The Influence of Blood Pressure on Fetal Aortic Distensibility: An Animal Validation Study.

BACKGROUND/AIMS: Aortic distension waveforms describe the change in diameter or cross-sectional area over the cardiac cycle. We aimed to validate the association of aortic fractional area change (AFAC) with blood pressure (BP) in a fetal lamb model. METHODS: Four pregnant ewes underwent open fetal surgery under general anesthesia at 107-120 gestational days. A 4-Fr catheter was introduced into the fetal femoral artery and vein, or the carotid artery and jugular vein. The thoracic aorta was imaged using real-time ultrasound; AFAC was calculated using offline speckle tracking software. Measurements of invasive BP and AFAC were obtained simultaneously and averaged over 10 cardiac cycles. BP was increased by norepinephrine infusion and the association of aortic distensibility with BP was assessed. RESULTS: Baseline measurements were obtained from 4 lambs, and changes in aortic distensibility with increasing BP were recorded from 3 of them. A positive correlation was found between AFAC and systolic BP (r = 0.692, p = 0.001), diastolic BP (r = 0.647, p = 0.004), mean BP (r = 0.692, p = 0.001), and BP amplitude (r = 0.558, p = 0.016) controlled for heart rate. No association was found between BP and maximum or minimum aortic area. CONCLUSION: AFAC provides a quantifiable measure of aortic distensibility and correlates with systolic BP, diastolic BP, mean BP, and BP amplitude in a fetal lamb model.

Cryopreserved human umbilical cord versus biocellulose film for prenatal spina bifida repair in a physiologic rat model.

BACKGROUND: Prenatal spina bifida (SB) repair with a regenerative patch may improve neurological outcomes by decreasing inflammatory scarring. OBJECTIVE: This study aims to compare cryopreserved human umbilical cord (HUC) and biocellulose film (BCF) patches sutured over SB lesions for regeneration of native cells and inflammatory response. STUDY DESIGN: Sprague-Dawley rats were gavaged with retinoic acid (RA) on embryonic day 10 to induce SB. Hysterotomy was performed on embryonic day 20 and on HUC or BCF patches sutured over the defect. Pups were harvested 30 to 34 h later, and hematoxylin and eosin staining and Trichrome staining assessed basic cellular migration. Immunohistochemistry demonstrated the exact nature of the cellular migration. Patches and surrounding exudates were evaluated with microscopy and cells quantified. RESULTS: Histology showed cellular migration with all HUC patches compared with none with BCF patches. Epithelial cells were noted migrating over the dorsal HUC surface, astrocytes were noted along the HUC surface adjacent to the lesion, and endothelial cells were noted within the HUC. HUC patches showed minimal inflammatory cells. Exudates surrounding the HUC patches had fewer inflammatory cells than exudates around BCF patches. CONCLUSION: HUC promotes cellular migration of native cells with minimal inflammatory response compared with BCF. HUC may be the superior patch material for prenatal SB repair. © 2017 John Wiley & Sons, Ltd.

Anti-Vel alloimmunization and severe hemolytic disease of the fetus and newborn.

CONCLUSIONS: Only rare cases of anti-Vel-associated mild-to-moderate hemolytic disease of the fetus and newborn have been previously reported. No case of fetal anemia requiring prenatal therapy has been noted to date. We report such a case recently encountered at our Fetal Center. Strategies are discussed for managing pregnancy complicated with alloimmunization to an antibody to a high-prevalence antigen, including sources of red blood cells for intrauterine transfusions.

Neurological Outcomes after Human Umbilical Cord Patch for In Utero Spina Bifida Repair in a Sheep Model.

OBJECTIVES: The objective of our study was to test the hypothesis that in utero repair of surgically created spina bifida in a sheep model using cryopreserved human umbilical cord (HUC) patch improves neurological outcome. METHODS: Spina bifida with myelotomy was surgically created in timed pregnant ewes at gestational day (GD) 75. The fetuses were randomly assigned to unrepaired versus HUC and treated at GD 95 and then delivered at GD 140. Neurological evaluation was performed using the Texas Spinal Cord Injury Scale (TSCIS), bladder control using ultrasound, and the hindbrain herniation. RESULTS: Three lambs without the spina bifida creation served as controls. There were four lambs with spina bifida: two were unrepaired and two underwent HUC repair. The control lambs had normal function. Both unrepaired lambs had nonhealed skin lesions with leakage of cerebrospinal fluid, a 0/20 TSCIS score, no bladder control, and the hindbrain herniation. In contrast, both HUC lambs had a completely healed skin defect and survived to day 2 of life, a 3/20 and 4/20 TSCIS score (nociception), partial bladder control, and normal hindbrain anatomy. CONCLUSIONS: Cryopreserved HUC patch appears to improve survival and neurological outcome in this severe form of the ovine model of spina bifida.