Retrospective Cohort Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Oct 27, 2016; 8(10): 693-699
Published online Oct 27, 2016. doi: 10.4240/wjgs.v8.i10.693
Acute appendicitis: Epidemiology, treatment and outcomes- analysis of 16544 consecutive cases
Marco Ceresoli, Alberto Zucchi, Niccolò Allievi, Asaf Harbi, Michele Pisano, Giulia Montori, Arianna Heyer, Gabriela E Nita, Luca Ansaloni, Federico Coccolini
Marco Ceresoli, Niccolò Allievi, Asaf Harbi, Michele Pisano, Giulia Montori, Gabriela E Nita, Luca Ansaloni, Federico Coccolini, General Surgery Unit, Papa Giovanni XXIII Hospital, 24127 Bergamo, Italy
Alberto Zucchi, Epidemiology unit, ATS Provincia Bergamo, 24128 Bergamo, Italy
Arianna Heyer, University of California, Berkeley, CA 94720, United States
Author contributions: Ceresoli M, Zucchi A, Pisano M, Ansaloni L and Coccolini F designed the study; Ceresoli M, Zucchi A, Allievi N and Pisano M analyzed the data; Ceresoli M, Allievi N, Harbi A and Montori G wrote the paper; Pisano M, Heyer A, Nita GE, Ansaloni L and Coccolini F revised it critically; all the authors read and approved the final version of the manuscript.
Institutional review board statement: According to the Italian law for retrospective observational cohort studies no specific approvations by the review board is needed.
Informed consent statement: This is a retrospective cohort study. According to the Italian law and the Helsinki declaration on biohetics no informed consent by single patient is needed; moreover presented data are anonymized and risk of identification is null.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
Data sharing statement: Statistical code and dataset are available from the corresponding author at Consent was not obtained but the presented data are anonymized and risk of identification is null. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Dr. Marco Ceresoli, General Surgery Unit, Papa Giovanni XXIII Hospital, piazza OMS 1, 24127 Bergamo, Italy.
Telephone: +39-352-673486 Fax: +39-352-674963
Received: May 31, 2016
Peer-review started: June 1, 2016
First decision: July 20, 2016
Revised: August 4, 2016
Accepted: August 27, 2016
Article in press: August 29, 2016
Published online: October 27, 2016

To investigate the epidemiology, treatment and outcomes of acute appendicitis (AA) in a large population study.


This is a retrospective cohort study derived from the administrative dataset of the Bergamo district healthcare system (more than 1 million inhabitants) from 1997 to 2013. Data about treatment, surgery, length of stay were collected. Moreover for each patients were registered data about relapse of appendicitis and hospital admission due to intestinal obstruction.


From 1997 to 2013 in the Bergamo district we collected 16544 cases of AA, with a crude incidence rate of 89/100000 inhabitants per year; mean age was 24.51 ± 16.17, 54.7% were male and the mean Charlson’s comorbidity index was 0.32 ± 0.92. Mortality was < 0.0001%. Appendectomy was performed in 94.7% of the patients and the mean length of stay was 5.08 ± 2.88 d; the cumulative hospital stay was 5.19 ± 3.36 d and 1.2% of patients had at least one further hospitalization due intestinal occlusion. Laparoscopic appendectomy was performed in 48% of cases. Percent of 5.34 the patients were treated conservatively with a mean length of stay of 3.98 ± 3.96 d; the relapse rate was 23.1% and the cumulative hospital stay during the study period was 5.46 ± 6.05 d.


The treatment of acute appendicitis in Northern Italy is slowly changing, with the large diffusion of laparoscopic approach; conservative treatment of non-complicated appendicitis is still a neglected option, but rich of promising results.

Keywords: Acute appendicitis, Conservative treatment, Epidemiology, Laparoscopic appendectomy, Intestinal obstruction

Core tip: Acute appendicitis is the most common surgical emergency around the world. In the Bergamo district, northern Italy its incidence is 89/100000 inhabitants per year with a negative trend during the last years. Percent of 95 patients were treated with appendectomy, 48% of whom laparoscopically; 1.3% of operated patients had an intestinal obstruction during the follow-up. Conservative treatment resulted in a reduced length of stay but 23% of patients had a relapse during follow up. Cumulative length of stays during the study period was similar for the two treatment option.