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Key Points
The range of interventional procedures continues to grow with refinements in criteria for treatment, technique, and instrumentation.
Shunts work well to decompress thoracic fluid collections such as pleural effusions and cysts in congenital pulmonary airway malformation (CPAM; formerly known as congenital cystic adenomatoid malformation [CCAM]).
Shunts work less well for treating bladder outlet obstruction; despite restoring amniotic fluid, renal outcomes are often compromised.
Balloon valvuloplasty for aortic stenosis remains an unproven therapeutic innovation aimed at preventing progression to hypoplastic left heart syndrome.
Fetoscopic surgery has proven safe and effective in treating twin–twin transfusion syndrome as well as other conditions such as amniotic band syndrome.
Intrafetal radiofrequency ablation has been shown to have fewer complications and better survival than fetoscopic cord occlusion in Twin Reversed Arterial Perfusion (TRAP).
Open fetal surgery is an option in rare cases for hydropic CPAM, sacrococcygeal teratoma (SCT), pericardial teratoma, and—depending on results of the MOMS trial—meningomyelocele (MMC).
EXIT procedures are indicated for the management of compromised airways due to cervical teratoma, CHAOS, intrathoracic mass, and severe micrognathia.
EXIT-to-ECMO may be beneficial in some cases of CDH or hypoplastic left heart syndrome with restrictive or intact atrial system.
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Prenatal diagnosis has become increasingly sophisticated, and technologic advances have enhanced not only our diagnostic abilities, but also our understanding of the natural history of lesions detected in the prenatal period. Invasive therapies have developed as a consequence of our expanded understanding of the natural history and pathophysiology of structural anomalies (Garmel and D’Alton, 1993; Adzick and Harrison, 1994b). Despite rapid progress in prenatal diagnosis in the 1960s and 1970s, few invasive therapies were considered, much less employed (Adamsons, 1966). If a fetal malformation was made prenatally, parents had only two alternatives: pregnancy termination (if the diagnosis was made prior to 24 weeks of gestation) or continuing to term (Harrison et al., 1981b). An additional option is arranging for delivery at a tertiary care facility where appropriate pediatric specialists would be available to immediately treat the newborn with a congenital anomaly. As the natural history of many prenatally diagnosed anomalies became better understood, early delivery was recognized as an option to avoid the continuing damage caused by the anomaly in utero (Adzick and Harrison, 1994a,b). Today there are more alternatives. In this chapter we describe the treatment options available, how they were developed, and new therapies that may be available in the future.
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FETAL SHUNTING PROCEDURES
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A new era in invasive fetal therapy began in the early 1980s, when several independent groups introduced shunting procedures for hydrocephalus and hydronephrosis (Clewell et al., 1982; Frigoletto et al., 1982; Golbus et al., 1982). These first few cases represented an extension of invasive fetal therapy from simple intrauterine blood transfusion for a medical illness to the first attempts at in utero treatment of structural anomalies ...