Fetoscopic Laser Surgery for Twin to Twin Transfusion Syndrome

Overseen By Elisa Garcia

Age: 18 - 65

Sex: Female

Trial Phase: Academic

Sponsor: Jimmy Espinoza

Disqualifiers: Preterm labor, Preeclampsia, Uterine anomaly, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests two types of fetoscopes, special instruments used during surgery, to treat Twin to Twin Transfusion Syndrome (TTTS). TTTS occurs when twins share blood unequally in the womb, and this study evaluates the effectiveness of the fetoscopes in stopping this condition with laser surgery. One fetoscope is curved, and the other is straight, and both are used to seal off shared blood vessels in the placenta. Women pregnant with twins, diagnosed with TTTS, and having an anterior placenta (placenta at the front of the uterus) might be suitable candidates for this study. As an unphased trial, this study provides a unique opportunity to contribute to innovative research that could improve outcomes for future pregnancies.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that these fetoscopes are safe for use in Twin to Twin Transfusion Syndrome?

Research has shown that using the KARL STORZ curved and straight fetoscopes for laser surgery in Twin to Twin Transfusion Syndrome (TTTS) is generally well-tolerated. In past studies, survival rates for twins treated with this surgery varied. Overall, both twins survived in 45% to 70% of cases, while at least one twin survived in 60% to 85% of cases.

However, some risks are involved. For example, there is an 11–14% chance of long-term developmental issues. Additionally, complications like early breaking of the water, which can lead to premature labor, are possible.

These findings suggest that while fetoscopic laser surgery can be effective, it comes with certain risks that should be considered. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about fetoscopic laser surgery for Twin to Twin Transfusion Syndrome (TTTS) because it offers a precise, minimally invasive way to treat this complex condition. Unlike traditional methods that may involve broader surgical interventions, this technique uses specialized fetoscopes, like the curved KARL STORZ fetoscope, allowing doctors to target and seal abnormal blood vessel connections between twins more accurately. This precision minimizes risks and could improve outcomes for both twins significantly. By refining the delivery method with advanced scopes, this approach aims to enhance safety and effectiveness compared to conventional surgical methods.

What evidence suggests that the KARL STORZ fetoscopes are effective for Twin to Twin Transfusion Syndrome?

Research has shown that fetoscopic laser surgery is a promising treatment for Twin to Twin Transfusion Syndrome (TTTS). Without treatment, TTTS poses a high risk of losing the babies, with rates reaching 70%–90%. Studies indicate that using a small camera called a fetoscope for laser surgery can significantly improve survival rates. Specifically, the overall survival of both twins treated this way ranges from 45% to 70%, while the survival of at least one twin ranges from 60% to 85%. In this trial, participants will receive treatment using either the curved KARL STORZ fetoscope or conventional scopes. The curved and straight KARL STORZ fetoscopes are specially designed to help seal blood vessels with a laser in patients with a front-positioned placenta. Early findings suggest these tools effectively improve outcomes for TTTS patients. ^{1 2 6 7 8}

Who Is on the Research Team?

Jimmy Espinoza, MD, MSc,FACOG

Principal Investigator

The University of Texas Health Science Center, Houston

Are You a Good Fit for This Trial?

This trial is for pregnant individuals diagnosed with Twin to Twin Transfusion Syndrome (TTTS) who have an anterior placenta and meet the standard criteria for laser photocoagulation. They must consent to the risks of fetoscopic surgery. Excluded are those with contraindications to abdominal or fetoscopic surgery, general anesthesia allergies, preterm labor, preeclampsia, significant uterine anomalies, fetal genetic abnormalities or syndromes, or a maternal BMI over 40.

Inclusion Criteria

Pregnancy

Anterior placenta

My unborn twins have been diagnosed with twin-to-twin transfusion syndrome.

Exclusion Criteria

High risk for fetal hemophilia

Suspicion of a major recognized syndrome by ultrasound or MRI

Allergy or previous adverse reaction to a study medication specified in this protocol

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo laser photocoagulation of placental anastomoses using either the curved or straight KARL STORZ fetoscope

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, including infant development assessment at 24 months

24 months

What Are the Treatments Tested in This Trial?

Interventions

• Curved KARL STORZ fetoscope
• Straight KARL STORZ fetoscope

Trial Overview The study compares two types of fetoscopes: KARL STORZ's curved (11508AAK) and straight (11506AAK) models in performing laser photocoagulation on the placenta in TTTS cases. The goal is to determine which scope design offers better outcomes during this delicate surgical procedure.

How Is the Trial Designed?

Group I: KARL STORZ Curved Scope Experimental Treatment 1 Intervention

Group II: Conventional scopes Active Control 1 Intervention

Who Is Running the Clinical Trial?

Jimmy Espinoza

Lead Sponsor

Trials

1

Recruited

160+

Published Research Related to This Trial

In a study of 19 twin pregnancies with severe twin-twin transfusion syndrome (TTTS), fetoscopic laser therapy using a 1.0 mm endoscope resulted in an overall survival rate of 52.6%, which is comparable to outcomes reported with larger endoscopes.

The therapy was more effective in stage III TTTS, with a survival rate of 61.1% for both twins, compared to 45.0% for stage IV, indicating that earlier intervention may lead to better outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective fetoscopic laser photocoagulation of superficial placental anastomoses for the treatment of severe twin-twin transfusion syndrome. Ruano, R., Brizot, Mde L., Liao, AW., et al.[2022]

In a study of 176 monochorionic twin pregnancies undergoing fetoscopic laser coagulation (FLC) for severe twin-to-twin transfusion syndrome (TTTS), the use of a 30 degrees fetoscope in challenging anterior placentation resulted in similar outcomes to the standard 0 degrees fetoscope used in more favorable placental locations.

Both groups had comparable survival rates for the fetuses, with 58.8% of study patients having both fetuses survive compared to 66.4% in the control group, indicating that the 30 degrees fetoscope is an effective alternative in difficult cases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Laser coagulation of placental anastomoses with a 30 degrees fetoscope in severe mid-trimester twin-twin transfusion syndrome with anterior placenta. Huber, A., Baschat, AA., Bregenzer, T., et al.[2008]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06084247

The Efficacy of the KARL STORZ Curved Fetoscope and ... The purpose of this study is to evaluate the efficacy of KARL STORZ curved fetoscope (11508AAK) and its straight version (11506AAK) for laser photocoagulation ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7930304/

Outcomes following selective fetoscopic laser ablation for ... Untreated TTTS carries a perinatal loss of 70%–90%.(2) It usually presents after 16 weeks of gestation and rarely after 26 weeks. TTTS results from chronic ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S1028455912001192

Short-term outcomes of fetoscopic laser surgery for severe ... Overall survival of TTTS treated by fetoscope had been reported to range from 45% to 70%, and survival of at least one twin ranges from 60% to 85% and higher [6] ...

4. withpower.com withpower.com/trial/phase-fetofetal-transfusion-10-2023-08a7f

Fetoscopic Laser Surgery for Twin to Twin Transfusion ... Both groups had comparable survival rates for the fetuses, with 58.8% of study patients having both fetuses survive compared to 66.4% in the control group, ...

5. obgyn.onlinelibrary.wiley.com obgyn.onlinelibrary.wiley.com/doi/full/10.1002/uog.13375

Fetoscopic laser coagulation for twin–twin transfusion ... The global prognosis of TTTS is poor in the absence of treatment; in a retrospective study of 136 cases managed expectantly up to 28 weeks' ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5969296/

Fetoscopic laser photocoagulation for twin–twin transfusion ... However, there is still an 11–14% risk of long‐term neurodevelopment impairment. The premature rupture of membranes that leads to preterm labor is a common ...

7. centerwatch.com centerwatch.com/clinical-trials/listings/NCT06056635/a-prospective-study-on-the-role-of-karl-storz-curved-and-straight-fetoscopes-11508aak-and-11506aak-for-fetoscopic-intrauterine-procedures

A Prospective Study on the Role of Karl Storz Curved and ... The objective of this study is to evaluate the benefit of Karl Storz curved (11508AAK) and straight (11506AAK) fetoscopes for in-utero surgery.

8. karger.com karger.com/fdt/article/50/2/106/836073/Flexible-Video-Fetoscopy-Feasibility-and-Outcomes

Flexible Video Fetoscopy: Feasibility and Outcomes of a ... Results: A total of 45 pregnancies with TTTS were treated with fetoscopic laser therapy during the 1-year study period. Twenty-one pregnancies ...