Hospital databases were searched to identify patients diagnosed with peri-appendiceal abscesses with procedure records for percutaneous drainage between January 2009 and December 2019.Theelectronic medical records of the 85 patients who were selected during the process were thoroughly reviewed. Among them, 27 patients were finally included for analysis, who received abscess drainage procedures for peri-appendiceal abscesses and planned to proceed with NOM. Patients who chose to receive delayed surgery after percutaneous abscess drainage or interval appendectomy without recurrence were excluded.
Treatment flow for peri-appendiceal abscess
Our surgical team followed the treatment guidelines published by the World Society of Emergency Surgery2. Surgical management is accepted as the gold-standard treatment for both simple acute appendicitis and perforated acute appendicitis. Appendectomy was performed as an initial treatment method in the following situations: 1) an abscess had formed at the tip or body of the appendix, with an intact appendix base and cecum; 2) there was a small abscess (≤ 2 ㎝); 3) an abscess had formed in a deep pelvic cavity or surrounded by adjacent bowel, which made the percutaneous approach difficult and risky. Patients with remaining abscesses and symptoms of appendicitis were managed by delayed appendectomy or resectional surgery.
For patients who underwent percutaneous drainage for peri-appendiceal abscesses, detailed counselling was carried out by a responsible surgeon to establish a further treatment plan. After pigtail insertion, the patients were checked by outpatient clinics. If the clinical presentation had disappeared and signs of recurrence were absent or the abscess was not found on the computed tomography (CT) scan, the next therapeutic step was discussed with the patient. Additionally, if the patient did not wish to undergo surgery and accepted the risks of recurrence, then the pigtail catheter was removed 4 to 6 weeks after insertion. Additionally, the surgical team told the patient to visit the clinic or emergency room if they had any symptoms or signs of possible acute appendicitis. Non-operative management was performed if the following criteria applied: 1) the patient did not want to undergo surgery; 2) the patient had risk factors for postoperative complications, such as severe underlying comorbidities; 3) the patient had other intra-abdominal pathologies, such as metastatic cancer or carcinomatosis.
Baseline characteristics, such as age, sex, and comorbidities, were collected through the electronical medical record. The initial complete blood counts, initial delta-neutrophil indices, C-reactive protein (CRP) levels, initial vital signs, clinical outcomes, and lengths of the follow-up periods were also collected. Telephone calls were made to the patients to obtain information beyond that in their hospital records.
The patients’ baseline characteristics, initial statuses, and follow-up periods are expressed as medians (interquartile ranges) or means (± standard deviations). Categorical variables are presented as frequency (%). Statistical analysis was performed using SPSS® Statistics 23.0 (IBM Corp., Armonk, NY).