Flexible Video Fetoscopy: Feasibility and Outcomes of a Novel Modality for Laser Therapy in Twin-to-Twin Transfusion Syndrome Presenting with Inaccessible Anterior Placenta.

INTRODUCTION: Identification of intertwin anastomosis may be challenging during fetoscopy in cases with complete anterior placenta. The aim of this study was to describe the technique, feasibility, and outcomes of flexible video fetoscopy for laser coagulation in monochorionic (MC) twin pregnancies with twin-to-twin transfusion syndrome (TTTS) presenting with inaccessible anterior placenta. METHODS: From April 2021 to March 2022, a prospective cohort of consecutive MC twin pregnancies complicated with TTTS presenting with anterior placenta after 20 weeks was recruited. Cases with inaccessible anterior placenta during standard technique were converted into flexible video fetoscopy for completion of laser coagulation of placental anastomoses using a 270° flexible video endoscope through the same uterine port. Descriptive analysis includes feasibility, remaining anastomoses requiring laser photocoagulation, and perinatal outcomes. RESULTS: A total of 45 pregnancies with TTTS were treated with fetoscopic laser therapy during the 1-year study period. Twenty-one pregnancies presented with anterior placenta after 20 weeks, in which an inaccessible vascular equator was observed in 33.3% (7/21). Flexible video fetoscopy was successfully performed in all 7 cases at a median gestational age of 22+2 (20+0-27+1) weeks+days. Visualization of the entire placental surface, coagulation of selected vessels, and exploration of the entire vascular equator were achieved in all cases. Six cases (85.7%) required additional laser coagulation due to either vascular patency despite initial coagulation with conventional fetoscopy (1/6, 16.7%) and/or remaining noncoagulated anastomoses (5/6, 83.3%). Perinatal survival of at least one twin and both twins was achieved in 85.7% and 57.1%, respectively. DISCUSSION: Flexible video fetoscopy for completion of laser coagulation of placental anastomoses is feasible and represents a good option for TTTS cases presenting after 20 weeks with inaccessible anterior placenta.

Management of atypical cases of twin-to-twin transfusion syndrome.

Up to 20% of monochorionic diamniotic twin pregnancies can be complicated with twin-to-twin transfusion syndrome (TTTS). This complication is diagnosed by ultrasound demonstrating amniotic fluid discordance between both amniotic sacs, with polyhydramnios in the recipient's sac and oligohydramnios in the donor's, secondary to an imbalance in blood volume exchange between twins. Ultrasound evaluation of the amniotic fluid volume, bladder filling, and assessment of fetal Doppler parameters provide the basis for classification of TTTS, allowing severity assessment. The Quintero's staging system provides a standardized prenatal estimate on the risk of intrauterine fetal demise of one or both twins and the need for fetoscopic laser coagulation of placental vascular anastomoses or delivery depending on the gestational age. However, a proportion of TTTS cases may present without a linear progressive deterioration and no ultrasound signs of preceding staging, in rare situations, they arise even without amniotic fluid discordance. Thus, these unusual clinical presentations of TTTS have long been grouped into the category of atypical TTTS. In this review, we show the clues for diagnosis and management of different atypical cases of TTTS highlighting their underlying mechanism to improve the clinical understanding of such atypical situations, avoid misdiagnosis of TTTS, and allow a timely referral to a fetoscopic center.

Outcomes of late open fetal surgery for intrauterine spina bifida repair after 26 weeks. Should we extend the Management of Myelomeningocele Study time window?

OBJECTIVE: To evaluate maternal and perinatal outcomes of late open fetal repair for open spina bifida (OSB) between 26+0 -27+6  weeks. METHODS: A cohort of fetuses with OSB who underwent open surgery in two fetal surgery centers (Argentina and Mexico). Two groups were defined based on the gestational age (GA) at intervention: Management of Myelomeningocele Study (MOMS) time window group: GA 19+0 -25+6 , and late intervention group: GA 26+0 -27+6 . RESULTS: Intrauterine OSB repair was successfully performed in 140 cases, either before (n = 57) or after (n = 83) 26 weeks, at on average 25+0 (22+6 -25+6 ) and 26+5 (26+0 -27+6 ) weeks + days, respectively. There were no significant differences in the rate of premature rupture of membranes, chorioamnionitis, oligohydramnios, preterm delivery, perinatal death and maternal complications. The late intervention group showed a significantly lower surgical times (112.6 vs. 124.2 min, p = 0.01), lower interval between fetal surgery and delivery (7.9 vs. 9.2 weeks, p < 0.01) and similar rate of hydrocephalus requiring treatment (30.6% vs. 23.3%, p = 0.44) than the MOMS time window group. CONCLUSION: Late fetal surgery for OSB repair between 26+0 -27+6  weeks is feasible and was associated with similar outcomes than that performed before 26 weeks. These findings may allow an extension of the proposed time window for cases with late diagnosis or referral.

Twin-to-twin transfusion syndrome and coronavirus disease 2019: impact on diagnosis, referral, eligibility for fetoscopic laser therapy, and outcomes.

BACKGROUND: Because of the progressive nature of twin-to-twin transfusion syndrome, difficulties in healthcare access during the COVID-19 pandemic may lead to delayed diagnosis and referral to fetal surgery centers, which may have repercussions on outcomes. OBJECTIVE: This study aimed to assess the clinical impact of the COVID-19 pandemic on pregnancies complicated with twin-to-twin transfusion syndrome. STUDY DESIGN: A retrospective cohort study of consecutive monochorionic diamniotic twin pregnancies complicated with twin-to-twin transfusion syndrome evaluated in our national referral fetal surgery center at Queretaro, Mexico, for possible surgical fetoscopy was conducted. Maternal-fetal characteristics and perinatal outcomes of cases evaluated during the first year of the World Health Organization's COVID-19 pandemic declaration (March 11, 2020 to March 10, 2021) were retrospectively compared with outcomes of cases evaluated during the same period in the previous year (March 11, 2019 to March 10, 2020). RESULTS: Overall, 109 consecutive twin-to-twin transfusion syndrome cases were evaluated during the 2-year study period, 54 during the COVID-19 pandemic and 55 in the previous year. In the former group, a higher proportion of cases with fetal surveillance interval longer than 2 weeks (70.4% vs 47.3%; P=.01); twin-to-twin transfusion syndrome complications precluding laser therapy, such as intrauterine fetal demise, preterm rupture of membranes, or cervical dilatation with prolapsed amniotic membranes (18.5% vs 1.8%; P<.01); advanced twin-to-twin transfusion syndrome (53.7% vs 36.4%; P=.07); preoperative short cervix (25.9% vs 10.9%; P<.05); and lower overall perinatal survival (56.9% vs 80.0% [P=.01; at least 1 twin] and 39.2% vs 56.4% [P=.08; both twins], respectively) were observed. A significantly lower number of cases were selected for fetoscopic laser therapy during the pandemic (75.9% vs 92.7%; P=.01), with similar postoperative outcomes seen in both study periods. CONCLUSION: In pregnancies with twin-to-twin transfusion syndrome, the COVID-19 pandemic has shown an adverse impact involving suboptimal fetal surveillance, advanced stages at diagnosis, poorer survival rates, and higher number of complications that preclude fetoscopic laser therapy.

Impact of fetal endoscopic tracheal occlusion in fetuses with congenital diaphragmatic hernia and moderate lung hypoplasia.

OBJECTIVE: To assess the effect of Fetal Endoscopic Tracheal Occlusion (FETO) on neonatal survival in fetuses with left congenital diaphragmatic hernia (CDH) and moderate lung hypoplasia. STUDY DESIGN: CDH fetuses with moderate pulmonary hypoplasia (observed/expected lung area to head ratio between 26% and 35%, or between 36% and 45% with liver herniation) were prospectively recruited. Included patients were matched to a control group who were ineligible for FETO. Primary outcomes were survival at 28 days, at discharge, and at 6 months of age, respectively. RESULTS: 58 cases were recruited, 29 treated with FETO and 29 matched controls. Median gestational age (GA) at balloon placement and removal were 29.6 and 33.6 weeks, respectively. FETO group showed significantly lower GA at delivery (35.2 vs. 37.1 weeks, respectively, p < 0.01), higher survival at 28 days (51.7 vs. 24.1%, respectively, p = 0.03), at discharge (48.3 vs. 24.1%, respectively, p = 0.06), and at six months of age (41.4 vs. 24.1%, respectively, p = 0.16), and significantly lower length of ventilatory support (17.8 vs. 32.3 days, p = 0.01) and NICU stay (34.2 vs. 58.3 days, p = <0.01) compared to controls. CONCLUSION: FETO was associated with a non-significant increase in survival and significantly lower neonatal respiratory morbidity among CDH fetuses with moderate lung hypoplasia.

Prediction of neonatal survival according to lung-to-head ratio in fetuses with right congenital diaphragmatic hernia (CDH): A multicentre study from the Latin American CDH Study Group registry.

OBJECTIVE: To evaluate survival outcomes of fetuses with right sided congenital diaphragmatic hernia (CDH) treated in Latin American centres and to assess the utility of left lung area to predict neonatal survival. METHODS: A retrospective cohort including isolated right sided CDH cases managed expectantly during pregnancy in six tertiary centers from five Latin American countries. The utility of the observed/expected lung-to-head ratio (O/E-LHR) in predicting neonatal survival was assessed, and the best cut-off to predict prognosis was automatically selected by decision tree analysis. RESULTS: A total of 99 right sided CDH cases were recruited, 58 isolated fetuses were selected at a median gestational age of 26.2 weeks, showing an overall survival rate of 26.2%. A linear trend was observed between survival and the O/E-LHR, showing that at higher O/E-LHR, the greater probability of survival (r = 0.56, p < 0.001). O/E-LHR discriminates two groups with different survival outcomes: fetuses with an O/E-LHR ≥65% showed a significantly higher survival rate than those with an O/E-LHR <65% (81.8% vs. 15.6%, p < 0.01). CONCLUSIONS: Overall survival rate in right sided CDH is lower in Latin American countries. The severity category of pulmonary hypoplasia should be classified according to lung area and the survival rate in such population.

Fetoscopic urethral meatotomy in fetuses with lower urinary tract obstruction by congenital megalourethra.

BACKGROUND: To describe the perinatal outcomes of fetoscopic urethral meatotomy (FUM) in fetuses with lower urinary tract obstruction (LUTO) by congenital megalourethra. STUDY DESIGN: Between 2012 and 2020, 226 cases with LUTO were referred to our fetal surgery center in Queretaro, Mexico. We report the perinatal outcome of cases with LUTO by congenital megalourethra that were selected for FUM in an attempt to release the penile urethral obstruction. RESULTS: Congenital megalourethra was diagnosed in 10 cases (4.4%) but only 3 cases (30%) with obstructive megalourethra and megacystis were selected for fetal surgery. Fetoscopic urethral metatotomy was successfully performed in all three cases at a median gestational age (GA) of 21.4 (18.0-26.7) weeks and with a median surgical time of 27 (12-43) min. A resolution of urethral dilatation and subsequent reduction of the penile length and normalization of both the bladder size and amniotic fluid were observed in all cases. The median GA at delivery was 35.2 (range: 30.6-38.0) weeks. There were no fetal deaths but one neonatal death (33%) secondary to renal failure and preterm delivery. CONCLUSION: In fetuses with LUTO by congenital obstructive megalourethra, FUM is feasible and is associated with good perinatal outcomes.

Preoperative Cervical Length Predicts the Risk of Delivery within One Week after Pleuroamniotic Shunt in Fetuses with Severe Hydrothorax.

OBJECTIVE: The objective of this study was to assess the predictive performance of preoperative cervical length (CL) for delivery within 1 week after pleuroamniotic shunting (PAS) in fetuses with severe hydrothorax. METHODS: A prospective cohort of fetuses with severe hydrothorax referred to our fetal surgery center in Querétaro, Mexico from January 2012 to July 2020. Severe fetal hydrothorax was diagnosed as an accumulation of fluid within the fetal pleural space accompanied with severe bilateral lung compression, mediastinal shift, polyhydramnios, and/or hydrops. Transvaginal CL was measured immediately before PAS, and a short cervix was defined as that <25 mm. The interval from fetal intervention to delivery, prevalence of preterm prelabor rupture of membranes (PPROMs), and associations with delivery within the first week after PAS according to a short or a normal CL, were evaluated. RESULTS: Thirty-five pregnancies with severe fetal hydrothorax treated with PAS were evaluated. Median gestational age at PAS was (weeks + days) 31+2 (range, 26+0-36+1). Two (5.7%) and 7 (20.0%) cases delivered within the first 24 h and 1 week after PAS, respectively. Ten (28.6%) women had a short cervix before PAS, while 25 (71.4%) had normal preoperative CL. Women with a short cervix showed lower mean interval between fetal intervention and delivery (2.4 vs. 5.5 weeks, p = 0.01), and higher prevalence of PPROM (50 vs. 12%, p = 0.01), as compared to women with a nonshort cervix. Preoperative short cervix was associated with significantly higher risk of delivery within the first 24 h (20.0 vs. 0%, respectively, p < 0.05) and 1 week after PAS (50.0 vs. 8.0%, respectively, p < 0.01) compared with pregnancies with normal preoperative CL. CONCLUSION: In pregnancies with severe fetal hydrothorax candidates for pleuroamniotic shunt, identification of a short cervix before fetal intervention can predict delivery within 1 week after the surgical procedure.

Single Uterine Access for Bilateral Pleuroamniotic Shunting in Fetuses with Severe Hydrothorax by an Internal Rotational Maneuver: Feasibility and Outcomes between Successful and Failed Procedures.

OBJECTIVE: The objective of this study was to describe the feasibility of single percutaneous uterine access for bilateral pleuroamniotic shunting (PAS) in fetuses with severe hydrothorax by using an internal rotational maneuver and to compare perinatal outcomes between successful and failed procedures. METHODS: A prospective cohort of 25 fetuses with isolated bilateral hydrothorax and hydrops were referred to our fetal surgery center in Queretaro, Mexico during an 8-year period. Bilateral PAS was first attempted through a percutaneous single uterine access by internal rotation of the fetus, which was achieved by using the blunt tip of the same cannula, and in case of a failed procedure, a second uterine port was used to place the second shunt. The perinatal outcomes between successful (single uterine port) and failed (2 uterine ports) fetal procedures were compared. RESULTS: Placing of bilateral shunts through a percutaneous single uterine access was feasible in 15/25 (60%) cases. Overall, median GA at delivery was 35.2 weeks with a survival rate of 64.0% (16/25). Three cases were excluded due to shunt dislodgement, leaving a final population of 22 fetuses; 13/22 (59.1%) and 9/22 (40.9%) managed using 1 and 2 uterine ports, respectively. The group with bilateral PAS placement through a successful single uterine port showed a significantly higher GA at birth (36.5 vs. 32.8 weeks, p = 0.001), lower surgical time (11.0 vs. 19.0 min, p = 0.01), longer interval between fetal intervention and delivery (5.7 vs. 2.7 weeks, p = 0.01), lower risk of preterm delivery (46.2 vs. 100%, p < 0.01), and lower rate of perinatal death (15.4 vs. 55.6%, p < 0.05) than the failed procedures requiring 2 uterine ports. CONCLUSION: In fetuses with severe bilateral hydrothorax and hydrops, bilateral pleuroamniotic shunting through a successful single percutaneous uterine access is feasible in up to 60% of cases and is associated with better perinatal outcomes.

Open Fetal Microneurosurgery for Intrauterine Spina Bifida Repair.

OBJECTIVES: The aim of the study was to describe the feasibility of open fetal microneurosurgery for intrauterine spina bifida (SB) repair and to compare perinatal outcomes with cases managed using the classic open fetal surgery technique. METHODS: In this study, we selected a cohort of consecutive fetuses with isolated open SB referred to our fetal surgery center in Queretaro, Mexico, during a 3.5-year period (2016-2020). SB repair was performed by either classic open surgery (6- to 8-cm hysterotomy with leakage of amniotic fluid, which was replaced before uterine closure) or open microneurosurgery, which is a novel technique characterized by a 15- to 20-mm hysterotomy diameter, reduced fetal manipulation by fixing the fetal back, and maintenance of normal amniotic fluid and uterine volume during the whole surgery. Perinatal outcomes of cases operated with the classic open fetal surgery technique and open microneurosurgery were compared. RESULTS: Intrauterine SB repair with a complete 3-layer correction was successfully performed in 60 cases either by classic open fetal surgery (n = 13) or open microneurosurgery (n = 47). No significant differences were observed in gestational age (GA) at fetal intervention (25.4 vs. 25.1 weeks, p = 0.38) or surgical times (107 vs. 120 min, p = 0.15) between both groups. The group with open microneurosurgery showed a significantly lower rate of oligohydramnios (0 vs. 15.4%, p = 0.01), preterm rupture of the membranes (19.0 vs. 53.8%, p = 0.01), higher GA at birth (35.1 vs. 32.7 weeks, p = 0.03), lower rate of preterm delivery <34 weeks (21.4 vs. 61.5%, p = 0.01), and lower rate of perinatal death (4.8 vs. 23.1%, p = 0.04) than the group with classic open surgery. During infant follow-up, the rate of hydrocephalus requiring ventriculoperitoneal shunting was similar between both groups (7.5 vs. 20%, p = 0.24). All patients showed an intact hysterotomy site at delivery. CONCLUSION: Intrauterine spina repair by open fetal microneurosurgery is feasible and was associated with better perinatal outcomes than classic open fetal surgery.

Prenatal diagnosis of laryngo-tracheo-esophageal anomalies in fetuses with congenital diaphragmatic hernia by ultrasound evaluation of the vocal cords and fetal laryngoesophagoscopy.

BACKGROUND: To evaluate the incidence of laryngeal ultrasound (US) abnormalities in fetuses with congenital diaphragmatic hernia (CDH) and to assess the utility of fetal laryngoesophagoscopy for prenatal diagnosis of laryngo-tracheo-esophageal anomalies. STUDY DESIGN: A cohort of CDH fetuses with laryngeal ultrasound abnormalities were selected for diagnostic fetal laringoesophagoscopy in a single fetal surgery center at Queretaro, Mexico. RESULTS: During the study period, 210 CDH fetuses were evaluated. US examination of the vocal cords was successfully performed in all fetuses, and abnormal ultrasound findings were observed in four cases (1.9%). Fetal laringoesophagoscopy was successfully performed in all four cases at a median gestational age of 29.5 (range, 28.1-30.6) weeks. During fetal intervention, a laryngo-tracheo-esophageal cleft (TEC) extending from the larynx to the carina (type IV) was endoscopically visualized in three cases, and laryngeal atresia coexisting with TEC was confirmed in the remaining case. Fetal karyotype was normal in all cases, but abnormal chromosomal microarray analysis was reported in two cases (50%). All cases were delivered liveborn with severe respiratory failure presenting cardiac arrest and immediate neonatal death. CONCLUSIONS: Laryngeal anomalies in CDH fetuses can be presumed by ultrasound evaluation of the vocal cords and confirmed by fetal laryngoesophagoscopy during pregnancy.

A multicentre study to predict neonatal survival according to lung-to-head ratio and liver herniation in fetuses with left congenital diaphragmatic hernia (CDH): Hidden mortality from the Latin American CDH Study Group Registry.

OBJECTIVE: To evaluate natural history of fetuses congenital diaphragmatic hernia (CDH) prenatally diagnosed in countries where termination of pregnancy is not legally allowed and to predict neonatal survival according to lung area and liver herniation. METHODS: Prospective study including antenatally diagnosed CDH cases managed expectantly during pregnancy in six tertiary Latin American centres. The contribution of the observed/expected lung-to-head ratio (O/E-LHR) and liver herniation in predicting neonatal survival was assessed. RESULTS: From the total population of 380 CDH cases, 144 isolated fetuses were selected showing an overall survival rate of 31.9% (46/144). Survivors showed significantly higher O/E-LHR (56.5% vs 34.9%; P < .001), lower proportion of liver herniation (34.8% vs 80.6%, P < .001), and higher gestational age at birth (37.8 vs 36.2 weeks, P < 0.01) than nonsurvivors. Fetuses with an O/E-LHR less than 35% showed a 3.4% of survival; those with an O/E-LHR between 35% and 45% showed 28% of survival with liver up and 50% with liver down; those with an O/E-LHR greater than 45% showed 50% of survival rate with liver up and 76.9% with liver down. CONCLUSIONS: Neonatal mortality in CDH is higher in Latin American countries. The category of lung hypoplasia should be classified according to the survival rates in our Latin American CDH registry.

Longitudinal changes in lung size and intrapulmonary-artery Doppler during the second half of pregnancy in fetuses with congenital diaphragmatic hernia.

OBJECTIVES: The objectives of the study are to evaluate longitudinal changes in lung size and intrapulmonary-artery (IPa) Doppler in fetuses with congenital diaphragmatic hernia (CDH) and assess their contribution in predicting neonatal survival. METHODS: The observed/expected lung-to-head ratio (O/E-LHR) and IPa-pulsatility index (PI) and peak early diastolic reversed flow (PEDRF) were evaluated in a cohort of left-sided CDH fetuses managed expectantly during pregnancy. Longitudinal changes were analyzed by multilevel analysis, and their value to predict survival using the multiple logistic regression and decision-tree analysis was assessed. RESULTS: A total of 232 scans were performed on 69 CDH fetuses. The O/E-LHR values remained unchanged during fetal monitoring, whereas IPa-PI and PEDRF showed a progressive increase throughout follow-up, becoming abnormal on average at 30 weeks of gestation. Absent/reversed end-diastolic velocity (EDV) in the IPa was observed in 20.3%. O/E-LHR and IPa Doppler indices were significantly associated with probability of survival (O/E-LHR ≥ 26%, odds ratio [OR] 19.0; IPa-PI <+2.0 z score, OR 3.0; and positive EDV, OR 7.4). All cases with IPa-reversed EDV died after birth. CONCLUSION: While lung size remains stable during pregnancy, CDH fetuses show progressive deterioration in intrapulmonary blood flow. IPa Doppler evaluation may aid in predicting survival of CDH fetuses managed expectantly during pregnancy.

Thoracic Changes after Full Laser Ablation of the Feeding Artery in Fetuses with Bronchopulmonary Sequestration.

OBJECTIVE: To assess longitudinal intrathoracic changes after fetal laser surgery in fetuses with bronchopulmonary sequestration (BPS) with hydrops and/or hydrothorax. STUDY DESIGN: The presence of intrafetal fluid effusions, the lung mass volume ratio (congenital pulmonary airway malformation volume ratio [CVR]), and the observed/expected lung-to-head circumference ratio (O/E-LHR) of both lungs were evaluated in a cohort of BPS fetuses with hydrops and/or hydrothorax treated with full laser ablation of the feeding artery (FLAFA). The longitudinal changes in intrafetal fluid effusions, lung mass volume, and pulmonary growth were analyzed by survival and multilevel analysis against days after FLAFA. RESULTS: FLAFA was successfully performed in 15 cases at a median gestational age of 26.9 weeks. A complete disappearance of the hydrops and hydrothorax was observed a median interval of 7.5 and 21 days after the fetal intervention, respectively. A progressive decrease in the CVR and an increment in the size of both lungs were observed after FLAFA. The O/E-LHR of the lung contralateral and ipsilateral to the side of the BPS became normal on average 8 and 10 weeks after FLAFA, respectively. CONCLUSION: Fetal laser surgery with FLAFA promotes disappearance of all fetal fluid effusions, a lung mass regression sequence, and a normalization of pulmonary growth.