Lecture Notes : Hernias



Definition :
It is a protrusion of any viscus from its proper cavity. The protruded parts are generally contained in a sac-like structure, formed by the membrane with which the cavity is naturally lined.

Epidemiology :

- Approximately 25% of males and 2% of females have inguinal hernias in their lifetimes representing the most common hernia in males and females.

- Approximately 75% of all hernias occur in the groin; two thirds of these hernias are indirect and one third direct.

- Indirect inguinal hernias are the most common hernias in both men and women; a right-sided predominance exists.

- Incisional and ventral hernias ( epigastric ) account for 10% of all hernias.

- Only 3% of hernias are femoral hernias.

- The incidence of inguinal hernias in children ranges up to 4.5%, while umbilical hernias occur in approximately 1 out of every 6 children

- The incidence of incarcerated or strangulated hernias in pediatric patients is 10-20%; 50% of these occur in infants younger than 6 months .

Types : according to location

1- inguinal hernias : indirect and direct

- what are the normal structure which pass through the inguinal canal ?

in males : the spermatic cord and its coverings + the ilioinguinal nerve
in females : the round ligament of the uterus + the ilioinguinal nerve.

 

The classic description of the contents of spermatic cord in the male are:

 

3 arteries: artery to vas deferens (or ductus deferens), testicular artery, cremasteric artery;

3 fascial layers: external spermatic, cremasteric, and internal spermatic fascia;

3 other structures: pampiniform plexus, vas deferens (ductus deferens), testicular lymphatics;

3 nerves: genital branch of the genitofemoral nerve (L1/2), autonomic and visceral afferent fibres, ilioinguinal nerve (N.B. outside spermatic cord but travels next to it)

 

The ilioinguinal nerve passes through the superficial ring to descend into the scrotum, but does not formally run through the canal.

 

2- Femoral :

- more common in females

- because it is small space >> frequently it can be incarcerated or strangulated

- located medial to femoral vein and lateral to lacunar ligament

 

3- umbilical hernia :

- congenital hernia 

- repaired if it persist in children older than 2-4 years

 

4- Richter hernia :

- occurs when only the antimesenteric border of the bowel herniates through the fascial defect.

- The Richter hernia can occur with any of the various abdominal hernias and is particularly dangerous, as a portion of strangulated bowel may be reduced unknowingly into the abdominal cavity, leading to perforation and peritonitis.

 

5- Incisional hernia :

- iatrogenic hernia occurs in 2-10% 

- recurrence rates approach 20-45%

 

6- Spigelian hernia :

- rare

- defect in the spigelian fascia >> the lateral edge of the rectus muscle at the semilunar line ( costal arch of pubic tubercle)

- The two subtypes are interstitial and subcutaneous

- best defined using CT

 

7- Obturator hernia :

- passes through the obturator foramen

- female-to-male ratio of 6:1  >> larger

- Because of its anatomic position, this hernia presents more commonly as a bowel obstruction .

 

- Types of Hernia - Condition

• Reducible hernia: This term refers to the ability to return the contents of the hernia into the abdominal cavity, either spontaneously or manually.
• Incarcerated hernia: An incarcerated hernia is no longer reducible. The vascular supply of the bowel is not compromised; however, bowel obstruction is common.
• Strangulated hernia: A strangulated hernia occurs when the vascular supply of the bowel is compromised secondary to incarceration of hernia contents.

History :

- can be presented by the patient or detected in routine physical examination

- patient can be presented with :
1- lump
2- pain
3- nausea , vomiting or symptoms of intestinal obstruction ( in incarcerated hernia )
4- sepsis ( in strangulated )

- swelling in femoral region + groin pain >> femoral hernia

- Obturator hernia

• Because this hernia is hidden within deeper structures, it may not present as a swelling
• The patient may complain of abdominal pain or medial thigh pain, weight loss, or recurrent episodes of bowel or partial bowel obstruction
• Pressure on the obturator nerve causes pain in the medial thigh that is relieved by thigh flexion. This same pain may be exacerbated by extension or external rotation of the hip (Howship-Romberg sign)

- in physical examination >> Strangulated hernias are differentiated from incarcerated hernias by the following:

• Sever pain
• Fever or toxic appearance
• Pain that persists after reduction of hernia

- Causes with the risk factors :

 

Any condition that increases the pressure in the intra-abdominal cavity may contribute to the formation of a hernia, including the following:

• Marked obesity
• Heavy lifting
• Coughing
• Straining with defecation or urination
• Ascites
• Peritoneal dialysis
• Ventriculoperitoneal shunt
• Chronic obstructive pulmonary disease (COPD)
• Family history of hernias

 

- Differential Diagnoses

• Epididymitis
• Hidradenitis Suppurativa
• Hydrocele
• Lymphogranuloma Venereum
• Testicular Torsion

- in lab studies :

CBC >> -nonspecific
               -leukocytosis in strangulation

electrolyte ,BUN and Cr >> - rare
                                              - evaluate hydration status in pt with vomiting

urinalysis >> narrow DDx

lactate >> - elevated level indicate hypoperfusion
                 - normal not rule out strangulation

- complication
1- incarceration
2- intestinal obstruction
3- if it was strangulation and missed >> perforation and peritonitis
4- recurrence

- Treatment :

elective herniorrhaphy >> to prevent the chance of incarceration or strangulation

emergent herniorrhaphy >> if strangulation is suspected or acute incarceration is present