Define Strangulated Hernia. Describe its pathophysiology, clinical features and management.

The Concept

A strangulated hernia is one in which the blood supply to the contents of the sac is cut off, and it is the most feared complication of any hernia — a surgical emergency. Without prompt relief, the trapped bowel proceeds through ischaemia → gangrene → perforation → peritonitis, which is life-threatening.

Pathophysiology

The mechanism is sequential and worth stating. The tight neck of the sac first obstructs the low-pressure venous and lymphatic return, so the contents become congested and oedematous; this swelling further tightens the neck until the arterial supply is occluded, producing ischaemia and, if unrelieved, infarction (gangrene). Femoral and indirect inguinal hernias, with their narrow necks, strangulate most readily.

Clinical Features

The hernia becomes suddenly painful, tense, tender and irreducible, with an absent cough impulse and often redness of the overlying skin. There are usually accompanying features of intestinal obstruction (colicky pain, vomiting, distension) and, as ischaemia advances, systemic toxicity — tachycardia, fever and signs of sepsis.

Management

Treatment is emergency surgery: resuscitate the patient (fluids, analgesia, nasogastric tube, antibiotics), then explore the hernia, assess the viability of the contents, resect any non-viable bowel, and repair the defect. A cardinal rule is to never forcibly reduce a strangulated hernia — doing so can push dead bowel back into the abdomen ('reduction en masse'), converting a localised problem into fatal peritonitis.

Examine the Groins in Obstruction

A recurring clinical lesson is that a small, easily-missed hernia — especially a femoral hernia in an obese elderly patient — is a classic cause of unexplained intestinal obstruction. Therefore the groins and hernial orifices must always be examined in any patient presenting with intestinal obstruction. Overlooking a strangulated femoral hernia hidden in the groin folds is a well-recognised and avoidable error.

The Bottom Line

A strangulated hernia is a surgical emergency of compromised blood supply — painful, tense, tender, irreducible, no cough impulse — treated by resuscitation and emergency surgery, and never by forcible reduction.

A Note on Taxis

The only situation in which gentle reduction ('taxis') may be attempted is an obstructed but not yet strangulated hernia of recent onset, performed gently and once only; forceful or repeated attempts are dangerous and any suspicion of strangulation (tenderness, redness, toxicity, or a long history) is an absolute contraindication. When in doubt, the safe course is surgical exploration rather than attempted reduction.

Tense, tender, irreducible with absent cough impulse.

• Strangulated hernia = blood supply to contents cut off → ischaemia → gangrene → perforation/peritonitis (emergency).
• Mechanism: tight neck obstructs venous return → oedema → arterial occlusion → infarction; femoral & indirect inguinal strangulate most.
• Sudden painful, tense, tender, irreducible hernia, no cough impulse, overlying redness, features of obstruction + toxicity.
• Emergency surgery: resuscitate → explore, assess viability, resect non-viable bowel, repair.
• Never forcibly reduce (reduction en masse); examine groins in any bowel obstruction.