Hernias

Question 1

Generally why do hernias occur?

Answer 1

Hernias occur when there is a weak point in a cavity wall, usually affecting the muscle or fascia. This weakness allows a body organ (e.g., bowel) that would normally be contained within that cavity to pass through the cavity wall.

Question 2

The typical features of an abdominal wall hernia are:

Answer 2

A soft lump protruding from the abdominal wall

The lump may be reducible (it can be pushed back into the normal place)

The lump may protrude on coughing (raising intra-abdominal pressure) or standing (pulled out by gravity)

Aching, pulling or dragging sensation

Question 3

There are three key complications of hernias:

Answer 3

Incarceration
Obstruction
Strangulation

Question 4

Incarceration is where?

Answer 4

the hernia cannot be reduced back into the proper position (it is irreducible). The bowel is trapped in the herniated position. Incarceration can lead to obstruction and strangulation of the hernia.

Question 5

Obstruction is where?

Answer 5

a hernia causes a blockage in the passage of faeces through the bowel. Obstruction presents with vomiting, generalised abdominal pain and absolute constipation (not passing faeces or flatus).

Question 6

Strangulation is where?

Answer 6

a hernia is non-reducible (it is trapped with the bowel protruding) and the base of the hernia becomes so tight that it cuts off the blood supply, causing ischaemia. This will present with significant pain and tenderness at the hernia site. Strangulation is a surgical emergency. The bowel will die quickly (within hours) if not corrected with surgery. There will also be a mechanical obstruction when this occurs.

Question 7

TOM TIP:

Answer 7

Hernias that have a wide neck, meaning that the size of the opening that allows abdominal contents through is large, are at lower risk of complications. While the contents can easily pass out of this opening, they can also easily be put back, which puts them at a lower risk of incarceration, obstruction and strangulation. When assessing a hernia, always comment on the size of the neck/defect (narrow or wide), as this will help formulate a risk assessment and management plan for the hernia (such as how urgently they need to be operated on).

Question 8

what is Richter’s Hernia?

Answer 8

A Richter’s hernia is a very specific situation that can occur in any abdominal hernia.

This is where only part of the bowel wall and lumen herniate through the defect, with the other side of that section of the bowel remaining within the peritoneal cavity.

They can become strangulated, where the blood supply to that portion of the bowel wall is constricted and cut off.

Strangulated Richter’s hernias will progress very rapidly to ischaemia and necrosis and should be operated on immediately.

Question 9

what is Maydl’s Hernia

Answer 9

Maydl’s hernia refers to a specific situation where two different loops of bowel are contained within the hernia.

Question 10

There are general principles of management that apply to abdominal wall hernias. These are:

Answer 10

Conservative
management

Tension-free repair (surgery)

Tension repair (surgery)

Question 11

Conservative management involves ?

Answer 11

leaving the hernia alone. This is most appropriate when the hernia has a wide neck (low risk of complications) and in patients that are not good candidates for surgery due to co-morbidities.

Question 12

Tension-free repair involves?

Answer 12

placing a mesh over the defect in the abdominal wall. The mesh is sutured to the muscles and tissues on either side of the defect, covering it and preventing herniation of the cavity contents. Over time, tissues grow into the mesh and provide extra support. This has a lower recurrence rate compared with tension repair, but there may be complications associated with the mesh (e.g., chronic pain).

Question 13

Tension repair involves?

Answer 13

a surgical operation to suture the muscles and tissue on either side of the defect back together. Tension repairs are rarely performed and have been largely replaced by tension-free repairs. The hernia is held closed (to heal there) by sutures applying tension. This can cause pain and there is a relatively high recurrence rate of the hernia.

Question 14

Inguinal hernias present with a soft lump in the inguinal region (in the groin). There are two types:

Answer 14

Indirect inguinal hernia
Direct inguinal hernia

Question 15

There are a number of differential diagnoses for a lump in the inguinal region:

Answer 15

Femoral hernia
Lymph node
Saphena varix (dilation of saphenous vein at junction with femoral vein in groin)
Femoral aneurysm
Abscess
Undescended / ectopic testes
Kidney transplant

Question 16

An indirect inguinal hernia is where

Answer 16

bowel herniates through the inguinal canal.

Question 17

The inguinal canal is a tube that runs between the?

Answer 17

deep inguinal ring (where it connects to the peritoneal cavity), and the superficial inguinal ring (where it connects to the scrotum).

Question 18

In males, the inguinal canal is?

Answer 18

what allows the spermatic cord and its contents to travel from inside the peritoneal cavity, through the abdominal wall and into the scrotum.

Question 19

In females, the round ligament is ?

Answer 19

attaches to the uterus and passes through the deep inguinal ring, inguinal canal and then attaches to the labia majora.

Question 20

There is a specific finding of indirect inguinal hernias that help you differentiate them from a direct inguinal hernias:

Answer 20

When an indirect hernia is reduced and pressure is applied (with two fingertips) to the deep inguinal ring (at the mid-way point from the ASIS to the pubic tubercle), the hernia will remain reduced.

Question 21

Direct inguinal hernias occur due to?

Answer 21

weakness in the abdominal wall at Hesselbach’s triangle. The hernia protrudes directly through the abdominal wall, through Hesselbach’s triangle (not along a canal or tract like an indirect inguinal hernia). Pressure over the deep inguinal ring will not stop the herniation.

Question 22

Hesselbach’s triangle boundaries (RIP mnemonic):

Answer 22

R – Rectus abdominis muscle – medial border
I – Inferior epigastric vessels – superior / lateral border
P – Poupart’s ligament (inguinal ligament) – inferior border

Question 23

Femoral hernias involve ?

Answer 23

herniation of the abdominal contents through the femoral canal. This occurs below the inguinal ligament, at the top of the thigh.

The opening between the peritoneal cavity and the femoral canal is the femoral ring. The femoral ring leaves only a narrow opening for femoral hernias, putting femoral hernias at high risk of:

Incarceration
Obstruction
Strangulation

Question 24

Boundaries of the femoral canal (FLIP mnemonic):

Answer 24

F – Femoral vein laterally
L – Lacunar ligament medially
I – Inguinal ligament anteriorly
P – Pectineal ligament posteriorly

Question 25

Don’t get the femoral canal confused with the femoral triangle. The femoral triangle is a larger area at the top of the thigh that contains the femoral canal. You can remember the boundaries with the SAIL mnemonic:

Answer 25

S – Sartorius – lateral border
A – Adductor longus – medial border
IL – Inguinal Ligament – superior border

Question 26

Use the NAVY-C mnemonic to remember the contents of the femoral triangle from lateral to medial across the top of the thigh:

Answer 26

N – Femoral Nerve
A – Femoral Artery
V – Femoral Vein
Y – Y-fronts
C – Femoral Canal (containing lymphatic vessels and nodes)

Question 27

Incisional Hernias?

Answer 27

Incisional hernias occur at the site of an incision from previous surgery. They are due to weakness where the muscles and tissues were closed after a surgical incision. The bigger the incision, the higher the risk of a hernia forming. Medical co-morbidities put patients at higher risk due to poor healing.

Incisional hernias can be difficult to repair, with a high rate of recurrence. They are often left alone if they are large, with a wide neck and low risk of complications, particularly in patients with multiple co-morbidities.

Question 28

Umbilical Hernias?

Answer 28

Umbilical hernias occur around the umbilicus due to a defect in the muscle around the umbilicus.

Umbilical hernias are common in neonates and can resolve spontaneously. They can also occur in older adults.

Question 29

Epigastric Hernias?

Answer 29

An epigastric hernia is simply a hernia in the epigastric area (upper abdomen).

Question 30

Spigelian Hernias

Answer 30

A Spigelian hernia occurs between the lateral border of the rectus abdominis muscle and the linea semilunaris. This is the site of the spigelian fascia, which is an aponeurosis between the muscles of the abdominal wall. Usually, this occurs in the lower abdomen and may present with non-specific abdominal wall pain. There may not be a noticeable lump.

An ultrasound scan can help establish the diagnosis.

Spigelian hernias generally have a narrower base, increasing the risk of incarceration, obstruction and strangulation.

Question 31

Diastasis Recti

Answer 31

Diastasis recti may also be called rectus diastasis and recti divarication. It refers to a widening of the linea alba, the connective tissue that separates the rectus abdominis muscle, forming a larger gap between the rectus muscles. It is not technically a hernia. This gap becomes most prominent when the patient lies on their back and lifts their head. There is a protruding bulge along the middle of the abdomen.

The linea alba is the aponeurosis of the two sides of the rectus abdominis muscle. The gap is created because the linea alba is stretched and broad.

This can be congenital (in newborns) or due to weakness in the connective tissue, for example following pregnancy or in obese patients.

No treatment is required in most cases, but surgical repair is possible.

Question 32

Obturator Hernias

Answer 32

Obturator hernias are where the abdominal or pelvic contents herniate through the obturator foramen at the bottom of the pelvis. They occur due to a defect in the pelvic floor and are more common in women, particularly in older age, after multiple pregnancies and vaginal deliveries. They are often asymptomatic but may present with irritation to the obturator nerve, causing pain in the groin or medial thigh.

Howship–Romberg sign refers to pain extending from the inner thigh to the knee when the hip is internally rotated and is due to compression of the obturator nerve.

It can also present with complications of:

Incarceration
Obstruction
Strangulation

CT or MRI of the pelvis can establish the diagnosis. It may be found incidentally during pelvic surgery.

Question 33

Hiatus Hernias

Answer 33

An hiatus hernia refers to the herniation of the stomach up through the diaphragm. The diaphragm opening should be at the level of the lower oesophageal sphincter and should be fixed in place.

A narrow opening helps to maintain the sphincter and stop acid and stomach contents refluxing into the oesophagus.

When the opening of the diaphragm is wider, the stomach can enter through the diaphragm and the contents of the stomach can reflux into the oesophagus.

Question 34

What is a clinical sign specific to a hernia?

Answer 34

“Cough impulse” - Swelling expands upon coughing

Also might be less apparent whilst lying down