Fetoscopic Laser Photocoagulation in Management of Vasa Previa

Pregnancy Complications Clinical Trial

— FLUMEN  

Official title:

Fetoscopic Laser Photocoagulation in Management of Vasa Previa - FLUMEN Study

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06290232
• Other study ID #: IRB-P00044498
• Status: Not yet recruiting
• Phase: N/A
• Start date: August 1, 2024
• Est. completion date: March 31, 2028

Study information

• Verified date: June 2024
• Source: Boston Children's Hospital
• Contact: Brittany E Gudanowski
• Phone: 617-919-6658
• Email: Brittany.Gudanowski[@]childrens.harvard.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

In this research study, the investigators want to learn more about the safety and effectiveness of a fetal surgery, known as fetoscopic laser photocoagulation (FLP), for the treatment of a pregnancy condition called vasa previa (VP). Vasa previa is a pregnancy complication that happens when blood vessels from the fetus grow over the entrance to the womb. In a VP pregnancy, natural vaginal birth is deadly for the baby in more than half of cases due to the bursting of VP vessels and severe blood loss. Currently, VP patients are recommended to be closely monitored and often hospitalized once they reach the third trimester of pregnancy. An early delivery by C-section would typically be performed in order to avoid breaking the exposed fetal vessels.

Fetoscopic laser photocoagulation is a minimally invasive surgery in the womb to remove or correct abnormal blood vessels and tissues. In the FLP procedure, the surgeon uses a fetoscope (a tiny telescope) and a laser device to seal off unprotected vessels. While this surgery has been used to treat other pregnancy conditions, it has not yet been proven to be safe and/or effective for the treatment of vasa previa. This treatment aims to eliminate the VP, and, if successful, may have the potential to minimize the risk of bleeding, thereby enabling patients to avoid long hospitalization before delivery. This procedure may enable VP patients to have a vaginal delivery instead of C-section.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 20
• Est. completion date: March 31, 2028
• Est. primary completion date: August 1, 2027
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years to 55 Years

Eligibility

Inclusion Criteria:

• Pregnant patient

• Singleton pregnancy

• Confirmed diagnosis of vasa previa, defined as unprotected fetal vessels running through the membranes at or within 5cm of the internal cervical os. Diagnosis must be confirmed after 26w0d, and before 32w5d

• Able to undergo intervention during 30w0d to 32w6d

• Type II vasa previa in which one placental lobe is considered to be accessory, defined as constituting less than 20% of the total placental mass seen on MRI and US imaging

• Type II vasa previa in which multiple bridging vessels connect the two placental lobes (=4 vessels), and only 1-2 vessel(s) run through or within 5cm of the internal cervical os

• Patient is eligible to undergo anesthesia

• Patient and biological father of the fetus (if available) are able to provide signed informed consent

Exclusion Criteria:

• Gestational age at referral higher than 32w6d

• Multiple pregnancy

• Vasa previa types I and III

• Type II vasa previa in which the accessory lobe constitutes more than 20% of the total placental mass, as determined by the fetal surgeon during diagnostic fetoscopy

• Type II vasa previa in which all of the bridging vessels between placental lobes are running over the internal cervical os

• Fetal growth restriction, defined as estimated fetal weight or abdominal circumference less than the 10th percentile for gestational age

• Abnormal fetal brain MRI, including delayed maturation, hemorrhage, arterial ischemic injury, abnormal ventricular size, or any congenital anomalies

• Allergy or previous adverse reaction to ancillary medications with no available alternative

• Preterm contractions and PPROM before surgery

• Preeclampsia or uterine anomaly during the current pregnancy

• Placenta previa, low-lying placenta, placenta accreta spectrum disorder

• Suspicion of major recognized congenital syndrome on ultrasound or MRI that is not compatible with postnatal life

• Maternal pre-pregnancy BMI >40

• Active hepatitis B, hepatitis C, or HIV infection

• High risk for congenital fetal bleeding disorders

• Unreliable pregnancy dating due to an irregular menstrual cycle/uncertain last menstrual period with no confirmed dating from first trimester ultrasound

• The surgeon determines that the procedure is not feasible for any other reason after diagnostic fetoscopy

Related Conditions & MeSH terms

• Maternal; Procedure
• Pregnancy Complications
• Vasa Previa

Intervention

Device:
• Fetoscopic Laser Photocoagulation
Pregnant patients diagnosed with type II vasa previa will undergo fetoscopic laser photocoagulation of the involved fetal vessels. FLP will be performed laparoscopically using a fetoscope (tiny telescope) and a laser device inside of the womb. This procedure will be completed at 30w0d to 32w6d gestational age.

Locations

Country	Name	City	State
United States	Boston Children's Hospital	Boston	Massachusetts

Sponsors (1)

Lead Sponsor	Collaborator
Boston Children's Hospital

Country where clinical trial is conducted

United States, 

References & Publications (58)

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* Note: There are 58 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mode of delivery	The type of delivery, categorized as vaginal, assisted vaginal, or cesarean section.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Primary	Gestational age at delivery	The duration of pregnancy, measured in completed [weeks + days] from the first day of the last menstrual period (in individuals with regular menses and reliable dating) or determined through first-trimester ultrasound using fetal biometric measurements.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Primary	Successful visualization and mapping of vasa previa	Confirmation by the performing surgeon that the visualization and mapping of vasa previa by diagnostic fetoscopy matches imaging from US and MRI.	When the last (20th) participant undergoes FLP surgery, about 3 years from study start date.
Primary	The rate of successful coagulation of the vasa previa - intraoperative imaging	Confirmation of the complete coagulation of the vasa previa including the absence of blood flow in involved vessels. This will be measured in the OR directly after FLP surgery by ultrasound.	When the last (20th) participant undergoes FLP surgery, about 3 years from study start date.
Primary	The rate of successful coagulation of the vasa previa - postoperative imaging	Confirmation of the complete coagulation of the vasa previa including the absence of blood flow in involved vessels. This will be measured 2 weeks post-surgery by ultrasound and MRI.	Two weeks after the last (20th) participant undergoes FLP surgery, about 3 years from study start date.
Primary	The rate of successful coagulation of the vasa previa - pathology	Confirmation of the complete coagulation of the vasa previa including the absence of blood flow in involved vessels. This will be measured after delivery during placental analysis by pathology.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Primary	Placental function	Successful maintenance of placental function after surgery. This will be measured by MRI 2 weeks after surgery.	Two weeks after the last (20th) participant undergoes FLP surgery, about 3 years from study start date.
Secondary	GA at hospital admission	The gestational age at hospital admission before birth.	When the last (20th) participant is admitted to the hospital, a little less than 3 years from study start date
Secondary	Duration of hospital stay	The length of hospital stay for the pregnant person will be recorded, from the time of admission to discharge.	When the last (20th) participant is discharged from the hospital, a little more than 3 years from study start date
Secondary	Cause for hospital admission	The reason for hospital admission before birth will be recorded.	When the last (20th) participant is admitted to the hospital, a little less than 3 years from study start date
Secondary	The rate of spontaneous preterm labor	The incidence of labor occurring naturally before 37 completed weeks of pregnancy with regular uterine contractions and progressive cervical dilation in the absence of medical or obstetric intervention.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	The rate of preterm premature rupture of membranes (PPROM)	The incidence of PPROM, defined as rupture of the amniotic sac after FLP surgery and before 37 completed weeks of pregnancy.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	The rate of placental abruption	The rate of separation of the placenta from the uterine wall after FLP surgery and before delivery.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	The rate of chorioamnionitis	The rate of infection of the fetal membranes and amniotic fluid after FLP surgery and before delivery.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	The rate of chorioamniotic separation	The rate of separation of the amniotic and chorionic membranes after FLP surgery and before delivery.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	Interval from procedure to delivery	The length of time from FLP surgery to delivery will be recorded in weeks and days.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	The rate of fetal growth restriction	The rate of fetal growth restriction, defined as an estimated fetal weight or abdominal circumference below the 10th percentile for gestational age, at any time after FLP surgery up to delivery.	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	Fetal brain structure	Normal or abnormal fetal brain structure will be assessed by MRI 2 weeks after surgery.	Two weeks after the last (20th) participant undergoes FLP surgery, about 3 years from study start date
Secondary	The rate of NICU admission	The rate of NICU admission after birth will be recorded	When the last (20th) participant reaches delivery, a little more than 3 years from study start date
Secondary	NICU length of stay	The number of days that the baby spends in the NICU after birth.	When the last baby is discharged from the NICU, a little more than 3 years from study start date
Secondary	Short term neonatal morbidity	The rate of short term morbidity during the first 30 days of life or until hospital discharge, whichever is latest. Short-term morbidity includes neurological problems, gastrointestinal problems, respiratory problems, infections, and other problems associated with prematurity including but not limited to: necrotizing enterocolitis, bronchopulmonary dysplasia, respiratory distress syndrome, neonatal sepsis, neonatal intensive care unit admission and need for extracorporeal membrane oxygenation (ECMO).	When the last baby is discharged from the hospital, a little more than 3 years from study start date
Secondary	Neonatal survival	The rate of neonates surviving to 30 days of age, or hospital discharge, whichever is latest.	When the last baby is discharged from the hospital, a little more than 3 years from study start date
Secondary	Maternal mental health score	The Postpartum Depression Screening Scale (PDSS) - Antenatal Version will be used to assess and compare the levels of depression and anxiety before and after FLP surgery. This assessment will be given once before surgery, and once again 4-8 weeks later (at least 2 weeks after surgery).	Two weeks after the last (20th) participant undergoes FLP surgery, about 3 years from study start date
Secondary	Postnatal examination of the placenta	The placenta will be examined for disrupted or ruptured vessels after dye staining. Secondary changes in the accessory lobe will also be checked, which are features resulting from cessation of blood supply due to prior ablation. These could include fibrin deposition, evidence of hypoxia in the chorionic villi, eventual necrosis, and parenchymal atrophy	When the last (20th) participant reaches delivery, a little more than 3 years from study start date