Prenatally Diagnosed Large Lung Lesions: Timing of Resection and Perinatal Outcomes

INTRODUCTION

Fetuses with large lung lesions including congenital cystic adenomatoid malformations (CCAMs) are at risk for cardiopulmonary compromise. Prenatal maternal betamethasone and cyst drainage for micro- and macrocystic lesions respectively have improved outcomes yet some lesions remain large and require resection before birth (open fetal surgery, OFS), at delivery via an Ex Utero Intrapartum Treatment (EXIT), or immediately post cesarean section (section-to-resection, STR). We sought to compare prenatal characteristics and outcomes in fetuses undergoing OFS, EXIT, or STR to inform decision-making and prenatal counseling.

METHODS

A single institution retrospective review was conducted evaluating patients undergoing OFS, EXIT, or STR for prenatally diagnosed lung lesions from 2000 to 2021. Specimens were reviewed by an anatomic pathologist. Lesions were divided into "CCAMs" (the largest pathology group) and "all lung lesions" since pathologic diagnosis is not possible during prenatal evaluation when care decisions are made. Prenatal variables included initial, greatest, and final CCAM volume-ratio (CVR), betamethasone use/frequency, cyst drainage, and the presence of hydrops. Outcomes included survival, ECMO utilization, NICU length of stay (LOS), postnatal nitric oxide use, and ventilator days.

RESULTS

Sixty-nine percent (59 of 85 patients) of lung lesions undergoing resection were CCAMs. Among patients with pathologic diagnosis of CCAM, the initial, largest, and final CVRs were greatest in OFS followed by EXIT and STR patients. Similarly, the incidence of hydrops was significantly greater and the rate of hydrops resolution was lower in the OFS group. Although the rate of cyst drainage did not differ between groups, maternal betamethasone use varied significantly (OFS 60.0%, EXIT 100.0%, STR 74.3%; p = 0.0378). Notably, all OFS took place prior to 2014. There was no difference in survival, ventilator days, nitric oxide, NICU LOS, or ECMO between groups. In multiple variable logistic modeling, determinants of survival to NICU discharge among patients undergoing resection with a pathologic diagnosis of CCAM included initial CVR <3.5 and need for <3 maternal betamethasone doses.

CONCLUSION

For CCAMs that remain large despite maternal betamethasone or cyst drainage, surgical resection via OFS, EXIT, or STR are viable options with favorable and comparable survival between groups. In the modern era there has been a shift from OFS and EXIT procedures to STR for fetuses with persistently large lung lesions. This shift has been fueled by the increased use of maternal betamethasone and introduction of a Special Delivery Unit during the study period and the appreciation of similar fetal and neonatal outcomes for STR vs. EXIT and OFS with reduced maternal morbidity associated with a STR. Accordingly, efforts to optimize multidisciplinary perinatal care for fetuses with large lung lesions are important to inform patient selection criteria and promote STR as the preferred surgical approach in the modern era.

LEVEL OF EVIDENCE

Level IV.

Error traps in fetal surgery

The growth of the field of fetal surgery over the last two decades driven by new indications and data from prospective randomized trials supporting prenatal intervention has resulted in techniques protocols and methodologies that have gained confidence by insuring good outcomes. Error traps are methods or techniques that usually work well in most of the cases, but which are apt to fail under certain specific circumstances. The very confidence the surgeon develops in these techniques or methodologies makes them a trap for the unwary surgeon. The purpose of this article is to discuss common error traps in fetal interventions, including ultrasound guided procedures, fetoscopic surgery, open fetal surgery and EXIT procedures. Awareness of these error traps and approaches to avoid them may enhance fetal surgical outcomes and reduce complications rates.

MOMS Plus: Single-Institution Review of Outcomes for Extended BMI Criteria for Open Fetal Repair of Myelomeningocele

BACKGROUND

In utero repair has become an accepted therapy to decrease the rate of ventriculoperitoneal shunting and improve neurologic function in select cases of myelomeningocele. The Management of Myelomeningocele Study (MOMS) trial excluded patients with a BMI >35 due to concerns for increased maternal complications and preterm delivery, limiting the population that may benefit from this intervention.

OBJECTIVES

The aim of this study was to evaluate outcomes associated with extending the maternal BMI criteria to 40 in open fetal repair of myelomeningocele.

METHOD

Retrospective review of fetal closure of myelomeningocele at a quaternary referral center between 2013 and 2016 with maternal BMI ranging from 35 to 40.

RESULTS

Eleven patients with a BMI >35 were identified. The average BMI was 37. The average maternal age at the time of evaluation was 27 years. The average gestational age at fetal surgery was 24 weeks. Gestational age at birth was an average of 32 weeks. There was one perinatal death immediately following the fetal intervention. The shunt rate at 1 year was 45% (5/11 patients).

CONCLUSIONS

In this single-institution review of expanded BMI criteria for fetal repair of myelomeningocele, we did not observe any adverse maternal outcomes associated with maternal obesity; however, the gestational age at delivery was 2 weeks earlier compared to the MOMS trial.

Fetal Myelomeningocele Repair through a Mini-Hysterotomy

OBJECTIVE

To present the feasibility of fetal myelomeningocele (MMC) repair through a mini-hysterotomy and to describe the perinatal results from our initial experience.

METHODS

A descriptive study of cases of fetal MMC correction via mini-hysterotomy performed between 2014 and 2016.

RESULTS

Forty-five women underwent fetal surgery and 87% (39/45) delivered. A complete multilayer correction of the MMC was possible in all cases. There were no maternal, fetal or neonatal deaths. No maternal or fetal complications occurred from fetal MMC correction until maternal hospital discharge. The average gestational age (GA) at surgery was 24.5 weeks (standard deviation, SD: 1.7; range: 20.7-26.9). The median hysterotomy length was 3.05 cm (SD: 0.39; range: 2.50-3.50). One patient (1/39; 2.6%) experienced chorioamniotic separation. Nine patients (9/39; 23.1%) had premature preterm rupture of membranes at a median GA of 34.1 weeks (range: 31.1-36.0). The average GA at delivery was 35.3 weeks (SD: 2.2; range: 27.9-39.1). Ninety-five percent (37/39) of our patients had an intact hysterotomy site at delivery. Ventriculoperitoneal shunt placement was necessary for 7.7% (3/39) of the neonates.

CONCLUSION

Fetal MMC repair is feasible through a mini-hysterotomy. This approach appears to be associated with reduced risks of very preterm delivery and maternal, fetal and neonatal complications.