A scoring system to predict the severity of appendicitis in children

Accuracy Evaluation of Pediatric Appendicitis Scoring (PAS) Method in Differentiating Nonspecific Abdominal Pain from Appendicitis

Background

This study aimed at evaluating the accuracy of the pediatric appendicitis scoring method in differentiating nonspecific abdominal pain (NSAP) from appendicitis.

Methods

This cross-sectional study was conducted on 391 children who were hospitalized in the emergency ward due to acute abdominal pain suspected of appendicitis . Pediatric Appendicitis Score (PAS), C-reactive protein (CRP), and appendicitis pathology results of patients undergoing surgery were recorded.

Results

The results showed that the no significant difference was found among patients in the three experimental groups (appendicitis, specific abdominal pain except appendicitis, and NSAP) with respect to temperature (p = 0.212), but the other variables were significantly different. Findings showed that high CRP frequency, pain migration to right lower quadrant (RLQ), tenderness in right iliac fossa (RIF), anorexia, leukocytosis, high neutrophil, and mean tenderness in RLQ in the appendicitis group were higher than those in the other two groups (p = 0.001). The PAS questionnaire can also be used as a reliable questionnaire with appropriate sensitivity (0.929) and specificity (0.993), and this questionnaire along with detailed clinical examinations could reduce the rate of negative appendectomy to less than 1%.

Conclusions

This study showed high accuracy of PAS in diagnosing children with appendicitis and differentiating appendicitis from cases of NSAP and specific abdominal pain other than appendicitis. The PAS system could also significantly reduce cases of negative appendicitis. Although high CRP had an excellent ability to diagnose appendicitis, its accuracy was lower than PAS.

The development and application of pediatric complicated appendicitis prediction model

BACKGROUND

Acute appendicitis in children refers to the acute inflammation of the appendix, which accounts for 20% ∼ 30% of cases of acute abdomen in pediatric surgery.

OBJECTIVE

This study aimed to establish a decision tree model of complicated appendicitis in children using appendiceal ultrasound combined with an inflammatory index and evaluated its clinical efficacy in pediatric patients.

METHODS

A total of 395 children admitted to the Emergency Department of the Shanghai Children's Hospital from January 2018 to December 2021 and diagnosed with appendicitis by postoperative pathology were retrospectively analyzed. According to the postoperative pathology, the children were divided into a complicated and non-complicated appendicitis group, respectively. Routine laboratory inflammatory indicators, including white blood cell count, N(%), neutrophil (Neu) count, Neu/lymphocyte ratio (NLR), C-reactive protein (CRP), and procalcitonin were collected from the two groups. Collecting data on ultrasound examination of the appendix includes whether the appendix diameter is thickened, whether the echogenicity of the mesenteric rim surrounding the appendix is enhanced, whether there is rich blood supply in the appendix, and whether there are fecaliths in the appendix lumen. The risk factors for complicated appendicitis were screened out by univariate and multivariate logistic regression analyses, the binary logistic regression prediction and decision tree models were established, respectively, and the receiver operating characteristic (ROC) curve was used to verify the accuracy of the two prediction models.

RESULTS

Binary logistic regression analysis showed that CRP, NLR, the presence of an appendicolith, and peripheral retina echo enhancement were independent risk factors for complicated appendicitis in children (P< 0.05). The decision tree model had an overall accuracy of 79%, an area under the ROC curve (AUC) of 0.809 (95% confidence interval [CI] 0.780-0.865), and sensitivity and specificity of 71.3% and 77.7%, respectively. The logistic regression model had an overall accuracy of 74.9%, an AUC value of 0.823 (95% CI, 0.765-0.853), a sensitivity value of 80.3%, and a specificity of 71.8%.

CONCLUSION

This predictive model, based on ultrasound of the appendix combined with inflammatory markers, provides a useful method to assist pediatric emergency physicians in diagnosing childhood appendicitis. The decision tree model reflected the interaction of various indexes, and the model was simple, intuitive, and effective.

Association of Gangrenous, Suppurative, and Exudative Findings With Outcomes and Resource Utilization in Children With Nonperforated Appendicitis

Importance

The clinical significance of gangrenous, suppurative, or exudative (GSE) findings is poorly characterized in children with nonperforated appendicitis.

Objective

To evaluate whether GSE findings in children with nonperforated appendicitis are associated with increased risk of surgical site infections and resource utilization.

Design, Setting, and Participants

This multicenter cohort study used data from the Appendectomy Targeted Database of the American College of Surgeons Pediatric National Surgical Quality Improvement Program, which were augmented with operative report data obtained by supplemental medical record review. Data were obtained from 15 hospitals participating in the Eastern Pediatric Surgery Network (EPSN) research consortium. The study cohort comprised children (aged ≤18 years) with nonperforated appendicitis who underwent appendectomy from July 1, 2015, to June 30, 2020.

Exposures

The presence of GSE findings was established through standardized, keyword-based audits of operative reports by EPSN surgeons. Interrater agreement for the presence or absence of GSE findings was evaluated in a random sample of 900 operative reports.

Main Outcomes and Measures

The primary outcome was 30-day postoperative surgical site infections (incisional and organ space infections). Secondary outcomes included rates of hospital revisits, postoperative abdominal imaging, and postoperative length of stay. Multivariable mixed-effects regression was used to adjust measures of association for patient characteristics and clustering within hospitals.

Results

Among 6133 children with nonperforated appendicitis, 867 (14.1%) had GSE findings identified from operative report review (hospital range, 4.2%-30.2%; P < .001). Reviewers agreed on presence or absence of GSE findings in 93.3% of cases (weighted κ, 0.89; 95% CI, 0.86-0.92). In multivariable analysis, GSE findings were associated with increased odds of any surgical site infection (4.3% vs 2.2%; odds ratio [OR], 1.91; 95% CI, 1.35-2.71; P < .001), organ space infection (2.8% vs 1.1%; OR, 2.18; 95% CI, 1.30-3.67; P = .003), postoperative imaging (5.8% vs 3.7%; OR, 1.70; 95% CI, 1.23-2.36; P = .002), and prolonged mean postoperative length of stay (1.6 vs 0.9 days; rate ratio, 1.43; 95% CI, 1.32-1.54; P < .001).

Conclusions and Relevance

In children with nonperforated appendicitis, findings of gangrene, suppuration, or exudate are associated with increased surgical site infections and resource utilization. Further investigation is needed to establish the role and duration of postoperative antibiotics and inpatient management to optimize outcomes in this cohort of children.

Identification of the optimal treatment strategy for complex appendicitis in the paediatric population: a protocol for a multicentre prospective cohort study (CAPP study)

INTRODUCTION

In daily practice large heterogeneity in the treatment of children with complex appendicitis exists. Complex appendicitis can be divided into two subtypes; complex appendicitis with and without appendiceal mass and/or abscess. As complex appendicitis is associated with high morbidity and costs, identification of the optimal treatment strategy is essential. In this article, we present the study protocol for the CAPP (Complex Appendicitis in the Pediatric Population) study.

METHODS AND ANALYSIS

This nation-wide, multi-centre, comparative, non-randomised prospective cohort study includes all children <18 years old with a preoperative suspicion of complex appendicitis, which is based on imaging confirmed acute appendicitis and predefined criteria regarding the severity of appendicitis. Eligible patients are recruited in more than 30 hospitals. Open appendectomy will be compared with laparoscopic appendectomy for children without appendiceal mass and/or abscess and initial non-operative treatment (ie, intravenous antibiotics with or without percutaneous drainage) to direct appendectomy for children with appendiceal mass and/or abscess. Based on historical data supplied by the participating hospitals and an inclusion period of 2 years and 9 months, a sample size of 1308 patients is aimed. Primary outcome is the proportion of patients experiencing any complication at 3 months follow-up. Reported complications will be assessed by an independent adjudication committee. Secondary outcomes include, but are not limited to, quality of life, and (in)direct costs. To adjust for baseline differences and selection bias, outcomes will be compared after propensity score analysis (inverse probability weighting and stratification).

ETHICS AND DISSEMINATION

The Medical Ethics Review Committee of the Amsterdam UMC, location AMC, declared that the Medical Research involving Human Subjects Act (WMO) did not apply to this study. Therefore, no official approval was required by national law. Study results will be presented in peer-reviewed scientific journals and at (inter)national conferences.

TRIAL REGISTRATION NUMBERS

NCT04755179; NL9371.

Predictive scoring systems to differentiate between simple and complex appendicitis in children (PRE-APP study)

BACKGROUND

Several clinical prediction rules have been developed for preoperative differentiation between simple and complex appendicitis in children, as potential treatment strategies differ. This study aimed to externally validate applicable clinical prediction rules that could be used to differentiate between simple and complex appendicitis in children.

METHODS

Potential clinical prediction rules were identified by a scoping review of the literature. Clinical prediction rules applicable in our daily practice were subsequently externally validated in a multicenter historical cohort consisting of 1 tertiary center and 1 large teaching hospital. All children (<18 years old) with histopathologically confirmed acute appendicitis between 2013 and 2020 were included. Test results of clinical prediction rules were compared to the gold standard of either simple or complex appendicitis consisting of predefined perioperative and histopathological criteria. Areas under the receiver operating characteristic curves were determined for the selected clinical prediction rules. Areas under the receiver operating characteristic curve >0.7 were considered acceptable and potentially useful.

RESULTS

In total, 31 clinical prediction rules were identified, of which 12 could be evaluated in our cohort consisting of 550 children. The main reason to exclude clinical prediction rules was the use of variables that were not routinely measured in our cohort. In our cohort, 208/550 (38%) were diagnosed with complex appendicitis according to the gold standard. Clinical prediction rules with areas under the receiver operating characteristic curve >0.7 were: Gorter (0.81), Bogaard (0.79), Bröker (0.79), Graham (0.77), Hansson (0.76), BADCF (0.76), and Eddama (0.75).

CONCLUSION

In this study, clinical prediction rules consisting of a combination of clinical and objective variables had the highest discriminative ability. External validation showed that 7 clinical prediction rules were potentially useful. Integration of these clinical prediction rules in daily practice is proposed to guide decision making regarding treatment strategies.

The potential of rectal swabs to differentiate simple and complex appendicitis in children with a microbiota-based test

Currently, accurate biomarkers differentiating simple (phlegmonous) from complex (gangrenous and/or perforated) appendicitis in children are lacking. However, both types may potentially require different treatment strategies, and the search for diagnostic modalities remains warranted. Previously, we demonstrated a distinct microbiota (both an increased bacterial diversity and abundance) in the appendix of children with complex compared to simple appendicitis. From the same cohort of patients we have collected 35 rectal swabs under general anesthesia prior to appendectomy and microbiota analysis was performed by IS-pro, a 16S-23S rDNA-based clinical microbiota profiling technique. Using the obtained IS-profiles, we performed cluster analyses (UPGMA), comparison of diversity (Shannon Diversity Index) and intensity (abundance in relative fluorescence units) on phylum level, and comparison on species level of bacteria between simple and complex appendicitis. Regarding these analyses, we observed no clear differences between simple and complex appendicitis. However, increased similarity of the microbial composition of the appendix and rectal swab was found within children with complex compared to simple appendicitis. Furthermore, PLS-DA regression analysis provided clear visual differentiation between simple and complex appendicitis, but the diagnostic power was low (highest AUC 0.65).   Conclusion: Microbiota analysis of rectal swabs may be viable to differentiate between simple and complex appendicitis prior to surgery as a supervised classification model allowed for discrimination of both types. However, the current diagnostic power was low and further validation studies are needed to assess the value of this method. What is Known: • Simple and complex appendicitis in children may require different treatment strategies, but accurate preoperative biomarkers are lacking. • Clear differentiation can be made between both types in children based upon the microbial composition in the appendix. What is New: • Increased similarity was found between the microbial composition of the appendix and rectal swab within children with complex compared to simple appendicitis. • Using a supervised classification model rectal swabs may be viable to discriminate between simple and complex appendicitis, but the diagnostic power was low.

Agreement between histopathological and intraoperative classifications for pediatric appendicitis and its relationship with the post-operative clinical outcome

INTRODUCTION

Some studies have shown poor agreement between intraoperative and histopathological classifications for appendicitis, despite their routine use in clinical practice.

OBJECTIVE

To investigate the agreement between histopathological and intraoperative classifications for pediatric appendicitis and evaluate the predictive potential of these classifications for the post-operative outcome.

METHODS

A retrospective, longitudinal, observational single-center study, carried out with 485 patients up to15 years of age, with a confirmed diagnosis of acute appendicitis by histopathological evaluation. The histopathological results classified the appendices as uncomplicated appendicitis when there was confirmation of the diagnosis of appendicitis without necrosis or perforation and complicated appendicitis when there was extensive necrotic tissue in the outer layer of the appendix or signs of perforation. The intraoperative findings were classified as uncomplicated appendicitis when the appendix presented with hyperemia and edema or fibrinous exudate and complicated appendicitis when the appendix showed necrosis, abscess, or perforation. The kappa index determined the agreement and the prediction relationships using a generalized linear model.

RESULTS

43.9% of cases were classified as complicated appendicitis by histopathological evaluation and 49.7% by intraoperative classification. The agreement analysis between the histopathological and intraoperative classification showed a moderate agreement, with a Kappa index of 0.419 (0.337-0.501). There was an association (P < 0.05) between the intraoperative classification and the post-operative clinical outcomes (time to start feeding, fever, intraabdominal collection, length of stay, the need for antibiotic therapy changing, and need for ICU). There was no association between histopathological classification and post-operative outcomes.

CONCLUSION

The agreement between the two classifications was moderate, and the intraoperative classification was able to predict the post-operative clinical outcomes.

Accuracy of ultrasonography for differentiating between simple and complex appendicitis in children

PURPOSE

Accurate differentiation between simple and complex appendicitis is important since differences in treatment exist. This study aimed to assess the accuracy of ultrasonography in differentiating between simple and complex appendicitis.

METHODS

Data from children aged < 18 years who underwent appendectomy between the 1st of January 2013 and the 1st of January 2018 were analyzed retrospectively. Ultrasonography reports of eligible children were divided into simple (test negative) and complex appendicitis (test positive) based on predefined criteria and compared to a gold standard (a combination of predefined perioperative and histopathological criteria). Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated to measure ultrasonographic accuracy in differentiating between simple and complex appendicitis.

RESULTS

176 children were eligible for inclusion. The mean age at the time of operation was 10.1 ± SD 4.6 years. 84 (47.7%) children had simple appendicitis and 92 (52.3%) had complex appendicitis. The use of ultrasonography yielded a sensitivity: 46%, specificity: 90%, PPV: 84%, and NPV: 60%.

CONCLUSION

Ultrasonography as standalone modality is not suitable for differentiating between simple and complex appendicitis in children. To improve preoperative differentiation, other variables such as clinical signs and laboratory data are necessary in conjunction with ultrasonography findings.

Analysis of treatment success with new inclusion criteria for antibiotic therapy for uncomplicated appendicitis: A multicentre cohort study

BACKGROUND

Conservative antibiotic treatment for uncomplicated appendicitis is debated because of the unproven criteria for use and relatively high failure rate. We developed inclusion criteria to optimize antibiotic therapy use and compared the success rate to that seen in previous literature.

METHODS

Our antibiotic therapy inclusion criteria were developed based on clinical findings (symptom onset ≤48 hours and body temperature ≤38.3℃), laboratory parameters (white blood cell count ≤12000/mL) and radiologic findings (appendiceal diameter ≤12 mm and no appendicolith). Patients who met inclusion criteria were enrolled from three hospitals between 2016 and 2017. Treatment success was defined as a response to antibiotic therapy and no recurrent symptoms within 1 year. We compared our success rate with previous clinical trial success rates.

RESULTS

There were 240 patients enrolled (116 men and 124 women) with a mean age of 38.7 years. After initial antibiotic treatment, 233 patients (97.1%) responded to therapy and were discharged. There were no post-treatment complications with Clavien-Dindo grade ≥III. During the 1-year follow-up period, the treatment success rate was 88.8% (213/240) and the recurrence rate was 8.6% (20/233; 15 underwent surgery and 5 received antibiotics again). In contrast, the combined treatment success rate for six previous clinical trials was 76.5% (573/749) and the recurrence rate was 21.6% (157/727).

CONCLUSIONS

The group enrolled with the new inclusion criteria showed an improved treatment success rate compared to previous studies. These criteria will aid in determining optimal conservative treatment use in patients with uncomplicated appendicitis.

Predictive Value of Neutrophil Count for Postoperative Complications in Children after Surgery of Perforated Appendicitis

Introduction: Perforated appendicitis (PA) in children is associated with a considerable risk for postoperative complications (POCs) such as wound infection and intra-abdominal abscess.

The aim of this study was to determine the diagnostic accuracy of hematological parameters in the early POC detection in children after PA surgery.

Materials and Methods: The study enrolled 71 patients with PA divided into two groups: 14 patients with POC (POC+ group) and 57 patients without POC (POC− group). Clinical and hematological parameters were followed preoperatively, prior to the surgery (PRO) and postoperatively on day 2 (POD2) and day 4 (POD4).

Results: The POC+ group had longer duration of higher axillar temperature as well as extended intensive and inpatient care. This group also had a significantly lower absolute neutrophil count ratio between POD2 and POD4. According to the receiver operating characteristic curve analysis, relative neutrophil count on POD4 higher than 71.8% and the ratio of absolute neutrophil count between POD2 and POD4 lower than 44.5% were found to be useful for predicting POC.

Conclusion: Absolute neutrophil count ratio between POD2 and POD4 and relative neutrophil count at POD4 could be efficient in identifying children at higher risk of developing POC after PA surgery.

Blockage of C-C Chemokine Ligand 2 Alleviated the Appendicitis-Induced Injury in Rabbit Model

C-C chemokine ligand 2 (CCL2), a low-molecular-weight cytokine, is upregulated in inflammation-related diseases. However, the underlying function of CCL2 remains unknown in human appendicitis. The present study aimed to examine the role of CCL2 in appendicitis. An enzyme-linked immunosorbent assay was performed to examine the secretion of CCL2 in the peripheral blood of patients with simple and complex appendicitis, respectively. A flow cytometry assay was used to quantify the level of the CCL2 receptor, CCR2. Moreover, we constructed an appendicitis model in rabbits. Quantitative real time-polymerase chain reaction and Western blot were used to determine CCL2 and CCR2 levels in the appendicitis model. CCL2 antibodies were used to silence the endogenous activity of CCL2 in vivo. Magnetic resonance imaging and a histopathology assay were used to examine the appendicitis-induced injury in rabbits. Our results suggested that CCL2 and its main receptor CCR2 were upregulated in patients with appendicitis, particularly those with complex appendicitis (gangrenous and perforated appendicitis). Moreover, CCL2 silencing alleviated the appendicitis-induced injury in rabbits. Our findings not only illustrate the potential value of CCL2 as a biomarker in appendicitis diagnosing but also provide novel insight into appendicitis treatment.

A clinical prediction model for complicated appendicitis in children younger than five years of age

Background

No reliably specific method for complicated appendicitis has been identified in children younger than five years of age. This study aimed to analyze the independent factors for complicated appendicitis in children younger than five years of age, develop and validate a prediction model for the differentiation of simple and complicated appendicitis.

Methods

A retrospective study of 382 children younger than five years of age with acute appendicitis from January 2007 to December 2016 was conducted with assessments of demographic data, clinical symptoms and signs, and pre-operative laboratory results. According to intraoperative findings and postoperative pathological results, acute appendicitis was divided into simple and complicated appendicitis. Univariate and multivariate analyses were used to screen out the independent factors of complicated appendicitis, and develop a prediction model for complicated appendicitis. Then 156 such patients from January 2017 to December 2019 were collected as validation sample to validate the prediction model. Test performance of the prediction model was compared with the ALVARADO score and Pediatric Appendicitis Score (PAS).

Results

Of the 382 patients, 244 (63.9%) had complicated appendicitis. Age, white blood cell count, and duration of symptoms were the independent factors for complicated appendicitis in children younger than five years of age. The final predication model for complicated appendicitis included factors above. In validation sample, the prediction model exhibited a high degree of discrimination (area under the curve [AUC]: 0.830; 95% confidence interval [CI]: 0.762–0.885) corresponding to a optimal cutoff value of 0.62, and outperformed the PAS (AUC: 0.735; 95% CI: 0.658–0.802), ALVARADO score (AUC: 0.733; 95% CI: 0.657–0.801).

Conclusion

Age, white blood cell count, and duration of symptoms could be used to predict complicated appendicitis in children younger than five years of age with acute appendicitis. The prediction model is a novel but promising method that aids in the differentiation of acute simple and complicated appendicitis.

Microbiota of Children With Complex Appendicitis: Different Composition and Diversity of The Microbiota in Children With Complex Compared With Simple Appendicitis

BACKGROUND

Two types of appendicitis are hypothesized, simple and complex, with potential different treatment strategies. To improve differentiation, underlying pathogeneses need to be further unraveled.

AIM

To determine if the microbial composition in the appendix differs between children with simple and complex appendicitis.

METHODS

Two-center, prospective cohort study including 40 children (0-17 years old) undergoing appendectomy for suspected appendicitis. Appendix tissue was used for IS-pro analysis to identify bacterial species by their length of 16S-23S rDNA interspacer (IS) region. Cluster analysis, based on IS-profiles, and correspondence with type of appendicitis, using Fisher exact test, was performed. Simple and complex appendicitis were compared regarding bacterial presence, intensity and diversity, using Fisher exact test and Mann-Whitney U test, respectively.

RESULTS

Appendicitis was confirmed in 36 of 40 patients (16 simple, 20 complex). Cluster analysis identified 2 clusters, encompassing 34 patients. Distribution of simple and complex appendicitis was 12 (80%) and 3 (20%) versus 3 (16%) and 16 (84%) patients for clusters 1 and 2, respectively (P < 0.001). Complex appendicitis was on phylum level characterized by an increased intensity (Bacteroidetes P = 0.001, Firmicutes, Actinobacteria, Fusobacteria and Verrucomicrobia (FAFV) P = 0.005 and Proteobacteria P < 0.001) and diversity (Bacteroidetes P = 0.001 and Proteobacteria P = 0.016) and an increased abundance of 5 species (Alistipes finegoldii P = 0.009, Bacteroides fragilis P = 0.002, Escherichia coli P = 0.014, Parvimonas micra P = 0.022 and Sutterella spp P = 0.026).

CONCLUSIONS

The microbial composition of the appendix differs between children with simple and complex appendicitis, regarding both composition and diversity. Future research should focus on the role of these bacteria in the pathogenesis of both types and its implications for preoperative diagnostics.

Gangrenous appendicitis: No longer complicated

BACKGROUND

Appendicitis presents on a spectrum ranging from inflammation to gangrene to perforation. Studies suggest that gangrenous appendicitis has lower postoperative infection rates relative to perforated cases. We hypothesized that gangrenous appendicitis could be successfully treated as simple appendicitis, reducing length of stay (LOS) and antibiotic usage without increasing postoperative infections.

METHODS

In February 2016, we strictly defined complex appendicitis as a hole in the appendix, extraluminal fecalith, diffuse pus or a well-formed abscess. We switched gangrenous appendicitis to a simple pathway and reviewed all patients undergoing laparoscopic appendectomy for 12 months before (Group 1) and 12 months after (Group 2) the protocol change. Data collected included demographics, appendicitis classification, LOS, presence of a postoperative infection, and 30-day readmissions.

RESULTS

Patients in Group 1 and Group 2 were similar, but more cases of simple appendicitis occurred in Group 2. Average LOS for gangrenous appendicitis patients decreased from 2.5 to 1.4 days (p < 0.001) and antibiotic doses decreased from 5.2 to 1.3 (p < 0.001). Only one gangrenous appendicitis patient required readmission, and one patient in each group developed a superficial infection; there were no postoperative abscesses.

CONCLUSIONS

Gangrenous appendicitis can be safely treated as simple appendicitis without increasing postoperative infections or readmissions.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II.

Interobserver variability in the classification of appendicitis during laparoscopy

BACKGROUND

The intraoperative classification of appendicitis dictates the patient's postoperative management. Prolonged antibiotic prophylaxis is recommended for complex appendicitis (gangrenous, perforated, abscess), whereas preoperative prophylaxis suffices for simple appendicitis. Distinguishing these two conditions can be challenging. The aim of this study was to assess interobserver variability in the classification of appendicitis during laparoscopy.

METHODS

Short video recordings taken during laparoscopy for suspected appendicitis were shown to surgeons and surgical residents. They were asked to: classify the appendix as indicative of no, simple or complex appendicitis; categorize the appendix as normal, phlegmonous, gangrenous, perforated and/or abscess; and decide whether they would prescribe postoperative antibiotics. Inter-rater reliability was evaluated using Fleiss' κ score and the S* statistic.

RESULTS

Some 80 assessors participated in the study. Video recordings of 20 patients were used. Interobserver agreement was minimal for both the classification of appendicitis (κ score 0·398, 95 per cent c.i. 0·385 to 0·410) and the decision to prescribe postoperative antibiotic treatment (κ score 0·378, 0·362 to 0·393). Agreement was slightly higher when published criteria were applied (κ score 0·552, 0·537 to 0·568).

CONCLUSION

There is considerable variability in the intraoperative classification of appendicitis and the decision to prescribe postoperative antibiotic treatment.

Initial non-operative management of uncomplicated appendicitis in children: a protocol for a multicentre randomised controlled trial (APAC trial)

INTRODUCTION

Based on epidemiological, immunological and pathology data, the idea that appendicitis is not necessarily a progressive disease is gaining ground. Two types are distinguished: simple and complicated appendicitis. Non-operative treatment (NOT) of children with simple appendicitis has been investigated in several small studies. So far, it is deemed safe. However, its effectiveness and effect on quality of life (QoL) have yet to be established in an adequately powered randomised trial. In this article, we provide the study protocol for the APAC (Antibiotics versus Primary Appendectomy in Children) trial.

METHODS AND ANALYSIS

This multicentre, non-inferiority, randomised controlled trial randomises children aged 7-17 years with imaging-confirmed simple appendicitis between appendectomy and NOT. Patients are recruited in 15 hospitals. The intended sample size, based on the primary outcome, rate of complications and a non-inferiority margin of 5%, is 334 patients.NOT consists of intravenous antibiotics for 48-72 hours, daily blood tests and ultrasound follow-up. If the patient meets the predefined discharge criteria, antibiotic treatment is continued orally at home. Primary outcome is the rate of complications at 1-year follow-up. An independent adjudication committee will assess all complications and their relation to the allocated treatment. Secondary outcomes include, but are not limited to, delayed appendectomies, QoL, pain and (in)direct costs.The primary outcome will be analysed both according to the intention-to-treat principle and the per-protocol principle, and is presented with a one-sided 97.5% CI. We will use multiple logistic and linear regression for binary and continuous outcomes, respectively, to adjust for stratification factors.

ETHICS AND DISSEMINATION

The protocol has been approved by the Medical Ethics Review Committee of the Academic Medical Center, Amsterdam. Data monitoring is performed by an independent institute and a Data Safety Monitoring Board has been assigned. Results will be presented in peer-reviewed academic journals and at (international) conferences.

TRIAL REGISTRATION NUMBER

NCT02848820; NTR5977; Pre-results.

Composition of the cellular infiltrate in patients with simple and complex appendicitis

BACKGROUND

It is now well established that there are two types of appendicitis: simple (nonperforating) and complex (perforating). This study evaluates differences in the composition of the immune cellular infiltrate in children with simple and complex appendicitis.

MATERIALS AND METHODS

A total of 47 consecutive children undergoing appendectomy for acute appendicitis between January 2011 and December 2012 were included. Intraoperative criteria were used to identify patients with either simple or complex appendicitis and were confirmed histopathologically. Immune histochemical techniques were used to identify immune cell markers in the appendiceal specimens. Digital imaging analysis was performed using Image J.

RESULTS

In the specimens of patients with complex appendicitis, significantly more myeloperoxidase positive cells (neutrophils) (8.7% versus 1.2%, P < 0.001) were detected compared to patients with a simple appendicitis. In contrast, fewer CD8+ T cells (0.4% versus 1.3%, P = 0.016), CD20 + cells (2.9% versus 9.0%, P = 0.027), and CD21 + cells (0.2% versus 0.6%, P = 0.028) were present in tissue from patients with complex compared to simple appendicitis.

CONCLUSIONS

The increase in proinflammatory innate cells and decrease of adaptive cells in patients with complex appendicitis suggest potential aggravating processes in complex appendicitis. Further research into the underlying mechanisms may identify novel biomarkers to be able to differentiate simple and complex appendicitis.

Pediatric appendicitis: state of the art review

Appendicitis is a common cause of abdominal pain in children. The diagnosis and treatment of the disease have undergone major changes in the past two decades, primarily as a result of the application of an evidence-based approach. Data from several randomized controlled trials, large database studies, and meta-analyses have fundamentally affected patient care. The best diagnostic approach is a standardized clinical pathway with a scoring system and selective imaging. Non-operative management of simple appendicitis is a reasonable option in selected cases, with the caveat that data in children remain limited. A minimally invasive (laparoscopic) appendectomy is the current standard in US and European children's hospitals. This article reviews the current 'state of the art' in the evaluation and management of pediatric appendicitis.

Retrospective Multicenter Study on Risk Factors for Surgical Site Infections after Appendectomy for Acute Appendicitis

BACKGROUND

Surgical site infections (SSI) are seen in up to 5% of patients after appendectomy for acute appendicitis. SSI are associated with prolonged hospital stay and increased costs. The aim of this multicenter study was to identify factors associated with SSI after appendectomy for acute appendicitis.

METHODS

Patients who underwent appendectomy for acute appendicitis between June 2014 and January 2015 in 6 teaching hospitals in the southwest of the Netherlands were included. Patient, diagnostic, intra-operative and disease-related factors were collected from the patients' charts. Primary outcome was surgical site infection. Multivariable logistic regression was performed to identify independent risk factors for SSI.

RESULTS

Some 637 patients were included. Forty-two patients developed a SSI. In univariable analysis body temperature >38°C, CRP>65 and complex appendicitis were associated with SSI. After multivariable logistic regression with stepwise backwards elimination, complex appendicitis was significantly associated with SSI (OR 4.09; 95% CI 2.04-8.20). Appendiceal stump closure with a stapler device was inversely correlated with SSI (OR 0.40; 95% CI 0.24-0.97) Conclusions: Complex appendicitis is a risk factor for SSI and warrants close monitoring postoperatively. The use of a stapler device for appendiceal stump closure is associated with a reduced risk of SSI.

Paradigm Shifts in the Treatment of Appendicitis

Acute appendicitis is the most common cause of emergent surgery in children. Historically, surgical dogma dictated emergent appendectomy due to concern for impending perforation. Recently, however, there has been a paradigm shift in both the understanding of its pathophysiology as well as its treatment to more nonoperative management. No longer is it considered a spectrum from uncomplicated appendicitis inevitably progressing to complicated appendicitis over time. Rather, uncomplicated and complicated appendicitis are now considered two distinct pathophysiologic entities. This change requires not only educating the patients and their families but also the general practitioners who will be managing treatment expectations and caring for patients long term. In this article, we review the pathophysiology of appendicitis, including the differentiation between uncomplicated and complicated appendicitis, as well as the new treatment paradigms. [Pediatr Ann. 2016;45(7):e235-e240.].