Randomised feasibility trial of outpatient versus inpatient laparoscopic cholecystectomy for benign gallbladder disease (OUTchol): study protocol

Abstract

Introduction

Cholecystolithiasis is a common condition and most cases are asymptomatic. In symptomatic cases, gallstone disease results in hospitalisation and significant healthcare costs. Laparoscopic cholecystectomy is the standard treatment and is traditionally performed in an inpatient setting. Recent studies indicate that outpatient laparoscopic cholecystectomy may offer comparable safety and effectiveness yet the feasibility and cost-effectiveness are not conclusively defined.

Methods and analysis

This randomised-controlled, open-label feasibility trial will be conducted at two surgical centres in Thurgau, Switzerland. A total of 50 participants will be randomly assigned (1:1) to receive either outpatient or inpatient laparoscopic cholecystectomy. The primary endpoints include feasibility, safety and cost-effectiveness. Secondary endpoints assess mortality, postoperative complications, reinterventions and readmission rates, emergency department visits, pain, length of hospital stay, time to return to work and additional healthcare resource utilisation. The total follow-up will be 14 days.

Ethics and dissemination

The study has been approved by the local ethics committee and is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. Results will be disseminated through peer reviewed publications and conference presentations.

Trial registration number

DRKS00039001.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This is a prospective randomised controlled trial designed to compare outpatient versus inpatient laparoscopic cholecystectomy in a clinical setting.

• The study includes an assessment of feasibility, safety and cost-effectiveness within a defined healthcare system.

• The use of standardised care pathways for patients will provide for increased internal validity and reproducibility of the study.

• The strict inclusion criteria will only allow for a low-risk patient group to be enrolled in the study.

• The study is conducted within the Swiss healthcare system, and differences in organisational structures and reimbursement models may limit generalisability to other settings.

Introduction

Cholecystolithiasis refers to the presence of gallstones in the gallbladder, which is only considered a disease when symptomatic, known as gallstone disease. Gallstones are common, particularly in Western countries, with prevalence increasing with age and peaking between 50 and 60 years.¹ While most gallstones are asymptomatic, gallstone disease is a leading cause of hospitalisation and healthcare costs.¹ According to data provided by the Swiss Health Care Atlas, in the year 2023, a total of 17 810 laparoscopic cholecystectomies were performed, from which 1173 were performed in an outpatient setting.²

Inpatient laparoscopic cholecystectomy (LC) with planned postoperative hospital stay represents the current standard of care for elective treatment of benign gallbladder disease in Switzerland. In a PubMed search, we could find randomised controlled trials from other countries that show the safety of outpatient LC compared with an inpatient setting by demonstrating no difference in outcomes.³,⁹ The guidelines from the National Institute for Health and Care Excellence (NICE) recommend offering LC in an outpatient setting when the procedure is planned and the circumstances and patient’s clinical condition do not make an inpatient stay necessary.¹⁰ The British Association of Day Surgery (BADS) targets a rate of planned laparoscopic cholecystectomies performed in an outpatient setting at 75%, with this currently being achieved by just over 10% of trusts.¹¹ The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) also supports outpatient LC for appropriately selected patients.¹²

Although several randomised controlled trials have demonstrated the safety of outpatient LC, important uncertainties remain regarding its feasibility and economic implication within different healthcare systems due to different reimbursement structures and organisational pathways, so we cannot extrapolate the published data to the Swiss healthcare context. Therefore, this randomised clinical trial will address a relevant evidence gap by prospectively assessing the feasibility and safety of LC in an outpatient setting and demonstrate the non-inferiority of the outpatient intervention in the context of the Swiss healthcare system. Considering that a new pay rate system was introduced in Switzerland in 2026, we will also evaluate the possible superiority of cost-effectiveness for the healthcare system from the hospital perspective.

Methods and analysis

Study design

This is a randomised-controlled, open-label feasibility trial. The study will be conducted at two surgical centres of Cantonal Hospital Thurgau, Switzerland: Cantonal Hospital Frauenfeld, Pfaffenholzstrasse 4, 8501 Frauenfeld, Switzerland, and Cantonal Hospital Münsterlingen, Spitalcampus 1, 8596 Münsterlingen, Switzerland. These are secondary care hospitals that perform LC within routine surgical care pathways.

Patients receiving an elective LC will be 1:1 randomly allocated to be treated in an inpatient or an outpatient setting. Patients in the outpatient group will be discharged on the day of surgery and patients in the inpatient group will be discharged on the second postoperative day.

The study protocol adheres to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines,¹³ as detailed in online supplemental Table S1.

Participants

Participants will be recruited by consecutive sampling. All patients aged 18–65 years presenting to the surgical outpatient clinics of the participating centres and scheduled for elective LC for benign gallbladder disease will be screened for eligibility during the recruitment period. Screening will be performed by the treating physician or a delegated study physician using the predefined inclusion and exclusion criteria. The numbers of screened patients, eligible patients, patients approached for participation, patients providing consent, randomised patients and reasons for non-participation or exclusion will be recorded in a screening log.

If the patient provides written informed consent using the approved participant consent form, the patient will be randomised. An example of the participant consent form is provided as online supplemental material. No payment or compensation is given to study participants. No screening requirements are needed other than the indication for a LC due to cholecystolithiasis. Refusal or withdrawal of consent will not affect the treatment of the patient in any way. In such cases, the patient will undergo LC according to the centre’s standard inpatient procedure.

Inclusion criteria

Patients of at least 18 years old with an upper age limit of 65 years who were scheduled for elective LC due to benign diseases and who have signed the informed consent for participation.

Exclusion criteria

• Previous history of acute cholecystitis or pancreatitis.

• Clinical or radiological suspicion of choledocholithiasis.

• Suspicion of gallbladder or bile duct malignancy.

• Patients with a calcified gallbladder.

• Body mass index greater than 35 kg/m².

• American Society of Anaesthesiologists (ASA) physical status ≥ III.

• Prior major abdominal surgery, defined as previous open abdominal surgery or complex laparoscopic procedures involving major intra-abdominal organ resection (eg, colorectal resection, gastrectomy, pancreatic surgery or hepatectomy).

• Patients living more than 30 km from the hospital or without an adult caregiver to accompany them home and stay with them for at least 24 hours after discharge.

• Intake of opioid analgesics or steroids >5 mg/d for ≥7 days before surgery.

• Pregnancy or lactation.

• Participation in another concurrent interventional trial interfering with present trial.

• Suspected non-compliance, drug or alcohol abuse.

• Impaired mental state or language problems.

The criteria for the choice of this population are based on the available studies and guidelines.³,¹² With these inclusion and exclusion criteria, we aim to enrol a homogeneous, low-risk adult population undergoing elective LC for benign gallbladder disease. This selection aligns with the study’s core objective to evaluate the feasibility, cost-effectiveness and safety of outpatient treatment in comparison to standard inpatient care.

By including only patients with benign gallbladder disease and excluding those that were previously treated for an acute cholecystitis or pancreatitis, with clinical or radiological suspicion of common bile duct stones or suspicion of malignancy, the trial reduces confounding due to underlying disease severity. This ensures that outcome differences are due to the care setting rather than baseline clinical complexity. Limiting age to 18–65 and excluding patients with ASA>III helps ensure that participants have a predictably low perioperative risk, which is essential in an outpatient context. By excluding patients with prior open or complex laparoscopic abdominal surgeries or calcified gallbladders, we exclude the patients who have a baseline higher likelihood of conversion or intraoperative complications, which would require inpatient management and confound the safety endpoint. Outpatient management relies not only on medical factors but also on social and logistical support. Requiring patients to live within 30 km and to have an adult companion ensures safe same-day discharge and timely access to care if complications arise. Excluding patients with regular opioid or steroid use helps maintain consistency in pain and immune responses, which could otherwise affect complication rates, satisfaction and readmission rates. Patients with impaired mental status, substance abuse or language barriers are excluded to protect data quality and participant safety, especially as outpatient care places more responsibility on the patient and their environment.

Intervention

In both groups, patients will receive a standard LC. The only difference between the intervention and comparator groups relates to the perioperative care pathway and discharge strategy. LC will be performed using four trocars (two 12 mm - one periumbilical and one on the left hemiabdomen - and two 5 mm trocars - one subxyphoidal on the left side and one on the right hemiabdomen) after accessing the abdominal cavity and establishing a capnoperitoneum. The cystic duct and the cystic artery are prepared and, after critical view of safety is achieved, clipped using Hem-o-lok and cut. Afterwards, the gallbladder will be dissected from the liver bed and retrieved out of the abdomen using a retrieval bag. If spillage of bile or bleeding occurred, the abdomen will be rinsed with sodium chloride and the stones will be retrieved. The abdominal wall will be closed with Vicryl 3–0 (12 mm trocars) and all the skin incisions will be sutured. All procedures will be performed by board certified surgeons or by trainees under direct supervision.

After surgery, patients will be taken to the recovery room for observation where the first postoperative control will take place by the operating surgeon after about 2 hours. In the inpatient group, patients will be transferred to the surgical ward for postoperative observation. For the outpatient group, if there were no intraoperative complications as defined by this protocol, discharge will be considered once predefined discharge criteria are fulfilled. These include stable vital signs, adequate pain control with oral analgesia, the ability to tolerate oral intake, the ability to mobilise independently and the absence of clinically relevant postoperative complications such as bleeding or persistent nausea and vomiting. In case where there were intraoperative complications or in cases of insufficient postoperative pain control, postoperative nausea or vomiting or any clinical concern, they will be transferred to the surgical ward.

Intraoperative complications are defined as any unintended adverse event occurring between skin incision and skin closure requiring additional intervention or modification of the planned procedure. These include:

• Conversion to open surgery.

• Intraoperative bleeding with estimated blood loss > 500 mL.

• Bile duct injury.

• Visceral injury, defined as any unintended intraoperative injury to an intra-abdominal organ (eg, bowel, stomach or liver) that requires surgical repair or results in modification of the planned procedure.

• Vascular injury requiring repair.

• Intraoperative transfusion.

• Unplanned placement of abdominal drain due to intraoperative complication.

Adherence to the allocated care pathway will be promoted through standardised perioperative procedures and predefined discharge criteria. Adherence will be assessed by documenting whether participants were managed according to their allocated outpatient or inpatient pathway and whether any deviations occurred. All protocol deviations, including crossovers, will be prospectively recorded and considered in the analysis.

No restrictions are placed on concomitant care. Perioperative and postoperative management, including analgesia, antiemetic therapy and other supportive treatments, will be provided according to institutional standard of care in both study groups.

Primary endpoints

The primary endpoint of this study can be divided into feasibility, safety and effectiveness. The feasibility endpoint assesses the proportion of patients randomised to the outpatient group who are successfully treated according to the study protocol. Successful outpatient treatment is defined as discharge on the day of surgery without unplanned hospital admission or readmission within 14 days after the procedure.

The safety endpoint, based on the Comprehensive Complication Index (CCI)¹⁴ and analysed as a continuous variable, aims to demonstrate non-inferiority of safety of elective LC for cholecystolithiasis in an outpatient setting compared with the inpatient setting.

The effectiveness endpoint aims to evaluate the potential superiority of the outpatient approach in terms of cost-effectiveness from the hospital perspective, assessed by the hospital’s net financial balance, defined as the difference between reimbursed revenue and total hospital costs invoiced within 14 days after surgery, and analysed as a continuous variable.

Secondary endpoints

Secondary endpoints will be analysed according to their scale and distribution and are assessed at predefined postoperative time points as specified below. The endpoints include mortality with reason and possible association with trial intervention and postoperative complications according to the Clavien-Dindo¹⁵ classification within 14 days. Furthermore, we will assess reintervention, reoperation and readmission rate up to 14 days after surgery and the reason for this occurrence as well as data on the incidence of surgical site infection (according to Centers for Disease Control and Prevention definition).¹⁶ Pain on a numeric rating scale and postoperative nausea and vomiting will be evaluated at 4 hours, 48 hours and 14 days after LC. We aim to evaluate length of hospital stay and the reason for prolonged hospitalisation, defined by inpatient treatment longer than two nights after LC. The amount of visits to the emergency department after discharge and up to 14 days after surgery will be studied, including the reason for the visit to the emergency department. We also aim to compare time to return to work within 14 days after surgery and the costs of the two possible interventions for the hospital as well as the balance for each case for the hospital (costs for the healthcare system minus costs for the hospital).

All these parameters (primary and secondary endpoints) will be assessed postoperatively and systematically recorded during hospital stay and after discharge up to 14 days after the intervention according to the participant timeline.

Study timeline

The preparatory phase will take about 3 months. Since we will be recruiting patients for 10 consecutive months, we estimate the time from first patient in to last patient out at approximately 11 months with a total duration of the trial at 16 months. We plan to enrol the first participant in February 2026, whereby the last participant will be enrolled during November 2026. Data analysis, writing the scientific paper and submission to publication in a peer-reviewed journal is scheduled to take place between January and April 2027.

Participant timeline

Visit 1: procedures prior to surgery

During the baseline visit, a study physician will perform a pre-screening to assess general eligibility. If the patient appears suitable, the study physician will provide detailed verbal and written information about the trial. Informed consent will then be obtained. After consent, a full verification of inclusion and exclusion criteria is performed to confirm study eligibility. The participant’s medical history, relevant comorbidities, current medication and demographic characteristics are documented in the case report form. Baseline laboratory values and any required preoperative assessments are collected according to the study protocol. Once eligibility is confirmed, the patient will be randomly assigned to one of the study arms and scheduled for the surgical intervention. The randomisation procedure will be documented, and the participant will receive instructions regarding the next steps until the day of surgery.

Visit 2: day of surgery

Intraoperative procedures

Patients in both groups will receive a LC as described in the section Intervention.

Postoperative procedures

After surgery, patients will be taken to the recovery room for observation where the first postoperative control will take place by the operating surgeon after about two to four hours.

In the inpatient group, the patient will be transferred to the surgical ward for postoperative observation.

In the outpatient group, if there were intraoperative complications or too much postoperative pain or nausea, the patient will crossover to inpatient management. For all other patients in the outpatient group, the patient will be prepared for discharge from the hospital. This includes:

• Instructions regarding warning signs and how to react in such situations.

• Confirmation that a responsible adult will accompany them and remain present for at least 24 hours after discharge.

• Provision of emergency contacts.

• Confirmation of follow-up calls.

Visit 3: second postoperative day

Endpoints will be assessed on site for inpatients, or by phone for outpatients - unless presenting on site or readmitted.

Visit 4: assessment of endpoints 14 days after surgery

Endpoints will be assessed by phone for both inpatients and outpatients - unless presenting on site or readmitted.

A list with all study visits and contact with the participants, including assessment of endpoints, can be found in table 1.

Table 1. Summary of all the visits during the study.

	Visit 1	Visit 2	Visit 3	Visit 4
	Prior to surgery	Day of surgery	POD 2	POD 14
	Screening (consultation hour)		Telephone or ward	Telephone
Informed consent	x
Eligibility criteria	x
Baseline data	x
Randomisation/allocation	x
Intervention		x
Assessment of endpoints		x	x	x

POD, postoperative day.

Statistical analysis and sample size

This randomised controlled trial compares outpatient and inpatient LC with respect to three primary endpoints: feasibility, cost-effectiveness and patient safety. For the primary endpoints, the primary analysis set is the per-protocol population and outcomes will be analysed descriptively. For the safety and cost-effectiveness endpoints, an intention-to-treat and an ‘as treated’ analysis will be performed additionally. Outcomes will be analysed using exploratory comparative statistical methods. For the per-protocol analysis, only the patients who completed the intervention as initially planned will be analysed. For the ‘as treated’ analysis, all patients will be analysed as they were treated, irrespective of the originally allocated group. Patients who withdraw their consent prior to surgery or during the follow-up period will be excluded from the analysis.

Feasibility will be measured as the number of patients who were successfully treated in an outpatient setting according to this protocol compared with the number of screened, included and randomised patients of the outpatient group. The rates will be given using descriptive statistics with 95% CIs.

In addition to the feasibility of outpatient management, recruitment feasibility will be assessed. Recruitment outcomes will include the number of patients screened, the number fulfilling eligibility criteria, the number approached for participation, the number providing informed consent, the number randomised, the recruitment rate per month and per centre, and reasons for exclusion or non-participation.

Cost-effectiveness will be evaluated using the hospital’s net financial balance within 14 days after surgery, defined as the difference between reimbursed revenue and total invoiced hospital costs, and analysed as a continuous variable. Costs between groups will be compared using standard statistical methods appropriate to the distribution of the data. A descriptive p-value will be calculated and compared with a significance level of p<0.05.

Safety will be assessed using the CCI, which reflects the severity and number of postoperative complications within 14 days. Although this is primarily a feasibility trial and no confirmatory hypothesis testing is planned, we considered the implications of a non-inferiority margin of 4 points on the CCI for the safety endpoint. This margin reflects a clinically acceptable difference in postoperative morbidity between outpatient and inpatient LC.

Based on our in-house surgical database, the SD of the CCI in similar patient populations is approximately seven points. Assuming a significance level of 5% and aiming for a power of 80%, a total of 76 patients would be required for a formal non-inferiority analysis. However, given the feasibility nature of the trial and its limited sample size, a prospective formal sample size calculation was not performed. Instead, we plan to conduct a post-hoc power calculation for the safety endpoint based on the collected trial data. This approach aligns with the primary goal of assessing procedural feasibility and generating exploratory evidence on safety and cost-effectiveness, rather than delivering confirmatory statistical conclusions.

Based on the available literature, a sample size of about 50 patients should be sufficient to draw reliable and ethically sound conclusions about the feasibility of same-day discharge following elective LC. A formal sample size calculation for superiority of costs of the outpatient setting would presumably lead to a very low necessary sample size, while a formal sample size calculation for non-inferiority of the safety endpoint would lead to a very high necessary sample size. Therefore, we waive a formal sample size calculation, knowing that the result of the primary cost-effectiveness and safety endpoint will not be confirmatory.

With 50 randomised patients and approximately 25 patients allocated to the outpatient group, estimates of outpatient feasibility will be accompanied by 95% CIs. These intervals will be interpreted descriptively and are expected to provide sufficient precision for planning a future definitive trial, while recognising that they will not provide confirmatory evidence. For example, if 20 of 25 patients in the outpatient group are successfully managed as outpatients, the estimated feasibility proportion would be 80%, with an exact 95% CI of approximately 59% to 93%.

Secondary endpoints will be summarised and analysed using appropriate statistical methods. Categorical variables will be reported as frequencies and percentages, and continuous variables as means with SD or medians with range, depending on distribution. Group comparisons will be performed using χ² or Fisher’s exact tests for categorical data, and t-tests or Mann–Whitney U tests for continuous data, as appropriate.

Handling of missing data and drop-outs

Missing data will primarily be assessed descriptively, including the amount, timing and pattern of missingness for each outcome. As missing data are themselves an important feasibility outcome, no formal multiple imputation will be performed for the primary descriptive analyses. Exploratory sensitivity analyses using best-case and worst-case assumptions may be conducted for selected outcomes if relevant. If the patient withdraws the informed consent or drops out, there will be no replacement. All patients, including patients who crossover from outpatient to inpatient, will be included in the final analysis.

Withdrawal and discontinuation

Subjects may be withdrawn from the trial at their own request or at the request of the legal representative. The data and samples collected up to that point will still be evaluated in encrypted form. After the evaluation, the data will be anonymised. The key allocation will be destroyed, thus the data are not traceable afterwards.

Randomisation and allocation concealment

Patients scheduled for elective LC will be screened and, if eligible, enrolled consecutively by investigators after patients give their written informed consent. Patients will be randomised to the inpatient or outpatient group according to a concealed, computer-generated randomisation sequence using variable block sizes of 4, 6 and 8. The randomisation sequence will be generated by an independent person not involved in patient recruitment, eligibility assessment or outcome assessment. Allocation will be performed by a subinvestigator after confirmation of eligibility and written informed consent. The allocation sequence will remain concealed until the point of assignment. The number of patients is focused on the feasibility endpoint. Therefore, we will recruit patients to the trial for 10 months. We estimate that we will be able to include about 50 patients within 10 months. The number of patients will be identical between groups for both study sites. Due to the nature of the intervention, blinding of participants and treating clinicians is not feasible. This trial is therefore conducted as an open-label study.

Adverse events

This is a surgical trial and safety will be measured throughout the trial. If there is a major complication (defined as Clavien Dindo grade≥III) in the outpatient group within 48 hours, a safety review will be initiated. The principal investigator will assess the event and the overall safety profile of the trial and decide whether trial continuation is justified or whether protocol modifications or temporary suspension are required. The Ethics Committee will be notified via Business Administration System for Ethical Committees (BASEC) of these measures and of the circumstances necessitating them within 7 days. However, other surgical complications will not lead to interruption and no additional reporting will be performed.

Data recording and source data

Data will be collected prospectively using predefined electronic case report forms (eCRF). Data will be captured via a secure browser-based electronic system with automated transfer from the institutional clinical information system, where applicable, and supplemented by manual entry by trained study personnel. Data will be pseudonymised, stored on institutional servers and subject to predefined quality control procedures. Cost data will be derived from hospital invoicing records. Data will be archived for 10 years after study completion and will be destroyed thereafter. If the project is discontinued, the data in the eCRF will be destroyed after 10 years.

Access to protocol and statistical analysis plan

This article describes the full trial protocol. The statistical analysis plan is integrated within the protocol and no separate statistical analysis plan document has been prepared. The final version of the protocol will be made publicly available through the trial registry and via journal publication.

Monitoring and registration

This investigator-initiated trial is sponsored by the Department of Surgery of the Cantonal Hospital Thurgau. Overall trial responsibility lies with the investigator. Given the low risk categorisation according to the Swiss Ordinance on Clinical Trials in Human Research (ClinO Art. 61, category A), the limited sample size and the short follow-up period, no formal trial steering committee, data monitoring committee, formal auditing or independent endpoint adjudication committee was established. Study oversight will be provided by the Clinical Research Coordination Unit of Spital Thurgau AG. The monitoring process will follow established internal guidelines in compliance with Good Clinical Practice (GCP) and applicable Swiss regulatory standards. Monitoring will be conducted by trained clinical research professionals with relevant qualifications in GCP, regulatory compliance and clinical data management. The monitors are independent of the investigative team and are familiar with the specific operational and documentation requirements of this trial. Monitors will be granted direct access to anonymised source data, medical records and all relevant trial documents to fulfil their responsibilities. All data access will be logged and handled with strict confidentiality in accordance with data protection regulations. Monitoring activities include verification of eligibility criteria, informed consent procedures, source data verification and data quality checks and are conducted in accordance with GCP and local regulatory requirements. Serious adverse events and immediate safety measures are reviewed by the sponsor investigator and reported to the responsible ethics committee in accordance with applicable regulations.

Ethics and dissemination

This prospective study involving human participants will be performed in accordance with the ethical standards of the institutional and national research committee and with the 1964 Declaration of Helsinki¹⁷ and its later amendments or comparable ethical standards, the principles of GCP where applicable for surgical studies, the Human Research Act¹⁸ and the Human Research Ordinance.¹⁹ This study was approved by the local institutional review board (Project-ID 2025–02581, EKOS 25/225). Written informed consent will be obtained from all participants before inclusion in the study. Any protocol amendments will be documented, assigned a new version number and communicated to the relevant ethics committee and trial registries.

All study personnel will have adequate training in surgical studies and GCP. The independent study coordination at the Cantonal Hospital Thurgau will monitor at least one case per month for data credibility and at least five cases per month for existing general consent. The study coordination will report every finding to the primary investigator. For quality assurance, the Ethics Committee may visit the research sites. Direct access to the source data and all project-related files and documents must be granted on such occasions.

Data sharing

Anonymised individual participant data underlying the results of this trial may be made available on reasonable request to the corresponding author after publication of the primary results. Requests will be reviewed by the sponsor investigator and will be subject to approval by the responsible ethics committee and in compliance with institutional data protection regulations. Data will be shared for scientifically sound research proposals and only under a data sharing agreement. Statistical code and other study materials will not be shared.

Dissemination policy

The results of this trial will be disseminated through publication in a peer-reviewed scientific journal and presentation at national and international scientific meetings. A summary of the trial results will be entered into the relevant clinical trial registries in accordance with regulatory requirements. Study participants will be informed about the overall trial results on request. Authorship for all publications arising from this study will be based on substantial contributions in accordance with the International Committee of Medical Journal Editors criteria.

Discussion

LC is an established and widely practised procedure for treating benign gallbladder disease. While the traditional approach involves overnight inpatient observation for two nights, recent data suggest that outpatient surgery may offer comparable safety with additional benefits such as improved resource utilisation and greater patient convenience.

The main concern associated with outpatient LC is early discharge and the potential delay in recognising postoperative complications. However, such risks are minimised through strict inclusion and exclusion criteria such as limiting enrolment to low-risk patients, the use of standardised surgical techniques and clearly defined discharge criteria. Moreover, all outpatient participants must have a responsible adult to accompany them and remain present for at least 24 hours after discharge.

In addition, safety monitoring is built into the study design. Patients will be followed for 14 days postoperatively with clear protocols for managing complications and capturing safety outcomes through the CCI. Emergency contact options and follow-up calls will be in place to ensure patient support after discharge.

The benefits of this research include the potential to improve patient experience, reduce hospital stay without compromising safety and generate important data on cost-effectiveness and healthcare efficiency. In Switzerland, healthcare policy has increasingly emphasised the principle of ‘ambulatory before inpatient’ care in an effort to optimise resource allocation and control rising healthcare expenditures.²⁰ However, the safe implementation of ambulatory pathways requires robust prospective evidence, particularly for common surgical procedures such as LC. If outpatient management proves to be safe and feasible within a carefully selected patient population, the findings of this trial may contribute with valuable evidence to inform national healthcare strategies and support evidence-based expansion of ambulatory surgical care. In this context, the expected benefits to both individual participants and the healthcare system outweigh the minimal additional risks associated with earlier discharge.

The present trial has several methodological limitations. First, as a feasibility trial with a limited sample size, it is not powered to provide confirmatory evidence on non-inferiority of safety or superiority of cost-effectiveness. The analyses of safety and cost outcomes will therefore be exploratory and hypothesis-generating. Second, the open-label design is unavoidable because the allocated care pathway is evident to patients and clinicians, but it may introduce performance or reporting bias for patient-reported outcomes such as pain, nausea and return to work. Third, follow-up is limited to 14 days, which is appropriate for assessing early feasibility of same-day discharge, early postoperative complications, readmissions, emergency department visits, pain, nausea and early healthcare resource use, but may not capture late complications, longer-term recovery or longer-term cost consequences. Fourth, the strict inclusion and exclusion criteria are necessary for patient safety in an outpatient surgical pathway, but they limit the generalisability of the findings to older patients, patients with higher perioperative risk or those with relevant social or logistical barriers to same-day discharge.