Appendicitis—the balance between cost effectiveness and safety remains challenging

Circulating fibrocyte percentage and neutrophil-lymphocyte ratio are accurate biomarkers of uncomplicated and complicated appendicitis: a prospective cohort study

BACKGROUND

There is increasing evidence that uncomplicated appendicitis (UA) may be treated nonoperatively in cases of UA. This study aimed to evaluate and compare the diagnostic accuracy of circulating fibrocyte percentage (CFP), white blood cell count, C-reactive protein, and neutrophil-lymphocyte ratio (NLR) in diagnosing uncomplicated and complicated appendicitis.

MATERIALS AND METHODS

Eighty consecutive adult patients presenting with suspected appendicitis were recruited in a cohort-based prospective study between June 2015 and February 2016 at University Hospital Limerick in Ireland. Peripheral venous samples were obtained at the presentation. Clinical, biochemical, radiological, and histopathological parameters were recorded. The CFP was determined by dual-staining for CD45 and collagen-I using flow cytometry analysis and correlated with histopathological diagnoses.

RESULTS

Of the 46 patients who underwent appendicectomy, 34 (73.9%) had histologically proven acute appendicitis. A comparison of the diagnostic accuracy of biomarkers demonstrated the CFP had the highest diagnostic accuracy for UA (area under the curve=0.83, sensitivity=72.7%, specificity=83.3%, P=0.002). The NLR had the highest diagnostic accuracy in relation to complicated appendicitis (area under the curve=0.84, sensitivity=75.5%, specificity=83.3%, P=0.005).

CONCLUSIONS

CFP and NLR are accurate biomarkers of UA and complicated appendicitis.

Diagnostic accuracy of computed tomography and ultrasound for the diagnosis of acute appendicitis: A systematic review and meta-analysis

INTRODUCTION

The diagnosis of acute appendicitis remains challenging. This review determined the current diagnostic accuracy of CT and ultrasound for suspected acute appendicitis in adults.

METHODS

This systematic review adhered to the PRISMA for diagnostic test accuracy guidelines. A systematic search was undertaken in appropriate databases. Screening of potential titles and abstracts, full-text retrieval, methodological quality assessment using QUADAS, and data extraction was performed. Meta-analyses were performed for relevant subgroups, and sensitivity analysis was completed to account for outliers. GRADE was utilized to assess the certainty of findings.

RESULTS

31 studies evaluating CT, 10 evaluating US, and six evaluating both were included. Pooled sensitivity and specificity for CT was 0.972 [0.958, 0.981] and 0.956 [0.941, 0.967] respectively, and 0.821 [0.738, 0.882] and 0.859 [0.727, 0.933] for US, respectively. When analyzing subgroups based on the use of contrast enhancement, sensitivity and specificity was highest for CT with intravenous and oral contrast (0.992 [0.965, 0.998], 0.974 [0.936, 0.99]), compared to CT with intravenous contrast (0.955 [0.922, 0.974], 0.942 [0.916, 0.960]). Low-Dose CT produced comparable values (0.934 [0.885,0.963], 0.937 [0.911, 0.955]) relative to these subgroups and standard dose non-contrast CT (0.877 [0.774,0.937], 0.914 [0.827, 0.959]). US studies which excluded equivocal findings demonstrated significantly greater values than the remainder of US studies (p < 0.0001).

CONCLUSION

The updated diagnostic test accuracies of CT, US and relevant subgroups should be implemented in light of factors such as dose, cost, and timing.

IMPLICATIONS FOR PRACTICE

For diagnosis of adult acute appendicitis: • CT with intravenous plus oral contrast enhancement yields statistically significantly greater diagnostic accuracy than CT with intravenous contrast alone. • Low-dose CT yields comparable sensitivity and specificity to standard-dose CT. • Ultrasound studies which exclude equivocal results may overinflate sensitivity and specificity.

The Dynamics of Inflammatory Markers in Patients with Suspected Acute Appendicitis

Background: Laboratory tests of inflammatory mediators are routinely used in the diagnosis of acute appendicitis (AA). The aim of this study was to evaluate the differences of dynamics of inflammatory markers of the blood in patients with suspected acute appendicitis between complicated AA (CAA), non-complicated AA (NAA), and when AA was excluded (No-AA). Methods: This was a retrospective analysis of prospectively collected data of patients presented to the Emergency Department (ER) of a tertiary hospital center during a three-year period. All patients suspected of acute appendicitis were prospectively registered from 1 January 2016 to 31 December 2018. The dynamics of inflammatory markers of the blood between different types of AA (No-AA, NAA or CAA) during different periods of time are presented. Results: A total of 453 patients were included in the study, with 297 patients in the No-AA group, 99 in the NAA group, and 57 in the CAA group. White blood cell (WBC) count in the No-AA decreased with time, with a statistically significant difference between the <8 h and 25–72 h group. The neutrophils (NEU) percentage decreased in the No-AA group and was statistically significantly different between the <8 h and 25–72 h and <8 h and >72 h groups. C-reactive protein (CRP) increased significantly in the No-AA group throughout all time intervals, and from the first 24 h to the 25–72 h in the NAA and CAA groups. There was a statistically significant difference between the WBC count between No-AA, NAA, and No-AA and CAA groups during the first 24 and 24–48 h. There was a statistically significant difference between NEU percentage and LYMP percentage and in the NEU/LYMP ratio between No-AA and CAA groups through all time periods. CRP was significantly higher in the first 24 h in the CAA than in the No-AA group, and in the 24–48 h in the CAA group than in the No-AA and NAA groups. The linear logistic regression model, involving inflammatory mediators and clinical characteristics, showed mediocre diagnostic accuracy for diagnosing AA with an AUC of 0.737 (0.671–0.802). Conclusions: Increasing concentrations of inflammatory markers are more characteristic in CAA patients than in No-AA during the first 48 h after onset of the disease. A combination of laboratory tests with clinical signs and symptoms has a mediocre diagnostic accuracy in suspecting AA.

DIALAPP: a prospective validation of a new diagnostic algorithm for acute appendicitis

Purpose

The management of patients with suspected appendicitis remains a challenge in daily clinical practice, and the optimal management algorithm is still being debated. Negative appendectomy rates (NAR) continue to range between 10 and 15%. This prospective study evaluated the accuracy of a diagnostic pathway in acute appendicitis using clinical risk stratification (Alvarado score), routine ultrasonography, gynecology consult for females, and selected CT after clinical reassessment.

Methods

Patients presenting with suspected appendicitis between November 2015 and September 2017 from age 18 years and above were included. Decision-making followed a clear management pathway. Patients were followed up for 6 months after discharge. The hypothesis was that the algorithm can reduce the NAR to a value of under 10%.

Results

A total of 183 patients were included. In 65 of 69 appendectomies, acute appendicitis was confirmed by histopathology, corresponding to a NAR of 5.8%. Notably, all 4 NAR appendectomies had other pathologies of the appendix. The perforation rate was 24.6%. Only 36 patients (19.7%) received a CT scan. The follow-up rate after 30 days achieved 69%, including no patients with missed appendicitis. The sensitivity and specificity of the diagnostic pathway was 100% and 96.6%, respectively. The potential saving in costs can be as much as 19.8 million €/100,000 cases presenting with the suspicion of appendicitis.

Conclusion

The risk-stratified diagnostic algorithm yields a high diagnostic accuracy for patients with suspicion of appendicitis. Its implementation can safely reduce the NAR, simultaneously minimizing the use of CT scans and optimizing healthcare-related costs in the treatment of acute appendicitis.

Trial registration

ClinicalTrials.gov Identifier: NCT02627781 (December 2015)

Cost-effectiveness analysis of initial nonoperative management versus emergency laparoscopic appendectomy for acute complicated appendicitis

Background

The evidence regarding the safety and efficacy of nonoperative management is growing. However, the best treatment strategy for acute complicated appendicitis remains controversial. We aimed to evaluate the cost-effectiveness of treatment strategies for complicated appendicitis patients. This study sought to determine the most cost-effective strategy from the health care-payer’s perspective.

Methods

The primary outcome was an incremental cost effectiveness ratio (ICER) using nonoperative management with or without interval laparoscopic appendectomy (ILA) as the intervention compared with operative management with emergency laparoscopic appendectomy (ELA) alone as the control. Model variables were abstracted from a literature review, and from data obtained from the hospital records of Tochigi Medical Center. Cost-effectiveness was evaluated using an ICER. We constructed a Markov model to compare treatment strategies for complicated appendicitis in otherwise-healthy adults, over a time horizon of a single year. Uncertainty surrounding model parameters was assessed via one-way- and probabilistic-sensitivity analyses. Threshold analysis was performed using the willingness-to-pay threshold set at the World Health Organization’s criterion of $107,690.

Results

Three meta-analysis were included in our analysis. Operative management cost $6075 per patient. Nonoperative management with interval laparoscopic appendectomy (ILA) cost $984 more than operative management and produced only 0.005 more QALYs, resulting in an ICER of $182,587. Nonoperative management without ILA cost $235 more than operative management, and also yielded only 0.005 additional QALYs resulting in an ICER of $45,123 per QALY. Probabilistic sensitivity analysis with 1000 draws resulted in average ICER of $172,992 in nonoperative management with ILA and $462,843 in Nonoperative management without ILA. The threshold analysis demonstrated that regardless of willingness-to-pay, nonoperative management without ILA would not be most cost-effective strategy.

Conclusions

Nonoperative management with ILA and Nonoperative management without ILA were not cost-effective strategies compared with operative management to treat complicated appendicitis. Based on our findings, operative management remains the standard of care and nonoperative management would be reconsidered as a treatment option in complicated appendicitis from economic perspective.

Role of circulating fibrocytes in the diagnosis of acute appendicitis

Background

Improved diagnostic biomarkers are required for acute appendicitis. The circulating fibrocyte percentage (CFP) is increased in inflammatory states, but has not been studied in acute appendicitis. This study aimed to determine CFP in acute appendicitis and compare diagnostic accuracy with standard serological biomarkers.

Methods

A prospective cohort study was carried out between June 2015 and February 2016 at University Hospital Limerick. The CFP was determined by dual‐staining peripheral venous samples for CD45 and collagen I using fluorescence‐activated cell sorting, and correlated with histopathological diagnoses. The accuracy of CFP in determining histological acute appendicitis was characterized and compared with the white cell count, C‐reactive protein concentration, neutrophil count, lymphocyte count and neutrophil : lymphocyte ratio.

Results

Of 95 adults recruited, 15 were healthy individuals and 80 had suspected appendicitis at presentation. Forty‐six of these 80 patients had an appendicectomy, of whom 34 had histologically confirmed appendicitis. The CFP was statistically higher in patients with pathologically proven acute appendicitis than in healthy controls (median 6·1 (i.q.r. 1·6–11·6) versus 2·3 (0·9–3·4) per cent respectively; P = 0·008). The diagnostic accuracy of CFP, as determined using the area under the receiver operating characteristic (ROC) curve, was similar to that of standard biomarkers. In multinomial regression analysis, only raised CFP was retained as an independent prognostic determinant of acute appendicitis (odds ratio 1·57, 95 per cent c.i. 1·05 to 2·33; P = 0·027).

Conclusion

The CFP is increased in histologically confirmed acute appendicitis and is as accurate as standard serological biomarkers in terms of diagnosis.

Does CT Reduce the Rate of Negative Laparoscopies for Acute Appendicitis? A Single-Center Retrospective Study

In surgical practice, surgeons request CT scans to rule out acute appendicitis, even in young patients. We aimed to assess the feasibility of using a CT scan to reduce the rate of negative laparoscopies in patients younger than 40 with equivocal signs of acute appendicitis. Therefore, we conducted a retrospective observational study on the patients admitted with a provisional diagnosis of acute appendicitis. Patients younger than 40 and with the Alvarado score between 3 and 6 were included. These were divided into two groups: those who had or did not have a CT scan. Each group was further subdivided into patients that had a laparoscopy and those that did not. Out of 204 patients included in the study, 16% were included in the CT group, and 84% in the non-CT group. 71.9% of the patients that underwent a CT scan had appendicitis and underwent an appendectomy. Five patients with a normal CT scan had appendectomy due to persistent signs of acute appendicitis. The histopathology of the 23 patients with positive CT was positive, and 3 of the 5 patients with negative CT that underwent appendectomy had positive histology results. The negative appendectomy rate for patients that had preoperative CT is 7.14% compared to 32.4% in patients without preoperative CT. The rate of negative laparoscopy in patients younger than 40 years old that undergo preoperative CT is significantly lower with a p-value of .00667.

Reducing the negative appendectomy rate with the laparoscopic appendicitis score; a multicenter prospective cohort and validation study

BACKGROUND

Approximately nine percent of all acute appendectomies are unintentionally performed on a normal appendix. Failure of treatment (negative appendectomy or missed appendicitis) is associated with higher morbidity and mortality when compared to appendectomy for uncomplicated appendicitis. The Laparoscopic APPendicitis (LAPP) score was developed in order to systematically evaluate the appendix for the presence of inflammation. This study aims to determine whether the LAPP score reduces the negative appendectomy rate without missing appendicitis.

METHODS

From September 2013 through May 2016, 322 adult patients presenting with a clinical suspicion of acute appendicitis and an indication for diagnostic laparoscopy were included and analyzed in this multicenter prospective validation study. Depending on the LAPP score, the appendix was either removed (n = 300) or left in situ (n = 22). These patients were compared to a historical control group of 584 patients treated at the same hospitals. The appendix was examined by a pathologist and the negative appendectomy rate was calculated.

RESULTS

The negative appendectomy rate was significantly lower when the LAPP score was used (4,7% vs. 8,4%; P = 0,034). None of the patients with a negative LAPP score, in which the appendix remained in situ, developed acute appendicitis within three months. There were no significant differences in operation time, complications, or readmissions. Using the LAPP score was associated with significantly higher rates of preoperative radiological imaging (98% vs. 70%; P < 0,001). After adjusting for covariables, including radiological imaging, use of the LAPP score led to fewer treatment failures when compared to not using the LAPP score (OR: 0,48, 95% C.I. 0,251 to 0,914; P = 0,025).

CONCLUSION

The LAPP score is a safe and simple tool to reduce the negative appendectomy rate during laparoscopic surgery without missing cases of acute appendicitis.

The Accuracy of Low-dose Computed Tomography Protocol in Patients With Suspected Acute Appendicitis: The OPTICAP Study

OBJECTIVE

To compare diagnostic accuracy of contrast enhanced low-dose computed tomography (CT) accomplished in the OPTICAP trial phantom phase to standard CT in patients with suspected acute appendicitis.

BACKGROUND

Increasing use of CT as the gold standard in diagnosing acute appendicitis has raised concerns regarding radiation exposure. Unenhanced low-dose CT protocols have shown similar diagnostic accuracy with standard CT for diagnosing appendicitis. To our knowledge, there are no other trials in which the same patient with suspected acute appendicitis underwent both standard and low-dose CT allowing interpatient comparison.

METHODS

OPTICAP is an interpatient protocol sequence randomized noninferiority single-center trial performed at Turku University Hospital between November, 2015 and August, 2016. Sixty patients with suspected acute appendicitis and body mass index <30 kg/m were enrolled to undergo both standard and low-dose contrast enhanced CT scans, which were categorized as normal, uncomplicated or complicated appendicitis by 2 radiologists in blinded manner. All patients with CT confirmed appendicitis underwent appendectomy to obtain histopathology.

RESULTS

The low-dose protocol was not inferior to standard protocol in terms of diagnostic accuracy; 79% [95% confidence interval (CI) 66%-89%) accurate diagnosis in low-dose and 80% (95% CI 67%-90%) in standard CT by primary radiologist. Accuracy to categorize appendicitis severity was 79% for both protocols. The mean radiation dose of low-dose CT was significantly lower compared with standard CT (3.33 and 4.44 mSv, respectively).

CONCLUSION

Diagnostic accuracy of contrast enhanced low-dose CT was not inferior to standard CT in diagnosing acute appendicitis or distinguishing between uncomplicated and complicated acute appendicitis in patients with a high likelihood of acute appendicitis. Low-dose CT enabled significant radiation dose reduction.

LOW-DOSE CT PROTOCOL OPTIMIZATION FOR THE ASSESSMENT OF ACUTE APPENDICITIS: THE OPTICAP PHANTOM STUDY

The aim was to evaluate effects of voltage, noise input (NI) and iterative reconstruction (IR) on radiation dose and image quality in order to establish a contrast enhanced low-dose protocol for assessment of acute appendicitis. An anthropomorphic abdominal phantom mimicking contrast enhanced abdomen was scanned with 80, 100 and 120 kV, standard and strong IR and 11 NIs (66 protocols). A total of 14 test tubes of increasing iodine dilutions and one tube with an appendicolith were evaluated within the phantom. The dose, HUs, noise, contrast-to-noise ratio (CNR) and figure of merit (FOM) were determined. Visual quality scores were assessed by two readers. A clinically used voltage-IR combination (120 kV, standard IR) was used as a reference. Overall, 100 kV with standard IR (p = 0.002) and 80 kV with both IRs (p < 0.001) showed higher CNR than the reference, but noise was most pronounced at 80 kV (p < 0.001). The highest FOM was found in the 100 kV protocols (p < 0.001). The reference and 100 kV with standard IR had highest image quality scores, where the 100 kV protocol enabled a distinct dose reduction. Lowering the voltage seems to be a more favorable tool than IR changes in optimizing the dose in contrast enhanced abdominal CT.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT01022567.