Dysmorphism/congenital abnormality Flashcards
cleft lip/palate, diaphragmatic hernia, tracheoesophageal fistula, oesophageal atresia, biliary atresia, small bowel atresia, urinary tract anomalies, anorectal malformations, cryptorchidism
Describe the embryology of the umbilicus.
During development, umbilicus consists of 2 umbilical arteries (continuous with internal iliac arteries) and 1 umbilical vein (continuous with the falciform ligament/ducus venosus).
After birth, the cord dessicates and separates and the umbilical ring closes.
Name 4 umbilical disorders (with discharge).
- Omphalitis - infection with S.aureus; may be dangerous as can spread through umbilical veins to cause pyaemia and portal vein thrombosis; treat with topical and systemic antibiotics
- Umbilical granuloma - cherry lesions around umbilicus which may _bleed or have seropurulent discharg_e; treat with chemical cautery and topical silver nitrate
- Persistent urachus - urinary discharge from umbilicus when urachus which is attached to bladder persists; assoc. with other urogenital abnormalities
- Persistent vitello-intestinal duct - small bowel content discharge, rarely a complete persistence of the duct; persistence of part of the duct is called Meckel’ diverticulum; image with contrast and close surgically by laparotomy.
Name 2 umbilical disorders (no discharge).
Umbilical hernia - self resolve, rarely stragulate, more comon in premature infants
Paraumbilical hernia - defects in linea alba, edes of hernia more defined than of umbilical hernia, close spontaneously after 12 months - 3 years.
What is the management of an umbilical hernia found in an infant?
They will self-resolve by age of 3 years - if not surgery can be offered at 2-3 years if large(>1.5cm) and symptomatic or 4-5 years if small and asymptomatic.
What are the risk factors for umbilical hernia?
- Afro-Caribbean infants
- Down’s syndrome
- mucopolysaccharide storage diseases
Define biliary atresia.
A paediatric condition involving either obliteration or discontinuity within the extrahepatic biliary system wjocj results in the obstruction of flow of bile. Neonate then presents with cholestasis within a few days.
What are the types of biliary atresia?
- Type 1: patent proximal ducts but common duct obliterated
- Type 2: atresia of cystic duct and cystic structures in the porta hepatis
- Type 3: atresia of the left and right ducts to the level of the porta hepatis, occurs in >90% of cases
How common is biliary atresia?
- females> males
- neonates only - perinatal form presents within 2 weks of life and postnatal form presents within the first 2-8 weeks of life
- 1 in every 10,000-15,000 live births affected
Describe the presentation of biliary atresia. What signs are present on examination?
- First few weeks of life
- Janudice
- Dark urine, pale stools
- Appetite and growth distrubance
Examination:
- Janudice
- Hepatomegaly with splenomegaly
- Abnormal growth
- Cardiac murmur with cardiac abnormalities present
What investigations would you do for biliary atresia?
- LFTs - serum bile acids and aminotransferases raised but not differentiating from other causes of jaundice
- Serum bilirubin (conjugated + unconjugated) - total normal but conjugated abnormally high
- US liver and biliary tree - distension and tract abnormalities
-
Other:
- Alpha-1 antitrypsin - serum deficiency may cause cholestasis
- Sweat chloride test - CF involves biliary tract
- Percutaneous liver biopsy + intraoperative cholangioscopy
What is the management of biliary atresia?
- SURGERY - dissection of abnormalities into distinct ducts/anastomosis creation
- Antibiotic coverage and bile acid enhancers following surgery
- Nutrition and fat soluble vitamin supplementation
If surgery is unsuccessful: transplantation.
What surgery is used for biliary atresia?
Palliative surgery
Kasai hepatoportoenterostomy (loop of jejunum is anastomosed to the cut surface of the porta hepatis) - bypasses the fibrotic ducts and facilitated drainage of bile from any remaning patent ductules
80% will clear jandice if this surgery is done in <60days of life
BUT even if successful, disease progresses to cholangitis and cirrhosis with portal hypertension in moct
What are the complications of biliary atresia? What is the prognosis?
- Unsuccessful surgery
- Liver disease progression
- Cirrhosis with hepatocellular carcinoma
Prognosis: good if surgery suceeds but if fails then transplantation may be required within first 2 years of life.
What are 5 features of a congenital diaphragmatuc hernia?
5 B’s:
- B: Bochdalek (name)
- B: barrel chest appearance
- B: back / lateral (usually on the left)
- B: baby (rarely present in adulthood)
- B: bad (associated with pulmonary hypoplasia and high mortality risk)
How common is congenital diaphragmatic hernia?
Congenital diaphragmatic hernia (CDH) occurs in around 1 in 2,000 newborns.
What is the pathophysiology of CDH?
Pleuroperitoneal canal fails to close
Why is mortality of CDH so high?
Mortality is 50%
Herniated viscera may have cause lung hypoplasia causing high mortality after birth
What is the management of CDH?
Large nasogastric tube is placed and suction applied to prevent distension of the intrathoracic bowel
Surgical repair after stabilisation
What is the most common type of CDH?
Left sided herniation of bowel through the posterolateral foramen causing heart sounds to be displaced to the right side
AKA Bochdalek hernia (accounts for 85% of cases)
What is oesophageal atresia usually associated with?
Tracheo-oesophageal fistula
Describe the types of oesophageal atresia/tracheo-oesophageal fistula that can occur.
How common is oesophageal atresia? What are the risk factors? What is seen on antenatal scan?
1 in 3500 live births affected
Polyhydramnios during pregnancy
Absent stomach bubble on antenatal scan
How does oesophageal atresia present if not detected antenatally?
- Persistent drooling
- Coughing and choking when fed
- Cyanotic episodes
- Aspiration of saliva or acid secretions from stomach
What % of babies will have other congenital abnormalities with oesophageal atresia? Name these.
50% will have other congenital malformations e.g. VACTERL association
- V - vertebral
- A- anorectal
- C - cardiac
- TE - tracheo-oesophageal
- R- renal
- L- limb
What is the management if oesophageal atresia is suspected antenatally?
At birth a tube is passed and XR done to see if it reaches the stomach
Continuous suction is applied to reduce aspiration of saliva and secretions
Transfer to neonatal surgical unit for correction
Wha are the complications following surgery for oesophageal atresia/tracheo-oesophageal fistula?
- GORD
- Chronic cough
- May require oesophageal dilation in infancy or childhood
Define cleft lip.
Unilateral or bilateral defect where there is failure of fusion of the frontonasal and maxillary processes.
Define cleft palate.
Failure of fusion of the palatine processes and the nasal septum.
What is shown here?
Abdominal X-ray in duodenal atresia showing a ‘double bubble’ from distension of the stomach and duodenal cap. There is absence of air
distally
How does GFR change with age?
What are the features of Potter’s syndrome? What is the cause?
- low set ears
- beaked nose
- prominent epicathic folds and downward slant to eyes
- pulmonary hypoplasia causing respiratory failure
- limb deformities
Cause: intrauterine compression of fetus fromoligohydramnios due to lack of fetal urine from renal agenesis
What is the cause of multicystic dysplastic kidneys in neonates? What is the prognosis?
Cause: Failure of the union of the ureteric bud (forming ureter/pelvis/calyces and collecting ducts) with the nephrogenic mesenchyma. This forms non-functioning structure with large fluid filled cysts with no renal tissue and no connection with the bladder.
Prognosis: half will involute by age 2 and nephrectomy only required if hypertension develops or if the structure is large. Potter’s syndrome can develop which is fatal if the defect is bilateral.
List 3 other causes of large cystic kidneys in a neonate.
- AR polycystic kidney disease
- AD polycystic kidney disease
- Tuberous sclerosis
NB: in contrast to multicystic dysplastic kidney, there is some or normal renal function in these conditions.
What is a duplex system kidney?
Varies - can be a bifid renal pelvis or complete division with two ureters
Lower pole moiety often refluxes, whereas upper may drain ectopically into urethra or vagina or prolapse into the bladder (ureterocele) and flow obstructed.
What do these renal ultrasounds show?
Left) dilated renal pelvis from pelviureteric junction obstruction
Right) normal ultrasound of kidney for comparison
Give 2 causes of unilateral hydronephrosis and bilateral hydronephrosis.
Unilateral:
- Pelviureteric junction obstruction
- Vesicoureteric junction obstruction
Bilateral:
- Bladder neck obstruction
- Posterior urethral valves
What is the diagnosis?
Posterior urethral valves
What is the management of congenital urethral abnormalities detected antenatally?
What is a MCUG scan?
Micturating cystourethrogram - contrast introduced into bladder through urethral catheter.
Uses: visualising VUR and urethral obstruction
Disadvantages: invasive and unpleasant beyond infancy, high radiation dose, can introduce infection
What are the causes/risk factors for cryptorchidism?
Hormonal: abnormalities in the pathways/signalling of testosterone, mullerian inhibiting substance, insulin-like 3 hormone or its receptor LGR8, epidermal growth factor, and/or oestrogens.
Environmental or maternal toxins: organochlorines, environmental oestrogens, phthalate esters, and pesticides
Maternal: alcohol consumption, analgesic consumption, and smoking
Gestational diabetes and/or obesity
Genetic: up to 23% of cases have been associated with familial clustering; mutations include insulin-like factor 3 and its receptor, LGR8, and CAG/GGC repeats in androgen receptor genes.
Mechanical: problems with development of the gubernaculum or cremasteric muscle fibres, a patent processus vaginalis, or impaired intra-abdominal pressure
Neuromuscular: abnormalities of the calcitonin gene-related peptide of the genitofemoral nerve or the cremasteric nucleus
