Alexander Weichert

Dr. Alexander Weichert

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2019 in American Journal of Obstetrics and Gynecology
Verified
Journal Article
Closed access
SCSally L. Collins
Sally L. Collins
BABahrin Alemdar
Bahrin Alemdar
HBHeleen J. van Beekhuizen
Heleen J. van Beekhuizen
CBCharline Bertholdt
Charline Bertholdt
TBThorsten Braun
Thorsten Braun
FCFrederic Chantraine
Frederic Chantraine

1 February 2021 in Acta Obstetricia et Gynecologica Scandinavica
Verified
Journal Article
Open access
PDF file
ASAlexander Schwickert
Alexander Schwickert
HBHeleen J. Van Beekhuizen
Heleen J. Van Beekhuizen
CBCharline Bertholdt
Charline Bertholdt
KFKarin A. Fox
Karin A. Fox
GKGilles Kayem
Gilles Kayem
T(the International Society for Placenta Accreta Spectrum (IS‐PAS)
the International Society for Placenta Accreta Spectrum (IS‐PAS)
Introduction: Placenta accreta spectrum (PAS) carries a high burden of adverse maternal outcomes, especially significant blood loss, which can be life‐threatening. Different management strategies have been proposed but the association of clinical risk factors and surgical management options during cesarean delivery with high blood loss is not clear.Material and methods: In this international multicenter study, 338 women with PAS undergoing cesarean delivery were included. Fourteen European and one non‐European center (USA) provided cases treated retrospectively between 2008 and 2014 and prospectively from 2014 to 2019. Peripartum blood loss was estimated visually and/or by weighing and measuring of volume. Participants were grouped based on blood loss above or below the 75th percentile (>3500 ml) and the 90th percentile (>5500 ml).Results: Placenta percreta was found in 58% of cases. Median blood loss was 2000 ml (range: 150‐20 000 ml). Unplanned hysterectomy was associated with an increased risk of blood loss >3500 ml when compared with planned hysterectomy (adjusted OR [aOR] 3.7 [1.5‐9.4], p = 0.01). Focal resection was associated with blood loss comparable to that of planned hysterectomy (crude OR 0.7 [0.2–2.1], p = 0.49). Blood loss >3500 ml was less common in patients undergoing successful conservative management (placenta left in situ, aOR 0.1 [0.0–0.6], p = 0.02) but was more common in patients who required delayed hysterectomy (aOR 6.5 [1.7–24.4], p = 0.001). Arterial occlusion methods (uterine or iliac artery ligation, embolization or intravascular balloons), application of uterotonic medication or tranexamic acid showed no significant effect on blood loss >3500 ml. Patients delivered by surgeons without experience in PAS were more likely to experience blood loss >3500 ml (aOR 3.0 [1.4–6.4], p = 0.01).Conclusions: In pregnant women with PAS, the likelihood of blood loss >3500 ml was reduced in planned vs unplanned cesarean delivery, and when the surgery was performed by a specialist experienced in the management of PAS. This reinforces the necessity of delivery by an expert team. Conservative management was also associated with less blood loss, but only if successful. Therefore, careful patient selection is of great importance. Our study showed no consistent benefit of other adjunct measures such as arterial occlusion techniques, uterotonics or tranexamic acid.

11 April 2006 in Clinical Science
Verified
Journal Article
Closed access
JWJames L. Williams
James L. Williams
AWAlexander Weichert
Alexander Weichert
AZAndreas Zakrzewicz
Andreas Zakrzewicz
LSLuis Da Silva-Azevedo
Luis Da Silva-Azevedo
APAxel R. Pries
Axel R. Pries
Stuart EggintonStuart Egginton
Stuart Egginton
In adult skeletal muscle, abluminal sprouting or longitudinal splitting of capillaries can be initiated separately by muscle overload and elevated microcirculation shear stress respectively. In the present study, gene and protein expression patterns associated with the different forms of angiogenesis were examined using a targeted gene array (Superarray), validated by quantitative RT (reverse transcription)-PCR and immunoblots. Sprouting angiogenesis induced large changes in expression levels in genes associated with extracellular matrix remodelling, such as MMP-2 (matrix metalloproteinase-2), TIMP (tissue inhibitor of metalloproteinases), SPARC (secreted protein, acidic and rich in cysteine) and thrombospondin. Changes in neuropilin, midkine and restin levels, which may underpin changes in endothelial morphology, were seen during splitting angiogenesis. Up-regulation of VEGF (vascular endothelial growth factor), Flk-1, angiopoietin-2 and PECAM-1 (platelet/endothelial cell adhesion molecule-1) was seen in both forms of angiogenesis, representing a common angiogenic response of endothelial cells. In conclusion, the present study demonstrates that general angiogenic signals from growth factors can be influenced by the local microenvironment resulting in differing forms of capillary growth to produce a co-ordinated expansion of the vascular bed.

16 June 2016 in Acta Physiologica
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Journal Article
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MBMarius Reto Bigler
Marius Reto Bigler
DKDespina Koutsantonis
Despina Koutsantonis
AOAdolfo Odriozola
Adolfo Odriozola
SHSebastian Halm
Sebastian Halm
STStefan A. Tschanz
Stefan A. Tschanz
Oliver BaumOliver Baum
Oliver Baum

7 October 2016 in American Journal of Medical Genetics Part A
Verified
Journal Article
Closed access
PDF file
FAFranz Alisch
Franz Alisch
AWAlexander Weichert
Alexander Weichert
KKKarim Kalache
Karim Kalache
VPViola Paradiso
Viola Paradiso
ALAnn Carolin Longardt
Ann Carolin Longardt
DHDenise Horn
Denise Horn

19 August 2017 in Journal of Perinatal Medicine
Verified
Journal Article
Closed access
PDF file
VKVerena Kiver
Verena Kiver
VBVinzenz Boos
Vinzenz Boos
ATAnke Thomas
Anke Thomas
WHWolfgang Henrich
Wolfgang Henrich
AWAlexander Weichert
Alexander Weichert
Objective: A current descriptive assessment of perinatal outcomes in pregnancies complicated by previable preterm premature rupture of membranes (pPPROM) at <24 weeks of gestation, after expectant treatment. Study design: Maternal and short-term neonatal data were collected for patients with pPPROM. Results: Seventy-three patients with 93 fetuses were hospitalized with pPPROM at 15–24 weeks’ gestation. Among these patients, 27.4% (n=20) chose pregnancy termination, 27.4% (n=20) miscarried and 45.2% (n=33) proceeded to live births. After a median latency period of 38 days, ranging from 1 to 126 days, 24 singletons and 20 multiples were live-born, of whom 79.5% (n=35) survived the perinatal period. The main neonatal sequelae were pulmonary hypoplasia (29.5%; n=13), connatal infection (56.8%; n=25), intraventricular hemorrhage (25%; n=11; resulting in five neonatal deaths) and Potter’s syndrome (15.9%; n=7). Nine newborns died, within an average of 2.8 days (range, 1–10 days). The overall neonatal survival rate was 51.5% – including miscarriages but not elective terminations. The intact survival rate was 45.5% of all live-born neonates. Conclusions: Even with limited treatment options, overall neonatal survival is increasing. However, neonatal mortality and morbidity rates remain high. The gestational age at membrane rupture does not predict neonatal outcome.