Is appendicitis with phlegmon initially managed surgically or medically?

Management of Appendicitis with Phlegmon

Initial management of appendicitis with phlegmon should be non-operative with antibiotics, with or without percutaneous drainage if an abscess is present, reserving surgery for settings with advanced laparoscopic expertise or when non-operative management fails. 1

Initial Treatment Approach

The choice between medical and surgical management depends critically on local surgical expertise and imaging findings:

Non-Operative Management (First-Line in Most Settings)

Non-operative management with antibiotics ± percutaneous drainage is the recommended first-line treatment for appendicitis with phlegmon or abscess when advanced laparoscopic expertise is not readily available. 1, 2

• This approach is associated with fewer complications and shorter overall hospitalization compared to immediate surgery 2
• Percutaneous drainage combined with antibiotics should be used when interventional radiology is available and an abscess (not just phlegmon) is present 2
• Approximately 70-90% success rate with percutaneous drainage for larger collections 1
• Selected patients presenting several days after symptom onset with phlegmon or small abscess not amenable to drainage may be treated with antimicrobial therapy alone 1

Surgical Management (Alternative First-Line with Expertise)

Laparoscopic appendectomy is suggested as the treatment of choice when advanced laparoscopic expertise is available, with a low threshold for conversion. 1

• Operative management in experienced hands may be associated with shorter length of stay, reduced readmissions, and fewer additional interventions than conservative treatment 1
• Both laparoscopic and open appendectomy are acceptable, dictated by surgeon expertise 1

Antibiotic Regimen

• Broad-spectrum antibiotics effective against facultative/aerobic gram-negative organisms and anaerobes are required 1
• If proceeding to surgery, administer a single preoperative dose of broad-spectrum antibiotics (0-60 minutes before incision) 1, 2
• For complicated appendicitis, postoperative antibiotics should not exceed 3-5 days if adequate source control achieved 1

When Surgery Becomes Mandatory

Immediate surgical intervention is indicated for:

• Clinical deterioration, hemodynamic instability, or diffuse peritonitis 2
• Failure of non-operative management (approximately 25% of patients with appendiceal abscess) 1, 3
• Settings where percutaneous drainage is not available or feasible 1, 2
• Patients with peritoneal signs on examination 1

Interval Appendectomy Considerations

Routine interval appendectomy is NOT recommended after successful non-operative management in patients <40 years old. 1, 2

• Recurrence rate after non-operative management ranges from 12-24% 1
• Interval appendectomy prevents recurrence in only 1 in 8 patients, making routine performance unjustified from a cost-benefit perspective 1
• Perform interval appendectomy only for patients with recurrent symptoms 1, 2

Critical Exception for Older Adults

For patients ≥40 years old, both colonoscopy and interval full-dose contrast-enhanced CT scan are recommended after non-operative treatment due to a 3-17% incidence of appendicular neoplasms in this age group. 1, 2

Common Pitfalls to Avoid

• Attempting immediate appendectomy without advanced laparoscopic skills often results in technically demanding procedures ending in ileocecal resection or right hemicolectomy 4, 5
• Failing to obtain CT imaging to distinguish phlegmon from abscess, which fundamentally changes management 2
• Delaying surgical consultation when non-operative management fails—approximately 25% will require operative intervention 1
• Performing routine interval appendectomy in young patients, which adds unnecessary operative costs and morbidity 1, 6
• Missing underlying malignancy in patients ≥40 years old by not performing appropriate follow-up imaging and colonoscopy 1, 2

Algorithm Summary

1. CT scan confirmation of phlegmon vs abscess 2
2. If abscess present + interventional radiology available: Percutaneous drainage + antibiotics 1, 2
3. If phlegmon or abscess without drainage capability + no advanced laparoscopic expertise: Antibiotics alone 1
4. If advanced laparoscopic expertise available: Consider laparoscopic appendectomy as first-line 1
5. If clinical deterioration or failure: Immediate surgery 2, 3
6. If age ≥40 and non-operative management successful: Colonoscopy + CT follow-up 1, 2