Congenital Malformations

Question 1

Define cleft palate/lip.

Answer 1

Congenital malformation, resulting in clefts that involve the lip, hard palate and the soft palate; may be unilateral or bilateral.

Question 2

Define diaphragmatic hernia.

Answer 2

Congenital defect in the formation of the diaphragm that leads to the protrusion of abdominal contents into the thoracic cavity.

Question 3

Define tracheoesophageal fistula.

Answer 3

A tracheo-oesophageal fistula (TOF) is an abnormal communication between the oesophagus and the trachea.

Question 4

Define oesophageal atresia.

Answer 4

Congenital malformation of the oesophagus with failure of continuity of the oesophageal lumen resulting in an upper and lower oesophageal pouch.

Question 5

Define small bowel atresia.

Answer 5

Congenital malformation of the gastrointestinal tract (duodenum, jejunum and ileum) resulting in absence or complete closure of a portion of its lumen.

Question 6

Define biliary atresia.

Answer 6

Malformation of the bile ducts which causes the ducts to be abnormally narrow, blocked or absent.

Question 7

Define urinary tract anomalies.

Answer 7

Congenital structural abnormalities of the kidneys, bladder or urethra.

Question 8

Define anorectal malformations.

Answer 8

Wide spectrum of congenital disorders affecting the distal anus and rectum as well as the urinary and genital tracts.

Question 9

Define cryptorchidism.

Answer 9

Failure of normal descent of the testicle to a scrotal position.

Question 10

Explain the aetiology/risk factors for cleft palate/lip.

Answer 10

Cleft Lip: Results from failure of fusion of the frontonasal and maxillary processes.

Cleft Palate: Partial or total failure of fusion of the palatal shelves.

Risk factors: Strong genetic element, associated with 400 syndromes, link with maternal smoking.

Question 11

Explain the aetiology/risk factors for diaphragmatic hernia.

Answer 11

General: More commonly unilateral although may be bilateral. Lt > Rt. Bowel or ntra-abdominal viscera may have herniated. Common for liver (Rt) and also spleen (Lt) to be herniated. There may be associated abnormal hepatic vasculature. Associated with abnormalities of the pulmonary tree, vasculature and surfactant deficiency hypoplastic lungs).

• Posterolateral Bochdalek hernia: 90% of cases, commonly left-sided, posterolateral defect.
• Morgagni hernia: 3% of cases, commonly right-sided (90%), anteromedial defect.
• Congenital hiatus hernia: Rare, stomach herniates through the oesophageal hiatus

Question 12

Explain the aetiology/risk factors for tracheoesophageal fistula and oesophageal atresia.

Answer 12

The vast majority of patients have proximal oesophageal atresia with a distal tracheoesophageal fistula.

• VACTERL (Vertebral, anorectal, cardiac, tracheal, esophageal, renal, limb anomalies)
• CHARGE (Coloboma, heart defects, atresia choanal, retarded growth + development, genital hypoplasia + ear deformities).

Question 13

Explain the aetiology/risk factors for duodenal atresia.

Answer 13

The duodenum ends in a blind pouch either distally to the ampulla of Vater (75%) or proximally (25%). Type I (duodenal web), type II (complete obstruction with fibrous cord between proximal and distal pouches) and type III (complete gap between pouches).

Question 14

Explain the aetiology/risk factors for jejnual and ileal atresia.

Answer 14

Type I (membranous obstruction), type II (intact mesentery and fibrous cord between pouches), type III (mesenteric defect with gap between pouches), type IIIb (apple-peel deformity), type IV (multiple jejunoileal atresias).

Commonest: 30% proximal jejunum, 35% distal ileum.

Question 15

Explain the aetiology/risk factors for general small bowel atresia.

Answer 15

Exact causes unknown. Possible failure of recanalisation of the duodenum during the embryonic solid core stage or in utero mesenteric vascular accident.

Question 16

What are the associations for duodenal, jejunal and ileal atresia?

Answer 16

Associations of duodenal atresia: Polyhydramnios, Down’s syndrome malrotation, congenital cardiac abnormalities, early intrauterine intussusception.

Associations of jejunoileal atresia: Prematurity, Low birth weight, consanguineous, maternal infections.

Question 17

Explain the aetiology/risk factors for biliary atresia.

Answer 17

• Type I involves obliteration of the common duct; the proximal ducts are patent
• Type II is characterized by atresia of the hepatic duct, with cystic structures found in the porta hepatis
• Type III (>90% of patients) involves atresia of the right and left hepatic ducts to the level of the porta hepatis.

Associations: CMV infections, aflatoxin B.

Question 18

Explain the aetiology/risk factors general urinary tract anomalies.

Answer 18

Also known as CAKUT (congenital anomalies of the kidney and urinary tract), associated with severe different chromosomal loci abnormalities and PAX2 gene mutation.

Question 19

Explain the aetiology/risk factors for renal abnormalities.

Answer 19

• Multicystic dysplastic kidneys (MCDK): multiple renal cortex and medulla cysts.
• Medullary sponge kidney: congenital cystic dilation of the collecting ducts allowing calculi formation.
• Nephronophthisis: multiple cyst formation at the corticomedullary junction with progressive glomerular sclerosis.
• Unilateral renal agenesis: congenital absence of a kidney secondary to lack of induction of the metanephric blastema by the ureteral bud.
• Ectopic/horseshoe kidney: fusion of the lower poles (>90% cases) resulting in either symmetrical or asymmetrical horseshoe.

Question 20

Explain the aetiology/risk factors for non-renal urinary tract abnormalities.

Answer 20

• Pelviureteric junction (PUJ) obstruction: secondary to stenosis or atresia of the proximal ureter.
• Vesicoureteral reflux (VUR): with associated hydronephrosis.
• Non-obstructed non-refluxing primary megaureter: aperistaltic and narrowed prevesical portion of the ureter.
• Bladder outlet obstruction: secondary to posterior urethral valves (PUV); congenital lesions causing variable degrees of obstruction (may present with severe renal failure).
• Ureterocoele: presence of an intrabladder hernia or cystic ballooning at the lower end of a ureter.
• Hypospadias/epispadias: abnormal ectopic urethral opening along the ventral (hypospadias) or dorsal surface (epispadias) to variable degrees.

Question 21

Explain the aetiology/risk factors for general anorectal malformations.

Answer 21

Wide spectrum of defects. Exact aetiology unknown but close genetic association. All have absence of an anus in the normal position.

• Mild forms: Bowel outlet via fistula in the perineal region separately from the normal sphincter complex.
• Severe forms: Bowel outlet ectopically opens in the urogenital tract (males) and genital tract (females).

Question 22

Explain the aetiology/risk factors for wingspread classification anorectal malformations.

Answer 22

Traditional system.

Relationship of the pouch to the levator muscle complex: either low, intermediate and high.

Question 23

Explain the aetiology/risk factors for Krickenbeck classification anorectal malformations.

Answer 23

Recent international consensus.

• Major group: Presence of fistula (perineal, rectourethral, prostatic, bulbar, rectovesical, vestibular) or no fistula and cloaca or anal stenosis.
• Minor group: Pouch colon, rectal atresia/stenosis, rectovaginal fistula, H-fistula, others.

Question 24

Explain the aetiology/risk factors for cryptorchidism.

Answer 24

First stage (transabdominal): The fetal gubernaculum enlarges under the control of INSL3 (and MIS/AMH) and testosterone. This anchors the testicle near the inguinal region during growth of the fetal abdominal cavity.

Second stage (inguinoscrotal): Involves the migration of the gubernaculum to the scrotum with elongation of the PV within it, under androgen control.

The testicles remain retroperitoneal until 28/40.

Question 25

Summarise the epidemiology for cleft palate/lip.

Answer 25

1/1000 live births.

Question 26

Summarise the epidemiology of diaphragmatic hernia.

Answer 26

1/3000 live births. M: F = 3:2.

Question 27

Summarise the epidemiology of tracheoesophageal fistula with oesophageal atresia.

Answer 27

1/4500 live births M:F = 1.26:1

Question 28

Summarise the epidemiology of small bowel atresia.

Answer 28

Duodenal: 1/5000 Jejunoileal: 2/5000

Question 29

Summarise the epidemiology of biliary tree atresia.

Answer 29

1 per 10,000-15,000 live births

Question 30

Summarise the epidemiology of urinary tract anomalies.

Answer 30

3–6/1000

Question 31

Summarise the epidemiology of anorectal malformations.

Answer 31

1 in 5000 live births. M\>F

Question 32

Summarise the epidemiology of cryptorchidism.

Answer 32

3% of full-term male infants. 30% of premature infants.

Question 33

What are the symptoms of cleft palate/lip?

Answer 33

**At birth:** Overt clefts of the hard (and soft palate). **Postnatal:** * Feeding difficulties: suckling may be compromised by the loss of an oral seal. * Airway difficulties: prolapse of the tongue through the cleft into the nasal cavity, especially if associated with mandibular hypoplasia (Pierre Robin sequence). * Nasal reflux of liquid or food: in partial clefts of the soft palate. * Hypernasal speech or nasal emission - may be detected later, especially in submucosal clefts.

Question 34

What are the symptoms of diaphragmatic hernia?

Answer 34

There may be a history of maternal polyhydramnios. Difficulty in breathing. Recurrent chest infection.

Question 35

What are the symptoms of oeseophageal atresia?

Answer 35

A history of polyhydramnios prenatally. Excess mucus, coughing choking or cyanosis with the first feed.

Question 36

What are the symptoms of small bowel atresia?

Answer 36

Vomiting and abdominal distension. Vomiting is usually bile-stained in jejunal or ileal atresia. Can be non-bilious in some forms of duodenal atresia.

Question 37

What are the symptoms of biliary tree atresia?

Answer 37

Neonatal jaundice. Irritability. Poor growth. Pale stools and dark urine. Swollen abdomen.

Question 38

What are the symptoms of urinary tract anomalies?

Answer 38

Antenatal: Oligohydramnios, decreased foetal urine output. Postnatal: Irritability.

Question 39

What are the symptoms of anorectal malformations and cryptorchidism?

Answer 39

**Anorectal malformations:** No specific symptoms. **Cryptorchidism:** Asymptomatic, picked up during examination. May have associated inguinal hernia.

Question 40

What are the signs of cleft palate/lip?

Answer 40

Should be able to see and palpate a cleft. A posterior cleft may also be present.

Question 41

What are the signs of a diaphragmatic hernia?

Answer 41

Cyanosis, respiratory distress, shift of cardiac sounds onto the right side of chest if hernia is big.

Question 42

What are the signs of tracheoesophageal fistula with oesophageal atresia?

Answer 42

Abdominal distension in TOF, “scaphoid” abdomen in OA if it is present alone. Other syndromic signs – murmurs etc.

Question 43

What are the signs of small bowel atresia?

Answer 43

Abdominal distension

Question 44

What are the signs of biliary tree atresia?

Answer 44

Prolonged jaundice, abdominal distension, acholic stool, hepatomegaly, ascites and bruising.

Question 45

What are the signs of urinary tract anomalies?

Answer 45

Decreased foetal urine output, intra-abdominal masses, haematuria, renal calculi, renal failure, hypertension and hepatosplenomegaly.

Question 46

What are the signs of anorectal malformations?

Answer 46

General: Clinical examination. Associated anomalies. Specific (low lesions): Prominent midline skin bridge (‘bucket-handle’), subepithelial midline raphe fistula, rectovestibular fistula, anal membrane. A flat perineum (absence of midline gluteal fold and anal dimple) may indicate absence of perineum muscle and therefore a high ARM.

Question 47

What are the signs of cryptorchidism?

Answer 47

The most common location of the cryptorchid testis is in the inguinal canal. The testis may also be in the prescrotal and abdominal regions.

Question 48

What are appropriate investigations for cleft palate/lip?

Answer 48

Can be diagnosed by USS. Can also be detected during the new-born baby check.

Question 49

What are appropriate investigations for a diaphragmatic hernia?

Answer 49

Chromosomal studies. CXR, Cardiac ECHO, Renal USS.

Question 50

What are appropriate investigations for tracheoesophageal fistula with oesophageal atresia?

Answer 50

CXR with coiled NGT in upper pouch, distal bowel gas indicates presence of distal TOF. ECHO for cardiac anomalies and Renal USS.

Question 51

What are appropriate investigations for small bowel atresia?

Answer 51

AXR will show the “double bubble” sign, absent or reduced gas past the obstructions. In jejunoileal atresia the AXR will show dilated loops of bowel.

Question 52

What are appropriate investigations for biliary atresia?

Answer 52

Bloods: FBCs, LFTs, Bilirubin (Total + conjugated), INR, plasma or serum amino acids. Urinary (organic acids, succinyl acetone, bile acids, lactate to pyruvate ratio). Imaging: Ultrasound, CXR, cholangiogram, Tc 99m scan. Liver biopsy.

Question 53

What are appropriate investigations for urinary tract anomalies?

Answer 53

Ultrasound: Non-invasive, operator dependent, diagnostic in majority of congenital malformations. Intravenous urogram (IVU): Visualization of majority of anomalies including VUR/PUV that are not visualised that well by USS. Nuclear renal imaging: DMSA and MAG3 for assessment of kidney function and perfusion. May overestimate function in an obstructed system, however.

Question 54

What are appropriate investigations for anorectal malformations?

Answer 54

**General:** Screening for associated anomalies: ECHO, CXR (NGT position/heart), RUSS, serum karotype, USS for hydrometrocolpos/spinal anomalies, sacral XR, MRI, urinalysis. **Specific:** Prone cross-table lateral XR with the pelvis elevated and marker on the perineum (air column to marker 1 cm¼colostomy), high-pressure distal colostography (distal stomal contrast to delineate distal rectum and urinary connection).

Question 55

What are appropriate investigations for cryptorchidism?

Answer 55

Clinical diagnosis. USS abdomen to aid location of the testis. In bilateral absence conduct hormonal tests (B-HCG) and chromosomal mapping.

Question 56

What is the management for cleft palate/lip?

Answer 56

**Multidisciplinary approach:** Plastic and ENT surgeons, dentists, speech therapist, audiologists, nutritionists, specialist children’s nurses and social workers. **Advice:** Slower feeding, positioning the nipple along the non-cleft side and towards the back of the mouth in breastfeeding, use of cleft palate feeders, semi-upright positioning, and regular monitoring for signs of inadequate feeding or dehydration. **Surgical correction:** Should occur \<1 year to facilitate normal speech and language development.

Question 57

What is the management for a diaphragmatic hernia?

Answer 57

**Medical:** NGT to decompress the bowel. Respiratory support via endotracheal tube and mechanical ventilation. Surfactant administration, Nitric oxide therapy or ECMO in the most severe cyanotic infants. **Surgery:** After optimizing the neonate, surgery is via thoracoscopic or laparoscopic transabdominal approaches. Reduction of the hernia and suturing the defect.

Question 58

What is the management for tracheoesophageal fistula with oesophageal atresia?

Answer 58

**Immediate:** Positioning of the infant to avoid regurgitation and aspiration of pneumonia. Suction and irrigation applied to the upper pouch using replogle tube. Keep Nil by mouth. **Surgical:** * TOF ligation if identified early. * PEG and ligation of TOF. Can later replace the oesophagus with a gastric tube and bowel thoracic transposition.

Question 59

What is the management for small bowel atresia?

Answer 59

**General:** ABCDE approach, stabilize the neonate with NGT decompression. NBM. Manage other associated abnormalities. **Surgical:** Primary anastomosis or Ladd procedure if malrotation is present. Need to examine the entire bowel to exclude other multiple atretic segments.

Question 60

What is the management for biliary atresia?

Answer 60

Hepatoportoenterostomy Liver transplant Ongoing: Antibiotic prophylaxis, Ursodeoxycholic acid, nutritional vitamin supplementation.

Question 61

What is the management for urinary tract anomalies?

Answer 61

**General:** Antenatal counselling with screening for associated anomalies or karyotyping as appropriate. **Medical:** Symptom control (hypertension), calcium supplements, phosphate binders, 1,25-dihydroxyvitamin D3 for PTH suppression (renal osteodystrophy), antibiotics (UTI/ prophylaxis), dialysis (renal failure). **Surgical:** Treatment of cause, e.g. nephrectomy (MCDK/non-functioning kidney), hypospadias correction (e.g. Snodgrass procedure), open/laparoscopic pyeloplasty (PUJ obstruction), PUV or ureterocoele puncturing (endoscopic procedures) nephrostomy placement (obstructed system), suprapubic catheter placement.

Question 62

What is the management for anorectal malformations?

Answer 62

**Medical (neonatal):** Resuscitation as appropriate. Associated anomalies screening, NGT, NBM, antibiotics, transfer to paediatric surgical centre. Often have 24 hours to stabilize as low obstruction. Clinically observation for passage of meconium. **Surgical (neonatal):** Ascertain provisional diagnosis of ARM level with surgical planning. **Severe:** Primary diverting colostomy. Low: cutback anoplasty/limited PSARP. Large rectovestibular fistulas may be dilated. **Surgical (definite):** Posterior sagittal anorectoplasty (PSARP) allows excellent visualisation. Colostomy closed separately. Laparoscopic-assisted approach also possible with mobilisation of the rectal pouch/ligation of fistula and delivery of the pouch to the perineum through a minimal posterior incision. **Postsurgical incontinence:** Effective bowel management programme including enemas, laxatives and dietary manipulations.

Question 63

What is the management for cryptorchidism?

Answer 63

**Surgery:** Patent processus vaginalis ligation if required. Orchidopexy or orchidectomy if testicle is abnormal.

Question 64

What are the complications associated with cleft palate/lip?

Answer 64

Susceptibility to colds, hearing loss, speech defects, dental problems and otitis media

Question 65

What are the complications associated with diaphragmatic hernias?

Answer 65

Pulmonary hypoplasia, intestinal malrotation (40%), gastric and mid-gut volvulus, gastric or other gastrointestinal perforations, gastric volvulus and bilateral renal hypertrophy.

Question 66

What are the complications associated with tracheoesophageal fistula with oesophageal atresia?

Answer 66

Surgical complications (GORD, oesophageal stricture at site of anastomosis and recurrence). Tracheomalacia, failure to thrive and chest infections.

Question 67

What are the complications associated with small bowel atresia?

Answer 67

Pulmonary aspiration, anastomotic complications (stenosis/leak), proximal bowel may have abnormal peristalsis so there may be a prolonged postoperative course of parenteral nutrition.

Question 68

What are the complications associated with biliary atresia?

Answer 68

Kernicterus, growth failure, portal hypertension, GI bleed, ascites.

Question 69

What are the complications associated with urinary tract abnormalities?

Answer 69

Hypertension, renal osteodystrophy, urinary tract infections and calculi

Question 70

What are the complications associated with anorectal malformations?

Answer 70

Most common functional disorder post-surgery is constipation. Possible urinary and faecal incontinence.

Question 71

What are the complications associated with cryptorchidism?

Answer 71

Infertility due spermatogenesis defect, increased risk of seminoma.

Question 72

What is the prognosis of cleft palate/lip?

Answer 72

Good prognosis with repair. Large defects may result in lifelong impaired speech.

Question 73

What is the prognosis of diaphragmatic hernias?

Answer 73

Reported mortality is 25–60%

Question 74

What is the prognosis of tracheoesophageal fistula and oesophageal atresia?

Answer 74

Very good prognosis with early surgical intervention. Patients usually if they have associated major cardiac abnormalities or have a very low birth weight.

Question 75

What is the prognosis of small bowel atresia?

Answer 75

Mortality directly related to the severity of the associated anomalies and to the degree of prematurity.

Question 76

What is the prognosis of biliary atresia?

Answer 76

70% of children will ultimately require liver transplantation.

Question 77

What is the prognosis of urinary tract anomalies?

Answer 77

Most renal anomalies may lead to end-stage renal failure and its associated complications. Prognosis is good with non-renal anomalies if adequately treated.

Question 78

What is the prognosis of anorectal malformations?

Answer 78

Generally good. Low ARM has fewer complications than high.

Question 79

What is the prognosis of cryptorchidism?

Answer 79

Excellent with surgical intervention.