Inguinal Hernia Flashcards
What is a hernia?
A hernia is defined as the protrusion of part or whole of an organ or tissue through the wall of the cavity that normally contains it.
What is the most common type of abdominal wall hernia?
Inguinal hernias are the most common type of hernia and account for around 75% of all anterior abdominal wall hernias, with a prevalence of 4% in those over 45 years.
What are the 2 subtypes of inguinal hernia?
Direct (20%) and indirect (80%).
Briefly describe direct inguinal hernias
Bowel enters the inguinal canal “directly” through a weakness in the posterior wall of the canal, termed Hesselbach’s triangle.
They occur more commonly in older patients, often secondary to abdominal wall laxity or a significant increase in intra-abdominal pressure.
Briefly describe indirect inguinal hernias
Bowel enters the inguinal canal via the deep inguinal ring.
They arise from incomplete closure of the processus vaginalis, an outpouching of peritoneum allowing for embryonic testicular descent, therefore are usually deemed congenital in origin.
With regards to the inferior epigastric vessels, how do direct and indirect hernias differ?
These two types of inguinal hernia can only be reliably differentiated at the time of surgery by identifying the inferior epigastric vessels indirect hernias will be lateral to the vessels whilst direct hernias will be medial to the vessels.
What are the risk factors for an inguinal hernia?
- Male
- Increasing age
- Raised intra-abdominal pressure, from chronic cough, heavy lifting, or chronic constipation
- Obesity
What are the clinical features of an inguinal hernia?
The most common presenting symptom is a lump in the groin, which (for reducible hernia) will initially disappear with minimal pressure or when the patient lies down. There may be mild to moderate discomfort which can worsen with activity or standing.
If the hernia becomes incarcerated, it can become painful, tender and erythematous. The patient may also present with clinical features of bowel obstruction if the bowel lumen becomes blocked, or with features of strangulation if the blood supply becomes compromised.
How does a strangulated hernia present?
A hernia that has strangulated will present as an irreducible and tender tense lump, with the pain often being out of proportion to clinical signs; this may be accompanied with clinical features of obstruction.
When examining a suspected hernia, what specific features should be noted?
When examining any groin lump, specific features to note for any suspected inguinal hernia include:
- Cough impulse- remember that an irreducible hernia may not have a cough impulse
- Location- inguinal (superomedial to the pubic tubercle) or femoral (inferolateral to the pubic tubercle)*rotum, can you get above it / is it separate from the testis
- Reducible- on lying down +/- minimal pressure
- If it enters the sac
Theoretically, on examination, how can a direct and indirect inguinal hernia differ?
Theoretically, to differentiate a direct from an indirect inguinal hernia, the examiner must reduce the hernia and then place pressure over the deep inguinal ring (located at the mid-point of the inguinal ligament), before asking the patient to cough.
If the hernia protrudes despite occlusion of the deep inguinal ring, this indicates a direct hernia, whereas if the hernia does not protrude, this indicates an indirect hernia.
However, this assessment is often seen as unreliable and the only definite method to differentiate them is at the time of surgery.
What investigations should be ordered for an inguinal hernia?
A hernia is typically a clinical diagnosis. Current Royal College of Surgeons Guidelines state that imaging should only be considered in patients if there is diagnostic uncertainty or to exclude other pathology.
If necessary, an ultrasound scan is recommended as first line imaging in the outpatient setting. For patients with features of obstruction or strangulation, CT imaging will be required.
Briefly describe the conservative management of an inguinal hernia
Any patient with a symptomatic inguinal hernia (significant mass or discomfort) should be offered surgical intervention.
The risk of strangulation is approximately 3% per year with an inguinal hernia. Any patients presenting with evidence of strangulation (such as pain out of proportion to clinical features or deranged biochemical results) nearly always require urgent surgical exploration.
A third of patients with an inguinal hernia will never experience any symptoms and most of these patients can be managed conservatively, however discussion should take place around the likelihood of future surgical intervention and the symptoms of potential strangulation.
What are the 2 different surgical options for an inguinal hernia?
Hernia repairs can be performed via open repair (Lichtenstein technique most commonly used) or laparoscopic repair (either total extraperitoneal (TEP) or transabdominal pre-peritoneal (TAPP)).
Briefly describe the use of open mesh repair
Open mesh repairs are preferred for those with primary inguinal hernias and are deemed the most cost-effective technique in this patient group.
They can be performed under general, spinal or local anaesthesia, dependent on patient fitness and surgeon preference.
Briefly describe the treatment algorithm for inguinal hernias
