Abdominal Wall and Hernias Flashcards
Define hernia
Protrusion of part of the abdominal contents beyond the normal confines of the abdominal wall
State the contents of a hernia
- The sac - pouch of peritoneum
- Contents of the sac - any structure found within the abdominal cavity
- Commonly loops of bowel, omentum
- Coverings of the sac
- Consist of the layers of the abdominal wall through with the hernia has passed
Describe areas of potential weakness in the abdominal wall
- Inguinal canal
- Femoral canal
- Umbilicus
- Previous incisions
Describe the contents of the inguinal canal
- In males, spermatic cord passes from abdomen to testis
- In females, round ligament goes from uterus to labium majus
Describe the formation of tunica vaginalis
- Processus vaginalis is a pouch of peritoneum
- Develops and moves downwards
- Obliterates and becomes tunica vaginalis
- Gubernaculum - condensed band of mesenchyme that links inferior portion of testis to labioscrotal swelling
- Shortens which draws testis down
- Failure of obliteration of processus vaginalis creates a connection between peritoneum and scrotum
Describe the borders of the inguinal canal
- Anterior border - aponeurosis of external oblique
- Inferior border (floor) - inguinal ligament = thick layer of external oblique aponeurosis, lacunar ligament which reinforces medially
- Roof - anterior fibres of internal oblique, transverse abdominus
- Posterior border - transversalis fascia, conjoint tendon
Describe the deep ring of the inguinal canal
- Deep ring is the entrance to the inguinal canal
- Located on the posterior wall (transversalis fascia)
Describe the superficial ring of the inguinal canal
- Superficial ring is the exit of the inguinal canal
- Located on the anterior wall (aponeurosis of external oblique)
Describe the location where indirect and direct hernias enter the inguinal canal
- Indirect hernias leave from deep ring
- Lateral to inferior epigastric vessels
- Where hernia leaves abdominal wall
- Direct hernias straight through abdominal wall
- Medial to inferior epigastric vessels
Describe the significance of Hesselbachs triangle
- Location of weakness in abdominal wall
- Where direct hernias occur
- Medial border - rectus abdominus muscle
- Inferior border - inguinal ligament
- Superior border - inferior epigastric artery
Describe the effect of indirect inguinal hernia
- Failure to obliterate processus vaginalis
- Passes through deep inguinal ring and into the inguinal canal and leave through superficial inguinal ring
- Depending on where the processus vaginalis was obliterated, can potentially descend into the scrotum
- Intestines exit alongside the spermatic cord
Describe a direct inguinal hernia
- Bulges through Hesselbach’s triangle
- Occurs more in male, > 40 age (muscles weaken with age)
- Generally in the vicinity of the superficial inguinal ring
- Doesn’t enter inguinal canal as not entered from deep ring, however weakness at superficial ring means hernia exits around there
- Enter medially to inferior epigastric vessels
Describe a strangulated hernia
- Swelling causing blood supply to hernia being compromised
- Leads to sepsis from ischaemia
- Common in indirect hernias and femoral hernias
What is an incarcerated hernia
- A hernia that cannot be pushed back in
- A hernia which can be pushed back in is called reducible hernia
Describe the anatomy of femoral hernias
- In NAVEL, femoral canal is the empty space
- Lateral is femoral vein
- Medial is lacuna ligament
- Femoral ring -> lacuna ligament -> saphenous opening
Describe types of umbilical hernia
- Congenital
Omphalocele- Contents herniate into umbilical cord
- Has peritoneal covering
- Different to gastrochisis - no peritoneum covering (more dangerous)
- Inflammation from contact with amniotic fluid
- Acquired infantile
- Contents herniate through weakness in scar of umbilicus
- Skin over hernia - resolves after couple years
- Contents herniate through weakness in scar of umbilicus
Describe epigastric hernia
- Occurs through linea alba
- Usually starts with small hernia (extra-peritoneal fat poking through linea alba)
- Chronic straining forces more fat on which can eventually pull peritoneum through
