A 72-year-old woman with a 10-year history of asymptomatic right femoral hernia presents with sudden onset colicky lower abdominal pain and vomiting for 8 hours. On examination, she is afebrile (37.1°C), blood pressure 115/72 mmHg, heart rate 98/min. The femoral hernia is palpable but not visibly prominent; it is tender and irreducible. Abdominal examination shows mild distension with active bowel sounds. Laboratory tests: WBC 11,200/µL, serum lactate 1.8 mmol/L, creatinine 1.2 mg/dL. Abdominal X-ray shows small bowel obstruction pattern. What is the most appropriate next step?

Explanation

## Clinical Diagnosis: Incarcerated Femoral Hernia with Acute Small Bowel Obstruction — Urgent Surgical Exploration **Key Point:** An **irreducible (incarcerated) femoral hernia** causing **acute small bowel obstruction** is a surgical emergency. Femoral hernias carry the highest risk of strangulation among all hernias (up to 40%), and the narrow femoral ring makes spontaneous reduction extremely unlikely. Immediate surgical exploration is the standard of care — CT scanning to "exclude strangulation" before operating introduces dangerous delay. ### Why Immediate Surgery (Option D) is Correct | Feature | This Patient | Significance | |---------|-------------|--------------| | Femoral hernia | Yes | Highest strangulation risk of all hernias | | Irreducible | Yes | Incarceration confirmed | | Acute SBO on X-ray | Yes | Obstruction confirmed | | Tender hernia | Yes | Suggests early vascular compromise | | Duration 8 hours | Yes | Bowel viability window narrowing | | Lactate 1.8 mmol/L | Borderline | Does NOT exclude early ischemia | | WBC 11,200 | Mildly elevated | Consistent with early strangulation | **High-Yield (Bailey & Love / Schwartz's Principles of Surgery):** The combination of an **irreducible, tender femoral hernia + acute small bowel obstruction** mandates **immediate surgical exploration**, regardless of whether systemic signs of strangulation (fever, shock, peritonitis) are fully manifest. Early strangulation can exist without overt systemic toxicity; waiting for these signs risks bowel necrosis and perforation. ### Why the Other Options Are Wrong - **Option A (CT first, then conservative if no strangulation):** CT cannot reliably exclude early bowel ischemia. Delaying surgery for imaging in an obstructed, irreducible femoral hernia is not standard practice and risks progression to frank strangulation. CT is appropriate for *reducible* hernias or ambiguous cases — not for confirmed incarceration with obstruction. - **Option B (NG tube + observation 24–48 hours):** Conservative management is appropriate for adhesive SBO, NOT for hernial obstruction. An irreducible hernia causing obstruction will not resolve with NG decompression; the mechanical cause (incarcerated hernia) must be surgically addressed. - **Option C (Manual reduction under sedation):** Attempted reduction (taxis) of a femoral hernia is **contraindicated** when the hernia is tender and has been irreducible for 8 hours. Forcible reduction risks reducing ischemic/necrotic bowel into the abdomen (en masse reduction), causing peritonitis. This is especially dangerous with femoral hernias given the rigid femoral ring. **Clinical Pearl (Schwartz's Principles of Surgery, 11th ed.):** "All incarcerated hernias causing intestinal obstruction should be treated by urgent operative repair. The femoral hernia, because of its narrow neck and rigid boundaries, has the highest rate of strangulation and should be repaired on an emergency basis once diagnosed with obstruction." **Mnemonic — FEMORAL = FAST SURGERY:** - **F**emoral hernias strangulate frequently - **E**mergency repair for obstruction - **M**anual reduction contraindicated if tender - **O**bstruction = operative indication - **R**igid ring = no spontaneous resolution - **A**void CT delay in confirmed incarceration - **L**actate normal does NOT exclude early ischemia