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The Prevalence of Appendiceal Tumours in Periappendicular Abscess

Not Applicable
Not yet recruiting
Conditions
Appendicitis
Appendix Cancer
Appendix Tumor
Appendix Diseases
Appendix Abscess
Appendix Mass
Appendix Nec
Interventions
Procedure: Interval appendectomy
Diagnostic Test: Follow-up MRI at 1 year
Registration Number
NCT04634448
Lead Sponsor
Turku University Hospital
Brief Summary

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.

Detailed Description

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.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
400
Inclusion Criteria
  • periappendiceal abscess proven by CT, Mri or US
Exclusion Criteria
  • patient declines to participate, complicated appendicitis without periappendiceal abscess

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Interval appendectomyInterval appendectomyFor 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.
Follow-up MRIFollow-up MRI at 1 yearFor 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.
Primary Outcome Measures
NameTimeMethod
The Prevalence of Appendiceal Tumours in Periappendicular Abscess2-3 months (interval appendectomy)

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

Secondary Outcome Measures
NameTimeMethod
follow-up CEAat 1 year

Follow-up MRI patients

follow-up CgAat 1 year

Follow-up MRI patients

Interval appendectomy specimen histologyAt 3 months

Interval appendectomy patients

Complications after interval appendectomyat the time of surgery

Clavien-Dindo classification, interval appendectomy group

Follow-up MRI findingsat 1 year

In case the patient does not under interval appendectomy

Laboratory value: neutrophilsDay 0 (on primary admission) up to 3-5 days (discharge from the hospital)

neutr

Laboratory value: hemoglobinDay 0 (on primary admission) up to 3-5 days (discharge from the hospital)

Hb

Laboratory value: kreatinineDay 0 (on primary admission) up to 3-5 days (discharge from the hospital)

Krea

Laboratory value: CEADay 0 (on primary admission) up to 3-5 days (discharge from the hospital) and up to 1 year, if no interval appendectomy

CEA

Tympanic temperatureDay 0 (on primary admission)

All patients

Imaging (primary diagnosis) findingDay 0 (on primary admission)

All patients

Duration of symptoms on admissionDay 0 (on primary admission)

All patients

Laboratory value: CRPDay 0 (on primary admission) up to 3-5 days (discharge from the hospital)

CRP

Laboratory value. Cg-ADay 0 (on primary admission) up to 3-5 days (discharge from the hospital)and up to 1 year, if no interval appendectomy

Cg-A

Primary nonoperative treatmentDay 0 and up to one week

All patients, treatment details

Colonoscopy: endoscopic findings and histology2 weeks to 2 months prior to planned interval appendectomy

In both intervention groups

Laboratory value: leuckocytesDay 0 (on primary admission) up to 3-5 days (discharge from the hospital)

leuk

Surgery after follow-up MRIup to 10 years

Follow-up with MRI patients

Duration of hospital stayup to 2 years

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

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