Endoscopic Direct-vision Therapy vs. Antibiotics for Acute Uncomplicated Appendicitis: A Retrospective Cohort Study

Endoscopic Direct-vision Therapy vs. Antibiotics for Acute Uncomplicated Appendicitis: A Retrospective Cohort Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Endoscopic Direct-vision Therapy vs. Antibiotics for Acute Uncomplicated Appendicitis: A Retrospective Cohort Study Lipeng Chen, Feng Zhou, Qirun Cheng, Yuliang Feng This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9039444/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Apr, 2026 Read the published version in International Journal of Colorectal Disease → Version 1 posted 13 You are reading this latest preprint version Abstract BACKGROUND Endoscopic direct-vision appendicitis therapy (EDAT) is an emerging ultra-minimally invasive technique for acute uncomplicated appendicitis (AUA). Although laparoscopic appendectomy (LA) is definitive and antibiotic therapy is non-invasive, the comparative efficacy of EDAT versus antibiotics alone remains unclear. PURPOSE To compare the short-term outcomes and recurrence rates of EDAT versus antibiotic therapy in patients with AUA. METHODS This retrospective cohort study included 92 patients with AUA treated at a tertiary center: 41 who underwent EDAT between December 2023 and December 2024 and 51 who received antibiotic therapy between December 2023 and December 2024. Clinical outcomes, including symptom relief, hospital stay, inflammatory markers, treatment success, and recurrence, were compared. Subgroup analyses were performed based on the presence of fecaliths and baseline inflammation severity. RESULTS Baseline characteristics were comparable between groups (all P > 0.05), except for a significantly higher prevalence of fecaliths in the EDAT group (43.9% vs. 21.6%, P = 0.022). EDAT was associated with significantly faster abdominal pain relief [median 12.0 (IQR 12.0–24.0) h vs. 24.0 (12.0–36.0) h, P = 0.008], shorter hospital stay [3.0 (2.0–3.5) days vs. 4.0 (3.0–5.0) days, P < 0.001], and lower postoperative inflammatory markers (WBC: 6.83 ± 1.39 vs. 8.53 ± 1.87 ×10⁹/L, P < 0.001; CRP: 7.89 ± 2.98 vs. 21.16 ± 12.21 mg/L, P < 0.001). Initial treatment success was 100% in both groups (EDAT: 41/41, antibiotics: 51/51; P = 1.000). At a mean follow-up of 7.88 ± 3.52 months (EDAT) and 14.92 ± 2.61 months (antibiotics), recurrence rates were 7.3% (3/41) vs. 27.5% (14/51), respectively (P = 0.014). Subgroup analyses confirmed that EDAT's advantages were consistent across patients with and without fecaliths, as well as across different levels of baseline inflammation severity. CONCLUSION In selected patients with AUA, EDAT offers faster recovery, better inflammatory control, and significantly lower recurrence rates than antibiotic therapy. The presence of fecaliths and elevated baseline CRP predicts antibiotic failure, suggesting that EDAT may be particularly advantageous in these subgroups. Appendicitis Endoscopic direct-vision appendicitis therapy Anti-bacterial agents Recurrence Fecalith Figures Figure 1 INTRODUCTION Acute appendicitis remains one of the most common surgical emergencies worldwide, with a lifetime incidence of approximately 7–8%[ 1 ]. For more than a century, appendectomy has been the standard of care. However, accumulating evidence suggests that surgical resection may be unnecessary for acute uncomplicated appendicitis (AUA)[ 2 ], particularly given the appendix's emerging role as a reservoir for gut microbiota and a lymphoid organ involved in immune regulation[ 3 ]. The management landscape for AUA has evolved substantially over the past two decades. Antibiotic therapy has emerged as a viable non-invasive alternative, with multiple randomized controlled trials demonstrating that a substantial proportion of patients can avoid surgery[ 4 – 6 ]. The landmark APPAC trial and its five-year follow-up reported that while antibiotics were non-inferior to appendectomy in the short term, the recurrence rate exceeded 30%[ 5 , 7 ]. More recently, the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial confirmed that antibiotics are an effective initial treatment, though 29% of patients required appendectomy within one year[ 8 ]. In parallel, endoscopic approaches have been developed to preserve the appendix while providing definitive source control. Endoscopic retrograde appendicitis therapy (ERAT), first described by Liu et al. in 2012[ 9 ], represents a paradigm shift toward organ-preserving treatment. A recent network meta-analysis by Wang et al. highlighted the trade-offs among treatment options: appendectomy offers the lowest recurrence but carries surgical risks, while antibiotic therapy is non-invasive but associated with higher recurrence rates[ 10 ]. Endoscopic direct-vision appendicitis therapy (EDAT), a refinement of ERAT, utilizes a subscope for real-time visualization of the appendiceal lumen, thereby avoiding radiation exposure and enabling more precise intervention[ 11 ]. Our previous study demonstrated that EDAT is superior to laparoscopic appendectomy (LA) in terms of faster recovery and better inflammatory control, with a recurrence rate of 7.3% at a mean follow-up of 7.9 months[ 12 ]. However, the comparative effectiveness of EDAT versus antibiotic therapy remains unexplored. This study aims to address this gap by comparing short-term outcomes and recurrence rates between EDAT and antibiotic treatment in patients with AUA. MATERIALS AND METHODS Study Design and Patient Selection This retrospective cohort study was conducted at Zhejiang Hospital, a tertiary referral center in Hangzhou, China. The EDAT group comprised 41 patients who underwent endoscopic direct-vision therapy between December 2023 and December 2024 according to the same institutional protocol[ 12 ]. The antibiotic group included 51 consecutive patients with AUA who received antibiotic therapy as the initial treatment between December 2023 and December 2024. All patients were diagnosed with AUA based on: (1) abdominal computed tomography (CT) or ultrasound findings showing appendiceal diameter ≥ 6 mm, wall thickening ≥ 3 mm, without evidence of perforation, abscess, or diffuse peritonitis[ 13 ]; and (2) Alvarado score 5–7 (moderate inflammation, excluding severe inflammation with Alvarado score ≥ 8) [ 13 , 14 ]. Inclusion criteria were: (1) age 18–75 years; (2) confirmed AUA meeting the aforementioned diagnostic criteria; (3) no contraindications to either treatment modality. Exclusion criteria were: (1) complicated appendicitis (perforation, abscess, peritonitis); (2) severe organ dysfunction; (3) pregnancy or lactation; (4) other causes of acute abdominal pain; (5) appendiceal diameter > 10 mm or fecalith diameter ≥ 5 mm (predicted to be difficult for endoscopic removal, applied to both groups to maintain comparability). This study was approved by the Ethics Committee of Zhejiang Hospital (Approval No. : ZJHIRB-003K), with a waiver of informed consent due to the retrospective nature. Treatment Protocols EDAT Group: All procedures were performed within 12 hours of admission by three senior endoscopists with expertise in therapeutic endoscopy. A colonoscope with a transparent cap was advanced to the cecum to identify the appendiceal orifice. Intubation of the appendiceal lumen was achieved using a guidewire (0.035'', Changzhou Leao Medical Technology) and, when necessary, a high-frequency incision knife (Boston Scientific). A disposable electronic appendiceal subscope (Hangzhou Lesite Medical Technology) was advanced through the biopsy channel to directly visualize the appendiceal lumen. The lumen was examined for fecaliths, pus, and mucosal inflammation. Irrigation was performed using 100ml of metronidazole sodium chloride injection followed by normal saline until the effluent was clear. Systemic antibiotics were not routinely administered after EDAT. However, patients with preoperative CRP > 80 mg/L (n = 6, 14.6%) received oral cefuroxime axetil (500 mg twice daily) for 3 days post-procedure[ 12 ]. All other EDAT patients received no systemic antibiotics. For large or impacted fecaliths that could not be completely removed, a 5Fr × 5cm plastic stent (Flex Ltd.) was placed to ensure drainage. Detailed procedural steps have been previously described[ 12 , 15 ]. Antibiotic Group: Patients received intravenous antibiotics according to local guidelines. The most common regimen was intravenous ceftriaxone (2g daily) plus metronidazole (500mg three times daily) for 2–3 days, followed by oral antibiotics (amoxicillin-clavulanate or ciprofloxacin plus metronidazole) for a total duration of 5–7 days, consistent with published protocols[ 4 , 8 ]. The choice of antibiotics was at the discretion of the treating physician. Treatment failure was defined as the need for appendectomy during the initial hospital stay due to symptom progression or lack of improvement. Procedural Images Key steps of the EDAT procedure are illustrated in Fig. 1 . After colonoscopic identification of the appendiceal orifice (Fig. 1 A), a guidewire was advanced into the appendiceal lumen, often facilitated by a high-frequency incision knife (Fig. 1 B). A disposable electronic subscope was then inserted over the guidewire to directly visualize the appendiceal lumen, allowing assessment of mucosal inflammation and detection of fecaliths (Fig. 1 C). In cases where complete fecalith removal was not feasible, a plastic stent was placed to ensure drainage patency (Fig. 1 D). All images are representative cases from the EDAT cohort. Data Collection and Outcomes The following data were extracted from electronic medical records: demographics (age, sex), clinical characteristics (Alvarado score, presence of fecaliths on imaging), laboratory parameters (white blood cell [WBC] count, C-reactive protein [CRP] before treatment and on day 2 post-treatment), and treatment outcomes. Primary outcomes were: (1) treatment success (resolution of symptoms without need for surgery during initial hospitalization); (2) recurrence rate during follow-up (defined as reappearance of symptoms with imaging confirmation of acute appendicitis). Secondary outcomes included: (1) time to abdominal pain relief (hours until Visual Analog Scale ≤ 2); (2) length of hospital stay (days); (3) postoperative inflammatory markers (WBC, CRP); (4) complications. Follow-up was conducted via telephone interviews and outpatient clinic records. For the antibiotic group, follow-up was extended to a minimum of 12 months where possible. Definitions Treatment success was defined as complete resolution of symptoms without the need for appendectomy during the index hospitalization. Recurrence was defined as reappearance of symptoms consistent with acute appendicitis, confirmed by imaging (CT or ultrasound), after initial discharge. Time to pain relief was defined as the interval from treatment initiation to the first time the patient reported a Visual Analog Scale score ≤ 2. Statistical Analysis Statistical analysis was performed using SPSS version 23.0 (IBM Corp., Armonk, NY, United States). Continuous variables were tested for normality using the Shapiro-Wilk test. Normally distributed data were expressed as mean ± standard deviation and compared using the independent samples t-test. Non-normally distributed data were expressed as median (interquartile range) and compared using the Mann-Whitney U test. Categorical variables were expressed as frequencies (percentages) and compared using the chi-square test or Fisher's exact test as appropriate. To address potential confounding due to the retrospective design and baseline differences, we performed subgroup analyses stratified by: (1) fecalith presence; and (2) baseline inflammation severity (CRP ≤ 60 mg/L vs. >60 mg/L). Intragroup comparisons of preoperative and postoperative indicators were performed using paired t-test or Wilcoxon signed-rank test. A two-tailed P-value < 0.05 was considered statistically significant. RESULTS Baseline Characteristics A total of 92 patients were included (41 EDAT, 51 antibiotics). Baseline characteristics are summarized in Table 1 . The EDAT group had a numerically higher proportion of male patients (46.3% vs. 62.7%, P = 0.116) and was slightly older (43.41 ± 15.00 vs. 39.37 ± 12.81 years, P = 0.167), although these differences did not reach statistical significance. The Alvarado score was comparable between groups [6.0 (5.0–6.0) vs. 6.0 (5.0–6.0), P = 0.689]. Notably, the prevalence of fecaliths on preoperative imaging was significantly higher in the EDAT group (43.9% vs. 21.6%, P = 0.022). This reflects the different treatment selection pathways: patients with visible fecaliths were more likely to be offered EDAT due to concerns about antibiotic failure. Preoperative WBC was comparable between groups (14.82 ± 2.03 vs. 14.13 ± 3.12, P = 0.204), while preoperative CRP showed a trend toward higher levels in the antibiotic group (60.97 ± 24.32 vs. 70.96 ± 31.93, P = 0.102), though the difference did not reach statistical significance. Table 1 Baseline Characteristics Characteristic EDAT Group (n = 41) Antibiotic Group (n = 51) Test Statistic P-value Age (years), mean ± SD 43.41 ± 15.00 39.37 ± 12.81 t = 1.393 0.167 Sex, male, n (%) 19 (46.3) 32 (62.7) χ²=2.476 0.116 Alvarado score, median (IQR) 6.0 (5.0–6.0) 6.0 (5.0–6.0) U = 957.50 0.456 Fecalith present, n (%) 18 (43.9) 11 (21.6) χ²=5.252 0.022 Preoperative WBC (×10⁹/L), mean ± SD 14.82 ± 2.03 14.13 ± 3.12 t = 1.279 0.204 Preoperative CRP (mg/L), mean ± SD 60.97 ± 24.32 70.96 ± 31.93 t=−1.655 0.102 EDAT: Endoscopic direct-vision appendicitis therapy; SD: standard deviation; IQR: interquartile range; WBC: white blood cell; CRP: C-reactive protein Treatment Outcomes All 41 patients (100%) in the EDAT group underwent successful procedures without intraoperative complications. In the antibiotic group, all 51 patients (100%) achieved initial treatment success without requiring appendectomy during the index hospitalization. The initial treatment success rate was 100% in both groups (P = 1.000). As shown in Table 2 , EDAT was associated with significantly faster symptom resolution compared to antibiotics. The median time to abdominal pain relief was 12.0 (IQR 12.0–24.0) hours in the EDAT group versus 24.0 (IQR 12.0–36.0) hours in the antibiotic group (P = 0.008). Hospital stay was also shorter in the EDAT group [3.0 (2.0-3.5) days vs. 4.0 (3.0–5.0) days, P < 0.001]. Postoperative inflammatory markers were markedly lower in the EDAT group. Day 2 WBC count was 6.83 ± 1.39 ×10⁹/L in the EDAT group versus 8.53 ± 1.87 ×10⁹/L in the antibiotic group (P < 0.001). Day 2 CRP was 7.89 ± 2.98 mg/L versus 21.16 ± 12.21 mg/L, respectively (P < 0.001). Table 2 Clinical Outcomes Outcome EDAT Group (n = 41) Antibiotic Group (n = 51) Test Statistic P-value Time to pain relief (h), median (IQR) 12.0 (12.0–24.0) 24.0 (12.0–36.0) U = 715.50 0.008 Hospital stay (days), median (IQR) 3.0 (2.0-3.5) 4.0 (4.0–5.0) U = 345.00 < 0.001 Day 2 WBC (×10⁹/L), mean ± SD 6.83 ± 1.39 8.53 ± 1.87 t=−4.841 < 0.001 Day 2 CRP (mg/L), mean ± SD 7.89 ± 2.98 21.16 ± 12.21 t=−6.788 < 0.001 IQR: interquartile range; SD: standard deviation; WBC: white blood cell; CRP: C-reactive protein; Serum Inflammatory Markers Table 3 presents the changes in serum inflammatory markers before and after treatment. Both groups showed significant reductions in WBC and CRP after treatment (all P < 0.001). The magnitude of WBC reduction was significantly greater in the EDAT group (7.99 ± 1.63 vs. 5.60 ± 2.03 ×10⁹/L, P < 0.001). Although the absolute reduction in CRP was similar between groups (53.07 ± 21.87 vs. 49.80 ± 22.59 mg/L, P = 0.485), the significantly lower postoperative levels in the EDAT group (7.89 ± 2.98 vs. 21.16 ± 12.21 mg/L, P < 0.001) indicate more complete resolution of inflammation. Table 3 Serum Inflammatory Markers Before and After Treatment Parameter EDAT Group (n = 41) Antibiotic Group (n = 51) Between-group P-value WBC (×10⁹/L), mean ± SD Preoperative 14.82 ± 2.03 14.13 ± 3.12 0.204 Postoperative day 2 6.83 ± 1.39 8.54 ± 1.87 < 0.001 Change (pre - post) 7.99 ± 1.63 5.60 ± 2.03 < 0.001 Within-group P-value < 0.001 < 0.001 - CRP (mg/L), mean ± SD Preoperative 60.97 ± 24.32 70.96 ± 31.93 0.102 Postoperative day 2 7.89 ± 2.98 21.16 ± 12.21 < 0.001 Change (pre - post) 53.07 ± 21.87 49.80 ± 22.59 0.485 Within-group P-value < 0.001 < 0.001 - Data are presented as mean ± standard deviation. Change = preoperative value - postoperative value. Within-group comparisons were performed using paired t-test or Wilcoxon signed-rank test. Recurrence and Long-term Outcomes The mean follow-up duration was significantly longer in the antibiotic group than in the EDAT group (14.92 ± 2.61 vs. 7.88 ± 3.52 months, P < 0.001). During follow-up, 3 patients (7.3%) in the EDAT group experienced recurrent appendicitis, compared to 14 patients (27.5%) in the antibiotic group (P = 0.014). The median time to recurrence was 3 months (range 1–6 months) in the EDAT group and 5 months (range 2–14 months) in the antibiotic group. Among the 51 patients in the antibiotic group, all achieved initial treatment success without requiring appendectomy during the index hospitalization. During follow-up, 14 patients (27.5%) experienced recurrent appendicitis. Among these 14 patients with recurrence, 12 underwent laparoscopic appendectomy (all uneventful), and 2 were successfully treated with a second course of antibiotics. All 3 patients with recurrence in the EDAT group underwent laparoscopic appendectomy without complications. Subgroup Analysis: Impact of Fecaliths Given the significant baseline difference in fecalith prevalence, we performed a stratified analysis based on fecalith presence (Table 4 ). Among patients without fecaliths, both treatments achieved excellent initial success rates (EDAT: 100% [23/23]; antibiotics: 100% [40/40]; P = 1.000). However, EDAT was associated with significantly faster pain relief, shorter hospital stay, and lower postoperative inflammatory markers (all P < 0.05, Table 4 ). The recurrence rate was numerically lower in the EDAT group, though the difference did not reach statistical significance (EDAT: 4.3% [1/23] vs. antibiotics: 17.5% [7/40]; P = 0.218). In contrast, among patients with fecaliths, the differences were striking. Both treatments achieved 100% initial success (EDAT: 18/18; antibiotics: 11/11). However, EDAT was associated with significantly faster pain relief, shorter hospital stay, and markedly lower postoperative inflammatory markers (Table 4 ). The recurrence rate was 11.1% (2/18) in the EDAT group versus 54.5% (6/11) in the antibiotic group (P = 0.021), representing a nearly five-fold reduction. Table 4 Subgroup Analysis by Fecalith Presence Stratification Standard Group Postoperative WBC(10 ^ 9/L) Postoperative CRP (mg/L) Postoperative abdominal pain relief time (hour) Hospital stay (day) Without Fecaliths EDAT (n = 23) 7.22 ± 1.35 8.32 ± 1.74 12.00 (12.00, 24.00) 3.00 (2.00, 4.00) Antibiotics (n = 40) 8.49 ± 1.91 20.71 ± 11.42 24.00 (12.00, 36.00) 4.00 (4.00, 5.00) P 0.006 < 0.001 0.022 < 0.001 With Fecaliths EDAT (n = 18) 6.35 ± 1.31 7.35 ± 4.06 12.00 (10.50,24.00) 3.00 (2.00, 3.25) Antibiotics (n = 11) 8.69 ± 1.81 22.80 ± 15.29 24.00 (12.00, 36.00) 4.00 (4.00, 5.00) P < 0.001 0.007 0.165 0.001 Subgroup Analysis: Impact of Baseline Inflammation Severity To further explore the consistency of treatment effects, we stratified patients by baseline CRP level (≤ 60 mg/L vs. >60 mg/L), as shown in Table 5 . EDAT demonstrated superior outcomes across both strata, with faster symptom relief, shorter hospital stay, and lower postoperative inflammatory markers in all comparisons. In patients with mild inflammation (CRP ≤ 60 mg/L), the recurrence rate was 1/22 (4.5%) in the EDAT group versus 4/21 (19.0%) in the antibiotic group (P = 0.354). In patients with moderate-to-severe inflammation (CRP > 60 mg/L), the difference was more pronounced and statistically significant: 2/19 (10.5%) versus 10/30 (33.3%) (P = 0.042). This suggests that the benefits of EDAT over antibiotics are particularly evident in patients with more severe baseline inflammation. Table 5 Subgroup Analysis by Baseline Inflammation Severity Stratification Standard Group Postoperative WBC(10 ^ 9/L) Postoperative CRP (mg/L) Postoperative abdominal pain relief time (hour) Hospital stay (day) Preoperative CRP≤60mg/L (EDAT n = 22; Antibiotics n = 21) EDAT 6.30 ± 1.23 6.81 ± 1.41 12.00 (10.50, 24.00) 3.00 (2.00, 3.00) Antibiotics 7.26 ± 1.28 11.90 ± 4.51 24.00 (12.00, 42.00) 4.00 (3.50, 5.00) P 0.017 < 0.001 0.015 60mg/L (EDAT n = 19; Antibiotics n = 30) EDAT 7.45 ± 1.32 9.15 ± 3.79 24.00 (12.00,24.00) 3.00 (3.00, 4.00) Antibiotics 9.43 ± 1.71 27.64 ± 11.73 24.00 (12.00, 36.00) 4.00 (4.00, 5.00) P < 0.001 < 0.001 0.378 0.002 DISCUSSION To the best of our knowledge, this study provides the first direct comparison between EDAT and antibiotic therapy for AUA. Our findings demonstrate that EDAT offers significant advantages over antibiotics in terms of faster symptom resolution, shorter hospital stay, better control of systemic inflammation, and, most importantly, substantially lower recurrence rates. These benefits were consistent across subgroup analyses stratified by fecalith presence and baseline inflammation severity, suggesting that EDAT's advantages are robust across a spectrum of disease presentations. The management of AUA has evolved from a purely surgical paradigm to a more nuanced approach that incorporates both conservative and interventional options[ 16 ]. Antibiotic therapy has gained traction following multiple RCTs demonstrating its feasibility[ 4 – 6 ]. The APPAC trial reported 1-year treatment success of 72.7% with antibiotics[ 5 ], while the CODA trial found that 29% of patients randomized to antibiotics underwent appendectomy within one year[ 8 ]. A recent meta-analysis by Salminen et al. confirmed that while antibiotics are effective in the short term, long-term recurrence remains a significant concern, exceeding 30% at five years[ 7 , 17 ]. EDAT occupies a unique middle ground between these two extremes. Unlike antibiotics, which rely on the host immune response and spontaneous resolution of obstruction, EDAT provides mechanical relief of luminal obstruction through direct visualization, irrigation, and fecalith removal when present[ 9 ]. This mechanistic difference likely explains the superior outcomes observed in our study, particularly the dramatic reduction in recurrence compared to antibiotics (7.3% vs. 27.5%). Our recurrence rate for EDAT aligns closely with the 7–10% reported for ERAT-like techniques in a recent network meta-analysis[ 10 ], while the antibiotic recurrence rate is consistent with the 30% figure reported in long-term follow-up studies[ 7 , 17 ]. Our subgroup analysis identified fecalith presence as the most important factor influencing outcomes, particularly in the antibiotic group. Among patients with fecaliths treated with antibiotics, the recurrence rate was 54.5% (6/11), compared to only 17.5% (7/40) in those without fecaliths. This finding is consistent with a growing body of evidence suggesting that fecaliths are a marker of more severe disease and a predictor of antibiotic failure[ 18 – 20 ]. A post-hoc analysis of the APPAC trial by Haijanen et al. demonstrated that the presence of an appendicolith was associated with a significantly higher risk of treatment failure (hazard ratio [HR] 3.47)[ 18 ]. Similarly, the CODA trial reported that patients with appendicoliths had a higher rate of appendectomy within 90 days (25% vs. 13%)[ 8 ]. Our findings extend these observations by showing that EDAT effectively mitigates this risk: patients with fecaliths treated with EDAT had an 11.1% (2/18) recurrence rate, which was not significantly different from the 4.3% (1/23) rate in patients without fecaliths treated with EDAT (P = 0.218). This has important clinical implications. For patients presenting with AUA and visible fecaliths on imaging, antibiotic therapy alone may be suboptimal, and early intervention with EDAT should be strongly considered. Conversely, in patients without fecaliths and mild-to-moderate inflammation, antibiotic therapy remains a reasonable first-line option, though patients should be counseled about the approximately 15–20% recurrence risk. The superior inflammatory control observed with EDAT warrants discussion. Post-treatment CRP was nearly three times lower in the EDAT group compared to the antibiotic group (7.89 vs. 21.16 mg/L), and the magnitude of WBC reduction was significantly greater. This difference likely reflects the fundamental distinction between source control (EDAT) and systemic therapy (antibiotics). By directly removing the obstructing nidus and purulent material, EDAT rapidly reduces the bacterial load and intraluminal pressure, leading to faster resolution of the inflammatory cascade[ 21 ]. Antibiotics, while effective against systemic bacterial dissemination, do not address the mechanical obstruction and may take longer to achieve clinical response. The faster symptom relief (12 vs. 24 hours) and shorter hospital stay (3 vs. 4 days) associated with EDAT have practical implications for healthcare resource utilization and patient satisfaction. A cost-effectiveness analysis would be valuable to quantify these benefits, though it was beyond the scope of this retrospective study. We have previously shown that EDAT is superior to LA in terms of recovery speed and inflammatory control, with comparable safety[ 12 ]. The current study extends this evidence by showing that EDAT also outperforms antibiotics, particularly in patients with fecaliths or more severe baseline inflammation. Taken together, these findings position EDAT as a versatile alternative that may be preferable to both surgical and conservative approaches in selected patients. The 14.6% stent placement rate in our EDAT cohort is comparable to other published series[ 15 , 22 ] and reflects the technical reality that complete fecalith removal is not always achievable. Stent placement ensures drainage patency and may reduce the risk of early recurrence, though this requires prospective validation. Our findings support a stratified approach to treatment selection for AUA. For patients without fecaliths and with mild inflammation (CRP ≤ 60 mg/L), antibiotic therapy remains a reasonable first-line option, with an expected recurrence rate of approximately 15–20%. However, patients should be counseled about this risk and offered EDAT if they prioritize faster recovery and lower recurrence. For patients with fecaliths or more severe inflammation (CRP > 60 mg/L), antibiotic therapy is associated with a high failure rate (up to 54.5%), and EDAT should be strongly recommended when available. It is worth noting that systemic antibiotics were used sparingly in the EDAT group (only 14.6% of patients), whereas all antibiotic group patients received full-course systemic therapy. Despite this, EDAT achieved significantly lower recurrence rates, underscoring the primacy of mechanical source control over systemic antimicrobial therapy alone. This study has several limitations that should be acknowledged. First, the retrospective design introduces potential selection bias. The higher prevalence of fecaliths in the EDAT group suggests that clinicians preferentially offered EDAT to patients with more complex disease, which would be expected to bias results against EDAT. Despite this, EDAT demonstrated superior outcomes, strengthening our conclusions. However, unmeasured confounders cannot be excluded. Second, the sample size is modest, limiting our ability to detect small differences in some subgroup analyses. The imbalance in fecalith prevalence between groups, while informative, complicates direct comparisons and necessitated stratified analysis. Third, the follow-up duration differed between groups, with the antibiotic group having longer follow-up (14.9 vs. 7.9 months). This difference would tend to favor antibiotics in terms of recurrence detection, yet EDAT still demonstrated significantly lower recurrence rates, reinforcing the robustness of this finding. Fourth, the antibiotic regimens were not standardized, reflecting real-world practice but introducing heterogeneity. However, the consistency of our findings with published RCTs suggests that this heterogeneity did not materially affect conclusions. Finally, as a single-center study from a tertiary referral center with expertise in EDAT, our findings may not be generalizable to centers without such expertise. The learning curve for EDAT is not trivial, and outcomes may vary with operator experience[ 23 ]. Despite these limitations, our findings have several important clinical implications. For patients with AUA, particularly those with visible fecaliths or elevated baseline CRP, EDAT offers a compelling alternative to both surgery and antibiotics. It provides the benefits of organ preservation with faster recovery than surgery and lower recurrence than antibiotics. For clinical practice, our results support a stratified approach to treatment selection. Patients without fecaliths and mild inflammation may reasonably choose between antibiotics and EDAT, with antibiotics offering a non-invasive option and EDAT providing faster recovery and lower recurrence. Patients with fecaliths or more severe inflammation should be counseled about the higher risk of antibiotic failure and recurrence, and EDAT should be strongly recommended when available. Future research should focus on: (1) large-scale, multicenter randomized controlled trials comparing EDAT with both antibiotics and surgery, with long-term follow-up to 3–5 years; (2) development of validated prediction models to identify patients most likely to benefit from each treatment approach; (3) cost-effectiveness analyses to inform healthcare policy; (4) standardization of EDAT technique and training to ensure reproducible outcomes across centers[ 24 ]. CONCLUSION This study provides the first evidence comparing EDAT with antibiotic therapy for acute uncomplicated appendicitis. EDAT offers faster symptom resolution, shorter hospital stay, better inflammatory control, and significantly lower recurrence rates compared to antibiotics alone. The presence of fecaliths and elevated baseline CRP identify subgroups of patients at particularly high risk of antibiotic failure who may derive the greatest benefit from EDAT. These findings support the integration of EDAT into the therapeutic armamentarium for AUA as an organ-preserving alternative that occupies a unique and valuable niche between conservative management and surgical resection. Prospective randomized trials are needed to confirm these findings and establish the optimal role of EDAT in clinical practice. Declarations Author Contribution Chen LP: study concept and design, data collection, manuscript drafting, statistical analysis; Zhou F: data collection, manuscript revision; Cheng QR: data collection, follow-up; Feng YL: endoscopic procedures, critical revision. All authors approved the final version. Disclosure statement Drs. Li-peng Chen, Feng Zhou, Qi-run Cheng, Yu-liang Feng have no conflicts of interest or financial ties to disclose. Human Ethics and Consent to Participate declarations Ethical committee approval was received from the Ethics Committee of Zhejiang Hospital (Approval no: ZJHIRB-003K). Waiver of informed consent was obtained due to the retrospective nature of the study, as approved by the Ethics Committee of Zhejiang Hospital. Funding declarations The authors declared that this study has received no financial support. Data Availability Statement The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy and ethical restrictions, as they contain information that could compromise the privacy of research participants. References Stewart B, Khanduri P, McCord C et al (2014) Global disease burden of conditions requiring emergency surgery. 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Ann Surg 278(2):e272–e280. 10.1097/SLA.0000000000005905 Sippola S, Haijanen J, Viinikainen L et al (2020) Quality of life and patient satisfaction at 7-year follow-up of antibiotic therapy vs appendectomy for uncomplicated acute appendicitis: A secondary analysis of the APPAC randomized clinical trial. JAMA Surg 155(4):283–289. 10.1001/jamasurg.2019.6028 Flum DR, Davidson GH, Monsell SE et al (2020) A randomized trial comparing antibiotics with appendectomy for appendicitis. N Engl J Med 383(20):1907–1919. 10.1056/NEJMoa2014320 Liu BR, Song JT, Han FY, Li H, Yin JB (2012) Endoscopic retrograde appendicitis therapy: a pilot minimally invasive technique (with videos). Gastrointest Endosc 76(4):862–866. 10.1016/j.gie.2012.05.029 Wang J, Yin J, Wang C, Zhu Y (2025) The safety and efficacy of appendectomy, endoscopic retrograde appendicitis therapy, and antibiotic treatment for acute uncomplicated appendicitis: A systematic review and network meta-analysis of randomized controlled trials. BMC Surg 25(1):435. 10.1186/s12893-025-03176-1 Lin D, Su M et al (2024) Direct visualization endoscopic retrograde appendicitis therapy for treatment of acute uncomplicated appendicitis. Surg Endosc 38(10):6156–6160. 10.1007/s00464-024-11112-2 Chen L, Zhou F, Yu X, Feng Y (2026) Endoscopic direct-vision therapy for acute uncomplicated appendicitis: A retrospective study. Turk J Gastroenterol. ; [In press]. Damburac N, Sevin B, Güner M, Karahan Ö (2020) Comparison of Raja Isteri Pengiran Anak Saleha Appendicitis and modified Alvarado scoring systems in the diagnosis of acute appendicitis. ANZ J Surg 90(4):521–524. 10.1111/ans.15607 Pata F, Nardo B, Ielpo B et al (2023) Endoscopic retrograde appendicitis therapy versus appendectomy or antibiotics in the modern approach to uncomplicated acute appendicitis: A systematic review and meta-analysis. Surgery 174(6):1292–1301. 10.1016/j.surg.2023.08.029 Ren LH, Ding Y, Li Y et al (2025) Endoscopic direct-vision appendicitis therapy for the treatment of chronic appendicitis with multiple appendicoliths. Endoscopy 57(S01):E617–E618. 10.1055/a-2602-3154 Talan DA, Saltzman DJ, Mower WR et al (2017) Antibiotics-first versus surgery for appendicitis: A US pilot randomized controlled trial allowing outpatient antibiotic management. Ann Emerg Med 70(1):1–11e9. 10.1016/j.annemergmed.2016.08.446 Salminen P, Sippola S, Haijanen J et al (2022) Antibiotics versus placebo in adults with CT-confirmed uncomplicated acute appendicitis (APPAC III): randomized double-blind superiority trial. Br J Surg 109(6):503–509. 10.1093/bjs/znac086 Haijanen J, Sippola S, Grönroos J et al (2021) Appendicolith appendicitis is clinically complicated acute appendicitis: Is it histologically different from uncomplicated acute appendicitis? Int J Colorectal Dis 36(7):1393–1400. 10.1007/s00384-021-03909-5 Vons C, Barry C, Maitre S et al (2011) Amoxicillin plus clavulanic acid versus appendicectomy for treatment of acute uncomplicated appendicitis: an open-label, non-inferiority, randomised controlled trial. Lancet 377(9777):1573–1579. 10.1016/S0140-6736(11)60410-8 Mahajan P, Basu T, Pai CW et al (2020) Factors associated with potentially missed diagnosis of appendicitis in the emergency department. JAMA Netw Open 3(3):e200612. 10.1001/jamanetworkopen.2020.0612 Liu BR, Ma X, Feng J et al (2015) Endoscopic retrograde appendicitis therapy (ERAT): a multicenter retrospective study in China. Surg Endosc 29(4):905–909. 10.1007/s00464-014-3750-4 Yang B, Kong L, Ullah S et al (2022) Endoscopic retrograde appendicitis therapy versus laparoscopic appendectomy for uncomplicated acute appendicitis. Endoscopy 54(8):747–754. 10.1055/a-1737-6381 Li Y, Mi C, Li W, She J (2022) The learning curve for endoscopic retrograde appendicitis therapy: a single-center experience of 146 cases. Surg Endosc 36(10):7295–7302. 10.1007/s00464-022-09130-7 Brucchi F, Fugazzola P, Bracchetti G et al (2024) Non-operative management versus appendectomy for acute uncomplicated appendicitis: a systematic review and meta-analysis. World J Emerg Surg 19(1):15. 10.1186/s13017-024-00545-2 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 29 Apr, 2026 Read the published version in International Journal of Colorectal Disease → Version 1 posted Editorial decision: Revision requested 26 Mar, 2026 Reviews received at journal 26 Mar, 2026 Reviews received at journal 22 Mar, 2026 Reviewers agreed at journal 18 Mar, 2026 Reviewers agreed at journal 17 Mar, 2026 Reviewers agreed at journal 16 Mar, 2026 Reviewers agreed at journal 16 Mar, 2026 Reviews received at journal 09 Mar, 2026 Reviewers agreed at journal 08 Mar, 2026 Reviewers invited by journal 08 Mar, 2026 Editor assigned by journal 06 Mar, 2026 Submission checks completed at journal 06 Mar, 2026 First submitted to journal 05 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9039444","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":602938251,"identity":"81ecfe6b-0dab-4e16-ae01-2b37e67247bc","order_by":0,"name":"Lipeng Chen","email":"","orcid":"","institution":"Zhejiang Hospital","correspondingAuthor":false,"prefix":"","firstName":"Lipeng","middleName":"","lastName":"Chen","suffix":""},{"id":602938252,"identity":"a4b4c131-43b3-46e9-9ce5-f1204e9eba98","order_by":1,"name":"Feng Zhou","email":"","orcid":"","institution":"Zhejiang Hospital","correspondingAuthor":false,"prefix":"","firstName":"Feng","middleName":"","lastName":"Zhou","suffix":""},{"id":602938253,"identity":"c89bcd85-e686-4b0e-bd42-662295825793","order_by":2,"name":"Qirun Cheng","email":"","orcid":"","institution":"Zhejiang Hospital","correspondingAuthor":false,"prefix":"","firstName":"Qirun","middleName":"","lastName":"Cheng","suffix":""},{"id":602938254,"identity":"84e6d268-85f7-4754-b4d6-5760eb6afa9d","order_by":3,"name":"Yuliang Feng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAr0lEQVRIiWNgGAWjYBAC+wPMjQcSGBjkGJiJ1WLAwNgA0mJMohYgndhAtMMMJBIbDjzcYZM+v5334AeGGptoglrsQVoSz6TlbjjMlyzBcCwtl6B1YFsS2w7nbmDmMZBgbDhMtJb/6fLNPMY/SNECDLTDPGZE2sLzEKQl2XADUItFAlF+YU8++PBnm528fP8Z4xsfamwIa2EQSEDiJOBQhAr4DxClbBSMglEwCkYyAAAppEEMwioJ5AAAAABJRU5ErkJggg==","orcid":"","institution":"Zhejiang Hospital","correspondingAuthor":true,"prefix":"","firstName":"Yuliang","middleName":"","lastName":"Feng","suffix":""}],"badges":[],"createdAt":"2026-03-05 11:23:44","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9039444/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9039444/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00384-026-05136-4","type":"published","date":"2026-04-29T15:57:26+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":104548478,"identity":"1c22a4d4-5396-4766-950a-442143066ce6","added_by":"auto","created_at":"2026-03-13 07:42:36","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":201258,"visible":true,"origin":"","legend":"\u003cp\u003eKey procedural steps of endoscopic direct-vision appendicitis therapy (EDAT)\u003c/p\u003e\n\u003cp\u003e(A) Appendiceal orifice identified during colonoscopy. (B) Guidewire insertion into the appendiceal lumen using a high-frequency incision knife. (C) Subscope visualization showing mucosal inflammation and an appendicolith. (D) Plastic stent placed to ensure drainage patency.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9039444/v1/40f3e03ef8cee4c4e03245b9.png"},{"id":108438810,"identity":"8a1b61d9-f693-4c6f-8ff6-be394b82fe13","added_by":"auto","created_at":"2026-05-04 16:10:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":502131,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9039444/v1/3ad69ce8-3b75-4873-b066-db6d584c3bbd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Endoscopic Direct-vision Therapy vs. Antibiotics for Acute Uncomplicated Appendicitis: A Retrospective Cohort Study","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eAcute appendicitis remains one of the most common surgical emergencies worldwide, with a lifetime incidence of approximately 7\u0026ndash;8%[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. For more than a century, appendectomy has been the standard of care. However, accumulating evidence suggests that surgical resection may be unnecessary for acute uncomplicated appendicitis (AUA)[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], particularly given the appendix's emerging role as a reservoir for gut microbiota and a lymphoid organ involved in immune regulation[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe management landscape for AUA has evolved substantially over the past two decades. Antibiotic therapy has emerged as a viable non-invasive alternative, with multiple randomized controlled trials demonstrating that a substantial proportion of patients can avoid surgery[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The landmark APPAC trial and its five-year follow-up reported that while antibiotics were non-inferior to appendectomy in the short term, the recurrence rate exceeded 30%[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. More recently, the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial confirmed that antibiotics are an effective initial treatment, though 29% of patients required appendectomy within one year[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn parallel, endoscopic approaches have been developed to preserve the appendix while providing definitive source control. Endoscopic retrograde appendicitis therapy (ERAT), first described by Liu et al. in 2012[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], represents a paradigm shift toward organ-preserving treatment. A recent network meta-analysis by Wang et al. highlighted the trade-offs among treatment options: appendectomy offers the lowest recurrence but carries surgical risks, while antibiotic therapy is non-invasive but associated with higher recurrence rates[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEndoscopic direct-vision appendicitis therapy (EDAT), a refinement of ERAT, utilizes a subscope for real-time visualization of the appendiceal lumen, thereby avoiding radiation exposure and enabling more precise intervention[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Our previous study demonstrated that EDAT is superior to laparoscopic appendectomy (LA) in terms of faster recovery and better inflammatory control, with a recurrence rate of 7.3% at a mean follow-up of 7.9 months[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However, the comparative effectiveness of EDAT versus antibiotic therapy remains unexplored. This study aims to address this gap by comparing short-term outcomes and recurrence rates between EDAT and antibiotic treatment in patients with AUA.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Patient Selection\u003c/h2\u003e \u003cp\u003eThis retrospective cohort study was conducted at Zhejiang Hospital, a tertiary referral center in Hangzhou, China. The EDAT group comprised 41 patients who underwent endoscopic direct-vision therapy between December 2023 and December 2024 according to the same institutional protocol[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The antibiotic group included 51 consecutive patients with AUA who received antibiotic therapy as the initial treatment between December 2023 and December 2024.\u003c/p\u003e \u003cp\u003eAll patients were diagnosed with AUA based on: (1) abdominal computed tomography (CT) or ultrasound findings showing appendiceal diameter\u0026thinsp;\u0026ge;\u0026thinsp;6 mm, wall thickening\u0026thinsp;\u0026ge;\u0026thinsp;3 mm, without evidence of perforation, abscess, or diffuse peritonitis[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]; and (2) Alvarado score 5\u0026ndash;7 (moderate inflammation, excluding severe inflammation with Alvarado score\u0026thinsp;\u0026ge;\u0026thinsp;8) [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eInclusion criteria were: (1) age 18\u0026ndash;75 years; (2) confirmed AUA meeting the aforementioned diagnostic criteria; (3) no contraindications to either treatment modality. Exclusion criteria were: (1) complicated appendicitis (perforation, abscess, peritonitis); (2) severe organ dysfunction; (3) pregnancy or lactation; (4) other causes of acute abdominal pain; (5) appendiceal diameter\u0026thinsp;\u0026gt;\u0026thinsp;10 mm or fecalith diameter\u0026thinsp;\u0026ge;\u0026thinsp;5 mm (predicted to be difficult for endoscopic removal, applied to both groups to maintain comparability).\u003c/p\u003e \u003cp\u003eThis study was approved by the Ethics Committee of Zhejiang Hospital (Approval No. : ZJHIRB-003K), with a waiver of informed consent due to the retrospective nature.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eTreatment Protocols\u003c/h3\u003e\n\u003cp\u003eEDAT Group: All procedures were performed within 12 hours of admission by three senior endoscopists with expertise in therapeutic endoscopy. A colonoscope with a transparent cap was advanced to the cecum to identify the appendiceal orifice. Intubation of the appendiceal lumen was achieved using a guidewire (0.035'', Changzhou Leao Medical Technology) and, when necessary, a high-frequency incision knife (Boston Scientific). A disposable electronic appendiceal subscope (Hangzhou Lesite Medical Technology) was advanced through the biopsy channel to directly visualize the appendiceal lumen. The lumen was examined for fecaliths, pus, and mucosal inflammation. Irrigation was performed using 100ml of metronidazole sodium chloride injection followed by normal saline until the effluent was clear. Systemic antibiotics were not routinely administered after EDAT. However, patients with preoperative CRP\u0026thinsp;\u0026gt;\u0026thinsp;80 mg/L (n\u0026thinsp;=\u0026thinsp;6, 14.6%) received oral cefuroxime axetil (500 mg twice daily) for 3 days post-procedure[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. All other EDAT patients received no systemic antibiotics. For large or impacted fecaliths that could not be completely removed, a 5Fr \u0026times; 5cm plastic stent (Flex Ltd.) was placed to ensure drainage. Detailed procedural steps have been previously described[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e Antibiotic Group: Patients received intravenous antibiotics according to local guidelines. The most common regimen was intravenous ceftriaxone (2g daily) plus metronidazole (500mg three times daily) for 2\u0026ndash;3 days, followed by oral antibiotics (amoxicillin-clavulanate or ciprofloxacin plus metronidazole) for a total duration of 5\u0026ndash;7 days, consistent with published protocols[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The choice of antibiotics was at the discretion of the treating physician. Treatment failure was defined as the need for appendectomy during the initial hospital stay due to symptom progression or lack of improvement.\u003c/p\u003e\n\u003ch3\u003eProcedural Images\u003c/h3\u003e\n\u003cp\u003eKey steps of the EDAT procedure are illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. After colonoscopic identification of the appendiceal orifice (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA), a guidewire was advanced into the appendiceal lumen, often facilitated by a high-frequency incision knife (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). A disposable electronic subscope was then inserted over the guidewire to directly visualize the appendiceal lumen, allowing assessment of mucosal inflammation and detection of fecaliths (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). In cases where complete fecalith removal was not feasible, a plastic stent was placed to ensure drainage patency (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD). All images are representative cases from the EDAT cohort.\u003c/p\u003e \n\u003ch3\u003eData Collection and Outcomes\u003c/h3\u003e\n\u003cp\u003eThe following data were extracted from electronic medical records: demographics (age, sex), clinical characteristics (Alvarado score, presence of fecaliths on imaging), laboratory parameters (white blood cell [WBC] count, C-reactive protein [CRP] before treatment and on day 2 post-treatment), and treatment outcomes.\u003c/p\u003e \u003cp\u003ePrimary outcomes were: (1) treatment success (resolution of symptoms without need for surgery during initial hospitalization); (2) recurrence rate during follow-up (defined as reappearance of symptoms with imaging confirmation of acute appendicitis).\u003c/p\u003e \u003cp\u003eSecondary outcomes included: (1) time to abdominal pain relief (hours until Visual Analog Scale\u0026thinsp;\u0026le;\u0026thinsp;2); (2) length of hospital stay (days); (3) postoperative inflammatory markers (WBC, CRP); (4) complications.\u003c/p\u003e \u003cp\u003eFollow-up was conducted via telephone interviews and outpatient clinic records. For the antibiotic group, follow-up was extended to a minimum of 12 months where possible.\u003c/p\u003e\n\u003ch3\u003eDefinitions\u003c/h3\u003e\n\u003cp\u003eTreatment success was defined as complete resolution of symptoms without the need for appendectomy during the index hospitalization. Recurrence was defined as reappearance of symptoms consistent with acute appendicitis, confirmed by imaging (CT or ultrasound), after initial discharge. Time to pain relief was defined as the interval from treatment initiation to the first time the patient reported a Visual Analog Scale score\u0026thinsp;\u0026le;\u0026thinsp;2.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eStatistical analysis was performed using SPSS version 23.0 (IBM Corp., Armonk, NY, United States). Continuous variables were tested for normality using the Shapiro-Wilk test. Normally distributed data were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation and compared using the independent samples t-test. Non-normally distributed data were expressed as median (interquartile range) and compared using the Mann-Whitney U test. Categorical variables were expressed as frequencies (percentages) and compared using the chi-square test or Fisher's exact test as appropriate.\u003c/p\u003e \u003cp\u003eTo address potential confounding due to the retrospective design and baseline differences, we performed subgroup analyses stratified by: (1) fecalith presence; and (2) baseline inflammation severity (CRP\u0026thinsp;\u0026le;\u0026thinsp;60 mg/L vs. \u0026gt;60 mg/L). Intragroup comparisons of preoperative and postoperative indicators were performed using paired t-test or Wilcoxon signed-rank test. A two-tailed P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eBaseline Characteristics\u003c/h2\u003e \u003cp\u003eA total of 92 patients were included (41 EDAT, 51 antibiotics). Baseline characteristics are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The EDAT group had a numerically higher proportion of male patients (46.3% vs. 62.7%, P\u0026thinsp;=\u0026thinsp;0.116) and was slightly older (43.41\u0026thinsp;\u0026plusmn;\u0026thinsp;15.00 vs. 39.37\u0026thinsp;\u0026plusmn;\u0026thinsp;12.81 years, P\u0026thinsp;=\u0026thinsp;0.167), although these differences did not reach statistical significance. The Alvarado score was comparable between groups [6.0 (5.0\u0026ndash;6.0) vs. 6.0 (5.0\u0026ndash;6.0), P\u0026thinsp;=\u0026thinsp;0.689].\u003c/p\u003e \u003cp\u003eNotably, the prevalence of fecaliths on preoperative imaging was significantly higher in the EDAT group (43.9% vs. 21.6%, P\u0026thinsp;=\u0026thinsp;0.022). This reflects the different treatment selection pathways: patients with visible fecaliths were more likely to be offered EDAT due to concerns about antibiotic failure. Preoperative WBC was comparable between groups (14.82\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03 vs. 14.13\u0026thinsp;\u0026plusmn;\u0026thinsp;3.12, P\u0026thinsp;=\u0026thinsp;0.204), while preoperative CRP showed a trend toward higher levels in the antibiotic group (60.97\u0026thinsp;\u0026plusmn;\u0026thinsp;24.32 vs. 70.96\u0026thinsp;\u0026plusmn;\u0026thinsp;31.93, P\u0026thinsp;=\u0026thinsp;0.102), though the difference did not reach statistical significance.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline Characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT Group (n\u0026thinsp;=\u0026thinsp;41)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAntibiotic Group (n\u0026thinsp;=\u0026thinsp;51)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTest Statistic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43.41\u0026thinsp;\u0026plusmn;\u0026thinsp;15.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.37\u0026thinsp;\u0026plusmn;\u0026thinsp;12.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.167\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex, male, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19 (46.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32 (62.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eχ\u0026sup2;=2.476\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.116\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlvarado score, median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.0 (5.0\u0026ndash;6.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.0 (5.0\u0026ndash;6.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eU\u0026thinsp;=\u0026thinsp;957.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.456\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFecalith present, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18 (43.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (21.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eχ\u0026sup2;=5.252\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.022\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative WBC (\u0026times;10⁹/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.82\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.13\u0026thinsp;\u0026plusmn;\u0026thinsp;3.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003et\u0026thinsp;=\u0026thinsp;1.279\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.204\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative CRP (mg/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60.97\u0026thinsp;\u0026plusmn;\u0026thinsp;24.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70.96\u0026thinsp;\u0026plusmn;\u0026thinsp;31.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003et=\u0026minus;1.655\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.102\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eEDAT: Endoscopic direct-vision appendicitis therapy; SD: standard deviation; IQR: interquartile range; WBC: white blood cell; CRP: C-reactive protein\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eTreatment Outcomes\u003c/h2\u003e \u003cp\u003eAll 41 patients (100%) in the EDAT group underwent successful procedures without intraoperative complications. In the antibiotic group, all 51 patients (100%) achieved initial treatment success without requiring appendectomy during the index hospitalization. The initial treatment success rate was 100% in both groups (P\u0026thinsp;=\u0026thinsp;1.000).\u003c/p\u003e \u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, EDAT was associated with significantly faster symptom resolution compared to antibiotics. The median time to abdominal pain relief was 12.0 (IQR 12.0\u0026ndash;24.0) hours in the EDAT group versus 24.0 (IQR 12.0\u0026ndash;36.0) hours in the antibiotic group (P\u0026thinsp;=\u0026thinsp;0.008). Hospital stay was also shorter in the EDAT group [3.0 (2.0-3.5) days vs. 4.0 (3.0\u0026ndash;5.0) days, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001].\u003c/p\u003e \u003cp\u003ePostoperative inflammatory markers were markedly lower in the EDAT group. Day 2 WBC count was 6.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39 \u0026times;10⁹/L in the EDAT group versus 8.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87 \u0026times;10⁹/L in the antibiotic group (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Day 2 CRP was 7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.98 mg/L versus 21.16\u0026thinsp;\u0026plusmn;\u0026thinsp;12.21 mg/L, respectively (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical Outcomes\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT Group (n\u0026thinsp;=\u0026thinsp;41)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAntibiotic Group (n\u0026thinsp;=\u0026thinsp;51)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTest Statistic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime to pain relief (h), median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12.0 (12.0\u0026ndash;24.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24.0 (12.0\u0026ndash;36.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eU\u0026thinsp;=\u0026thinsp;715.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHospital stay (days), median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.0 (2.0-3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.0 (4.0\u0026ndash;5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eU\u0026thinsp;=\u0026thinsp;345.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDay 2 WBC (\u0026times;10⁹/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003et=\u0026minus;4.841\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDay 2 CRP (mg/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21.16\u0026thinsp;\u0026plusmn;\u0026thinsp;12.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003et=\u0026minus;6.788\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eIQR: interquartile range; SD: standard deviation; WBC: white blood cell; CRP: C-reactive protein;\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eSerum Inflammatory Markers\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e presents the changes in serum inflammatory markers before and after treatment. Both groups showed significant reductions in WBC and CRP after treatment (all P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The magnitude of WBC reduction was significantly greater in the EDAT group (7.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.63 vs. 5.60\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03 \u0026times;10⁹/L, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Although the absolute reduction in CRP was similar between groups (53.07\u0026thinsp;\u0026plusmn;\u0026thinsp;21.87 vs. 49.80\u0026thinsp;\u0026plusmn;\u0026thinsp;22.59 mg/L, P\u0026thinsp;=\u0026thinsp;0.485), the significantly lower postoperative levels in the EDAT group (7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.98 vs. 21.16\u0026thinsp;\u0026plusmn;\u0026thinsp;12.21 mg/L, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) indicate more complete resolution of inflammation.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSerum Inflammatory Markers Before and After Treatment\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT Group (n\u0026thinsp;=\u0026thinsp;41)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAntibiotic Group (n\u0026thinsp;=\u0026thinsp;51)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBetween-group P-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e \u003cp\u003eWBC (\u0026times;10⁹/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.82\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.13\u0026thinsp;\u0026plusmn;\u0026thinsp;3.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.204\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative day 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.54\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChange (pre - post)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.99\u0026thinsp;\u0026plusmn;\u0026thinsp;1.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.60\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWithin-group P-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e \u003cp\u003eCRP (mg/L), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e60.97\u0026thinsp;\u0026plusmn;\u0026thinsp;24.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70.96\u0026thinsp;\u0026plusmn;\u0026thinsp;31.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.102\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative day 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.16\u0026thinsp;\u0026plusmn;\u0026thinsp;12.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChange (pre - post)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53.07\u0026thinsp;\u0026plusmn;\u0026thinsp;21.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49.80\u0026thinsp;\u0026plusmn;\u0026thinsp;22.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.485\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWithin-group P-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eData are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. Change\u0026thinsp;=\u0026thinsp;preoperative value - postoperative value. Within-group comparisons were performed using paired t-test or Wilcoxon signed-rank test.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eRecurrence and Long-term Outcomes\u003c/h2\u003e \u003cp\u003eThe mean follow-up duration was significantly longer in the antibiotic group than in the EDAT group (14.92\u0026thinsp;\u0026plusmn;\u0026thinsp;2.61 vs. 7.88\u0026thinsp;\u0026plusmn;\u0026thinsp;3.52 months, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). During follow-up, 3 patients (7.3%) in the EDAT group experienced recurrent appendicitis, compared to 14 patients (27.5%) in the antibiotic group (P\u0026thinsp;=\u0026thinsp;0.014). The median time to recurrence was 3 months (range 1\u0026ndash;6 months) in the EDAT group and 5 months (range 2\u0026ndash;14 months) in the antibiotic group.\u003c/p\u003e \u003cp\u003eAmong the 51 patients in the antibiotic group, all achieved initial treatment success without requiring appendectomy during the index hospitalization. During follow-up, 14 patients (27.5%) experienced recurrent appendicitis. Among these 14 patients with recurrence, 12 underwent laparoscopic appendectomy (all uneventful), and 2 were successfully treated with a second course of antibiotics. All 3 patients with recurrence in the EDAT group underwent laparoscopic appendectomy without complications.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eSubgroup Analysis: Impact of Fecaliths\u003c/h2\u003e \u003cp\u003eGiven the significant baseline difference in fecalith prevalence, we performed a stratified analysis based on fecalith presence (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Among patients without fecaliths, both treatments achieved excellent initial success rates (EDAT: 100% [23/23]; antibiotics: 100% [40/40]; P\u0026thinsp;=\u0026thinsp;1.000). However, EDAT was associated with significantly faster pain relief, shorter hospital stay, and lower postoperative inflammatory markers (all P\u0026thinsp;\u0026lt;\u0026thinsp;0.05, Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The recurrence rate was numerically lower in the EDAT group, though the difference did not reach statistical significance (EDAT: 4.3% [1/23] vs. antibiotics: 17.5% [7/40]; P\u0026thinsp;=\u0026thinsp;0.218).\u003c/p\u003e \u003cp\u003eIn contrast, among patients with fecaliths, the differences were striking. Both treatments achieved 100% initial success (EDAT: 18/18; antibiotics: 11/11). However, EDAT was associated with significantly faster pain relief, shorter hospital stay, and markedly lower postoperative inflammatory markers (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The recurrence rate was 11.1% (2/18) in the EDAT group versus 54.5% (6/11) in the antibiotic group (P\u0026thinsp;=\u0026thinsp;0.021), representing a nearly five-fold reduction.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSubgroup Analysis by Fecalith Presence\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStratification Standard\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePostoperative WBC(10 ^ 9/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePostoperative CRP (mg/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePostoperative abdominal pain relief time (hour)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHospital stay (day)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eWithout Fecaliths\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT (n\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.22\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.32\u0026thinsp;\u0026plusmn;\u0026thinsp;1.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12.00 (12.00, 24.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.00 (2.00, 4.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAntibiotics\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.49\u0026thinsp;\u0026plusmn;\u0026thinsp;1.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.71\u0026thinsp;\u0026plusmn;\u0026thinsp;11.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.00 (12.00, 36.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.00 (4.00, 5.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eWith Fecaliths\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT (n\u0026thinsp;=\u0026thinsp;18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.35\u0026thinsp;\u0026plusmn;\u0026thinsp;4.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12.00 (10.50,24.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.00 (2.00, 3.25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAntibiotics\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.69\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.80\u0026thinsp;\u0026plusmn;\u0026thinsp;15.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.00 (12.00, 36.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.00 (4.00, 5.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.165\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eSubgroup Analysis: Impact of Baseline Inflammation Severity\u003c/h2\u003e \u003cp\u003eTo further explore the consistency of treatment effects, we stratified patients by baseline CRP level (\u0026le;\u0026thinsp;60 mg/L vs. \u0026gt;60 mg/L), as shown in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. EDAT demonstrated superior outcomes across both strata, with faster symptom relief, shorter hospital stay, and lower postoperative inflammatory markers in all comparisons.\u003c/p\u003e \u003cp\u003eIn patients with mild inflammation (CRP\u0026thinsp;\u0026le;\u0026thinsp;60 mg/L), the recurrence rate was 1/22 (4.5%) in the EDAT group versus 4/21 (19.0%) in the antibiotic group (P\u0026thinsp;=\u0026thinsp;0.354). In patients with moderate-to-severe inflammation (CRP\u0026thinsp;\u0026gt;\u0026thinsp;60 mg/L), the difference was more pronounced and statistically significant: 2/19 (10.5%) versus 10/30 (33.3%) (P\u0026thinsp;=\u0026thinsp;0.042). This suggests that the benefits of EDAT over antibiotics are particularly evident in patients with more severe baseline inflammation.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSubgroup Analysis by Baseline Inflammation Severity\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStratification Standard\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePostoperative WBC(10 ^ 9/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePostoperative CRP (mg/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePostoperative abdominal pain relief time (hour)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHospital stay (day)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePreoperative CRP\u0026le;60mg/L (EDAT n\u0026thinsp;=\u0026thinsp;22; Antibiotics n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.30\u0026thinsp;\u0026plusmn;\u0026thinsp;1.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.81\u0026thinsp;\u0026plusmn;\u0026thinsp;1.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12.00 (10.50, 24.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.00 (2.00, 3.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAntibiotics\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.26\u0026thinsp;\u0026plusmn;\u0026thinsp;1.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.90\u0026thinsp;\u0026plusmn;\u0026thinsp;4.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.00 (12.00, 42.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.00 (3.50, 5.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePreoperative CRP\u0026gt;60mg/L (EDAT n\u0026thinsp;=\u0026thinsp;19; Antibiotics n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEDAT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.45\u0026thinsp;\u0026plusmn;\u0026thinsp;1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.15\u0026thinsp;\u0026plusmn;\u0026thinsp;3.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.00 (12.00,24.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.00 (3.00, 4.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAntibiotics\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.64\u0026thinsp;\u0026plusmn;\u0026thinsp;11.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24.00 (12.00, 36.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.00 (4.00, 5.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.378\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eTo the best of our knowledge, this study provides the first direct comparison between EDAT and antibiotic therapy for AUA. Our findings demonstrate that EDAT offers significant advantages over antibiotics in terms of faster symptom resolution, shorter hospital stay, better control of systemic inflammation, and, most importantly, substantially lower recurrence rates. These benefits were consistent across subgroup analyses stratified by fecalith presence and baseline inflammation severity, suggesting that EDAT's advantages are robust across a spectrum of disease presentations.\u003c/p\u003e \u003cp\u003eThe management of AUA has evolved from a purely surgical paradigm to a more nuanced approach that incorporates both conservative and interventional options[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Antibiotic therapy has gained traction following multiple RCTs demonstrating its feasibility[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The APPAC trial reported 1-year treatment success of 72.7% with antibiotics[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], while the CODA trial found that 29% of patients randomized to antibiotics underwent appendectomy within one year[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. A recent meta-analysis by Salminen et al. confirmed that while antibiotics are effective in the short term, long-term recurrence remains a significant concern, exceeding 30% at five years[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEDAT occupies a unique middle ground between these two extremes. Unlike antibiotics, which rely on the host immune response and spontaneous resolution of obstruction, EDAT provides mechanical relief of luminal obstruction through direct visualization, irrigation, and fecalith removal when present[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. This mechanistic difference likely explains the superior outcomes observed in our study, particularly the dramatic reduction in recurrence compared to antibiotics (7.3% vs. 27.5%). Our recurrence rate for EDAT aligns closely with the 7\u0026ndash;10% reported for ERAT-like techniques in a recent network meta-analysis[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], while the antibiotic recurrence rate is consistent with the 30% figure reported in long-term follow-up studies[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur subgroup analysis identified fecalith presence as the most important factor influencing outcomes, particularly in the antibiotic group. Among patients with fecaliths treated with antibiotics, the recurrence rate was 54.5% (6/11), compared to only 17.5% (7/40) in those without fecaliths. This finding is consistent with a growing body of evidence suggesting that fecaliths are a marker of more severe disease and a predictor of antibiotic failure[\u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eA post-hoc analysis of the APPAC trial by Haijanen et al. demonstrated that the presence of an appendicolith was associated with a significantly higher risk of treatment failure (hazard ratio [HR] 3.47)[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Similarly, the CODA trial reported that patients with appendicoliths had a higher rate of appendectomy within 90 days (25% vs. 13%)[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Our findings extend these observations by showing that EDAT effectively mitigates this risk: patients with fecaliths treated with EDAT had an 11.1% (2/18) recurrence rate, which was not significantly different from the 4.3% (1/23) rate in patients without fecaliths treated with EDAT (P\u0026thinsp;=\u0026thinsp;0.218).\u003c/p\u003e \u003cp\u003eThis has important clinical implications. For patients presenting with AUA and visible fecaliths on imaging, antibiotic therapy alone may be suboptimal, and early intervention with EDAT should be strongly considered. Conversely, in patients without fecaliths and mild-to-moderate inflammation, antibiotic therapy remains a reasonable first-line option, though patients should be counseled about the approximately 15\u0026ndash;20% recurrence risk.\u003c/p\u003e \u003cp\u003eThe superior inflammatory control observed with EDAT warrants discussion. Post-treatment CRP was nearly three times lower in the EDAT group compared to the antibiotic group (7.89 vs. 21.16 mg/L), and the magnitude of WBC reduction was significantly greater. This difference likely reflects the fundamental distinction between source control (EDAT) and systemic therapy (antibiotics). By directly removing the obstructing nidus and purulent material, EDAT rapidly reduces the bacterial load and intraluminal pressure, leading to faster resolution of the inflammatory cascade[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Antibiotics, while effective against systemic bacterial dissemination, do not address the mechanical obstruction and may take longer to achieve clinical response.\u003c/p\u003e \u003cp\u003eThe faster symptom relief (12 vs. 24 hours) and shorter hospital stay (3 vs. 4 days) associated with EDAT have practical implications for healthcare resource utilization and patient satisfaction. A cost-effectiveness analysis would be valuable to quantify these benefits, though it was beyond the scope of this retrospective study.\u003c/p\u003e \u003cp\u003eWe have previously shown that EDAT is superior to LA in terms of recovery speed and inflammatory control, with comparable safety[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The current study extends this evidence by showing that EDAT also outperforms antibiotics, particularly in patients with fecaliths or more severe baseline inflammation. Taken together, these findings position EDAT as a versatile alternative that may be preferable to both surgical and conservative approaches in selected patients.\u003c/p\u003e \u003cp\u003eThe 14.6% stent placement rate in our EDAT cohort is comparable to other published series[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] and reflects the technical reality that complete fecalith removal is not always achievable. Stent placement ensures drainage patency and may reduce the risk of early recurrence, though this requires prospective validation.\u003c/p\u003e \u003cp\u003eOur findings support a stratified approach to treatment selection for AUA. For patients without fecaliths and with mild inflammation (CRP\u0026thinsp;\u0026le;\u0026thinsp;60 mg/L), antibiotic therapy remains a reasonable first-line option, with an expected recurrence rate of approximately 15\u0026ndash;20%. However, patients should be counseled about this risk and offered EDAT if they prioritize faster recovery and lower recurrence. For patients with fecaliths or more severe inflammation (CRP\u0026thinsp;\u0026gt;\u0026thinsp;60 mg/L), antibiotic therapy is associated with a high failure rate (up to 54.5%), and EDAT should be strongly recommended when available.\u003c/p\u003e \u003cp\u003eIt is worth noting that systemic antibiotics were used sparingly in the EDAT group (only 14.6% of patients), whereas all antibiotic group patients received full-course systemic therapy. Despite this, EDAT achieved significantly lower recurrence rates, underscoring the primacy of mechanical source control over systemic antimicrobial therapy alone.\u003c/p\u003e \u003cp\u003eThis study has several limitations that should be acknowledged. First, the retrospective design introduces potential selection bias. The higher prevalence of fecaliths in the EDAT group suggests that clinicians preferentially offered EDAT to patients with more complex disease, which would be expected to bias results against EDAT. Despite this, EDAT demonstrated superior outcomes, strengthening our conclusions. However, unmeasured confounders cannot be excluded.\u003c/p\u003e \u003cp\u003eSecond, the sample size is modest, limiting our ability to detect small differences in some subgroup analyses. The imbalance in fecalith prevalence between groups, while informative, complicates direct comparisons and necessitated stratified analysis.\u003c/p\u003e \u003cp\u003eThird, the follow-up duration differed between groups, with the antibiotic group having longer follow-up (14.9 vs. 7.9 months). This difference would tend to favor antibiotics in terms of recurrence detection, yet EDAT still demonstrated significantly lower recurrence rates, reinforcing the robustness of this finding.\u003c/p\u003e \u003cp\u003eFourth, the antibiotic regimens were not standardized, reflecting real-world practice but introducing heterogeneity. However, the consistency of our findings with published RCTs suggests that this heterogeneity did not materially affect conclusions.\u003c/p\u003e \u003cp\u003eFinally, as a single-center study from a tertiary referral center with expertise in EDAT, our findings may not be generalizable to centers without such expertise. The learning curve for EDAT is not trivial, and outcomes may vary with operator experience[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite these limitations, our findings have several important clinical implications. For patients with AUA, particularly those with visible fecaliths or elevated baseline CRP, EDAT offers a compelling alternative to both surgery and antibiotics. It provides the benefits of organ preservation with faster recovery than surgery and lower recurrence than antibiotics.\u003c/p\u003e \u003cp\u003eFor clinical practice, our results support a stratified approach to treatment selection. Patients without fecaliths and mild inflammation may reasonably choose between antibiotics and EDAT, with antibiotics offering a non-invasive option and EDAT providing faster recovery and lower recurrence. Patients with fecaliths or more severe inflammation should be counseled about the higher risk of antibiotic failure and recurrence, and EDAT should be strongly recommended when available.\u003c/p\u003e \u003cp\u003eFuture research should focus on: (1) large-scale, multicenter randomized controlled trials comparing EDAT with both antibiotics and surgery, with long-term follow-up to 3\u0026ndash;5 years; (2) development of validated prediction models to identify patients most likely to benefit from each treatment approach; (3) cost-effectiveness analyses to inform healthcare policy; (4) standardization of EDAT technique and training to ensure reproducible outcomes across centers[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThis study provides the first evidence comparing EDAT with antibiotic therapy for acute uncomplicated appendicitis. EDAT offers faster symptom resolution, shorter hospital stay, better inflammatory control, and significantly lower recurrence rates compared to antibiotics alone. The presence of fecaliths and elevated baseline CRP identify subgroups of patients at particularly high risk of antibiotic failure who may derive the greatest benefit from EDAT. These findings support the integration of EDAT into the therapeutic armamentarium for AUA as an organ-preserving alternative that occupies a unique and valuable niche between conservative management and surgical resection. Prospective randomized trials are needed to confirm these findings and establish the optimal role of EDAT in clinical practice.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eChen LP: study concept and design, data collection, manuscript drafting, statistical analysis; Zhou F: data collection, manuscript revision; Cheng QR: data collection, follow-up; Feng YL: endoscopic procedures, critical revision. All authors approved the final version.\u003c/p\u003e\u003cp\u003eDisclosure statement\u003c/p\u003e\n\u003cp\u003eDrs. Li-peng Chen, Feng Zhou, Qi-run Cheng, Yu-liang Feng have no conflicts of interest or financial ties to disclose.\u003c/p\u003e\n\u003cp\u003eHuman Ethics and Consent to Participate declarations\u003c/p\u003e\n\u003cp\u003eEthical committee approval was received from the Ethics Committee of Zhejiang Hospital (Approval no: ZJHIRB-003K). Waiver of informed consent was obtained due to the retrospective nature of the study, as approved by the Ethics Committee of Zhejiang Hospital.\u003c/p\u003e\n\u003cp\u003eFunding declarations\u003c/p\u003e\n\u003cp\u003eThe authors declared that this study has received no financial support.\u003c/p\u003e\n\u003cp\u003eData Availability Statement\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy and ethical restrictions, as they contain information that could compromise the privacy of research participants.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eStewart B, Khanduri P, McCord C et al (2014) Global disease burden of conditions requiring emergency surgery. Br J Surg 101(1):e9\u0026ndash;22. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/bjs.9329\u003c/span\u003e\u003cspan address=\"10.1002/bjs.9329\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoris D, Paulson EK, Pappas TN (2021) Diagnosis and management of acute appendicitis in adults: A review. JAMA 326(22):2299\u0026ndash;2311. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jama.2021.20502\u003c/span\u003e\u003cspan address=\"10.1001/jama.2021.20502\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVitetta L, Chen J, Clarke S (2019) The vermiform appendix: an immunological organ sustaining a microbiome inoculum. 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World J Emerg Surg 19(1):15. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s13017-024-00545-2\u003c/span\u003e\u003cspan address=\"10.1186/s13017-024-00545-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-colorectal-disease","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijcd","sideBox":"Learn more about [International Journal of Colorectal Disease](http://link.springer.com/journal/384)","snPcode":"384","submissionUrl":"https://submission.nature.com/new-submission/384/3","title":"International Journal of Colorectal Disease","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Appendicitis, Endoscopic direct-vision appendicitis therapy, Anti-bacterial agents, Recurrence, Fecalith","lastPublishedDoi":"10.21203/rs.3.rs-9039444/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9039444/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBACKGROUND\u003c/h2\u003e \u003cp\u003eEndoscopic direct-vision appendicitis therapy (EDAT) is an emerging ultra-minimally invasive technique for acute uncomplicated appendicitis (AUA). Although laparoscopic appendectomy (LA) is definitive and antibiotic therapy is non-invasive, the comparative efficacy of EDAT versus antibiotics alone remains unclear.\u003c/p\u003e\u003ch2\u003ePURPOSE\u003c/h2\u003e \u003cp\u003eTo compare the short-term outcomes and recurrence rates of EDAT versus antibiotic therapy in patients with AUA.\u003c/p\u003e\u003ch2\u003eMETHODS\u003c/h2\u003e \u003cp\u003eThis retrospective cohort study included 92 patients with AUA treated at a tertiary center: 41 who underwent EDAT between December 2023 and December 2024 and 51 who received antibiotic therapy between December 2023 and December 2024. Clinical outcomes, including symptom relief, hospital stay, inflammatory markers, treatment success, and recurrence, were compared. Subgroup analyses were performed based on the presence of fecaliths and baseline inflammation severity.\u003c/p\u003e\u003ch2\u003eRESULTS\u003c/h2\u003e \u003cp\u003eBaseline characteristics were comparable between groups (all P\u0026thinsp;\u0026gt;\u0026thinsp;0.05), except for a significantly higher prevalence of fecaliths in the EDAT group (43.9% vs. 21.6%, P\u0026thinsp;=\u0026thinsp;0.022). EDAT was associated with significantly faster abdominal pain relief [median 12.0 (IQR 12.0\u0026ndash;24.0) h vs. 24.0 (12.0\u0026ndash;36.0) h, P\u0026thinsp;=\u0026thinsp;0.008], shorter hospital stay [3.0 (2.0\u0026ndash;3.5) days vs. 4.0 (3.0\u0026ndash;5.0) days, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001], and lower postoperative inflammatory markers (WBC: 6.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39 vs. 8.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87 \u0026times;10⁹/L, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001; CRP: 7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.98 vs. 21.16\u0026thinsp;\u0026plusmn;\u0026thinsp;12.21 mg/L, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Initial treatment success was 100% in both groups (EDAT: 41/41, antibiotics: 51/51; P\u0026thinsp;=\u0026thinsp;1.000). At a mean follow-up of 7.88\u0026thinsp;\u0026plusmn;\u0026thinsp;3.52 months (EDAT) and 14.92\u0026thinsp;\u0026plusmn;\u0026thinsp;2.61 months (antibiotics), recurrence rates were 7.3% (3/41) vs. 27.5% (14/51), respectively (P\u0026thinsp;=\u0026thinsp;0.014). Subgroup analyses confirmed that EDAT's advantages were consistent across patients with and without fecaliths, as well as across different levels of baseline inflammation severity.\u003c/p\u003e\u003ch2\u003eCONCLUSION\u003c/h2\u003e \u003cp\u003eIn selected patients with AUA, EDAT offers faster recovery, better inflammatory control, and significantly lower recurrence rates than antibiotic therapy. The presence of fecaliths and elevated baseline CRP predicts antibiotic failure, suggesting that EDAT may be particularly advantageous in these subgroups.\u003c/p\u003e","manuscriptTitle":"Endoscopic Direct-vision Therapy vs. Antibiotics for Acute Uncomplicated Appendicitis: A Retrospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-13 07:40:09","doi":"10.21203/rs.3.rs-9039444/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-26T15:45:38+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-26T08:46:35+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-22T10:38:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"130671268606224020307649489833963842639","date":"2026-03-18T16:11:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"265697480538899221086009264686071483904","date":"2026-03-17T18:24:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"330927594114948273385982618982106151353","date":"2026-03-16T21:43:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"11722463014659598336136273947919111996","date":"2026-03-16T21:39:12+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-09T08:20:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"28993885160398884069559835397180097817","date":"2026-03-08T23:25:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-08T23:10:23+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-06T05:17:16+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-06T05:16:09+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Journal of Colorectal Disease","date":"2026-03-05T11:11:14+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-colorectal-disease","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijcd","sideBox":"Learn more about [International Journal of Colorectal Disease](http://link.springer.com/journal/384)","snPcode":"384","submissionUrl":"https://submission.nature.com/new-submission/384/3","title":"International Journal of Colorectal Disease","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"bec0a145-6332-462f-9bb1-2605091239f3","owner":[],"postedDate":"March 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T16:10:29+00:00","versionOfRecord":{"articleIdentity":"rs-9039444","link":"https://doi.org/10.1007/s00384-026-05136-4","journal":{"identity":"international-journal-of-colorectal-disease","isVorOnly":false,"title":"International Journal of Colorectal Disease"},"publishedOn":"2026-04-29 15:57:26","publishedOnDateReadable":"April 29th, 2026"},"versionCreatedAt":"2026-03-13 07:40:09","video":"","vorDoi":"10.1007/s00384-026-05136-4","vorDoiUrl":"https://doi.org/10.1007/s00384-026-05136-4","workflowStages":[]},"version":"v1","identity":"rs-9039444","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9039444","identity":"rs-9039444","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}