Five Unusual Hernias
Frederick Ilgenfritz, MD
Bitterroot General & Vascular Surgery
If someone tells you they had to have a hernia repair, you would ordinarily
think of just a few common types they might have had. Most often, you
would think of the typical inguinal hernia (in the groin area); or perhaps
the umbilical (belly button) hernia. Another common type is an incisional
hernia at the site of a previous operation. There are, however 15 or twenty
different types of hernias, some of which are quite rare and a bit interesting.
To understand a Spigelian hernia you first need a little anatomy lesson.
The front wall of the abdomen is composed of several layers of muscle.
At the point where the mid-abdominal rectus muscles (think: six pack abs)
transition to the flat muscles of the flank there is an area of fibrous
tissue that was described by Dr. Adriaan Van der Spieghel in the 1700's.
This transition zone is called the semilunar line and extends up and down
at the edge of the rectus muscles. In this fibrous tissue and just below
the belly button a weak place can develop and through the weak place some
of the abdomen's contents can protrude outward. This can be fatty
tissue, or even a portion of bowel. This is called a spigelian hernia.
Spigelian hernias account for about 1-2 % of all hernias and are slightly
more common in women. They can be difficult to diagnose, but are easily
repaired once found.
The Richter's hernia is a bit different from the others in this group
in that it can happen at multiple locations. In this hernia, the issue
is that it involves only a portion of the bowel wall. This means that
the bowel is not obstructed and only a knuckle of the wall is stuck in
the hernia. The problem is that this portion that is stuck may become
strangulated and die. This can then result in perforation of the bowel
at that site and contamination of the abdomen. Since laparoscopic surgery
has become quite frequent, the incidence of Richter's hernias has
increased at the site of placement of the laparoscopic trochars. When
removed, these trochars can leave a small defect in the abdominal wall
for the bowel to become stuck in. Richter's hernias can occur at any
small defect in the abdominal wall. The defining feature is that only
a portion of the bowel wall is involved. The Richter's hernia is relatively
rare but must always be kept in mind when a patient has severe localized
abdominal pain and no clear explanation.
Amyand's Hernia and DeGarengeot's Hernia
This hernia is named after the English surgeon who performed the first
successful appendectomy in 1735. In an Amyand's hernia, the appendix
is found inflamed in an inguinal hernia. This is usually treated with
an appendectomy and hernia repair at the same setting. DeGarengeot's
Hernia is similar, in that, the appendix is found in a hernia. Rene Jacques
Croissant de Garengeot was an 18th century Parisian surgeon. He was the
first to describe the appendix in a femoral hernia. In both of these hernias
the need for operation is clear but the diagnosis at the start of surgery
is usually incarcerated hernia and it is only during surgery that the
appendix involvement is discovered.
Hernia of Littre
The hernia of Littre is the presence of a Meckle diverticulum in a hernia.
The common sites are inguinal (50%), umbilical(30%) and femoral(20%).
A Meckle diverticulum (first described by Alexis de Littre in 1700) is
a congenital abnormality of the last two feet of the small bowel. It is
an outpouching of the small bowel in that area with all layers of the
bowel wall, and a hollow center just like the bowel. It can contain abnormal
lining cells such as stomach or pancreas cells. It is usually about 2
inches long. In the case of a hernia of Littre it can work its way into
a hernia, become stuck, and cause symptoms. As with the Amyands and DeGarengeot's
hernias, it is usually diagnosed at surgery rather than suspected ahead
of time. The treatment is to remove the diverticulum and then close the hernia.
Ultimately these unusual hernias are interesting because of the unusual
combinations of anatomy they represent and the history behind their names.
They represent a small but intriguing part of the surgeons practice. They
end up being treated much the same as their more common cousins, but do
provide a stir of special interest when they occur.