6.2: Hernias, Bowel Obstruction and Constipation

Question 1

What is a hiatus hernia? Describe the two types

Answer 1

Hernia through the diaphragm;
1. Sliding: type of inguinal hernia where a retroperitoneal structure “slides” down the posterior abdominal wall and herniates directly or indirectly into the inguinal canal, dragging overlying peritoneum with it

2. Rolling: part of the fundus may pass into the chest alongside the esophagus

Question 2

What is the most common region where hernias occur and which two types of hernias occur commonly within this region? How might you differentiate between them?

Answer 2

Groin hernia

1. 85% inguinal hernia
2. 15% femoral hernia

Inguinal hernias occur above the inguinal ligament, whereas femoral hernias protrude onto the upper thigh below the inguinal ligament.

Question 3

What are the seven types of ventral hernias?

Answer 3

1. Para-umbilical
2. Epigastric
3. Spighelian
4. Incisional
5. Para-stromal
6. Umbilical
7. Port site

Question 4

What is the most common form of a hernia? In which gender are they more common and why?

Answer 4

Indirect inguinal hernia: more common in males, as the testicular apparatus is much more fragile than the round ligament of the uterus

Question 5

List seven major causes if hernias

WWDTPCS

Answer 5

1. Weakness due to structures leaving/entering the abdomen; spermatic cord, femoral vessels, esophagus, obturator nerve
   * can be due to ageing; degenerative weakness
2. Design weakness: in posterior wall of inguinal canal or lumbar triangle
3. Developmental failures; umbilicus (adult version para umbilical hernia), processes vaginalis
4. Trauma
5. Pregnancy: hormones make ligaments slack for birth and increases the intra-abdominal pressure (ascites will also do this)
6. Collagen disease (FH)
7. Smoking

Question 6

What is significant about the mid-point in the inguinal ligament

Answer 6

Where femoral artery is found

*halfway between ASIS and pubic symphysis

Question 7

What is the myo-pectineal orifice (MPO) and what type of hernia is it responsible for?

Answer 7

Weal area down in the groin and is what direct hernias come through

Question 8

How common are femoral hernias and which gender are they more common in? What are they more likely to become incarcerated than an inguinal hernia and what is one other potential complication that can occur?

Answer 8

Uncommon due to the inflexibility of the lacunar ligament, more common in females. More likely to be incarcerated as the femoral canal has a ‘tighter entrance’ and intestine is likely to get stuck.

Femoral hernias are also likely to strangulate (prevent circulation) due to the lacunar ligament and can cause bowel obstruction

Question 9

How would you examine a patient with a suspected groin hernia?

Answer 9

Examine standing them up, ask patient to cough but if nothing can be observed must invaginate the scrotum with a finger and stick it up along the inguinal canal, hoping to feel the hernia coming out through the deep inguinal ring while the patient coughs.

Question 10

What are three generic and six specific causes of lumps?

Answer 10

Generic:

1. Lymph node
2. Lipoma
3. Sebaceous cyst

Specific: inguinal or femoral hernia, sapheno varix (small venous aneurysm), hydrocele of the cord (hydrocele of the canal nuke in females), ectopic testis (can be found anywhere in the line of descent), psoas abscess (abscess of TB of the spine which drains down the iliopsoas muscle and appears in the groin)

Question 11

What are the five ways hernias can develop?

Answer 11

1. Occult: can’t see
2. Reducible:
3. Irreducible: (incarcerated) can’t push it back in
4. Strangulated: cuts off blood supply (venous cut off first as it’s lower pressure and can have venous gangrene, but arterial continues to pour in)
   5: Infarcted

Question 12

Which hernia can give you strangulation without obstruction?

Answer 12

Richter’s Hernia: anti-mesenteric wall of intestine protrudes through a defect in the abdominal wall - causes strangulation and infarction of one of the bowel walls

Question 13

What is a sliding hernia? Name three organs where this may occur

Answer 13

Possibility for a sigmoid, caecum or appendix sliding hernia

Question 14

What is a Pantaloon hernia?

Answer 14

Combined direct and indirect hernia (straddles the inferior epigastric vessels)

Question 15

Why are umbilical hernias a common congenital disorder and how would you treat one?

Answer 15

In normal embryological development the midgut herniated out of the umbilical ring and should return a few weeks later, BUT if it doesn’t this provides a defect in the abdominal wall that abdominal contents can herniate out of.

They often close themselves spontaneously but operate of there is danger of strangulation or if they haven’t closed by age 4-4.5

Question 16

What is a para-umbilical hernia and in which population group is it most common?

Answer 16

Weakening of tissues around the umbilicus or in the linea alba around the umbilicus. Common in obese patients and multiparous women

Question 17

Where do spigelian hernias occur?

Answer 17

In the junction between linea semilunaris and the arcuate line

Question 18

What are five patient factors, 2 wound factors and 2 surgical factors that predispose someone to an incisional hernia? How common are they and what is a potential complication?

Answer 18

5% occur after all abdominal operations, 50% occur within 5 years of an operation

Patient factors: obesity, chemotherapy/cancer, immunosuppressive, malnutrition, chronic cough

Wound factors; poor tissues and wound infection (if collagen fibres don’t heal properly post surgery can get an infection)

Surgical factors: suturing material (how strong) and technique

Can get bowel obstruction due to adhesions in the bowel (but not strangulation)

Question 19

What is divarication of recti and which population group is the most predisposed to it?

Answer 19

A bulge over the linea alba due to weakened muscles BUT it’s not a hernia (repaired for purely cosmetic reasons), common in obese patients and pregnancy

Question 20

What is a para-stomal hernia and which type of surgical operation is likely to cause one? What are two potential complications?

Answer 20

Commonly caused by a colostomy, introducing a stoma weakens the surrounding abdominal wall and a part of bowel can come into the stoma.

Can cause obstruction and strangulation, and also leakage out the sides of the bag due to the increased pressure

Question 21

What are the two types of rare external hernias and how are they caused?

Answer 21

1. Lumbar hernia: A defect in the posterolateral abdominal wall. Doesn’t tend to strangulate and can be left alone
2. Obturator hernia; obturator nerve goes through obturator foramen which can weaken the area leading to a hernia. Can cause leg pain

Question 22

Why should we operate on hernias?
*4 reasons

Which type of hernia is always referred to for immediate surgery?

Answer 22

1. Painful or aching symptoms
2. Cosmetic
3. Bowel obstruction
4. Risk of strangulation (1%) but if it occurs mortality is >15%

Femoral hernia always operated on

Question 23

How is an inguinal hernia treated? What are 3 general principles of hernia repair?

Answer 23

1. Operate: open, laparoscopic (GA); can give a TAPP (trans abdominal preperineal or TEPP (total extraperitoneal)
2. Non-operative; Truss (metal band that pushes the hernia in), no treatment

General principles

1. Don’t put tension (i/e no strenuous post-surgical physical work)
2. Use specialized mesh; generates scar tissue
3. Laparoscopic reinforcement

Question 24

When would you give local vs general anaesthetics in surgical hernia repair?

Answer 24

May give local anaesthetic to reduce risk of comorbidities, if patient is not very fit and hernia not very big giving a general anaesthetic may be too dangerous

Question 25

Why might you have groin pain without a hernia?

*Include the 3 nerves in the inguinal region

Answer 25

Due to nerve entrapment; i.e as scar tissue heals it shrinks and can pulls on nerves

Three nerves in the inguinal region; ilioinguinal nerve - medial thigh, genital femoral nerve, iliohypogastric - above groin

1. Post-operative hernia repair
2. Sportsman’s groin; can also be due to tears

Question 26

What makes the lateral and medial borders of the deep inguinal ring?

Answer 26

Superior/Lateral: conjoint tendon
Medial: inferior epigastric
Inferior: inguinal ligament

Question 27

What are the major two potential clinical consequences of an incarcerated hernia?

Answer 27

1. Obstruction;
   A. Vomiting if it occurs in the small bowel
   B. Bowel perforation
   C. Massive electrolyte imbalance
2. Strangulation

Question 28

Define constipation and provide 6 causes

Answer 28

Infrequent or difficult evacuation of feces

Likely to be a multifactorial cause, causes include:

1. Obstruction
2. Painful anal conditions; haemorrhoids, anal fissure
3. Adynamic bowel: non propulsion in the bowel that causes secondary constipation (may be a result of hirschprung’s disease, spinal cord injuries, etc)
4. Drugs
5. Habit and diet; low fibre, dyschezia (rectal stasis due to power bowel habit), dehydration
6. Metabolic imbalance; hypothyroidism, hypokalemia, hypercalcemia, lead poisoning

Question 29

Why might you experience diarrhea when constipated? What are two other symptoms?

Answer 29

Diarrhea can occur as a result of overflow (fecal fluid escapes past the stuck mass of impacted feces). Likely to also experience anorexia and vague abdominal discomfort.

Question 30

How is constipation managed? Which population groups should have special considerations when being treated for constipation?

Answer 30

1. Treat any underlying cause
2. Symptomatic relief; mobilize patient, fibre, hydration, laxatives (which one is decided based on symptoms, patient choice, side effects and cost)

If there is fecal impaction can use enema (liquid or gas injected into rectum to expel contents)

*special consideration for children and pregnant women

Question 31

How common is constipation in children and how is childhood constipation treated?

Answer 31

1/3 children

Treated with a behavioural approach (many fear opening bowels and will ignore urge to defecate) alongside a monitored pharmacological intervention.

Question 32

What are six causes of neonatal constipation?

Answer 32

1. Intestinal atresia; absence of normal bodily passage (usually congenital)
2. Intestinal stenosis; narrowing of intestinal passage
3. Hirschprung’s disease: developmental failure of parasympathetic plexuses of Auerbach’s and Meissner in the gut
4. Milk Bolus Obstruction
5. Meconium ileus: thicker and stickier meconium in the intestine creating a blockage, 10% have CF
6. Hypothyroidism

Question 33

What are seven causes of constipation in infancy and older children

Answer 33

1. Hypothyroidism
2. Functional (disorder) or idiopathic
3. Encopresis: voluntary or involuntary defecation (usually with emotional disturbance or psychiatric disorder)
4. Anal fissure
5. Severe vomiting
6. Polyuria - causing dehydration (consider diabetes)
7. Neglect; inadequate food/fluid intake