What is the diagnosis and treatment of an inguinal hernia?

Inguinal Hernia: Diagnosis and Management

The best way to diagnose an inguinal hernia is through a thorough physical examination, looking for a bulge or impulse in the groin area while the patient coughs or strains, with ultrasound or MRI reserved for uncertain cases. 1

Pathophysiology and Epidemiology

• Inguinal hernias result from incomplete involution of the processus vaginalis, creating a patent processus vaginalis (PPV) through which intra-abdominal structures like bowel can herniate 2
• The incidence is approximately 3-5% in term infants and 13% in infants born at less than 33 weeks gestational age 2
• More than 90% of pediatric inguinal hernias are diagnosed in boys, with 60% occurring on the right side 2
• The prevalence of PPV is highest during infancy (up to 80% in term male infants) and declines with age 2

Diagnostic Approach

Clinical Evaluation

• Patients often present with groin pain that may be burning, gurgling, or aching, with a heavy or dragging sensation that worsens with prolonged activity 1
• Physical examination should focus on identifying a bulge or impulse in the groin while the patient coughs or strains 1
• The abdominal bulge may disappear when the patient is in the prone position 1
• Physical examination alone has a sensitivity of 74.5% and specificity of 96.3% for detecting inguinal hernias 3

Imaging Studies

• Imaging is rarely warranted but may be helpful in specific situations 1:

  • Athletes without a palpable impulse or bulge
  • Recurrent hernias
  • Suspected hydroceles
  • Uncertain diagnosis
  • Surgical complications

• Ultrasound:

  • Has a sensitivity of 92.7% and specificity of 81.5% 3
  • Can identify the type of hernia (direct vs. indirect) with 85% accuracy 4
  • Can be performed by surgeons in an office setting 4
  • Particularly useful for evaluating groins without a palpable bulge (75% accuracy) 4

• MRI:

  • Has the highest diagnostic accuracy with sensitivity of 94.5% and specificity of 96.3% 3
  • Should include T1- and T2-weighted sequences as well as dynamic sequences 3
  • Most valuable in patients with clinically uncertain herniations 3

• Digital imaging by parents:

  • Can serve as an additional diagnostic aid in difficult cases, especially in children 5
  • Helps reduce the rate of negative groin explorations 5

Management Considerations

Indications for Repair

• All inguinal hernias in infants should be repaired to avoid the risk of bowel incarceration and gonadal infarction/atrophy 2
• All inguinal hernias in women should be operated on 6
• For asymptomatic inguinal hernias in adult males, surgery is not necessarily indicated 6

Surgical Approach

• For hernias in women and all bilateral hernias, a laparoscopic or endoscopic procedure is preferable 6
• Primary unilateral hernias in men can be treated either by open surgery or laparoscopy/endoscopy 6
• Patients treated by laparoscopy/endoscopy develop chronic pain less often than those treated by open surgery 6
• A mesh-based repair is generally recommended due to the pathogenesis involving abnormality of the extracellular matrix 6

Activity Restrictions Before Repair

• Patients should avoid activities that increase intra-abdominal pressure to prevent incarceration and strangulation 7
• The goal is to prevent complications that would necessitate emergency surgery with higher complication rates 7

Complications and Special Considerations

• Patients with suspected intestinal strangulation should undergo emergency hernia repair immediately 7
• Signs of systemic inflammatory response syndrome (SIRS) are common indicators of strangulated obstruction 7
• Delayed treatment (>24 hours) is associated with higher mortality rates 7
• Symptomatic periods lasting longer than 8 hours, presence of comorbid disease, high ASA scores, and presence of strangulation significantly affect morbidity rates 7
• Surgical complications and hernia recurrences are uncommon, but patients with recurrent hernias should be referred to the original surgeon if possible 1

Pitfalls in Diagnosis

• Early diagnosis of strangulated obstruction may be difficult by either clinical or laboratory means 7
• Physical examination alone may miss hernias that are not protruding at the time of examination 1
• The physical features of hernia (size of abdominal wall defect, amount of herniating intestine, ease of reduction) do not consistently predict the risk of incarceration 2