Inguinal Hernia

» General Surgery

Overview

Overview Higher incidence among men 40 to 59 years of age. Although there are many different types of hernias, they are usually related to the abdomen, with approximately 75% of all hernias occurring in the inguinal region. Hernia contains omentum (90% of cases) or intestine (10% of cases). Inguinal hernias are at risk of irreducibility or incarceration, which may result in strangulation and obstruction. However, femoral hernias are much more likely to strangulate compared to inguinal because of the narrowed femoral ring.

Definition
Hernia: A bulge or protrusion of an organ or tissue through an abnormal opening within the anatomic structure that normally confines it.
Inguinal Hernia:
Reducible: Refers to a hernia that can be moved back into place easily (either manually or spontaneously)
Irreducible: Refers to a hernia that CANNOT be moved back into place, remains budged. Irreducible hernia can lead to a incarcerated, obstructed or strangulated hernia.Incarcerated: Refers to a hernia that cannot be pushed back. It does not necessarily mean that the hernia is strangulated or that obstruction is occurring (although both are possible). If spontaneously reduced, and patient feels better.
Obstructed hernia: gut hernia causing incarceration (momentum hernia does not cause incarceration because gut flow is normal)
Strangulated hernia: compression of blood flow to the strangulated bowel leading to necrosis

Side note The composition of a hernia is 1. the sac, 2. the covering of the sac 3. the content of the sac.

Video: Introduction to Inguinal Hernia

Anatomy of the Abdominal Wall

"No disease of the human body, belonging to the province of the surgeon, requires in its treatment a better combination of accurate anatomical knowledge with surgical skill than Hernia in all its varieties" Astley Cooper (1804)

Inguinal Hernia Anatomy

The inguinal canal is the oblique passage through the lower abdominal wall. It runs from deep to superficial, from internal to external inguinal rings. The testis follows this canal and into the scrotum during development, and therefore the spermatic cord runs through this canal.

Superficial (external) inguinal ring is a V-shaped defect in the external oblique aponeurosis.
Deep (internal) inguinal ring is formed through the transversalis fascia. It is located above the mid point of the inguinal ligament.

The deep and superficial ring should close normally

Mid-inguinal point (between the ASIS and pubic symphysis): Femoral artery

Mid point of the inguinal point (between the ASIS and pubic tubercle): deep ring of the inguinal canal

Borders of the Inguinal Canal

Posterior (deep ring): Transversalis fascia
Anterior (superficial ring): External oblique aponeurosis (not muscle)
Floor: Inguinal ligament
Roof: (conjoint tendon?)/Transversalis Fascia, Internal oblique

Contents of the Inguinal Canal (rule of 3s)

Artery: Cremastric, testicular, vas deferens
Others: Spermatic cord (vas deferens), Pampinform plexus, lymphatics
Nerve: Genital branch of the genitofemoral nerve, sympathetic nerve, ilioinguinal nerve
Layers: (Processus vaginalis) + Internal spermatic fascia, cremastic muscle, external spermatic fascia

Remember in females the content of the inguinal canal is four things: Round ligament, genital branch of the genitofemoral nerve, lymphatics and sympathetic plexus.

Borders of the Hesselbach Triangle

Inferiorly: Inguinal ligament (Iliopubic tract labroscopically)
Laterally: Inferior epigastric artery
Medially: lateral border of rectus muscle

Types of Inguinal Hernia

	Indirect Inguinal	Direct Inguinal	Femoral
Definition	Intestine passes through deep inguinal ring	Intestine passes through weak abdominal wall	Intestine passes through weak femoral ring
Age	Any age but usually young	Acquired weakness in abdominal wall	More common in women, due to their wider bony pelvis
Aetiology	Congenital (patent process vaginalis)	Acquired	Acquired
Relationship to inferior epigastric artery	Lateral	Medial	An aberrant obturator artery of the inferior epigastric arery ,ay cross the lacunar ligament
Descending to scrotum	Often	Rarely	-
Occluding the internal ring	Controls it	Does not control it	-
Neck	Narrow	Wide	Narrow
Strangulation	More likely	Rare	Much more likely
Treatment	Infant - herniotomy, Adults - open/laparoscopic mesh	Open/laparoscopic mesh	Laparoscopic mesh

Risk Factors

Family history
Personal history
Smoking
Increasing age — the lifetime risk of a man aged 25 developing an inguinal hernia is one in five. At age 65 it is two in five
Systemic disease processes such as cirrhosis, renal failure, scurvy or malnutrition
Raised intra-abdominal pressure, such as occurs with pregnancy, ascites or obesity
Straining, such as chronic cough, prostatism or chronic constipation.

Signs and Symptoms

The diagnosis of an inguinal hernia is usually made through history and physical examination findings. Patients can either be asymptomatic or symptomatic

Asymptomatic with a bulge

Symptomatic with a buldge- Gradually or suddenly

Groin pain
Burning
Gurgling
Aching sensation in the groin
Heavy or dragging sensation may worsen toward the end of the day and after prolonged activity.
An abdominal bulge may disappear when the patient is in the prone position

Examination

Examine the patient first when he or she is standing
Demonstrate lump with:
- Valsalva maneuvers → may worsen pain
- Cough impulse → cause more abdominal contents to be pushed through the hernia defect → larger hernia
Then do an abdominal examination with the patient lying down
No merit in trying to differentiate between direct and indirect hernias
Remember differential diagnosis

Remember Hernias may be easily diagnosed with an adequate physical examination.

Side note Bilateral inguinal hernias are extremely common, as is clinically evident connective tissue weakness in both groins. Any patient presenting with an inguinal hernia should have the contralateral groin examined when lying flat.

Red Flag Triad: Irreducible, Absent cough impulse, Pain

Differential Diagnosis

DIFFERENTIAL DIAGNOSIS OF SCROTAL/GROIN LUMP
Condition	Clinical features
Ectopic testis	Absence of a testis in the scrotum
Epididymitis	Severe pain surrounding the testis, tenderness, fever, chills
Femoral adenitis/adenopathy	Bilateral, firm, tender nodes; fever
Femoral arterial aneurysm	Older patient, pulsatile mass, no systemic symptoms
Femoral hernia	More common in women, often incarcerated, bowel obstruction
Hematoma	Associated trauma, ecchymoses, tenderness, no change with Valsalva maneuver
Hidradenitis	Draining abscesses in intertriginous skin of the groin
Hydrocele	Mass in the scrotum or inguinal canal that transilluminates
Inguinal adenitis/adenopathy	Tenderness, redness possible, often bilateral, systemic symptoms
Inguinal hernia	Bulge or impulse detected in inguinal canal with Valsalva maneuver or coughing
Lymphoma	Firm, tender mass; may increase in size; organomegaly; systemic symptoms
Lipoma	Soft, asymptomatic mass; does not change in size

Investigations

Hernia is a clinical diagnosis and should be referred to a surgeon. Ultrasound does not change management and so is unnecessary.
The surgeon can order imaging if necessary prior to surgery when the diagnosis is uncertain

Aetiology

Hernia occur at sites of weakness in the wall. This weakness may be:

Normal (physiological weakness, related to the anatomical causes - due to increased intrabdominal pressure
Congenital abnormality
Acquired - either traumatic and diseased

In terms of inguinal herniae:

Neonatal and infantile inguinal hernia - Pathological failure of obliteration of the embryological processus vaginalis at birth
Adult inguinal hernia - pathological change in collagen. A wide body of evidence continues to accumulate regarding defective collagen as the main factor.

Management

Non-Surgical Treatment

Watchful waiting, althought surgery is advised incase of future complications associated with hernia such as strangulation or incarceration

Surgical Treatment (recommended)

Open or larproscopic - depending on clinical situation and patient comorbidity
Mesh or suture repair - mesh better prognostically
Local or general anaesthetics

LAPROSCOPIC SURGERY
Advantages	Disadvantages
Quicker recovery time than open repair — usually about half the time to activity.	Rarely, unrecognised bowel perforation caused by balloon inflation has occurred when dense adhesions after peritonitis have tethered the bowel
Less postoperative pain has been shown in several series	More expensive than open repair
Less chronic groin pain — the surgery takes place behind the muscles, so no nerves are likely to be damaged	Future prostate cancer surgery is very difficult for the urologist, as the pre-peritoneal space anterior to the bladder is obliterated
Less risk of damage to the testicular blood supply	A general anaesthetic is always required