Prenatal Risk Factors and Outcomes of Pseudoamniotic Band Sequence following Fetoscopic Laser Surgery: Systematic Review, and Meta-Analysis

BACKGROUND

Pseudoamniotic band sequence (PABS) is a rare iatrogenic consequence of invasive fetal interventions, most commonly fetoscopic laser surgery (FLS) in monochorionic multiple pregnancies complicated by twin-to-twin transfusion syndrome (TTTS).

OBJECTIVES

The aim of this study was to investigate prenatal risk factors and perinatal outcomes for pregnancies involving PABS after FLS for TTTS and compare outcomes between those undergoing fetoscopic band release versus not.

METHOD

We conducted a systematic search of PubMed, Scopus, and Web of Science on studies reporting PABS following FLS for TTTS. A meta-analysis of pooled proportions was conducted.

RESULTS

There were 16 studies covering 47 pregnancies complicated by PABS following FLS, mostly case series and case reports. The incidence of PABS was 2%, with the recipient twin affected in 94% of the cases. Pregnancies complicated by PABS were associated with inter-twin septostomy in 32% and chorioamniotic separation (CAS) in 90%. The mean gestational age (GA) at FLS and delivery were 17.7 and 30.9 weeks, respectively. Preterm premature rupture of membranes (PPROM) happened in 62% of pregnancies. The risk of preterm birth (PTB) <34 weeks, <32 weeks, and <28 weeks were 94%, 67%, and 31%, respectively. There were 41% fetal demises and 64% live births among the affected fetuses. Results of fetoscopic band release versus not were comparable, including GA at delivery, PPROM, and PTB at 32 weeks. It was noted that the likelihood of PTB by 28 weeks (67% vs. 23%) and fetal death (50% vs. 39%) were higher in the band release group. It was similar between groups in terms of postnatal amputation.

CONCLUSIONS

PABS causes amputations or fetal death in more than one-third of cases. Pregnancies with an inter-twin septostomy, CAS, advanced TTTS staging, and early GA are more likely to experience PABS. In addition, more than a third of FLS-treated TTTS resulted in PTB and PPROM. PABS cases with prenatal band release showed higher rates of PTB and fetal death, but the data were from small, heterogeneous studies.

Ultrasound findings in Pseudoamniotic band syndrome after fetoscopic surgery: Antenatal description of three cases and review of literature

INTRODUCTION

Pseudoamniotic Bands Syndrome (PABS) was described as iatrogenic complication from in utero procedure as fetoscopy.

OBJECTIVE

The aim of our study was to identify the ultrasound findings in PABS diagnosed prenatally METHODS: First, we reported cases of PABS following fetoscopic surgery that were diagnosed prenatally in our institution. We collected all ultrasound data with fetal and neonatal issues. Then, a literature review was conducted by searching the Medline and Cochrane Library computer databases until 2020 to find publications that involve PABS diagnosed prenatally or postnatally. The following keywords were selected and combined: "pseudoamniotic bands syndrome", "fetoscopy", "fetal surgery".

RESULTS

We collected three cases of PABS diagnosed prenatally in our center following fetoscopic procedures for complicated monochorionic pregnancies. Among these cases, we reported the following ultrasound findings: floating membrane, amniotic bands, striction of limbs, perilesional edema, reduced member size and anomalies of Doppler flow. Including our cases, we reported 23 published PABS of which eight (35%) were prenatally diagnosed. When it was diagnosed, mean GA at PABS diagnosis was 23 weeks (mean interval from fetoscopic to diagnosis was 4 weeks). Three fetoscopic release of amniotic bands were described. The principal parts affected were the limbs, more particularly the extremities.

CONCLUSION

PABS was accessible to an antenatal diagnosis, as well as ABS. Although it is a rare complication of fetoscopic surgery, ultrasound examinations after procedure should focus on PABS signs to improve prognosis of the neonates.

Effects and outcomes of septostomy in twin-to-twin transfusion syndrome after fetoscopic laser therapy

Background

To evaluate the incidence and outcomes of septostomy in twin-to-twin transfusion syndrome (TTTS) after fetoscopic laser therapy.

Methods

A retrospective analysis of TTTS postlaser septostomy between 2005 and 2018 was performed. Postlaser septostomy was diagnosed using both (1) a free-floating intertwin membrane flap visible on ultrasound examination and (2) the rapid equalization of amniotic fluid maximum vertical pocket in the donor and recipient amniotic sacs observed after laser therapy. Perinatal survival, neonatal brain image anomaly, gestational age at operation and birth, incidence of premature rupture of membranes (PROM) within 3 weeks after operation, pseudoamniotic band syndrome, and cord entanglement were evaluated.

Results

In the 159 TTTS cases included, 12 had postlaser septostomy. Relative to the group without septostomy, the septostomy group had a lower total fetal survival rate (54.2% vs 73.6%, p = 0.041), an earlier mean gestational age at delivery (27.8 vs 34.4 weeks, p = 0.009), a higher risk of PROMs within 3 weeks after operation (33.3% vs 5.4%, p = 0.004), a higher cord entanglement rate (16.7% vs 0%, p = 0.005), and a higher brain image anomaly rate (23.0% [3/13] vs 5.0% [11/218], p = 0.035). After considering the severe Quintero stages (stage III and IV), postlaser septostomy was the only variable [p = 0.003, odds ratio = 5.1] to predict neonatal brain image anomaly. Postlaser septostomy combined with severe Quintero stages could predict PROMs within 3 weeks after laser therapy [p = 0.001, odds ratio = 14.1 and p = 0.03, odds ratio = 5.4, respectively] and delivery before the gestational age of 28 weeks [p = 0.017, odds ratio = 4.5 and p = 0.034, odds ratio = 2.3, respectively]. The risk of pseudoamniotic band syndrome was not increased by postlaser septostomy in this case series.

Conclusions

Postlaser septostomy in TTTS was associated with poorer fetal survival and more adverse perinatal outcomes even after considering severe Quintero stages before laser therapy. Efforts should be made to prevent septostomy during laser therapy, and septostomy as the primary method to treat TTTS is not advisable.