The epithelial mesenchymal transition process may contribute to the pathogenesis of amniotic band syndrome

Histological response and expression of collagen, metalloproteinases MMP-1 and MMP-9 and tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2 in fetal membranes following open intrauterine surgery: an experimental study

Objective: To characterize aspects of the repair process by evaluating the tissue collagen density, metalloproteinases and tissue inhibitor of matrix metalloproteinases in the fetal membranes following open fetal surgery for myelomeningocele (MMC).Design: Experimental.Setting: Two Brazilian hospitals in 2013-2014.Population: 30 fetal membranes collected after elective cesarean deliveries, in patients who underwent open fetal surgery for MMC intrauterine repair.Methods: Regions within and surrounding the scar area and regions distant from the surgical site were evaluated for collagen concentration and expression of MMP-1, MMP-9, TIMP-1 and TIMP-2.Results: Collagen was increased in regions of scar formation (14.4 ± 2.7%) as compared to unaffected regions (8.0 ± 1.9%) (p < .001). The mean score of MMP-9 in the area of both the scar and suture was also increased above that observed in normal regions (p < .05). Conversely, MMP-1 was reduced in the scar when compared to the normal region and the area adjacent to the scar (suture region) (p < .05). TIMP-1 was increased in the suture region compared to the normal region (p < .05) while TIMP-2 was reduced in the scar region when compared to the other two regions (p < .05). The membrane repair process was also influenced by the number of previous pregnancies and gestational age at the time of surgery.Conclusion: Reparative activity of the fetal membrane after open fetal surgery involves up-regulation of collagen production and differential involvement of MMPs and TIMPs.

A transient finding of fetal head entrapment caught in a uterine synechium or amniotic band

Background

Uterine synechia are bands of fibrous tissue that when seen on prenatal ultrasound are not felt to pose significant risk to a fetus outside of early pregnancy loss. On the contrary, amniotic bands are diagnosed when bands of amniotic tissue are found to entrap and possible amputate involved fetal parts.

Case presentation

Ultrasound imaging demonstrated a twin pregnancy affected by entrapment of twin B’s head in a uterine synechium versus an amniotic band at 11 weeks + 0 days. The entrapment persisted until the second trimester. After a review of still images and video clips with a fetal surgeon, the patient was scheduled for possible fetal surgery. Upon arrival at 16 weeks + 0 days, the entrapment was observed to have spontaneously resolved. The patient experienced preterm premature rupture of membranes at 17 weeks + 6 days, and developed chorioamnionitis at 18 weeks + 5 days. Shortly after diagnosis with chorioamnionitis, she delivered spontaneously at 18 weeks + 5 days. Postnatal hysteroscopy demonstrated uterine synechium at the uterine fundus, which was resected.

Conclusions

This is the first case of fetal head entrapment by a uterine synechium.

Histological evidence of reparative activity in chorioamniotic membrane following open fetal surgery for myelomeningocele

An increased understanding of the reparative process in fetal membrane following surgical techniques may be helpful to decrease the risks to mother and fetus and avoid adverse pregnancy outcomes. The present study discusses histological evaluation of the fetal membrane following open fetal surgery. Chorioamniotic membranes (n=10) were obtained following birth from pregnancies that underwent open fetal surgery for myelomeningocele. The collagen distribution was quantified using picrosirius-polarization method comparing the suture site with non-suture site. The differences between the collagen fiber percentages at the two sites was evaluated by the paired t-test with P<0.05. The mean gestational age of fetal surgery was 26.09±0.3 and 33.81±0.82 weeks at birth. The picrosirius red sign was more intense at the suture site, primarily associated with collagen type 1. Collagen observed in the surgical area was significantly increased (13.22±2.84%) compared with the non-surgical area (6.16±1.09%; P<0.0001). It was observed that the reparative activity at the suture site of the fetal membrane was characterized by a significant increase in collagen fibers. The findings suggest nascent collagen synthesis, tissue remodeling and repair of suture site, a mechanism likely to prevent the amniotic fluid leakage and maintain pregnancy following open fetal surgery.

Amniotic Band Syndrome With Pseudoarthrosis of Tibia and Fibula: A Case Report

Constriction of the lower limb by a congenital amniotic band has been proposed to explain the development of pseudoarthrosis of the tibia and fibula. We report a case of amniotic band syndrome in a preterm female infant with pseudoarthrosis of the tibia and fibula. She was born at 29 weeks of gestation with congenital amniotic bands and was noted to have a severely edematous left foot distal to the constricting band with rudimentary digits. The skin was pink and well perfused with palpable pulses. Radiography demonstrated pseudoarthrosis of the tibia and fibula. The limb deformities were managed with splints, positioning, and physiotherapy. She underwent Z-plasty with soft tissue release on the left lower leg on day 7 of life. At 36 weeks of postmenstrual age, a repeat radiograph showed markedly improved growth of the tibia and fibula with mature new bone formation, which avoided the need for further surgical intervention. During the follow-up period, she underwent left Syme's amputation at 18 months. At 29 months of age, the child was able to walk and run without support. The findings from our case confirm the potential for bone growth in patients with amniotic band syndrome, once the constricting band has been released. Simple release of the constriction band with Z-plasty resulted in growth of mature bone, replacing the pseudoarthrosis and, hence, the patient did not require surgical amputation. Thus, one should be cautious when deciding on surgical amputation, even in the presence of pseudoarthrosis, especially in preterm infants. Early limb-preserving surgery with release of the constricting band with an intention to salvage the limb appears appropriate.

[Complex of amniotic deformities, adhesions, mutilations: Endless debate]

Amniotic deformities, adhesions, mutilations (ADAM) complex is a broad heterogeneous spectrum of congenital anomalies. ADAM complex is characterized by constriction rings, amputation of fingers or limbs and the presence of the amniotic band. However, it may also involve craniofacial disruptions, body wall defects and internal organ abnormalities. The aim of this review is to present the results found in regard to ADAM complex from its historical background, clinical manifestations, epidemiology, etc. In particular, our attention was focused on demonstrating the varying etiopathogenesis theories of ADAM complex and their contradictions. The study was conducted using the databases of PubMed, EBSCO host, Ovid, SpringerLink, Scopus, nature.com, JAMA and ScienceDirect with the following keywords for the search: "amniotic band syndrome", "amniotic band sequence", "Streeter dysplasia", "ADAM complex". In this study we used 22 full-text articles. Patients with ADAM complex require a complete pre- and postnatal evaluation to integrate the diagnosis and to decide on timely treatment. It is important for clinicians and surgeons to possess knowledge of this entity. Further research is necessary to establish a nosological basis.