A Prospective Study on the Role of Karl Storz Curved and Straight Fetoscopes (11508AAK and 11506AAK) for Fetoscopic Intrauterine Procedures

Overview

In this research study, the investigators want to learn more about the role of new innovative surgical devices, the Karl Storz Curved and Straight Fetoscopes for in-utero surgery. A fetoscope is like a small telescope that can see inside of the uterus (womb) during minimally invasive surgery. The curved scope is used for patients with an anterior placenta (front of uterus), while the straight scope is used for patients with a posterior placenta (back of uterus). The scopes will be used to assist in procedures involving fetoscopic laser photocoagulation (FLP), which is a minimally invasive surgery that uses a small camera (fetoscope) to locate abnormal blood vessel connections in the placenta and seal them off using laser energy. These fetoscopes will be utilized in the diagnosis and management of various fetal conditions that can arise during pregnancy. Outcome data will be reported in a descriptive statistical analysis. The investigators will assess the surgical outcomes, short and long-term morbidity, complications, and gestational age of participants in order to evaluate the benefit of using these devices.

Detailed description

The objective of this study is to evaluate the benefit of Karl Storz curved (11508AAK) and straight (11506AAK) fetoscopes for in-utero surgery. The investigators will assess the surgical outcomes, short and long-term morbidity, complications, and gestational age of participants who undergo intrauterine procedures with these devices. The scopes will be used to assist in intrauterine procedures across a variety of fetal conditions, such as TTTS (twin-twin transfusion syndrome), TAPS (twin anemia polycythemia sequence), sFGR (selective fetal growth restriction) or TRAP sequence (twin reversed arterial perfusion). Fetoscopic laser photocoagulation (FLP) can also be used during in-utero surgery to correct abnormal vessels in cases like chorioangioma or vasa previa. Other complex congenital anomalies may require fetal intervention or diagnostic fetoscopy using Storz scopes.

Improvements in the technique, experience and equipment have been associated with better maternal, fetal, and neonatal outcomes in fetal surgery. Smaller fetoscopes are associated with lower rates of premature delivery following FLP. New fetoscopes (11508AAK and 11506AAK) have the potential to improve visualization and the photocoagulation angle. Compared to alternative scopes, these Storz scopes provide a wider angle of view and are longer, enabling better reach to distant areas at the edge of the placenta, especially in cases of higher BMI, higher gestational age, and significant polyhydramnios.

This study is an un-blinded, non-randomized, single arm, feasibility study on a convenience cohort to demonstrate the role of a curved fetoscope device (11508AAK) or straight fetoscope device (11506AAK) among in-utero surgeries. Patients will be enrolled in a consecutive manner and all qualifying, patients who agreed to the use of the curved or straight fetoscopes will be enrolled in the study. Outcome data will be reported as a descriptive statistical analysis. The curved fetoscope (11508AAK) device will be used in monochorionic pregnancies with an anterior placenta requiring in-utero surgery, while the straight fetoscope (11506AAK) will be used in monochorionic pregnancies with a posterior placenta. This device is classified as a significant risk device because it is of substantial importance in diagnosing, curing, mitigating, or treating disease, or otherwise preventing impairment of human health and presents a potential for serious risk to the health, safety, or welfare of a subject.

Interventions

• Device Karl Storz Curved Scope
  The curved fetoscope (11508AAK) will be used to view target areas during in-utero procedures for patients with a placenta that sits at the front of the uterus. There are various fetal conditions that may require use of a fetoscope during minimally invasive surgery. These include the need to seal vessels in order to stop blood flow going in a specific direction during pregnancy, abnormal vessels that may need to be sealed, or to break down scar tissue, extra tissue attachments, or blockages.
• Device Karl Storz Straight Scope
  The straight fetoscope (11506AAK) will be used to view target areas during in-utero procedures for patients with a placenta that sits at the back of the uterus. There are various fetal conditions that may require use of a fetoscope during minimally invasive surgery. These include the need to seal vessels in order to stop blood flow going in a specific direction during pregnancy, abnormal vessels that may need to be sealed, or to break down scar tissue, extra tissue attachments, or blockages.

Primary outcome measures

• Rate of completed fetoscopic procedures [Time frame: 3 years from study start date]
• Fetal survival at birth [Time frame: When the last (50th) study participant reaches birth. Likely to be a bit more than 3 years from study start date.]

Secondary outcome measures (12)

• Successful visualization of all targeted vessels [Time frame: 3 years from study start date]
• Successful coagulation of all targeted vessels [Time frame: 3 years from study start date]
• The rate of preterm labor [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]
• The rate of preterm premature rupture of membranes (PPROM) [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]
• The rate of placental abruption [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]
• The rate of choriamniotic separation (CAS) [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]
• The rate of iatrogenic septostomy [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]
• The rate of completed Solomonizations [Time frame: 3 years from study start date]
• The rate of any perioperative complications (within 24 hours post-procedure) [Time frame: 24 hours after the last (50th) procedure using these fetoscopes. This will be a bit more than 3 years from study start date.]
• Fetal survival 48 hours post-procedure [Time frame: 24 hours after the last (50th) procedure using these fetoscopes. This will be a bit more than 3 years from study start date.]
• Rate of TAPS [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]
• Recurrence of TTTS [Time frame: When the last (50th) study participant reaches birth. This is likely to be a bit longer than 3 years from study start date.]

Eligibility criteria

Inclusion criteria

• Pregnant patient with a condition requiring in-utero surgery
• Patient must be eligible for anesthesia
• Patient and father of the fetus (if available) are able to provide signed informed consent

Exclusion criteria

• Allergy or previous adverse reaction to any ancillary medication specified in this protocol that has no alternative
• Preterm labor, preeclampsia, or uterine anomaly (e.g., large fibroid tumor) in the index pregnancy
• Suspicion of major recognized congenital syndrome on ultrasound or MRI that is not compatible with postnatal life
• Pre-pregnancy maternal BMI greater than 40
• High risk for fetal hemophilia
• Fetal aneuploidy or variants of known significance if an amniocentesis was performed
• Contraindication to abdominal surgery or fetoscopic surgery

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

United States · 1 center

• Boston Children's Hospital — Boston

Publications

• Petersen SG, Gibbons KS, Luks FI, Lewi L, Diemert A, Hecher K, Dickinson JE, Stirnemann JJ, Ville Y, Devlieger R, Gardener G, Deprest JA. The Impact of Entry Technique and Access Diameter on Prelabour Rupture of Membranes Following Primary Fetoscopic Laser Treatment for Twin-Twin Transfusion Syndrome. Fetal Diagn Ther. 2016;40(2):100-9. doi: 10.1159/000441915. Epub 2016 Apr 14. PMID 27073886
• Papanna R, Block-Abraham D, Mann LK, Buhimschi IA, Bebbington M, Garcia E, Kahlek N, Harman C, Johnson A, Baschat A, Moise KJ Jr. Risk factors associated with preterm delivery after fetoscopic laser ablation for twin-twin transfusion syndrome. Ultrasound Obstet Gynecol. 2014 Jan;43(1):48-53. doi: 10.1002/uog.13206. PMID 24013922
• Diehl W, Diemert A, Grasso D, Sehner S, Wegscheider K, Hecher K. Fetoscopic laser coagulation in 1020 pregnancies with twin-twin transfusion syndrome demonstrates improvement in double-twin survival rate. Ultrasound Obstet Gynecol. 2017 Dec;50(6):728-735. doi: 10.1002/uog.17520. PMID 28477345
• Senat MV, Deprest J, Boulvain M, Paupe A, Winer N, Ville Y. Endoscopic laser surgery versus serial amnioreduction for severe twin-to-twin transfusion syndrome. N Engl J Med. 2004 Jul 8;351(2):136-44. doi: 10.1056/NEJMoa032597. Epub 2004 Jul 6. PMID 15238624
• Deprest JA, Van Schoubroeck D, Van Ballaer PP, Flageole H, Van Assche FA, Vandenberghe K. Alternative technique for Nd: YAG laser coagulation in twin-to-twin transfusion syndrome with anterior placenta. Ultrasound Obstet Gynecol. 1998 May;11(5):347-52. doi: 10.1046/j.1469-0705.1998.11050347.x. PMID 9644775
• Middeldorp JM, Lopriore E, Sueters M, Klumper FJ, Kanhai HH, Vandenbussche FP, Oepkes D. Twin-to-twin transfusion syndrome after 26 weeks of gestation: is there a role for fetoscopic laser surgery? BJOG. 2007 Jun;114(6):694-8. doi: 10.1111/j.1471-0528.2007.01337.x. PMID 17516960
• Shamshirsaz AA, Javadian P, Ruano R, Haeri S, Sangi-Haghpeykar H, Lee TC, Molohon J, Cass DL, Salmanian B, Mollett L, Moaddab A, Espinosa J, Olutoye OO, Belfort MA. Comparison between laparoscopically assisted and standard fetoscopic laser ablation in patients with anterior and posterior placentation in twin-twin transfusion syndrome: a single center study. Prenat Diagn. 2015 Apr;35(4):376-81. doi PMID 25559783
• Krispin E, Nassr AA, Espinoza J, Donepudi R, Sun RC, Sanz-Cortes M, Mostafaei S, Belfort MA, Shamshirsaz AA. Outcomes of laparoscopy-assisted fetoscopic laser photocoagulation for twin-twin transfusion syndrome: An established alternative for inaccessible anterior placenta. Prenat Diagn. 2021 Nov;41(12):1582-1588. doi: 10.1002/pd.5955. Epub 2021 Oct 17. PMID 34658043

Identifiers

NCT: NCT06056635 · IRB-P00044063

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗