Percutaneous fetoscopic closure of large open spina bifida using a bilaminar skin substitute.

OBJECTIVE: We have described previously our percutaneous fetoscopic technique for the treatment of open spina bifida (OSB). However, approximately 20-30% of OSB defects are too large to allow primary skin closure. Here we describe a modification of our standard technique using a bilaminar skin substitute to allow closure of large spinal defects. The aim of this study was to report our clinical experience with the use of a bilaminar skin substitute and a percutaneous fetoscopic technique for the prenatal closure of large OSB defects. METHODS: Surgery was performed between 24.0 and 28.9 gestational weeks with the woman under general anesthesia, using an entirely percutaneous fetoscopic approach with partial carbon dioxide insufflation of the uterine cavity, as described previously. If there was enough skin to be sutured in the midline, only a biocellulose patch was placed over the placode (single-patch group). In cases in which skin approximation was not possible, a bilaminar skin substitute (two layers: one silicone and one dermal matrix) was placed over the biocellulose patch and sutured to the skin edges (two-patch group). The surgical site was assessed at birth, and long-term follow-up was carried out. RESULTS: Percutaneous fetoscopic OSB repair was attempted in 47 consecutive fetuses, but surgery could not be completed in two. Preterm prelabor rupture of membranes (PPROM) occurred in 36 of the 45 (80%) cases which formed the study group, and the mean gestational age at delivery was 32.8 ± 2.5 weeks. A bilaminar skin substitute was required in 13/45 (29%) cases; in the remaining 32 cases, direct skin-to-skin suture was feasible. There were 12 cases of myeloschisis, of which 10 were in the two-patch group. In all cases, the skin substitute was located at the surgical site at birth. In five of the 13 (38.5%) cases in the two-patch group, additional postnatal repair was needed. In the remaining cases, the silicone layer detached spontaneously from the dermal matrix (on average, 25 days after birth), and the lesion healed by secondary intention. The mean operating time was 193 (range, 83-450) min; it was significantly longer in cases requiring the bilaminar skin substitute (additional 42 min on average), although the two-patch group had similar PPROM rate and gestational age at delivery compared with the single-patch group. Complete reversal of hindbrain herniation occurred in 68% of the 28 single-patch cases and 33% of the 12 two-patch cases with this information available (P < 0.05). In four cases there was no reversal; half of these occurred in myeloschisis cases. CONCLUSIONS: Large OSB defects may be treated successfully in utero using a bilaminar skin substitute over a biocellulose patch through an entirely percutaneous approach. Although the operating time is longer, surgical outcome is similar to that in cases closed primarily. Cases with myeloschisis seem to have a worse prognosis than do those with myelomeningocele. PPROM and preterm birth continue to be a challenge. Further experience is needed to assess the risks and benefits of this technique for the management of large OSB defects. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Identification of essential steps in laser procedure for twin-twin transfusion syndrome using the Delphi methodology: SILICONE study.

OBJECTIVE: To determine, by expert consensus, the essential substeps of fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) that could be used to create an authority-based curriculum for training in this procedure among fetal medicine specialists. METHODS: A Delphi survey was conducted among an international panel of experts (n = 98) in FLS. Experts rated the substeps of FLS on a five-point Likert-type scale to indicate whether they considered them to be essential, and were able to comment on each substep, using a dedicated online platform accessed by the invited tertiary care facilities that specialize in fetal therapy. Responses were returned to the panel until consensus was reached (Cronbach's α ≥ 0.80). All substeps that were rated ≥ 4 by 80% of the experts were included in the evaluation instrument. RESULTS: After the first iteration of the Delphi procedure, a response rate of 74% (73/98) was reached, and in the second and third iterations response rates of 90% (66/73) and 81% (59/73) were reached, respectively. Among a total of 81 substeps rated in the first round, 21 substeps had to be re-rated in the second round. Finally, from the initial list of substeps, 55 were agreed by experts to be essential. In the third round, the 18 categorized substeps were ranked in order of importance, with 'coagulation of all anastomoses that cross the equator' and 'determination of fetoscope insertion site' as the most important. CONCLUSIONS: A total of 55 substeps of FLS for TTTS were defined by a panel of experts to be essential in the procedure. This list is the first authority-based evidence to be used in the development of a final training model for future fetal surgeons.

Management of twin-twin transfusion syndrome in pregnancies with iatrogenic detachment of membranes following therapeutic amniocentesis and the role of interim amniopatch.

OBJECTIVE: Detachment of membranes may occur after therapeutic amniocentesis for twin-twin transfusion syndrome (TTTS). Subsequent amniocenteses or endoscopic fetal therapy may be hindered or made altogether impossible by this complication. The purpose of this study was to describe our experience in the assessment and management of TTTS patients with iatrogenic detached membranes (IDM). METHODS: Patients with IDM referred for fetal surgery for TTTS were considered ineligible for standard surgery and were offered different alternatives, including expectant management, serial amniocentesis, or an attempt at surgery with or without prior amniopatch. Pregnancy outcomes were compared between surgical and non-surgical patients. RESULTS: Nine hundred and forty-four patients with a diagnosis of TTTS were referred between July 1997 and December 2004, of whom 322 (34.1%) had a prior therapeutic amniocentesis. Twenty-six of the 322 patients (8%) had IDM. Ten patients opted to be managed with subsequent amniocenteses, two of which had an amniopatch. One patient had voluntary interruption of pregnancy. Fifteen patients underwent surgery, 10 of whom underwent an amniopatch. Overall, resealing of membranes occurred in 8/12 (66%) patients treated with an amniopatch. Survival of at least one fetus was greater in patients treated surgically with or without an amniopatch (12/15, 80% vs. 4/11, 36%, P = 0.04). CONCLUSION: Membrane detachment is an important complication of therapeutic amniocentesis in the treatment of TTTS. Although successful treatment of IDM can be achieved with an interim amniopatch, this alternative is not without risks. Therapeutic amniocenteses should be discouraged in patients considering endoscopic fetal surgery for TTTS.

The impact of route of delivery and presentation on twin neonatal and infant mortality: a population-based study in the USA, 1995-97.

OBJECTIVE: We examined whether the route of delivery for near-term (> or = 34 weeks' gestation) twins, as candidates for vaginal delivery, affected neonatal and infant mortality rates. We further evaluated whether these mortality rates were modified by fetal presentation. METHODS: A population-based retrospective cohort study based on the matched multiple births data in the USA (1995-97) was performed. Analyses were restricted to non-malformed liveborn twins delivered at (> or = 34 weeks' gestation. Twins with breech-breech and breech-vertex presentations were excluded, since they are not candidates for vaginal delivery. Neonatal mortality rates (death within the first 27 days) and post-neonatal mortality rates (death between 28 and 365 days) per 1000 twin live births, by route of delivery and fetal presentation, were derived. The associations between neonatal mortality, post-neonatal mortality and the route of delivery for vertex-breech versus vertex-vertex presentations were expressed based on relative risks (RR) and 95% confidence intervals (CI) derived from logistic regression models based on the method of generalized estimating equations. RESULTS: Of the 177,622 twins analyzed, 87% (n = 154,531) presented as vertex-vertex. Fifty-five per cent (n = 97,692) of twins were both delivered vaginally, 41% (n = 72,825) were both delivered by Cesarean section and, of the remaining 4% (n = 7,105), the first twin was delivered vaginally and the second by Cesarean section. Twins with vertex-breech presentations delivered by Cesarean-cesarean sections, as well as those with vertex-vertex presentations delivered vaginally, had the lowest neonatal mortality rate (1.6 per 1000 live births). The highest neonatal mortality rate in the vertex-breech pairs occurred with vaginal-Cesarean deliveries (2.7 per 1000 live births). Among twins with vertex-vertex presentations, twins delivered via the vaginal-Cesarean route experienced the highest neonatal mortality (3.8 per 1000 live births). The RR for neonatal mortality in this group was 2.24 (95% CI 1.35, 3.72) compared with twins both delivered vaginally. CONCLUSION: Route of delivery and fetal presentation both confer an impact on twin infant mortality rates. Strategies to reduce discordant routes in complicated vaginal deliveries may lead to improved neonatal survival.