A 52-year-old woman undergoes elective cholecystectomy. On post-operative day 5, the surgical site shows a sudden gush of serosanguinous fluid through the incision, with separation of the skin edges. The underlying fascia appears intact. Which investigation is most appropriate to assess the integrity of deeper layers and guide further management?

Explanation

## Post-operative Wound Dehiscence: Imaging Assessment ### Clinical Presentation Analysis The patient presents with **superficial wound dehiscence** (skin separation with serosanguinous drainage) on post-operative day 5. The clinical note states the **fascia appears intact**, but this must be objectively confirmed to rule out **fascial dehiscence** (a surgical emergency). ### Why Ultrasonography is the Investigation of Choice **Key Point:** Ultrasonography is the **first-line imaging modality** for assessing wound dehiscence because it: - **Directly visualizes the fascial layers** in real-time - Confirms **fascial integrity** (or identifies fascial defect) - Detects **fluid collections** (seroma, hematoma, abscess) - Is **non-invasive, portable, and cost-effective** - Can be performed at the bedside without sedation - Guides decision-making: superficial dehiscence (conservative) vs. fascial dehiscence (urgent re-exploration) **Clinical Pearl:** On ultrasound, the **fascia appears as a bright, hyperechoic linear structure**. Discontinuity or gap in this line indicates fascial dehiscence. A **hypoechoic collection** between skin and fascia suggests seroma/hematoma. ### Differential Diagnosis: Superficial vs. Fascial Dehiscence | Feature | Superficial Dehiscence | Fascial Dehiscence | |---|---|---| | **Timing** | Day 5–7 (usually) | Day 3–5 (earlier) | | **Presentation** | Serosanguinous drainage, skin separation | Sudden gush, evisceration risk | | **Fascia** | Intact (imaging confirms) | Disrupted | | **Management** | Conservative, local wound care | **Urgent surgical re-exploration** | | **Ultrasound finding** | Continuous fascia, fluid collection above | Discontinuous fascia, gap visible | ### Management Algorithm ```mermaid flowchart TD A[Post-op day 5: Wound dehiscence] --> B[Ultrasonography] B --> C{Fascia intact?} C -->|Yes| D[Superficial dehiscence] D --> E[Conservative management] E --> F[Daily dressing, monitor] C -->|No| G[Fascial dehiscence] G --> H[Urgent surgical re-exploration] H --> I[Re-suture/re-staple fascia] ``` **High-Yield:** Ultrasound can **differentiate superficial from fascial dehiscence** at the bedside, avoiding unnecessary CT and guiding urgent intervention if needed. **Mnemonic:** **FAST for Fascia Assessment** — **F**ascial integrity, **A**ssess layers, **S**eroma/fluid, **T**issue continuity.