Outcomes of appendiceal phlegmon: diagnosis and treatment tactics

Aim. To determine prognostic factors of recurrences of acute appendicitis after appendiceal phlegmon (AP), as well as dependence of acute appendicitis recurrence on the results of laboratory and instrumental tests performed at first hospitalization.

Materials and methods. Prospective cohort study of 37 cases of acute appendicitis complicated by AP at presentation and during at least 5 years after successful conservative therapy was performed. Primary hospitalizations occurred between January of 2014 and December of 2019 at the Aleksandro-Mariinsky Regional Clinical Hospital and City Clinical Hospital No. 3 named after S. M. Kirov in Astrakhan.

At hospitalization, medical history and clinical signs of the disease were evaluated; for evaluation of systemic inflammatory reaction, measurements of acute inflammation markers (C-reactive protein and serum ferritin), as well as spiral computed tomography were performed. After successful conservative therapy, patients who did not undergo planned appendectomy were followed up for ≥ 60 months using a regional medical information system and active calls.

Results. Analysis of the results of laboratory tests (C-reactive protein and ferritin levels at hospitalization, on days 3 and 6 at the hospital) and spiral computed tomography at presentation allowed to identify predictors of disease recurrence of phlegmon treatment. These criteria allow to refine indications for delayed appendectomy which currently are not reflected in clinical guidelines.

After AP, recurrences of inflammatory process were reported in 35.1 % of cases, in the rest of the cases (64.9 %) the disease did not recur during the following 5 and more years.

Statistically significant predictors of disease recurrence were elevated C-reactive protein and ferritin in serum, changes in spiral computed tomography in the form of thickened fascia and / or presence of extraluminal gas reflecting severity of inflammation process and possible destruction of appendiceal tissues.

Conclusion. Depending on the levels of the studied criteria, AP can be classified into 2 types: severe (with the above-mentioned recurrence predictors) and mild (without the predictors) which allows to plan delayed treatment depending on the probability of disease recurrence.