Infections

Digestive System Diseases

All Conditions

Symptoms and General Pathology

Neoplasms

Appendicitis

Abscess

Appendiceal Neoplasms

Communicable Diseases

Intraabdominal Infections

Gastroenteritis

Gastrointestinal Diseases

Cecal Diseases

Intestinal Diseases

Suppuration

Inflammation

Cecal Neoplasms

Intestinal Neoplasms

Gastrointestinal Neoplasms

Digestive System Neoplasms

For all patients presenting with a periappendicular abscess, an interval appendectomy is planned at 2 to 3 months after initial conservative treatment, which is considered mandatory for all patients over 35 years of age. If a patient is under 35 and asymptomatic and does not want to undergo surgery, a follow-up MRI at 1 year will be performed.

interval appendectomy at 2 to 3 months after the initial non-operative treatment

Interval appendectomy

follow-up MRI at 1 year for asymptomatic patients under 35 years of age not wanting to undergo surgery

Follow-up MRI at 1 year

Paulina Salminen, prof, MD

Jenny Alajääski, MD

Complicated and uncomplicated appendicitis follow different epidemiological trends also suggesting different pathophysiology behind these two different forms of appendicitis. In 3-10% of patients complicated acute appendicitis is enclosed by formation of a circumscribed periappendicular abscess. The clinically established practice of antibiotic therapy and drainage, if necessary, has been shown safe and effective, allowing the acute inflammatory process to subside in more than 90% of cases without surgery. The need of subsequent interval appendectomy has been questioned with appendicitis recurrence risk varying between 5-26%.

During trial enrollment in our randomized Peri-APPAC trial based on the interim analysis results with 17% appendiceal tumor rate in the study population, the trial was prematurely terminated based on ethical concerns. All the follow-up group patients were re-evaluated and surgery was offered and recommended to all follow-up group patients. After this assessment and additional appendectomies, two more tumors were diagnosed resulting in neoplasm rate of 20% in the whole study group all diagnosed in patients over 40 years and the neoplasm rate in patients over 40 years was 29%.

Based on high appendiceal tumor rate in patients over 40 years, the appendiceal neoplasm rate needs to be further evaluated in prospective patient cohorts undergoing interval appendectomy as interval appendectomy is generally well tolerated and obliterates the risk of missing a possible tumor. In a recent systematic review of retrospective cohort studies with 13.244 acute appendicitis patients the overall appendiceal tumor rate was 1% after appendectomy, but in patients presenting with appendiceal inflammatory mass the neoplasm rate varied from 10% to 29%.

This nationwide prospective multicenter cohort study is designed to assess the prevalence of appendiceal tumors associated with a periappendicular abscess. All consecutive patients presenting with a periappendicular abscess are recommended to undergo interval appendectomy after initial conservative treatment with antibiotic therapy and drainage, if necessary. All patients older than 35 years will undergo laparoscopic interval appendectomy at 2 to 3 months and this is also recommended for the patients between 18 and 35 years of age. Asymptomatic patients under 35 years not willing to undergo interval appendectomy, will undergo a follow-up MRI at 1 year after the initial non-operative treatment.

Complicated and uncomplicated appendicitis follow different epidemiological trends also suggesting different pathophysiology behind these two different forms of appendicitis. In 3-10% of patients complicated acute appendicitis is enclosed by formation of a circumscribed periappendicular abscess. The clinically established practice of antibiotic therapy and drainage, if necessary, has been shown safe and effective, allowing the acute inflammatory process to subside in more than 90% of cases without surgery. The need of subsequent interval appendectomy has been questioned with appendicitis recurrence risk varying between 5-26%.

During trial enrollment in our randomized Peri-APPAC trial, the high incidence of appendiceal tumors in the study population alarmed the researchers. Based on the interim analysis results with 17% appendiceal tumor rate in the study population, the trial was prematurely terminated based on ethical concerns. All the follow-up group patients were re-evaluated and surgery was offered and recommended to all follow-up group patients. After this assessment and additional appendectomies, two more tumors were diagnosed resulting in neoplasm rate of 20% in the whole study group all diagnosed in patients over 40 years and the neoplasm rate in patients over 40 years was 29%.

Based on high appendiceal tumor rate in patients over 40 years, the appendiceal neoplasm rate needs to be further evaluated in prospective patient cohorts undergoing interval appendectomy as interval appendectomy is generally well tolerated and obliterates the risk of missing a possible tumor. In a recent systematic review of retrospective cohort studies with 13.244 acute appendicitis patients the overall appendiceal tumor rate was 1% after appendectomy, but in patients presenting with appendiceal inflammatory mass the neoplasm rate varied from 10% to 29%.

This nationwide prospective multicenter cohort study is designed to assess the prevalence of appendiceal tumors associated with a periappendicular abscess. All of the study hospitals will have a common clinical protocol of recommending interval appendectomy to all patients presenting with a periappendicular abscess after initial conservative treatment with antibiotic therapy and drainage, if necessary. Considering the high rate of appendiceal neoplasms, all patients older than 35 years will undergo laparoscopic interval appendectomy at 2 to 3 months after the successful initial non-operative treatment and this is also recommended for the patients between 18 and 35 years of age. Asymptomatic patients under 35 years not willing to undergo interval appendectomy, will undergo a follow-up MRI at 1 year after the initial non-operative treatment.

The Prevalence of Appendiceal Tumours in Periappendicular Abscess

The Prevalence of Appendiceal Tumours in Patients Presenting With a Periappendicular Abscess - A Nationwide Prospective Cohort Study

IPD is available from the PI upon request, if needed.

Clavien-Dindo classification, interval appendectomy group

All patients both at primary treatment, interval appendectomy and follow-up

In case the patient does not under interval appendectomy

Oulu University Hospital

Tampere University Hospital

Kuopio University Hospital

Jyväskylä Central Hospital

Mikkeli Central Hospital

Lapland Central Hospital

Vaasa Central Hospital, Vaasa, Finland

Seinajoki Central Hospital

North Karelia Central Hospital

South Carelia Central Hospital

Päijänne Tavastia Central Hospital

Satakunta Central Hospital

Turku University Hospital

Professor of Surgery

Herbal and Botanical

All Drugs and Chemicals

Cola

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.

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.

Surgical removal of the vermiform appendix.

Appendectomy

Ognjen Barcot, MD, PhD

Damir Quien, MD

This study seeks to justify performing an incidental appendectomy according to the following hypotheses:

1. 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)
2. The number needed to treat (NNT) for appendiceal tumors in the elderly is less than 500.
3. The rate of complicated AA in the elderly population is significantly higher than in the younger age group
4. NNT IA for complicated appendicitis in the elderly is less than 300.
5. NNT IA for potential death due to AA in the elderly is less than 500.

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).

Justification of Incidental Appendectomy With Respect to Pathohistological Findings

The data will be available upon reasonable request by the corresponding author (Ognjen Barcot).

Receiver operating curve analysis of the size of the vermiform appendix impacting the classification to neoplastic appendix

Receiver operating curve analysis of the age of the patient impacting the classification to neoplastic appendix

Receiver operating curve analysis of the age of the patient impacting the classification to the complicated appendicitis or death

Incidence of appendiceal neoplasms in IA which will be compared to the incidence of appendiceal neoplasms AA from respective PH samples.

The number of needed incidental appendectomies necessary to avoid one occurence of appendiceal neoplasm

Comparison of incidences of complicated appendicits in young vs elderly

The number of needed incidental appendectomies necessary to avoid one occurence of complicated appendicitis in elderly

The number of needed incidental appendectomies necessary to avoid one death from complicated appendicitis in elderly

University Hospital of Split

Ass. Prof.

Rare Diseases

Adenocarcinoma

Neoplasm Metastasis

Carcinoid Tumor

Adenocarcinoma, Mucinous

Cystadenocarcinoma

Neoplasms, Cystic, Mucinous, and Serous

Carcinoma

Neoplasms, Glandular and Epithelial

Neoplasms by Histologic Type

Neuroendocrine Tumors

Neuroectodermal Tumors

Neuroectodermal Tumors, Primitive

Neoplasms, Germ Cell and Embryonal

Neoplasms, Nerve Tissue

Adenocarcinoma of the Appendix

Neuroendocrine Tumor

Neuroepithelioma

Anti-Infective Agents

Formaldehyde

Individuals ages 18+ years with an appendix cancer diagnosis in the United States.

Individuals ages 18+ years with an appendix cancer diagnosis seen at Vanderbilt.

Biological parents of active GAP (Social and Vanderbilt) Study participants.

Genetic profiling

Collection of archived fixed-formalin, paraffin-embedded (FFPE) primary appendix tumor tissues that were previously removed

Retrospective tissue procurement

GAP Study Coordinator (Rebecca B.)

Andreana N Holowatyj, PhD, MSCI

The GAP Study is a prospective cohort study designed to comprehensively investigate genetic variations that may contribute to cancer development among individuals diagnosed with appendix/appendiceal cancer who are ages 18+ years.

The Genetics of Appendix Cancer (GAP) Study aims to analyze hereditary factors, tumor characteristics and clinical features/outcomes among adults diagnosed with appendix cancer and their biological parents. Patients are recruited at any time after a diagnosis of appendix cancer and followed for up to 6 years after study enrollment. This cohort is enriched by robust biospecimens and data collections.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
The Prevalence of Appendiceal Tumours in Periappendicular Abscess	NCT04634448	Appendix Absces... Appendicitis Appendix Mass Appendix Cancer Appendix Nec Appendix Tumor Appendix Diseas...	Interval append... Follow-up MRI a...	18 Years -	Turku University Hospital
Justification of Incidental Appendectomy With Respect to Pathohistological Findings	NCT05202600	Appendix Tumor	Appendectomy	18 Years -	University Hospital of Split
Genetics of Appendix Cancer Study	NCT05734430	Appendix Cancer Appendiceal Can... Appendiceal Neo... Appendiceal Muc... Appendiceal Ade... Appendiceal Car... Appendiceal Neo... Appendix Adenoc... Appendix Mucino... Appendix Tumor Appendix Cancer... Appendix NET Low-Grade Appen... High Grade Appe... High Grade Appe...	Genetic profili... Retrospective t...	18 Years -	Vanderbilt-Ingram Cancer Center
Genetics of Appendix Cancer Study	NCT05734430	Appendix Cancer Appendiceal Can... Appendiceal Neo... Appendiceal Muc... Appendiceal Ade... Appendiceal Car... Appendiceal Neo... Appendix Adenoc... Appendix Mucino... Appendix Tumor Appendix Cancer... Appendix NET Low-Grade Appen... High Grade Appe... High Grade Appe...	Genetic profili... Retrospective t...	18 Years -	Vanderbilt-Ingram Cancer Center

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