4. Abdominal Wall Hernias. Flashcards
What stimuli do viscera respond to?
Stretch, inflammation, ischaemia
How is visceral pain described and where is it usually felt?
Diffuse, Crampy pain, not localized. Often midline
What signs/symptoms may accompany visceral pain?
Nausea, vomiting, sweating
What are the origins of sympathetic innervation to the gut?
T5-L2
How is visceral pain transmitted?
Sensory afferent fibres via the sympathetics outflow to gut (go in reverse)
Why is visceral pain poorly localised?
Low density of sensory innervation. Sensory afferent fibres converge with somatic afferents at the same spinal level at the dorsal horn. Brain interprets visceral afferent to be coming from dermatomes of that level
Define hernia.
A protrusion of part of the abdominal contents beyond their normal confines of the abdominal wall/its containing cavity
What are the signs and symptoms of hernias that are not stuck?
Fullness of swelling
Gets larger when intraabdominal pressure increases
Aches
What are the signs and symptoms of incarcerated hernias?
Pain
Cannot be moved
Nausea and vomiting
Systemic problems if bowel has become ischaemic
What is a hernia that is stuck called?
Incarcerated hernia
What are the 2 major general causes of hernias?
Weakness in the containing cavity and anything that increases intra-abdominal pressure
Why might there be weakness in the containing cavity?
- Congenitally related
- Post surgery where wounds have not healed adequately (incisional hernia)
- Normal points of weakness
What are incisional hernias?
Hernia that occurs through a previously made incision in the abdominal wall, ie the scar left from a previous surgical operation
Give 3 examples of things that may increase intra-abdominal pressure.
- Obesity
- Weightlifting
- Chronic constipation/coughing
What are the 3 parts that make up a hernia?
- The sac
- Contents of the sac
- Coverings of the sac
which hernias can be reduced?
hernias that are not incarcerated
what is the sac?
a pouch of peritoneum
what are the contents of the sac?
• Any structure found within the abdominal cavity
o Commonly Loops of bowel/Omentum
what are the coverings of the sac?
• Consist of the layers of the abdominal wall through which the hernia has passed
What is the most common type of hernia? Name 3 some other types.
Inguinal hernias - most common
Femoral
Umbilical
Incisional
Define inguinal canal.
Oblique passage through the lower part of the abdominal wall
Where does the inguinal canal run to and from in males? In females?
Structures pass through abdomen-testis
Round ligament goes from uterus - labium majus
Whats forms the anterior border of the inguinal canal?
Aponeurosis of the external oblique muscle
What forms the inferior border (floor) of the inguinal canal?
Inguinal ligament