A 58-year-old man is referred to the surgical outpatient clinic with a small, asymptomatic bulge below the inguinal ligament in the right groin. On clinical examination, the mass is soft, compressible, and located medial to the femoral pulse. The diagnosis of femoral hernia is suspected. What is the most appropriate investigation to confirm the diagnosis in this asymptomatic patient?

Explanation

## Investigation of Choice for Asymptomatic Femoral Hernia ### Tailoring Investigation to Clinical Presentation **Key Point:** In an **asymptomatic** patient with suspected femoral hernia, high-resolution ultrasound with dynamic maneuvers (Valsalva) is the most appropriate first-line investigation—it is non-invasive, cost-effective, and avoids unnecessary radiation. **Clinical Pearl:** The key distinction is **symptom status**. Asymptomatic hernias do not require urgent CT; ultrasound with dynamic imaging is sufficient for diagnostic confirmation and surgical planning. **High-Yield:** Ultrasound advantages in asymptomatic cases: - No radiation exposure - Real-time visualization of hernia sac and contents - Dynamic assessment (Valsalva increases intra-abdominal pressure, making hernia more apparent) - Differentiation from lymph nodes, cysts, or other masses - Excellent for determining reducibility - Can be repeated without risk ### Investigation Selection by Clinical Context | Clinical Scenario | Investigation of Choice | Rationale | |---|---|---| | **Asymptomatic, uncomplicated** | Ultrasound + Valsalva | Non-invasive, cost-effective, no radiation | | **Tender, irreducible, signs of obstruction** | CT with IV contrast | Assess viability, obstruction, urgency | | **Recurrent hernia, complex anatomy** | MRI or CT | Better soft-tissue definition | | **Acute presentation with obstruction** | CT (STAT) | Rapid assessment of complications | ### Why Ultrasound is Sufficient Here 1. **No acute symptoms** → No need for IV contrast or rapid assessment 2. **Diagnostic confirmation only** → Ultrasound sensitivity is 70–85%, adequate for asymptomatic cases 3. **Cost and radiation** → Ultrasound avoids both 4. **Dynamic assessment** → Valsalva maneuver increases sensitivity by making the hernia more obvious **Mnemonic: DUVS** — Dynamic Ultrasound Valsalva Sensitivity (for asymptomatic hernias). [cite:Bailey & Love's Short Practice of Surgery 28e Ch 31]