Lower urinary outflow tract obstruction prevents an unborn baby from passing urine. This can reduce the volume of amniotic fluid, and can cause problems with development of the baby's lungs and kidneys. Fetal cystoscopy is a procedure in which a flexible endoscope (a special video camera) is inserted into the baby's bladder to identify the cause of obstruction and to guide treatment in order to allow urine to pass freely.

The National Institute for Health and Clinical Excellence is examining fetal cystoscopy for diagnosis and treatment of lower urinary outflow tract obstruction and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about fetal cystoscopy for diagnosis and treatment of lower urinary outflow tract obstruction..

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the preliminary recommendations
  
• the identification of factual inaccuracies
  
• additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
  
• The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the Institute's website (www.nice.org.uk/ipprogrammemanual).

Closing date for comments: 24 October 2006
Target date for publication of guidance: January 2007

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

Current evidence on the safety and efficacy of fetal cystoscopy for the diagnosis and treatment of lower urinary outflow tract obstruction is not adequate for this procedure to be used without special arrangements for consent and for audit or research.

Clinicians wishing to undertake fetal cystoscopy for diagnosis and treatment of lower urinary outflow tract obstruction should take the following actions.

• Inform the clinical governance leads in their Trusts.
• Ensure that the parents understand that the efficacy of the procedure is unproven and that the safety of the procedure is unknown. Clinicians should provide parents with clear written information. Use of the Institute’s information for patients (‘Understanding NICE guidance’) is recommended (available from www.nice.org.uk/IPG XXX publicinfo ). [[details to be completed at publication]]
• Audit and review clinical outcomes of all patients having fetal cystoscopy for diagnosis and treatment of lower urinary outflow tract obstruction (see section 3.1).

This procedure should only be performed in centres specialising in invasive fetal medicine and in the context of an appropriate multidisciplinary team, which should usually include a consultant in fetal medicine, a paediatric urologist, a neonatologist and a specialist midwife.

Further evidence is required, particularly in relation to appropriate case selection and outcomes. Reports should separate diagnostic cystoscopy from cystoscopy used with therapeutic procedures. The Institute may review the procedure upon publication of further evidence.

Lower urinary outflow tract obstruction in a fetus may be associated with various developmental abnormalities. The obstruction may result from a number of pathologies, including urethral atresia or posterior urethral valves, and can be partial or complete. Severe obstruction may lead to oligohydramnios and pulmonary and/or renal dysplasia. If severe, pulmonary and/or renal dysplasia may cause death soon after birth from respiratory or renal failure, respectively, or the baby may require ventilatory support and/or renal dialysis or kidney transplantation. The long-term prognosis for children who require dialysis or transplantation in infancy is very poor. F etal cystoscopy is therefore only indicated if there is preserved kidney function.

Alternative treatment options include: expectant management, termination of the pregnancy, repeat vesicocentesis, open fetal vesicotomy or vesico-amniotic shunt. Shunting aims to bypass the obstruction, with a view to definitive treatment of obstructive lesion(s) postnatally.

The procedure can be undertaken under maternal general anaesthesia or local anaesthetic infiltration. Under ultrasound guidance, a trocar or large-gauge needle is introduced through the maternal abdominal wall and uterine wall into the amniotic cavity, and then through the fetal abdomen into the fetal bladder. A flexible endoscope is introduced through the needle lumen or via a cannula. The bladder wall and uteric orifices, and the orifice of the posterior urethra, are inspected, and then the posterior urethra is entered. Posterior urethral valves may be manipulated with hydro-ablation (saline aspiration), guide-wire probing or may be ablated with electrocoagulation or laser. The success of treatment is assessed by Doppler imaging of fluid flow from the posterior urethra into the amniotic cavity.

In a case series, good visualisation of the fetal bladder was achieved in 92% (12/13) of fetuses. Among the fetuses with adequately visualised bladders, it was possible to enter the posterior urethra in 50% (6/12), and to identify the anatomical location of the urinary obstruction in 42% (5/12). All 13 fetuses were suspected of having posterior urethral valves but an alternative diagnosis was reached following cystoscopy in 15% (2/13) of fetuses. In one fetus with a pre-procedural diagnosis of urethral atresia, no urethral atresia was found at cystoscopy.

The data relating to cystoscopy-guided therapeutic interventions was of poor quality, originating from uncontrolled studies, and included limited data on clinical outcome. One case series demonstrated successful hydro-ablation of posterior urethral valves in 1 of 4 fetuses. In the same series, guide-wire manipulation of posterior urethral valves was successful in 5 of 9 fetuses with such a pathology. Overall in this case series, a normal renal outcome was achieved in 5 of 8 fetuses who survived to a live birth. A second case series reported that urethral patency and complete bladder emptying were achieved after guide-wire probing in 9% (1/11) of fetuses undergoing a cystoscopy-guided intervention. In the same series, the urethra was successfully cannulated in 27% (3/11) of fetuses.

The case series and case reports recorded survival in 0 of 1, 1 of 2, 69% (9/13) and 1 of 1 fetuses treated. For more details, refer to the sources of evidence (see appendix).

All the Specialist Advisers considered the procedure to be novel and of uncertain safety and efficacy.

In one case series, urinary ascites was reported in 38% (5/13) of fetuses undergoing cystoscopy and either hydro-ablation or guide-wire probing, requiring prenatal aspiration in 8% (1/13). In another case series of 13 fetuses, small unintentional perforation of the fetal bladder was noted during cystoscopy in 9% (1/11) of fetuses undergoing guide-wire cannulation of the urethra. Many of the fetuses included in the evidence had a number of comorbidities, and it is unclear whether the complications were a result of the procedure or the comorbidities.

In three case reports detailing four fetuses, premature rupture of the membranes occurred in one pregnancy on the third day after the procedure. This was treated with an amniopatch but the fetus died 3 days later. For more details, refer to the sources of evidence (see appendix).

The Specialist Advisers stated that adverse events include miscarriage, preterm delivery, urinary ascites, damage to the anterior abdominal wall or bladder, premature rupture of membranes and maternal infection.

It was noted that the instruments used in this procedure require further development

Further information

This guidance requires that clinicians undertaking the procedure make special arrangements for audit. The Institute has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

• 'Interventional procedure overview of fetal cystoscopy for diagnosis and treatment of lower urinary outflow tract obstruction', June 2006