Ambulatory Surgery for Suspected Acute Appendicitis Has Similar Safety Outcomes

The SAT score is considered a reliable measure for identifying patients with suspected acute appendicitis eligible for ambulatory appendectomy.

Ambulatory surgery for suspected acute appendicitis on the basis of St-Antonine’s (SAT) score is considered safe and reliable, according to study findings published in the journal Surgery.

Acute appendicitis is considered the leading cause of gastrointestinal disorders, however, there is limited evidence on the safety of ambulatory appendectomy for suspected acute appendicitis. For this study, researchers sought to report on their experience of ambulatory appendectomy for suspected acute appendicitis using the SAT score and they sought to improve patient eligibility for this procedure.

Patients (N=1730) aged older than 15 years who underwent surgery for acute appendicitis at Hôpital Saint Antoine in France between 2013 and 2020 were included in this large, retrospective study. Outcomes of appendectomy procedures were evaluated on the basis of whether patients received ambulatory (n=451) or conventional (n=1279) surgical care. Patients with SAT score of 4 and higher were eligible for ambulatory surgery.

The patient population comprised 44.7% women or girls, 49.7% were younger than 30 years, and 94.4% had a body mass index (BMI) of less than 28 kg/m2.

The proportion of patients with SAT scores 0-5 were 0.4%, 4%, 13.9%, 26.6%, 35.8%, and 19.2%, respectively. Overall, 84.8% of cases had their diagnosis confirmed with a computed tomography scan.

We propose to extend the indication for ambulatory appendectomy to all patients without radiological evidence of perforation with a predicted success rate of 86.4%.

During surgery, 0.7% of patients were found to have no acute appendicitis. The remaining patients had uncomplicated acute appendicitis (75%), peritonitis (11%), gangrenous acute appendicitis (9.8%), and appendix abscess (3.5%). Most patients (62.9%) were free from abdominal fluid.

After the surgery, 29.8% received antibiotic therapy and 81% were discharged on days 0 or 1. Stratified by conventional and ambulatory operative pathways, the conventional group had a longer hospital stay (mean, 40 h 43 min vs 11 h 32 min; P <.001), a longer time from diagnosis to surgery (mean, 17 h 37 min vs 14 h 13 min; P <.001), and longer operative time (mean, 1 h 43 min vs 1 h 33 min; P <.001) compared with the ambulatory group, respectively.

Predictors of discharge on postoperative days 0 or 1 included no sign of perforation (odds ratio [OR], 6.073; 95% CI, 4.285-8.608; P <.001), C-reactive protein less than 30 mg/L (OR, 2.501; 95% CI, 1.873-3.340; P <.001), appendix diameter smaller than 10 mm (OR, 1.433; 95% CI, 1.081-1.898; P =.012), and white cell count less than 15,000/mL (OR, 1.380; 95% CI, 1.049-1.816; P =.012).

The ambulatory and conventional groups did not differ for rates of unplanned consultations or readmissions (5.1% vs 6.6%; P =.243), infectious complications (2.9% vs 5.1%; P =.053), morbidity (3.5% vs 5.3%; P =.133), and wound abscess and free fluid in right iliac fossa at 30 days (2.9% vs 4.2%; P .205), respectively.

The only predictor for postoperative morbidity was radiological evidence of perforation (hazard ratio [HR], 2.405; 95% CI, 1.341-4.314; P =.003).

The major limitation of this study was the differing proportion of patients who underwent conventional or ambulatory surgery.

This study found that 90.9% of ambulatory appendectomies with same-day discharges were successful, leading the researchers to conclude “We propose to extend the indication for ambulatory appendectomy to all patients without radiological evidence of perforation with a predicted success rate of 86.4%. However, the safety and the efficiency of this unique selection criterion should be confirmed prospectively in the future.”


Raimbert P, Voron T, Laroche S, et al. Ambulatory appendectomy for acute appendicitis: Can we treat all the patients? A prospective study of 451 consecutive ambulatory appendectomies out of nearly 2,000 procedures. Surgery. Published online February 10, 2023. doi:10.1016/j.surg.2023.01.003