Inguinal canal and hernias Flashcards
Define hernia
Protrusion of a tissue or organ through a retaining tissue
What does the inguinal ligament span between?
ASIS and pubic tubercle
At what point does the external iliac artery become the femoral artery?
When it passes behind the inguinal ligament into the thigh
Where is the mid-inguinal point?
Where is the midpoint of inguinal ligament?
Mid-inguinal point: 50% of way between ASIS and pubic symphysis
Midpoint of inguinal ligament: 50% of way between ASIS and pubic tubercle.
Where does the pulsation of the femoral artery sit?
What is this an approximate marker for?
+/- 1cm from mid inguinal point
Approximate marker for the location of the deep inguinal ring (entrance to the inguinal canal)
Where are the origins of a femoral and inguinal hernia?
Inguinal: above/ above and medial to the pubic tubercle
Femoral: below the level of the pubic tubercle
Name some common abdominal wall hernias
Who are they most common in?
Umbilical: most common in newborns and women post pregnancy (separation of rectus abdominis)
Inguinal: most common in males as testicles descend through the inguinal canal, larger aperture in males.
Femoral: more common in females due to wider pelvis
Where do some common posterior abdominal wall hernias occur?
Inferior lumbar triangle
Superior lumbar triangle
What are the borders of the inferior lumbar triangle?
Lateral border: external oblique
Medial border: latissimus dorsi
Inferior border: iliac crest
What are the borders of the superior lumbar triangle?
Superior border: rib 12
Lateral border: internal oblique
Medial border: quadratus lumborum
What forms the deep inguinal ring?
Where is it located?
Invagination of the transversalis fascia
Located between midpoint of inguinal ligament and mid inquinal point 1cm above inguinal ligament.
What forms the superficial inguinal ring?
Where is it located?
What emerges through it?
External oblique aponeurosis
Located superolateral to the pubic tubercle
Point of emergence for spermatic cord in males and round ligament and its coverings in females.
What are the contents of the female inguinal canal?
Round ligament of uterus
Lymphatics from uterus
Ilioinguinal nerve
Genital branch of genitofemoral nerve
What are the contents of the male inguinal canal?
Spermatic cord and its contents
Ilioinguinal nerve
Genital branch of femoral nerve
Where do the testicles and ovaries develop?
Are they intra or retroperitoneal at this stage?
On the posterior abdominal wall
Retroperitoneal
What is the tunica vaginalis?
Fold of peritoneum that descends with the testes through the inguinal canal. It is retained in males and allows free movement of the testes in the scrotum,
What is the processus vaginalis?
The double layered loop of peritoneum pulled through the inguinal canal along with the testes. Gives rise to the tunica vaginalis.
Normally fuses but can remain patent causing predisposition to inguinal hernias.
What are the borders of the inguinal canal?
Anterior: external oblique aponeurosis
Posterior: transversalis fascia
Roof: transversalis fascia, transversus abdominis and internal oblique
Floor: inguinal ligament
How do the internal oblique and transversus abdominis provide support to the superficial inguinal ring?
What do they form?
They arch over the top of the inguinal canal and attach to the pubic tubercle. They travel infero-medially, providing support to the posterior wall.
They form the conjoint tendon
What is a direct inguinal hernia?
Where do they always occur?
Peritoneal sac passes through to the inguinal canal via the posterior wall out of the superficial ring. Often caused by weakness of the conjoint tendon.
Occur medial to the inferior epigastric artery in Hesselbach’s triangle.
What is an indirect inguinal hernia?
Where do they always occur?
Peritoneal sac passes through deep inguinal ring into the inguinal canal and out of the superficial inguinal ring.
Occur lateral to inferior epigastric artery, often due to failure of the processus vaginalis to fuse. Extend of protrusion depends on the degree of processus vaginalis that remains.
What are the borders of Hesselbach’s triangle?
Lateral: inferior epigastric artery
Medial: rectus abdominis
Lower: inguinal ligament
What is at risk in inguinal canal/lower abdominal wall surgery?
What can be the consequences if they are damaged?
- Iliohypogastric nerve
- Damage= muscle paralysis/weakness in lower abdomen and conjoint tendon; predisposition to direct hernias.
- Ilioinguinal nerve (most at risk- travels through part of inguinal canal)
- Changes/loss of sensation to anterior scrotum and proximal penis/ anterior labia majora.
How does the ilioinguinal nerve pass through the inguinal canal?
Enters laterally (not through the deep ring) and exits through the superficial canal.
