Twin to Twin Transfusion SyndromeNCT06084247
The Efficacy of the KARL STORZ Curved Fetoscope and Straight Fetoscope for Laser Photocoagulation of Placental Anastomoses
A study testing Curved KARL STORZ fetoscope and Conventional Scopes in people with Twin to Twin Transfusion Syndrome, run by Jimmy Espinoza at 1 site in United States.
Trial summary
The purpose of this study is to evaluate the efficacy of KARL STORZ curved fetoscope (11508AAK) and its straight version (11506AAK) for laser photocoagulation of placental anastomoses in patients with an anterior placenta and Twin to Twin Transfusion Syndrome (TTTS). Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Twin to Twin Transfusion Syndrome
- What is being tested?
- Curved KARL STORZ fetoscope and Conventional Scopes
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 160 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Sep 2025to 1 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- pregnancy
- The patient fulfills the criteria for laser photocoagulation of placental anastomoses based on the standard of care
- fetal diagnosis of twin-to-twin transfusion syndrome
- Anterior placenta
- The patient provides signed informed consent that details the maternal and fetal risks involved with the procedure
Who cannot join
- Contraindication to abdominal surgery, fetoscopic surgery, or general anesthesia
- Allergy or previous adverse reaction to a study medication specified in this protocol
- The patient does not fulfill the conventional criteria to undergo in-utero surgery, which is specific for each surgery
- Preterm labor, preeclampsia, or a uterine anomaly (e.g., large fibroid tumor) that is unavoidable during surgery in the index pregnancy
- Fetal aneuploidy, genomic variants of known significance if an amniocentesis has been performed, other major fetal anomalies or disorders that may impact the fetal/neonatal survival, or a known syndromic mutation
- Suspicion of a major recognized syndrome by ultrasound or MRI
- Maternal BMI >40 kg/m2
- High risk for fetal hemophilia
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
The University of Texas Health Science Center at Houston
Houston, Texas, 77030
Jimmy Espinoza, MD,MSc,FACOG, (713) 500-5859, Jimmy.Espinoza@uth.tmc.edu
Elisa Garcia, 713-500-6347, Elisa.I.Garcia@uth.tmc.edu
About this study
Official title: An Open Label Randomized-control Study on the Efficacy of the KARL STORZ Curved Fetoscope (11508aak) and Its Straight Version (11506aak) for Laser Photocoagulation of Placental Anastomoses
The purpose of this study is to evaluate the efficacy of KARL STORZ curved fetoscope (11508AAK) and its straight version (11506AAK) for laser photocoagulation of placental anastomoses in patients with an anterior placenta and Twin to Twin Transfusion Syndrome (TTTS).
- Conditions
- Twin to Twin Transfusion Syndrome
- Being tested
- Curved KARL STORZ fetoscope, Conventional Scopes
- Medical subject headings
- Fetofetal Transfusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Curved KARL STORZ fetoscopeDevice
The KARLZ STORZ curved scope is used to see the inside of a pregnant person's uterus during minimally invasive surgery, similar to conventional scopes. The curved scope is rounded and thought to help visualize the anterior placenta because of its position on the uterus.
Conventional ScopesDevice
The conventional scopes are regularly used during laser photocoagulation of placental anastomoses.
| Study group | Role | What they receive |
|---|---|---|
| KARL STORZ Curved Scope | Experimental | Not described Receives: Device: Curved KARL STORZ fetoscope |
| Conventional scopes | Active comparator | Not described Receives: Device: Conventional Scopes |
What is being measured
The primary outcome is the main question the study is designed to answer.
Operative time in minutes
Time from from operative cannula insertion until it is removed
Measured: during surgery
Secondary outcomes (12)
Number of Participants that have a gestational age of less than 37 weeks
Measured: at time of delivery (about 20 weeks from surgery)
Number of times additional fetoscopes are entered into the amniotic cavity to confirm completion of the in-utero intervention
Measured: end of surgery (about 60 minutes after start of surgery)
Total number of procedures with completion of the laser ablation
Measured: end of surgery (about 60 minutes after start of surgery)
Improved visualization as assessed by the Likert scale
This is reported categorically as strongly disagree, disagree, neither agree not disagree, agree and strongly agree. This is not a validated scale and does not have an official title. The minimum value is strongly disagree and the maximum value is strongly agree. Higher scores mean better outcomes.
Measured: end of surgery (about 60 minutes after start of surgery)
Improved angle for laser visualization as assessed by the Likert scale
This is reported categorically as strongly disagree, disagree, neither agree not disagree, agree and strongly agree
Measured: end of surgery (about 60 minutes after start of surgery)
Total number of fetuses alive, after the laser photocoagulation procedure
Measured: at discharge from hospital (about 24 hours after surgery)
Total number of maternal patients that present with morbidity
Measured: at discharge from hospital (about 24 hours after surgery)
Total number of patients that have maternal and/or fetal perioperative complications
Measured: end of surgery (about 60 minutes after start of surgery)
The number of participants that develop twin-anemia-polycythemia sequence (TAPS)
Measured: end of surgery (about 60 minutes after start of surgery)
Number of live births
Measured: at time of delivery (about 20 weeks from surgery)
Number of neonates with a short-term morbidity
Measured: from birth until hospital discharge
Infant development score using the Ages & Stages Questionnaires, Third Edition (ASQ-3)
Scored items on ASQ-3 address 5 areas of child development: communication, gross motor, Fine motor, problem solving, and personal-social and each of these have 6 questions each and is scored as yes( 10 points), sometimes (5 points) and not yet (0 points)-the total score is calculated for each area and scores should fall between 0-60, and a higher score indicates more development.
There is a 9 item overall developmental section that is answered categorically as yes or no answer
Measured: 24 months of age
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Oct 2023
- Study start1 Sep 2025 (estimated)
- Primary completion1 Nov 2026 (estimated)
- Study completion1 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Twin to Twin Transfusion SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 160 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jimmy Espinoza
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Jimmy Espinoza, The University of Texas Health Science Center, Houston
- Investigators
- Jimmy Espinoza, MD, MSc,FACOG, Principal investigator, The University of Texas Health Science Center, Houston
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06084247
- Sponsor's protocol ID
- HSC-MS-23-0622
- Status last verified
- Aug 2025
- First submitted
- 10 Oct 2023
- Last updated
- 14 Aug 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open Label Randomized-control Study on the Efficacy of the KARL STORZ Curved Fetoscope (11508aak) and Its Straight Version (11506aak) for Laser Photocoagulation of Placental Anastomoses
- ClinicalTrials.gov ID
- NCT06084247
- Acronym / sponsor ID
- HSC-MS-23-0622
- Conditions
- Twin to Twin Transfusion Syndrome
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 160 participants (estimated)
- Lead sponsor
- Jimmy EspinozaUniversity, hospital or other
- Study start
- 1 Sep 2025 (estimated)
- Primary completion
- 1 Nov 2026 (estimated)
- Study completion
- 1 Dec 2027 (estimated)
- First posted
- 16 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the efficacy of KARL STORZ curved fetoscope (11508AAK) and its straight version (11506AAK) for laser photocoagulation of placental anastomoses in patients with an anterior placenta and Twin to Twin Transfusion Syndrome (TTTS).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| KARL STORZ Curved Scope | Experimental | Device: Curved KARL STORZ fetoscope |
| Conventional scopes | Active comparator | Device: Conventional Scopes |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- pregnancy
- The patient fulfills the criteria for laser photocoagulation of placental anastomoses based on the standard of care
- fetal diagnosis of twin-to-twin transfusion syndrome
- Anterior placenta
- The patient provides signed informed consent that details the maternal and fetal risks involved with the procedure
Key exclusion criteria (8 listed)
- Contraindication to abdominal surgery, fetoscopic surgery, or general anesthesia
- Allergy or previous adverse reaction to a study medication specified in this protocol
- The patient does not fulfill the conventional criteria to undergo in-utero surgery, which is specific for each surgery
- Preterm labor, preeclampsia, or a uterine anomaly (e.g., large fibroid tumor) that is unavoidable during surgery in the index pregnancy
- Fetal aneuploidy, genomic variants of known significance if an amniocentesis has been performed, other major fetal anomalies or disorders that may impact the fetal/neonatal survival, or a known syndromic mutation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Curved KARL STORZ fetoscopeThe KARLZ STORZ curved scope is used to see the inside of a pregnant person's uterus during minimally invasive surgery, similar to conventional scopes. The curved scope is rounded and thought to help visualize the anterior placenta because of its position on the uterus. | Device | KARL STORZ Curved Scope |
| Conventional ScopesThe conventional scopes are regularly used during laser photocoagulation of placental anastomoses. | Device | Conventional scopes |
Primary outcome
Operative time in minutes
Time frame: during surgery
Time from from operative cannula insertion until it is removed
12 secondary outcomes
Number of Participants that have a gestational age of less than 37 weeks
Time frame: at time of delivery (about 20 weeks from surgery)
Number of times additional fetoscopes are entered into the amniotic cavity to confirm completion of the in-utero intervention
Time frame: end of surgery (about 60 minutes after start of surgery)
Total number of procedures with completion of the laser ablation
Time frame: end of surgery (about 60 minutes after start of surgery)
Improved visualization as assessed by the Likert scale
Time frame: end of surgery (about 60 minutes after start of surgery)
Improved angle for laser visualization as assessed by the Likert scale
Time frame: end of surgery (about 60 minutes after start of surgery)
Total number of fetuses alive, after the laser photocoagulation procedure
Time frame: at discharge from hospital (about 24 hours after surgery)
Total number of maternal patients that present with morbidity
Time frame: at discharge from hospital (about 24 hours after surgery)
Total number of patients that have maternal and/or fetal perioperative complications
Time frame: end of surgery (about 60 minutes after start of surgery)
The number of participants that develop twin-anemia-polycythemia sequence (TAPS)
Time frame: end of surgery (about 60 minutes after start of surgery)
Number of live births
Time frame: at time of delivery (about 20 weeks from surgery)
Number of neonates with a short-term morbidity
Time frame: from birth until hospital discharge
Infant development score using the Ages & Stages Questionnaires, Third Edition (ASQ-3)
Time frame: 24 months of age
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2025.
- Individual participant dataSharing planned: No
Related trials for Twin to Twin Transfusion Syndrome
Active, not recruitingObservational study
Database of Monochorionic Pregnancies
Monochorionic Diamniotic Placenta, Monochorial Monoamniotic Placenta
Recruiting
The Effect of Uterine Entry In Fetoscopic Laser Photocoagulation for Twin-To-Twin Transfusion Syndrome
Twin to Twin Transfusion
Recruiting
Evaluation of Laparotomy With Trans-Amniotic Suture Placement in TTTS Surgery
Twin to Twin Transfusion Syndrome, Twin Anemia-Polycythemia Sequence
Recruiting
A Prospective Study on the Role of Karl Storz Curved and Straight Fetoscopes (11508AAK and 11506AAK) for Fetoscopic Intrauterine Procedures
Fetal Conditions, Maternal; Procedure
RecruitingObservational study
Multicenter Prospective Cohort Study of Twin Maternal-Child Dyads in China
Twin Pregnancy, Antepartum Condition or Complication, Twin to Twin Transfusion as Antepartum Condition
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jimmy Espinoza, MD, MSc,FACOG principal investigator
The University of Texas Health Science Center, Houston
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Curved KARL STORZ fetoscope and Conventional Scopes in people with Twin to Twin Transfusion Syndrome, run by Jimmy Espinoza at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 14 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jimmy Espinoza, MD, MSc,FACOG ((713) 500-5859, Jimmy.Espinoza@uth.tmc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Operative time in minutes (time frame: during surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Aug 2025.