Preterm newborns undergoing selective correction surgery of the patent ductus arteriosus: is there still space for these procedures?

Introduction: The ductus arteriosus is a small fetal structure that connects two large arteries (aorta and pulmonary) but becomes pathological when it is maintained after birth. Morbidities associated with persistent patent ductus arteriosus (PDA) may lead to the conclusion that the best approach is early surgical treatment. However, there is evidence that expectant (more selective) surgical management may reduce the chances of unnecessary surgeries and their risks. Objective: To analyze the clinical and surgical profile of preterm newborns submitted to selective correction surgery of the patent ductus arteriosus. Method: This paper contemplates a series of cases, in which all patients submitted to the surgical treatment of PDA in preterm infants were described retrospectively (2009-2016), through the analysis of medical records of the Santa Marcelina Hospital, SP-Brazil. Results: During this period, there were 13 cases of premature infants who underwent selective surgical correction of PDA. Gestational age was 26.92 weeks, maternal age ranged from 15 to 44, birth weight varied between 650 and 1500g, mostly women (61.54%). The diameter of the ductus arteriosus ranged from 1.7 to 4.1 mm, four patients had complex congenital heart disease (30.77%). The median courses of indomethacin were 1.77, congestive heart failure was shown in 11 patients (84.62%), the median age at surgery was 27.69 days and the median duration of orotracheal intubation was 22.62 days. The weight of the newborns at the time of the surgical act varied between 900 and 1820g. The postoperative complications were mostly infectious, with nine patients with bronchopneumonia (69.23%), one patient had pneumothorax. Sepsis occurred in two cases (15.35%) that died due to the same complication (15.35%). Conclusion: All preterm newborns who underwent surgery had birth weight less than 1500g. The median arterial canal was 3.05 mm in diameter. The median gestational age was 26.92 weeks and 62% of the cases were female. The most frequent surgical technique was the triple clipping, there was no bleeding or reoperation in this series of cases. ge at surgery was 27.69 days and the median duration of orotracheal intubation was 22.62 days. The weight of the newborns at the time of the surgical act varied between 900 and 1820g. The postoperative complications were mostly infectious, with nine patients with bronchopneumonia (69.23%), one patient had pneumothorax. Sepsis occurred in two cases (15.35%) that died due to the same complication (15.35%). Conclusion: All preterm newborns who underwent surgery had birth weight less than 1500g. The median arterial canal was 3.05 mm in diameter. The median gestational age was 26.92 weeks and 62% of the cases were female. The most frequent surgical technique was the triple clipping, there was no bleeding or reoperation in this series of cases.

Developmental changes in hemodynamics of uterine artery, utero- and umbilicoplacental, and vitelline circulations in mouse throughout gestation

In human pregnancy, abnormal placental hemodynamics likely contribute to the etiology of early-onset preeclampsia and fetal intrauterine growth restriction. The mouse is increasingly being deployed to study normal and abnormal mammalian placental development, yet the placental hemodynamics in normal pregnancy in mice is currently unknown. We used ultrasound biomicroscopy to noninvasively image and record Doppler blood velocity waveforms from the maternal and embryonic placental circulations in mice throughout gestation. In the uterine artery, peak systolic velocity (PSV) increased significantly from 23 ± 2 (SE) to 59 ± 3 cm/s, and end-diastolic velocity (EDV) increased from 7 ± 1 to 28 ± 2 cm/s in nonpregnant versus full-term females so that the uterine arterial resistance index (RI) decreased from 0.70 ± 0.02 to 0.53 ± 0.02. Velocities in the maternal arterial canal in the placenta were low and nearly steady and increased from 0.9 ± 0.03 cm/s at embryonic day 10.5 (E10.5) to 2.4 ± 0.07 cm/s at E18.5. PSV in the umbilical artery increased steadily from 0.8 ± 0.1 cm/s at E8.5 to 15 ± 0.6 cm/s at E18.5, whereas PSV in the vitelline artery increased from 0.6 ± 0.1 cm/s at E8.5 to 4 ± 0.2 cm/s at E13.5 and then remained stable to term. In the umbilical artery, the EDV detection rate was 0% at ≤E14.5 and 94% at E18.5, and the RI decreased from 1 to 0.82 ± 0.01 during this interval. We conclude that ultrasound biomicroscopy can be used to monitor placental hemodynamics during pregnancy in mice. These results provide novel information concerning the development of the vitelline and placental circulations in mice and reveal strong similarities in placental hemodynamics between mice and humans.

Invasion of the Placenta during Murine Listeriosis

ABSTRACT Feto-placental infections due to Listeria monocytogenes represent a major threat during pregnancy, and the underlying mechanisms of placental invasion remain poorly understood. Here we used a murine model of listeriosis (pregnant mice, infected at day 14 of gestation) to investigate how this pathogen invades and grows within the placenta to ultimately infect the fetus. When L. monocytogenes is injected intravenously, the invasion of the placenta occurs early after the initial bacteremia, allowing the placental growth of the bacteria, which is an absolute requirement for vertical transmission to the fetus. Kinetically, bacteria first target the cells lining the central arterial canal of the placenta, which stain positively with cytokeratin, demonstrating their fetal trophoblast origin. Bacteria then disseminate rapidly to the other trophoblastic structures, like syncytiotrophoblast cells lining the villous core in the labyrinthine zone of placenta. Additionally, we found that an inflammatory reaction predominantly constituted of polymorphonuclear cells occurs in the villous placenta and participates in the control of infection. Altogether, our results suggest that the infection of murine placenta is dependent, at the early phase, on circulating bacteria and their interaction with endovascular trophoblastic cells. Subsequently, the bacteria spread to the other trophoblastic cells before crossing the placental barrier.

XII. Evidence of a large extinct monotreme (Echidna Ramsayi, Ow.) from the Wellington Breccia Cave, New South Wales

Amongst the detached bones and fragmentary evidences of Mammals from the abovenamed locality, submitted to me by Edward P. Ramsey, Esq., F. L. S., who thence obtained them, was a humerus sufficiently complete to yield the following characters. It was of great breadth in proportion to its length, and, through the unusual size and direction of the processes and ridges for muscular attachments, seemed as if the shaft of the bone had been twisted half-way round on its axis. The head, or proximal articular surface (Plate 14, fig. 1, a , and fig. 3), is a transversely elongated convexity, of a narrow ovate shape, with the broader end toward the ectotuberosity, b —the direction of such joint being at right angles to that of the feline humerus, in which, as in Thylacoleo , the antero-posterior or then-anconal diameter prevails. The non-articular portions of this end of the bone extend for equal distances to the ento- c - and ecto- b -tuberosities. From the latter is continued the “deltoid” or “anterior bicipital” ridge, f , from which, after its course of more than one-third the length of the shaft, it is continued by a lower ridge along the thenal aspect to be lost in the bony bridge overarching the neur-arterial canal, k , v . From the ento-tuberosity, c , is continued the “teretial” or “posterior tricipital” ridge, along the radial border of the humeral shaft to its termination in a special process —the "tricipital,” d . Moreover, both ento- and ecto-tuberosities are connected together by a low curved ridge or rising which bounds a small portion of the palmar surface of the shaft immediately below the head of the humerus. From the bridge, k , is continued a narrow ridge to the ent-epicondylar process, i . The distal end of the humerus is continued, ridge-like, from i to a process j midway between the epicondyles, h and i , but bounding the ulnar trochlea, u . A notch below the outlet of the neur-arterial canal, k , indicates the ulnar trochlea and divides the process, j , from the articular tuberosity or condyle, l , for the head of the radius. A very small proportion of this condyle is continued upon the anconal surface of the humerus (Plate 14, fig 2); the convexity there changes to a concavity, u , for the ulna, and from e is continued the ectepicondyle, h , as a well-marked outstanding process.