Fetoscopy In-Brief with Dr. Jose Peiro
With Dr. Jose Peiro · hosted by Dr. Em Gootee or Todd Ponsky · StayCurrentMD
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What the experts said
Fetoscopy is the most important and most promising technique for the future in fetal surgery.
In twin-to-twin transfusion syndrome, one twin transfers more blood to the other rather than balanced exchange, causing the donor to become dehydrated and stop urinating.
TTTS stage 1 is defined by amniotic fluid more than 8 cm around one twin and less than 2 cm around the other.
TTTS stage 2 is defined by the donor twin's bladder not being visible or not filling with urine during ultrasound.
TTTS stage 3 is defined by abnormal Doppler findings indicating one or both babies are sick.
TTTS stage 4 is defined by one baby being very sick and hydropic with signs of heart failure.
For TTTS treatment, surgeons use a fetoscope to visualize the placental surface, map vessels crossing between twins, and photocoagulate these connections.
Cincinnati Children's center performed more than 1000 evaluations and more than 1200 laser procedures for TTTS, representing one of the biggest series worldwide.
Dr. Peiro's team developed a fetoscopic laser release model for amniotic bands in fetal lambs in Barcelona and transferred this technique to humans.
For amniotic band syndrome, the survival rate is 94%.
Posterior urethral valves generate lower urinary tract obstruction and large bladders visible on fetal MRI.
Amniotic shunts for fetal bladder obstruction often migrate and dislodge, sometimes requiring 2 or 3 placements.
Fetoscopy allows direct visualization to diagnose urethral valves versus urethral atresia from inside the fetal bladder.
Laser ablation of urethral valves can be performed when the angle is favorable, or a transurethral catheter can be placed, or both techniques combined to achieve bladder voiding and preserve amniotic fluid for lung development.
In congenital diaphragmatic hernia, abdominal organs including bowel and liver herniate into the chest, compressing the lung and causing cessation of normal lung development.
CDH babies have severe problems breathing, ventilating, and oxygenating after birth due to pulmonary hypoplasia.
Even with the best neonatology care, high-frequency ventilation, and ECMO, some CDH babies still die from severe pulmonary hypoplasia.
Blocking the fetal trachea maintains lung fluid production, and this lung fluid is essential for lung growth in utero.
Proteomic analysis revealed a large number of proteins and growth factors involved in lung development, with proteins enhancing cell proliferation being most important, particularly through AKT and WNT signaling pathways.
Patient selection for fetal tracheal occlusion uses prenatal ultrasound and fetal MRI to calculate lung area and the observed-to-expected lung-to-head ratio.
For fetal tracheal occlusion, a fetoscope is introduced through the fetal mouth into the trachea and a detachable 7-millimeter balloon is deployed.
Only one company produces the balloon used for fetal tracheal occlusion.
Fetal position is critical for tracheal occlusion; if position is unfavorable, time must be spent performing fetal version to achieve proper tracheal access.
The tracheal occlusion balloon is left in place for 6 to 8 weeks.
European experience with more than 200 tracheal occlusion cases showed survival improvement in severe CDH from 8% to 55%.
The goal of tracheal occlusion is to produce better (not normal) lungs to avoid high-frequency ventilation, ECMO, and significant pulmonary hypertension, enabling earlier discharge home.
Future fetal surgery innovation should include repair of severe cleft palate and hydrocephalus.
Stem cell therapy and tissue engineering will be very important in the future of fetal surgery.
Cincinnati Children's has the nation's highest volume fetoscopic center.
In most fetal surgery cases, surgeons can only improve the patient's condition rather than completely fix the problem.
In TTTS stage 1, twins are often more than 20% different in size.
TTTS stage 5 is defined by one or both twins having passed away from severe TTTS.
YAG laser is used for photocoagulation in fetoscopic TTTS treatment.
For TTTS stages 1-3, survival rate is 92% for at least one twin and 75% for both twins.
For TTTS stage 4, survival rate is 91% for at least one twin and 70% for both twins.
Amniotic band syndrome occurs when fibrous bands of the amniotic sac get tangled around the developing fetus, mostly affecting extremities, and rarely wrapping around the head or umbilical cord.
Cincinnati Children's performed more than 50 evaluations and 25 surgeries for amniotic band syndrome, mostly around 23 weeks gestation.
Dr. Peiro's team created a tracheal occlusion model in fetal lambs and performed proteomic profiling of intrapulmonary fluid.
A lung-to-head ratio of 25% or less of expected indicates severe or extremely severe CDH cases with very low survival.
At Cincinnati Children's, including ECMO support, CDH survival rates improved from 40% to 85% with tracheal occlusion.