Inguinal Hernias

This comprises a protrusion of abdominal contents through the fascia of the abdominal wall, through the internal inguinal ring. Hernias always contain a portion of peritoneal sac and may contain viscera, usually small bowel and omentum.

Hernias comprise approximately 7% of all surgical outpatient visits.

• M:F 8:1
• Affects 1-3% of young children
• In men the incidence rises from 11 per 10,000 person years aged 16-24 years to 200 per 10,000 person years aged 75 years or above.¹

Risk factors

• In infants; prematurity, male sex
• In adults; male sex, obesity, constipation, chronic cough, heavy lifting

• Swelling in groin that may appear with lifting and be accompanied by sudden pain
• Indirect hernias are more prone to cause pain in scrotum and cause a 'dragging sensation'
• An impulse (increase in swelling) may be palpable on coughing
• May not be able to see the hernia if it is reduced
• If a lump is present, it may be reducible

Congenital inguinal hernias are usually detected at birth, and all need urgent outpatient referral for surgical repair.
Inguinal hernias in in older children and adults usually develop gradually, but can occur suddenly with episode of heavy lifting as 'rupture':

• At first appearance, hernia is usually easily reducible when patient reclines, but may require manual replacement if large.
• With time the hernia enlarges and becomes harder to replace, due to fibrous adhesions forming. When it can no longer be reduced, it is irreducible or incarcerated.

This can occur at any time, as can strangulation. This is when visceral contents of the hernia become twisted or entrapped by the narrow opening. This compromises the blood supply causing swelling, and eventually infarction.
Strangulation usually leads to bowel obstruction.

Assessment

• Examine patient both standing and lying and ask him to cough or strain.
• Insert finger through top of scrotum into external inguinal ring and palpate for lump when coughing - cough impulse.
• Sliding hernias are probable with large scrotal hernias.

See also "lumps in the groin and scrotum."

• Femoral hernia; these are seen in various forms, at simplest as a small swelling in the top of the inside of the thigh. Alternatively, it may be deflected to appear higher as an inguinal hernia. It is either irreducible or reduces only slowly with pressure.
• Hydrocoele (when differentiating from an inguinoscrotal hernia, note it is possible to get above a hydrocoele on examination
• Spermatic cord hydrocoele
• Lymph node swelling
• Abscess
• Saphena varix
• Varicocoele
• Bleeding
• Undescended testis

Ultrasound is the less invasive method, if there is doubt.
However, herniography with injection of X-ray contract agent into peritoneum is also used.
Alternatively, ultrasound can be useful.³

Adults

If the hernia is small, the patient may only need reassurance. However, there is always the chance of it becoming a surgical emergency through obstruction and incarceration. Episodes of pain and tenderness suggest need for urgent treatment, but when these become prolonged and severe then emergency surgery is indicated for possible strangulation.
The fundamentals of indirect inguinal hernia repair are the same regardless of the patient's age. Reduction or excision of the sac and closure of the defect with minimal tension are the essential steps in any hernia repair.

• Conventional surgery is based on Bassini's operation; this consists of apposition of the transversus abdominis and transversalis fascia and the lateral rectus sheath to the inguinal ligament. The Shouldice uses 2 layers of running suture in similar fashion.
• However, Lichtenstein technique is widely used where piece of open-weave polypropylene mesh is used to repair and reinforce the abdominal wall.⁴ This operation is easier to learn, gives earlier mobility and has a very low recurrence rate.^5,6 The standard repair now uses prostheses, usually polypropylene mesh. It is however, associated with a slightly increased risk of infection.⁷
• Laparoscopic repair is usually reserved for recurrences and bilateral hernias. There is less postoperative pain, full recovery is better, and return to work is faster.⁸ However, the price is increased compared to the conventional approach,⁹ and there appears to be a higher number of serious complications of visceral (especially bladder) and vascular injuries.⁸
• There are 2 approaches either the trans-abdominal pre-peritoneal (TAPP) or the totally extra-peritoneal (TEP) procedure. In TAPP the surgeon goes into the peritoneal cavity and places a mesh through a peritoneal incision over possible hernia sites. TEP is different as the peritoneal cavity is not entered and mesh is used to seal the hernia from outside the peritoneum. The mesh, where used, becomes incorporated by fibrous tissue.
• Surgery can be performed on a day case basis and for 7 days afterwards the patient should avoid driving and lifting. The patient should be able to resume normal activities over next 2-3 weeks, but can take up to 6 weeks to return to work with a heavy job.
• A truss may be required where surgery is inadvisable or refused, but however it can be difficult for the patients to manage and cannot be recommended as a definitive form of treatment.

Children

The incidence of incarcerated or strangulated hernias in paediatric patients is 10-20%. 50% of these occur in infants younger than 6 months:⁷

• Paediatric surgeons will repair soon after diagnosis, regardless of age or weight, in healthy full-term infant boys with asymptomatic reducible inguinal hernias.
• Premature infants with inguinal hernias are usually repaired prior to discharge from the neonatal intensive care unit (NICU), but this practice is changing, as infants are now being discharged home at much lower weights. Some surgeons prefer to postpone the surgery in these very small babies for 1-2 months to allow further growth.
• Herniotomy is all that is required with ligation and excision of the patent processus vaginalis.

These include:

• Recurrence; 0.5-1.0% - most happening within 5 years of operation. The recurrence rate increases in:
  • Children younger than 1 year
  • Elderly patients
  • After incarcerations
  • In those with ongoing increased intra-abdominal pressure
  • Growth failure
  • Prematurity
  • Chronic respiratory problems
  • In girls with sliding hernias
• Infarcted testis or ovary with atrophy
• Wound infection
• Bladder injury
• Intestinal injury
• A hydrocele from fluid accumulation in the distal sac usually resolves spontaneously but sometimes requires aspiration.

This is generally very good, depending on co-morbidity.