A 42-year-old woman with no prior abdominal surgery presents with acute-onset severe, constant abdominal pain, vomiting, and abdominal distension for 6 hours. On examination, she is febrile (38.5°C), tachycardic (110 bpm), and has a rigid, tender abdomen with absent bowel sounds. Plain abdominal X-ray shows a markedly dilated loop of small bowel with a 'coffee bean' appearance and a transition point. CT abdomen with IV contrast reveals a twisted mesenteric root with a 'whirlpool' sign and compromised vascular supply. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis and Management: Small Bowel Volvulus **Key Point:** Small bowel volvulus is a surgical emergency requiring immediate operative intervention. Unlike adhesive obstruction, volvulus carries a high risk of bowel ischemia and necrosis, and conservative management is contraindicated. ### Clinical Red Flags for Volvulus 1. **Acute, severe pain** — often out of proportion to physical findings initially 2. **Fever and tachycardia** — suggest ischemia and peritonitis 3. **Rigid, tender abdomen with absent bowel sounds** — indicate advanced obstruction with possible perforation 4. **No prior abdominal surgery** — volvulus can occur de novo, unlike adhesions ### Imaging Findings Diagnostic of Volvulus | Finding | Modality | Significance | |---------|----------|---------------| | 'Coffee bean' sign | Plain X-ray | Twisted loop of bowel | | 'Whirlpool' sign | CT | Twisted mesenteric root with spiral configuration | | Transition point | CT | Abrupt change from dilated to collapsed bowel | | Compromised vascular supply | CT with contrast | Mesenteric vessels twisted; ischemia present | **High-Yield:** The **'whirlpool' sign** on CT is pathognomonic for volvulus — it represents the twisted mesentery and vessels spiraling around the axis of rotation. ### Why Immediate Surgery Is Mandatory ```mermaid flowchart TD A[Small bowel volvulus diagnosed]:::outcome --> B{Immediate surgery?}:::decision B -->|Yes| C[Untwist bowel loop]:::action C --> D{Bowel viable?}:::decision D -->|Yes| E[Close abdomen, resuscitate]:::action D -->|No| F[Resect necrotic segment]:::action B -->|No - conservative Mx| G[Bowel ischemia progresses]:::urgent G --> H[Transmural necrosis]:::urgent H --> I[Perforation, sepsis, death]:::urgent ``` **Clinical Pearl:** Volvulus causes **complete obstruction with vascular compromise**. Every hour of delay increases the risk of irreversible ischemia and mortality. The presence of fever and rigid abdomen suggests that ischemia has already begun. ### Pathophysiology of Volvulus 1. Twisting of the mesentery around its root (usually at the ligament of Treitz) 2. Obstruction of the bowel lumen → increased intraluminal pressure 3. Compression of mesenteric vessels → venous congestion → arterial compromise 4. Transmural ischemia → necrosis → perforation → peritonitis and septic shock ### Operative Management - **Untwist the volvulus** to restore blood supply - **Assess viability** of the bowel (color, peristalsis, bleeding from cut edge) - **Resect** any segment with full-thickness necrosis - **Avoid primary anastomosis** if the patient is unstable; consider staged repair - **Second-look laparotomy** may be needed 24–48 hours later if viability is uncertain **Mnemonic:** **VOLVULUS = Vascular compromise + Obstruction + Loss of blood supply + Urgent Laparotomy + Untwist + Likely resection + Urgent Surgery** [cite:Sabiston Textbook of Surgery 21e Ch 48; Bailey & Love's Short Practice of Surgery 27e Ch 72]