6) Hernias Flashcards
What is a hernia?
Protrusion of part of the abdominal contents beyond the normal confines of the abdominal wall
What 3 parts does a hernia consist of?
Sac
Contents
Covering
What is the sac?
Pouch of peritoneum
Generally, what are the contents for a hernia?
Any structures found within the abdominal cavity
Commonly, loops of bowel or ommentum
What is the covering of a hernia?
Layers of abdominal wall through which the hernia has passed
What weaknesses in the abdominal wall may a hernia pass through?
Inguinal canal
Femoral canal
Umbilicus
Previous incisions
What is the inguinal canal?
Oblique passage through lower part of abdominal wall, extends from inside peritoneal cavity to scrotum in males
What passes through inguinal canal in males?
Ilioinguinal nerve and spermatic cord
What passes through inguinal canal in females?
Ilioinguinal nerve and round ligament (from uterus to labum majus)
Why is an inguinal hernia more likely in men?
Larger and more prominent
Failure of processus vaginalis to obliterate
Where are the testes located before descent?
Posterior abdominal wall, retroperitoneal
What is the gubernaculum?
Condensed band of mesenchyme that connects testes to scrotal pouch
How do the testes descend?
Gubernaculum shortens
What is the processus vaginalis?
Outpouching of peritoneum which is anterior to testes
What usually happens to the processus vaginalis?
Obliterates to form tunica vaginalis - small amount of peritoneum covering an aspect of testicle
What leads to increased risk of inguinal hernia?
Partial recession of processus vaginalis
Why does partial recession of processus vaginalis increase risk of hernia?
Leaves a peritoneal lined pathway from peritoneal cavity to scrotum
What forms the floor of the inguinal canal?
Inguinal ligament (a rolled edge of external oblique aponeurosis) and thickened medially by the lacunar ligament
What forms the roof of the inguinal canal?
Internal oblique and transversus abdominis
What forms the posterior wall of the inguinal canal?
Transversalis fascia, conjoint tendon medially (aponeurosis of IO + TA)
What forms the anterior wall of the inguinal canal?
Aponeurosis of external oblique
What and where is the entrance to the inguinal canal?
Deep ring, posterior wall
What and where is the exit of the inguinal canal?
Superficial ring, anterior wall
What is an indirect hernia?
Hernia that is lateral to inferior epigastric vessels
What is at the mid-inguinal point?
Femoral artery, between ASIS and pubic symphysis
What is at the mid point of the inguinal ligament?
Deep inguinal ring, between ASIS and pubic tubercle
Describe the entry point and passage of an indirect hernia:
Enters through deep inguinal ring, traverses canal and exits through superficial ring
Can descend into scrotum depending on processus vaginalis obliteration
Describe the entry passage of a direct hernia:
Through Hesselbach’s triangle
What are the borders of Hesselbach’s triangle?
Medial - rectus abdominis
Lateral - inferior epigastric vessels
Floor - Inguinal ligament
What is an incarcerated hernia?
Stuck or irreducible hernia
What is a strangulated hernia?
Disruption of hernia blood supply, can result in tissue necrosis
What is a femoral hernia?
Protrusion of abdominal viscera into femoral canal through femoral ring
Why are femoral hernias more common in females?
Wider pelvis and broader femoral ring
Why is strangulation likely in femoral hernias?
Femoral ring has rigid boundaries
What is an epigastric hernia?
Protrusion through linea alba between xiphoid process and umbilicus
Chronic straining forces more fat and peritoneum out
What 3 types of umbilical hernia are there?
Congenital
Acquire infantile
Acquire adult
What is a congenital umbilical hernia?
Through umbilical ring, contents herniate into umbilical cord and have peritoneal covering
What is an acquire infantile umbilical hernia?
Herniation through weakness in scar of umbilicus
What is an acquire adult umbilical hernia?
Increased intra-abdominal pressure cause herniation through linea alba in region of umbilicus
Causes: chronic cough, obesity
