A 28-year-old woman presents with a 48-hour history of right lower quadrant pain, fever (38.5°C), and vomiting. On examination, she has marked tenderness and guarding in the RLQ with a palpable mass. WBC is 14,200/μL. CT abdomen with contrast shows a 5 cm fluid collection adjacent to the appendix with appendiceal wall enhancement and periappendiceal stranding. The patient is hemodynamically stable. What is the most appropriate management?

Explanation

## Management of Complicated Appendicitis with Abscess **Key Point:** This patient has **complicated acute appendicitis with a well-defined periappendiceal abscess** (5 cm fluid collection). In a hemodynamically stable patient, the standard approach is **percutaneous drainage of the abscess + interval appendicectomy** rather than immediate surgery. ### Clinical Features of Complicated Appendicitis | Finding | Significance | |---------|---------------| | 48-hour duration | Allows time for localization of infection | | Palpable RLQ mass | Suggests abscess formation | | CT: 5 cm fluid collection | Well-defined, localized abscess | | Appendiceal wall enhancement | Inflammation/infection | | Hemodynamically stable | Can tolerate percutaneous drainage | | Fever + leukocytosis | Ongoing infection | ### Treatment Algorithm for Complicated Appendicitis ```mermaid flowchart TD A[Acute Appendicitis]:::outcome --> B{Perforation with Abscess?}:::decision B -->|No Abscess| C[Immediate Appendicectomy]:::action B -->|Well-defined Abscess| D{Hemodynamically Stable?}:::decision D -->|Yes| E[Percutaneous Drainage]:::action D -->|No| F[Immediate Surgery]:::urgent E --> G[Antibiotics 5-7 days]:::action G --> H[Interval Appendicectomy at 6-8 weeks]:::action H --> I[Histopathology to rule out malignancy]:::outcome ``` ### Why Percutaneous Drainage + Interval Appendicectomy? **High-Yield:** The **Percutaneous Drainage and Interval Appendicectomy (PDIA) strategy** is the standard for stable patients with localized abscess: 1. **Percutaneous drainage** (under CT or ultrasound guidance) → decompresses the abscess, controls infection, allows the patient to stabilize 2. **Broad-spectrum antibiotics** → cover gram-negative and anaerobic organisms (e.g., piperacillin-tazobactam or ceftriaxone + metronidazole) 3. **Interval appendicectomy** → performed 6–8 weeks later after inflammation resolves, reducing operative morbidity and mortality **Clinical Pearl:** Immediate surgery in the presence of a localized abscess increases the risk of: - Spillage of pus into the peritoneal cavity - Generalized peritonitis - Sepsis - Anastomotic leak (if primary repair attempted) - Higher morbidity and mortality Percutaneous drainage allows the infection to be controlled in a controlled manner, and the subsequent interval appendicectomy is performed in a cleaner surgical field. ### When to Proceed to Immediate Surgery - **Hemodynamic instability** (septic shock, hypotension) - **Generalized peritonitis** (not localized abscess) - **Failed percutaneous drainage** or inability to place drain - **Perforation without abscess formation** This patient is **hemodynamically stable** with a **well-defined abscess** → **percutaneous drainage + interval appendicectomy** is the correct approach. **Warning:** Do NOT attempt immediate appendicectomy in a stable patient with a localized abscess — this is associated with higher morbidity. Do NOT treat with antibiotics alone without drainage — the abscess must be decompressed. **Mnemonic:** **PDIA** = **P**ercutaneous **D**rainage + **I**nterval **A**ppendectomy for stable patients with localized abscess. [cite:Sabiston Textbook of Surgery 21e Ch 51; Schwartz's Principles of Surgery 11e Ch 31]