Survival and neonatal outcome after fetoscopic guided laser occlusion (FLOC) of twin-to-twin transfusion syndrome (TTTS) in Sweden

Laser fetoscopy ablation for twin-twin transfusion syndrome may reduce the risk of ROP

PURPOSE

Twin-twin transfusion syndrome (TTTS) is a condition wherein monochorionic twins share a common placenta with placental anastomoses between the two foetal circulations. Most infants who survive TTTS are born prematurely. This study aimed to determine whether fetoscopic laser ablation (FLA) can reduce the risk of retinopathy of prematurity (ROP) and whether TTTS was a risk factor for ROP.

METHODS

This single-centre, retrospective, comparative study included 32 monochorionic twins with TTTS matched for gestational age, birthweight and sex to premature twins and singletons without TTTS (n = 68; twins, n = 34; and singletons, n = 34) born between 2003 and 2022. A single ophthalmologist recorded the fundus findings. FLA was performed using Solomon's technique to separate the vascular systems of the twins with TTTS.

RESULTS

The gestational age and weight of premature infants with TTTS treated with FLA were significantly higher than those of untreated infants (p = 0.001 and p = 0.001, respectively); however, the hyaline membrane grade was lower (p = 0.004). A significant increase in weight (g/day) (p = 0.002) and lesser avascular area in the peripheral temporal retina (p = 0.045) was observed at postnatal week 4. The risk of ROP in the FLA group was 2.6 times (13.3% vs. 35.3%) lower than that in the non-FLA group; however, this difference was not significant. The incidence of any stage of ROP (25% vs. 18%) and treatment for ROP type 1 (6.25% vs. 5.9%) did not differ significantly between monochorionic twins with TTTS and premature infants without TTTS.

CONCLUSION

The gestational age of premature infants with TTTS treated with FLA was higher than that of untreated infants. Moreover, a reduction in complications of prematurity was also observed. Laser fetoscopy in twin-twin transfusion syndrome may reduce the risk of ROP, but the difference was not statistically significant in this small study.

Increased Risk of Retinopathy of Prematurity in Donors with Twin-to-Twin Transfusion Syndrome: A Cohort Study

INTRODUCTION

The purpose of this study was to evaluate the within-pair difference in retinopathy of prematurity (ROP) between donors and recipients with twin-to-twin transfusion syndrome (TTTS) and to identify risk factors for ROP development.

METHODS

This retrospective cohort study included 147 TTTS twin pairs managed between 2002 and 2022 and eligible for ROP screening. Primary outcomes were any stage ROP and severe ROP. Secondary outcomes were hemoglobin at birth, red blood cell transfusions, mechanical ventilation days, postnatal steroids, and neonatal morbidity. Donor status was defined as having polyhydramnios pre-laser.

RESULTS

Rates of any stage ROP (23% vs. 14%) and severe ROP (8% vs. 3%) were significantly higher in donors compared to recipients. Donors received a higher number of blood transfusions (1 [±1.9] versus 0.7 [±1.5]). Five factors were univariately associated with any stage ROP: donor status (odds ratio [OR] 1.9; 95% CI 1.3-2.9), lower gestational age (GA) at birth (OR 1.7; 95% CI 1.4-2.1), small for GA (OR 2.1; 95% CI 1.3-3.5), mechanical ventilation days (OR 1.1; 95% CI 1.1-1.2), and blood transfusions in phase 1 (OR 2.3; 95% CI 1.2-4.3). Three factors were independently associated with any stage ROP: donor status (OR 1.8; 95% CI 1.1-2.9), lower GA at birth (OR 1.6; 95% CI 1.2-2.1), and mechanical ventilation days (OR 1.1, 95% CI 1.0-1.1). Donor status was univariately associated with severe ROP (OR 2.3, 95% CI 1.1-5.0).

CONCLUSION

Any stage ROP and severe ROP are detected twice as frequently in donors compared to recipients. Increased awareness for ROP is needed in donors, especially those with lower GA at birth and longer duration of mechanical ventilation.

Twin-twin transfusion syndrome in the era of fetoscopic laser surgery: antenatal management, neonatal outcome and beyond

Introduction: Twin-twin transfusion syndrome (TTTS) is a devastating complication of monochorionic twin pregnancy and remains a major challenge for worldwide fetal medicine specialists. In TTTS, intertwin transfusion through vascular anastomoses in the shared placenta leads to severe hemodynamic imbalance. This review summarizes the current knowledge of TTTS.Areas covered: The most recent insights concerning the management of TTTS, as well as fetal and neonatal complications are described. Relevant articles were selected based on a Pubmed search using the keywords below. Understanding of the underlying pathophysiology has improved greatly as a result of placental injection studies. Advancements in antenatal management have led to increased perinatal survival and a decreased incidence of neonatal complications, including brain injury and neurodevelopmental impairment.Expert opinion: Further opportunities for improvement comprise technological innovations in laser procedures and the prevention of preterm rupture of membranes with subsequent prematurity. A noninvasive treatment such as high-intensity focused ultrasound (HIFU) seems to hold promise for the future treatment of TTTS. Fetal MRI studies are important to improve our understanding of fetal brain injury and should relate their findings to long-term neurodevelopment. International collaboration and centralization of care are of paramount importance to ensure the best care for our patients.

Chronic kidney disease following twin-to-twin transfusion syndrome-long-term outcomes

BACKGROUND

Amongst other sequelae, acute kidney injury (AKI) is a well-recognised post-natal complication of twin-to-twin transfusion syndrome (TTTS). Despite this, there has been a lack of data reporting long-term renal outcomes. Our aim was to report the long-term renal outcomes of infants born with TTTS.

METHODS

We performed a retrospective case note review of all infants referred to our centre between 1998 and 2018 with a primary diagnosis of TTTS. Subjects with confirmed TTTS were divided into a chronic kidney disease (CKD) group and a non-CKD group for comparison.

RESULTS

Twenty-six infants with TTTS were included for analysis. Eight (31%) subjects developed CKD. Within the CKD group, 50% went on to require long-term renal replacement therapy (RRT) of whom all underwent renal transplantation. For subjects who had neonatal AKI, cumulative survival rate before RRT at 5 and 10 years was 79% and 70%, respectively. Subjects with CKD had a significantly higher incidence of AKI in the neonatal period and were more likely to be the donor twin. Gestational age at birth, gender, antenatal interventions and comorbidities did not affect long-term renal outcome between the two groups.

CONCLUSION

This is the first long-term follow-up study demonstrating that CKD progressing to the need for RRT can develop after TTTS. Donor-twin status and neonatal AKI associated with adverse long-term outcomes warranting long-term surveillance in this group.

Fetal Survival Immediate after Fetoscopic Laser Ablation in Twin to Twin Transfusion Syndrome

BACKGROUND

The purpose of this study was to determine prognostic factors that can affect the fetal survival immediate after fetoscopic laser ablation.

METHODS

The study population consisted of consecutive twin pregnant women who underwent fetoscopic laser ablation with the diagnosis of twin to twin transfusion syndrome (TTTS) from 2011 to 2018 in Seoul National University Hospital. Fetal survival immediate after procedure was defined as survival to 48 hours after procedure and neonatal survival was defined as survival to 28 days of life. Clinical characteristics and ultrasound findings were compared according to the fetal survival immediate after procedure.

RESULTS

A total of 57 pregnant women with TTTS were included, and the overall fetal survival immediate after procedure was 71.1% (81/114) after fetoscopic laser ablation. Fetuses who survived immediate after procedure had higher gestational age at procedure and lower frequency of abnormal Doppler studies than those did not survive. However, the frequency of hydrops was not different between cases with fetal survival and those with fetal death. The earlier gestational age at procedure and the presence of abnormal Doppler studies were significant risk factors for fetal death even after adjustment.

CONCLUSION

Based on this data, the fetal survival immediate after procedure (fetoscopic laser treatment) in TTTS can be affected by the gestational age at procedure and the presence of abnormal Doppler studies.

Renal function in neonates with twin-twin transfusion syndrome treated with or without fetoscopic laser surgery

The aim of this study is to investigate the short-term renal function in neonates with twin-twin transfusion syndrome (TTTS), treated with fetoscopic laser surgery (laser group) or conservatively (non-laser group). Creatinine and urea levels and urine output were recorded in the first week after birth. Primary outcome was short-term renal dysfunction, defined as a creatinine level of >100 μmol/L during the first week postpartum. We evaluated 312 twins (laser group, n = 274; non-laser group, n = 38). Median creatinine and urea levels were lower in the laser group than in the non-laser group (71 versus 82 μmol/L, p = 0.002). Short-term renal dysfunction was lower in the laser group compared to the non-laser group (7.2 versus 34.4%, p < 0.001). Within the laser group, creatinine levels were significantly higher in the subgroup with incomplete laser surgery compared to twins with successful laser surgery (76 versus 69 μmol/L, p = 0.018). No differences were found between donors and recipients except for a higher incidence of oliguria in donors in the non-laser group on day 1.

CONCLUSION

Short-term renal dysfunction occurs less frequently in TTTS twins treated with fetoscopic laser coagulation, particularly after complete surgery, suggesting that laser surgery may have a protective effect on renal function. What is Known: • Antenatally, donor twins in TTTS have severe oliguria due to chronic hypovolemia and impaired renal perfusion • Postnatally, donor twins may suffer from severe renal complications, particularly in TTTS twins treated conservatively. What is New: • The incidence of short-term renal failure in TTTS twins treated with complete laser surgery is low. • After incomplete laser surgery, the incidence of short-term renal dysfunction is increased.

Childhood cardiac outcome after intrauterine laser treatment of twin-twin transfusion syndrome is favourable

AIM

Intrauterine laser treatment is used to alleviate abnormal circulatory load and cardiac morbidity affecting foetuses with twin-twin transfusion syndrome (TTTS). We conducted this childhood follow-up study to fill the gap in knowledge about final cardiac outcomes after such interventions.

METHODS

We investigated 19 TTTS pairs - 11 male and eight female - with a mean age of four and a half years (range 1.1-9.9) using 2D, blood flow and tissue Doppler, 3D and speckle tracking echocardiography, and compared them with 19 age-matched and gender-matched singletons.

RESULTS

The only observed differences in cardiac structure or function between the donors and recipients were related to diastolic ventricular filling. Recipients had a lower left ventricular ratio of early and late diastolic filling compared with their donor cotwins [1.48(0.35) versus 1.66 (0.28), p < 0.05], but not compared with singleton controls. All observations, except one, were within the reference limits. Speckle tracking could not demonstrate any group differences in systolic ventricular function, besides marginally lower ventricular strain in the donors than controls.

CONCLUSION

Double survivors of laser-treated TTTS showed only minor within-pair differences in diastolic cardiac function at childhood follow-up. Cardiac function in TTTS twins compared well to singleton controls, suggesting a favourable long-term outcome.