Minimally Invasive Precise Application of Bioadhesives to Prevent IPPROM on a Pregnant Sheep Model.

INTRODUCTION: Iatrogenic preterm premature rupture of the membrane remains the Achille's heel of fetoscopy. The aim of this study was to show in vivo feasibility of fetal membrane (FM) defect sealing by the application of tissue glues with umbrella-shaped receptors. METHODS: First, we adapted our previously described ex vivo strategy and evaluated the adhesion strength of different tissue glues, Histoacryl® and Glubran2®, by bonding polytetrafluoroethylene or silicone encapsulated nitinol glue receptor to human FM. Then, we exposed pregnant sheep uterus through a laparotomy and placed a 10-French trocar into the amniotic cavity through which the umbrella-shaped glue receptor (n = 9) was inserted and fixated onto the FM with the tissue glues (n = 8). The tightness of the sealed defects was assessed 4 h post-surgery. RESULTS: Both tissue glues tested resulted in adhesion of the glue receptors to the FM ex vivo. In vivo, all glue receptors opened in the amniotic cavity (n = 9) and all successfully placed glue receptors sealed the FM defect (n = 8). Four hours post-surgery, 2 treatment sites showed minimal leakage whereas the negative control without glue (n = 1) showed substantial leakage. DISCUSSION: This in vivo study confirms that fetoscopically induced FM defects can be sealed by the application of tissue adhesives.

Spontaneous septostomy in a monochorionic-diamniotic twin gestation.

Monochorionic twin gestations are associated with a greater incidence of neonatal morbidity and mortality when compared with their dichorionic counterparts. In turn, monochorionic-monoamniotic (MCMA) gestations carry greater risks compared with monochorionic-diamniotic (MCDA) gestations. While the true incidence of spontaneous septostomy of the dividing membranes (SSDM) in MCDA twins is unknown, SSDM has been demonstrated to be associated with increased morbidity and mortality, due to functional transition from a MCDA gestation to a MCMA gestation. We report a case of SSDM in a mid-trimester MCDA gestation, review the literature, and describe how to identify and manage this complication.

Ex-vivo mechanical sealing properties and toxicity of a bioadhesive patch as sealing system for fetal membrane iatrogenic defects.

Preterm prelabor rupture of membranes (PPROM) is the most frequent complication of fetal surgery. Strategies to seal the membrane defect created by fetoscopy aiming to reduce the occurrence of PPROM have been attempted with little success. The objective of this study was to evaluate the ex-vivo mechanical sealing properties and toxicity of four different bioadhesives integrated in semi-rigid patches for fetal membranes. We performed and ex-vivo study using term human fetal membranes to compare the four integrated patches composed of silicone or silicone-polyurethane combined with dopaminated-hyaluronic acid or hydroxypropyl methylcellulose (HPMC). For mechanical sealing properties, membranes were mounted in a multiaxial inflation device with saline, perforated and sealed with the 4 combinations. We measured bursting pressure and maximum pressure free of leakage (n = 8). For toxicity, an organ culture of membranes sealed with the patches was used to measure pyknotic index (PI) and lactate dehydrogenase (LDH) concentration (n = 5). All bioadhesives achieved appropriate bursting pressures, but only HPMC forms achieved high maximum pressures free of leakage. Concerning toxicity, bioadhesives showed low PI and LDH levels, suggesting no cell toxicity. We conclude that a semi-rigid patch coated with HPMC achieved ex-vivo sealing of iatrogenic defects in fetal membranes with no signs of cell toxicity. These results warrant further research addressing long-term adhesiveness and feasibility as a sealing system for fetoscopy.

Inter-foetus Membrane Segmentation for TTTS Using Adversarial Networks.

Twin-to-Twin Transfusion Syndrome is commonly treated with minimally invasive laser surgery in fetoscopy. The inter-foetal membrane is used as a reference to find abnormal anastomoses. Membrane identification is a challenging task due to small field of view of the camera, presence of amniotic liquid, foetus movement, illumination changes and noise. This paper aims at providing automatic and fast membrane segmentation in fetoscopic images. We implemented an adversarial network consisting of two Fully-Convolutional Neural Networks. The former (the segmentor) is a segmentation network inspired by U-Net and integrated with residual blocks, whereas the latter acts as critic and is made only of the encoding path of the segmentor. A dataset of 900 images acquired in 6 surgical cases was collected and labelled to validate the proposed approach. The adversarial networks achieved a median Dice similarity coefficient of 91.91% with Inter-Quartile Range (IQR) of 4.63%, overcoming approaches based on U-Net (82.98%-IQR: 14.41%) and U-Net with residual blocks (86.13%-IQR: 13.63%). Results proved that the proposed architecture could be a valuable and robust solution to assist surgeons in providing membrane identification while performing fetoscopic surgery.

Minimally Invasive Surgical Device for Precise Application of Bioadhesives to Prevent iPPROM.

INTRODUCTION: The benefits of endoscopic fetal surgery are deteriorated by the high risk of iatrogenic preterm prelabor rupture of fetal membranes (iPPROM). While previous studies have reported good sealing candidates to prevent membrane rupture, the delivery of these materials to the location of membrane puncture remains unsolved. MATERIALS AND METHODS: We describe an approach to apply sealing materials onto the amnion through the fetoscopy port. We developed a device composed of an umbrella-shaped polyester coated nitinol mesh and an applicator. The spontaneously unfolding umbrella is pushed through the port, pulled against the amnion, and glued onto the amnion defect site. We tested the adhesion strength of multiple glues and tested the feasibility and reproducibility of this fetal membrane sealing approach in an ex vivo model. RESULTS: The umbrella unfolded and was well positioned in all tests (n = 18). When applied via the fetoscopy port, umbrellas were successfully glued onto the fetal membrane, and all of them completely covered the defect (n = 5). The mean time needed for the whole procedure was 3 min. DISCUSSION: This study is a proof of concept presenting a potential future solution for the precise local application of bioadhesives for the prevention of iPPROM.

Tissuepatch is biocompatible and seals iatrogenic membrane defects in a rabbit model.

OBJECTIVE: To evaluate novel sealing techniques for their biocompatibility and sealing capacity of iatrogenic fetal membrane defects in a pregnant rabbit model. METHOD: At day 23 of gestation (term = d31), a standardized fetoscopy was performed through a 14G cannula. The resulting fetal membrane defect was closed with condensed collagen, collagen with fibrinogen, Tissuepatch, Duraseal, or a conventional collagen plug (Lyostypt) as reference. At d30, the fetuses were harvested and full thickness fetal membrane samples were analyzed. The study consisted of 2 consecutive parts: (1) biocompatibility testing by fetal survival, apoptosis, and infiltration of polymorphonuclear cells in the membranes and (2) the efficacy to seal fetal membrane defects. RESULTS: Three sealants (collagen with fibrinogen, Duraseal, or Lyostypt) were associated with a higher fetal mortality compared to control unmanipulated littermates and hence were excluded from further analysis. Tissuepatch was biocompatible, and amniotic fluid levels were comparable to those of control untouched littermates. Compared to the condensed collagen, Tissuepatch was also easier in surgical handling and induced limited cell proliferation. CONCLUSION: Tissuepatch had the best biocompatibility and efficacy in sealing an iatrogenic fetal membrane defect in the pregnant rabbit compared to other readily available sealants.

Bridge Suture for Successful McDonald Emergency Cerclage.

OBJECTIVES: To create awareness about a surgical technique termed bridge suture, which is performed as a pretreatment before a McDonald cerclage is performed on an emergency to treat severe cervical insufficiency. METHODS: Procedures for bridge suture were reviewed in detail and outcomes of 16 patients treated with bridge suture followed by McDonald cerclage were evaluated retrospectively. RESULTS: Using the bridge suture, the edges of uterine cervix were temporarily sutured and the external uterine os was closed, while the hourglass-shaped fetal membranes were concomitantly confined within the cervix; subsequently, a McDonald cerclage was performed. Over a 22-year period, 16 patients with a dilated cervix and bulging fetal membranes were treated using the technique of bridge suture followed by an emergency cerclage. The mean gestational age at cerclage was 22.5 weeks; the mean gestational age at delivery was 30.7 weeks; and the mean interval between cerclage and delivery was 8.2 weeks. In 15 out of 16 cases, cerclage was performed without encountering any complications. No maternal complications, including cervical laceration, were observed. The mean body weight of 17 neonates, including that of a twin, was 1,516 g and of them, 15 neonates survived. CONCLUSION: The important outcome of bridge suture is the replacement of fetal membranes back into the uterine cavity before McDonald's cerclage is performed. Pretreatment with bridge suture may facilitate the performance of a successful emergency cerclage and contribute to good maternal and neonatal outcomes.

Late postpartum hemorrhage due to placental and fetal membrane residuals: experience of two cases.

PURPOSE: To investigate the cause and preventative measures of late postpartum hemorrhage resulted from placental and fetal membrane residuals. MATERIALS AND METHODS: Retrospective analysis on 161 cases of late postpartum hemorrhage resulting from residuals of placenta and fetal membrane from 2002 to 2012. RESULTS: Among the 161 cases, there were 148 cases of vaginal delivery and 13 cases of cesarean section delivery. One hundred twenty-one cases (4.77%) of placental and fetal membrane residuals were present in 2,535 cases of pregnant women with history of abortion; 40 cases (2.01%) of placental and fetal membrane residuals were found in 1,989 cases of pregnant women without history of abortion. CONCLUSION: Placental and fetal membrane residuals are the major cause of late postpartum hemorrhage. Repeated abortion will increase the incidence of late postpartum hemorrhage resulting from placental and fetal membrane residuals.

Mussel mimetic tissue adhesive for fetal membrane repair: initial in vivo investigation in rabbits.

OBJECTIVE: Iatrogenic preterm prelabour rupture of fetal membranes (iPPROM) remains the main complication after invasive interventions into the intrauterine cavity. The aim of this study was to evaluate the sealing capability and tissue interaction of mussel-mimetic tissue adhesive (mussel glue) in comparison to fibrin glue on punctured fetal membranes in vivo. STUDY DESIGN: A mid-gestational rabbit model was used for testing the materials. The fetal sacs of pregnant rabbits at day 23 were randomly assigned into experimental groups: unoperated (negative control), unclosed puncture (positive control), commercially available fibrin glue (FG) with decellularized amnion scaffold (DAM), mussel glue (MG) with DAM, or mussel glue alone. Evaluation was done at term (30 days' gestation) assessing fetal survival, fetal membrane integrity and histology of the membranes. RESULTS: Fetal survival was not significantly lower in any of the treatment groups compared to the negative control. All plugging materials could be found at the end of the pregnancy and no adverse effects on the fetus or the pregnant does could be observed. Sac integrity was higher in all treatment groups compared to the positive control group but significant only in the FG+DAM group. Cellular infiltration could be seen in fibrin glue and DAM in contrast to mussel glue which was only tightly adhering to the surrounding tissue. These cells were mostly of mesenchymal phenotype staining positive for vimentin. CD68 positive macrophages were found clustered around all the plugging materials, but their numbers were only significantly increased for the mussel glue alone group compared to negative controls. CONCLUSIONS: Mussel glues performance in sealing fetal membranes in the rabbit model was comparable to that of fibrin glue. Taking into account its other favorable properties, it is a noteworthy candidate for a clinically applicable fetal membrane sealant.

Completely infarcted smooth muscle tumor of the placental membrane.

Non-trophoblastic tumor of the placenta is rare, and so is placental smooth muscle tumor. We report leiomyoma of the placental membrane, which was discovered on cesarean section. Histologically, the tumor was a benign leiomyoma with complete necrosis, and this finding was confirmed immunohistochemically. Only six cases of smooth muscle tumors of the placenta have been reported to date. This is the third report of leiomyoma involving the placental membrane.

A technique to increase accessibility to late-stage chick embryos for in ovo manipulations.

BACKGROUND: During early development, avian embryos are easily accessible in ovo for transplantations and experimental perturbations. However, these qualities of the avian embryonic model rapidly wane shortly after embryonic day (E)4 when the embryo is obscured by extraembryonic membranes, making it difficult to study developmental events that occur at later stages in vivo. RESULTS: In this study, we describe a multistep method that involves initially windowing eggs at E3, followed by dissecting away extraembryonic membranes at E5 to facilitate embryo accessibility in ovo until later stages of development. The majority of the embryos subjected to this technique remain exposed between E5 and E8, then become gradually displaced by the growing allantois from posterior to anterior regions. CONCLUSIONS: Exposed embryos are viable and compatible with embryological and modern developmental biology techniques including tissue grafting and ablation, gene manipulation by electroporation, and protein expression. This technique opens up new avenues for studying complex cellular interactions during organogenesis and can be further extrapolated to regeneration and stem cell studies.

Amniopatch for iatrogenic rupture of the fetal membranes.

With the increased use of invasive fetal procedures, the number of women facing post-procedure membrane rupture is increasing. Here we review the use of platelets and fresh frozen plasma for sealing iatrogenic fetal membrane defects by describing the mechanisms of action of the amniopatch procedure as well as published experience. In cases of iatrogenic preterm pre-labour rupture of the membranes, amniopatch effectively seals the fetal membranes in over two-thirds of cases. There is a risk of 16% of in utero fetal death, which may occur at varying intervals from the procedure and often for unknown reasons. Amniopatch has also been used as a treatment of chorionic membrane separation. In summary, current experience suggests that in cases of early onset but persistent amniotic fluid leakage following an invasive fetal procedure, amniopatch is an option.

Amniotic fluid volume and composition after fetal membrane resection in late-gestation sheep.

The chronically catheterized fetal sheep is a widely used model for fetal physiologic and pathophysiologic investigations. Catheterization involves opening the amniochorion to gain access to the fetus. In the current study, we explored the role of the amnion and amniochorion in maintaining normal amniotic fluid volume (AFV) and composition and fetal blood-gas status after surgery. Fetal sheep were catheterized at 119.6 ± 0.3 (mean ± SE, n = 25) d gestation (term, approximately 147 d). An opening equal to approximately 5% of total membrane surface area was created by resecting a portion of the amnion or amniochorion during surgery. The uterine wall was closed in all animals. Compared with control sheep (AFV = 992 ± 153 mL, n = 11), resection of the amnion had no significant effect on AFV (745 ± 156 mL, n = 7) measured 5 d after surgery, whereas resection of the amniochorion resulted in extensive loss of amniotic fluid (AFV = 131 ± 38 mL, n = 7). This loss resulted from extensive entry of amniotic fluid into the space between the chorion and uterine wall. Amniotic fluid, fetal plasma, and urinary solute concentrations; arterial pH; oxygen tension; and carbon dioxide tension were unchanged. A small opening in the amnion has minimal effects on ovine AFV, whereas a small opening in the amniochorion results in oligohydramnios. In addition, the amnion appears to be the primary site that limits the rate of amniotic fluid absorption by the chorionic vasculature.

A new technique using a rubber balloon in emergency second trimester cerclage for fetal membrane prolapse.

AIM: Prolongation of pregnancy in cases of fetal membrane prolapse into the vagina during the second trimester is difficult using conservative therapy. After pushing the membranes back into the cervix, emergency cervical cerclage may be advantageous in improving the neonatal outcome. We have been managing membrane repositioning and emergency cervical cerclage with a technique using a rubber balloon device (known as a 'mini metreu' in Japan), and we examined the efficacy of this technique in five cases. METHODS: Our management was as follows: initially, the full bladder technique was attempted under general anesthesia. If this was not effective, amnioreduction was performed by transabdominal amniocentesis. After the membrane repositioning using a mini metreu, double suture cervical cerclage (McDonald method + Shirodkar method) was performed. RESULTS: The diameter of the bulging prolapsed membranes ranged from 30-84 mm, with a mean of 52 mm. Cerclage was successfully performed in all of the five cases. Prolongation of the pregnancy period was from 22-107 days (average; 77.6 +/- 28.9 days). In cases 1-4, healthy newborns were delivered, but in case 5 sudden intrauterine fetal death due to umbilical cord complications occurred at 24 weeks of gestation. CONCLUSION: It appears that long-term prolongation of pregnancy is possible, when performing membrane repositioning using the mini metreu and emergency cervical cerclage for fetal membrane prolapse into the vagina.

Laparoscopic surgery of ectopic gestational sac implanted in the cesarean section scar.

AIM: The feasibility and outcome of laparoscopic surgery for patients with ectopic pregnancy in the cesarean section scar was studied. METHODS: From January 2003 to June 2007, 7 of 9 patients diagnosed with ectopic pregnancy in a previous cesarean section scar underwent laparoscopic removal of the gestational sac at our department. A retrospective review of medical records of these patients was performed. RESULTS: In all of them, the ectopic gestational sac was successfully removed by laparoscopy without converting to laparotomy and the scar defect was repaired by intracorporeal sutures. The mean operation time was 98 minutes (range: 30 to 210 min) and mean hemoglobin drop after operation was 2.3 g/dL (range: 1.2 to 3.4 g/dL). The mean postoperative hospital stay was 4.3 days (range: 3 to 7 d). None of the patients required additional methotrexate administration postoperatively. CONCLUSIONS: Laparoscopic removal of ectopic gestational sac within a cesarean scar seems to be a feasible and safe procedure that might be considered as a treatment option.

A randomized trial of amnioreduction versus septostomy in the treatment of twin-twin transfusion syndrome.

OBJECTIVE: Left untreated, severe twin-to-twin transfusion syndrome (TTTS) presenting in the early second trimester of pregnancy is often associated with significant maternal morbidity and almost universal perinatal loss. Removal of excessive amounts of amniotic fluid through serial amniocenteses (amnioreduction) has been the mainstay of therapy. We sought to compare amnioreduction to intentional perforation of the intervening twin membrane (septostomy). STUDY DESIGN: Pregnant women with TTTS before 24 weeks' gestation were randomly assigned to serial amnioreduction or septostomy. A single puncture technique under ultrasound guidance was used for the septostomy. The primary outcome measure was survival to neonatal discharge, and was assessed based on the number of pregnancies or the number of fetuses as appropriate. RESULTS: The study was terminated at the planned interim analysis stage after 73 women were enrolled. This was because the rate of survival of at least 1 infant was similar in the amnioreduction group compared to the septostomy group (78% vs 80% of pregnancies, respectively; RR=0.94, 95%CI 0.55-1.61; P=.82). Patient undergoing septostomy were more likely to require a single procedure for treatment (64% vs 46%; P=.04). CONCLUSION: Although overall perinatal survival is not enhanced, septostomy offers the advantage of often requiring a single procedure compared to serial amnioreduction in the treatment of severe twin-to-twin transfusion syndrome.

The closure of iatrogenic membrane defects after amniocentesis and endoscopic intrauterine procedures.

OBJECTIVE: To describe a new technique for wound closure after endoscopic intrauterine procedures which prevents amniotic fluid leakage after the procedure. STUDY DESIGN: This is an observational study which reviews a new technique under an IRB-approved protocol. The rationale for this study was the increasing frequency of intrauterine endoscopic procedures. The most common complication of these procedures is persistent leakage of amniotic fluid from puncture sites, which can result in preterm labor and preterm delivery. Thus, these procedures carry a high morbidity rate that may overcome the benefit of the intervention. We have employed a new technique, which has successfully prevented amniotic fluid leakage following the procedure. The instruments used for the endoscopic procedures were no larger than 3.5 mm for all cases. A sealant of platelets was rapidly injected followed by injection of fibrin glue and powdered collagen slurry at each puncture site. Sonography for modified AFI, clinical examination for nitrazine and ferning, and pad count were performed after each procedure at three intervals: immediately after the procedure, 24 h and 48 h. RESULTS: Eight patients undergoing an endoscopic intrauterine procedure (either cord ligation for twin-twin transfusion syndrome or sealing of ruptured membranes after amniocentesis) were included. All patients were treated between 18 and 24 weeks of gestation. Sonography, clinical examination and pad count revealed no evidence of amniotic fluid leakage either intra-abdominally or vaginally in any of the patients. There was 1 patient who ruptured membranes 12 h after the procedure due to severe vomiting. Another patient elected to terminate the pregnancy 48 h after the procedure without evidence of leakage. The remaining patients continued for 8 weeks or more without fluid leakage. CONCLUSION: The technique described, immediate sealing of puncture wounds following endoscopic intrauterine procedures, is effective in preventing amniotic fluid loss after the procedure.