Indirect Inguinal Hernia

An indirect inguinal hernia enters the inguinal canal through the deep inguinal ring lateral to the inferior epigastric vessels.

The sac follows the course of the spermatic cord in men or round ligament in women and may traverse the superficial ring into the scrotum or labium.

Persistence of the processus vaginalis provides the anatomical basis for congenital indirect hernias, although many become clinically apparent only in adulthood.

A complete indirect hernia extends into the scrotum. An incomplete hernia remains within the inguinal canal.

The swelling usually begins in the groin and may extend toward the scrotum.

It increases with coughing or straining and often reduces when supine.

Large indirect hernias may produce a dragging sensation, discomfort during activity or difficulty with manual reduction.

Acute pain with irreducibility, vomiting or abdominal distension indicates acute incarceration or strangulation.

A groin swelling should not be labelled indirect based purely on examination because clinical differentiation from a direct hernia is imperfect.

The repair principles are the same as for other adult inguinal hernias.

Symptomatic disease should undergo elective repair.

A minimally invasive posterior repair places mesh across the entire myopectineal orifice rather than simply treating the visible indirect defect.

During TEP or TAPP repair, reduce the indirect sac from the cord structures while protecting the vas deferens and gonadal vessels. A large distal scrotal sac does not always need complete excision if aggressive dissection risks cord injury. The proximal sac must be adequately managed.

During open repair, identify the sac anteromedial to the cord structures, separate it carefully and perform a flat mesh repair of the posterior inguinal floor.

The deep ring may be relatively large, but narrowing it excessively risks injury or constriction of the cord.

Emergency operation is required for suspected strangulation or failed reduction of an acutely irreducible hernia. The bowel within an indirect sac can become compromised rapidly when the neck is narrow.

Internal Hernia

An internal hernia is protrusion of bowel through a congenital or acquired intraperitoneal or mesenteric aperture while remaining within the abdominal cavity.

Major types include paraduodenal, transmesenteric, transomental, pericaecal, sigmoid mesocolon, foramen of Winslow and postoperative internal hernias.

Acquired mesenteric defects are particularly important after Roux en Y gastric bypass, bowel reconstruction and transplantation.

Internal hernias frequently create a closed loop obstruction, making strangulation and bowel infarction the major concern.

Presentation ranges from intermittent spontaneously resolving abdominal pain to complete bowel obstruction with strangulation.

Patients may report recurrent episodes of central or upper abdominal pain, often associated with nausea and vomiting.

Acute closed loop obstruction produces severe pain, vomiting and progressive abdominal tenderness.

Persistent pain, tachycardia, focal guarding, gastrointestinal bleeding, metabolic deterioration or peritonism suggests bowel ischaemia.

A history of previous gastric bypass or complex bowel reconstruction should markedly increase suspicion even when the examination is initially mild.

CT abdomen and pelvis with IV contrast: investigation of choice; look for clustered displaced bowel loops with convergence or twisting of mesenteric vessels at an abnormal internal aperture and determine whether a closed loop is present.

A negative CT does not completely exclude an intermittent postoperative internal hernia. Recurrent severe symptoms after Roux en Y reconstruction require a low threshold for surgical assessment.

An internal hernia causing acute obstruction requires early operative management because deterioration from obstruction to strangulation can be rapid.

Keep fasting, establish IV access, correct fluid and electrolyte deficits and use nasogastric decompression when significant vomiting or distension is present.

Do not undertake a prolonged conservative trial when CT demonstrates an internal hernia with a closed loop or when clinical suspicion for strangulation is high.

Laparoscopy is appropriate in stable patients with manageable bowel distension. Laparotomy is preferable when there is haemodynamic instability, massive distension, established peritonitis or anticipated extensive bowel resection.

At operation:

Reduce the herniated bowel carefully
Assess the entire involved segment for viability
Identify the anatomical defect
Close the defect securely
Resect irreversibly ischaemic bowel

All relevant mesenteric defects should be inspected in patients with previous reconstructive surgery because more than one potential internal aperture may exist.

If bowel viability is uncertain after reduction, allow time for reperfusion and reassess. Extensive questionable bowel should not be unnecessarily resected. A planned second look operation may be appropriate when viability remains uncertain.

If ischaemic or perforated bowel is present, begin enteric Gram negative and anaerobic coverage, for example:

Ceftriaxone 2 g IV every 24 hours plus metronidazole 500 mg IV every 12 hours.

Severe sepsis or extensive contamination can be treated with:

Piperacillin tazobactam 4.5 g IV every 8 hours by extended infusion, adjusted for renal function.

Indirect Inguinal Hernia

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management