Summary

An Inguinal Hernia is the protrusion of abdominal contents (Usually bowel or omentum) through the inguinal canal into the groin. Inguinal hernias are the most common type of abdominal wall hernia (~75% of all hernias), with a lifetime risk of 27% in men and 3% in women. They are classified as Indirect (Most common, Passes through the Deep Inguinal Ring – congenital/acquired) or Direct (Passes through Hesselbach's triangle – acquired, due to muscular weakness). Patients present with a groin lump that is often more prominent on coughing/straining and may reduce when lying down. Complications include Incarceration (Irreducible) and Strangulation (Ischaemic bowel – surgical emergency). Elective surgical repair is recommended for symptomatic hernias. Options include Open (Lichtenstein mesh repair – Gold standard) or Laparoscopic (TAPP/TEP). Emergency surgery is required for strangulation. [1,2,3]

Clinical Pearls

"Indirect = Through the Ring": Indirect hernias enter the inguinal canal through the Deep Inguinal Ring (Lateral to inferior epigastric vessels). Often descend into scrotum.

"Direct = Through the Triangle": Direct hernias push through Hesselbach's triangle (Medial to inferior epigastric vessels). Do NOT descend into scrotum.

"Cough Impulse": Ask patient to cough while palpating groin – Expansile impulse = Hernia.

"If in Doubt, Take it Out": Irreducible or tender hernia = Urgent surgical assessment. Strangulation is an emergency.

Inguinal Canal

Contents

Hesselbach's Triangle

Indirect vs Direct

Other Types

Inguinodynia (Post-Herniorraphy Pain Syndrome)

Pain persisting >3 months post-op. Affects 10-12% of patients. Often debilitating.

• Causes:
  1. Direct Nerve Injury: Ilioinguinal, Iliohypogastric, or Genitofemoral nerves trapped in suture/tack.
  2. Mesh Reaction: Inflammation/Fibrosis ("Mesh shrinkage") pulling on tissues.
  3. Neuroma: Cut nerve end.
• Management Algorithm:
  1. Conservative: Analgesia (Neuropathic - Gabapentin/Amitriptyline). Wait 6 months.
  2. Diagnostic Block: Local anaesthetic injection to identify the specific nerve.
  3. Surgical: Triple Neurectomy (Ilioinguinal, Iliohypogastric, Genitofemoral) + Mesh Removal. (Specialist procedure).

Recurrence

• Rate: 1-2% for Mesh (Lichtenstein). 10-15% for Non-Mesh.
• Risk Factors: Infection, Smoking, Obesity, Technical failure (mesh too small).
• Management:
  • If primary was Open -> Do Laparoscopic (Approach virgin plane).
  • If primary was Lap -> Do Open.

The Inguinal Canal Walls (MALT)

• M uscles (Roof): Internal Oblique, Transversus Abdominis.
• A poneuroses (Anterior): External Oblique.
• L igaments (Floor): Inguinal (Poupart's), Lacunar (Gimbernat's).
• T ransversalis (Posterior): Transversalis Fascia.

Contents of the Cord

1. 3 Arteries: Testicular, Cremasteric, Artery to Vas.
2. 3 Nerves: Genitofemoral (Genital branch), Ilioinguinal (Outside cord!), Sympathetics.
3. 3 Others: Vas Deferens, Pampiniform Plexus, Lymphatics.
4. 3 Fascia: External Spermatic (from EO), Cremasteric (from IO), Internal Spermatic (from TF).

Return to Activity

• Walking: Immediately.
• Driving: When able to perform an emergency stop without pain (usually 1 week).
• Lifting: Avoid heavy lifting or straining (>10kg) for 4-6 weeks to allow mesh integration.
• Sex: When comfortable.

Landmark Trials

1. EU Hernia Trialists: Confirmed Mesh superior to Non-Mesh for recurrence.
2. IEHS Guidelines: TEP/TAPP recommended for bilateral/recurrent. Open for primary unilateral.
3. Watchful Waiting Trials: Confirmed safety for minimally symptomatic hernias in men (risk of strangulation extremely low, ~0.18% per year).

(As per original - restored)

What is an Inguinal Hernia?

An inguinal hernia is a bulge in the groin caused by part of the inside of your tummy (Usually fat or bowel) pushing through a weakness in the muscle wall.

What are the symptoms?

• A lump in the groin that may come and go, Get bigger when coughing or straining.
• Aching or discomfort.
• In men, the lump may extend into the scrotum.

Is it serious?

Most inguinal hernias are not immediately dangerous. However, if the hernia becomes trapped (Incarcerated) or the blood supply is cut off (Strangulated), it becomes an emergency and requires urgent surgery.

What is the treatment?

• Watchful waiting: If you have minimal symptoms, you may choose to monitor it.
• Surgery: The most common treatment. A mesh is placed to strengthen the muscle wall. This can be done as a keyhole (Laparoscopic) or open operation.

(As per original)

Common Exam Questions

1. Indirect vs Direct: "Difference?"
   • Answer: Indirect = Congenital, descends into scrotum, lateral to vessels. Direct = Acquired, through Hesselbach's, medial to vessels.
2. Hesselbach's Triangle: "Borders?"
   • Answer: Rectus (Medial), Inf Epigastric (Lateral), Inguinal Ligament (Inferior).
3. Nerves: "Which nerve is at risk in open repair?"
   • Answer: Ilioinguinal nerve.

Viva Points

• Triangle of Doom: Vascular danger zone in Lap repair.
• Triangle of Pain: Nerve danger zone in Lap repair.