Pediatric Surgery

Diagnosis and Management

Bearbeitet von Prem Puri, Michael E Höllwarth

1. Auflage 2009. Buch. xxiv, 998 S. Hardcover ISBN 978 3 540 69559 2 Format (B x L): 20,3 x 27,6 cm Gewicht: 2569 g

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Kokila Lakhoo

Contents 2.1 Introduction

2.1 Introduction ...... 9 Paediatric surgeons are often called to counsel parents 2.2 Congenital Malformation ...... 10 once a surgical abnormality is diagnosed on a prenatal scan. The referral base for a paediatric surgeon now 2.3 Prenatal Diagnosis ...... 10 includes the perinatal period. Expertise in surgical cor- 2.3.1 Ultrasound Examination ...... 10 rection of congenital malformations may favourably 2.4 Invasive Diagnostic Tests ...... 11 infl uence the perinatal management of prenatally diag- 2.4.1 Amniocentesis ...... 11 nosed anomalies by changing the site of delivery for 2.4.2 Chorionic Villous Sampling (CVS) ...... 11 immediate postnatal treatment; altering the mode of 2.4.3 Prenatal Maternal Serum Screening ...... 11 2.4.4 Fetal Blood Sampling (FBS)...... 12 delivery to prevent obstructed labour or haemorrhage; 2.4.5 Fetal Surgery ...... 12 early delivery to prevent ongoing fetal organ damage; 2.4.6 Genetic Diagnoses ...... 12 or treatment in utero to prevent, minimise or reverse 2.4.7 Future Developments ...... 12 fetal organ injury as a result of a structural defect. 2.5 Specifi c Surgical Conditions ...... 12 Favourable impact of prenatal counselling has been 2.5.1 Congenital Diaphragmatic confi rmed to infl uence the site of delivery in 37% of Hernia (CDH) ...... 12 cases, change the mode of delivery in 6.8%, reverse 2.5.2 Cystic Lung Lesions ...... 13 the decision to terminate a pregnancy in 3.6% and 2.6 Abdominal Wall Defects ...... 14 infl uence the early delivery of babies in 4.5%. 2.6.1 Exomphalos ...... 14 Counselling parents about prenatally suspected 2.6.2 Gastroschisis ...... 15 surgically correctable anomalies should not be solely performed by obstetricians or paediatricians. Similarly 2.7 Tracheo-Oesophageal Fistula (TOF) and Oesophageal Atresia (OA) ...... 16 the paediatric surgeon performing these prenatal consultations must be aware of differences between 2.8 Gastrointestinal Lesions ...... 16 the prenatal and postnatal natural history of the 2.9 Sacrococcygeal Teratoma ...... 16 anomaly. There is often a lack of understanding of the natural history and prognosis of a condition presen- 2.10 Renal Anomalies ...... 17 2.10.1 Upper Urinary Tract Obstruction ...... 17 ting in the newborn and the same condition diagnosed 2.10.2 Lower Urinary Tract Obstruction ...... 17 prenatally. The diagnosis and management of complex fetal 2.11 Conclusion ...... 18 anomalies require a team effort by obstetricians, neo- Further Reading ...... 18 natologists, genetecists, paediatricians and paediatric surgeons to deal with all the maternal and fetal complexities of a diagnosis of a structural defect. This team should be able to provide information to pros- pective parents on fetal outcomes, possible interventions, appropriate setting, time and route of delivery and

P. Puri and M. Höllwarth (eds.), Pediatric Surgery: Diagnosis and Management, 9 DOI: 10.1007/978-3-540-69560-8_2, © Springer-Verlag Berlin Heidelberg 2009 10 Part I General expected postnatal outcomes. The role of the surgical with maternal diabetes, hypertension, genetic disorders, consultant in this team is to present information raised alpha fetoprotein, etc. High-risk pregnancies regarding the prenatal and postnatal natural history of may be offered further invasive diagnostic investiga- an anomaly, its surgical management and the long- tions such as amniocentesis or chorionic villous term outcome. sampling. Structural abnormalities diffi cult to defi ne on ultrasound such as hindbrain lesions or in the presence of oligohydramnios are better imaged on ultra fast magnetic resonance imaging. With the 2.2 Congenital Malformation increasing range of options and sophistication of diag- nostic methods, parents today are faced with more Congenital malformations account for one of the major information, choice and decisions than ever before, causes of perinatal mortality and morbidity. Single which can create as well as help to solve dilemmas. major birth defects affect 3% of newborns and multiple The different tests and screening procedures com- defects affect 0.7% of babies. The prenatal hidden monly in use are outlined below. mortality is higher since the majority abort spontane- ously. Despite improvements in perinatal care, serious birth defects still account for 20% of all deaths in the newborn period and an even greater percentage of 2.3.1 Ultrasound Examination serious morbidity later in infancy and childhood. The major causes of congenital malformation are chromo- Ultrasound scan is routinely performed at 18–20 weeks somal abnormalities, mutant genes, multifactorial dis- gestation as part of the prenatal screening for all preg- orders and teratogenic agents. nancies in England and Wales. Older mothers are rou- tinely screened and in addition are offered invasive testing. Pregnancies with maternal risk factors such as raised alpha fetoprotein levels, genetic disorders and 2.3 Prenatal Diagnosis family history of chromosomal abnormalities or mono- chorionic twins that carry a high risk for chromosomal Prenatal diagnosis has remarkably improved our under- anomalies are offered scans in the fi rst trimester. standing of surgically correctable congenital malfor- Abnormalities such as diaphragmatic hernia may be mations. It has allowed us to infl uence the delivery detected as early as 11 weeks of gestation. First trimes- of the baby, offer prenatal surgical management and ter scans are also useful for accurately dating pregnan- discuss the options of termination of pregnancy for cies and defi ning chorionicity in multiple pregnancies. seriously handicapping or lethal conditions. Antenatal More recently, nuchal translucency (NT) measure- diagnosis has also defi ned an in utero mortality for ments have emerged as an independent marker of chro- some lesions such as diaphragmatic hernia and sacro- mosomal abnormalities with a sensitivity of 60%, coccygeal teratoma so that true outcomes can be mea- structural anomalies (particularly cardiac defects) and sured. Prenatal ultrasound scanning has improved for some rare genetic syndromes. It involves measuring since its fi rst use 30 years ago, thus providing better the area at the back of the fetal neck at 11–14 weeks of screening programmes and more accurate assessment gestation (Fig. 2.1). The mechanisms by which some of fetal anomaly. Screening for Down’s syndrome may abnormalities give rise to this transient anatomical now be offered in the fi rst trimester (e.g. nuchal scan change of nuchal translucency are poorly understood. combined test) or second trimester (e.g. Triple blood Although some abnormalities can be seen at the time of test). Better resolution and increased experience with the nuchal scan (11–14 weeks), most are detected at the ultrasound scans has led to the recognition of ultra- 18–20 week anomaly scan. Some abnormalities such as sound soft markers that have increased the detection gastroschisis have a higher detection rate on a scan than rate of fetal anomalies but at the expense of higher others, for example, cardiac abnormalities. false positive rates. If the nuchal translucency measurement is increased Routine ultrasound screening identifi es anomalies and the karyotype is normal, there is a higher risk for a and places these pregnancies in the high-risk categories cardiac anomaly and these high-risk fetuses may be 2 K. Lakhoo ● Fetal Counselling for Surgical Congenital Malformations 11

obtained is dependent on the expertise and experience of the person performing the scan. In a recent study, congenital anomalies noted at birth were diagnosed on prenatal scan in 64% of cases with 0.5% opting for termination.

Nuchal thickening 2.4 Invasive Diagnostic Tests

Amniocentesis and chorionic villous sampling (CVS) are the two most commonly performed invasive diag- nostic tests. Fig. 2.1 Nuchal translucency scan

referred for fetal echocardiography, which provides bet- 2.4.1 Amniocentesis ter prenatal cardiac assessment than the routine screen- ing scan. Ultrasound surveillance is essential during the Amniocentesis is commonly used for detecting chromo- performance of invasive techniques such as amniocente- somal abnormalities and less often for molecular stud- sis, CVS and shunting procedures. It is also useful for ies, metabolic studies and fetal infection. It is performed assessing fetal viability before and after such proce- after 15 weeks of gestation and carries a low risk of fetal dures. Some abnormalities such as tracheo-oesophageal injury or loss (0.5–1%). Full karyotype analysis takes fi stula, bowel atresia, diaphragmatic hernia and hydro- approximately 2 weeks but newer RAPID techniques cephaly may present later in pregnancy and thereby may using FISH (fl uorescent in situ hybridisation) or PCR not be detected during the routine 18-weeks scan. (polymerase chain reaction) can give limited (usually Overall, around 60% of structural birth defects are for trisomies 21,18,13) results within 2–3 days. detected prenatally but the detection rate varies from 0% (isolated cleft palate) to close to 100% (gastroschi- sis) depending on the defect. True wrong diagnoses are rare but false positive diagnoses do occur; some are 2.4.2 Chorionic Villous Sampling (CVS) due to natural prenatal regression, but most are due to ultrasound “soft markers”. CVS is the most reliable method for fi rst trimester Ultrasound “soft markers” are changes noted on diagnosis and may be performed at 10–14 weeks of prenatal scan that are diffi cult to defi ne. Examples gestation. The test involves ultrasound-guided biopsy are echogenic bowel, hydronephrosis and nuchal thick- of the chorionic villi. The added risk for fetal loss is ening. Their presence creates anxiety among sonogra- approximately 1–2%. The samples obtained may be phers because the finding may be transient with subjected to a variety of tests including full karyotype, no pathological relevance or may be an indicator of rapid karyotyping (FISH—PCR), enzyme analysis or signifi cant anomalies such as chromosomal abnorma- molecular studies. Approximate timing of chromo- lities, cystic fi brosis (echogenic bowel), Down’s syn- somal results is 1–2 weeks for karyotyping and 2–3 drome (nuchal thickening) or renal abnormalities days for FISH and PCR. (hydronephrosis). Once soft markers are detected, the dilemma faced by obstetricians is whether they should be reported or further invasive tests offered. Reporting these markers has increased detection rates at the 2.4.3 Prenatal Maternal Serum Screening expense of high false positive rates. Ultrasound is routinely performed as a prenatal Interest in detecting circulating fetal cells in maternal screening test. The reliability of the information blood for diagnostic purposes has grown since the 12 Part I General advent of fl uorescence-activated cell sorting (FACS). 2.4.7 Future Developments The observation of high levels of AFP (alpha fetopro- tein) in the amniotic fl uid of pregnancies complicated The aim of prenatal diagnosis and testing is to ensure by open neural tube defects (NTDs) popularised this 100% accuracy without fetal loss or injury and no test. However, with increasing accuracy of ultrasound maternal risk. National plans to improve Down’s diagnosis, maternal serum screening of AFP solely for screening using ultrasound and biochemical combina- identifi cation of NTDs cannot be justifi ed. The more tion tests are now in place in the UK. Research into popular maternal serum screening test is the triple test new markers for chromosomal abnormalities is ongo- (HCG, AFP, oestrogen) used in combination with the ing. The fetal nasal bone is one such example, which nuchal scan. may assist, in detecting babies with chromosomal abnormalities. Management of Rhesus disease is showing promise whereby fetal blood groups may be determined from 2.4.4 Fetal Blood Sampling (FBS) maternal blood samples through detection of free fetal DNA. The search for fetal components in maternal Rapid karyotyping of CVS and amniotic fl uid samples blood is an exciting and expanding fi eld of research FISH and PCR has replaced fetal blood sampling for since past and present efforts to isolate and use them many conditions. However, FBS is still required for for diagnosis have met with little success. Rapid detec- the diagnosis and treatment of haematological condi- tion techniques versus traditional cultures for karyo- tions and some viral infections. When required it is typing are currently under debate. best performed by ultrasound guided needle sampling Three-dimensional images from new ultrasound after 18 weeks of gestation rather than the more inva- machines may have a useful role in diagnosis and assess- sive fetoscopic technique. Mortality from this proce- ment of facial deformities such as cleft lip and palate. dure is reported to be 1–2%. Magnetic resonance imaging (MRI) may assist in better defi ning some lesions diffi cult to view on conventional prenatal scanning such as the presacral teratoma, poste- rior urethral valves in the presence of oligohydramnios 2.4.5 Fetal Surgery and hindbrain lesions. At present, MRI is unlikely to replace conventional ultrasound scans. There is a spectrum of interventions ranging from sim- ple aspiration of cysts to open fetal surgery. Minimally invasive techniques such as ablation of vessels in sacrococcygeal teratoma, fetoscopic ablation of poste- 2.5 Specifi c Surgical Conditions rior urethal valves, tracheal occlusion for congenital diaphragmatic hernia, etc. are currently under trial. 2.5.1 Congenital Diaphragmatic Hernia However, laser ablation in twin-to-twin transfusion is now well established. (CDH)

CDH accounts for 1 in 3,000 live birth and challenges the neonatologist and paediatric surgeons in the man- 2.4.6 Genetic Diagnoses agement of this high-risk condition. Mortality remains high (more than 60%) when the “hidden” mortality of Antenatal detection of genetic abnormalities is increa- in utero death and termination of pregnancy are con- sing especially in high-risk pregnancies. Previously sidered. Lung hypoplasia and pulmonary hypertension undiagnosed conditions such as cystic fibrosis, account for most deaths in isolated CDH newborns. Beckwith-Wiedemann syndrome, Hirshsprung’s dis- Associated anomalies (30–40%) signify a grave prog- ease, sickle cell disease, etc. may be detected prena- nosis with a survival rate of less than 10%. tally following invasive testing and genetic counselling In the UK, most CDHs are diagnosed at the 20-week and assessment offered early in pregnancy. anomaly scan with a detection rate approaching 60%, 2 K. Lakhoo ● Fetal Counselling for Surgical Congenital Malformations 13 although as early as 11 weeks gestation has been lesions containing features of both are common cystic reported. Magnetic resonance imaging (MRI) has a lung lesions noted on prenatal scan. Less common useful role in accurately differentiating CDH from lung anomalies include bronchogenic cysts, congenital cystic lung lesions and may be useful in measuring lobar emphysema and bronchial atresia. Congenital fetal lung volumes as a predictor of outcome. Cardiac cystic lung lesions are rare anomalies with an inci- anomalies (20%), chromosomal anomalies of trisomy dence of 1 in 10,000 to 1 in 35,000. 13 and 18 (20%) and urinary, gastrointestinal and neu- Prenatal detection rate of lung cysts at the routine rological (33%) anomalies can co-exist with CDH and 18–20 week scan is almost 100% and may be the com- should be ruled out by offering the patient fetal monest mode of actual presentation. Most of these echocardiogram, amniocentesis and detailed anomaly lesions are easily distinguished from congenital dia- scans. In these CDH patients, early detection, liver in phragmatic hernia; however, sonographic features of the chest, polyhydramnios and fetal lung head ratio CCAM or BPS are not sufficiently accurate and (LHR) of less than 1 are implicated as poor predictors correlate poorly with histology. Magnetic resonance of outcome. In these patients with poor prognostic imaging (MRI), though not routinely used, may pro- signs, fetal surgery for CDH over the last 2 decades vide better defi nition for this condition; however, inac- has been disappointing; however, benefi t from fetal curacies were reported in 11% of cases. intervention with tracheal occlusion (FETO) awaits Bilateral disease and hydrops fetalis are indicators randomised studies. A favourable outcome in CDH of poor outcome, whereas mediastinal shift, polyhy- with the use of antenatal steroids has not been resolved dramnios and early detection are not poor prognostic in the clinical settings. Elective delivery at a specia- signs. In the absence of termination, the natural fetal lised centre is recommended with no benefi t from demise of antenatally diagnosed cystic lung disease is caesarean section. 28%. It is well documented that spontaneous involu- Post-natal management is aimed at reducing baro- tion of cystic lung lesions can occur but complete trauma to the hypoplastic lung by introducing high post-natal resolution is rare, and apparent spontaneous frequency oscillatory ventilation (HFOV) or permissive “disappearance” of antenatally diagnosed lesions should hypercapnea, and treating severe pulmonary hyperten- be interpreted with care, as nearly half of these cases sion with nitric oxide. No clear benefi ts for CDH with subsequently require surgery. ECMO (extra corporeal membrane oxygenation) have In only 10% of cases the need for fetal intervention been concluded in a 2002 Cochrane ECMO study. arises. The spectrum of intervention includes simple Surgery for CDH is no longer an emergency centesis of amniotic fl uid, thoracoamniotic shunt procedure. Delayed repair following stabilisation is placement, percutaneous laser ablation and open fetal employed in most paediatric surgical centres. Primary surgical resection. Maternal steroid administration has repair using the trans-abdominal route is achieved in also been reported to have a benefi cial effect on some 60–70% of patients with the rest requiring a prosthetic CCAMs although the mechanism is unclear. A large patch. Complications of sepsis or reherniation with cystic mass and hydrops in isolated cystic lung lesions prosthetic patch requiring revision are recorded in 50% are the only real indication for fetal intervention. of survivors. Minimally invasive techniques have been Normal vaginal delivery is recommended unless successful in repairing diaphragmatic defects in “sta- maternal conditions indicate otherwise. Large lesions ble” infants. are predicted to become symptomatic shortly after Long-term survivors of CDH are reported to develop birth (as high as 45% in some series); thus, delivery at chronic respiratory insuffi ciency (48%), gastro-oesophageal a specialised centre would be appropriate. However, refl ux (89%) and neurodevelopment delay (30%). smaller lesions are less likely to be symptomatic at birth and could be delivered at the referring institution with follow up in a paediatric surgery clinic. Post-natal management is dictated by clinical status 2.5.2 Cystic Lung Lesions at birth. Symptomatic lesions require urgent radiologi- cal evaluation with chest radiograph and ideally CT Congenital cystic adenomatoid malformations (CCAMs), scan (Fig. 2.2) followed by surgical excision. In asymp- bronchopulmonary sequestrations (BPS) or “hybrid” tomatic cases, post-natal investigation consists of chest 14 Part I General

Fig. 2.2 Prenatal scan and post-natal radiological features of CCAM

CT scan within 1 month of birth, even if regression or 2.6 Abdominal Wall Defects resolution is noted on prenatal scanning. Plain radiog- raphy should not be relied on, because it will miss and Exomphalos and gastroschisis are both common but underestimate many lesions. distinct abdominal wall defects with an unclear aetiol- Surgical excision of post-natal asymptomatic lesions ogy and a controversial prognosis. Attention may be remains controversial, with some centres opting for drawn to their presence during the second trimester conservative management. The approach to treating because of raised maternal serum alpha-fetoprotein this asymptomatic group has evolved in some centres, level or abnormal ultrasound scans. whereby a CT scan is performed within 1 month post birth, followed by surgery before 6 months of age due to the inherent risk of infection and malignant transfor- mation. Small lesions less than 3 cm may be managed 2.6.1 Exomphalos expectantly with annual CT scan, bearing in mind that the true resolution of these lesions is exceptional. Exomphalos is characteristically a midline defect, at Successful outcome of greater than 90% have been the insertion point of the umbilical cord, with a viable reported for these surgically managed asymptomatic sac composed of amnion and peritoneum containing lung lesions. herniated abdominal contents. Incidence is known to 2 K. Lakhoo ● Fetal Counselling for Surgical Congenital Malformations 15 be 1 in 4,000 live births. Associated major abnormali- ties that include trisomy 13, 18 and 21, Beckwith- Wiedemann syndrome (macroglossia, gigantism, exomphalos), Pentology of Cantrell (sternal, pericar- dial, cardiac, abdominal wall and diaphragmatic Dilated bowel of defect), cardiac, gastrointestinal and renal abnormali- Gastroschisis ties are noted in 60–70% of cases; thus, karyotyping, in addition to detailed sonographic review and fetal echocardiogram, is essential for complete prenatal screening. Fetal intervention is unlikely in this condi- tion. If termination is not considered, normal vaginal delivery at a centre with neonatal surgical expertise is recommended and delivery by caesarean section only is reserved for large exomphalos with exteriorised liver Fig. 2.3 Dilated bowel in gastroschisis to prevent damage. Surgical repair includes primary closure or a staged repair with a silo for giant defects. Occasionally Predicting outcome in fetuses with gastroschisis in vulnerable infants with severe pulmonary hypopla- based on prenatal ultrasound fi nding remains a chal- sia or complex cardiac abnormalities the exomphalos lenge. There is some evidence that maximum small may be left intact and allowed to slowly granulate bowel diameter may be predictive; however, thickened and epithelialise by application of antiseptic solution. matted bowel and Doppler measurements of the superior Post-natal morbidity occurs in 5–10% of cases. mesenteric artery are not accurate predictors of outcome. Malrotation and adhesive bowel obstruction does To reduce the rate of third trimester fetal loss, serial ultra- contribute to mortality in isolated exomphalos; how- sounds are performed to monitor the development of ever, the majority of these children survive to live bowel obstruction and delivery around 37 weeks recom- normal lives. mended at a centre with neonatal surgical expertise. Recently a randomised control trial has challenged elec- tive preterm delivery. Delivery by caesarean section has no advantage to normal vaginal route. Despite efforts to plan 2.6.2 Gastroschisis elective delivery, 50% of cases will require emergency cae- sarean section due to development of fetal distress. Gastroschisis is an isolated lesion that usually occurs Various methods of post-natal surgical repair on the right side of the umbilical defect with evis- include the traditional primary closure, reduction of ceration of the abdominal contents directly into the bowel without anaesthesia, reduction by preformed amniotic cavity. The incidence is increasing from silo, or by means of a traditional silo. Co-existing 1.66 per 10,000 births to 4.6 per 10,000 births affect- intestinal atresia could be repaired by primary anasta- ing mainly young mothers typically less than 20 mosis or staged with stoma formation. Variation in years old. Associated anomalies are noted in only achieving full enteral feeding due to prolonged gut 5–24% of cases with bowel atresia the most com- dysmotility is expected in all cases. mon co-existing abnormality. On prenatal scan with The long-term outcome in gastroschisis is depen- a detection rate of 100%, the bowel appears to be dent on the condition of the bowel. In uncomplicated free fl oating, and the loops may appear to be thick- cases the outcome is excellent in more than 90% of ened due to damage by amniotic fl uid exposure cases. The mortality of live born infants is 5% with causing a “peel” formation. Dilated loops of bowel further 5% suffering short bowel syndrome and 10% (Fig. 2.3) may be seen from obstruction secondary requiring surgery for adhesive bowel obstruction. Late to protrusion from a defect or atresia due to intesti- third trimester fetal loss should always be mentioned nal ischaemia. during fetal counselling. 16 Part I General

2.7 Tracheo-Oesophageal Fistula (TOF) 2.8 Gastrointestinal Lesions and Oesophageal Atresia (OA) The presence of dilated loops of bowel (>15 mm in Repair of TOF/OA is a condition that measures the length and 7 mm in diameter) on prenatal ultrasound skill of paediatric surgeons from trainees to indepen- scan is indicative of bowel obstruction. dent surgeons. The incidence is estimated at 1 in 3,000 Duodenal atresia has a characteristic “double bub- births. Prenatally, the condition may be suspected from ble” appearance on prenatal scan, resulting from the maternal polyhydramnios and absence of a fetal stom- simultaneous dilatation of the stomach and proximal ach bubble at the 20-week anomaly scan. Prenatal duodenum. Detection rate on second trimester anom- scan diagnosis of TOF/OA is estimated to be less than aly scan is almost 100% in the presence of polyhy- 42% sensitive with a positive predicted value of dramnios and the “double bubble” sign. Associated 56%. Additional diagnostic clues are provided by anomalies are present in approximately 50% of cases associated anomalies such as trisomy (13,18,21), with most notably trisomy 21 in 30% of cases, cardiac VACTERL sequence (vertebral, anorectal, cardiac, anomalies in 20% and the presence of VACTERL tracheo-oesophageal, renal, limbs) and CHARGE association (vertebral, anorectal, cardiac, tracheo- association (coloboma, heart defects, atresia choanae, oesophageal, renal and limbs). retarded development, genital hypoplasia, ear abnor- The incidence of duodenal atresia is 1 in 5,000 live mality). Associated anomalies are present in more births. The postnatal survival rate is >95% with asso- than 50% of cases and worsen the prognosis; hence, ciated anomalies, low birth weight and prematurity prenatal karyotyping is essential. Duodenal atresia contributing to the <5% mortality. Temporary delay in may co-exist with TOF/OA. The risk of recurrence in enteral feeding occurs due to the dysmotility in the subsequent pregnancies for isolated TOF/OA is less dilated stomach and duodenum. than 1%. Delivery is advised at a specialised centre Many bowel abnormalities may be noted on prena- with neonatal surgical input. tal scanning (dilated bowel, ascites, cystic masses, Postnatal surgical management is dependent on the hyperparistalsis, poyhydramnios and echogenic size and condition of the baby, length of the oesopha- bowel); however, none is absolutely predictive of post- geal gap and associated anomalies. Primary repair of natal outcome. Patients with obstruction frequently the oesophagus is the treatment of choice; however, if have fi ndings (especially in the third trimester) of not achieved, staged repair with upper oesophageal bowel dilatation, polyhydramnios and hyperparistalsis, pouch care and gastrostomy or organ replacement with but ultrasound is much less sensitive in diagnosing stomach or large bowel are other options. Associated anomalies in the large bowel than those in the small anomalies require evaluation and treatment. Advanced bowel. Since the large bowel is mostly a reservoir, with paediatric endosurgical centres may offer minimally no physiologic function in utero, defects in this region invasive thoracoscopic approach to the repair of TOF. such as anorectal malformations or Hirschsprung’s dis- Early outcome of a high leak rate and oesophageal ease are very diffi cult to detect. Bowel dilatation and stricture requiring dilatation in 50% of cases are echogenic bowel may be associated with cystic fi bro- expected where the anastamosis of the oesophagus is sis; therefore, all such fetuses should undergo post- created under tension. natal evaluation for this disease. Prenatally diagnosed Improved perinatal management and inherent struc- small bowel atresia does not select for a group with a tural and functional defects in the trachea and oesoph- worse prognosis and survival rates are 95–100%. agus indicate long-term outcome. In early life, growth of the child is reported to be below the 25th centile in 50% of cases, respiratory symptoms in two-thirds of 2.9 Sacrococcygeal Teratoma TOF/OA and gastro-oesophageal refl ux recorded in 50% of patients. Quality of life is better in the isolated Sacrococcygeal teratoma (SCT) is the commonest group with successful primary repair as compared to neonatal tumour accounting for 1 in 35,000 to 40,000 those with associated anomalies and delayed repair. births. Four types have been defi ned: 2 K. Lakhoo ● Fetal Counselling for Surgical Congenital Malformations 17

Type 1 external tumour with a small presacral in the cortex. In severe disease, lack of amniotic fl uid component may make ultrasound assessment of the renal tract dif- Type 2 external tumours with a large presacral fi cult and MRI may be helpful. Oligohydramnios is component indicative of poor renal function and poor prognosis Type 3 predominantly presacral with a small external owing to the associated pulmonary hypoplasia. component Urogenital anomalies co-exist with many other con- Type 4 entirely presacral genital abnormalities and amniocentesis should be offered in appropriate cases. It is estimated that 3% of The latter carry the worst prognosis due to delay infants will have an abnormality of the urogenital sys- in diagnosis and malignant presentation. Doppler tem and half of these will require some form of surgi- ultrasound is the diagnostic tool; however, fetal MRI cal intervention. provides better defi nition of the intrapelvic compo- nent. SCT is a highly vascular tumour and the fetus may develop high cardiac output failure, anaemia and ultimately hydrops with a mortality of almost 2.10.1 Upper Urinary Tract Obstruction 100%. Fetal treatment of tumour resection or abla- tion of the feeding vessel has been attempted in Antenatal hydronephrosis accounts for 0.6–0.65% hydropic patients. Caesarean section may be offered pregnancies. The most common cause of prenatal to patients with large tumours to avoid the risk of hydronephrosis is pelvi-ureteric junction obstruction bleeding during delivery. Post-natal outcomes fol- (PUJ), others being transient hydronephrosis, physio- lowing surgery in type 1 and 2 lesions are favour- logical hydronephrosis, multicystic kidney, posterior able; however, type 3 and 4 tumours may present urethral valves, ureterocele, ectopic ureter, etc. The with urological problems and less favourable out- prognosis of antenatally diagnosed hydronephrosis in comes. Long-term follow up with alpha fetoprotein unilateral disease and in renal pelvic diameter of and serial pelvic ultrasounds are mandatory to <10 mm is excellent. Spontaneous resolution is noted exclude recurrence of the disease. in 20% of patients at birth and 80% at 3 years of age. Only 17% of prenatally diagnosed hydronephrosis need surgical intervention. Post-natal management of hydronephrosis requires ultrasound at birth and at 1

2.10 Renal Anomalies month of age, and further evaluation with radiology and scintigraphy if an abnormality is suspected. The non-operative treatment of antenatally detected hydro- Urogenital abnormalities are among the commonest nephrosis has been carefully monitored over a 17-year disorders seen in the perinatal period and account for period, and from an analysis of six patient series the almost 20% of all prenatally diagnosed anomalies. conclusion is that this approach is safe. The routine use of antenatal ultrasound scans has resulted in the early detection of these conditions and in selected cases has led to the development of man- agement strategies including fetal intervention aimed 2.10.2 Lower Urinary Tract Obstruction at preservation of renal function. Two major issues are the indications for intervention in bladder outlet Posterior urethral valves (PUV) are the most com- obstruction and early pyeloplasty in infancy in cases mon cause for lower urinary tract obstruction in boys with hydronephrosis. with an incidence of 1 in 2,000 to 4,000 live male Prenatal evaluation of a dilated urinary tract is births. The diagnosis of PUV is suspected on the pre- based on serial ultrasound scans as well as measure- natal ultrasound fi nding of bilateral hydronephrosis ment of urinary electrolytes. Ultrasonography pro- associated with a thickened bladder and decreased vides measurements of the renal pelvis, assessment of amniotic fl uid volume. Serial fetal urine analysis may the renal parenchyma as well as the detection of cysts provide prognostic information on renal function. 18 Part I General

Prenatal diagnosis for patients with PUV is a poor natural history, the limitations of prenatal diagnosis, the prognostic sign with 64% incidence of renal failure detection of associated anomalies, the risks and indica- and transient pulmonary failure, compared to 33% in tions of fetal intervention programmes and postnatal the postnatally diagnosed patients. Pulmonary hyp- outcomes are essential to prenatal counselling. Prenatal oplasia secondary to oligohydramnios largely con- counselling is an essential component of paediatric sur- tributes to the morbidity and mortality from fetal gical practice and should be ensured in the training pro- urethral obstruction. Outcomes of fetal intervention gramme for future paediatric surgeons. with vesicoamniotic shunting or fetal cystoscopic ablation of urethal valve are still under review and await a multi-center trial. Further Reading Postnatal management includes ultrasound confi r- mation of the diagnosis, bladder drainage via a supra- Black R, Boyd P (2004) What’s new in prenatal diagnosis? pubic or urethral route and contrast imaging of the Trends Urol Gynaecol Sex Health 9:9–11 urethra. Primary PUV ablation, vesicostomy or ure- Boyd PA, Keeling JW (2007) Congenital abnormalities, prenatal terostomy are postnatal surgical options. The overall diagnosis and screening. In JW Keeling (ed) Fetal and Neonatal Pathology, 4th edn. Springer-Verlag, New York outcome from this disease is unfavourable. Harrison MR (2006) The fetus as a patient. In JL Grosfeld, JA O’Neill, EW Fonkalsrud, AG Coran (eds) Pediatric Surgery. Mosby, Philadelphia, pp 77–88 Lakhoo K (2007) Fetal counselling for congenital malforma- 2.11 Conclusion tions. PSI 23:509–519 Lakhoo K et al (2006) Best clinical practice: surgical conditions of the fetus and newborn. Early Hum Dev 82(5):281–324 The boundaries of paediatric surgical practice have been Puri P, Höllwarth ME (eds) (2006) Pediatric Surgery. Springer, extended by prenatal diagnosis. The care of patients Berlin, Heidelberg with surgically correctable defects can now be planned Sylvester K, Albanese CT (2005) The fetus as a patient. In prenatally with the collaborative effort of obstetricians, KT Oldham, PM Colombani, RP Foglia, MA Skinner, (eds) Principles and Practice of Pediatric Surgery. geneticists, neonatologists and paediatric surgeons. The Lippincott Williams & Wilkins, Philadelphia, PA, pp understanding of the specifi c surgical condition’s prenatal 27–47