What is that Bulge? - The Pediatric Inguinal Hernia

Pediatric inguinal hernia repairs are one of the most common procedures performed by pediatric surgeons. And parents will present to us with a child who has a bulge in the groin area - most often seen during a diaper change, most visible when the child is crying which will then disappear when the child is calm.

A hernia is an opening in the abdominal wall through which a "sac" pushes through that defect from the abdominal cavity.  Many parents do not understand the difference between a pediatric inguinal hernia which is a congenital defect (present at birth) and an adult inguinal hernia which is a defect due to lifestyle, or picking the wrong parents (inherited connective tissue disorders).

During development the fetus is a blank canvas until the interplay of genes and hormones;  around 30 weeks of gestational age the testicles, which develop just below the kidneys are signaled by testosterone to move from this location into the scrotum.  When they do this they pull an extension of the abdominal lining along with them.  This "sac" around the testicles persists for life, but the path of the "process vaginalis", the connection to the abdomen closes entirely by at most the first month of life.  If it does not a hernia is created which is visible when contents from the abdominal cavity are in the sac. As the abdominal wall gets stronger, the child can push abdominal contents into this pathway, often making the small defect larger over time.  Since the left descends first, hernias are more common on the right, which is the last side to close.

Now that we know what they are; who is more likely to present with an inguinal (the crease between the abdomen and the top of the leg) hernia?

Risk factors:

     -prematurity

     -undescended testicles

And girl mommas you are not free, because even though girls don't have testicles they do have this same pathway, so they can develop hernias too.  For girls, it is often the fallopian tube and the ovary that fall into the sac.

So if it's natural, why is it a problem?  Because occasionally, in both boys and girls, a loop of the intestine can get stuck in that canal and cannot return to the abdominal cavity.  If the loop cannot be gently pushed back into the abdominal cavity, that section may lose its blood supply, become necrotic and die.  This becomes a surgical emergency.  Unfortunately, babies have only one mode of communication and as any new mother knows a cry can be from a  dizzying array of demands: "I'm wet, I'm cold, I'm hot, I'm in pain" to "I miss you".

If seen while your child is in the NICU, this author recommends repair before discharge to home.  For an elective repair inguinal hernia repair is a same-day procedure, however, if the baby was born premature (<37 weeks) and is less than a total of 60-week post gestation in age (time in mom's tummy + time since birth) it is recommended that they be admitted overnight for observation on a cardio-respiratory monitor as there is a risk for infants at this age to have post-anesthesia apnea (stop breathing).

If your child has been fortunate enough to bypass the NICU, then you may discover that bulge during a diaper change.  And as babies don't read the textbooks, invariably they will refuse to produce that bulge during your visit to the pediatrician.  This is the 21st century and even my 7 year has photographic technology at his disposal, so save yourself the anguish and just take a picture.  Physical exams are very experience-dependent and ultrasounds of the groin are neither specific nor sensitive depending on the size of the defect.

So we have discussed the what, the why, and the who, and now my part is the repair.

As I stated before inguinal hernia repairs are one of the most common procedures performed by either pediatric general surgeons or pediatric urologists.

Traditionally this was done with either general or spinal anesthesia via a groin incision over the symptomatic side.  The hernia sac was identified as isolated and the vas deferens (the tube that brings mature sperm) and vascular structures (arteries and veins), which are usually adherent to the sac were peeled off and the sac was cut and free ends tied, so that the path connecting the abdominal cavity to the scrotal sac was obliterated.  Originally surgeons just worked the odds as to the existence of a path on the other side, if the left was symptomatic, odds were likely there was a silent hernia on the other side and a bilateral exploration was offered.  

With the advent of the laparoscope, we were able to use the open hernia sac as a window and would place a scope through the sac to look at the opposing side.  If an open tract was seen we would offer repair.  However, sometimes the sac was too thin and we were unable to place the scope through this delicate tissue.

As medicine has progressed we can now perform a completely laparoscopic repair, which is this author's preference.  Using a small camera through the umbilicus we can visualize both the left and the right side and repair the defects entirely without an open incision.  The benefit is direct visualization of the vas deferens and vessels without ever touching them during the repair.  Also, both sides can be seen without "playing the odds".  In addition, if there is a small umbilical hernia, I close it upon removal of the umbilical laparoscope.  The drawback is that because the patient must be paralyzed for the procedure it requires full general anesthesia, spinal is not an option.

I often get asked about mesh, which is not necessary for a pediatric repair.  I am not repairing weakened tissue, by removing a path that should not be present.

If knowledge is power, and I believe it is, I hope I have empowered you, dear reader.