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

Normal Diagnostic Laparoscopy Versus Negative Appendectomy in Patients With a Normal Appendix Undergoing Laparoscopic Surgery for Suspected Appendicitis: a Target Trial

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT06917612
Enrollment
20000
Registered
2025-04-08
Start date
2005-01-01
Completion date
2023-12-31
Last updated
2025-04-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

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

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

Interventions

PROCEDURENormal diagnostic laparoscopy

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

PROCEDURENegative appendectomy

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

Sponsors

Danish Institute for Public Health
CollaboratorOTHER
Herlev Hospital
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
Cancer in the appendix2 yearsHistopathologically verified cancer in the appendix (primary or metastasis) in the nationwide register the Danish Pathology Data Bank e.g., SNOMED morphology codes for cancer (M8\*\*\*\* or M9\*\*\*\*) in relation to the topography code of the appendix (T66000)
Appendix cancer2 yearsHistopathologically verified appendix cancer (primary) in the nationwide register the Danish Pathology Data Bank e.g., SNOMED morphology codes for cancer (M8\*\*\*\* or M9\*\*\*\*) in relation to the topography code of the appendix (T66000)

Secondary

MeasureTime frameDescription
Death2 yearsAll-cause death registered in the nationwide The Civil Registration System
Delay in diagnosis of cancer2 yearsTime from index normal diagnostic laparoscopy to histopathologically verified cancer in the appendix in the nationwide register Danish Pathology Data Bank, e.g., SNOMED morphology codes for cancer (M8\*\*\*\* or M9\*\*\*\*) in relation to the topography code of the appendix (T66000)
Any reoperation1 yearAny reoperations registered in the nationwide Danish National Patient Register
Abdominal reoperation1 yearAbdominal reoperations registered in the nationwide Danish National Patient Register e.g., with surgical codes KJ\*\*\* (gastrointestinal tract), KK\*\*\* (urological), or KL\*\*\*(gynecological)
Resected appendix2 yearsHistopathological record of an appendix in the nationwide register the Danish Pathology Data Bank e.g., record with topography code of the appendix (T66000) after index surgery, including subdivision of morphology codes into appendicitis, negative appendectomy, appendix cancer, and other
Readmission1 yearAny readmissions registered in the nationwide Danish National Patient Register, including subdivisions into diagnostic codes relating to different diseases

Other

MeasureTime frameDescription
Sensitivity analysis on comorbidity1 yearFor the secondary outcomes (death (2 years), reoperation, and readmission), confounding due to comorbidity will be explored for patients undergoing index surgery from January 1, 2010, and onwards, thus, allowing for calculating Charlson Comorbidity Index based data in the nationwide Danish National Patient Register from 5 years before to index surgery
Sensitivity analysis on umeasured confounding2 yearsFor the primary outcomes, unmeasured confounding e.g., due to preoperative imaging or perioperative macroscopic suspicion of cancer, will be addressed by calculating the E value
Subgroup analysis for outcomes at 2 years follow-up2 yearSubgroup analyses of all primary and secondary outcomes at the time-point 2 years after index surgery, including 75% to \<100% of the included participants in the target trial
Subgroup analysis for outcomes at 1 year follow-up1 yearSubgroup analyses of all primary and secondary outcomes at the time-point 1 year after index surgery, including 100% of the included participants in the target trial
Subgroup analysis for outcomes at 5 years follow-up5 yearSubgroup analyses of all primary and secondary outcomes at the time-point 5 years after index surgery, including as few as 75% of the included participants in the target trial

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026