Case of Prenatal Diagnosis of a Fetal Pulmonary Arteriovenous Malformation at Term.

In our case, the malformation was diagnosed prenatally at 40 weeks of gestation, and at the age of 14 days, the malformation was removed combined with a segmentectomy of the sixth segment of the left lung. Preoperative diagnostics focus on 3D-CT reconstruction and detailing of the anatomical variations of all arterial and venous vessels, as evident from our case. Treatment includes surgical removal or a minimally invasive interventional approach through the embolization of the vessel afferent to the malformation. After the operation, the child was discharged on the 30th day after birth in good condition and is developing normally. Early operative intervention is of great importance for the favorable outcome of the condition. In our case, this was hypoxemia with a saturation of 70-75%. The rare and often missed prenatal diagnosis of fetal AV malformation is significant for the adequate postnatal treatment and development of affected children.

Macroscopic and histopathologic findings in a laparoschisis model in fetal sheep: comparisons with gastroschisis in human fetuses and implications for prenatal interventions.

PURPOSE: In order to further define the challenges, minimally invasive fetal surgery will have to overcome human fetuses with gastroschisis. The purpose of this study was to compare macroscopic and histopathologic characteristics of experimental laparoschisis in sheep fetuses with actual cases of gastroschisis from a postmortem series of human fetuses. METHODS: Employing fetoscopy, we created a laparoschisis model in eight fetal sheep between 74 and 92 days of gestation (median 86.5 days). Twenty to 31 days after fetoscopic creation of fetal laparoschisis, six surviving fetuses were harvested for macroscopic and histopathologic assessments of the experimental lesion. These findings were compared to those of ten human fetuses with gastroschisis after termination of pregnancy. RESULTS: In the six sheep fetuses, both macroscopic and histopathologic intestinal changes achieved by this animal model resembled those of the human fetuses with gastroschisis. The surface of the intestine, liver and stomach exposed to the amniotic fluid was covered by a thick pseudocapsule made up of reactive fibroblasts and a dense capillary network. Parts of the capsule showed a foreign body-type reaction. CONCLUSIONS: Macroscopic and histopathological findings in a new minimally invasive laparoschisis model in sheep resemble those found in human fetuses with gastroschisis. The new model seems therefore suitable for assessing the potential of prenatal minimally invasive fetoscopic interventions in this condition.

Partial amniotic carbon dioxide insufflation during minimally invasive fetoscopic interventions seems safe for the fetal brain in sheep.

BACKGROUND: Partial amniotic carbon dioxide insufflation (PACI) during fetoscopic interventions greatly improves visualization of intraamniotic contents. The purpose of this study was to assess any histologically discernable effects from this approach on the fetal brain after long-term survival in sheep. METHODS: Six pregnant ewes between 63 and 92 days of gestation underwent PACI after fetoscopic intraamniotic access. Insufflation pressures ranged between 7 and 15 mm Hg (mean 11.7; median 12.5). Insufflation times ranged between 45 and 80 minutes (mean 55.8 minutes; median 52.5) and depended on the duration of various percutaneous fetoscopic maneuvers (e.g., posturing, fetal transesophageal electrocardiography, and chronic fetal vascular access) that were tested during these studies. After fetal spontaneous delivery between 147 and 150 days of gestation, 5 of the lambs were observed for abnormal neurological symptoms. The last ewe and her sheep were terminated at 133 days of gestation for humane reasons. All six brains were examined for hemorrhage, embolism, infarctions, inflammatory changes, and abnormal cortical maturation. An unoperated sibling was available as a control. RESULTS: The 5 sheep that were spontaneously delivered exhibited no abnormal neurological findings. In all 6 sheep, PACI did not result in any histologically discernable damage to their brain in these long-term studies. Maternal and fetal complications were not observed during or after the approach. CONCLUSION: The application of PACI during minimally invasive fetoscopic interventions seems safe for the fetal brain. Due to the still limited clinical experience with PACI, continued assessment of its maternal and fetal risks as well as management are required.

Maternal complications of fetoscopic laser photocoagulation (FLP) for treatment of twin-twin transfusion syndrome (TTTS).

AIMS: Fetoscopic laser photocoagulation (FLP) has become standard therapy for severe twin-twin transfusion syndrome. Data on adverse maternal events are rare. We performed a literature review to obtain data on maternal complications of FLP. METHODS: Extensive literature review, searching MEDLINE and other databases from 1990 to 2009, using MESH-terms and further keywords. Data extraction was performed using the following criteria: (i) maternal complications reported as primary or secondary outcome parameters; (ii) any comment on adverse maternal events. RESULTS: Of 321 publications found 40 were included, comprising 1785 patients. The overall rate of adverse maternal events was 5.4%. In studies with systematic assessment (n=3, 379 patients) the complication rate was significantly higher (17.4% vs. 2.2%, P<0.0001). Adverse events were classified and the rate was 1.0% (1.8% vs. 0.8%, P=0.12) for severe complications; 2.9% (11.9% vs. 0.5%, P<0.0001) for intermediate/minor adverse events; and 1.5% (3.7% vs. 0.9%, P<0.0001) for complications with undetermined relevance. CONCLUSIONS: High-quality data on maternal complications of FLP are rare. With systematic assessment, the rate of adverse events is significantly higher. Underreporting has to be assumed. Further studies are required to confirm these data.

Partial amniotic carbon dioxide insufflation (PACI) during minimally invasive fetoscopic surgery: early clinical experience in humans.

BACKGROUND: The technical performance of minimally invasive fetoscopic surgery may be severely hindered by poor visualization of intra-amniotic contents. Partial amniotic carbon dioxide insufflation (PACI) allows the visual limitations of operating within the fluid environment to be overcome. PATIENTS AND METHODS: When amniotic fluid exchange failed to improve fetoscopic visualization, PACI was attempted during 37 fetoscopic procedures between 17 + 5 and 33 + 2 weeks of gestation. PACI was attempted with filtered carbon dioxide using a commercially available insufflator via one to three trocars that were percutaneously introduced into the amniotic cavity. The maximum pressure during PACI was limited by the maximum insufflation pressure (30 mmHg) generated by the insufflator. Improvement of fetoscopic visualization as well as technical, maternal, and fetal safety aspects surrounding PACI were analyzed. RESULTS: PACI could successfully be instituted in 36 of the 37 procedures. In one case, when in the presence of increased uterine tone the opening pressure exceeded the maximum insufflation pressure of the insufflator, the strategy was abandoned. In all cases where PACI could be instituted successfully, the approach offered far superior visualization of the fetoscopic procedure than would have been possible within amniotic fluid. Acute or chronic maternal or fetal complications were observed in only one case (intraoperative membrane rupture). CONCLUSION: PACI greatly improves fetal visualization during fetoscopic interventions when fetoscopy within fluid meets with difficulties. Continued assessment of its benefits, risks, and safety margins at specialist centers is required.

Is there a therapeutic role for fetoscopic surgery in the prenatal treatment of gastroschisis? A feasibility study in sheep.

BACKGROUND/PURPOSE: Gastroschisis is a malformation of the anterior abdominal wall that consists of a right paraumbilical defect with bowel loops bathed in the amniotic fluid. The prognosis relies mainly on morbidity attributable to intrauterine bowel loss or postpartum bowel dysfunction. The purpose of this study was to evaluate a potential role for fetoscopic surgery in severely affected fetuses with this condition. METHODS: Employing fetoscopy, we created a laparoschisis model in eight fetal sheep between 74-92 days of gestation; median 86.5 days). Twenty to 31 days after fetoscopic creation of fetal laparoschisis, a second procedure was scheduled in six survivors of the first surgery with the goal of assessing the potential for fetoscopic intervention in this condition. RESULTS: In the six survivors, macroscopic intestinal changes achieved by this animal model resembled those of human fetuses with gastroschisis. Whereas fetoscopic enlargement of the defect within the abdominal wall was feasible, in none of the fetuses was return of herniated abdominal viscera followed by abdominal closure possible using fetoscopic instrumentation. Furthermore, any attempt to return the herniated viscera into the fetal abdomen resulted in immediate and severe hemodynamic compromise of the fetoplacental circulation by stretching of the intra-abdominal umbilical arteries and vein. CONCLUSION: Minimally invasive fetoscopic enlargement of the defect within the abdominal wall is feasible in sheep fetuses with iatrogenic laparoschisis. This approach might benefit human fetuses with gastroschisis considered at high risk for bowel loss by constriction at the defect site. In contrast, return of herniated abdominal viscera followed by abdominal closure is limited by physiological constraints and seems currently not feasible with current fetoscopic instrumentation.

Life-saving effects of fetal tracheal occlusion on pulmonary hypoplasia from preterm premature rupture of membranes.

BACKGROUND: Preterm premature rupture of membranes before 22 weeks of gestation may result in severe fetal pulmonary hypoplasia. Fetoscopic tracheal balloon occlusion might result in catch-up pulmonary growth. CASE: After preterm premature rupture of membranes at 16 weeks of gestation, magnetic resonance imaging at 26 0/7 weeks showed a fetal lung volume of 13 mL and pulmonary blood flow hardly could be detected. Fetoscopic tracheal balloon occlusion was performed at 27 6/7 weeks; within 6 days, fetal lung volume increased to 70 mL and lung blood flow normalized. The fetus was delivered electively at 28 6/7 weeks. Six hours after delivery, the neonate required only 21% oxygen and was extubated after 55 hours. CONCLUSION: Short-term fetoscopic tracheal balloon occlusion may result in rapid normalization of fetal lung volume and blood flow in fetuses with life-threatening pulmonary hypoplasia from preterm premature rupture of membranes before 22 weeks of gestation.

Percutaneous fetoscopic patch closure of human spina bifida aperta: advances in fetal surgical techniques may obviate the need for early postnatal neurosurgical intervention.

BACKGROUND: A percutaneous minimally invasive fetoscopic approach was attempted for closure of a spina bifida aperta in two fetuses with L5 lesions. The goal was to obviate the need for postnatal neurosurgery to manage this condition. METHODS AND RESULTS: The percutaneous fetoscopic procedures were performed by a two-layer approach at respectively 22+/-2 and 22+/-4 weeks of gestation. The fetuses were delivered respectively at 32+/-6 and 32+3 weeks of gestation. Their neural cords were completely covered although in small areas skin closure was incomplete. Postnatally, complete skin closure occurred beneath an occlusive draping within 2 to 3 weeks such that neurosurgical intervention was not required. Both neonates showed reversal of hindbrain herniation, near-normal leg function, and satisfactory bladder and bowel function. For one of the two fetuses, ventriculoperitoneal shunt insertion was not required. CONCLUSIONS: Percutaneous minimally invasive fetoscopic patch closure of spina bifida aperta offers a substantially less maternal trauma than open fetal surgical repair and currently may even obviate the need for postnatal neurosurgical repair. With a little further improvement in surgical techniques and a better understanding of incorporating surgical patches into the fetus, complete skin closure seems possible in the near future.

Encouraging early clinical experience with deliberately delayed temporary fetoscopic tracheal occlusion for the prenatal treatment of life-threatening right and left congenital diaphragmatic hernias.

OBJECTIVE: In order to assess the effect of deliberately delayed percutaneous fetoscopic tracheal occlusion on survival of fetuses with life-threatening congenital diaphragmatic hernia. METHODS: Eight fetuses with life-threatening congenital diaphragmatic hernia underwent fetoscopic tracheal balloon occlusion between 29 + 0 and 32 + 4 weeks of gestation. Delayed occlusion was chosen in order to minimize potentially negative pulmonary effects from premature delivery as a result of fetal surgery. In addition, we wanted to become able to provide all available postnatal intensive care treatment means in these patients. RESULTS: Six of the 8 fetuses survived to discharge from hospital. CONCLUSION: Delayed fetoscopic tracheal balloon occlusion may be rewarded with lung growth sufficient to allow survival of fetuses with life-threatening congenital diaphragmatic hernia.