Hernia Anatomy Flashcards
What is a hernia
Abnormal protrusion of a viscus through an abnormal opening in the wall of the cavity which it is normally contained.
It can be congenital or acquired
What are the descriptions of hernias
Reducible, incarcerated, strangulated
What are the parts of a hernia
Neck
Body
Sac
What are the types of hernias
- Inguinal (96%) -
- Femoral (4%)
- Abdominal wall hernia
- Internal Hernia
- Parastomal Hernia
What are the 6 layers of the anterior abdominal wall
- Skin and subcutaneous tissue
- Superficial (camper’s facia- continuous with superficial fat of body and scarpa’s facia - from the fascia lata of the thigh) - superficial vessels and nerves run between these layers
- Myofascial layer of abdominal wall muscles, fascial interface and rectus sheath
- Transversalis fascia
- Extra peritoneal fat
- Parietal peritoneum
What are the abdominal wall muscles
Horizontal:
External oblique
Internal oblique
Transversus abdominis
Vertical
Rectus abdominis
Pyramidalis
Origin, insertion, nerve supply of External oblique
O: Ribs 5-12
I: Iliac crest and pubic tubercle
N: Thoracoabdominal + subcostal nerve
Origin, insertion, nerve supply of internal oblique
O: Lumbar fascia, pubic crest, inguinal ligament
I : Costal margin, rectus sheath, conjoint tendon
N: thoracoabdominal nerves + subcostal nerves + ilioinguinal nerve
Origin, insertion, nerve supply of transversus abdominis
O: Inguinal ligament, iliac crest and lumbodorsal fascia
I: Costal margin, aponeurosis of rectus sheath, conjoint tendon
N: thoracoabdominal nerves + subcostal nerves + ilioinguinal nerve
Origin, insertion, nerve supply of rectus abdominis
O: Pubic line
I: Xiphoid process and 5-7th costal cartilage
N: thoracoabdominal nerves
What are the thoracoabdominal nerves, subcostal nerve and ilioinguinal nerve?
Thoracoabdominal - anterior rami of intercostal nerves t7-t11
Subcostal nerve - T12
Ilioinguinal nerve - L1
What are the fascial interfaces of the anterior abdominal wall
Linea alba - midline decussation of anterior abdominal wall
Linea semilunaris - lateral border of rectus
What is the rectus sheath
Aponeuroses of external oblique, internal oblique and transversus abdominis
What are the layers of the rectus sheath
Varies depending on above or below the arcuate line
Arcuate line - lower limit of posterior rectus sheath, where inferior epigastric vessels from external iliac vessels perforate rectus abdominis to anastamose with superior epigastric vessels from internal thoracic vessels
Above arcuate line: Anterior rectus sheath is the aponeuroses of EO and IO
Posterior rectus sheath is aponeurosis of IO, TA and transversalis fascia
Below arcuate line: Anterior rectus sheath is aponeurosis of EO, IO and TA
Posterior rectus sheath is deficient
How to inspect hernia patient
- General inspection to check for BMI, abdominal scars, bulge on neck flexion and cough impulse
- Location of hernia - congenital weak spots?
- Reducibility - Hernia is either reducible , incarcertaed (cannot be reduced) or strangulated when venous upply is compromised
- Size of hernia neck - smaller size = higher likelihood of strangulation
- Overlying skin changes
- Loss of abdominal domain
