Inguinal Hernias: The Difference Between Direct vs. Indirect & Why it Matters for Sonographers

Hernias are a bulge of an organ outside of the space in which it is normally contained.  Inguinal hernias are the most common type of external hernia.  They account for 80% of the external hernias followed by incisional hernias which account for 10%, femoral hernias which account for 5%, and umbilical hernias which account for 4%.  From the perspective of a sonographer, the inguinal hernias get lumped together with femoral hernia because of their proximity in the groin region.

Hernias are easy to locate when there is a definite bulge or lump but patients may also present with a heavy discomfort, a pain in the region of interest and constipation.  A cough or valsalva maneuver (having the patient bear down as if they are about to have a bowel movment) may provide pressure to the hernia and enlarge the bulge.

The primary job of the sonographer is to locate the pathology.  If a hernia is located, pictures of hernia with and without valsalva are helpful.  There are times when I need to scan a patients while they are standing to make the hernia more apparent with the help of gravity.  This can be awkward, but if it helps get the information you are seeking it is worth a try.  If your equipment has cine capabilities that is helpful too.  Note if you can see peristalsis of the bowel contents.  Sometimes a hernia is fat containing you won’t see the motion within the bowel that has herniated through the abdominal wall.

Assuming you have located an inguinal hernia, you need to define its location as direct or indirect.  If there is a chance the patient is going to have surgery this detail is helpful to their doctor.  The landmark you need to find within the pelvic region is the inferior epigastric artery.  The inferior epigastric artery will come off of the external iliac artery at an oblique angle and will be found medial to the spermatic cord.  The intestines will bulge through the abdominal wall and either be located medial or lateral to the inferior epigastric artery.  When an inguinal hernia goes into the scrotum that is an easy call of an indirect inguinal hernia.  An indirect hernia has followed the path of least resistance along the spermatic cord and sort of fallen into the scrotum from a point lateral to the inferior epigastric artery.  A direct inguinal hernia will be found medial to the inferior epigastric artery.

Bonus info:  If you really want to show your radiologist or doctors that you know your anatomy throw in the term “Hesslebach’s Triangle”.  That is the area where direct hernias occur.  It is the anatomical region bordered by laterally by the inferior epigastic artery, inferiorly by the inguinal ligament, and medially by the rectus abdominus.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s