This retrospective observational study examined a consecutive cohort of patients aged 70 years or older with acute cholecystitis (ICD-10 Codes: K81, K82) who were admitted between May 2021 and May 2022 at Doctor Balmis General University Hospital, Alicante, Spain. Patient care followed the established standard protocols of the hospital. Informed consent was not obtained from the patients due to the retrospective nature of the study. The study protocol adhered to the ethical guidelines of the 1975 Declaration of Helsinki (6th revision, 2008). This study was approved by the Research Ethics Committee of the Dr. Balmis Hospital (CEIm: PI2024-078). The study design and analysis complied with the STROCCS Reporting Guidelines for Cohort Studies (42).

Patients meeting any of the following criteria were excluded from the study: (a) history of prior cholecystitis episodes, ERCP, or previous cholecystostomy; (b) concurrent diagnosis of pancreatitis or any terminal illness with a life expectancy of less than one year; (c) acute cholecystitis diagnosed as a secondary condition, or in conjunction with acute pancreatitis, cholangitis, bile duct disorders, or gastrointestinal malignancy; (d) acute cholecystitis discovered incidentally during another surgical procedure, Mirizzi syndrome, or prior diagnosis of gallbladder cancer. Incidental gallbladder cancer was not an exclusion criterion. We intentionally did not include four patients who underwent EUS-guided gallbladder drainage during the index admission, as the small number of patients would have prevented a statistical analysis.

In addition to demographic data and past medical and surgical history, Charlson comorbidity index (CCI) (43), ECOG and Karnofsky performance status were recorded. The ASA score was used to ascertain patient's surgical risk. The definitive diagnosis of acute cholecystitis was graded according to the Tokyo guidelines. Duration of symptoms >72 h prior to admission was selected to categorize patients as it defines grade II in the Tokyo guidelines (5). Given that the Tokyo guidelines flowchart adds the coexistence of jaundice (total bilirubin >2 mg/dl) as one of the negative predictive factors in grade III acute cholecystitis, this laboratory value at admission was also selected as threshold to categorize patients (44). Laboratory values at admission used to define grades II and III in the Tokyo guidelines (i.e., creatinine >2.0 mg/dl, INR >1.5, platelet count <100,000/mm³, and white blood cell count >18,000/mm³) were selected as thresholds to categorize patients (5).

Supportive care consisted of intravenous hydration, analgesia utilizing acetaminophen or non-steroidal anti-inflammatory drugs, and administration of antibiotics (3). Percutaneous gallbladder drainage was carried out through either transperitoneal or transhepatic routes, accompanied by a radiological assessment prior to drain removal. In instances where surgery was deemed necessary, laparoscopic cholecystectomy was the preferred approach in most cases.

Additional procedures, hospital readmissions due to acute cholecystitis-related complications, and outpatient encounters throughout the initial year following the index admission were recorded. Additional procedures included delayed cholecystectomy, percutaneous or endoscopy-guided gallbladder drainage procedures, and ERCP performed to remove stones or sludge from the common bile duct. Readmission episodes attributed to acute cholecystitis complications, encompassing recurrence, cholangitis, liver abscesses, common bile duct stones, and biliary colic were analyzed. Throughout the one-year outpatient follow-up, both planned appointments and unplanned encounters were documented. The latter encompassed instances where patients presented with complaints or symptoms pertaining to acute cholecystitis.

The primary endpoints of the study were defined as follows: (a) additional procedures within the first year; (b) hospital readmissions within the first year attributable to biliary causes, and (c) outpatient encounters over the course of the first year, including both planned appointments and unscheduled visits.

Anonymized data was collected and managed using REDCap tools (REDCap®, Research Electronic Data Capture, University of Vanderbilt, Nashville, Tennessee, US) hosted at Asociación Española de Gastroenterología (AEG; https://www.redcap.aegastro.es) (45).

Descriptive statistics was used to analyze the demographic and baseline characteristics of the patients. Quantitative variables were presented as median and interquartile range (IQR), while categorical variables were expressed as absolute and relative frequencies. Group comparisons were performed using the Chi-square test or Fisher's exact test for categorical data, the T-test for parametric quantitative data, and the Mann–Whitney U test for quantitative non-parametric data. Although propensity score matching analysis has been used primarily for the comparison of two groups of subjects in observational studies, it has recently been considered for the analysis of more than two groups (46). However, due to the small number of subjects in this study, it was not possible to use it for more than two groups. Surgery was designated as the reference group for comparisons. Propensity score matching (1:1 optimal match) was performed using the MatchIt package for R software. The propensity score was determined via logistic regression, incorporating demographic and pre-procedure characteristics to mitigate the impact of selection bias, with a 0.1-caliper width employed. The procedure's impact was assessed by comparing outcomes (medians for continuous data, proportions for dichotomous data) following matching (47). Survival curves were generated utilizing the Kaplan–Meier method and subsequently compared using the log-rank test. P values of less than.05 were considered statistically significant. All analyses were performed using RStudio, version 1.2.5001 (Integrated Development for R. RStudio, Inc., Boston, MA, USA).

A cohort of 50 patients diagnosed with acute cholecystitis were included in the study. Among them, 21 patients were septuagenarians, while 29 were octogenarians or older. During the index admission, cholecystectomy was performed on nine patients (18%), while 19 patients (38%) received supportive care. Additionally, percutaneous gallbladder drainage was carried out in 22 patients (44%).

Patients who received supportive care exhibited higher ASA scores (ASA 1, 21.1%; ASA 2, 63.2%; ASA 3, 15.8%) compared to those who underwent cholecystectomy (ASA 1, 77.8%; ASA 2, 22.2%) (P = .02) (Table 1). Patients who underwent percutaneous gallbladder drainage exhibited higher Charlson Comorbidity Index scores (7.5 [4.3–9.8] vs. 5 [4–5], P = .04), poorer ECOG performance status (P = .04), and elevated ASA scores (ASA 1, 18.2%; ASA 2, 63.6%; ASA 3, 18.2%) when compared to patients who underwent cholecystectomy (P = .01) (Table 2).

A greater proportion of patients who received supportive care (47.4%) required additional procedures within one year compared to those who underwent cholecystectomy (0%) (P = .02) (Table 3, Figure 1). Furthermore, patients who received supportive care during their index admission required a higher number of additional procedures compared to those who underwent surgery (0 [0–1] vs. 0 [0–0], P = .02) (Table 3).

Similarly, significantly more patients undergoing percutaneous gallbladder drainage required additional procedures within one year (72.7% vs. 0%, p < 0.001) and experienced 1-year readmissions (50% vs. 0%, p = .01) compared to surgery (Table 4, Figure 1). In addition, the number of additional procedures (1 [0.25–1.75] vs. 0 [0–0], P < .001) and readmissions (0.5 [0–1] vs. 0 [0–0], P = .01) was significantly higher in patients who had percutaneous gallbladder drainage compared to those who had surgery during the index admission (Table 4).

Additional procedures performed and reasons for readmission by treatment modality are summarized in Supplementary Table 1. In the supportive care group, nine of the 19 patients required a total of 14 additional procedures. Of these, three patients required six readmissions, all due to recurrence of acute cholecystitis. In addition, a total of 26 additional procedures were required in 16 of the 22 patients who underwent percutaneous gallbladder drainage. Of these patients, 11 required 15 readmissions, primarily for recurrent acute cholecystitis.

One patient receiving supportive care and four patients undergoing percutaneous gallbladder drainage died during the follow-up period. Survival analysis was performed by index treatment modality within the baseline population. No survival differences were noted among the three index treatment modalities (Figure 2).

After propensity score matching, there were no demographic or preoperative differences between the groups (Tables 1, 2). A higher proportion of supportive care patients required additional procedures within one year compared to surgery patients (55.6% vs. 0%, P = .03) (Table 3, Figure 1). In addition, the median number of additional procedures (1 [0–1] vs. 0 [0–0], P = .01) and outpatient encounters (2 [1–3] vs. 1 [1–1], P = .01) was significantly higher in patients who received supportive care compared to those who underwent surgery (Table 3).

Similarly, patients undergoing percutaneous gallbladder drainage were significantly more likely to require additional procedures within one year (77.8% vs. 0%, P = .002) and to be readmitted within one year (55.6% vs. 0%, P = .03) than patients undergoing surgery (Table 4, Figure 1). In addition, median numbers of additional procedures (1 [1–2] vs. 0 [0–0], P = .002) and rehospitalizations (1 [0–2] vs. 0 [0–0], P = .01) were significantly higher in patients undergoing percutaneous gallbladder drainage than in those undergoing cholecystectomy (Table 4).

After propensity score matching, the specific types of additional procedures performed and reasons for 1-year readmission attributed to acute cholecystitis-related complications are shown in Supplementary Table 1. A total of seven additional procedures were required in five patients who received supportive care. Additionally, two patients required four readmissions, all related to recurring acute cholecystitis. Among those who underwent percutaneous gallbladder drainage during the index admission, seven patients required a total of 12 additional procedures, with five patients requiring 10 readmissions for recurrent acute cholecystitis and other reasons.

A laparoscopic approach was used in all patients who underwent cholecystectomy during the index admission. In contrast, two patients who had a delayed cholecystectomy after supportive care or percutaneous gallbladder drainage required an open approach or conversion to an open approach (Supplementary Table 2). No cases of common bile duct injury or need for reoperation were observed in either group.

There are several limitations to our study. First, it included retrospective data from a single center with a relatively small patient cohort. Second, only four patients underwent EUS-guided gallbladder drainage during the study period. Therefore, they could not be included in the statistical analysis. Third, a notable gap in this study is the lack of data on patient-reported outcomes, particularly quality of life. Research has shown that acute cholecystitis in the elderly population can have a profound impact on their perception of quality of life. Therefore, this aspect is of particular importance (2, 8, 32, 35, 51–53). Finally, statistical comparisons between variables were limited by the heterogeneous data collection for cholecystectomies performed during index and delayed admissions. Despite this, all index cholecystectomies were performed laparoscopically, whereas some delayed cholecystectomies began as open procedures or were converted to open. Notably, intense fibrosis around the common bile duct or adjacent viscera was observed in more than half of the delayed cholecystectomies.