Percutaneous fetal cystoscopy and endoscopic fulguration of posterior urethral valves

Prenatal Diagnoses and Intervention

Fetal upper tract urinary system dilation is one of the most common findings on prenatal ultrasonography. Rarely, this may represent fetal lower urinary tract obstruction (LUTO), of which posterior urethral valves are the predominant etiology. LUTO is the most dire fetal urologic diagnosis, as it affects not only the baby's management after birth but sometimes the course of the pregnancy itself. A variety of treatment options are available prenatally; these include observation, vesicoamniotic shunt placement, amnioinfusion, and attempts at direct treatment of the valves themselves. All fetal interventions carry substantial risks; caution should attend every discussion of treatment.

Renal-Protective Urinoma Formation in a Newborn Boy With Posterior Urethral Valves

Posterior urethral valves (PUV) are an uncommon urologic congenital anomaly in males often discovered antenatally and more rarely after birth. PUV can lead to obstructive nephropathy and voiding dysfunction, putting patients at increased risk for irreversible renal damage and subsequent progression to end-stage renal disease. Much of the renal damage caused by PUV is proportional to the amount of time that the kidney has been experiencing retrograde pressure. Although much debate exists within the field, spontaneous decompression within the collecting system (e.g., "pop-off" valve) such as urinoma formation or spontaneous ascites has been found to relieve pressure on and thus protect the kidney, decreasing the risk of progression to advanced stages of chronic kidney disease. Despite the significant mass effect on the renal parenchyma, the pressure-relieving function of urinoma formation is a net protective factor allowing renal function to be preserved. We report a unique case of antenatal detection of PUV in a male with postnatal complicated urinoma formation secondary to forniceal rupture. Remarkably, despite significant external compression of the kidney and the development of urosepsis from infection of the urinoma with a multidrug-resistant organism that required percutaneous drainage, renal function was preserved throughout the disease course. After ablation of the PUV and drainage of the septic urinoma, the patient recovered rapidly after intervention and was ultimately discharged in stable condition.

Fetal Therapy for Renal Anhydramnios

The most severe forms of congenital anomalies of the kidney and urinary tract present in fetal life with early pregnancy renal anhydramnios and are considered lethal due to pulmonary hypoplasia without fetal therapy. Due to the high rate of additional structural anomalies, genetic abnormalities, and associated syndromes, detailed anatomic survey and genetic testing are imperative when stratifying which pregnancies are appropriate for fetal intervention. Restoring amniotic fluid around the fetus is the principal goal of prenatal treatment. The ongoing multi-center Renal Anhydramnios Fetal Therapy (RAFT) trial is assessing the safety and efficacy of serial amnioinfusions to prevent pulmonary hypoplasia so that the underlying renal disease can be addressed.

Modern fetal surgery-a historical review of the happenings that shaped modern fetal surgery and its practices

The history of fetal surgery is one of constant evolution. Over the last 50 years, fetal surgery has progressed from a mere idea to an internationally respected innovative field of surgery. This article aims to provide a historical review of how the enterprise of maternal-fetal surgery came to be its modern version. This review is less focused on the history of specific therapies for a relatively small number of conditions, and more on how the whole field of maternal-fetal surgery evolved. The various internal and external influences that steered the field's evolution are discussed in chronologic order. Since the start of modern fetal surgery in the 1980s, large paradigm shifts have characterized the growth of the field as a whole. Innovative interventions are now based on physiologic manipulation as opposed to simple anatomic repair, fetoscopy has become the more frequently preferred surgical approach, and rigorous scientific evaluation with randomized controlled trials is now the standard expected by the community. In a very similar fashion to when the field first began in the early 1980s, recently community's leaders have risen to protect the integrity of maternal-fetal surgery by publishing ethical guidelines for innovation and clinical practice. This incredible history of innovation, rigorous science and ethical contemplation is the foundation on which modern maternal-fetal surgery rests.

Current perspective and scope of fetal therapy: part 1

Fetal therapy term has been described for any therapeutic intervention either invasive or noninvasive for the purpose of correcting or treating any fetal malformation or condition. Fetal therapy is a rapidly evolving specialty and has gained pace in last two decades and now fetal intervention is being tried in many malformations with rate of success varying with the type of different fetal conditions. The advances in imaging techniques have allowed fetal medicine persons to make earlier and accurate diagnosis of numerous fetal anomalies. Still many fetal anomalies are managed postnatally because the fetal outcomes have not changed significantly with the use of fetal therapy and this approach avoids unnecessary maternal risk secondary to inutero intervention. The short-term maternal risk associated with fetal surgery includes preterm labor, premature rupture of membranes, uterine wall bleeding, chorioamniotic separation, placental abruption, chorioamnionitis, and anesthesia risk. Whereas, maternal long-term complications include risk of infertility, uterine rupture, and need for cesarean section in future pregnancies. The decision for invasive fetal therapy should be taken after discussion with parents about the various aspects like postnatal fetal outcome without fetal intervention, possible outcome if the fetal intervention is done, available postnatal intervention for the fetal condition, and possible short-term and long-term maternal complications. The center where fetal intervention is done should have facility of multi-disciplinary team to manage both maternal and fetal complications. The major issues in the development of fetal surgery include selection of patient for intervention, crafting effective fetal surgical skills, requirement of regular fetal and uterine monitoring, effective tocolysis, and minimizing fetal and maternal fetal risks. This review will cover the surgical or invasive aspect of fetal therapy with available evidence and will highlight the progress made in the management of fetal malformations in last two decades.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

Consensus on the Management of Posterior Urethral Valves from Antenatal Period to Puberty

The need for successful management of posterior urethral valves always captivates the minds of pediatric surgeons. Its success, however, depends on several factors ranging from prenatal preservation of upper tracts to postoperative pharmacological compliance. Regardless of measures available, some cases do not respond and progress to end stage. The management depends on several issues ranging from age and severity at presentation to long-term follow-up and prevention of secondary renal damage and managing valve bladder syndrome. This article is based on a consensus to the set of questionnaires, prepared by research section of Indian Association of Paediatric Surgeons and discussed by experienced pediatric surgeons based in different institutions in the country. Standard operating procedures for conducting a voiding cystourethrogram and cystoscopy were formulated. Age-wise contrast dosage was calculated for ready reference. Current evidence from literature was also reviewed and included to complete the topic.

Clinical Outcome of Children With Antenatally Diagnosed Hydronephrosis

Fetal renal pelvis dilation is a common condition, which is observed in 1-4. 5% of pregnancies. In many cases, this finding resolves spontaneously. However, sometimes it may be a signal of significant urinary tract pathologies. The main abnormalities found after birth are uretero-pelvic junction stenosis, primary vesicoureteral reflux, megaureter, duplex kidneys, and posterior urethral valves, with uretero-pelvic junction stenosis and primary vesicoureteral reflux accounting for most of the cases. Diagnosis, management, and prognosis at short and longer term of these conditions will be reviewed in this article.

Lessons from the Barn to the Operating Suite: A Comprehensive Review of Animal Models for Fetal Surgery

The International Fetal Medicine and Surgery Society was created in 1982 and proposed guidelines for fetal interventions that required demonstrations of the safety and feasibility of intended interventions in animal models prior to application in humans. Because of their short gestation and low cost, small animal models are useful in early investigation of fetal strategies. However, owing to the anatomic and physiologic differences between small animals and humans, repeated studies in large animal models are usually needed to facilitate translation to humans. Ovine (sheep) models have been used the most extensively to study the pathophysiology of congenital abnormalities and to develop techniques for fetal interventions. However, nonhuman primates have uterine and placental structures that most closely resemble those of humans. Thus, the nonhuman primate is the ideal model to develop surgical and anesthetic techniques that minimize obstetrical complications.

Fetal surgery: a critical review

Therapeutic fetal surgical procedures are predicated upon the ability to make an accurate fetal diagnosis. The earliest open fetal surgical procedures were introduced in the 1960s to treat Rh isoimmunisation. They were introduced when it became possible to predict impending fetal demise. Open procedures were abandoned when percutaneous approaches proved superior. The introduction of fetal ultrasound allowed the diagnosis of other congenital anomalies, some being amenable to fetal interventions. Open fetal surgical procedures were initially utilised, with significant maternal morbidity. For some anomalies, percutaneous approaches became favoured. In general, all of these procedures involved significant risks to the mother, to save a baby that was likely to die before or shortly after birth without fetal intervention. Fetal repair for myelomeningocele was a "sea change" in approach. The same maternal risks were taken to improve the quality of life of the affected fetus, not save its life. The completion of the "MOMs Trial" has occasioned a "tsunami" of centres in North America applying this approach. Others are attempting percutaneous repairs, with mixed results. This paper reviews the history of fetal surgery, focusing on the themes of the tension between accurate diagnosis and prognosis and open versus "minimally invasive" approaches.

Fetal lower urinary tract obstruction: proposal for standardized multidisciplinary prenatal management based on disease severity

OBJECTIVE

To present a single center experience of a standardized prenatal multidisciplinary management protocol for fetal lower urinary tract obstruction (LUTO) and to propose a classification of fetal LUTO based on disease severity.

METHODS

This was a retrospective cohort study of 25 consecutive fetal patients with prenatal diagnosis of primary LUTO. Fetal intervention was offered after evaluation by a multidisciplinary team. Analyses were conducted using Bayesian methodology to determine predictors of survival at 6 months postpartum. Odds ratios (ORs) with 95% credibility intervals are reported.

RESULTS

Fifteen (60.0%) of the 25 patients referred for assessment survived to postnatal evaluation. Fetal vesicoamniotic shunt was placed in 14 (56.0%) patients with 12 survivors. Multivariable analysis suggested that fetal intervention (OR, 6.97 (0.88-70.16), Pr(OR > 1) = 96.7%), anhydramnios (OR, 0.12 (0.04-0.35), Pr(OR < 1) = 99.9%), favorable fetal urine analysis (OR, 3.98 (0.63-25.15), Pr(OR > 1) = 92.7%) and absence of renal cortical cysts (OR, 3.9 (0.66-24.2), Pr(OR > 1) = 93.3%) were predictors of survival.

CONCLUSIONS

Fetal intervention and fetal renal function were independently associated with postnatal survival of fetuses with LUTO. A classification based on the severity of disease is proposed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

In-utero radiofrequency ablation in fetal piglets: Lessons learned

INTRODUCTION

Radiofrequency ablation (RFA) is increasingly utilized in minimally invasive fetal intervention. However, the response of different fetal tissues to RFA is poorly characterized. We sought to determine the extent of RFA damage in a fetal environment.

METHODS

90Day gestation Yorkshire piglets (term 115days) were subjected to RFA of the chest and abdominal viscera under various temperatures and wattages. The extent of tissue damage was determined by NADPH diaphorase histochemistry.

RESULTS

Tyne temperature was widely variable and displayed varying responses between lung and liver tissue. Tyne exposure to amniotic fluid resulted in an increase in amniotic fluid temperature. Collateral damage, even across the diaphragm, was readily seen, and ultrasonography did not always reflect this injury.

CONCLUSIONS

Utilization of extracorporeal tynes heats fluid at a greater rate than solid tissue and reliance on temperature sensitive probes may result in overheating. The extent of injury may extend beyond damage observed by ultrasound examination and varies for different tissues. Additional studies on the use of devices that regulate tyne temperature are needed to define optimal conditions and better define the extent of adjacent tissue injury.

Defining and predicting 'intrauterine fetal renal failure' in congenital lower urinary tract obstruction

BACKGROUND

The aim of this study was to identify predictors of 'intrauterine fetal renal failure' in fetuses with severe congenital lower urinary tract obstruction (LUTO).

METHODS

We undertook a retrospective study of 31 consecutive fetuses with a diagnosis of LUTO in a tertiary Fetal Center between April 2013 and April 2015. Predictors of 'intrauterine fetal renal failure' were evaluated in those infants with severe LUTO who had either a primary composite outcome measure of neonatal death in the first 24 h of life due to severe pulmonary hypoplasia or a need for renal replacement therapy within 7 days of life. The following variables were analyzed: fetal bladder re-expansion 48 h after vesicocentesis, fetal renal ultrasound characteristics, fetal urinary indices, and amniotic fluid volume.

RESULTS

Of the 31 fetuses included in the study, eight met the criteria for 'intrauterine fetal renal failure'. All of the latter had composite poor postnatal outcomes based on death within 24 h of life (n = 6) or need for dialysis within 1 week of life (n = 2). The percentage of fetal bladder refilling after vesicocentesis at time of initial evaluation was the only predictor of 'intrauterine fetal renal failure' (cut-off <27 %, area under the time-concentration curve 0.86, 95 % confidence interval 0.68-0.99; p = 0.009).

CONCLUSION

We propose the concept of 'intrauterine fetal renal failure' in fetuses with the most severe forms of LUTO. Fetal bladder refilling can be used to reliably predict 'intrauterine fetal renal failure', which is associated with severe pulmonary hypoplasia or the need for dialysis within a few days of life.

Fetal intervention for severe lower urinary tract obstruction: a multicenter case-control study comparing fetal cystoscopy with vesicoamniotic shunting

OBJECTIVE

To evaluate the efficacy of fetal intervention using fetal cystoscopy or vesicoamniotic shunting in the treatment of severe lower urinary obstruction (LUTO).

METHODS

A cohort of 111 fetuses with severe LUTO attending two centers between January 1990 and August 2013 were included retrospectively. Fetuses were categorized into three groups based on the method of intervention: (1) fetal cystoscopy, (2) vesicoamniotic shunting or (3) no intervention. Multivariate analyses were performed to determine the probability of survival and normal renal function until 6 months of age by comparing fetal cystoscopy and vesicoamniotic shunting to no fetal intervention.

RESULTS

Of the 111 fetuses with severe LUTO that were included in the analysis, fetal cystoscopy was performed in 34, vesicoamniotic shunting was performed in 16 and there was no fetal intervention in 61. Gestational age at diagnosis, method of fetal intervention and cause of bladder obstruction were associated with prognosis. In multivariate analysis and after adjustment for potential confounders (considering all causes of LUTO) the overall probability of survival was significantly higher with fetal cystoscopy and vesicoamniotic shunting when compared to no intervention (adjusted relative risk (ARR), 1.86 (95% CI, 1.01-3.42; P = 0.048) and ARR, 1.73 (95% CI, 1.01-3.08; P = 0.04) respectively). A clear trend for normal renal function was present in the fetal cystoscopy group (ARR, 1.73 (95% CI, 0.97-3.08; P = 0.06)) but was not observed in the vesicoamniotic shunt group (ARR, 1.16 (95% CI, 0.86-1.55; P = 0.33)). In cases in which there was a postnatal diagnosis of posterior urethral valves, fetal cystoscopy was effective in improving both the 6-month survival rate and renal function (ARR, 4.10 (95% CI, 1.75-9.62; P < 0.01) and 2.66 (95% CI, 1.25-5.70; P = 0.01) respectively) while vesicoamniotic shunting was associated only with an improvement in the 6-month survival rate (ARR, 3.76 (95% CI, 1.42-9.97; P < 0.01)) with no effect on renal function (ARR, 1.03 (95% CI, 0.49-2.17, P = 0.93)).

CONCLUSION

Fetal cystoscopy and vesicoamniotic shunting improve the 6-month survival rate in cases of severe LUTO. However, only fetal cystoscopy may prevent impairment of renal function in fetuses with posterior urethral valves. Our data support the idea of performing a subsequent randomized controlled trial to compare the effectiveness of fetal cystoscopy vs vesicoamniotic shunting for severe fetal LUTO.

Laser Ablation of Posterior Urethral Valves by Fetal Cystoscopy

Objective: To report the results of fetal cystoscopic laser ablation of posterior urethral valves (PUV) in a consecutive series in two referral centers. Methods: Twenty pregnant women with a presumptive isolated PUV were treated with fetal cystoscopy under local anesthesia. Identification and fulguration of the PUV by one or several firing-contacts with diode laser were attempted. Perinatal and long-term outcomes were prospectively recorded. Results: The median gestational age at procedure was 18.1 weeks (range 15.0-25.6), and median operation time was 24 min (range 15-40). Access to the urethra was achieved in 19/20 (95%) cases, and postoperative, normalization of bladder size and amniotic fluid was observed in 16/20 (80%). Overall, there were 9 (45%) terminations of pregnancy and 11 women (55%) delivered a liveborn baby at a mean gestational age of 37.3 (29.1-40.2) weeks. No infants developed pulmonary hypoplasia and all were alive at 15-110 months. Eight (40% of all fetuses, 72.7% of newborns) had normal renal function and 3 (27.3%) had renal failure awaiting renal transplantation. Conclusion: Fetoscopic laser ablation for PUV can achieve bladder decompression and amniotic fluid normalization with a single procedure in selected cases with anyhydramnios. There is still a significant risk of progression to renal failure pre or postnatally.

Lower urinary tract obstruction in the fetus and neonate

This article summarizes the most recent literature regarding congenital lower urinary tract obstruction in the fetus and newborn. Lower urinary tract obstruction is a heterogeneous group of rare diagnoses that have significant potential for in utero mortality and long-term morbidity in survivors. The diagnosis and management of the most common causes are reviewed. In addition, the current state of prenatal intervention for congenital lower urinary tract obstruction is discussed.

Prune-belly syndrome: an autopsy case report

Prune-belly syndrome (PBS) is a rare congenital anomaly characterized by a spectrum of mild-to-severe presentations of urinary tract malformations, deficient abdominal wall musculature, and cryptorchidism in male newborns or genital abnormalities in the female newborns. Currently, antenatal diagnosis is feasible with ultrasound examination, and treatment is based on case report experience. More recently, intrauterine management has been undertaken with encouraging results. The authors report a case of PBS diagnosed at the seventeenth gestation week, when ultrasonographic examination revealed the presence of ascites, distended bladder, thickened bladder wall and posterior urethral valve. The fetus was submitted to an intrauterine intervention at the nineteenth gestational week. Delivery occurred at 34 weeks of gestation and the newborn examination was consistent with PBS. On the second day of life, the newborn was submitted to abdominoplasty, colostomy, and orchiopexy. However, the outcome was unfavorable with respiratory failure and death on the fifteenth day of life. The autopsy confirmed the diagnosis of PBS, but the immediate cause of death was attributed to aspiration pneumonia.

Fetal lower urinary tract obstruction and its management

INTRODUCTION

Prenatal counselling in case of fetal obstructive uropathies still represents a clinical dilemma, despite ultrasound detection of lower urinary tract obstruction has greatly advanced during recent years as well as fetal intervention techniques.

MATERIALS AND METHODS

A systematic review of the relevant literature on the topic was performed, with a special focus on the role of antenatal ultrasound, in utero treatment and prognosis.

CONCLUSIONS

A clinico-diagnostic flow chart was developed, with the specific aim of aiding health care givers in the clinical management and the parental decision-making process.

Long-term renal and neurodevelopmental outcome in infants with LUTO, with and without fetal intervention

Congenital lower urinary tract obstruction (LUTO) is a heterogeneous group of pathologies, the most common being posterior urethral valves (PUV) or urethral atresia. The bladder neck obstruction in utero leads to a spectrum of disease including mild oligohydramnios with normal renal function to a picture of severe oligohydramnios associated with chronic obstructive macro/microcystic renal parenchymal disease leading to chronic renal impairment. These anomalies may be isolated or complex; the latter being associated with other structural or chromosomal abnormalities. If isolated, the congenital bladder neck obstruction may be amenable to in-utero therapy. In a significant proportion of babies affected by LUTO there is severe oligohydramnios (occurring before 20 weeks gestation) and associated with pulmonary hypoplasia, a scenario almost always associated with perinatal death. For those babies that survive the perinatal period there is a significant risk of renal impairment, often necessitating renal dialysis or transplantation in childhood. In addition, there may be other morbidities such as chronic filling anomalies of the bladder that may require treatment.

Effectiveness of fetal cystoscopy as a diagnostic and therapeutic intervention for lower urinary tract obstruction: a systematic review

OBJECTIVE

To determine the effectiveness of fetal cystoscopy in the prenatal diagnosis of and intervention for congenital lower urinary tract obstruction.

METHODS

This study was a literature search using MEDLINE, Embase, Cochrane Library, MEDION, Web of Science reference lists and contact with experts. All studies reporting on fetal cystoscopy in lower urinary tract obstruction with data for a 2 × 2 table were selected for review. No language restrictions were applied. There was independent selection of studies, data extraction and quality assessment by two reviewers. Peto odds ratios were calculated as a summary measure of effect.

RESULTS

A total of 2071 citations were identified and 66 papers selected for detailed evaluation, from which four papers with a total of 63 patients were selected for inclusion. Two papers had results for the use of cystoscopy in diagnosis, showing that fetal cystoscopy altered the ultrasound diagnosis of the underlying pathology in 36.4 and 25.0% of fetuses, respectively. Compared to no treatment, fetal cystoscopic intervention demonstrated an odds ratio for improved perinatal survival of 20.51 (95% CI, 3.87-108.69). However, comparing vesicoamniotic shunt (VAS) with fetal cystoscopy there appeared to be no significant improvement in the perinatal survival odds ratio of 1.49 (95% CI, 0.13-16.97). These results had wide CIs and for cystoscopy vs. VAS, all results crossed the line of no effect.

CONCLUSION

There is little published evidence for the effectiveness of therapeutic fetal cystoscopy as an intervention for congenital lower urinary tract obstruction and the quality of this evidence is poor. It should thus be considered to be an 'experimental intervention' and subjected to further investigation.

Early fetal cystoscopy for first-trimester severe megacystis

OBJECTIVES

To report the feasibility of early fetal cystoscopy for the prenatal diagnosis and therapy of severe first-trimester megacystis.

METHODS

Between January 2008 and February 2010, early fetal cystoscopy at 16 weeks of gestation was offered to 15 patients whose fetuses presented with severe first-trimester megacystis. All infants were followed up for 6-12 months after birth. Autopsy was always performed whenever fetal or neonatal deaths occurred.

RESULTS

Seven patients decided to undergo fetal therapy, and eight elected to continue with expectant observation. One fetus died before early fetal cystoscopy was performed. Therefore, six fetuses underwent early fetal cystoscopy. Urethral atresia was diagnosed in three fetuses during fetal cystoscopy and confirmed at autopsy following termination of pregnancy at 19-20 weeks in all cases. Posterior urethral valves were diagnosed and successfully fulgurated by laser during early cystoscopy in three fetuses, two of which survived with normal renal and bladder function after birth; the remaining fetus had a postnatal diagnosis of megacystis-microcolon intestinal hypoperistalsis syndrome and died neonatally. In the expectantly managed group, no survivals were observed, even among cases with 'isolated' posterior urethral valves.

CONCLUSIONS

Percutaneous early fetal cystoscopy is feasible for prenatal diagnosis and therapy of severe megacystis.

Fetal surgery for severe lower urinary tract obstruction

Fetal interventions have been proposed for treatment of severe lower urinary tract obstruction (LUTO), as this condition is associated with high rates of perinatal mortality and postnatal renal impairment. The rationale for in utero treatment for those cases is based on the possibility of relieving the obstruction, improving the amniotic fluid volume, and preventing renal and bladder damage. Candidates for fetal intervention should be rigorously selected based on the confirmation of severe LUTO (dilated bladder and bilateral hydronephrosis), oligohydramnios or anyhydramnios and 'favorable' fetal urinalysis (dependent on gestational age). Nowadays there are two different therapeutic options with specific technical approaches. Vesico-amniotic shunting is an easier procedure, but with a higher frequency of related complications. Fetal cystoscopy can be used for diagnostic purpose and for treatment of posterior urethral valves, with suggestive advantage of allowing a more physiological release of the obstruction. According to the literature, estimated survival rates and postnatal normal renal function frequencies are approximately 40 and 50% after vesico-amniotic shunting and 75 and 65% after fetal cystoscopy, respectively.

Feasibility of vesicoamniotic shunt insertion in an inanimate model: comparison of fetoscopic and ultrasound-guided techniques

OBJECTIVES

To determine the feasibility of fetoscopic vesicoamniotic shunt insertion (F-VASI) in an inanimate model and to compare F-VASI to ultrasound (US)-guided VASI (US-VASI) with respect to accuracy of shunt placement and overall success rate.

METHODS

An inanimate second-trimester fetus with a replaceable bladder balloon was suspended in a pressurized water tank and localized with US. Fetal position was randomized, the operator was blinded and a 5-Fr Harrison Shunt® decompressed the bladder in both groups. Thirty shunt insertions were performed per group.

RESULTS

Procedure time was longer for F-VASI (15.0 vs. 2.8 min, p < 0.05), although it decreased with practice. F-VASI and US-VASI were similar for adequate depth of insertion (27/30 vs. 27/30, p = 1.0), placement within 1 cm of midline (27/30 vs. 25/30, p = 0.42), bladder puncture (28/30 vs. 28/30, p = 1.0), and overall success rate (27/30 vs. 23/30, p = 0.3).

CONCLUSIONS

F-VASI is feasible in an inanimate model. Overall success rate was similar between the groups, although procedure time was longer for F-VASI. Further study is required to determine whether shunt migration is decreased with F-VASI.

In utero management of fetal lower urinary tract obstruction with a novel shunt: a landmark development in fetal therapy

OBJECTIVE

Fetal lower urinary tract obstruction occurs in approximately 1:3000 pregnancies. Standard vesicoamniotic shunting is fraught with malfunctioning in upto 60% of cases. We hereby report the development and application of a novel and reliable shunt.

MATERIALS AND METHODS

Patients with lower urinary tract obstruction were offered the novel shunt among other standard management options. Shunting involved the placement of a double disk device with a standard double pig-tail catheter. All patients signed informed consent.

RESULTS

Four patients have been treated with the novel shunt. In three patients, shunting was conducted between the bladder and amniotic cavity. In one patient (dichorionic-discordant twins) with a prior dislodged shunt causing urinary ascites, shunting was conducted between the peritoneal and amniotic cavities ('bridge shunt'). In all cases, correct and stable shunt placement was confirmed endoscopically and sonographically and in all patients, the fetal bladder remains effectively drained.

CONCLUSION

Reliable and effective vesico or peritoneoamniotic shunting can be achieved with the novel shunt. This shunt cannot become dislodged into the peritoneal cavity or the amniotic cavity, and cannot be pulled out by the fetus. Further experience is necessary to determine the risks and benefits of this novel treatment for fetal lower urinary tract obstruction.

The making of fetal surgery

Fetal diagnosis prompts the question for fetal therapy in highly selected cases. Some conditions are suitable for in utero surgical intervention. This paper reviews historically important steps in the development of fetal surgery. The first invasive fetal intervention in 1963 was an intra-uterine blood transfusion. It took another 20 years to understand the pathophysiology of other candidate fetal conditions and to develop safe anaesthetic and surgical techniques before the team at the University of California at San Francisco performed its first urinary diversion through hysterotomy. This procedure would be abandoned as renal and pulmonary function could be just as effectively salvaged by ultrasound-guided insertion of a bladder shunt. Fetoscopy is another method for direct access to the feto-placental unit. It was historically used for fetal visualisation to guide biopsies or for vascular access but was also abandoned following the introduction of high-resolution ultrasound. Miniaturisation revived fetoscopy in the 1990 s, since when it has been successfully used to operate on the placenta and umbilical cord. Today, it is also used in fetuses with congenital diaphragmatic hernia (CDH), in whom lung growth is triggered by percutaneous tracheal occlusion. It can also be used to diagnose and treat urinary obstruction. Many fetal interventions remain investigational but for a number of conditions randomised trials have established the role of in utero surgery, making fetal surgery a clinical reality in a number of fetal therapy programmes. The safety of fetal surgery is such that even non-lethal conditions, such as myelomeningocoele repair, are at this moment considered a potential indication. This, as well as fetal intervention for CDH, is currently being investigated in randomised trials.

Prenatal management of urogenital disorders

Antenatal sonography has markedly increased the detection of urogenital anomalies, including those conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder outlet obstruction but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida, can be corrected in utero, with improvements in hydrocephalus seen along with a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally now possible. As further techniques evolve to correct underlying disease processes, it becomes important to critically assess the therapies, particularly with long-term outcome data.

Fetal cystoscopy for severe lower urinary tract obstruction--initial experience of a single center

OBJECTIVE

To report the experience with fetal cystoscopy and laser fulguration of posterior urethral values (PUV) for severe lower urinary tract obstruction (LUTO).

METHODS

Between July 2006 and December 2008, fetal cystoscopy was offered to 23 patients whose fetuses presented with severe LUTO, favorable urinary analysis and gestational age <26 weeks. Fetal urinary biochemistry was evaluated before and after cystoscopy. All infants were followed 6-12 months after birth. Abnormal renal function was defined when serum creatinine higher than 50 micromol/L (2 Standard Deviation) or the necessity of dialysis or renal transplantation. Autopsy was always performed whenever fetal or neonatal deaths occurred.

RESULTS

Eleven patients decided to undergo fetal therapy and 12 elected to continue with expectant observation. There was no difference between both groups in gestation age at diagnosis and referral examinations. Urethral atresia was diagnosed in 4/11 (36.4%) fetuses by fetal cystoscopy. At 26 weeks, fetuses that were managed expectantly presented with worse urinary biochemistry results (p < 0.05). Survival rates and percentage of infants with normal renal function were significantly higher in the cystoscopic group than in the expectant group (p < 0.05).

CONCLUSIONS

Percutaneous fetal cystoscopy is feasible using a thinner special cannula for prenatal diagnosis and therapy of LUTO. Prenatal laser ablation of the PUV under cystoscopy may prevent renal function deterioration improving postnatal outcome.

Fetal surgery is a clinical reality

An increasing number of fetal anomalies are being diagnosed prior to birth, some of them amenable to fetal surgical intervention. We discuss the current clinical status and recent advances in endoscopic and open surgical interventions. In Europe, fetoscopic interventions are widely embraced, whereas the uptake of open fetal surgery is much less. The indications for each access modality are different, hence they cannot substitute each other. Although the stage of technical experimentation is over, most interventions remain investigational. Today there is level I evidence that fetoscopic laser surgery for twin-to-twin transfusion syndrome is the preferred therapy, but this operation actually takes place on the placenta. In terms of surgery on the fetus, an increasingly frequent indication is severe congenital diaphragmatic hernia as well as myelomeningocele. Overall maternal safety is high, but rupture of the membranes and preterm delivery remain a problem. The increasing application of fetal surgery and its mediagenicity has triggered the interest to embark on fetal surgical therapy, although the complexity as well as the overall rare indications are a limitation to sufficient experience on an individual basis. We plead for increased exchange between high volume units and collaborative studies; there may also be a case for self-regulation. Inclusion of patients into trials whenever possible should be encouraged rather than building up casuistic experience.

Fetal thoracic and bladder shunts

Congenital obstructive lesions involving the bladder and the lung can lead to serious complications for the newborn. The in-utero placement of a diverting shunt in the fetal bladder or thoracic cavity can decrease the morbidity and mortality associated with these obstructive conditions. This review focuses on the indications for prenatal evaluation, technique, and outcomes for those fetuses with a lower urinary tract obstruction, congenital pleural effusion or macrocystic congenital cystic adenomatoid malformation after placement of a vesicoamniotic or thoracoamniotic shunt.

Fetal lower urinary tract obstruction

The authors present an overview of the prenatal diagnosis, evaluation, contemporary intervention, and antenatal management of lower urinary tract obstruction. They review early experimental models that confirmed the relation between urinary tract obstruction and renal fibrocystic dysplasia and that early in utero relief of the obstruction could prevent irreversible renal injury. Subsequent studies of the electrolyte and protein concentrations in fetal urine from human cases established prognostic threshold values and helped to develop an algorithm to select candidates for antenatal therapy. Although shunting has improved survival, long-term morbidities remain a significant challenge.

Fetal surgery

Fetal surgery has emerged from the realm of medical curiosity into an exciting, multidisciplinary specialty now capable of improving patient outcomes for a wide variety of diseases. Recent advances allow prenatal providers to both accurately diagnose and treat many fetal anomalies while maintaining maternal safety. As the initial postnatal health care providers to the majority of these newborns, neonatologists need to be familiar with some of the more recent state-of-the-art procedures currently being used. In this review, the authors discuss the prenatal evaluation process and various operative approaches (ie, open hysterotomy, fetoscopy, and percutaneous) to conduct fetal surgery. They then analyze the effectiveness of some of the more established and experimental prenatal therapies that are being performed for a number of fetal anomalies, including twin-twin transfusion syndrome, thoracic malformations, airway obstruction, congenital diaphragmatic hernia, myelomeningocele, and aortic valve stenosis.

Congenital urinary tract obstruction

Congenital urinary tract obstruction is a heterogenous condition with a varying natural history. Accurate diagnosis within the late-first and second trimesters allows for counselling of the parents and planning of multi-disciplinary care for the pregnancy and newborn. Antenatal investigations to predict postnatal renal function are of varying accuracy. However, some factors have been shown to be predictive of poor outcome in terms of renal function at birth and infancy. There is the possibility of in-utero intervention in these fetuses.

Vesicoamniotic shunting for fetal lower urinary tract obstruction: an overview

Efficacy and complications of prenatal in utero treatment

Current diagnosis and management of fetal genitourinary abnormalities

Prenatal assessment with ultrasonography provides excellent imaging of fluid-filled structures (eg, hydronephrosis, renal cysts, and dilated bladder) and renal parenchyma. This information allows for the generation of a differential diagnosis, identification of associated anomalies, and assessment of the prenatal and postnatal risks of a given anomaly. This enhances parental education and prenatal and postnatal planning. This article discusses the current methods of diagnosis and management of fetal genitourinary anomalies, and also the postnatal evaluation and treatment of these conditions.

Impact of prenatal urinomas in patients with posterior urethral valves and postnatal renal function

OBJECTIVE

Posterior urethral valves (PUV) are a common cause of lower urinary tract obstruction. Renal failure occurs in approximately one third of the cases. It is debated whether urinoma formation is a protective mechanism to reduce pressure-related impairment of renal function. The aim of our study was to determine if urinoma formation is able to preserve renal function on the side of the urinoma.

METHODS

Five male patients diagnosed with posterior urethral valves and uni- or bilateral urinoma formation were reviewed. Renal function was assessed by serum creatinine level at days 4-7 and at two months, in addition to dimercaptosuccinylacid (DMSA) scintigraphy at 4-6 weeks postnatal age.

RESULTS

Impaired renal function occurred unilaterally in four patients, two had bilateral urinoma formation, and the other two boys presented with unilateral urinoma, one with preserved renal function ipsilateral to the urinoma and the other on the contralateral side. Urinary ascites was detected in three patients, all underwent antenatal centesis.

CONCLUSIONS

No association was found between renal function and urinoma formation in patients with PUV.