Inguinal canal and hernias

Question 1

What is the inguinal canal?

Answer 1

• Canal between peritoneal cavity and abdominal wall.

Question 2

What are the limits of the inguinal canal?

Answer 2

1. Floor:
   - The medial half of inguinal ligament forms floor of inguinal canal.
2. Anterior wall:
   - External oblique aponeurosis.
   - Reinforced laterally by internal oblique.
3. Roof:
   - Overarching fibres of transversus abdominis and internal oblique.
4. Posterior wall:
   - Transversalis fascia.
   - Reinforced medially by conjoint tendon.

Question 3

How many rings are there in the inguinal canal?

Answer 3

• Two:
  1. Deep ring.
  2. Superficial ring.
• They help facilitates gonadal descent via inguinal canal.

Question 4

Where is the deep ring located?

Answer 4

• Defect in transversalis fascia.
• 1-2 cm superior to mid point of inguinal ligament.

Question 5

Where is the superficial ring located?

Answer 5

• Defect in external oblique aponeurosis.
• Oblique triangle with base at pubic tubercle, apex a little lateral

Question 6

What are the layers of the spermatic cord?

Answer 6

• 3 layers:
  1. Internal spermatic fascia (transversalis fascia)
  2. Cremasteric layer (internal oblique)
  3. External spermatic fascia (external oblique)

Question 7

What are the 3 arteries supplying that are found in the spermatic cord?

Answer 7

1. Testicular
2. Cremasteric (from inferior epigastric)
3. Artery to the ductus (from vesicle)

Question 8

What are the three nerves passing through the spermatic cord?

Answer 8

1. Genital branch of genito-femoral
2. Visceral sensory
3. Ilioinguinal (not really!)

Question 9

What are the other contents of the spermatic cord?

Answer 9

1. Testicular veins (pampiniform plexus)
2. Lymphatics
3. Ductus deferens

Question 10

What is a hernia?

Answer 10

• Protrusion of an organ or structure in part or in whole through a defect in the cavity that normally contains it.

Question 11

What is the inguinal triangle?

Answer 11

• A region of the lower, anterior abdominal wall, or groin.
• Contents: does not contain any structures of clinical importance.
  *Its an area of potential weakness in the abdominal wall – through which herniation of the abdominal contents can occur.

Question 12

What are the borders of the inguinal triangle?

Answer 12

1. Medial border: Lateral margin of the rectus Abdominis muscle.
2. Supero-lateral border: Inferior epigastric vessels.
3. Inferior border: Inguinal ligament.

Question 13

What is difference between direct and indirect hernia?

Answer 13

• Direct: Develops over time due to straining and is caused by weakness in the abdominal muscles. Common in adult males and rare in children.
• Indirect: Caused by a defect in the abdominal wall that will typically have been present since birth.

Question 14

What is a direct inguinal hernia?

Answer 14

• A protrusion of abdominal contents through the transversalis fascia within Hesselbach’s/ inguinal triangle.
• Through the medial fossa at the inguinal triangle.

Question 15

What is an indirect inguinal hernia?

Answer 15

• The abdominal contents protrude through the internal inguinal ring and into the inguinal canal.
• Through the lateral fossa and through the inguinal canal.

Question 16

How do hernias become complicated?

Answer 16

• When the hernia progresses through the fatty tissue and becomes trapped in the muscle. This leads to strangulation of the hernia and can lead to avascular necrosis.

Question 17

What are the signs and symptoms of a strangulated hernia?

Answer 17

1. Symptoms:
   - Pain, vomiting, distention, no flatus.
2. Signs:
   T- Tense
   I- Irreducible
   P- Painful
   I- Impulsatile
   T- Tender
   *+/- Bulged skin.