Hernia examinations commonly arise in OCSE's. You may be asked to examine a patient for a hernia directly, at the end of an abdominal examination, or during a groin examination. This article will focus on inguinal hernias.
Hernia: “A hernia is a protrusion of whole or part of a viscus, from its normal position, through an opening in the wall of its containing cavity.” [i]
Types of hernias
There are several different classifications of hernias.
Inguinal hernia - A hernia that is located above and medial to the pubic tubercle. They can be either direct or indirect.
- Direct inguinal hernia - A hernia that arises from a defect in the posterior wall of the inguinal canal and then passes through the superficial inguinal ring. They are more common in elderly patients.
- Indirect inguinal hernia - A hernia that passes through the deep inguinal ring, along the inguinal canal and out through the superficial inguinal ring. It may extend down into the scrotum. “Indirect hernias compromise 85% of all hernias and are more common in younger men.”[ii]
Femoral hernia - A hernia that is inferior and lateral to the pubic tubercle. They are firmer than inguinal hernias and are more common in women. They are also more prone to obstruction and strangulation than inguinal hernias due to the narrow neck of the femoral ring.
Incisional hernia - A hernia that develops along the scar tissue of a surgical incision.
Other types of hernias include umbilical, paraumbilical and epigastric.
Anatomy of the Inguinal region
In order to fully understand the examination, it is essential to be familiar with the anatomy of the inguinal region. Important surface landmarks that are commonly confused include:
The mid-inguinal point: Found half-way between the Anterior Superior Iliac Spine (ASIS) and Pubic Symphysis (PS). This marks the point where the femoral pulse can be palpated.
The mid-point of the inguinal ligament: Found half-way between the ASIS and Pubic Tubercle (PT). This landmark signifies where the deep (internal) inguinal ring lies. This can help to determine whether the hernia is direct or indirect, whilst carrying out a clinical examination.
The superficial (external) inguinal ring is the end of the inguinal canal. It lies superior and medially to the pubic tubercle.
The inguinal canal contains the spermatic cord in males and the round ligament in females. It also contains the ilioinguinal nerve in both males and females.
It is important to be able to describe the borders of the inguinal canal as it is a common question that may be asked at the end of the examination.
- The floor of the canal is formed by the inguinal ligament and the lacunar ligament medially.
- The roof is formed from the fibres of the transversus abdominis and internal oblique muscles.
- The anterior wall is formed by the external oblique muscles.
- The posterior border is formed by the transversalis fascia laterally and the conjoined tendon along its medial one third.
1. Wash your hands
- Make sure the examiner observes you washing your hands; alcohol hand gel will normally be provided.
2. Introduce, Consent, Expose (ICE) and Position
- Always introduce yourself to the patient and ask for consent to carry out the examination, briefly describing what the examination will involve.
- For the examination the patient should ideally be exposed from ‘nipple to knee’ i.e. the abdomen, groin area and external genitalia should be fully exposed. (To help maintain the patient’s dignity they can keep their underwear on until you need to inspect the area). The examiner will indicate if they only want you to expose a certain area of the patient.
- Before starting the examination, ask the patient if they have any pain in the abdomen or groin region.
- The patient will be lying down or sitting at the beginning of the examination. Ideally the patient should be standing up and you kneeling by their side (although this may not be possible for elderly patients). This will accentuate any hernias.
- Carry out a general inspection of the patient and bedside.
- If there are any visible lumps or swelling you should describe them like any other lumps; describe the site, size and shape. You should also note any colour or skin changes around the lump and if it extends into the scrotum.
- Always examine both sides of the groin, comparing sides if you are unsure the patient has a lump/swelling.
- Palpation is an important part of the examination because it may allow you to determine whether a lump is a hernia or another type of groin lump e.g. a hydrocele. It should be carried out with one hand over the lump, with the other supports the patient.
- On palpation, if you are able to get above the lump, it is unlikely to be a hernia i.e. you normally cannot palpate above the upper border of a hernia.
- During palpation you should continue your assessment of the lump. Describe the consistency, temperature, and surface of the lump. Is it tender? It is fluctuant?
- Check for a cough impulse by placing your hand firmly over the lump and asking the patient to cough. If a hernia is present, the area will expand and become tense.
- It is important to assess whether a hernia is reducible or irreducible. Reducible: the hernia can be returned to its normal anatomical site i.e. it can be pushed back into the abdomen. Irreducible: the hernia cannot be reduced i.e. it cannot be pushed back into the abdomen. Irreducible hernias are more prone to obstruction. If the patient indicates they have a reducible hernia, ask them to reduce it themselves since it may be painful. If you have to reduce a hernia you should push it in slowly with the palm of your hand. A lump that can be reduced strongly suggests a hernia.
- It is more difficult to determine clinically whether the hernia is a direct or indirect inguinal hernia. You may be asked to define the terms at the end of the examination.
- Once the lump has been reduced place your fingers firmly over the deep inguinal ring (see above) and ask the patient to cough. If it remains reduced it is likely to be a direct hernia. If the hernia reappears then it is an indirect hernia.
5. Percussion and Auscultation
- A resonant hernia is more likely to contain loops of bowel.
- You should auscultate over the hernia for bowel sounds. These are associated with a higher risk of complications.
6. You should repeat the examination on the contralateral side of the groin and carry out a full scrotal and abdominal examination. The examiner will tell you whether or not to carry out these examinations.
To finish, thank the patient and cover them up, wash your hands and then present your findings to the examiner.
The two most important complications are obstruction and strangulation. A hernia is normally surgically repaired to prevent these complications from occurring.
- Obstruction: “Constriction at the neck of a hernial sac leading to obstruction of the loops of bowel within it.”[iii]
- Strangulation: “Constriction prevents venous return causing venous congestion, arterial occlusion and gangrene. This may lead to perforation causing peritonitis.”[iv] This is a surgical emergency and requires urgent repair to prevent fatal consequences.
[i] Kuperberg G, Lumley J. Surgical Finals: Passing the Clinical. 2nd Ed. Cheshire: PasTest Ltd; 2009
[ii] Douglas G, Nicol F, Robertson C. Macleod’s Clinical Examination.12th Ed. London. Churchill Livingstone. 2009
[iii] Kuperberg G, Lumley J. Surgical Finals: Passing the Clinical. 2nd Ed. Cheshire: PasTest Ltd; 2009
[iv] Kuperberg G, Lumley J. Surgical Finals: Passing the Clinical. 2nd Ed. Cheshire: PasTest Ltd; 2009