Preoperative assessment of complicated appendicitis through stress reaction and clinical manifestations

Development of a scoring model based on objective factors to predict gangrenous/perforated appendicitis

BACKGROUND

The mortality rate of gangrenous/perforated appendicitis is higher than that of uncomplicated appendicitis. However, non-operative management of such patients is ineffective. This necessitates their careful exam at presentation to identify gangrenous/perforated appendicitis and aid surgical decision-making. Therefore, this study aimed to develop a new scoring model based on objective findings to predict gangrenous/perforated appendicitis in adults.

METHODS

We retrospectively analyzed 151 patients with acute appendicitis who underwent emergency surgery between January 2014 and June 2021. We performed univariate and multivariate analyses to identify independent objective predictors of gangrenous/perforated appendicitis, and a new scoring model was developed based on logistic regression coefficients for independent predictors. Receiver operating characteristic (ROC) curve analysis and the Hosmer-Lemeshow test were performed to assess the discrimination and calibration of the model. Finally, the scores were classified into three categories based on the probability of gangrenous/perforated appendicitis.

RESULTS

Among the 151 patients, 85 and 66 patients were diagnosed with gangrenous/perforated appendicitis and uncomplicated appendicitis, respectively. Using the multivariate analysis, C-reactive protein level, maximal outer diameter of the appendix, and presence of appendiceal fecalith were identified as independent predictors for developing gangrenous/perforated appendicitis. Our novel scoring model was developed based on three independent predictors and ranged from 0 to 3. The area under the ROC curve was 0.792 (95% confidence interval, 0.721-0.863), and the Hosmer-Lemeshow test showed a good calibration of the novel scoring model (P = 0.716). Three risk categories were classified: low, moderate, and high risk with probabilities of 30.9%, 63.8%, and 94.4%, respectively.

CONCLUSIONS

Our scoring model can objectively and reproducibly identify gangrenous/perforated appendicitis with good diagnostic accuracy and help in determining the degree of urgency and in making decisions about appendicitis management.

Development and Validation of a Clinical Prediction Model for Complicated Appendicitis in the Elderly

Background

For elderly patients with mild clinical symptoms of uncomplicated appendicitis(UA), non-surgical treatment has been shown to be feasible, whereas emergency surgical treatment is recommended in elderly patients with complicated appendicitis(CA), but it is still challenging to accurately distinguish CA and UA before treatment. This study aimed to develop a predictive model to assist clinicians to quickly determine the type of acute appendicitis.

Methods

We retrospectively studied the clinical data of elderly patients with acute appendicitis who visited the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine from January 2012 to January 2022. The patients were divided into UA group and CA group, and the general conditions, medical history, physical examination, laboratory examination and imaging examination were compared between the two groups, and SPSS 26.0 and R 4.0.2 software were used to establish CA clinic. Predict the model, and validate it internally.

Results

The clinical data of 441 elderly patients with acute appendicitis were collected, 119 patients were excluded due to incomplete clinical data or other diseases. Finally, 332 patients were included in the study and divided into UA group (n = 229) and CA group (n = 103). By analyzing the clinical data of the two groups of patients, the duration of abdominal pain [OR = 1.094, 95% CI (1.056–1.134)], peritonitis [OR = 8.486, 95% CI (2.017–35.703))] and total bilirubin [OR = 1.987, 95% CI (1.627–2.426)] were independent predictors of CA (all p < 0.01). The model's Area Under Curve(AUC) = 0.985 (95% CI, 0.975–0.994). After internal verification by Bootstrap method, the model still has high discriminative ability (AUC = 0.983), and its predicted CA curve is still in good agreement with the actual clinical CA curve.

Conclusion

We found that a clinical prediction model based on abdominal pain duration, peritonitis, and total bilirubin can help clinicians quickly and effectively identify UA or CA before treatment of acute appendicitis in the elderly, so as to make more scientific clinical decisions.

Role of Hyperbilirubinaemia as a Predictor of Complicated Appendicitis in Paediatric Population

BACKGROUND

Acute appendicitis is a common surgical emergency amongst the paediatric population. Available diagnostic tools are focussed to make a diagnosis of acute appendicitis. A definitive predictive factor for the diagnosis of complicated appendicitis is lacking. Thus, this aims to analyse hyperbilirubinaemia as a predictor of complicated appendicitis amongst the paediatric population.

MATERIALS AND METHODS

A prospective observational study was conducted in a tertiary hospital from November 2018 to October 2019. All children undergoing emergency appendectomy were included in the study. Preoperatively, patients were evaluated clinically, and routine investigations including total and direct serum bilirubin were sent. All patients were grouped as 'simple appendicitis' or 'complicated appendicitis' based on intra-operative and histological findings. Bilirubin level was compared between these groups and analysed.

RESULTS

A total of 52 children fulfilling the inclusion criteria were included. The mean age was 13.2 ± 4.2 years, and the male: female ratio was 2.1:1. Thirty-four (65.4%) had simple appendicitis and 18 (34.6%) had complicated appendicitis. Total bilirubin was 23.83 ± 5.94 mmol/L in the complicated appendicitis group and 13.15 ± 3.29 mmol/L in the simple appendicitis group. Direct bilirubin was 5.28 ± 2.22 mmol/L in complicated appendicitis and 2.62 ± 0.83 mmol/L in simple one. Both total and direct bilirubin were significantly high in the complicated group (P < 0.001) compared to the simple appendicitis group. On the Receiver operating curve (ROC), the best cutoff value for total and direct bilirubin was 21 and 5.5 mmol/L, respectively. The sensitivity and specificity of total and direct bilirubin were 72.2%, 100%, and 61.1%, and 85.3%, respectively.

CONCLUSION

It is concluded that hyperbilirubinaemia is a good predictor for paediatric complicated appendicitis.

Periappendiceal fat-stranding models for discriminating between complicated and uncomplicated acute appendicitis: a diagnostic and validation study

BACKGROUND

Recent studies have reported promising outcomes of non-operative treatment for uncomplicated appendicitis; however, the preoperative prediction of complicated appendicitis is challenging. We developed models by incorporating fat stranding (FS), which is commonly observed in perforated appendicitis.

MATERIAL AND METHODS

We reviewed the data of 402 consecutive patients with confirmed acute appendicitis from our prospective registry. Multivariate logistic regression was performed to select clinical and radiographic factors predicting complicated acute appendicitis in our model 1 (involving backward elimination) and model 2 (involving stepwise selection). We compared c statistics among scoring systems developed by Bröker et al. (in J Surg Res 176(1):79-83. https://doi.org/10.1016/j.jss.2011.09.049 , 2012), Imaoka et al. (in World J Emerg Surg 11(1):1-5, 2016), Khan et al. (in Cureus. https://doi.org/1010.7759/cureus.4765 , 2019), Kim et al. (in Ann Coloproctol 31(5):192, 2015), Kang et al. (in Medicine 98(23): e15768, 2019), Atema et al. (in Br J Surg 102(8):979-990. https://doi.org/10.1002/bjs.9835 , 2015), Avanesov et al. (in Eur Radiol 28(9):3601-3610, 2018), and Kim et al. (in Abdom Radiol 46:1-12, 2020). Finally, we examined our models by performing the integrated discrimination improvement (IDI) test.

RESULTS

Among enrolled patients, 64 (15.9%) had complicated acute appendicitis. We developed new 10-point scoring models by including the following variables: C-reactive protein, neutrophil to lymphocyte ratio, and computed tomography features of FS, ascites, and appendicolith. A cutoff score of ≥ 6 exhibited a high sensitivity of 82.8% and a specificity of 82.8% for model 1 and 81.3% and 82.3% for model 2, respectively, with c statistics of 0.878 (model 1) and 0.879 (model 2). Compared with the model developed by Bröker et al. which included C-reactive protein and the abdominal pain duration (c statistic: 0.778), the models developed by Atema et al. (c statistic: 0.826, IDI: 5.92%, P = 0.0248), H.Y Kim et al. (c statistics: 0.838, IDI: 13.82%, P = 0.0248), and our two models (IDI: 18.29%, P < 0.0001) demonstrated a significantly higher diagnostic accuracy.

CONCLUSION

Our models and the scoring systems developed by Atema et al. and Kim et al. were validated to have a high diagnostic accuracy; moreover, our models included the lowest number of variables.

Preoperatively predicting the pathological types of acute appendicitis using machine learning based on peripheral blood biomarkers and clinical features: a retrospective study

Background

This study aimed to establish machine learning models for preoperative prediction of the pathological types of acute appendicitis.

Methods

Based on histopathology, 136 patients with acute appendicitis were included and divided into three types: acute simple appendicitis (SA, n=8), acute purulent appendicitis (PA, n=104), and acute gangrenous or perforated appendicitis (GPA, n=24). Patients with SA/PA and PA/GPA were divided into training (70%) and testing (30%) sets. Statistically significant features (P<0.05) for pathology prediction were selected by univariate analysis. According to clinical and laboratory data, machine learning logistic regression (LR) models were built. Area under receiver operating characteristic curve (AUC) was used for model assessment.

Results

Nausea and vomiting, abdominal pain time, neutrophils (NE), CD4⁺ T cell, helper T cell, B lymphocyte, natural killer (NK) cell counts, and CD4⁺/CD8⁺ ratio were selected features for the SA/PA group (P<0.05). Nausea and vomiting, abdominal pain time, the highest temperature, CD8⁺ T cell, procalcitonin (PCT), and C-reactive protein (CRP) were selected features for the PA/GPA group (P<0.05). By using LR models, the blood markers can distinguish SA and PA (training AUC =0.904, testing AUC =0.910). To introduce additional clinical features, the AUC for the testing set increased to 0.926. In the PA/GPA prediction model, AUC with blood biomarkers was 0.834 for the training and 0.821 for the testing set. Combining with clinical features, the AUC for the testing set increased to 0.854.

Conclusions

Peripheral blood biomarkers can predict the pathological type of SA from PA and GPA. Introducing clinical symptoms could further improve the prediction performance.

Diagnosis of Uncomplicated and Complicated Appendicitis in Adults

Background:

Diagnostic work-up of acute appendicitis remains challenging. While some guidelines advise to use a risk stratification based on clinical parameters, others use standard imaging in all patients. As non-operative management of uncomplicated appendicitis has been identified as feasible and safe, differentiation between uncomplicated and complicated appendicitis is of paramount importance. We reviewed the literature to describe the optimal strategy for diagnosis of acute appendicitis.

Methods:

A narrative review about the diagnosis of acute appendicitis in adult patients was conducted. Both diagnostic strategies and goals were analyzed.

Results:

For diagnosing acute appendicitis, both ruling in and ruling out the disease are important. Clinical and laboratory findings individually do not suffice, but when combined in a diagnostic score, a better risk prediction can be made for having acute appendicitis. However, for accurate diagnosis imaging seems obligatory in patients suspected for acute appendicitis. Scoring systems combining clinical and imaging features may differentiate between uncomplicated and complicated appendicitis and may enable ruling out complicated appendicitis. Within conservatively treated patients with uncomplicated appendicitis, predictive factors for non-responsiveness to antibiotics and recurrence of appendicitis need to be defined in order to optimize treatment outcomes.

Conclusion:

Standard imaging increases the diagnostic power for both ruling in and ruling out acute appendicitis. Incorporating imaging features in clinical scoring models may provide better differentiation between uncomplicated and complicated appendicitis. Optimizing patient selection for antibiotic treatment of appendicitis may minimize recurrence rates, resulting in better treatment outcomes.

Platelet indices in patients with acute appendicitis: a systematic review with meta-analysis

Correlation between blood inflammatory parameters and acute appendicitis (AA) remains controversial. This meta-analysis aims to evaluate whether platelet (PLT) indices including mean platelet volume (MPV), PLT count, and platelet distribution width (PDW) are associated with AA. Pubmed, Embase, and Cochrane Library databases were searched for observational studies published from inception through April 2020 by two independent investigators. Studies reporting associations between platelet indices and AA were selected for inclusion. Standardized mean difference (SMD) and 95% confidence interval (CI) were estimated for continuous outcomes using a DerSimonian-Laird random-effects model. Of 842 records identified, 17 studies with a total of 6793 subjects met our inclusion criteria. Meta-analysis indicated that compared with those in healthy controls, significant decrease in MPV levels was observed in subjects with AA (SMD - 0.34; 95% CI - 0.56 to - 0.12; P = 0.003). Subgroup analyses represented a significant reduction of MPV levels in patients aged ≥ 30 years and non-complicated/non-perforated AA. Due to the small number of studies and patients included in each subgroup, these subgroup analyses need to be interpreted with caution. However, none of the levels of PLT (SMD - 0.13; 95% CI - 0.28-0.012; P = 0.071) or PDW (SMD 0.30; 95% CI - 0.22-0.83; P = 0.257) was seen decrease or increase in subjects with AA. This meta-analysis indicates a significant decrease in MPV levels in patients with AA, which makes MPV have the potential of serving as a biomarker for AA. The associations of other PLT indices with AA need to be further examined.

Discriminating complicated from uncomplicated appendicitis by ultrasound imaging, computed tomography or magnetic resonance imaging: systematic review and meta-analysis of diagnostic accuracy

Background

Discriminating complicated from uncomplicated appendicitis is crucial. Patients with suspected complicated appendicitis are best treated by emergency surgery, whereas those with uncomplicated appendicitis may be treated with antibiotics alone. This study aimed to obtain summary estimates of the accuracy of ultrasound imaging, CT and MRI in discriminating complicated from uncomplicated appendicitis

Methods

A systematic literature review was conducted by an electronic search in PubMed, Embase and the Cochrane Library for studies describing the diagnostic accuracy of complicated versus uncomplicated appendicitis. Studies were included if the population comprised adults, and surgery or pathology was used as a reference standard. Risk of bias and applicability were assessed with QUADAS-2. Bivariable logitnormal random-effect models were used to estimate mean sensitivity and specificity.

Results

Two studies reporting on ultrasound imaging, 11 studies on CT, one on MRI, and one on ultrasonography with conditional CT were included. Summary estimates for sensitivity and specificity in detecting complicated appendicitis could be calculated only for CT, because of lack of data for the other imaging modalities. For CT, mean sensitivity was 78 (95 per cent c.i. 64 to 88) per cent, and mean specificity was 91 (85 to 99) per cent. At a median prevalence of 25 per cent, the positive predictive value of CT for complicated appendicitis would be 74 per cent and its negative predictive value 93 per cent.

Conclusion

Ultrasound imaging, CT and MRI have limitations in discriminating between complicated and uncomplicated appendicitis. Although CT has far from perfect sensitivity, its negative predictive value for complicated appendicitis is high.

Comparison of laparoscopic and open appendectomy on wound infection and healing in complicated appendicitis

The aim of this study was to investigate the effects of laparoscopic and open surgery on the development of postoperative surgical wound infection and wound healing between complicated appendicitis patients. Patients with complicated appendicitis were divided into those underwent laparoscopic and open surgical procedures according to the surgical method. Patients were followed up with regard to development of any postoperative wound infection, and medical, radiological, and surgical treatment methods and results were recorded. A total of 363 patients who underwent appendectomy were examined, of which 103 (28.4%) had complicated appendicitis. Postoperative wound infection rate in patients who underwent open surgery was 15.9%, while it was 6.8% in the laparoscopic surgery group. There was no statistically significant difference between the two groups in terms of infection development rates (P > .05). The rate of surgical drainage use and rehospitalisation was significantly higher in the group with wound infection than in the group without wound infection. (P < .05). We suggest that in terms of wound infection and wound healing, laparoscopic surgery should be the method of choice for patients with complicated appendicitis. In order to reduce the frequency of wound infection, drains should not be kept for a long time in patients undergoing appendectomy.