Evaluating Changes in Diagnostic Accuracy of Ultrasound for Appendicitis: Does Practice Make Perfect?

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 utility of spectral Doppler evaluation of acute appendicitis

PURPOSE

The use of spectral Doppler, peak systolic velocity (PSV), and resistive index (RI) imaging criteria to improve the accuracy of acute appendicitis diagnosis is hypothesized.

METHODS

Graded compression ultrasound was performed for suspected patients. The spectral Doppler evaluation was conducted while observing the appendix. A total of 152 patients (82 males and 70 females, ages 4-63 years, mean age of 24.5 years) were examined using the spectral Doppler waveform between 2018 and 2019. RI and PSV values of patients with and without appendicitis were compared to histopathologic findings. SPSS 26 was used to analyze the data, including using descriptive statistics and measures of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

Appendicitis was confirmed in 95 patients (62.5%) and rejected in 57 patients (37.5%). For the diagnosis of appendicitis, the area under the curve (AUC) of receiver operating characteristic (ROC) for RI (0.92 with 95% confidence interval (CI): 0.88, 0.97; P = 0.001) and PSV (0.96, with 95% CI: 0.93, 1.00; P = 0.001) was calculated. The discriminatory RI ≥ 0.49 demonstrated high sensitivity (90.5%) and low specificity (86%), and the discriminatory PSV ≥ 9.6 cm/s had high specificity (94.7%) and sensitivity (94.7%) for appendicitis.

CONCLUSION

By incorporating spectral Doppler criteria into routine graded compression ultrasound, the diagnostic accuracy of acute appendicitis was increased. In comparison, high PSV and RI values of the appendix with a cut-off point of 9.6 cm/s and 0.49 differ significantly between positive and negative appendectomy patients.

Abdominal Ultrasound and Its Diagnostic Accuracy in Diagnosing Acute Appendicitis: A Meta-Analysis

Background: Acute appendicitis (AA) is a common cause of abdominal pain encountering unnecessary surgeries in emergency departments. The present meta-analysis aims to assess the accuracy of abdominal ultrasound in suspected acute appendicitis cases in terms of sensitivity, specificity, and post-test odds for positive and negative results.

Materials and Methods: An extensive and systematic search was conducted in Medline (via PubMed), Cinahl (via Ebsco), Scopus, and Web of Sciences from 2010 till the end of March 2021. Two authors analyzed studies for inclusion, collected results, and conducted analyses separately. Examination of the histopathological tissue collected during appendectomy served as a gold standard for determining the final diagnosis of appendicitis. The accuracy was determined by evaluating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio.

Results: Out of 3,193 references, a total of 18 studies were selected. Overall sensitivity of 77.2% (95% CI – 75.4–78.9%) and specificity of 60% (95% CI – 58–62%) were observed. The diagnostic odds ratio of 6.88(95% CI 1.99–23.82) was obtained.

Conclusion: Abdominal ultrasound shows significant accuracy of diagnosis in patients with suspected acute appendicitis.