Hernias

• Epigastric hernia

This herniation is through the linea alba of which allows attachment of the abdominal muscles. It occurs in the upper midline of the abdomen.

It is often 2º to a chronic raise in intra-abdominal pressure (ascites, pregnancy, obesity).

It is fairly common and affects mostly middle-aged men.

It may present as an upper midline mass that disappears when lying on the back, but is asymptomatic.

This is a herniation through the linea alba, but around the umbilical region. Once again 2º to a chronic raise in intra-abdominal pressure. It presents as a lump around the umbilical region. They contain pre-peritoneal fat and sometimes bowel. They rarely strangulate.

An umbilical hernia is very similar, but rather it herniates straight through the umbilicus.

• Spigelian hernia

This is a rare type of hernia that occurs through the semilunar line (which is the tendinous lateral border of the rectus abdominus where the aponeuroses fuse). It occurs at the level of the arcuate line.

It presents as a small tender mass at the lower lateral edge of the rectus abdominus.

They tend to have narrower bases and therefore the risk of strangulation is high and requires surgical repair urgently.

Ultrasound may aid diagnosis.

This is a herniation through the obturator foramen of the pelvis, into the pelvic floor. As women have wider pelvises, they tend to have it more frequently, especially in elderly. It also presents in patients who have undergone rapid weight loss as the obturator canal tends to carry a significant amount of fat.

Patients present with a mass in the upper medial portion of the thigh, with features of small bowel obstruction.

The obturator nerve passes through the obturator foramen and in half of the cases there may be compression of the obturator nerve. We can asses this through a positive Howship-Romberg sign (hip and knee pain which worsens with thigh extension, medial rotation and abduction).

• Littre’s hernia

This is a rare form of a herniation of a Meckel’s diverticulum, commonly occurring in the inguinal canal, often becoming strangulated.

• Lumbar hernia

Rare, posterior hernias that happen iatrogenically (after open renal surgery) or spontaneously. They present as a posterior mass with back pain.

• Richter’s hernia

⬅️ This can occur anywhere in the abdomen. It is a partial herniation of the bowel where the anti-mesenteric border becomes strangulated. Part of the lumen will become strangulated while part of it will still be in the correct position and patent. However, due to the risk and due to obstruction it is a surgical emergency nevertheless.

Typical features include:

• Soft lump
1. That is protruding
2. May be reducible
3. May protrude on coughing/raising the intra-abdominal pressure
4. Aching, pulling, dragging sensation

We have a couple of layers making up the anterior abdominal wall:

1. Camper’s fascia
2. Scarpa’s fascia
3. Investing fascia (E, I, T)
4. Transversalis fascia
5. Extraperitoneal fat
6. Parietal peritoneum

The inguinal canal runs from the deep inguinal ring → superficial inguinal ring. The deep inguinal ring opens up at the tranversalis fascia while the superficial inguinal ring opens at the level of the aponeurosis of the external oblique.

There are 2 types of inguinal hernias:

• Direct inguinal hernia - 20%. This is when the bowel passes through Hesselbach’s triangle, directly into the inguinal canal
• Indirect inguinal hernia - 80%. This is when the bowel passes through the deep inguinal ring due to incomplete closure of the processus vaginalis.

⚠️ Risk factors

• Male
• Increasing age
• Raised intra-abdominal pressure - chronic cough, heavy lifting, chronic constipation
• Obesity

😷 Presentation

• Lump in the groin (superiomedial to the pubic tubercle) which may reduce manually with minimal pressure or when lying down.

💭 Differential diagnosis

Femoral hernia

Saphena varix

Inguinal lymphadenopathy

Lipoma

Groin abscess

Hydrocoele

Varicocoele

Testicular malignancy

• Surgical intervention is offered to symptomatic patients. Patients with evidence of strangulation need urgent surgery.
• Open hernia repair - using Lichtenstein technique. Preferred with patients with primary inguinal hernias. More cost-effective.
• Laparoscopic repair - total extraperitoneal (TEP) or trans-abdominal pre-peritoneal (TAPP). Preferred in patients with recurrent/bilateral inguinal hernias. Less complications, less post-operative recovery and pain. Females and patients in risk of chronic pain, laparoscopic repair is recommended.

🚨 Any presence of obstruction, incarceration, strangulation will require urgent surgery.

🚨 Complications

Post-operative complications include pain, bruising, haematoma. Less commonly infection and urinary retention.

Chronic pain occurs in up to 1/3rd of patients.

There is potential for damage to the vas-deferens leading to orchitis and infertility.

Pathophysiology

The femoral sheath contains the femoral artery, femoral vein and the femoral canal (containing lymphatics). It runs from the femoral ring → saphenous ring. A femoral hernia occurs when abdominal contents or the omentum passes through into the canal via the femoral ring.

Let’s look at the borders of the femoral ring quickly:

• Anterior border - inguinal ligament
• Posterior border - pectineus muscle
• Lateral border - femoral vein
• Medial border - lacunar ligament

The lacunar ligament especially is prone to issues that allow for femoral hernias.

• Female - wider gap between inguinal ligament and pelvic bone in females
• Pregnancy - widens the femoral canal

• Increased intra-abdominal pressure -chronic cough, constipation, weightlifting
• Increasing age - more affiliated with chronic increase in IAP

💭 Differential diagnosis

1. Inguinal hernia
2. Lipoma
3. Lymph node
4. Saphena varix (disappears when lying flat and has palpable thrill when coughing)
5. Femoral artery aneurysm

🧰 Management

🔍 Investigations

• Emergency surgeries - 2x risk compared to electives
• Obesity
• Midline incision - 74% increased risk compared to para-midline
• Wound infection
• Diabetes

• Connective tissue disorders
• Steroids
• Increasing age
• Smoking

• IVC - T8
• Oesophagus - T10
• Aorta - T12

However, there may be congenital or acquired points of weakness. Acquired means traumatic. This enables abdominal contents to pass through into the thoracic cavity, thus requiring surgery.

Acquired/traumatic diaphragmatic hernias will not be discussed in this section.

In adults it may result in:

• Dyspnoea
• Atypical chest pain
• Bowel obstruction

There are 2 types of congenital diaphragmatic hernias:

1. Bochdalek hernia - these are more common (1 in 5000 births). It occurs as a result of a defect within the posterior attachment of the diaphragm. More commonly on the left side. These are often small. 1/4 will contain abdominal organs (liver, bowel, spleen).
2. Morgagni hernia - the foramen of Morgagni is the space between the xiphoid process and the costochondral attachment of the diaphragm, anteriorly. It is more common on the right side.

😷 Presentation

They often present perinatally (although they can be asymptomatic).

When occurring in-utero it can cause:

• Pulmonary hypoplasia as the lungs don’t have as much space to grow due to the bowel herniating through the diaphragm.
• Respiratory compromise postnatally.
• Tinkling/bowel sounds on auscultation of the precordium.