies, aneuploidies and hydrops. Fetuses with liver bypass have an additional risk of developing congestive heart failure that significantly affects outcome, even if the fetal cardiovascular anatomy is otherwise normal. ADV without liver bypass seems to have a more favorable prognosis if it is not associated with other malformations.

Aneuploidy↗
PubMed2005

Atrioventricular block detected in fetal life: associated anomalies and potential prognostic markers.

OBJECTIVES: To assess the spectrum of anomalies associated with fetal heart block and to identify possible prognostic markers. METHODS: Retrospective review of all cases of second- or third-degree heart block identified in two tertiary referral centers in Germany (Bonn and Lübeck) and one in the USA (Baltimore). RESULTS: Sixty fetuses with heart block were identified in the study period. Thirty-two had complex cardiac malformations, 31 of them associated with left isomerism. The outcomes of these fetuses were 22 terminations of pregnancy (TOP), three intrauterine fetal deaths (IUFD), three neonatal deaths (NND), two childhood deaths (CD) and there were two survivors. In 20 cases without complex cardiac malformations maternal antinuclear-antibodies were detected. Their outcomes were 2 TOP, 1 IUFD, 1 NND and 16 survived. The remaining eight cases had neither complex cardiac malformations nor associated maternal antibodies. Their outcomes were 1 TOP, 2 IUFD, 2 NND and 3 survived. After exclusion of terminated cases, hydrops as well as the presence of cardiac defects was significantly associated with non-survival (P < 0.01). The cardiothoracic circumference ratio was significantly higher in hydropic fetuses and significantly negatively correlated with survival in immune-mediated cases (P < 0.01). Atrial and ventricular frequencies and their evolution did not accurately predict fetal or neonatal outcome. Sympathomimetic treatment in seven cases was not associated with favorable fetal outcome in cases of hydrops or cardiac malformations. CONCLUSIONS: The most important marker predicting adverse outcome in cases of heart block is fetal hydrops, followed by the association with complex cardiac malformations. Cases without cardiac malformations have a significantly better prognosis, especially in the absence of severe cardiomegaly.

Adult↗
PubMed2005

Fetal echocardiographic evaluation of atrial morphology and the prediction of laterality in cases of heterotaxy syndromes.

OBJECTIVE: To evaluate whether abnormal atrial morphology, which is well recognized in autopsy series, is detectable by fetal echocardiographic examination of the four-chamber view, and can therefore be utilized to differentiate left from right isomerism in heterotaxy syndromes. METHODS: This study was a retrospective review of 30 cases with prenatally diagnosed heterotaxy syndromes. Ultrasound video recordings and still images were reviewed with respect to atrial morphology in the four-chamber view. In 25 cases the morphology of both atria was sufficiently well visualized on the recordings to be evaluated and only these were included in the study. RESULTS: Two types of atrial morphology were distinguished in our cohort: a sickle-shape with the tip pointing laterally and apically, and a blunt shape resembling the usual atrial appearance in the four-chamber view. Nineteen out of the 25 cases (76%) presented with isomerism of the atria in the four-chamber view. Thirteen had bilateral sickle-shaped atrial morphology, all associated with left isomerism. Six had bilateral blunt-shaped atrial morphology, all associated with right isomerism. The atria of the remaining six cases were not isomeric, the right atrium being sickle-shaped and the left blunt-shaped. Five of the latter cases were associated with left and one with right isomerism. CONCLUSIONS: The majority of prenatally diagnosed heterotaxy syndromes seem to present with isomeric atrial morphology in the four-chamber view. In these cases a differentiation between left and right isomerism can be based on the two distinct types of atrial morphology. This may further enhance the prenatal differentiation of these syndromes.

Chi-Square Distribution↗
PubMed2004

Role of spin in quasiparticle interference.

Quasiparticle interference patterns measured by scanning tunneling microscopy can be used to study the local electronic structure of metal surfaces and high-temperature superconductors. Here, we show that even in nonmagnetic systems the spin of the quasiparticles can have a profound effect on the interference patterns. On Bi(110), where the surface state bands are not spin degenerate, the patterns are not related to the dispersion of the electronic states in a simple way. In fact, the features which are expected for the spin-independent situation are absent and the observed interference patterns can be interpreted only by taking spin-conserving scattering events into account.

Journal Article↗
PubMed2004

A new formula for calculating weight in the fetus of < or = 1600 g.

OBJECTIVE: To develop and test a new formula for estimating weight in the fetus of < or = 1600 g. METHODS: A formula for sonographic estimation of fetal weight was produced retrospectively from 84 singleton fetuses with a birth weight of < or = 1600 g, examined sonographically within 1 week before delivery. Exclusion criteria were multiple pregnancy, intrauterine death and major structural or chromosomal anomalies. The new formula was then compared prospectively in an evaluation group of fetuses (n = 87) with six currently available equations for estimating weight in the preterm fetus. RESULTS: Stepwise regression analysis with gestational age (in days) and fetal biometric parameters was employed to yield the best-fit formula for predicting fetal weight at birth. The new formula (estimated fetal weight = 5381.193 + 150.324 x head circumference + 2.069 x femur length3 + 0.0232 x abdominal circumference3-6235.478 x log(head circumference)) proved to be superior to established equations. The lowest mean +/- SD absolute error was 66.2 +/- 59 g and the lowest mean absolute percentage error was 7.1 +/- 5.9% SD when studied prospectively in the evaluation group. With the new formula, 48.3% of estimates fell within +/-5% of the actual weight at birth, 73.6% fell within +/-10%, 90.8% fell within +/-15% and 95.4% fell within +/-20%. CONCLUSION: Our new formula is relatively easy to use and needs no adjustment to weight centiles or to fetal lie. It allows reliable weight estimation in the fetus < or = 1600 g.

Body Weight↗
PubMed2004

Targeted first-trimester prenatal diagnosis before fetal reduction in triplet gestations and subsequent outcome.

OBJECTIVE: To assess the feasibility of targeted first-trimester ultrasound evaluation in triplet gestations and to report the outcome in reduced and expectantly managed triplets. METHODS: This was a retrospective analysis of 127 triplets at 11-14 weeks with targeted ultrasound examination including nuchal translucency (NT) screening. RESULTS: One or more abnormal findings were observed in 33 of 381 fetuses (8.7%), including increased NT (n = 18), malformations (n = 4), aneuploidy (n = 3), relative intrauterine growth restriction (n = 2) or spontaneous demise (n = 13). Of 63 patients (49%) who chose reduction, selective termination due to abnormal findings was performed in 13 fetuses. The rates of complete abortion <24 weeks were 9.8% and 3.2% for those with expectant management and fetal reduction, respectively. Expectantly managed triplets delivered significantly earlier (31.1 +/- 3.8 vs. 35.6 +/- 3.3 weeks) (P < 0.01) with a lower mean birth weight (1483 +/- 552 g vs. 2305 +/- 557 g) (P < 0.01) and a lower number of liveborn fetuses (85.6% vs. 97.4%) (P < 0.01) than those reduced. CONCLUSION: Targeted first-trimester ultrasound is feasible and reliable in triplet gestations and should be an integral part of the counseling process. It results in more accurate selection for those who consider fetal reduction. Our data further support fetal reduction as a valuable strategy to improve perinatal outcome in triplet pregnancies.

Adult↗
PubMed2004

Sex-specific fetal weight prediction by ultrasound.

OBJECTIVE: To improve sonographic birth-weight prediction by developing fetal gender-specific formulae. METHODS: This was a retrospective cross-sectional study. Two gender-specific formulae were produced from the data of 527 patients and the data of a further 349 patients were used to evaluate the formulae. Inclusion criteria were a singleton live fetus, gestational age above 25 weeks, birth weight between 1000 g and 4500 g and fetal biometry within 8 days of delivery. Data retrieval was specifically for the purpose of this study. RESULTS: To yield the best-fit weight formula for each fetal gender we employed step-wise regression analysis based on fractional polynomials with the biometric parameters biparietal diameter (BPD), head circumference (HC), transverse abdominal diameter (TAD), abdominal circumference (AC) and femur length (FL): estimated fetal weight for girls (g) = - 4035.275 + 1.143 x BPD3 + 1159.878 x AC1/2 + 10.079 x FL3 - 81.277 x FL2 [in cm]; estimated fetal weight for boys (g) = 43576.579 + 1913.853 x log10BPD + 0.01323 x HC3 + 55.532 x AC2 - 13602.664 x AC1/2 - 0.721 x AC3 + 2.31 x FL3 [in cm]. These formulae showed superior results compared with those of conventional weight formulae. CONCLUSION: Gender-related fetal weight calculation allows optimized prediction of fetal weight at birth.

Adolescent↗
PubMed2004

Congenital chylothorax: lymphopenia and high risk of neonatal infections.

AIM: To describe the clinical course of patients with congenital chylothorax focusing on infectious complications. Congenital chylothorax is a common manifestation of non-immune hydrops fetalis (NIHF). The drainage of chyle leads to loss of cellular and plasmatic factors that influence the patient's immune response and increase the risk of infections. METHODS: In a retrospective analysis of 24 preterm infants with NIHF treated between 1998 and 2002, congenital chylothorax was diagnosed in 7 patients. RESULTS: All 7 patients were treated conservatively with pleural drainage over a median period of 22 d (range 10-36 d). Lymphopenia was found in all patients (median of minimal lymphocyte counts 285/microl, range 80-770). The nadir was on day 5 (2-6 d). Lymphopenia lasted for 12 d median (range 4-39 d) and was significantly correlated with the duration of lymph drainage (p = 0.001). Cell-surface analysis of peripheral blood lymphocytes was performed in two patients. Both patients had a decreased number of total T cells. Four out of seven (57%) patients developed nosocomial infections. This incidence of nosocomial infections in patients with congenital chylothorax is about three times higher than that in other neonatal patients. None of the children suffered from fungal or viral infection. Although there was a very high incidence of infections, no correlation between lymphopenia and the occurrence of infections could be shown. CONCLUSION: Drainage of congenital chylothorax results in the loss of lymphocytes and bears a high risk of infections.

Bacterial Infections↗
PubMed2002

[Significance of prenatal diagnosis of lip-jaw-palatal clefts].

UNLABELLED: AIMS AND PATIENTS: Visualization of sonographic anatomy of the fetal face has acquired special importance, as conspicuous features in the phenotype facilitate the diagnosis of syndrome-like or chromosomally induced clinical conditions. Between 1990 and 1999, an orofacial cleft was diagnosed sonographically in 70 fetuses at the Clinic for Prenatal Diagnosis and Therapy of Bonn University Hospital. The aim of the study was to investigate whether the type of cleft correlates with the prevalence of associated anomalies or with karyotyping after amniocentesis. The types of associated anomalies and the neonatal outcome of these 70 fetuses were also reexamined. RESULTS: We found a clearly positive correlation with the type of cleft, both for the associated anomalies and for the karyotype. The size of the cleft was much smaller with normal karyotypes than in the case of fetuses with trisomy 18. The trisomy 13 fetuses displayed the most pronounced clefts. None of the fetuses with an isolated lip cleft had an associated anomaly; all were born alive and could be treated surgically. In contrast, all the fetuses with a median cleft had severe associated anomalies that were incompatible with life. Associated anomalies occur more frequently with bilateral cleft lip and palate than with unilateral clefts. The fetuses with a unilateral cleft had a higher survival rate than those with a bilateral cleft. The most common associated anomaly in cleft fetuses is located in the region of the central nervous system. DISCUSSION: Early sonographic information on cleft formation in combination with the karyotype can give rise to differentiated obstetric measures up to the point of termination of pregnancy in the event of an infaust prognosis.

Abnormalities, Multiple↗
PubMed2002

Venous Doppler velocimetry in the surveillance of severely compromised fetuses.

OBJECTIVE: To investigate whether venous Doppler velocimetric signs of cardiac decompensation might predict fetal demise in severely compromised fetuses. MATERIAL AND METHODS: This was a prospective study involving 154 growth-restricted fetuses, 37 of which were found to have reversed flow in the umbilical artery (BFC III). Doppler velocimetry of the right hepatic vein and ductus venosus were investigated serially and the presence of umbilical venous pulsations also registered. Only the final examination prior to birth or fetal demise was accepted for analysis and related to obstetric outcome defined as gestational age at birth, birth weight and perinatal mortality. In cases of BFC III the venous velocimetry of 15 nonsurviving fetuses was compared to that of the 22 survivors. RESULTS: There was a significant correlation between venous blood velocity and placental vascular resistance. In the right hepatic vein there was a significant decrease in peak systolic and end-systolic velocities and an increase of maximum velocity during atrial contraction and pulsatility (P < 0.05). A decrease of all velocities and increase of pulsatility were noted in the ductus venosus (P < 0.05). A reversed flow in the ductus venosus was found in 9/37 fetuses and double umbilical venous pulsations in 16/37 fetuses. However, the hepatic vein seemed to be a better predictor of impending mortality than the ductus venosus. Changes in diastolic venous blood velocity and a double pulsation in the umbilical vein were closely related to perinatal mortality, although these parameters did not provide a useful threshold to optimize the timing of delivery. CONCLUSION: Diastolic venous velocimetry changes significantly in severely compromised fetuses. These changes might be of great clinical value in deciding on the timing of delivery to minimize damage to the fetus and newborn.

Blood Flow Velocity↗
PubMed2002

Neurodevelopmental outcome after intrauterine red cell transfusion for parvovirus B19-induced fetal hydrops.

OBJECTIVE: To assess long term neurodevelopmental outcome of children after intrauterine intravascular red cell transfusion (JUT) for Parvovirus B19-induced fetal hydrops. DESIGN: Data of study children were investigated retrospectively. Neurodevelopmental evaluation was performed by appropriate standard tests (Griffiths, Snijders-Oomen, Kaufmann Assessment Battery for Children tests). SETTING: Tertiary care university teaching hospital. SAMPLE: Twenty children who had Parvovirus-induced fetal hydrops and intrauterine transfusion of packed red blood cells (IUT). METHODS: Retrospective chart analysis and standard neurodevelopmental testing. MAIN OUTCOME MEASURES: Developmental quotient (DQ) and intelligence quotient (IQ) according to the age at testing. RESULTS: Twenty survivors of Parvovirus B19-induced fetal hydrops successfully treated by IUT were followed until 13 months to nine years of age. On clinical follow up, no neurologic sequelae were evident. Neurodevelopmental scores of all children ranged within two standard deviations of a normal population (median 101, range 86-116) and exceeded one standard deviation in three children. There was no significant neurodevelopmental delay. CONCLUSION: Children having survived successful IUT for Parvovirus B19-induced fetal anaemia and hydrops have a good neurodevelopmental prognosis. Our results support the use of IUT for correction of Parvovirus B19-induced fetal anaemia and subsequent hydrops.

Blood Transfusion, Intrauterine↗