[Therapeutic effectiveness of modified endoscopic retrograde appendicitis therapy for acute appendicitis of different severities in children].

Objective: To investigate the effects of modified endoscopic retrograde appendicitis therapy (mERAT) on the treatment of children with different severities of acute appendicitis. Methods: This study was a case-control study. A total of 586 children with acute appendicitis, who were admitted to the Pediatric Department of Second Affiliated Hospital of Air Force Medical University between January 2019 and November 2023, were selected as the research subjects. According to the severity of the disease, the patients were divided into simple appendicitis group, suppurative appendicitis group and perforated appendicitis group. The baseline data, hospitalization treatment and costs, outcomes, and recurrence in each group were analyzed, and the difference in the effectiveness of mERAT between the groups were compared by Kruskal-Wallis H test and χ2 test. Results: Among 586 children, there were 338 males and 248 females. The age at onset was 7.0 (4.6, 9.4) years. There were 475 cases of simple appendicitis, 78 cases of suppurative appendicitis, and 33 cases of perforated appendicitis. There were no significant differences in age and gender among the three groups (F=0.59, χ2=3.31, both P>0.05). However, there were statistically significant differences in body temperature, white blood cell counts, neutrophil percentage, lymphocyte percentage, nausea or vomiting, right lower abdominal pain, umbilical pain, right lower abdominal tenderness, and right lower abdominal rebound pain (H=7.56, 161.52, 169.11, and 169.61, χ2=12.05, 13.82, 12.05, 7.74, 20.35, and 94.61, all P<0.05). Also, the treatment time, postoperative hospital stay, total hospital stay, and cost showed statistically significant differences (H=4.70, 33.66, 34.99, 30.37, all P<0.05). There was no significant difference in the initial treatment success rate (98.1% (466/475) vs. 98.7% (77/78) vs. 90.9% (30/33), P=0.057). During the 30 (23, 36) months of follow-up, the recurrence rate was 7.9% (35/433) in the simple appendicitis group, 20.8% (15/72) in the suppurative appendicitis group, and 30.0% (9/30) in the perforated appendicitis group, with a statistically significant difference (χ2=23.56, P<0.001). Among the children with recurrent appendicitis, 15 cases still chose mERAT, of them 11 cases (31.2%) had simple appendicitis, 2 cases (2/15) had suppurative appendicitis, and 2 cases (2/9) had perforated appendicitis.The latest time to recurrence in the 3 groups was 32, 35 and 10 months, respectively. Conclusion: Treatment with mERAT has a good effect in pediatric simple appendicitis, but has a higher recurrence rate despite a better initial treatment success rate in suppurative appendicitis and perforated appendicitis.

Mucocoele of the appendix.

Introduction: Mucocoele of the appendix occurs in 0.2-0.7% of people in the world without any well-defined clinical symptoms. It occurs when there is an accumulation of mucous in the lumen of the appendix. Case Presentation: We present three cases: a 48-year-old male admitted to the emergency room with a one-day history of right iliac fossa pain. Abdominal examination was suggestive of acute appendicitis. The initial abdominal computerised tomography scan was reported as being unremarkable. At surgery, a firm tumour of the appendix was found, and a limited right hemicolectomy was done. Histopathology confirmed a mucocoele of the appendix with borderline mucinous histology.The second case is a 63-year-old man who presented with a one-year history of abdominal distension and weight loss. Previous abdominal ultrasound was suggestive of liver cirrhosis with significant ascitic fluid. Abdominal magnetic resonance imaging found an appendix mucocoele with infiltration of the omentum and scalloping of the liver surface suggestive of pseudomyxoma peritonei. A percutaneous biopsy of the omental mass confirmed metastatic mucinous adenocarcinoma of the appendix.The third case is a 68-year-old man who, during an annual medical check-up, had an incidental finding of a cystic right iliac fossa mass on ultrasound, confirmed on abdominopelvic computerised tomography scan to be an appendix mucocele. He had laparoscopic appendicectomy. The histopathological diagnosis confirmed a mucinous cystadenoma of the appendix. Conclusion: Preoperative diagnosis of appendiceal mucocoele is difficult and commonly discovered intraoperatively. The prognosis is good for the histologically benign type, but it is poor when malignant or peritoneal lesions are present. Funding: None declared.

Leaking Ectopic Pregnancy Following In vitro Fertilization with Associated Acute Appendicitis.

BACKGROUND: Ectopic pregnancy associated with appendicitis is rare, with very few cases reported in the literature. It is unclear if appendicitis is coincidentally associated with ectopic pregnancy or a possible risk factor for the development of ectopic pregnancy. Ruptured ectopic pregnancy has also been postulated as a possible risk factor leading to appendicitis because of the probable inflammatory reaction involving the adjacent appendix. METHODS: We present a 34-year-old female who presented with right lower abdominal pain and bleeding per vaginam, three weeks after in-vitro fertilization and embryo transfer. RESULTS: A diagnosis of ectopic pregnancy was made following a positive ß-HCG and empty uterine cavity on pelvic ultrasound scan. Intraoperatively, the appendix was noted to be inflammed and it was removed and confirmed on histology examination as acute appendicitis. CONCLUSION: Ruptured ectopic pregnancy associated with acute appendicitis is rare, with few cases reported in the literature. We recommend an examination for other possible differentials of ruptured ectopic pregnancy like appendicitis during surgery for ectopic pregnancy on the right side.

CONTEXTE: L'association de la grossesse extra-utérine avec l'appendicite est rare, avec très peu de cas rapportés dans la littérature. Il n'est pas clair si l'appendicite est associée de manière fortuite à la grossesse extra-utérine ou si elle constitue un facteur de risque possible pour le développement de celle-ci. On a également postulé que la grossesse extra-utérine rompue pourrait être un facteur de risque conduisant à l'appendicite en raison de la probable réaction inflammatoire impliquant l'appendice adjacent. MÉTHODES: Nous présentons le cas d'une femme de 34 ans qui s'est présentée avec une douleur abdominale basse à droite et des saignements vaginaux, trois semaines après une fécondation in vitro et un transfert d'embryon. RÉSULTATS: Un diagnostic de grossesse extra-utérine a été posé suite à un test de ß-HCG positif et une cavité utérine vide à l'échographie pelvienne. En peropératoire, l'appendice a été noté comme étant inflammé et a été retiré. L'examen histologique a confirmé une appendicite aiguë. CONCLUSION: La grossesse extra-utérine rompue associée à une appendicite aiguë est rare, avec quelques cas rapportés dans la littérature. Nous recommandons un examen pour d'autres diagnostics différentiels possibles de la grossesse extra-utérine rompue, comme l'appendicite, lors de la chirurgie pour grossesse extra-utérine du côté droit. MOTS CLÉS: Grossesse extra-utérine hémorragique, Appendicite, Fécondation in vitro, Laparotomie.

Culture-based bacterial evaluation of the appendix lumen and antibiotic susceptibility of acute appendicitis in Japan: A single-center retrospective analysis.

The question of whether to perform an appendectomy or conservative treatment for acute appendicitis can differ depending on the facility or surgeon, but antibiotic treatment is administered regardless of whether an appendectomy or conservative treatment is selected. We investigated the contemporary bacteriology for acute appendicitis and evaluated the antibiotic sensitivity of the bacteria that are currently associated with appendicitis. We retrospectively analyzed the bacterial culture results and antibiotic susceptibility of 141 patients who underwent appendicitis surgery, including the identification and antimicrobial susceptibility of the cultured bacteria within the excised appendices. Bacterial cultures were positive in 131 cases (92.9%). The most commonly isolated bacteria were Escherichia coli (90 isolates, 66.7%), followed by Enterococcus species (n = 19, 14.5%), Pseudomonas aeruginosa (n = 18, 13.7%), Streptococcus species (n = 15, 11.5%), and Klebsiella species (n = 8, 6.1%). Eight strains (8.8%) of E coli were extended-spectrum ß-lactamase producers, and ten strains (11.1%) were fluoroquinolone-resistant. Tazobactam/piperacillin and meropenem inhibited the growth of 100% of the major identified bacteria. The patients with appendicoliths had a significantly higher bacterial culture rate. Enterococcus species were frequently isolated from the patients with complicated appendicitis. For the antibiotic treatment of appendicitis, it is essential to understand the patient's microbiological profile and antibiotic susceptibilities. Research from Asian countries such as Japan can enhance our knowledge of regional antibiotic resistance patterns and inform effective treatment strategies.

The implementation of the acute care surgery model in the management of patients with acute appendicitis - A 5-year single-center, retrospective experience: An observational study.

We conducted this study to assess the effects of the acute care surgery (ACS) model in the management of patients with acute appendicitis (AA) based on our 5-year single-center, retrospective experience. The current single-center, retrospective, observational study was conducted in a consecutive series of the patients with AA who had been surgically treated at a tertiary referral hospital in Seoul, Korea, between January 2016 and December 2020. At our institution, the ACS model was first introduced in March 2018. Therefore, our clinical series of the patients were divided into 2 groups: the pre-ACS group (March 2014 to February 2018) and the post-ACS group (March 2018 to December 2022). Key time intervals include emergency department registration to request for surgical consultation, request for surgical consultation to decision on surgery, decision-to-operating room, time to decision on surgery and length of emergency department stay. Moreover, outcomes include rates of perforation and complications and discharge within 24 or 48 hours. We compared key time intervals, outcomes, and length of hospital stay between the 2 groups. A total of 900 patients with AA were finally included in the current study, 447 and 453 of whom were divided into the pre-ACS group (n = 447) and the post-ACS group (n = 453), respectively. There were significant differences in key time intervals, outcomes, and length of hospital stay between the 2 groups (P < .05). In conclusion, our results showed that the implementation of the ACS model was effective in improving key time intervals, rates of perforation, and discharge within 24 or 48 hours in the patients with AA.

How can the surgeon choose preoperatively the most appropriate antibiotic prophylaxis vs therapy in pediatric acute appendicitis?

INTRODUCTION: The aim of this study was to find statistically valid criteria to preoperatively divide acute appendicitis into simple and complicated to enable surgeons to administer the most appropriate antibiotic prophylaxis/therapy before surgery. MATERIALS AND METHODS: We retrospectively reviewed a cohort of patients who underwent appendectomy from January 2022 to December 2023. Patients included were 0-14 years of age. Exclusion criteria included patients who underwent interval appendectomy or concurrent procedures at the same time of appendectomy. We divided patients into two groups: simple (group S) and complicated (group C) appendicitis according to intraoperative finding. Generalized linear model (GLM) with logit function was developed to identify the predictive variables of the type of appendicitis (S vs C) in terms of CRP value, neutrophils percentage and WBC count adjusted for age and sex of patients. Finally, principal component analysis (PCA) was carried out to identify the cutoff value of statistically significant variables found in the previous analysis. RESULTS: One hundred and twenty patients were eligible (N female = 49, N male = 71) for the study. 74 and 46 patients were included in groups S and C, respectively. In a preliminary analysis using univariate and multivariate GLM, only CRP (p value = < 0.001) and neutrophils percentage (p value = 0.02) were predictive variables for the type of appendicitis. The GLM shows a statistical lower value of CRP (adjusted odds ratio [OR] per unit, 0.17 [95% CI, 0.08-0.39]) and neutrophil percentage (adjusted OR per unit, 0.37 [95% CI, 0.16-0.86]) in the S group compared to C adjusted to age and sex. PCA analysis revealed a P-ROC cutoff of 4.2 mg/dl and 80.1 of CRP value (AUC = 84%) and neutrophil percentage (AUC = 70%), respectively. CONCLUSIONS: We will perform a prospective study giving preoperative prophylactic cefazolin to patients with a CRP value under 4.2 mg/dl and amoxicillin-clavulanate therapy to patient with CRP value over 4.2 mg/dl.

The diagnostic value of serum hepcidin in acute appendicitis.

BACKGROUND: Acute appendicitis (AA) is the primary cause of acute abdomen in patients presenting to the emergency department with abdominal pain. Limited studies have explored the relationship between serum hepcidin levels and AA. This study aimed to measure serum hepcidin levels in patients undergoing surgery with a preliminary diagnosis of AA and to assess whether these levels can serve as a biochemical marker for diagnosing AA. METHODS: This study included patients aged 18 or older who presented to the emergency department between April 2018 and May 2019 and underwent surgery with a diagnosis of AA. The cohort comprised 94 patients with surgical pathology results compatible with AA (Group A), 16 patients with results not compatible with AA (Group B), and 42 healthy controls. Serum hepcidin levels were measured from venous blood samples. RESULTS: Mean hepcidin levels were 1750±285 pg/mL in Group A, 1349±381 pg/mL in Group B, and 1066±225 pg/mL in the control group. Statistically significant differences in serum hepcidin levels were observed between Group A and the control group (p<0.05). CONCLUSION: Hepcidin levels were significantly higher in patients with AA compared to both the control group and patients with surgically confirmed non-AA pathology. Therefore, hepcidin may serve as a useful adjunct in diagnosing acute appendicitis.

Construction of a clinical prediction model for complicated appendicitis based on machine learning techniques.

Acute appendicitis is a typical surgical emergency worldwide and one of the common causes of surgical acute abdomen in the elderly. Accurately diagnosing and differentiating acute appendicitis can assist clinicians in formulating a scientific and reasonable treatment plan and providing high-quality medical services for the elderly. In this study, we validated and analyzed the different performances of various machine learning models based on the analysis of clinical data, so as to construct a simple, fast, and accurate estimation method for the diagnosis of early acute appendicitis. The dataset of this paper was obtained from the medical data of elderly patients with acute appendicitis attending the First Affiliated Hospital of Anhui University of Chinese Medicine from January 2012 to January 2022, including 196 males (60.87%) and 126 females (39.13%), including 103 (31.99%) patients with complicated appendicitis and 219 (68.01%) patients with uncomplicated appendicitis. By comparing and analyzing the prediction results of the models implemented by nine different machine learning techniques (LR, CART, RF, SVM, Bayes, KNN, NN, FDA, and GBM), we found that the GBM algorithm gave the optimal results and that sensitivity, specificity, PPV, NPV, precision, recall, F1 and brier are 0.9167, 0.9739, 0.9429, 0.9613, 0.9429, 0.9167, 0.9296, and 0.05649, respectively. The GBM model prediction results are interpreted using the SHAP technology framework. Calibration and Decision curve analysis also show that the machine learning model proposed in this paper has some clinical and economic benefits. Finally, we developed the Shiny application for complicated appendicitis diagnosis to assist clinicians in quickly and effectively recognizing patients with complicated appendicitis (CA) and uncomplicated appendicitis (UA), and to formulate a more reasonable and scientific clinical plan for acute appendicitis patient population promptly.

Diagnostic value of systemic immune inflammation index in acute appendicitis and complicated appendicitis in pregnant patients.

INTRODUCTION: Acute pain in the right lower quadrant during pregnancy is difficult to approach and acute appendicitis must be excluded. The complication rate in pregnant acute appendicitis increases as a result of delayed diagnosis due to physiological and anatomic changes. The systemic immune inflammatory index (SII), which includes several inflammatory tests, is considered to be a good indicator of acute inflammation. The aim of the present study was to investigate the diagnostic value of SII in the diagnosis of acute appendicitis and complicated appendicitis in pregnant women. MATERIAL-METHOD: This was designed as a retrospective, single-center case-control study. This study was performed in pregnant women over 12 weeks of gestation who were diagnosed with acute appendicitis as indicated by pathology report and met the inclusion criteria. Vital parameters, demographic characteristics, laboratory values, presence of complicated appendicitis, and pathology reports were taken into analysis. RESULTS: The present study was performed with 76 pregnant women, including 38 pregnant women with acute appendicitis and 38 pregnant women with healthy controls. SII had a sensitivity of 82.0% and specificity of 66.7% with a cut-off value of 840.13 in pregnant acute appendicitis cases (AUC: 0.790; 95% CI: 0.686-0.984; p < 0.001) and SII level was significantly higher in complicated appendicitis cases with a sensitivity and specificity of 66.7% and 91.3%, respectively, with a cut-off value of 2301.66 (AUC: 0.812; 95% CI: 0.665-0.958; p = 0.001). CONCLUSION: SII is a cost-effective, rapid, easily calculated, and powerful marker that can be used for the diagnosis of both acute and complicated appendicitis in pregnant patients.

[Appendix ... it's not just appendicitis: neuroendocrine tumors.] / L'appendice... non è solo appendicite: i tumori neuroendocrini.

Well-differentiated neuroendocrine tumors of the appendix (NETs) are rare in pediatric and adolescent age groups. However, they are the most common gastrointestinal epithelial tumor in this age group and the most common malignancy of the appendix in the general population. The classification of these tumors considers factors such as the proliferation index, size of the neoplasm, and the presence of perineural and/or lymphovascular invasion, which can contribute to distant metastases. Preoperative diagnosis is challenging, except in cases where patients exhibit symptoms of carcinoid syndrome or signs of metastatic disease, which are uncommon in pediatric and adolescent patients. For tumors smaller than 1 cm, appendectomy is usually curative, while larger tumors or those at risk of spreading may require right hemicolectomy with lymphadenectomy. We present a case of an adolescent with NET and provide a literature review on the diagnostic and therapeutic approaches that should be considered for this relatively rare condition.Key words. Adolescent age, appendix, neuroendocrine tumors, pediatric age.

Mining and exploration of appendicitis nursing targets: An observational study.

Appendicitis is an inflammation caused by obstruction of the appendiceal lumen or termination of blood supply leading to appendiceal necrosis followed by secondary bacterial infection. The relationship between TYROBP gene and the nursing of appendicitis remains unclear. The appendicitis dataset GSE9579 profile was downloaded from the gene expression omnibus database generated from GPL571. Differentially expressed genes were screened, followed by weighted gene co-expression network analysis, functional enrichment analysis, gene set enrichment analysis, construction and analysis of protein-protein interaction network, Comparative Toxicogenomics Database analysis, and immune infiltration analysis. Heatmaps of gene expression levels were plotted. A total of 1570 differentially expressed genes were identified. According to gene ontology analysis, they were mainly enriched in organic acid metabolic process, condensed chromosome kinetochore, oxidoreductase activity. In Kyoto Encyclopedia of Gene and Genome analysis, they mainly concentrated in metabolic pathways, P53 signaling pathway, PPAR signaling pathway. The soft threshold power in weighted gene co-expression network analysis was set to 12. Through the construction and analysis of protein-protein interaction network, 5 core genes (FCGR2A, IL1B, ITGAM, TLR2, TYROBP) were obtained. Heatmap of core gene expression levels revealed high expression of TYROBP in appendicitis samples. Comparative Toxicogenomics Database analysis found that core genes (FCGR2A, IL1B, ITGAM, TLR2, TYROBP) were closely related to abdominal pain, gastrointestinal dysfunction, fever, and inflammation occurrence. TYROBP gene is highly expressed in appendicitis, and higher expression of TYROBP gene indicates worse prognosis. TYROBP may serve as a molecular target for appendicitis and its nursing.

Low Pressure versus Standard Pressure Pneumoperitoneum in Laparoscopic Appendectomy: A Randomized Controlled Trial.

BACKGROUND: The creation of pneumoperitoneum using higher pressure is believed to be associated with increased postoperative abdominal pain. AIM: This study aimed to compare postoperative abdominal pain following low pressure laparoscopic appendectomy and standard pressure laparoscopic appendectomy. METHODS: This was a prospective, double-blind, randomized controlled trial of 54 patients aged between 18 and 56 years with clinical and/or radiologic diagnosis of acute appendicitis. The patients were randomly allocated to two groups: low pressure laparoscopic appendectomy (n = 26) and standard pressure laparoscopic appendectomy (n = 28). The intra-abdominal pressure was kept in either low pressure (9 mm Hg) or standard pressure (13 mm Hg). Abdominal and shoulder pain scores were assessed using the visual analog scale at 6 hours and 3 days post procedure. Postoperative analgesia requirement, duration of surgery, complications, and hospital stay were recorded. RESULTS: Both groups match for the demographic parameters. Three patients required conversion from low to standard pressure. There was no difference between the two groups in terms of abdominal pain (P = 0.86) and shoulder pain (P = 0.33), duration of surgery (P = 0.51), complications (P = 0.17), and length of hospital stay (P = 0.83). CONCLUSION: The use of low pressure pneumoperitoneum did not reduce the incidence of abdominal pain in patients who had laparoscopic appendectomy. Patients with acute appendicitis can be treated with either low or normal pressure pneumoperitoneum depending on the experience of the surgeon.

MAIT cell activation and recruitment in inflammation and tissue damage in acute appendicitis.

Mucosal-associated invariant T (MAIT) cells are antimicrobial T cells abundant in the gut, but mechanisms for their migration into tissues during inflammation are poorly understood. Here, we used acute pediatric appendicitis (APA), a model of acute intestinal inflammation, to examine these migration mechanisms. MAIT cells were lower in numbers in circulation of patients with APA but were enriched in the inflamed appendix with increased production of proinflammatory cytokines. Using the patient-derived appendix organoid (PDAO) model, we found that circulating MAIT cells treated with inflammatory cytokines elevated in APA up-regulated chemokine receptors, including CCR1, CCR3, and CCR4. They exhibited enhanced infiltration of Escherichia coli-pulsed PDAO in a CCR1-, CCR2-, and CCR4-dependent manner. Close interactions of MAIT cells with infected organoids led to the PDAO structural destruction and death. These findings reveal a previously unidentified mechanism of MAIT cell tissue homing, their participation in tissue damage in APA, and their intricate relationship with mucosal tissues during acute intestinal inflammation in humans.

Evaluation of geographic variations in appendicectomy outcomes within Western Australia assessing the impact of surgical wait times and rate of negative appendicectomies in both urban and rural locations statewide.

PURPOSE: Surgery wait times after diagnosis of appendicitis are an important factor influencing the success of a patient's treatment. The proposed study will be a quantitative multicenter retrospective cohort design with the primary aim of assessing the difference between appendicectomy wait times between rural and urban hospitals in Western Australia and the effect of this on operative outcomes. Selected outcome measures will be examined by time from initial presentation at an emergency department to the patient being diagnosed and then time of diagnosis to surgery being performed. The secondary aim is to compare rates of negative appendicectomies between hospitals. METHODS: Appendicectomy patients will be identified from operating room register by medical student data collectors; then, each respective hospital's emergency room data collection will subsequently be accessed to complete case report forms based on demographics and clinical findings, pre-operative investigations, and management and follow-up. Case report forms with > 95% completeness will be accepted for pooled analysis. The expected duration of retrospective data collection will be 8 months. This study RGS6483 has received HREC approval by the Royal Perth Hospital HREC Ethics Committee, with a waiver of consent obtained and the HREC was notified of amendments to the protocol made on April 21, 2024. Dissemination of results. Data will be collected and stored online through a secure server running the Research Electronic Data Capture (REDCap) web application. No patient-identifiable data will be entered into the system. Results will subsequently be shared via scientific journal publication and presentation at relevant meetings.

Incidence, Predictors, and Outcomes of Pseudomonas aeruginosa Associated Acute Appendicitis in Children.

BACKGROUND: Pseudomonas aeruginosa (PSA) is an infectious pathogen associated with acute appendicitis; however, it is not consistently addressed by empirical antibiotic therapy, despite potential complications. OBJECTIVES: To investigate the incidence, predictors, and outcomes of PSA-associated acute appendicitis in children. METHODS: We conducted a retrospective analysis involving pediatric patients who underwent acute appendicitis surgery and had positive peritoneal cultures. Clinical, microbiological, and intraoperative data were extracted from medical records. RESULTS: Among 2523 children with acute appendicitis, 798 (31.6%) underwent peritoneal cultures, revealing 338 positive cases (42.3%), with PSA detected in 77 cases (22.8%). Children with PSA were three times more likely to exhibit high intraoperative grading ≥ 3 (93.4% vs. 76.8%, 95% confidence interval [95%CI] 1.2-8.3, P = 0.023) and nearly four times more likely to have polymicrobial cultures (88.3% vs. 62.1%, 95%CI 1.8-8.0, P < 0.001) than those without PSA in peritoneal cultures. Duration of symptoms did not predict PSA isolation (P = 0.827). Patients with PSA had longer median hospital stays (8 days, interquartile range [IQR] 7-10) than those with other pathogens (7 days, IQR 5-9) (P = 0.004). Antibiotic treatment duration, intensive care unit admission rates, readmission, and mortality were similar between the two groups (P = 0.893, 0.197, 0.760, and 0.761, respectively). CONCLUSIONS: PSA is a common pathogen in children diagnosed with acute appendicitis and positive peritoneal cultures. The likelihood of isolating PSA increases with high-grade intraoperative assessment and in the presence of multiple pathogens in peritoneal cultures, suggests antipseudomonal treatment.

Antibiotic treatment after appendectomy for acute complicated appendicitis to prevent intrabdominal abscess and wound infections.

INTRODUCTION: The purpose of this analysis was to investigate the most appropriate duration of postoperative antibiotic treatment to minimize the incidence of intraabdominal abscesses and wound infections in patients with complicated appendicitis. MATERIALS AND METHODS: In this retrospective study, which included 396 adult patients who underwent appendectomy for complicated appendicitis between January 2010 and December 2020 at the University Hospital Erlangen, patients were classified into two groups based on the duration of their postoperative antibiotic intake: ≤ 3 postoperative days (group 1) vs. ≥ 4 postoperative days (group 2). The incidence of postoperative intraabdominal abscesses and wound infections were compared between the groups. Additionally, multivariate risk factor analysis for the occurrence of intraabdominal abscesses and wound infections was performed. RESULTS: The two groups contained 226 and 170 patients, respectively. The incidence of postoperative intraabdominal abscesses (2% vs. 3%, p = 0.507) and wound infections (3% vs. 6%, p = 0.080) did not differ significantly between the groups. Multivariate analysis revealed that an additional cecum resection (OR 5.5 (95% CI 1.4-21.5), p = 0.014) was an independent risk factor for intraabdominal abscesses. A higher BMI (OR 5.9 (95% CI 1.2-29.2), p = 0.030) and conversion to an open procedure (OR 5.2 (95% CI 1.4-20.0), p = 0.016) were identified as independent risk factors for wound infections. CONCLUSION: The duration of postoperative antibiotic therapy does not appear to influence the incidence of postoperative intraabdominal abscesses and wound infections. Therefore, short-term postoperative antibiotic treatment should be preferred.

Applying an explainable machine learning model might reduce the number of negative appendectomies in pediatric patients with a high probability of acute appendicitis.

The diagnosis of acute appendicitis and concurrent surgery referral is primarily based on clinical presentation, laboratory and radiological imaging. However, utilizing such an approach results in as much as 10-15% of negative appendectomies. Hence, in the present study, we aimed to develop a machine learning (ML) model designed to reduce the number of negative appendectomies in pediatric patients with a high clinical probability of acute appendicitis. The model was developed and validated on a registry of 551 pediatric patients with suspected acute appendicitis that underwent surgical treatment. Clinical, anthropometric, and laboratory features were included for model training and analysis. Three machine learning algorithms were tested (random forest, eXtreme Gradient Boosting, logistic regression) and model explainability was obtained. Random forest model provided the best predictions achieving mean specificity and sensitivity of 0.17 ± 0.01 and 0.997 ± 0.001 for detection of acute appendicitis, respectively. Furthermore, the model outperformed the appendicitis inflammatory response (AIR) score across most sensitivity-specificity combinations. Finally, the random forest model again provided the best predictions for discrimination between complicated appendicitis, and either uncomplicated acute appendicitis or no appendicitis at all, with a joint mean sensitivity of 0.994 ± 0.002 and specificity of 0.129 ± 0.009. In conclusion, the developed ML model might save as much as 17% of patients with a high clinical probability of acute appendicitis from unnecessary surgery, while missing the needed surgery in only 0.3% of cases. Additionally, it showed better diagnostic accuracy than the AIR score, as well as good accuracy in predicting complicated acute appendicitis over uncomplicated and negative cases bundled together. This may be useful in centers that advocate for the conservative treatment of uncomplicated appendicitis. Nevertheless, external validation is needed to support these findings.