Percutaneous laser ablation of fetal congenital cystic adenomatoid malformation: too little, too late?

OBJECTIVE: Congenital cystic adenomatoid malformation, type III (CCAM III) lesions are large, bulky tumors which can cause mediastinal shift, prevent normal pulmonary growth, and compress the esophagus, thus leading to complications of nonimmune hydrops, pulmonary hypoplasia and polyhydramnios. Because the mortality rate of untreated fetuses with CCAM and hydrops is high, early delivery or intrauterine resection of the enlarged pulmonary lobe (lobectomy) is indicated; however, open fetal resection of CCAM at less than 30 weeks is associated with perioperative mortality that approaches 40%, as well as the usual maternal and fetal morbidity of open fetal surgery. As an alternative, percutaneous laser ablation of a CCAM III lesion with hydrops was attempted. METHODS: A 30-year-old G3 P1011 with CCAM III in the left fetal hemithorax developed mediastinal shift, hydrops and polyhydramnios at 23 weeks' gestation. After pregnancy termination and open fetal resection were declined, an 18-gauge needle was placed into the fetal tumor percutaneously under real-time ultrasonographic guidance, using sterile technique with light sedation. A cleaved 400-microm Nd:YAG laser fiber was passed through the needle lumen, and using a power setting of 15 W, a total of 2,943 J of laser energy was delivered in pulses of 1.0 s at 0.2-second intervals over two sessions one week apart. RESULTS: Although tumor size decreased, the hydrops worsened and fetal death occurred. CONCLUSIONS: The fetus with CCAM complicated by hydrops is already so compromised by the advanced state of the disease that insufficient time is available for necrotic tissue reabsorption after minimally invasive therapy with laser energy. Until earlier markers for intervention are determined, percutaneous laser debulking of CCAM is unlikely to be successful.

Fetal acoustic stimulation as a possible adjunct to diagnostic obstetric ultrasound: a preliminary report.

Unfavorable fetal position during diagnostic obstetric ultrasound can interfere with visualization of certain structures, leading to prolonged or repeated examination. Fetal acoustic stimulation induces a fetal startle reflex and an increase in fetal movements. This report describes our experience with fetal acoustic stimulation to prompt fetal movement in an effort to improve fetal visualization. At gestational ages of 28 weeks or more a 94.1% success rate was noted, in 30 seconds or less in 70.6% of the cases. We conclude that fetal acoustic stimulation may be a valuable adjunct to diagnostic obstetric ultrasound.