Surgery

Question 1

What is the pyloric sphincter?

Answer 1

It is a ring of smooth muscle that forms the canal between the stomach and the duodenum.

Question 2

What is pyloric stenosis?

Answer 2

Hypertrophy (thickening) of the pylorus which prevents food traveling from the stomach to the duodenum as normal.
After feeding, there is increased peristalsis in the stomach as it tries to push food into the duodenum. Eventually this becomes so powerful that it ejects the food into the oesophagus and out of the mouth as projectile vomiting.

Question 3

What are the features of pyloric stenosis?

Answer 3

• presents in first few weeks of life
• hungry baby
• thinness
• pallor
• failing to thrive

Question 4

What may be seen on abdominal examination of pyloric stenosis?

Answer 4

• firm, round mass felt in the upper abdomen (‘feels like a large olive’) caused by hypertrophic muscle of the pylorus

Question 5

What can be seen on a blood gas for pyloric stenosis?

Answer 5

Hypochloric metabolic alkalosis

- due to baby vomiting HCl from the stomach

Question 6

How is pyloric stenosis diagnosed?

Answer 6

Abdominal USS - visualise thickened pylorus

Question 7

How is pyloric stenosis managed?

Answer 7

Laparoscopic pyloromyotomy (Ramstedt’s)

• incision in SM of pylorus to widen the canal to allow food to pass from the stomach to the duodenum
• excellent prognosis

Question 8

What is Hirschsprung’s disease?

Answer 8

A congenital condition where nerve cells of the myenteric plexus (which forms the enteric nervous system) are absent in the distal bowel and rectum.

Question 9

What is the myenteric nerve plexus responsible for?

Answer 9

It runs all the way along the bowel in the bowel wall and is a complex web of neurones, ganglion cells, receptors, synpases and neurotransmitters.

It stimulated peristalsis of the large bowel; without it, the bowel loses its motility and is unable to pass food along its length.

Question 10

What is the pathophysiology in Hirschsprung’s disease?

Answer 10

During foetal development, parasympathetic ganglion cells start higher in the GI tract and gradually migrate to the distal colon and rectum.

In Hischsprung’s, these parasympathetic ganglion cells do not travel all the way down the colon so a section of colon at the end is left without them.

The aganglionic section does not relax so becomes constricted leading to a loss of movement of feaces and obstruction in the bowel.

Proximal to the aganglionic part becomes distended and full.

Question 11

What risk factors exist for Hirschsprung’s disease?

Answer 11

• genes on various chromosomes have a modifying effect to increase risk
• family history

Question 12

What other syndromes is Hirschsprung’s disease associated with?

Answer 12

• Down’s syndrome
• Neurofibromatosis
• Waardenburg syndrome
• multiple endocrine neoplasia type II

Question 13

How does Hirschsprung’s disease present?

Answer 13

• acute intestinal obstruction shortly after birth
• delay in passing meconium (>24 hours)
• chronic constipation since birth
• abdominal pain and distension
• vomiting
• poor weight gain
• failure to thrive

Question 14

What is inflammation and obstruction of the intestine in those with Hirschprung’s disease called?

Answer 14

Hirschsprung-associated enterocolitis (HAEC)

Occurs in 20% neonates

Question 15

How is Hirschsprung’s disease managed?

Answer 15

• abdominal x-ray (intestinal obstruction, features of HAEC)
• rectal biopsy (absence of ganglionic cells)
• fluid resuscitation and management of intestinal obstruction (in unwell children/enterocolitis)
• IV abx (HAEC)
• NG tube

Definitive management:
- surgical removal of aganglionic bowel (may have long term disturbance in bowel function, some incontinence)

Question 16

What is biliary atresia?

Answer 16

A congenital condition where a section of the bile duct is either narrowed or absent resulting in cholestasis where the bile cannot be transported from the liver to the bowel.

Question 17

How does biliary atresia present?

Answer 17

• shortly after birth

- significant jaundice (may be persistent lasting >14 days in term babies, >21 days in preterm)

Question 18

Why does biliary atresia cause jaundice?

Answer 18

Bile cannot be excreted due to the narrowing of absence of a section of the bile duct. Conjugated bilirubin is excreted in the bile and so biliary atresia prevents the excretion of conjugated bilirubin.

High levels of conjugated bilirubin leads to significant jaundice.

Question 19

What initial investigation is used for possible biliary atresia?

Answer 19

Conjugated and unconjugated bilirubin.

High proportion of conjugated bilirubin suggests the liver is processing the bilirubin for excretion by conjugating it but it is not able to excrete it because it cannot flow through the biliary duct into the bowel.

Question 20

What is the management for biliary atresia?

Answer 20

Surgery - Kasai portoenterostomy (attaches a section of small intestine to the opening of the liver where the bile duct normally attaches = clears the jaundice and prolongs survival)

Liver transplant - often required to resolve the condition

Question 21

What is appendicitis?

Answer 21

Inflammation of the appendix.

The appendix is attached to the caecum and becomes inflamed due to infection trapped within it by obstruction at the point where the appendix meets the bowel.

Inflammation can quickly proceed to gangrene and ruptutre.

Question 22

What happens if the appendix ruptures?

Answer 22

Releases faecal content and infective material into the abdomen leading to peritonitis.

Question 23

What is the peak age of incidence of appendicitis?

Answer 23

10-20 years

Question 24

How does appendicitis present?

Answer 24

• abdominal pain (central moving to RIF over time and eventually localised to RIF)
• tenderness on palpation of the McBurney’s point
• loss of appetitie
• N&V
• Rovsing’s sign (palpation of LIF causing pain in RIF)
• guarding on abdominal palpation
• rebound tenderness
• percussion tenderness

Question 25

Which symptoms suggest peritonitis caused by a ruptured appendix?

Answer 25

Rebound tenderness

Percussion tenderness

Question 26

How is appendicitis diagnosed?

Answer 26

• clinical presentation
• raised inflammatory markers
• CT scan can confirm diagnosis
• USS in females to exclude ovarian/gynae pathology

Question 27

Give differential diagnoses for appendicitis?

Answer 27

1) Ectopic pregnancy - serum or urine bHCG essential in adolescent girls
2) Ovarian cysts - rupture/torsion
3) Meckel’s diverticulum - usually asymptomatic but can bleed, become inflamed, cause volulus or intussusception
4) Mesenteric adenitis - inflamed abdominal lymph nodes; often associated with tonsilitis or URTI
5) Appendix mass - omentum surrounds and sticks to the inflamed appendix forming a mass in RIF

Question 28

How is appendicitis managed?

Answer 28

• emergency admission to hospital under surgical team

- laparoscopic appendicectomy (preferred over laparotomy as fewer risks and faster recovery)

Question 29

What are complications of appendicectomy?

Answer 29

• bleeding, infection, pain, scars
• damage to bowel, bladder, other organs
• removal of a normal appendix
• anaesthetic risks
• VTE (DVT/PE)