Groin hernias

A hernia is a protrusion of an organ through the wall that normally contains it
The wall can be the abdominal wall, muscle fascia, diaphragm or foramen magnum
Hernias can be congenital or acquired
Abdominal wall hernias are common
Account for approximately 10% of general surgical workload
The two main aetiological factors for acquired hernias are
- Increased intra-abdominal pressure (e.g. straining or lifting)
- Abdominal weakness (e.g. advancing age or malnutrition)
A hernia consists of:
- A sac
- Its coverings
- Its contents
Hernias can be:
- Reducible
- Irreducible
- Obstructed or incarcerated
- Strangulated
Irreducible hernias have either a narrow neck or the contents adhere to the sac wall
Obstructed hernias contain obstructed but viable intestine
Strangulated hernias when the venous drainage from the sac contents is compromised

Clinical features

Hernia usually present with a lump at an appropriate anatomical site
The hernia often increases in size on coughing or straining
It reduces in size or disappears when relaxed or supine
Examination may show it to have a cough impulse and to be reducible
Irreducible but non-obstructed hernias may cause little pain
If the hernia causes obstruction colicky abdominal pain, distension and vomiting may occur
The hernia will be tense tender and irreducible
If strangulation occurs the lump will become red and tender
Diagnosis is usually based on clinical features
Herniography may be useful in the investigation of chronic groin pain
Ultrasound or CT may be useful if a clinically occult hernia is suspected

Mortality of elective hernia repair

The mortality of elective hernia repair increases with age

< 60 yrs 0.1%

60 - 69 yrs 0.2%

70 - 79 yrs 1.6%

>80 yrs 3.3%

Mortality of strangulated hernia repair

10% patients with strangulation give no previous history of a hernia
The peak incidence of hernia strangulation is approximately 80 years
In those with acute onset of a hernia the greatest risk is in the first 3 months
Risk of strangulation depends on type of hernia
- Femoral is approximately 40%
- Direct inguinal is approximately 3%
The mortality of surgery for strangulated hernias has changed little over the past 50 years
Operative mortality remains at approximately 10%
Is ten times greater than that following an elective repair
Risk of death is dependent on:
- Age
- Presence of necrotic bowel requiring resection

Picture provided by Maurice McCreary, Greater South East Community Hospital, Washington, USA

Inguinal hernias

80,000 operations per year in UK
3% adults will require operation for inguinal hernia
Male : female ratio is 12:1
Elective : emergency operation 12:1
Peak incidence is in the 6th decade
65% inguinal hernias are indirect
In females inguinal hernias are as common as femoral hernias

Anatomy

Inguinal canal lies between the superficial and deep inguinal rings
Deep ring lies deep to the mid-inguinal point
Mid-inguinal point is half way between symphysis pubis and anterior superior iliac spine
Not the midpoint of the inguinal ligament
In men it contains vas deferens and testicular artery and veins
In women it contains the round ligament
Anterior border is the external oblique aponeurosis
Posterior border is the transversalis fascia
Inferior border is the inguinal ligament
Superior border is the conjoint tendon - the lower fibres of internal oblique and transversus abdominis
Indirect hernias arise lateral to the inferior epigastric vessels
Direct hernias arise medial to the inferior epigastric vessels

Classification of inguinal hernias (Nyhus)

Type 1 Indirect hernia with normal internal ring

Type 2 Indirect hernia with dilated internal ring. Posterior wall intact

Type 3 Posterior wall defect

A Direct inguinal hernia

B Indirect inguinal hernia. Internal ring dilated. Posterior wall defective

C Femoral hernia

Type 4 Recurrent hernia

Techniques of inguinal hernia repair

Herniotomy involves removal of the sac and closure of the neck
Herniorrhaphy involves a form of reconstruction to
- Restore the disturbed anatomy
- Increase the strength of the abdominal wall
- Construct a barrier to recurrence
Herniorrhaphy can be achieved with following techniques
- Bassini +/- Tanner Slide
- Darn
- Shouldice
- Lichtenstein
- Other Mesh - Stoppa
- Laparoscopic
Shouldice or Liechtenstein now regarded as 'gold standard' as judged by low risk of recurrence
Laparoscopic hernia repair should be reserved for bilateral or recurrent hernia

Complications of hernia repairs

Urinary retention
Scrotal haematoma
Damage to the ileoinguinal nerve
Ischaemic orchitis
Recurrent hernia

Trusses

40,000 sold annually in UK
20% purchased prior to seeing a doctor
45% have no instruction on fitting
75% fit whilst standing up!

Recurrent inguinal hernia

Recurrence rate varies with herniorrhaphy technique and duration of follow up
With Bassini and darn repairs may be as high as 20%
With Shouldice and Lichtenstein repairs recurrence rates <1% have been reported
Factor involved in recurrence include:
- Inadequate preoperative selection
- Type of hernia
- Type of operation
- Postoperative wound infection
Recurrent hernias should be repaired using a mesh technique
Can be performed as either an open or a laparoscopic procedure
Patients should be consented for a possible orchidectomy

Femoral hernias

Account for 7% of all abdominal wall hernia
Female : male ratio is 4:1
Commonest in middle aged and elderly women
Rare in children
More common in parous
Much less common than inguinal hernias but are as common as inguinal hernias in older women

Anatomy of the femoral canal

Anterior border is the inguinal ligament
Posterior border is the pectineal ligament
Medial border is the lacunar ligament
Lateral border is the femoral vein

Differentiation between inguinal and femoral hernias

Inguinal hernia Femoral hernia

Femoral hernia Inguinal hernia

Vaginal hydrocele Lymphadenopathy

Hydrocele of the cord Saphena varix

Undescended testis Ectopic testis

Lipoma of the cord Psoas abscess

Psoas bursa

Lipoma

Management of femoral hernia

All uncomplicated femoral hernias should be repaired as an urgent elective procedure
Three classical approaches to the femoral canal have been described
- Low (Lockwood)
- Transinguinal (Lotheissen)
- High (McEvedy)
Irrespective of approach used the following will be achieved
- Dissection of the sac
- Reduction / inspection of the contents
- Ligation of the sac
- Approximation of the inguinal and pectineal ligaments

Special types of hernia

Richter's hernia
- Partial enterocele
- presents with strangulation and obstruction
Maydl's hernia
- W loop strangulation
- Strangulated bowel within abdominal cavity
Littre's hernia
- Strangulated Meckel's diverticulum
- Can cause small bowel fistula

Bibliography

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EU Trialists Collaboration. Repair of groin hernias with synthetic mesh: meta analysis of randomised controlled trials. Ann Surg 2002; 235: 322-332.

Jones A Thomas P. Decision Making in surgery: How should an inguinal hernia be repaired. Br J Hosp Med 1995; 54: 391 - 393.

Kingsnorth A N. Modern hernia management. In: eds. Taylor I Johnson C D Recent Advances in surgery 18. Churchill Livingston 1995. 159 - 178.

Kingsnorth A N. Inguinal hernia repair. Current Practice in Surgery 1993; 5: 202 - 206.

Kingsnorth A N, LeBlanc K. Hernias: inguinal and incisional. Lancet 2003; 362: 1562-1571.

Macintyre I M C. Laparoscopic hernia repair. Current Practice in Surgery 1995; 7: 39 - 42.

Macintyre I M C. Best practice in groin hernia repair. Br J Surg 2003; 90: 131-132.

Memon M A, Cooper N J, Memon B et al. Meta-analysis of randomised clinical trials comparing open and laparoscopic inguinal hernia repair. Br J Surg 2003: 90: 1479-1492.

Schumpelick V. Inguinal hernia repair in adults. Lancet 1994; 344: 375 - 378.

Thomas P. Decision making in surgery: Operative management of a strangulated femoral hernia. Br J Hosp Med 1993; 49 : 432 – 433.

Working Party of the Royal College of Surgeons. Clinical guidelines on the management of groin hernias in adults. RCS London 1993.