What is the recommended management for acute appendicitis, including the preferred surgical approach, peri‑operative antibiotic regimen, and treatment options for perforated or complicated disease?

Management of Acute Appendicitis

Laparoscopic appendectomy is the preferred treatment for both uncomplicated and complicated acute appendicitis, performed within 24 hours of admission, with a single preoperative antibiotic dose and no routine postoperative antibiotics for uncomplicated cases. 1

Surgical Approach

Laparoscopic appendectomy should be performed over open appendectomy in all patients where equipment and expertise are available. 1 This approach provides:

• Less postoperative pain on day one 1
• Lower surgical site infection rates (significantly reduced across all meta-analyses) 1
• Shorter hospital stay by 0.16 to 1.13 days 1
• Earlier return to work and better quality of life scores 1

The historical concern about higher intra-abdominal abscess rates with laparoscopy has disappeared in studies published after 2001, with current evidence showing no significant difference between approaches. 1

Technical Considerations

• Use conventional three-port laparoscopic technique rather than single-incision 2, as single-incision results in longer operative times (7.6-18.3 minutes longer), higher analgesic requirements, and increased wound infection rates 1
• Simple ligation of the appendiceal stump is preferred over stump inversion in both laparoscopic and open approaches 3
• Remove the appendix even if it appears macroscopically normal during exploration, as 27.8% of "normal-appearing" appendices show inflammation on histopathology 3

Pediatric Patients

Laparoscopic appendectomy is strongly recommended for children where expertise is available. 1 Benefits include:

• Lower surgical site infection rates (OR 0.28; 95% CI 0.25-0.31) 1
• No increase in intra-abdominal abscess rates (OR 0.79; 95% CI 0.45-1.34) 1
• Shorter hospital stay (mean difference -2.47 days) 1
• Faster return to oral intake (mean difference -0.88 days) 1

Perioperative Antibiotic Management

Preoperative Antibiotics

Administer a single dose of broad-spectrum antibiotics 0-60 minutes before surgical incision for all patients. 2, 4 Acceptable regimens include:

• Piperacillin-tazobactam monotherapy 5
• Cephalosporin plus metronidazole 5
• Fluoroquinolone plus metronidazole 5

Postoperative Antibiotics

For uncomplicated appendicitis with adequate source control, discontinue antibiotics after the single preoperative dose. 2, 4, 3

For complicated appendicitis (perforation, abscess, peritonitis), continue postoperative antibiotics for a maximum of 3-5 days when adequate source control is achieved. 4, 3, 6 Suggested regimen:

• Metronidazole 500 mg every 6 hours plus vancomycin 25-30 mg/kg loading dose, then 15-20 mg/kg every 8 hours 2

A key study demonstrated that shorter antibiotic duration (3-5 days) significantly decreased 30-day readmission rates (16% vs 2%; P < 0.017) without increasing infectious complications compared to traditional longer courses. 6

Management of Complicated Appendicitis with Abscess or Phlegmon

When advanced laparoscopic expertise is available, proceed directly with laparoscopic appendectomy as first-line treatment. 1, 2, 4 This approach results in:

• Fewer readmissions than conservative management 1, 2, 7
• Fewer additional interventions 1, 2
• Comparable hospital stay to non-operative management 1

When laparoscopic expertise is unavailable, use non-operative management with intravenous antibiotics plus percutaneous drainage for accessible abscesses. 1, 4, 3 Percutaneous drainage achieves 70-90% efficacy for mature abscesses. 3

Interval Appendectomy

Routine interval appendectomy is NOT recommended after successful non-operative management. 1, 4 The recurrence rate after non-operative treatment ranges from 12-24%, but interval appendectomy adds operative costs to prevent recurrence in only one of eight patients. 1

Reserve interval appendectomy only for patients with recurrent symptoms. 2, 4

Age-Specific Surveillance

For patients ≥40 years old treated with any approach (operative or non-operative), perform both colonoscopy and interval contrast-enhanced CT scan due to 3-17% incidence of appendiceal or colonic neoplasms. 2, 4, 3

Timing of Surgery

Perform appendectomy within 24 hours of admission for uncomplicated appendicitis. 2, 4, 3 Delays beyond 24 hours increase complications, and delays beyond 48 hours significantly increase surgical site infections and adverse events. 4, 3

For complicated appendicitis with perforation or abscess, perform surgery within 8 hours when possible. 2 When shock, gangrene, or free perforation with diffuse peritonitis is present, immediate operative intervention is mandatory. 3

Intraoperative Management

Document disease severity using a standardized grading system (WSES 2015 or AAST EGS score) based on clinical, imaging, and operative findings. 1, 2, 3 This allows:

• Identification of homogeneous patient groups 1
• Determination of optimal postoperative management 1
• Improved resource utilization 1

Do not place abdominal drains following appendectomy for complicated appendicitis in adults or children, as they provide no benefit in preventing intra-abdominal abscess and lead to longer hospitalization. 2, 3

Do not routinely perform intraoperative irrigation, as it does not prevent intra-abdominal abscess formation. 3

Wound Management for Open Appendectomy

When open appendectomy is performed for contaminated/dirty wounds:

• Use wound ring protectors to decrease surgical site infection risk 1
• Perform primary skin closure with a single absorbable intradermal suture rather than delayed primary closure, as delayed closure increases hospital stay and costs without reducing infection risk 1

Postoperative Care

Routine histopathology is mandatory after appendectomy to identify unexpected findings, as the incidence of unexpected disease (though low) cannot be detected by intraoperative diagnosis alone. 1, 3

Outpatient laparoscopic appendectomy is safe and feasible for selected patients with uncomplicated appendicitis, with complication rates of 2.4% in outpatients versus 11.7% in inpatients (P = 0.16). 8

Critical Pitfalls to Avoid

• Never delay appendectomy beyond 24 hours from admission without compelling reason, as delays beyond 48 hours significantly increase morbidity 4, 3
• Do not rely on macroscopic appearance alone to decide whether to remove the appendix—surgeon judgment is inaccurate and 27.8% of "normal" appendices are inflamed histologically 4, 3
• Do not continue postoperative antibiotics beyond 3-5 days in complicated appendicitis with adequate source control 4, 3
• Maintain a low threshold for conversion to open surgery in complicated cases with technical difficulties, particularly when shock is present 3
• Do not use single-incision laparoscopic technique as it offers no clinical advantage and results in longer operative times and higher wound infection rates 2, 3