What is the approach to examine and diagnose a scrotal (inguinal) hernia?

Approach to Examination and Diagnosis of Scrotal (Inguinal) Hernia

The most accurate approach to examining a scrotal hernia involves combining a thorough physical examination with the inguinal occlusion test and use of a handheld Doppler device to differentiate between direct and indirect inguinal hernias. 1

Physical Examination Technique

Initial Assessment

• Examine patient in both standing and supine positions
• Inspect for visible bulge or asymmetry in the groin or scrotum
• Ask patient to cough or perform Valsalva maneuver to elicit hernia

Key Examination Steps

1. Visual inspection:

   • Look for scrotal distortion or asymmetry
   • Note if hernia has descended into the scrotum causing any distortion (defining characteristic of scrotal hernia) 2

2. Palpation technique:

   • Place index finger at the external inguinal ring
   • Follow the inguinal canal upward toward the internal ring
   • Feel for a bulge or impulse during coughing/Valsalva maneuver
   • Determine if the hernia extends into the scrotum

3. Inguinal occlusion test with Doppler (highest accuracy):

   • Locate the epigastric vessels using a handheld Doppler device
   • Apply pressure over the internal ring while patient performs Valsalva
   • If bulge persists despite occlusion, it's likely a direct hernia (medial to epigastric vessels)
   • If bulge disappears with occlusion, it's likely an indirect hernia (lateral to epigastric vessels)
   • This combined approach has 79% accuracy for direct hernias and 93% accuracy for indirect hernias 1

4. Scrotal examination:

   • Determine if hernia can be reduced (important for management)
   • Assess for tenderness, suggesting possible incarceration
   • Evaluate for transillumination to differentiate from hydrocele
   • Note the extent of descent using proposed classification:
     • SI: upper third thigh
     • SII: middle thigh
     • SIII: lower third thigh or below 2

Diagnostic Imaging

When physical examination is inconclusive or additional information is needed:

Ultrasound (First-line imaging)

• Duplex Doppler ultrasound is the imaging modality of choice with high sensitivity and specificity 3, 4
• Can differentiate hernia from other scrotal pathologies (hydrocele, varicocele, testicular mass)
• Helps identify contents of hernia sac (omentum, bowel)
• Can assess for complications like strangulation

Advanced Imaging (When ultrasound is inconclusive)

• MRI provides superior soft tissue contrast and larger field of view 3
• Useful for complex cases or when ultrasound findings are equivocal
• Can better characterize hernia contents and complications
• CT may be useful for evaluating complications like bowel obstruction or strangulation 3

Differential Diagnosis

Important to differentiate scrotal hernia from other causes of scrotal swelling:

• Testicular torsion - acute onset of pain, abnormal testicular position, absent blood flow on Doppler 3
• Epididymitis - gradual onset of pain, tenderness over epididymis, increased blood flow on Doppler 3
• Hydrocele - transilluminates, no reducibility
• Varicocele - "bag of worms" feeling, increases with Valsalva, decreases when supine
• Testicular mass - firm, fixed mass within testis, may be painless 4
• Scrotal abscess - erythema, warmth, fluctuance
• Omental tumors - rare but can present as scrotal mass with inguinal hernia 5

Common Pitfalls to Avoid

• Failing to examine patient in both standing and supine positions
• Not having patient perform adequate Valsalva maneuver during examination
• Misdiagnosing other causes of scrotal swelling as hernia
• Overlooking signs of incarceration or strangulation (tenderness, erythema, irreducibility)
• Assuming all painless swelling is benign, potentially missing testicular tumors 4
• Not using Doppler to accurately differentiate between direct and indirect hernias 1

Management Considerations

• Irreducible scrotal hernias require urgent surgical evaluation
• Antibiotic prophylaxis is recommended for scrotal hernia repair despite weak evidence 2
• Urinary catheterization is recommended in complex cases (S2-3) due to prolonged operative time 2
• Laparoscopic repair (TAPP approach) has fewer conversions to open approach compared to TEP for scrotal hernias 2

By following this systematic approach to examination and diagnosis, clinicians can accurately identify scrotal hernias and differentiate them from other scrotal pathologies, leading to appropriate management decisions.