Early vesico-amniotic shunting - does it change the prognosis in fetal lower urinary tract obstruction diagnosed in the first trimester?

Vesicoamniotic Shunting before 17 + 0 Weeks in Fetuses with Lower Urinary Tract Obstruction (LUTO): Comparison of Somatex vs. Harrison Shunt Systems

(1) Background: The aim of this study was to compare perinatal outcomes and complication rates of vesicoamniotic shunting (VAS) before 17 + 0 weeks in isolated LUTO (lower urinary tract obstruction) with the Somatex® intrauterine shunt vs. the Harrison fetal bladder shunt. (2) Methods: This is a retrospective cohort study in two tertiary fetal medicine centers. From 2004−2014, the Harrison fetal bladder shunt was used, and from late 2014−2017, the Somatex shunt. Obstetrics and pediatric charts were reviewed for complications, course of pregnancy, perinatal outcome, and postnatal renal function. (3) Results: Twenty-four fetuses underwent VAS with a Harrison (H) shunt and 33 fetuses with a Somatex (S) shunt. Live birth rates and survival to last follow-up were significantly higher in the Somatex group, at 84.8% and 81.8%, respectively, vs. 50% and 33.3% in the Harrison group (p = 0.007 and p < 0.001). The dislocation rate in the Somatex group (36.4%) was significantly lower than in the Harrison group (87.5%) (p < 0.001). The median time to dislocation was significantly different, at 20.6 days (H) vs. 73.9 days (S) (p = 0.002), as was gestational age at dislocation (17 (H) vs. 25 (S) weeks, p < 0.001). Renal function was normal in early childhood in 51% (S) vs. 29% (H) (p = 0.11). (4) Conclusions: VAS before 17 + 0 weeks gestational age with a Somatex shunt improves perinatal survival significantly and might even have a positive effect on renal function, probably due to the lower dislocation rates. A normal amount of amniotic fluid in the third trimester was the best predictor of normal renal function in early childhood.

Vesico-amniotic shunt insertion prior to the completion of 16 weeks results in improved preservation of renal function in surviving fetuses with isolated severe lower urinary tract obstruction (LUTO)

PURPOSE

The purpose of this retrospective cohort study was to compare the outcome of human fetuses with isolated severe lower urinary tract obstructions (LUTO) that were first treated before the completion of 16 weeks of gestation to fetuses first treated later in gestation.

PATIENTS AND METHODS

Vesicoamniotic shunt insertion (VAS) was performed in 63 subsequent fetuses with LUTO between 12 + 5 and 30 + 3 weeks. The fetuses were analyzed in three groups: Group-I-fetuses underwent their first intervention until the completion of 16 weeks, Group-II-fetuses were first treated between 16 + 1 and 24 + 0 weeks and Group-III-fetuses beyond 24 + 1 weeks. Renal and pulmonary outcome parameters and complicating factors were assessed.

RESULTS

- All mothers tolerated the procedures well. Overall fetal survival was 47 of 63 (75%). The mean age at delivery of survivors was 35 weeks. 68% of Group-I-fetuses, 77% of group-II-fetuses, and 100% of group-III-fetuses survived beyond postnatal hospital discharge. Amongst the survivors the chance for normal renal function was higher for group I with 79% (15/19) compared to first fetal intervention after the completion of 16 weeks with 32% (9/28, p = 0.003, OR = 7.9 [2.0, 30.8] 95% CI). Clinically relevant pulmonary hypoplasia was observed in 11% of Group-I-, 27% of Group-II-, and 20% of Group-III-fetuses.

CONCLUSIONS

Early intervention in fetal LUTO before the completion of 16 weeks may achieve a higher rate of normal renal and pulmonary function in survivors than treatment beyond that point in time. This observation is important for the future management of this challenging patient population.

Postnatal Management in Congenital Lower Urinary Tract Obstruction With and Without Prenatal Vesicoamniotic Shunt

Purpose: Congenital lower urinary tract obstruction (cLUTO) includes a heterogeneous group of conditions caused by a functional or mechanical outlet obstruction. Early vesicoamniotic shunting (VAS) possibly reduces the burden of renal impairment. Postpartum, pediatric urologists are confronted with neonates who have a shunt in place and a potentially impassable urethra with a narrow caliber. Early management of these patients can be challenging. Here, we would like to share the approach we have developed over time. Materials and Methods: We conducted a single-center retrospective analysis from 2016 to 2020 and included all patients diagnosed with cLUTO. Data focusing on time point and type of intervention was collected. Furthermore, patients with temporary diversion via a percutaneous VAS were selected for a more detailed review. Results: In total, 71 cases of cLUTO were identified during the study period. Within this group, 31 neonates received postnatal management and surgical intervention in our center. VAS was performed in 55% of these cases (N = 17). The postnatal treatment varied between transurethral or suprapubic catheterization and early Blocksom vesicostomy. In five infants with VAS, the urinary drainage was secured through the existing VAS by inserting a gastric tube (N = 1) or a 4.8 Fr JJ-stent (N = 4). To our knowledge, this is the first report of a stent-in-stent scheme, which can remain indwelling until the definite treatment. Conclusion: Having a secure urine drainage through a VAS allows the often premature infant to grow until definite surgery can be performed. This avoids placing a vesicostomy, which requires anesthesia.

Urethroplasty with balloon catheterization in fetal lower urinary tract obstruction: observational study of 10 fetuses

OBJECTIVE

To present the preliminary outcomes of fetal urethroplasty using a coronary angioplasty balloon catheter in lower urinary tract obstruction (LUTO).

METHODS

We included 10 consecutive male fetuses diagnosed with LUTO caused by presumed isolated posterior urethral valves (PUVs), who underwent urethroplasty with a balloon catheter in our center between 2015 and 2018. During urethroplasty, the fetal urethra was dilated using a balloon catheter (diameter, 0.014 inches; balloon size, 2 × 9 mm) inserted under ultrasonographic guidance via an 18-gauge needle introduced into the fetal bladder.

RESULTS

Mean gestational age at the time of urethroplasty was 17.8 (range, 16.5-20.4) weeks. All fetuses survived the procedure without any complications and there was no case of preterm prelabor rupture of the membranes. The procedure was successful in 5/10 (50%) fetuses, while in the other five (50%), we were unable to insert the balloon catheter into the urethra. In the five successfully treated cases, mean gestational age at delivery was 38 (range, 36-40) weeks and presence of PUVs was confirmed after birth. All five neonates micturated spontaneously and presented with normal urine output after birth. During the follow-up period, the parameters of kidney function were within normal limits in two neonates, whereas signs of impaired renal function were seen in another two. The other was diagnosed with renal insufficiency and required kidney transplant with bladder sparing at 2 years of age.

CONCLUSIONS

Urethroplasty with a balloon catheter is a new prenatal treatment option for fetuses with PUVs. By restoring fetal micturition, the procedure can preserve normal urinary bladder and kidney function. Although data on its efficacy and potential to differentiate the etiology of LUTO are sparse, a significant advantage of this method is its safety for the fetus and the mother. Even if the neonates develop renal insufficiency, they may be eligible for kidney transplant with connection to their own bladder, without the need for urostomy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Vesicoamniotic shunting for fetal megacystis in the first trimester with a Somatex® intrauterine shunt

Purpose

The objective was to evaluate the feasibility of vesicoamniotic shunting (VAS) in the first trimester with the Somatex^® intrauterine shunt and report on complications and neonatal outcome.

Methods

Retrospective cohort study of all VAS before 14 weeks at two tertiary fetal medicine centres from 2015 to 2018 using a Somatex^® intrauterine shunt. All patients with a first trimester diagnosis of megacystis in male fetuses with a longitudinal bladder diameter of at least 15 mm were offered VAS. All patients that opted for VAS after counselling by prenatal medicine specialists, neonatologists and pediatric nephrologists were included in the study. Charts were reviewed for complications, obstetric and neonatal outcomes.

Results

Ten VAS were performed during the study period in male fetuses at a median GA of 13.3 (12.6–13.9) weeks. There were two terminations of pregnancy (TOP) due to additional malformations and one IUFD. Overall there were four shunt dislocations (40%); three of those between 25–30 weeks GA.

Seven neonates were born alive at a median GA of 35.1 weeks (31.0–38.9). There was one neonatal death due to pulmonary hypoplasia. Neonatal kidney function was normal in the six neonates surviving the neonatal period. After exclusion of TOP, perinatal survival was 75%, and 85.7% if only live-born children were considered.

Conclusion

VAS in the first trimester is feasible with the Somatex^® Intrauterine shunt with low fetal and maternal complication rates. Neonatal survival rates are high due to a reduction in pulmonary hypoplasia and the rate of renal failure at birth is very low. VAS can be safely offered from the late first trimester using the Somatex^® intrauterine shunt.

Antenatal Workup of Early Megacystis and Selection of Candidates for Fetal Therapy

OBJECTIVE

To investigate the best criteria for discriminating fetuses with isolated posterior urethral valves from those theoretically not eligible for fetal treatment because of complex megacystis, high chance of spontaneous resolution, and urethral atresia.

METHODS

A retrospective national study was conducted in fetuses with megacystis detected before 17 weeks' gestation (early megacystis).

RESULTS

In total, 142 cases with fetal megacystis were included in the study: 52 with lower urinary tract obstruction, 29 with normal micturition at birth, and 61 with miscellaneous syndromal associations, chromosomal and multiple structural abnormalities (complex megacystis). Only a nuchal translucency > 95th centile, and not a longitudinal bladder diameter ≤15 mm (p = 0.24), significantly increased the risk of complex megacystis (p < 0.01). Cases with a high chance of spontaneous resolution were identified by using the cut-off of 12 mm, as demonstrated in a previous study, and the finding of an associated umbilical cord cyst carried a high-risk of urethral atresia (odds ratio: 15; p = 0.026), an unfavorable condition for antenatal treatment. An algorithm encompassing these three criteria demonstrated good accuracy in selecting fetuses theoretically eligible for fetal treatment (specificity 73%; sensitivity 92%).

CONCLUSIONS

Cases theoretically eligible for early fetal therapy are those with normal nuchal translucency, a longitudinal bladder diameter > 12 mm, and without ultrasound evidence of umbilical cord cysts.