Risk Factors for Necrotic Cholecystitis During COVID-19 Pandemic.
Risk Factors for Necrotic Cholecystitis During COVID-19 Pandemic.
Gangrenous cholecystitis is the most common complication of acute cholecystitis.

 Preliminary data showed that COVID-19 patients have a high risk to present necrotic
 cholecystitis.

 The Cholecystitis under COVID-19 pandemic WSES (ChoCO-W) study aims to investigate risk
 factors and high-risk patients to develop necrotic cholecystitis during this pandemic and
 their management.
Background:

 Gangrenous cholecystitis is the most common complication of acute cholecystitis affecting
 around 15% (range 2-30%) of patients and it occurs as a result of ischemia with necrosis of
 the gallbladder wall [1].

 It is related to an increased mortality rate (mortality rate ranging between 15 and 50%)
 compared with non-necrotic acute cholecystitis[2].

 Retrospective studies that investigated risk and predictive factors related to gangrenous
 cholecystitis showed that males, older patients with diabetes, coronary artery disease, and
 other comorbidities are at risk to present with gangrenous cholecystitis. [1-3] Another study
 identified longer delay time prior to hospital admission and low white blood cell count as
 independent risk factors affecting mortality and indicated the presence of diabetes mellitus,
 higher blood levels of aspartate aminotransferase, alanine aminotransferase, alkaline
 phosphatase and total bilirubin, pericholecystic fluid in abdominal ultrasonography, and
 conversion from laparoscopic surgery to open surgery as risk factors increasing mortality [2]
 In any case, the treatment of GC is similar to that of patients with AC but in the presence
 of GC, cholecystectomy can be difficult because of adhesions, insufficient anatomic control,
 complications like bleeding, and injury to bile ducts.

 There is high variability in the reported conversion rate to be 30% to 50% [4], down to 8.7%
 [5]. These results are probably due to a careful preoperative selection of patients for
 laparoscopic cholecystectomy and early surgery [6].

 Hunt et al [7] reported decreased morbidity and mortality rates with the implementation of
 laparoscopic cholecystectomy for GC.

 Onder et al [2] showed that mortality was higher in cases in which conversion to open surgery
 occurred.

 Recently, many authors reported necrotic and perforated cholecystitis as the most common
 complication of COVID-19 pneumonia [8-9-10].

 A recent multi-society position paper suggested to consider percutaneous drainage of the
 gallbladder after the failure of conservative therapy with antibiotics but highlighted that
 advanced age, or other factors of higher COVID-19 risk, cannot be regarded as sufficient to
 indicate this alternative treatment except in real conditions of the impracticability of
 cholecystectomy [11].

 In the lack of evidence and guidelines about the management of a patient with acute
 cholecystitis during COVID-19 pandemic, laparoscopic cholecystectomy, at most preceded by
 percutaneous trans-gallbladder drainage (PTGBD) in high surgical risk patients, remains the
 gold standard for the treatment of acute cholecystitis on COVID-19 patients, with high
 morbidity rate and length of hospital stay that increases the risk of spreading the virus
 among health care staff and negative COVID-19 patients.

 The study aims to evaluate the incidence and mortality of necrotic cholecystitis among Covid
 (+) patients under the COVID-19 pandemic, to improve their management and to confirm that
 COVID-19 infection is a risk factor for necrotic cholecystitis; to assess the management of
 acute cholecystitis during COVID-19 pandemic.

 The rationale for the trial:

 -  Investigate the risk factors to develop necrotic cholecystitis under the COVID-19
 pandemic;

 -  Evaluate the management of acute cholecystitis focusing on treatments and outcomes of
 the operative or non-operative management in COVID (+) and COVID (-) patients to improve
 outcomes, decreasing morbidity and mortality rates related to emergency setting and
 high-risk patients;

 -  Confirm that COVID-19 disease is a risk factor for necrotic cholecystitis.

 Objectives:

 Evaluate the incidence of necrotic cholecystitis during the COVID-19 pandemic among Covid
 patients; Evaluate the prevalence of necrotic cholecystitis in patients presenting with acute
 cholecystitis during the COVID-19 pandemic; Evaluate the risk factors for necrotic
 cholecystitis in COVID-19 patients and negative ones.

 Confirm the hypothesis that COVID-19 infection is a risk factor for necrotic cholecystitis;
 Evaluate the clinical outcomes of early (<72h from the onset of symptoms) versus delayed
 (>72h from the onset of symptoms) cholecystectomy, and of a non operative management
 according to the WSES international guidelines (2020) for the management of calculus
 cholecystitis and Tokyo severity classification for cholecystitis, in terms of mortality and
 morbidity.

 Primary endpoints To evaluate the prevalence of necrotic cholecystitis among patients
 admitted for acute cholecystitis during the Covid-19 pandemic; The incidence of necrotizing
 cholecystitis in the cohort of COVID-19 positive patients; To assess mortality due to
 necrotic cholecystitis during the Covid-19 pandemic among Covid-19 infected patients

 Secondary endpoints To investigate the risk factors for necrotic cholecystitis in patients
 admitted with diagnosis of acute cholecystitis and in the cohort of Covid-19 patients; to
 investigate if the COVID-19 infection is a risk factor to present necrotic cholecystitis; to
 assess the management of acute cholecystitis during Covid-19 pandemic and the role of non
 operative management strategy and operative management.

 Study Design:

 International Observational Prospective Cohort Study.

 Study population:

 All adult patients admitted to the surgical department with a diagnosis of acute
 cholecystitis (with and without necrotising cholecystitis).

 Inclusion criteria Patients of all age and sex admitted in the emergency department for acute
 cholecystitis, aged >=18 years old.

 Exclusion criteria Patients aged< 18 years old.

 Period April 2021-September 2021

 Data collection All epidemiological, clinical, surgical and follow up data will be collected
 on an online case report form.

 Sample size calculation This is an explorative study and data will be used to investigate
 risk factors, prevalence of necrotic cholecystitis among patients admitted with diagnosis of
 acute cholecystitis during COVID-19 pandemic, and the specific characteristics behind the
 choice between early cholecystectomy, delayed cholecystectomy, radiological drainage of the
 gallbladder and medical treatment (antibiotics) in an emergency setting.

 We calculated the sample size by considering the incidence of necrotic cholecystitis reported
 in literature which corresponds to a range of 2-30%. Taking into account the mean between the
 2 values, and in the lack of data on the incidence of necrotic cholecystitis in Covid
 patients, that we assumed to be double the incidence of necrotic cholecystitis in non-Covid
 population, with an alfa risk estimated error equal to 0.05, the study population will be
 composed of 2 cohorts of 111 patients

 Statistical analysis This is a study evaluating the prevalence of necrotic cholecystitis
 among patients admitted for acute cholecystitis during COVID-19 pandemic and the incidence of
 necrotic cholecystitis in Covid (+) patients. An univariate and multivariate analysis of each
 scheduled parameter will be carried out. In the statistical analysis, the investigator will
 differentiate data by cohorts (Covid (-) and Covid (+) patients) and gender. The main aim of
 this study is to assess the management of all patients having acute cholecystitis during
 COVID-19.

 Primary endpoints:

 In hospital mortality among patients with acute necrotic cholecystitis In hospital mortality
 among Covid-19 patients presenting with acute necrotic cholecystitis

 Secondary endpoints To assess the risk factors for necrotic cholecystitis in Covid+ patients;
 To evaluate the management of acute cholecystitis during the Covid-19 pandemic (medical
 treatment, surgical treatment, medical treatment and radiological drainage of the
 gallbladder); To confirm that COVID-19 infection is a risk factor for developing necrotic
 cholecystitis.

 Ethical Aspects This is an observational study. It will not attempt to change or modify the
 clinical practice of the participating physicians. All surgeons involved in the patient's
 recruitment will be included in the research authorship. This is an observational study, it
 will not attempt to change or modify the clinical practice of the participating physicians.
 The study will meet and conform to the standards outlined in the Declaration of Helsinki and
 Good Epidemiological Practices.

 Every clinical centre attending the study is responsible for Ethics Committee approval.

 All surgeons involved in the patients' recruitment will be included in the research
 authorship.

 Methods and assessments:

 Every clinical centre will be identified by a number assigned by the principal investigator
 before starting data entry. An online case report form will be available to collect data: the
 link for the access will be sent to the local investigator, to share with local
 collaborators.

 Safety Considerations There are no safety issues

 Informed consent This observational study will not attempt to change or modify the laboratory
 or clinical practices of the participating physicians, consequently informed consent will not
 be required. Each eligible patient for this study will be asked to sign a written consent to
 authorize the anonymous treatment of personal data, according to standard clinical practice.

 Data Management and Statistical Analysis Every local investigator is responsible for data
 entry. Prof. Fikri Abu-Zidan is the coordinator of statistical analysis.

 Expected Outcomes of the Study The aim of this study is to demonstrate the the correlation
 between necrotic cholecystitis and predisposition to thrombo-embolism in COVID-19 patients
 and that the patients presenting one or more risk factors for necrotic cholecystitis have to
 be managed operatively without long delay if fit for surgery.

 Dissemination of Results and Publication Policy The primary outcomes of the study will be
 presented at the World Congress of the World Society of Emergency Surgery in September 2021.
 The ChoCO-W study embraces corporate authorship and all collaborators that contribute to this
 study will form the ChoCO-W collaborative group. This group will co-author all publications
 in which ChoCO-W study data is used.

 Duration of the Project 2 years

 Ethics This is an observational study.

 Budget No budget study

 Financing and Insurance Not applicable
Inclusion Criteria:

 All patients presenting acute cholecystitis during COVID 19 pandemic, aged >=18 yo

 Exclusion Criteria:

 Patients presenting with acute cholecystitis aged <18 yo