Cholelithiasis remains one of the most common digestive system disorder that is still of  high medical and social importance due to its prevalence, the risk of complicated disease forms, ad significant burden on the surgical care provision system. The prevalence of cholelithiasis in European and American countries reaches 30.1%, and the prevalence in the Russian Federation is 10.0–12.0% [1]. The largest proportion of cases is found among the working-age population (40–69 years), which further underscores the socio-economic significance of timely surgical treatment for this category of patients. Among complicated cholelithiasis forms, of special importance are choledocholithiasis, acute cholangitis, and acute biliary pancreatitis associated with the risk of severe course and fatality [2].

Today, laparoscopic cholecystectomy (LC) is the main surgical method for treatment cholelithiasis and chronic calculous cholecystitis. The minimally invasive nature of the intervention, reduction of surgical trauma, reduction of the length of hospital stay, and earlier restoration of the patient’s activity create prerequisites for performing this procedure in the context of hospital-replacing technologies [3]. At the same time, the surgical approach minimally invasive nature itself is not a sufficient condition for reduction of the length of the patient’s hospital stay. The standardized patient selection criteria, unified patient routing approaches, trained surgical staff, capacity for postoperative monitoring, and a clearly defined mechanism for transferring the patient to the round-the-clock hospital (RCH) when clinically indicated are essential for sustainable implementation of “one day” surgery [4].

In international practice, a significant proportion of elective surgical procedures are performed on an outpatient or shortstay basis. According to the findings of the exploratory review study, the share of outpatient and short-stay surgery in advanced economies reaches 60.0–70.0%, which is associated with the development of short-stay units (SSUs), minimally invasive technologies, and multimodal perioperative approaches [5]. The implementation of such models is of particular importance for the Russian Federation, especially for large cities, since it makes it possible to redistribute patient flows, reduce the burden on round-the-clock surgical inpatient facilities, and increase the accessibility of elective care while maintaining clinical safety standards [6].

The implementation of organizational models for elective surgical care based on standardized minimally invasive interventions requires adequate training of the surgical team. Mastering laparoscopic techniques entails not only theoretical training but also the systematic development of endoscopic surgical skills: working with virtual simulators and training devices, practicing specific procedures under simulated conditions, performing standard interventions under the mentor’s supervision, followed by a transition to independent practice [7]. Such phased training creating the staffing prerequisites for the consistent performance of elective laparoscopic surgical procedures can be considered as a component of the organizational implementation of hospitalreplacing technologies.

Of special interest is the use of SSU for elective LC, since this intervention can be performed in the one day surgery format with the differentiated patient routing. In the retrospective study (2011), most laparoscopic cholecystectomy procedures were performed in outpatient settings, and more than 80.0% of patients were discharged within hours after surgery. Patients requiring a presumably technically complex intervention, or presenting with significant comorbidity or other high-risk factors were referred to the RCH, and if discharge on the day of surgery was not possible, the unplanned hospitalization was provided for [8]. Current data also reflect the sustained dominance of the laparoscopic approach and provide a basis for analyzing the further organizational elective surgical care transformation [9].

Despite the obvious organizational advantages of SSUs, there is still a lack of major studies in domestic literature evaluating the results of implementing this model for the provision of elective surgical care at the metropolitan level. The issues of combining three key components (standardization of laparoscopic technology, patient routing, and organizational measures to ensure safety while reducing the length of hospital stay) are poorly understood [10]. In this regard, the analysis of the experience of performing elective LC in a short-stay hospital is of scientific and practical interest for surgery and healthcare organization [11].

The study aimed to assess the role of hospital-replacing technologies when providing surgical care to patients with cholelithiasis within the framework of the retrospective observational trial.

METHODS

The retrospective observational study was based on the analysis of the aggregate data on the elective surgical care provision to patients with chronic calculous cholecystitis and the dynamics of performing LC for the years 2016–2025. The research material consisted of the Moscow City Health Department data on the number of patients with cholelithiasis and its complicated forms, the number of elective LC procedures and open cholecystectomy (CE) procedures performed, as well as the surgical care distribution across RCHs and SSUs. In addition, organizational materials reflecting the development of the short-stay unit network, changes in patient routing, the implementation of criteria for transfer to RCHs, and the results of practice-oriented training for surgeons in laparoscopic technologies were analyzed.

Patients, who underwent elective surgery in the RCH and patients treated in the SSU were considered as organizational comparison groups. Indicators for 2016–2025, including the number of elective LC procedures, the number of CE procedures, the number of patients treated in SSU, and the change in the average bed-day were analyzed to assess the dynamics of the implementation of hospital-replacing technologies.

Inclusion criteria for the clinical part of the study: patients over the age of 18, verified diagnosis of calculous cholecystitis, elective nature of surgical treatment, and availability of the informed consent. Non-inclusion criteria: emergency surgery; active cancer requiring specific treatment; severe decompensated somatic disorder corresponding to the American Society of Anesthesiologists (ASA) index ≥ 4 points; pregnancy and lactation. Exclusion criteria: patient's refusal to continue participation, transfer from the SSU to the RCH due to clinical indications, incomplete data in medical records.

The following indicators were analyzed to assess the organizational effectiveness: total number of elective interventions due to cholelithiasis; number of LC and CE procedures; number of patients treated in RCHs and SSUs; average bed-day; average length of the patient’s hospital stay (h); age distribution of patients; trends of the development of SSUs in the structure of the Moscow City Health Department.

Descriptive statistical analysis was the main data processing method. Quantitative indicators were presented as absolute values, percentage, mean values, and standard deviations when there were appropriate data in the source materials. For the time series, changes in the indicators were assessed on a year-by-year basis over the years 2016–2025. RCHs and SSUs were compared based on the available aggregate organizational indicators, including the number of patients treated, average bed-day, and average length of hospital stay.

RESULTS

In 2016–2025, the sustained transformation of the structure of elective surgical care for patients with cholelithiasis was reported in medical institutions of the Moscow City Health Department. According to the data presented, the total number of elective surgical interventions for cholelithiasis in the analyzed period was 99,907 cases. The bulk of surgical care was accounted for by LC procedures, while the share of CE procedures decreased consistently. The number of LC procedures increased from 8571 in 2016 to 12,681 in 2025, while the number of CE procedures decreased from 242 to 16, respectively. The above trend reflects consolidation of the aparoscopic approach as the dominant surgical method for the elective treatment of cholelithiasis in a metropolitan setting (fig. 1).

The development of the hospital-relplacing surgical care model took place against the background of expanding the application of laparoscopic technologies. In 2016, five SSUs of four specialties were operating in Moscow: surgical, gynecological, urological, and ophtalmological. The number of SSUs increased to 30 by 2025, this model was expanded to the adult and pediatric population and supplemented with new specialties, including maxillofacial surgery, otorhinolaryngology, traumatology and orthopedics, oncology, and purulent and vascular surgery. The SSU network development was accompanied by changes in patient routing and determination of the criteria for admission to the SSU or RCH.

A progressive increase in the SSU contribution in the structure of surgical care provision to patients with chronic calculous cholecystitis was reported. In 2016, a total of 8850 interventions due to chronic calculous cholecystitis were performed in RCHs, while 27 were performed in SSUs. In 2025, appropriate indicators were 7653 and 5075 cases. Thus, the number of interventions performed in SSUs increased more than 180-fold during the analyzed period, which suggests a significant redistribution of a portion of the patient flow for elective surgery to the hospital-replacing sector (fig. 2).

Comparison of patients with chronic calculous cholecystitis treated in 2025 in SSUs and RCHs revealed the differences in the age distribution and the length of hospital stay. The share of patients over the age of 70 in RCHs was 36.0%, while in SSUs it was 13.3%. In contrast, the share of patients aged 30–44 and 45–59 years was higher in SSUs: 22.1% and 32.1%, respectively, vs. 12.3% and 21.9% in RCHs. These data suggests that there is selective routing of patients based on age and, likely, overall clinical risk, which must be taken into account when interpreting differences between organizational forms of care provision.

In 2025, when treating patients with chronic calculous cholecystitis, an average bed-day was four bed-days in the RCH and one bed-day in the SSU. When adjusted for the patient's actual length of stay in the hospital, the average length of stay was 94.3 ± 21.3 h in the RCH and 16.2 ± 7.4 h in the SSU. The data obtained demonstrate a marked reduction in the length of hospital stay when using the hospital-replacing model for the elective surgical care provision (fig. 3).

The development of the SSU model was accompanied by changes in medical-economic standards for chronic calculous cholecystitis. Up to 2017, the standard length of hospital stay was five bed-days, in 2018–2025 it was three bed-days, and in 2025–2026 it was reduced to one bed-day. Such a trend reflecting the institutional consolidation of the hospital-replacing approach is consistent with the actual reduction of the length of patients’ hospital stay with elective LC.

Determination of the criteria for admission to the RCH has become essential for the SSU functioning. Such criteria include decompensation of chronic heart failure, body mass index ≥ 40.0 kg/m², the need for prolonged mechanical ventilation, referral to the intensive care unit, early period following an acute vascular event, decompensation of cancer, hematological disease or chronic renal failure, cardiac output ≤ 45.0% based on echocardiography data, hemoglobin levels ≤ 100.0 g/L, surgical procedure duration exceeding 3 h, decrease in hemoglobin levels by more than 20.0% of preoperative levels, no diuresis, use of renal replacement therapy, as well as the decision of the multidisciplinary team. The presence of these criteria allows one to consider the RCH as a backup safety contour for the implementation of the hospital-replacement model of surgical care.

DISCUSSION

The data obtained suggest a significant transformation of elective surgical care for patients with cholelithiasis in a metropolitan setting. In 2016–2025, LC became firmly established as the primary method of surgical treatment for chronic calculous cholecystitis, while the number of open CE procedures considerably decreased. This reflects not only the development of minimally invasive surgery, but also changes in the organizational model of elective surgical care provision. Similar approaches are described in the papers considering LC as the main surgical treatment method for symptomatic cholelithiasis [12, 13]. It is emphasized that the possibility of performing LC in the short-stay surgical unit is determined by not only minimally invasive nature of the intervention, but also proper selection of patients [14].

A significant increase in the SSU contribution to the healthcare system of Moscow was one of the main findings of the study. While such interventions were sporadic in 2016, by 2025, SSU had become a significant component of elective surgical care. This indicates the gradual redistribution of some patients from RCHs to the hospital-replacing sector. The feasibility of performing LC in the one-day surgery format, with organized patient selection and a standardized route, is also demonstrated [15]. However, the success of such approach is attributed exclusively to the consideration of factors capable of affecting the hospital stay length and the possibility of patient’s early discharge from the surgical hospital [14].

The increase in the number of functioning SSUs over the past decade has been accompanied by changes in patient routing, the training of surgical personnel, and the implementation of patient hospitalization criteria. That is why SSU should be not merely as the bed-day reduction, but as a distinct organizational model of elective surgical care. This is consistent with the data of the research considering the accelerated postoperative recovery programs as a comprehensive approach to the perioperative management of surgical patients [16]. It has been also shown that the minimally invasive approach itself is insufficient, and the surgical intervention outcome is largely dependent on the full implementation of the accelerated postoperative recovery protocol components [17].

Reduction of the average length of hospital stay in patients with chronic calculous cholecystitis from 94.3 ± 21.3 h in the RCH to 16.2 ± 7.4 h in the SSU is one of the most striking results of implementing the hospital-replacing model. However, such a difference should not be interpreted as direct proof of the SSU clinical superiority to the RCH. It is more appropriate to consider it as the result of patient pre-selection and the perioperative management organizational standardization. This is suggested by the differences in the age distribution of patients treated in RCHs and SSUs. The share of patients over the age of 70 was larger in RCHs, while patients of younger, working age prevailed in SSUs. Thus, patient pre-selection is considered in one paper as one of the basic requirements for successful outpatient surgery, including taking into account age characteristics [18]. Other authors emphasize that it is necessary to take into account not only age, but also comorbidities, functional status, and social conditions, in elderly patients [19]. This confirms the need for differentiated patient routing between the SSU and the RCH.

Availability of the clearly defined backup route for transferring the patient to the RCH is important for the safe SSU functioning. In the model presented, such a route is determined by transfer criteria, including decompensation of cardiovascular, renal diseases, cancer, or hematological conditions, high body mass index, decreased hemoglobin levels, an surgical procedure duration exceeding 3 h, the need for intensive care, and the decision of the multidisciplinary team. Thus, the importance of careful patient selection has been confirmed, and the association of risk factors with the delayed hospital discharge and unplanned readmission has been shown [20–22]. Furthermore, the SSU effectiveness should be assessed based on not only the length of hospital stay, but also the rate of complications, transfer to the RCH, readmission, and unplanned visits [23].

The data obtained are consistent with the general logic of the "one-day" surgery development, in which the minimally invasive nature of the procedure, postoperative course predictability, standardized patient selection, and the possibility of prompt response to complications are the key conditions. LC due to chronic calculous cholecystitis is more compliant with these conditions, that many other abdominal interventions, making it one of the surgical procedures most suitable for the implementation of hospital-replacing technologies in elective surgery.

Study limitations

The findings of the study should be interpreted considering a number of limitations. First, the analysis is based primarily on aggregate organizational data, which precludes a comprehensive assessment of individual clinical outcomes. Second, there are no data on the rate of postoperative complications, conversions, readmissions, transfers from the SSU to the RCH, and mortality in comparable groups. Third, the differences in age distribution between the RCH and SSU patients suggest possible effects of the selection bias. Fourth, external organizational factors associated with changes in the healthcare system operation during the COVID-19 pandemic could affect the elective surgical care trends in 2020–2021.

CONCLUSIONS

In 2016–2025, a sustainable model of elective surgical care provision to patients with cholelithiasis based on the predominance of laparoscopic cholecystectomy, SSU development, standardized patient routing, and a backup system for transfer to the RCH was formed in the metropolitan area. During the period analyzed laparoscopic cholecystectomy finally entrenched as the main surgical treatment method for cholelithiasis. The number of laparoscopic interventions increased by 48.0%, while the number of open cholecystectomy procedures decreased by 93.4%. Such a trend reflects not only the surgical care technological development, but also the enhanced system's organizational readiness to perform elective minimally invasive interventions with the reduced hospital stay length. SSU has become an important component of elective surgical care provision to patients with cholelithiasis. While such interventions in SSUs were sporadic at the beginning of the period analyzed, this approach accounted for approximately 39.9% of the elective surgical caseload for cholelithiasis by the end of the period. This indicates a marked redistribution of some of patients from round-the-clock hospitals to the hospital-replacing sector. The differences in the patients’ age distribution suggest the selective nature of patient routing and the need to account for baseline clinical risk when comparing organizational forms of care provision. The use of SSUs was associated with the considerable reduction of the hospital stay length. The average bed-days at the SSU were 75.0% lower compared to the RCH, and the actual length of the patient’s hospital stay was reduced by more than 80.0%. These data characterize SSU as a practically significant hospital-replacing form of performing elective laparoscopic cholecystectomy in the selected patients. However, the findings should not be interpreted as evidence of the SSU superiority to the RCH. The study based primarily on aggregate organizational data involves no comprehensive assessment of individual clinical outcomes. That is why it is more correct to consider the reported reduction of the length of hospital stay as the result of the selective patient selection, standardized patient pathways, and organizational perioperative process optimization. An analysis of individual patient data, considering the rate of postoperative complications, conversions, readmissions, transfer from the SSU to the RCH, mortality, as well as the patients' baseline clinical risk, is necessary for further evidencebased assessment of the model safety and efficiency. Such an approach will make it possible to move from describing the organizational transformation to the comprehensive clinical and organizational assessment of hospital-replacing technologies for elective laparoscopic cholecystectomy.