Impact of in-hospital delay on clinical and economic outcomes after laparoscopic appendectomy for acute appendicitis: a single-center retrospective cohort study

Abstract

Purpose

Optimal timing of appendectomy after hospital arrival remains controversial. Although early surgery has traditionally been recommended, recent evidence suggests short in-hospital delays may not adversely affect outcomes. This study evaluated the impact of hospital arrival-to-operation time on postoperative outcomes and hospital costs in patients undergoing laparoscopic appendectomy.

Methods

We conducted a retrospective study of 661 patients who underwent laparoscopic appendectomy. Patients were categorized into 3 groups according to the interval between hospital arrival and operation start: ≤6 hours (group 1), >6 to ≤12 hours (group 2), and >12 hours (group 3). Baseline characteristics, operative outcomes, postoperative complications, recovery parameters, and hospital costs were compared. Multivariable logistic regression was performed to assess the independent association between in-hospital delay and postoperative complications.

Results

Baseline demographic and clinical characteristics were comparable among groups, although American Society of Anesthesiologists classification and serum albumin levels differed slightly. The overall 30-day postoperative complication rates were similar (8.5%, 9.5%, and 10.0% in groups 1, 2, and 3, respectively; P = 0.848). Multivariable analysis showed that in-hospital delay was not independently associated with postoperative complications. No significant differences were observed in severe complications, readmission, mortality, time to oral water intake, soft diet initiation, length of hospital stay, or hospital costs (P = 0.529).

Conclusion

An in-hospital delay of >12 hours before appendectomy was not associated with increased postoperative complications, prolonged hospitalization, or higher hospital costs. These findings support flexible scheduling of laparoscopic appendectomy while maintaining safe clinical outcomes.

INTRODUCTION

Acute appendicitis remains one of the most common surgical emergencies worldwide [1]. Traditionally, prompt appendectomy has been emphasized to prevent disease progression and postoperative complications [2]. However, immediate surgery is not always feasible owing to operating room availability, staffing limitations, and prioritization of other emergency cases [3].

Recent studies have suggested that short in-hospital delays before appendectomy may be clinically acceptable, particularly in the era of advanced imaging, antibiotic therapy, and minimally invasive surgery [4,5]. Nevertheless, most studies have relied on a single time cutoff to define surgical delay, and it remains unclear whether these conclusions are consistent when the early in-hospital period is examined in greater temporal detail. Moreover, limited data exist regarding the economic impact of delayed appendectomy, despite increasing pressure to balance patient safety with efficient resource utilization.

Therefore, this study aimed to evaluate whether stratified in-hospital time intervals from emergency department presentation to operation start are associated with postoperative outcomes and medical costs in patients undergoing laparoscopic appendectomy.

METHODS

Ethics statement

This study was approved by the Institutional Review Board of Chuncheon Sacred Heart Hospital (No. 2024-05-007) and was conducted in accordance with the Declaration of Helsinki, and the requirement for informed consent was waived owing to the retrospective nature of the study.

Study design and patient population

This retrospective study evaluated the impact of in-hospital surgical delay on perioperative outcomes following laparoscopic appendectomy for acute appendicitis. Patients who presented to the emergency department of Hallym University Chuncheon Sacred Heart Hospital between January 2018 and June 2021 and subsequently underwent emergency laparoscopic appendectomy were screened for eligibility.

During the study period, 697 patients who underwent surgery for acute appendicitis were initially identified. After excluding patients who underwent open appendectomy or combined surgical procedures, those with concomitant right colonic diverticulitis, delayed diagnosis owing to initial misdiagnosis, and cases with incomplete clinical data, a total of 661 patients who presented to the emergency department were included in the final analysis (Fig. 1). The diagnosis of acute appendicitis was confirmed preoperatively using abdominopelvic computed tomography and ultrasonography. All procedures were performed by 7 experienced surgeons, each of whom had completed more than 200 laparoscopic appendectomies.

Fig. 1. Flow diagram of patient selection. Overall, 697 patients who underwent surgery for acute appendicitis during the study period were screened. After excluding patients who underwent open appendectomy, combined surgical procedures, delayed diagnosis, concomitant right colonic diverticulitis, or had missing data, 661 patients who underwent laparoscopic appendectomy were included in the final analysis. Patients were categorized according to the interval between hospital arrival and initiation of surgery. Group 1, ≤6 hours after hospital arrival; Group 2, >6 to ≤12 hours after hospital arrival; Group 3, >12 hours after hospital arrival.

Perioperative management and surgical timing

Following clinical confirmation of acute appendicitis, surgical scheduling was coordinated with the anesthesiology team. The interval between hospital arrival and the start of surgery was recorded for each patient and used as the primary exposure variable. For analytical purposes, patients were categorized according to this interval into 3 clinically relevant time windows: within 6 hours, between 6 and 12 hours, and beyond 12 hours after hospital arrival. Preoperative fasting was maintained for at least 8 hours for solid food and 6 hours for liquids whenever feasible. Intravenous antibiotics were administered at the time of diagnosis in the emergency department. A third-generation cephalosporin was used for uncomplicated appendicitis, while metronidazole was added in cases of suspected or confirmed complicated appendicitis. Antibiotics were continued during the preoperative waiting period when surgery was delayed. Laparoscopic appendectomy was conducted using either a single- or multi-port approach, according to the attending surgeon’s discretion. Decisions regarding trocar placement, ligation technique, drain placement, and wound closure were individualized based on intraoperative findings. Postoperatively, intravenous antibiotics were administered for 3 to 5 days in patients with complicated appendicitis, depending on the degree of intra-abdominal inflammation and the patient’s clinical condition. Patients with uncomplicated appendicitis did not routinely receive prolonged postoperative antibiotic therapy beyond perioperative prophylaxis. Oral intake was initiated with liquids following the return of bowel function and advanced to a soft diet as tolerated. Discharge was considered once patients achieved adequate pain control with oral medication, remained afebrile without signs of surgical site infection, and tolerated a soft diet.

Data collection and outcome assessment

Clinical data were retrospectively obtained from electronic medical records using a structured case report form. Recorded variables included demographic characteristics, comorbidities, American Society of Anesthesiologists (ASA) classification, laboratory findings at admission, timing variables related to symptom onset and surgery, intraoperative details, and postoperative outcomes. The severity of appendicitis was classified as uncomplicated or complicated based on intraoperative findings and pathological examination, with complicated appendicitis defined as gangrenous or perforated appendicitis with or without abscess formation or peritonitis. Postoperative complications occurring within 30 days were recorded and graded according to the modified Clavien-Dindo classification [6]. Specific complications were predefined to ensure consistency in data collection. The primary outcome of the study was the incidence of 30-day postoperative complications. Secondary outcomes included time to resumption of oral intake, length of postoperative hospital stay, readmission within 30 days, and total hospital cost. To evaluate the independent association between in-hospital delay and postoperative complications, a multivariable logistic regression analysis was performed. Variables considered clinically relevant or showing potential association in univariate analysis were included in the model, including age, body mass index (BMI), ASA classification, serum albumin level, and complicated appendicitis.

Statistical analysis

Continuous variables are presented as means ± standard deviations or medians with interquartile ranges, as appropriate. Comparisons of continuous variables among the 3 surgical timing categories were performed using one-way analysis of variance for normally distributed data and the Kruskal-Wallis test for non-normally distributed data. Categorical variables are expressed as frequencies and percentages and were compared using the chi-square test or Fisher exact test, as appropriate. All statistical analyses were conducted using IBM SPSS Statistics ver. 22.0 (IBM Corp.), and a 2-sided P-value <0.05 was considered statistically significant.

RESULTS

Patient characteristics

Overall, 661 patients who underwent laparoscopic appendectomy were included in the analysis. Baseline demographic and clinical characteristics are summarized in Table 1. The distributions of age, sex, BMI, WBC count, neutrophil count, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio were comparable across the 3 surgical timing categories. The proportion of patients with higher ASA classification differed among the surgical timing categories, with a higher frequency of ASA class III–IV observed in patients with longer in-hospital delays (P = 0.034). Serum albumin levels showed a statistically significant difference among groups (P = 0.025); however, the absolute differences were small and unlikely to be clinically meaningful. A history of previous abdominal surgery was more frequent among patients who underwent earlier surgery (P = 0.047). The proportion of complicated appendicitis did not differ significantly among the surgical timing categories.

Table 1. Baseline characteristics of patients.

Values are presented as number, number (%), or median (interquartile range).

Group 1, ≤6 hours after hospital arrival; Group 2, >6 to ≤12 hours after hospital arrival; Group 3, >12 hours after hospital arrival.

ASA, American Society of Anesthesiologists; NLR, neutrophil-to-lymphocyte ratio; PLR, platelet-to-lymphocyte ratio.

Operative outcomes and surgical timing

Operative details are presented in Table 2. Operation time and estimated blood loss were similar regardless of surgical timing. No patient required conversion to open surgery. The distribution of single- and multiport laparoscopic approaches and the frequency of partial cecectomy did not differ significantly among the groups (P = 0.143 and P = 0.161, respectively). The interval between hospital arrival and operation start increased progressively across the surgical timing categories (P < 0.001), resulting in a corresponding prolongation of the total duration from symptom onset to surgery (P < 0.001). The duration from symptom onset to hospital arrival did not differ significantly (P = 0.080).

Table 2. Operative outcomes.

Values are presented as median (interquartile range) or number (%).

Group 1, ≤6 hours after hospital arrival; Group 2, >6 to ≤12 hours after hospital arrival; Group 3, >12 hours after hospital arrival.

MPLS, multiport laparoscopic surgery; SPLS, single-port laparoscopic surgery.

Postoperative outcomes

Postoperative outcomes are summarized in Table 3. The overall incidence of 30-day postoperative complications was comparable among the 3 surgical timing categories, with no significant difference observed (P = 0.848). The distribution of complications according to the modified Clavien-Dindo classification did not differ significantly. Severe complications, defined as Clavien-Dindo grade III or higher, were rare, and no 30-day mortality was observed during the study period. Time to resumption of oral liquid intake did not differ significantly among groups when analyzed using mean values (P = 0.458). Similarly, no significant differences were observed in time to resumption of a soft diet (P = 0.665), postoperative length of hospital stay (P = 0.950), or readmission rates (P = 0.782). Total hospital costs were comparable across the surgical timing categories, with no statistically significant difference identified (P = 0.529).

Table 3. Postoperative outcomes and hospital costs.

Values are presented as number (%), mean ± standard deviation, or median (interquartile range).

Group 1, ≤6 hours after hospital arrival; Group 2, >6 to ≤12 hours after hospital arrival; Group 3, >12 hours after hospital arrival.

ICU, intensive care unit; KRW, Korean won.

Multivariable analysis for postoperative complications

A multivariable logistic regression analysis was performed to evaluate the independent association between in-hospital delay and postoperative complications (Table 4). In-hospital delay was not independently associated with postoperative complications (6–12 hours: odds ratio [OR], 0.81; 95% confidence interval [CI], 0.39–1.70; P = 0.580; >12 hours: OR, 1.18; 95% CI, 0.61–2.27; P = 0.620). Lower serum albumin levels (OR, 0.27; 95% CI, 0.12–0.59; P = 0.001) and complicated appendicitis (OR, 2.51; 95% CI, 1.39–4.56; P = 0.002) were independently associated with postoperative complications, whereas increasing age was associated with a lower risk of postoperative complications (OR, 0.98 per year increase; 95% CI, 0.96–0.99; P = 0.022).

Table 4. Multivariable logistic regression analysis of postoperative complications.

CI, confidence interval; ASA, American Society of Anesthesiologists.

DISCUSSION

In this retrospective study, we evaluated the clinical and economic impact of in-hospital delay to laparoscopic appendectomy in patients with acute appendicitis. The principal finding of this study is that postponement of surgery beyond 12 hours after hospital arrival was not associated with an increased risk of postoperative complications, prolonged hospitalization, or higher medical costs. These findings suggest that moderate in-hospital delays may be clinically acceptable in selected patients undergoing laparoscopic appendectomy.

Traditionally, early appendectomy has been advocated to prevent disease progression and reduce postoperative morbidity. Several earlier studies reported higher complication rates with delayed surgery, particularly in cases of perforated appendicitis or prolonged symptom duration [7,8]. However, more recent evidence has challenged the necessity of immediate surgical intervention in all patients. Advances in diagnostic imaging, perioperative antibiotics, and minimally invasive surgical techniques have contributed to improved outcomes, even when surgery is not performed immediately after presentation [9,10,11].

Recent large-scale studies have focused on the safety of delayed appendectomy using various time thresholds. Bhangu et al. [12] demonstrated that short delays after hospital admission did not increase the risk of perforation or postoperative complications in adults with acute appendicitis. Similarly, van Dijk et al. [13] reported that appendectomy timing could be safely individualized based on patient risk profiles rather than adhering to rigid time-based mandates. Our findings are consistent with these reports and extend them by specifically examining the interval between hospital arrival and operation start, a factor that is directly influenced by institutional workflow and resource availability.

In addition, previous studies, including single-center analyses and systematic reviews, have suggested that surgical timing is often influenced by institutional workflow, including operating room availability and staffing during nights or weekends, without necessarily compromising patient outcomes [14,15].

Importantly, our study demonstrated that overall postoperative complication rates remained comparable despite progressively longer in-hospital delays. Severe complications were rare, and no difference in 30-day mortality was observed. Although minor differences in serum albumin levels were noted among timing categories, these variations did not translate into clinically meaningful differences in postoperative outcomes. Furthermore, multivariable logistic regression analysis adjusting for age, BMI, ASA classification, serum albumin level, and complicated appendicitis confirmed that in-hospital delay was not independently associated with postoperative complications. Instead, lower serum albumin levels and complicated appendicitis were identified as significant predictors of postoperative complications. Interestingly, increasing age was associated with a lower risk of postoperative complications in the multivariable analysis. This finding may reflect differences in inflammatory response or perioperative management between younger and older patients. However, given the relatively low overall complication rate, this association should be interpreted cautiously.

Notably, patients in the delayed surgery group had a higher proportion of ASA class III–IV, indicating a greater burden of comorbidities and higher baseline perioperative risk. Despite this unfavorable risk profile, postoperative complication rates did not increase with longer in-hospital delays. This finding suggests that surgical postponement in these patients may have provided an opportunity for careful preoperative assessment and optimization, rather than reflecting suboptimal or delayed care. In this context, in-hospital delay should not be viewed solely as a negative surrogate for disease progression or system inefficiency, but rather as a deliberate and clinically appropriate strategy to stabilize higher-risk patients before surgery. The absence of increased complications despite higher ASA scores supports the concept that short-term, clinically justified delays, when accompanied by appropriate perioperative management, may mitigate surgical risk rather than exacerbate it.

Functional recovery parameters were likewise unaffected by surgical timing. These findings suggest that postoperative recovery following laparoscopic appendectomy is influenced more by disease severity and perioperative management than by the precise timing of surgery within the first 24 hours after hospital admission.

An additional strength of this study is the inclusion of hospital cost analysis, which has been insufficiently addressed in previous studies. Despite concerns that delayed surgery may increase resource utilization, we found no significant difference in total hospitalization costs across surgical timing categories. This finding has important implications for healthcare systems facing increasing demands on operating room availability and staffing, particularly during nights and weekends. Allowing flexibility in surgical scheduling for stable patients may facilitate more efficient resource allocation without compromising patient safety. Concerns regarding increased healthcare costs associated with delayed surgery have also been raised; however, prior studies reported no significant increase in overall hospitalization costs, which is consistent with our findings [16]. It should also be noted that this study was conducted in South Korea, where appendectomy is commonly reimbursed under a diagnosis-related group–based payment system. Therefore, the limited variation in hospital costs observed in this study may partly reflect the characteristics of this reimbursement structure.

Some limitations of this study should be acknowledged. First, the retrospective design introduces the possibility of selection bias, as surgical timing was influenced by clinical judgment and institutional factors rather than random assignment. Second, this study was conducted at a single center, which may limit the generalizability of the findings to other healthcare settings. Third, although we adjusted comparisons using appropriate statistical methods, unmeasured confounding factors, such as subtle differences in disease progression or surgeon decision-making, cannot be entirely excluded. In addition, the relatively low overall complication rate in our cohort may have limited the statistical power to detect small absolute differences between groups; therefore, the findings should be interpreted as indicating no statistically significant association rather than definitive equivalence between surgical timing strategies.

Despite these limitations, this study provides clinically relevant evidence supporting the safety of flexible surgical timing for laparoscopic appendectomy in acute appendicitis. Our findings suggest that rigid requirements for immediate surgery after hospital arrival may be unnecessary in hemodynamically stable patients and that individualized scheduling based on clinical condition and resource availability is a reasonable approach.

In conclusion, among patients undergoing laparoscopic appendectomy for acute appendicitis, delays in surgery after hospital arrival were not associated with increased postoperative complications, prolonged hospitalization, or higher medical costs. These findings suggest that laparoscopic appendectomy can be safely performed within a flexible time frame after hospital arrival in hemodynamically stable patients, allowing adequate time for clinical assessment and perioperative optimization, and efficient use of hospital resources, without compromising patient outcomes.