Justification of Incidental Appendectomy With Respect to Pathohistological Findings

Study Overview
=================
Brief Summary
-----------------
This study seeks to justify performing an incidental appendectomy according to the following hypotheses: The frequency of neoplasms in pathohistological (PHD) findings of incidental appendectomy (IA) is significantly higher than in PHD findings in appendectomies for acute appendcitis (AA) The number needed to treat (NNT) for appendiceal tumors in the elderly is less than 500. The rate of complicated AA in the elderly population is significantly higher than in the younger age group NNT IA for complicated appendicitis in the elderly is less than 300. NNT IA for potential death due to AA in the elderly is less than 500.

Detailed Description
-----------------
A retrospective cross-sectional study will be done. The archive of all PHD findings will be searched, and then the relevant medical histories at the Clinic of Surgery, University Hospital Center Split in the period from 01.01.2017. to 31.12.2021. The data collection will be done in the period from 01.02.2022. to 31.03.2022. The data collection (extraction) will be done by the main researcher (graduate, Ante Tavra) with at least two other colleagues from the Department of Abdominal-Coloproctological Surgery, University Hospital Center Split (Damir Quien, MD and Dora Bjelanović, MD). Data will be collected directly from medical history and entered into an overview table. The identity of the respondents will remain secret, and the respondents will be marked exclusively with an identification number. This type of research does not require the informed consent of the patient, and all data collected will be kept in accordance with the provisions of Annex 2 of the Application to Institutional advisory board of UHC Split (approval pending).

Official Title
-----------------
Justification of Incidental Appendectomy With Respect to Pathohistological Findings

Conditions
-----------------
Appendix Tumor

Intervention / Treatment
-----------------
* Procedure: Appendectomy


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Adult patients operated for colon tumors who have data on age, sex, data on a previously diagnosed colon tumor, data on incidental appendectomy, and a PHD finding for a removed appendix. Adult patients who have been diagnosed with acute appendicitis and have data on age, sex, data on the diagnosis of acute appendicitis and accompanying PHD findings, newly performed appendectomies. Exclusion Criteria: We will exclude from the analysis patients who had previous appendectomy, appendectomy has not been performed or we do not have an accompanying PHD finding of the appendix, and patients younger than 18 years.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Incidental appendectomy (IA)<br>Group IA will include adult patients operated on for colon tumors who have data on age, sex, data on a previously diagnosed colon tumor, data on incidental appendectomy, and a PHD finding for a removed vermiform appendix. | Procedure: Appendectomy<br>* Surgical removal of the vermiform appendix.<br>* Other names: Appendicectomy;|
| Acute appendectomy (AA)<br>Group AA will include adult patients who have been operated due to clinical suspicion of acute appendicitis and have data on age, sex, data on the diagnosis of acute appendicitis and accompanying PHD findings of the performed appendectomy. | Procedure: Appendectomy<br>* Surgical removal of the vermiform appendix.<br>* Other names: Appendicectomy;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of appendiceal neoplasms | Incidence of appendiceal neoplasms in IA which will be compared to the incidence of appendiceal neoplasms AA from respective PH samples. | 01.01.2017. - 31.12.2021. | 
| NNT of IA for the appendiceal neoplasm | The number of needed incidental appendectomies necessary to avoid one occurence of appendiceal neoplasm | 01.01.2017. - 31.12.2021. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of complicated appendicits | Comparison of incidences of complicated appendicits in young vs elderly | 01.01.2017. - 31.12.2021. | 
| NNT of IA for the complicated appendicits in elderly | The number of needed incidental appendectomies necessary to avoid one occurence of complicated appendicitis in elderly | 01.01.2017. - 31.12.2021. | 
| NNT of IA for the death due to appendicits in elderly | The number of needed incidental appendectomies necessary to avoid one death from complicated appendicitis in elderly | 01.01.2017. - 31.12.2021. |