(95) Implications of repeat fetoscopic laser surgery in Twin Twin Transfusion Syndrome

Thursday, February 9, 2023

10:30 AM – 12:00 PM

Objective: Fetoscopic Laser Surgery (FLS) is the standard treatment for Twin Twin Transfusion Syndrome (TTTS). Post-laser Twin Anemia Polycythemia Sequence (TAPS) and recurrent TTTS are rare but serious complications of FLS that can be treated with repeat fetoscopic laser (rFLS). We sought to evaluate the implications of rFLS by comparing outcomes to patients who were cured with a single FLS (sFLS).

Study Design: We conducted a matched analysis to evaluate gestational age (GA) at delivery for equivalence between rFLS and sFLS. Secondarily, we assessed equivalence in birth survivors. Due to the small number of patients who required rFLS, each patient was matched to 3 sFLS patients (matching ratio 1:3) for TTTS stage, co-existing selective fetal growth restriction, and GA at first laser ( < 18, 18-23.9, and >24). Equivalence was assessed using two 1-sided tests (TOST) for GA at delivery and by the RISKDIFF option within Fischer's Exact test for proportion of birth survivors (BS).

Results: 11 patients underwent rFLS for recurrent TTTS (n=1) or post-laser TAPS (n=10). Repeat FLS and sFLS patients were not significantly different in maternal age, race, BMI, pre-operative cervical length, prior live birth, or history of preterm birth. There was no significant difference in GA at birth (31.7 vs 30.91 weeks, p=0.58) or in the number of birth survivors (p=0.15 (Table)). GA at delivery was not equivalent using an equivalence bound of 2 weeks but there was trend level equivalence with a bound of 3 weeks (p=0.20 and p=0.06, respectively). The proportion of double BS was statistically equivalent between groups (Risk Difference: -0.15, 95% CI [-0.50, -0.11], p=0.23).

Conclusion: Patients requiring rFLS had equivalent double twin survival compared to patients whose TTTS was cured after sFLS. Although mean GA at delivery did not reach equivalence and thusly warrants further exploration in a larger cohort, this data may be helpful for patients who are faced with needing treatment for recurrent disease.

Primary & Presenting Author(s)

Abby Birk, BA (she/her/hers)
Clinical Research Assistant
Johns Hopkins Center for Fetal Therapy
Baltimore, Maryland, United States

Coauthor(s)

CS
Camille Shantz, N/A
Johns Hopkins University
Baltimore, Maryland, United States
JJ
Jessamine Jin, N/A
Johns Hopkins University
Baltimore, Maryland, United States
KV
Kristin Voegtline, PhD
Johns Hopkins School of Medicine
Baltimore, Maryland, United States
SO
Sarah Olson, MPH
Johns Hopkins School of Medicine
Baltimore, Maryland, United States
MK
Michelle Kush, MD
Johns Hopkins University
Baltimore, Maryland, United States
Ahmet A. Baschat, MBBCH, MD (he/him/his)
Director
Johns Hopkins Center for Fetal Therapy
Baltimore, Maryland, United States
Jena L. Miller, MD (she/her/hers)
Assistant Professor
Johns Hopkins Center for Fetal Therapy
Baltimore, Maryland, United States
MR
Mara Rosner, MD, MPH
Assistant Professor
Johns Hopkins Center for Fetal Therapy
Baltimore, Maryland, United States