In Utero Treatment for Bladder Outlet Obstruction Using Robot Assisted Laparoscopic Techniques

Factors associated with fetal shunt dislodgement in lower urinary tract obstruction

OBJECTIVE

To identify factors associated with fetal shunt dislodgement in lower urinary tract obstruction (LUTO).

METHODS

We conducted a retrospective study of 42 consecutive fetuses with a diagnosis of LUTO in a tertiary fetal center between April 2013 and November 2015. Possible factors associated with prenatal shunt dislodgment were evaluated in fetuses who underwent shunt placement, including gestational age at diagnosis, gestational age at procedure, presence of 'keyhole sign', initial fetal bladder volume and wall thickness, prenatal ultrasonographic renal characteristics, amniotic fluid volume, presence of ascites prior to shunting, and type of fetal shunt.

RESULTS

Nineteen (46.3%) fetuses underwent shunt placement at a median gestational age of 19 (range: 16.3-31.1) weeks. Shunt dislodgement occurred in 10 (52.6%) patients. A total of 35 procedures were performed; among which 16 (45.7%) were repeat procedures. The only prenatal factor associated with shunt dislodgement was the type of the shunt; Kaplan-Meier analysis indicated that the Rocket was associated with increased likelihood of remaining orthotopic (p = 0.04).

CONCLUSION

Fetal shunt dislodgement occurs in approximately half of the patients and appears to be associated with the type of the shunt. Future research is necessary to develop better shunt systems and to investigate different fetal therapeutic approaches. © 2016 John Wiley & Sons, Ltd.

Current applications of in utero intervention for lower urinary tract obstruction

PURPOSE

Since the early 1980s with the inception of fetal intervention for obstructive uropathy, there have been creative attempts to improve both perinatal and long-term outcomes. Despite advances in technology and an improved understanding of lower urinary tract obstruction (LUTO) in the fetus, the results for these therapeutic interventions remain guarded and the long-term renal morbidity among survivors remains problematic.

RECENT FINDINGS

Fetal LUTO represents a range of disorders but the most common of these is posterior urethral valves (PUVs). Selection criteria for candidates of possible intervention have improved with our understanding of fetal renal physiology. Serial urinalysis has marginally improved our ability to predict those that may ultimately respond to treatment [1,2], but the potential in the development of biomarkers for renal development or maldevelopment holds greater promise [3]. Advancements in fetal surgery may result in less fetal and maternal morbidity, but limited long-term improvement in outcomes highlights the controversial nature of the various interventions [4-10]. We must counsel families that fetal surgery offers hope but we cannot allow them to hold unrealistic expectations for cure.

SUMMARY

In appropriately selected fetuses, intervention may improve perinatal survival but not without risk to mother and fetus. Long-term renal outcomes remain problematic amongst survivors. In the case of PUV, postnatal primary valve ablation remains the cornerstone of treatment for nephron preservation; however, our ability to mimic these results in the prenatal population remains poor [11]. Disease severity has likely predetermined those that will survive through the perinatal period with or without intervention. Nonetheless, our drive to assess and manage fetal obstructive uropathy perseveres so that we may ultimately relieve obstruction and preserve renal and lung function. We must maintain optimism that continued advances will ultimately improve outcomes, but also be realistic with our current expectations. This paper reviews the status of current in utero interventions and outcomes.