Preserving or Resecting the Normal Appendix in Patients Undergoing Laparoscopy Surgery for Suspected Appendicitis

NCT ID: NCT06917612

Last Updated: 2025-04-08

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 20000 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2005-01-01
• Study Completion Date: 2023-12-31

Brief Summary

When appendicitis is suspected, patients are typically planned for emergency surgery preferably using a laparoscopic approach. Up to 20% of these patients will have a normal appendix, thus not suffering from appendicitis. Surgeons can either perform a normal diagnostic laparoscopy (leave the appendix in situ) or perform a negative appendectomy (resect the normal appendix). International guidelines recommend negative appendectomy based on weak evidence due to the risk of appendix cancer, but some countries and researchers advocate against negative appendectomy as these patients may experience more harm than if the appendix is left in situ. There are limited national guidelines and the decision is often left to the operating surgeon. Surgeons performing negative appendectomies argue that these prevent microappendicitis and the risk of a subsequent episode of appendicitis. As appendix cancers are rare, and a randomised controlled trial including this subgroup of patients with normal appendices undergoing emergency surgery for suspected appendicitis is unfeasible, an emulated target trial is planned.

This target trial aims to evaluate the effect of a normal diagnostic laparoscopy versus negative appendectomy during laparoscopic surgery for suspected appendicitis regarding cancer in the appendix and other complications such as death, reoperation, and readmission.

Detailed Description

The target trial emmulates an unfeasible randomised controlled trial by using observational data to investigate the two treatment strategies (two groups) normal diagnostic laparoscopy versus negative appendectomy when a normal appendix is seen during surgery for suspected appendicitis. The assignment to the treatment strategies during surgery for suspected appendicitis is treated as randomised within the levels of the following baseline covariates; sex, age, year of index surgery, and hospital through inverse probability weighting. We will analyse data according to treatment assignment at baseline (intention-to-treat). Because the treatment strategies in this target trial are surgical, all participants will adhere to the surgical treatment strategy: neither a normal diagnostic laparoscopy nor a negative appendectomy at index surgery can be reversed. However, both may be followed by a reoperation, e.g., a new normal diagnostic laparoscopy or a laparoscopic appendectomy (for suspected appendicitis or stump appendicitis). However, this will not influence analyses but be recorded as an outcome.

As inverse probability weighting has been applied, no further adjustment in the pre-specified analyses below is needed.

The continuous outcome, delay of cancer diagnosis for the normal diagnostic laparoscopy group, will be descriptively reported as mean (SD) or median (IQR).

For dichotomous outcomes, the following analyses are planned:

• Kaplan-Meier curves for each group
• Incidence proportion (risk) including 95% CI for each group
• Relative risk
• Risk difference
• Number needed to treat
• Number needed to harm
• Test chi-square

Conditions

Acute Appendicitis; Abdominal Pain (AP); Diagnostic Laparoscopy; Laparoscopic Appendectomy; Neoplasms

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Normal diagnostic laparoscopy group

The appendix is left in situ, e.g. not resected and no other surgical procedure is needed to treat other diseases, identified through both the nationwide Danish National Patient Register and Danish Pathology Data Bank

Normal diagnostic laparoscopy

Intervention Type: PROCEDURE

The appendix is left in situ e.g., not resected and no other surgical resection is needed to treat other diseases

Negative appendectomy group

The appendix is resected but is without histopathological inflammation and no other surgical resection is needed to treat other diseases, identified through both the nationwide Danish National Patient Register and Danish Pathology Data Bank

Negative appendectomy

Intervention Type: PROCEDURE

The appendix is resected but is without histopathological-confirmed inflammation and no other surgical resection is needed to treat other diseases

Interventions

Normal diagnostic laparoscopy

The appendix is left in situ e.g., not resected and no other surgical resection is needed to treat other diseases

Intervention Type: PROCEDURE

Negative appendectomy

The appendix is resected but is without histopathological-confirmed inflammation and no other surgical resection is needed to treat other diseases

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• All ages and sexes
• Undergoing laparoscopic surgery for suspected appendicitis from 2005 to 2021
• Resected appendix without inflammation e.g., without appendicitis

Exclusion Criteria

• Previous resection of the appendix (e.g., previous appendectomy, or resection of the gut including the appendix before January 1, 2005) based on data from surgical codes in the Danish National Patient Register
• Unable to be tracked in the Danish registers, such as a replacement personal identification number, or for those not residing in Denmark based on data from the Civil Registration System
• Diagnostic codes indicating appendix cancer at index surgery (C181), thus, not operated for suspected appendicitis
• Laparoscopic appendectomy converted to open surgery or other surgical procedures conducted contaminated with laparoscopic appendectomy, indicated a need for other surgical interventions because of disease

• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Danish Institute for Public Health

OTHER

Sponsor Role: collaborator

Herlev Hospital

OTHER

Sponsor Role: lead

Responsible Party

Siv Fonnes

Researcher, MD, PhD

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Siv Fonnes, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Herlev Hospital

Other Identifiers

HEH-SF-03

Identifier Type: -

Identifier Source: org_study_id