Complicated Appendicitis: Are Extended Antibiotics Necessary? A Post Hoc Analysis of the EAST Appendicitis "MUSTANG" Study

Risk Factors for Postoperative Infections Following Appendectomy of Complicated Appendicitis: A Meta-analysis and Retrospective Single-institutional Study

Patients with complicated appendicitis have an increased risk for postoperative infections. Potential risk factors for postoperative infections through a meta-analysis and retrospective chart review are discussed. A meta-analysis consisting of 35 studies analyzing complicated appendicitis treated with an appendectomy noting at least 1 postoperative infection was performed. A retrospective review was then conducted in patients diagnosed with complicated appendicitis after appendectomy. Of 5326 patients in total, 15.4% developed postoperative infections. Laparoscopic surgery and perioperative hyperoxygenation were found to be protective factors for the development of infection. Retrospectively, 53.2% of patients presented with complicated appendicitis. Patients with complicated appendicitis were more likely to be older in age and have an increased length of stay. Patient demographics, operative time, and comorbid status had no effect on postoperative infection or readmission rate. Physicians should strongly consider minimally invasive techniques to treat all cases of complicated appendicitis irrespective of comorbidities, age, sex, or body mass index.

Intraoperative bacterial cultures fail to reliably predict the bacterial spectrum encountered during infectious complications after appendicitis

Acute appendicitis is a common surgical emergency. Complicated appendicitis usually warrants perioperative antibiotic treatment in order to prevent infectious complications. Whether routine microbiological testing benefits the individual patient is a topic of debate. The goal of our study was to assess perioperative antibiotic prescriptions as well as the benefit of microbiological testing during the appendectomy as a predictor for bacteria encountered in infectious complications. This is a retrospective analysis of 1218 consecutive patients that underwent appendectomy at a tertiary referral center between 2014 and 2021. The patient charts were systematically analyzed regarding intraoperative outcome, microbiologic results, and postoperative infectious complications. 1218 patients were included in this study of which 768 were uncomplicated appendicitis (UA) and 450 were complicated appendicitis (CA). Microbiological testing was performed in 39.2% of UA cases (33.6% of which grew bacteria) compared to 74.9% of CA cases (78.6% positive cultures). The strongest individual predictors for SSI were gangrenous and perforated appendicitis. A total of 58 surgical-site infections developed, of which 49 were intra-abdominal fluid collections or abscesses. Thirty-two patients had revision surgery or CT-guided drainage for SSI. In the cases where microbiological testing was done both during the appendectomy and the SSI, 13/18 showed different bacteria on culture testing. The infectious outcome was favorable in 98.3%. While microbiological testing offers insights into resistance patterns, it is of little benefit for the individual patient, given the low predictive value for bacteria found during SSI. Achieving source control combined with empiric antibiotic coverage leads to favorable outcomes independent of culture results.

Diagnosis and treatment of appendicitis: systematic review and meta-analysis

BACKGROUND

The optimal diagnosis and treatment of appendicitis remains controversial. This systematic review details the evidence and current best practices for the evaluation and management of uncomplicated and complicated appendicitis in adults and children.

METHODS

Eight questions regarding the diagnosis and management of appendicitis were formulated. PubMed, Embase, CINAHL, Cochrane and clinicaltrials.gov/NLM were queried for articles published from 2010 to 2022 with key words related to at least one question. Randomized and non-randomized studies were included. Two reviewers screened each publication for eligibility and then extracted data from eligible studies. Random effects meta-analyses were performed on all quantitative data. The quality of randomized and non-randomized studies was assessed using the Cochrane Risk of Bias 2.0 or Newcastle Ottawa Scale, respectively.

RESULTS

2792 studies were screened and 261 were included. Most had a high risk of bias. Computerized tomography scan yielded the highest sensitivity (> 80%) and specificity (> 93%) in the adult population, although high variability existed. In adults with uncomplicated appendicitis, non-operative management resulted in higher odds of readmission (OR 6.10) and need for operation (OR 20.09), but less time to return to work/school (SMD - 1.78). In pediatric patients with uncomplicated appendicitis, non-operative management also resulted in higher odds of need for operation (OR 38.31). In adult patients with complicated appendicitis, there were higher odds of need for operation following antibiotic treatment only (OR 29.00), while pediatric patients had higher odds of abscess formation (OR 2.23). In pediatric patients undergoing appendectomy for complicated appendicitis, higher risk of reoperation at any time point was observed in patients who had drains placed at the time of operation (RR 2.04).

CONCLUSIONS

This review demonstrates the diagnosis and treatment of appendicitis remains nuanced. A personalized approach and appropriate patient selection remain key to treatment success. Further research on controversies in treatment would be useful for optimal management.

The efficacy of hemoglobin, albumin, lymphocytes, and platelets (HALP) score in signifying acute appendicitis severity and postoperative outcomes

The HALP score, which is a combined index composed of hemoglobin, albumin, lymphocyte, and platelet, is a new indicator showing both inflammation and nutritional status. This study aims to evaluate the relationship of this combined index consisting of simple laboratory values with the degree of appendicitis complication and postoperative results in patients operated on for acute appendicitis. The data of 684 patients operated for acute appendicitis between January 2017 and December 2022 and inclusion criteria were analyzed with a single-center retrospective cross-sectional study design. Using routine laboratory data, patients' HALP scores were divided into two groups as low and high. The cut-off value of the HALP score according to the presence of postoperative complications was determined as < 31.2 by ROC analysis and the ROC curve. Patients were grouped as HALP score cut-off value below (group 1) and above (group 2). Complicated appendicitis and postoperative outcomes were compared to the HALP score groups. According to the cut-off value of the HALP score, 113 (16.5%) of the patients were in Group 1, and 571 (83.5%) were in Group 2. Complications developed in 15 (26%) patients (p < 0.001). Low HALP scores were a significant risk factor for peri-appendicular abscess (OR 29.12 95% CI 12.39-68.43), appendicitis perforation (OR = 20.82 95% 12.67-34.19), gangrenous appendicitis (OR = 35, 54, 95% 13.33-94.77), and postoperative complications (OR = 15.29 95% 7.95-29.41) (p < 0.001). Besides clinical and radiological findings, the HALP score shows the degree of acute appendicitis complication. It can be used as a simple, inexpensive, and easily applicable diagnostic tool.

Implications of bacteriological study in complicated and uncomplicated acute appendicitis

Purpose

Bacteriological sample in the presence of intraabdominal free fluid is necessary to adapt the antibiotherapy and to prevent the development of resistance. The aim was to evaluate the differences between uncomplicated (UAA) and complicated acute appendicitis (CAA) in terms of bacterial culture results and antibiotic resistance, and to evaluate the factors linked with CAA.

Methods

We performed a single-center, retrospective observational study of all consecutive patients who presented with appendicular peritonitis and underwent emergent surgery in a tertiary referral hospital in Brussels, Belgium, between January 2013 and December 2020. The medical history, parameters at admission, bacterial culture, antibiotic resistance, and postoperative outcomes of 268 patients were analyzed. UAA was considered catarrhal or phlegmonous inflammation of the appendix. CAA was considered gangrenous or perforated appendicitis.

Results

Positive microbiological cultures were significantly higher in the CAA group (68.2% vs. 53.4%). The most frequently isolated bacteria in UAA and CAA cultures were Escherichia coli (37.9% and 48.6%). Most observed resistances were against ampicillin (28.9% and 21.7%) and amoxicillin/clavulanic acid (16.4% and 10.5%) in UAA and CAA, respectively. A higher Charlson comorbidity index, an elevated white blood cell count, an open procedure, and the need for drainage were linked to CAA. Culture results, group of bacterial isolation, and most common isolated bacteria were not related to CAA.

Conclusion

CAA presented a higher rate of positive cultures with increased identification of gram-negative bacteria. Bacterial culture from the peritoneal liquid does not reveal relevant differences in terms of antibiotic resistance.

Complex And Simple Appendicitis: REstrictive or Liberal postoperative Antibiotic eXposure (CASA RELAX) using Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR): study protocol for a randomized controlled trial

Objectives

After appendectomy for simple or complicated appendicitis, the optimal duration of postoperative antibiotics (postop abx) is unclear and great practice variability exists. We propose to compare restrictive versus liberal postop abx using a hierarchical composite endpoint which includes patient-centered outcomes and accounts for duration of antibiotic exposure.

Methods/Design

Participants with simple or complicated appendicitis undergoing appendectomy are randomly assigned to either restricted or liberal strategy. Eligible subjects declining randomization will be recruited to enroll in an observation only cohort. The primary endpoint is an ordinal scale of mutually exclusive clinical outcomes with within-category rankings determined by duration of antibiotic exposure. Subjects in both randomized and observation only cohorts will be analyzed as intention-to-treat, per-protocol, and as-treated. Exploratory Bayesian analyses will be performed.

Conclusion

The complex and simple appendicitis: restrictive or liberal postoperative antibiotic exposure multicenter randomized controlled trial will enroll surgical appendectomy patients and seeks to analyze if a strategy of restricted (compared with liberal) postoperative antibiotics results in similar clinical outcomes with the benefit of reduced antibiotic exposure.

Trial registration number

NCT05002829.

Outcomes of Restricted versus Liberal Post-Operative Antibiotic Use in Patients Undergoing Appendectomy: A DOOR/RADAR Post Hoc Analysis of the EAST Appendicitis MUSTANG Study

Background: There is no consensus on the duration of antibiotic use after appendectomy. We hypothesized that restricted antibiotic use is associated with better clinical outcomes. Patients and Methods: We performed a post hoc analysis of the Eastern Association for the Surgery of Trauma (EAST) Multicenter Study of the Treatment of Appendicitis in America-Acute, Perforated, and Gangrenous (MUSTANG) study using the desirability of outcome ranking/response adjusted for duration of antibiotic risk (DOOR/RADAR) framework. Three separate datasets were analyzed based on restricted versus liberal post-operative antibiotic groups: simple appendicitis (no vs. yes); complicated appendicitis, only four days (≤24 hours vs. 4 days); and complicated appendicitis, four or more days (≤24 hours vs. ≥4 days). Patients were assigned to one of seven mutually exclusive DOOR categories RADAR ranked within each category. DOOR/RADAR score pairwise comparisons were performed between all patients. Each patient was assigned either 1, 0, or -1 if they had better, same, or worse outcomes than the other patient in the pair, respectively. The sum of these numbers (cumulative comparison score) was calculated for each patient and the group medians of individual sums were compared by Wilcoxon rank sum. Results: For simple appendicitis, the restricted group had higher median sums than the liberal group (552 [552,552] vs. -1,353 [-1,353, -1,353], p < 0.001). For both complicated appendicitis analyses, the restricted group had higher median sums than the liberal: only 4 (196 [23,196] vs. -121 [-121, -121], p < 0.02) and 4 or more (660 [484,660] vs -169 [-444,181], p < 0.001). Conclusions: Restricted post-operative antibiotic use in patients after appendectomy is a dominant strategy when considering treatment effectiveness and antibiotic exposure.

CT based Acute Appendicitis Severity Index for acute appendicitis and validate its effectiveness in predicting complicated appendicitis

AIM

To propose a CT-based scoring system called Acute Appendicitis Severity Index (AASI) for diagnosis of acute appendicitis and validates its effectiveness in predicting complicated appendicitis.

SUBJECTS AND METHODS

Retrospective analyses of CT images of 120 adult patients with pathologically proven uncomplicated (n = 64) and complicated (n = 56) acute appendicitis were performed. All patients had undergone a CT scan of the abdomen and pelvis using 320 multi-detectors computed tomography with Adaptive Iterative Dose Reduction 3D (AIDR 3D). CT image parameters were identified and used to develop a CT-based scoring system (AASI) to predict the severity of acute appendicitis and its outcome. All image analysis was performed by 2 radiologists and the total score was assigned to each patient based on the proposed CT scoring system. Validation of the effectiveness of the proposed scoring system (AASI) was done using statistical models.

RESULTS

The mean and standard deviation of AASI was found to be significantly higher (P value = 0.001) in the complicated appendicitis group (observer 1 = 10.2 ± 1.6 and observer 2 = 9.63 ± 2.3) as compared to that in uncomplicated acute appendicitis group (observer 1 = 7.09 ± 2.2 and observer 2 = 6.38 ± 1.9). There was an excellent interobserver agreement of the Acute Appendicitis Severity Index for both the uncomplicated and complicated appendicitis groups (K = 0.89, 95% CI = 0.87-0.92, P = 0.001). The cutoff value for AASI used to predict complicated appendicitis was taken as 9.5 and 8.5. This resulted in an AUC of 0.877 and 0.848, accuracy of 83% and 81%, the sensitivity of 75% and 80%, the specificity of 90% and 81%, the positive predictive value of 87% and 78%, and a negative predictive value of 81% and 83% by both reviewers respectively.

CONCLUSION

The proposed CT-based AASI is a reliable parameter for the prediction of complicated appendicitis.