RD7.4 | Imaging in Strangulated Hernia — Summary & Reflection

KEY TAKEAWAYS

Imaging in Strangulated Hernia — Key Points

• Strangulation is a CLINICAL diagnosis — a tense, tender, irreducible hernia with bowel obstruction goes to theatre after resuscitation; do NOT delay an obvious case for confirmatory imaging.
• Imaging is for the equivocal case — the difficult-to-examine or obese patient, obstruction with no obvious external hernia (obturator/internal), and for mapping complications and viability.
• Ultrasound (bedside): non-reducible loop in the sac, absent peristalsis, free fluid, and absent colour-flow on Doppler (ischaemia); radiation-free, operator-dependent.
• Contrast-enhanced CT abdomen/pelvis is the modality of choice for confirmation and complication mapping; it directly assesses bowel-wall enhancement.
• Cardinal CT sign of ischaemia = poor or absent bowel-wall enhancement. Supportive signs: bowel-wall thickening, closed-loop (C/U-shaped) obstruction, free fluid, mesenteric oedema/fat stranding, and the late, ominous pneumatosis intestinalis / portal venous gas; free gas = perforation.
• A simple incarcerated (viable) hernia still ENHANCES normally with preserved wall and minimal free fluid — the imaging counterpart of trapped but living bowel.
• Integrate into management: ischaemia → urgent operation with resection of non-viable bowel + resuscitation, NG tube, antibiotics; viable trapped loop → operative reduction and repair; perforation → emergency surgery.
• Femoral hernias strangulate readily — low threshold to image and operate. NEVER force-reduce a strangulated hernia ('reduction en masse' hides dead bowel).

REFLECT

On your next surgical posting, watch how the registrar handles an irreducible hernia. Notice the moment the decision is made — is it made clinically at the bedside, or is a scan requested, and why? When a CT is done, look at the trapped loop yourself and ask the one question that matters most: does it enhance? Linking that single observation to the operative plan — resect if dead, preserve if alive — is the applied essence of RD7.4. And remember the cautionary tale of 'reduction en masse': the urge to push a painful lump back in can bury a catastrophe. The discipline of knowing when imaging helps and when it merely delays is what separates safe surgical practice from dangerous habit.