Hernia

Question 1

Define hernia

Answer 1

The protrusion of a viscus/organ through a defect of the wall containing cavity into an abnormal position

Question 2

Describe how embryology can contribute to a hernia

Answer 2

Testicular development is determined by the y chromosome and it must produce testosterone to descend
1. The testis, guided by the mesenchymal gubernaculum, migrates down into the inguinal canal
2. The structures found in the scrotum (testis, vas, blood vessels) pass through the abdominal wall and pick up layers
3. These layers make up the coverings of the spermatic cord
4. A remnant of the peritoneal invagination (Processus vaginalis) may remain patent → fluid or abdominal contents can pass into it → hydrocoele or hernia

Question 3

Explain how an umbilical hernia may arise

Answer 3

The umbilical ring allows passage of vessels through the abdominal wall muscles between mother and foetus
After birth and disintegration of the cord, the ring remains, with spontaneous closure typically by 5yo (growth of abdominal muscles and fusion of peritoneal and fascial layers)
Failure or delay in this process leads to the formation of an umbilical hernia

Question 4

What is incarceration and strangulation of a hernia

Answer 4

Incarceration = abdominal viscera or omentum becomes stuck within the hernia (irreducible)

Strangulation = viscera becomes stuck in the hernia with compromise to their blood supply → ischaemia or necrosis

Question 5

What are the types of hernia

Answer 5

Inguinal
Umbilical
Paraumbilical
Femoral
Epigastric
Congenital diaphragmatic
Exomphalos/omphalocoele
Gastroschisis

Question 6

What is the cause of inguinal hernias, where is it most likely to be and what is the risk difference between age groups

Answer 6

Persistently patient processus vaginalis
Hernia emerges from the deep inguinal ring through the inguinal canal (usually INDIRECT)
More likely to be right sided (as left PV obliterates before the right)
The risk of incarceration is higher in infants than older children

Question 7

Which hernia are babies more likely to get if born premature

Answer 7

Direct inguinal hernia as they weaker tissue that is more friable

Question 8

What are the risk factors for an inguinal hernias

Answer 8

Preterm infants (esp. LBW)
Boys (as ovaries don’t leave the abdominal cavity)
Infants with chronic lung disease
Conditions causing abdominal fluid or increased abdominal pressure e.g. cystic fibrosis
CT disorder

Question 9

What are the symptoms and signs of an inguinal hernia

Answer 9

Lump in the groin
- May extend into the scrotum or labia majora
- Usually asymptomatic, intermittent, visible on sraining
- Reducible unless incarcerated (tender, red, firm)
Non-transluminable (but may be in young patients)
Abdominal pain
Irritability
Nausea and vomiting
Swelling in the scrotum visible upon straining or crying

Question 10

What is the management for an inguinal hernia

Answer 10

Surgery (herniotomy)
- First few months of life - urgent hernia repair (higher risk of strangulation)
- >1yo: elective surgery

Neonates: If reducible → elective herniorrhaphy repair
- <6w: correct within 2 days
- <6m: correct within 2 weeks
- <6yo: correct within 2 months

Most cases are performed as day cases, neonates and premature infants are kept in hospital overnight as there is a recognised increased risk of post operative apnoea.

Question 11

What are the complications and prognosis of inguinal hernias

Answer 11

Incarceration
Herniotomy- recurrence, damage to vas deferens, testicular vessels, ascending ipsilateral testicle secondary to scarring
Excellent prognosis with surgical repair

Question 12

What are the risk factors for an umbilical hernia

Answer 12

Prematurity
Afro-Caribbean
Down’s syndrome
Mucopolysaccharide storage devices
Low birth weight
Ehlers-Danlos syndrome
Hypothyroidism

Question 13

What are the symptoms and signs of an umbilical hernia

Answer 13

Hernia:
- Painless
- Reducible
- More prominent on straining or crying

Question 14

What is the management for an umbilical hernia

Answer 14

Observation: Typically resolves by 4-5 years of age (most by 12 months)

If it persists beyond 4-5yo → elective outpatient surgical repair

Large or symptomatic hernia (>1.5cm) → intermittent symptoms of incarceration or recurring pain → elective repair at 2-3yo

Incarceration → manually reduce with pressure + surgical repair within 24h (may require emergency op if it cannot be reduced)
+ safety net

Question 15

What should be advised on safety netting for a hernia

Answer 15

Strangulation
Vomiting, pain
Unable to push the hernia in
Complete constipation, unable to pass flatus

Question 16

Describe paraumbilical hernias

Answer 16

Due to defects in the linea alba that are in close proximity to the umbilicus
The edges of a paraumbilical hernia are more clearly defined than those of an umbilical hernia
They are LESS LIKELY to resolve spontaneously than an umbilical hernia

Question 17

Describe femoral hernias in children

Answer 17

Difficult to differentiate from indirect inguinal hernias
Located below inguinal canal (through femoral canal)
Differentiation often made during operation
S/S same as for indirect inguinal hernia

Question 18

Describe epigastric hernias

Answer 18

Occur in the midline, anywhere from xiphoid process to the umbilicus
Most contain preperitoneal fat
10% have multiple defects - multiple lumps in midline

Question 19

What are the signs and symptoms of an epigastric hernia

Answer 19

Abdominal mass (Commonly enlarges)
Abdominal pain/tenderness
Pain and irritation of the skin (due to hernias rubbing against clothes)

Question 20

What is the management for an epigastric hernia

Answer 20

Refer to hospital for further assessment
Surgical repair

Question 21

Describe congenital diaphragmatic hernias

Answer 21

1 in 2,000
Herniation of the abdominal viscera into the chest cavity due to incomplete formation of the diaphragm → pulmonary hypoplasia + hypertension → resp. distress
Usually represents a failure of the pleuroperitoneal canal to close completely
most common type of CDH is a left-sided posterolateral Bochdalek hernia which accounts for around 85% of cases.

Question 22

What are the signs and symptoms of a congenital diaphragmatic hernia

Answer 22

Resp. distress (Dyspnoea, Tachypnoea)
Failure to respond to resuscitation
Barrel-shaped chest
Scaphoid-appearing/ concave abdomen (because of loss of abdominal contents into the chest)
Cardio-Resp exam:
- Reduced breath sounds
- Absence of breath sounds on the ipsilateral side
- Displaced heart sounds and apex beat if left sided herniation

Question 23

What is the management for congenital diaphragmatic hernia

Answer 23

1. intubate and ventilate (prevent swallowing of air → expansion of bowel within the chest
2. Decompress bowel using NG tube and suction
3. Place an umbilical artery line for frequent monitoring
4. Refer for surgery to close the diaphragmatic defect and reduce the viscera into the abdominal cavity

Note: avoid bag-and-mask ventilation as it may cause expansion of the bowel within the chest

Question 24

What are the complications of congenital diaphragmatic hernia

Answer 24

Persistent pulmonary hypertension of the newborn
Chronic respiratory disease, pulmonary hypoplasia (compression by herniated viscera)
Recurrent hernia problems
Spinal/ chest wall abnormalities
GI difficulties- volvulus, acute bowel obstruction which may lead to perforation of herniated loop
Neurological sequelae

Question 25

What is the prognosis for congenital diaphragmatic hernia

Answer 25

50% of newborns survive despite modern medical intervention
depends on (1) liver position, (2) lung-to-head ratio
Improved survival rates with better preoperative management to avoid lung injury
If the lungs are hypoplastic, mortality is high

Question 26

Describe exomphalos/omphalocoele and its risk factors

Answer 26

Bowel protruding out of the body with a peritoneal covering (umbilicus attached)

RF: Chromosomal abnormalities in 15% of cases (Trisomy 13 (Patau’s), 18 (Edward’s), 21 (Down’s); Turner’s)

Question 27

What is gastroschisis

Answer 27

paraumbilical abdominal wall defect → abdominal contents outside body, without peritoneal covering

Question 28

What are the signs of hernia incarceration

Answer 28

Unsettled pain
Vomiting
Tenderness
Unable to pass stool (constipation)
Poor feeding
Non-reducible firm inguinal scrotal mass
Erythema
Oedema
Abdominal distension

Question 29

What are the signs of strangulation

Answer 29

Expansile cough impulse
Pain
Fever
Increase in the size of a hernia or erythema of the overlying skin
Peritonitic features such as guarding and localised tenderness
Bowel obstruction e.g. distension, nausea, vomiting
Bowel ischemia e.g. bloody stools

Question 30

What is the management for hernia incarceration/strangulation

Answer 30

Urgent admission and assessment to the surgery team
→ emergency manual reduction of hernia contents under sedation (IV morphine) with repair after 48 hours to allow oedema to settle