S4) Abdominal Wall and Hernias Flashcards
What is a hernia?
A hernia is a protrusion in the fascia of part of the abdominal contents beyond the normal confines of it containing cavity e.g abdominal wall
A hernia contains 3 parts.
Identify them
- The sac
- Contents of the sac
- Coverings of the sac
What is the sac of a hernia?
The sac is a pouch of peritoneum
What are the contents the sac of a hernia?
- Contents are any structure found within the abdominal cavity
- Commonly: loops of bowel and omentum
What does the covering of the sac of a hernia consist of?
Covering of sac consists of the layers of the abdominal wall through with the hernia has passed
What generally causes abdominal hernias?
Weaknesses in abdominal wall due to genetics, surgery or normal points of weakness
Identify 4 points of weakness in the abdominal wall
- Inguinal canal
- Femoral canal
- Umbilicus
- Previous incisions
What is the inguinal canal?
The inguinal canal is an oblique passage through lower part of the abdominal wall
Distinguish between the contents of the inguinal canal in males and females
- Males: structures pass through from abdomen-testis
- Females: round ligament goes from Uterus-labium majus
What is the inguinal canal made up of?
- Anterior and posterior walls
- Superficial and deep rings (openings)
- Roof and floor (superior and inferior walls)
What composes the anterior wall of the inguinal canal?
The anterior wall is formed by the aponeurosis of the external oblique, and reinforced by the internal oblique muscle laterally
What composes the posterior wall of the inguinal canal?
The posterior wall is formed by the transversalis fascia and conjoint tendon
What composes the roof of the inguinal canal?
The roof is formed by the transversalis fascia, internal oblique and transversus abdominis
What composes the floor of the inguinal canal?
The floor is formed by the inguinal ligament and thickened medially by the lacunar ligament
Describe the location and formation of the deep ring
- The deep ring is found above the midpoint of the inguinal ligament
- The ring is created by the transversalis fascia
- it is the only entrance to the inguinal Canal
The superficial ring marks the end of the inguinal canal.
Describe its location and its formation
- The superficial ring lies just superior to the pubic tubercle
- Formed by the evagination of the external oblique
- it forms the only exit of the inguinal canal
What are the different types of abdominal hernias that occur and how often do they occur?
- 75% Inguinal
- 10% Umbilical
- 10% Incisional
- 3-5% Femoral
What two types of inguinal hernias are there?
- Indirect (2/3)
- Direct (1/3)
What is an indirect inguinal hernia?
Indirect inguinal hernia is when the peritoneal sac enters the inguinal canal through the deep inguinal ring and passes through the canal to the superficial inguinal ring
How can one determine the severity of the indirect inguinal hernia?
- The degree to which the sac herniates depends on the amount of processus vaginalis still present
- It can potentially descend into the scrotum
Who is more likely to get an indirect inguinal hernia and how is it likely to occur?
- Males (7:1)
- Mainly right sided
What is a direct inguinal hernia?
- Direct inguinal hernia is where the peritoneal sac enters the inguinal canal through the posterior wall of the inguinal canal
- It bulges through Hesselbach’s triangle and is in the vicinity of the superficial inguinal ring
- does not travel through the deep inguinal ring only the superficial one - the hernia therefore does not enter the inguinal canal as it is passing through the exit
What are the boundaries of Hesselbach’s triangle?
- Lateral: inferior epigastric artery
- Medial: lateral border of rectus abdominus
- Inferior: inguinal ligament
What is the anatomical difference between direct and indirect inguinal hernias?
- Indirect inguinal hernia: lateral to the inferior epigastric vessels
- Direct inguinal hernia: medial to inferior epigastric vessels
