Mandatory imaging in the work-up of children suspected of having appendicitis reduces the rate of unnecessary surgeries

Diagnostic Ultrasound for Acute Appendicitis: The Gold Standard

BACKGROUND

Acute appendicitis may present a diagnostic dilemma. The aim of this study was to review the accuracy of ultrasound in the diagnosis of paediatric acute appendicitis.

METHOD

Ultrasound studies performed for investigation of appendicitis during 2015-2021 were retrieved from a tertiary paediatric hospital database and reviewed. Medical records were reviewed to determine operative intervention, further imaging, and final diagnosis. Diagnostic accuracy was assessed by sensitivity, specificity, predictivity, and overall accuracy. All appendicectomy specimens underwent histopathological confirmation. This study was approved by the local Human Research Ethics Committee.

RESULTS

A total of 8555 consecutive ultrasound examinations were performed during the study period. Mean patient age was 10.8 years ( ± 3.7). Overall diagnostic accuracy was 96.1% (8221/8555) with a visualisation rate of 91.0%. Sensitivity and specificity were 96.2% (CI 95.3-97.0%) and 96.1% (CI 95.6-96.5%), respectively. When limited to positive/negative scans, sensitivity was 99.6% (CI 99.2-99.8%) and specificity 99.0% (CI 98.7-99.3%). Positive and negative predictive values were 96.9% and 99.9%, respectively. Repeat ultrasound following a non-diagnostic scan led to a definitive diagnosis in 76.1%. Negative appendicectomy rate was 5.5% overall in children who had undergone pre-operative ultrasound (107/1938), and 4.4% when other surgical pathologies were excluded.

CONCLUSION

Ultrasound examination provides gold-standard accuracy in the diagnosis of paediatric appendicitis and reduces rates of negative appendicectomy. Given the disadvantages of computed tomography and magnetic resonance imaging, ultrasound should be considered the first-line investigation of choice in the diagnosis of acute appendicitis in children.

LEVEL OF EVIDENCE

III.

The use of a score-based protocol in pediatric appendicitis decreases CT scan utilization when evaluating children in a community hospital

Background

The Pediatric Appendicitis Score (PAS) is a validated scoring system assessing children with abdominal pain. Prior to 2016, children with abdominal pain in our community hospital were evaluated primarily using CT scans. A protocol using PAS and ultrasound (US) as the primary radiologic modality was adopted in 2016 for evaluating children with abdominal pain. The protocol consisted of three tiers with low PAS requiring no radiologic evaluation; moderate PAS requiring US and high PAS requiring initial surgical consultation. Retrospective chart review of children presenting with clinically suspected appendicitis was performed from January 2015 through December 2017, representing 1 year before and 2 years after implementation of PAS protocol. PAS scoring was assigned retrospectively to patients not scored in the emergency physician’s note, and statistical analysis of the patient cohorts was performed using SPSS, version 17. This study was approved by the University of Nevada Institutional Review Board.

Results

Application of PAS scoring system increased use of US as the primary radiologic test from 59% pre-protocol to 91% post protocol and decreased use of CT scans from 41 to 8% (p < .05). Physician adherence to protocol improved from 59 to 71%, increasing further to 81% in the 2nd year post-protocol (p < .05). The highest rate of non-compliance was noted when providers ordered an US in patients with a low PAS, followed by ordering any radiologic tests in patients with a high PAS.

Conclusion

Implementation of PAS-based protocol altered clinician behavior in a community hospital when evaluating children with clinically suspected appendicitis. Improved adherence to the protocol over time with significant decrease of CT scans ordered thereby reducing radiation exposure in the pediatric population. Future improvements will be aimed at decreasing radiologic testing in patients with a low PAS and involving surgeons earlier with patients who have a high PAS as clinical acceptance to the protocol matures.

Validity of Appendicitis Inflammatory Response Score in Distinguishing Perforated from Non-Perforated Appendicitis in Children

Background: This prospective observational study aimed to evaluate the validity of appendicitis inflammatory response (AIR) score in differentiating advanced (perforated) from simple (non-perforated) appendicitis in pediatric patients. Methods: A single-center prospective cross-sectional study was conducted between 1 January 2019 until 1 May 2020 including 184 pediatric patients who underwent appendectomy. Based on the intraoperative finding of advanced (n = 38) or simple (n = 146) appendicitis the patients were divided into two groups. Recipient-operator curve (ROC), with calculation of sensitivity and specificity of best cutoff and the area under the curve (AUC), were used to measure the diagnostic value and the potential for risk stratification of the AIR score, among the patients with simple or advanced acute appendicitis. Results: The median value of the AIR score in the perforated and non-perforated groups was 10 (interquartile range, IQR 9, 11), and was 7 (IQR 6, 9), respectively (p < 0.001). Based on the calculated value of AIR score, the patients were classified with a high precision into low, indeterminate and high risk groups for acute appendicitis (p < 0.001). A cutoff value of ≥9 was demonstrated to serve as a reliable indicator of perforated appendicitis with a sensitivity and a specificity of 89.5% and 71.9%, respectively (AUC = 0.80; 95% CI: 0.719–0.871; p < 0.001). Conclusions: Acute appendicitis can be detected with a high level of sensitivity and specificity using the AIR score. Also, the AIR score may differentiate perforated from non-perforated appendicitis in pediatric patients with a high level of accuracy.

Clinical and Imaging Correlates of Pediatric Mucosal Appendicitis

BACKGROUND

Mucosal appendicitis is a controversial entity that is histologically distinct from transmural appendicitis. There is mixed opinion regarding mucosal inflammation as a spectrum of appendicitis versus a negative appendectomy. The ability to distinguish these diagnoses preoperatively is of importance to prevent unnecessary surgery. We hypothesize that patients with mucosal appendicitis can be discriminated from those with transmural disease based on specific preoperative clinical and imaging findings.

MATERIALS AND METHODS

After IRB approval, all patients who underwent laparoscopic appendectomy at our institution during 2015 were reviewed in the electronic medical record. Patients with mucosal appendicitis were identified and matched 2:1 to a random cohort of nonperforated transmural appendicitis cases. Demographic and clinical data were collected, including history, examination, laboratory, and imaging findings. Preoperative factors associated with mucosal appendicitis were modeled using binomial logistic regression analysis.

RESULTS

Of 1153 appendectomies performed during 2015, 103 patients had pathologic diagnosis of mucosal appendicitis. When compared with patients with mucosal infection, leukocytosis >10,000 per microliter led to 5.9 times higher likelihood of transmural pathology (P = 0.000). Noncompressibility on ultrasound was associated with 7.3 times higher likelihood of transmural disease (P = 0.015). Echogenic changes were predictive of transmural appendicitis, conferring 3.9 times the risk (P = 0.007). Presence of free fluid led to 2.3 times the rate of transmural pathology (P = 0.007). Finally, for every millimeter decrease in appendiceal diameter, patients were half as likely to exhibit transmural disease (P = 0.000). Together, these variables can successfully predict presence of mucosal appendicitis on final pathology report at a rate of 82.1%, and explain 60% of the variance in diagnosis of mucosal versus transmural appendicitis (P = 0.000).

CONCLUSIONS

Mucosal appendicitis remains a controversial pathologic entity, but is not associated with greater complications compared with transmural appendicitis when treated with laparoscopic appendectomy. Transmural disease can be predicted by leukocytosis, noncompressible appendix, presence of free fluid, larger appendiceal diameter and echogenicity.