The negative appendectomy rate: who benefits from preoperative CT?

Routine Computed Tomography Versus Selective Imaging: An Audit of Negative Appendicectomy Rates in Two Hospitals

Introduction There are a variety of conflicting recommendations in the literature for pre-operative imaging in acute appendicitis. There is debate over what the ideal imaging protocol is to lower the negative appendicectomy rate (NAR) without increasing missed appendicitis. The aim of this study is to compare the audited NAR between two groups with different imaging approaches: (i) mandatory pre-operative computed tomography (CT) imaging and (ii) selective imaging with CT, ultrasound (US), or no imaging prior to appendicectomy. Materials and methods A retrospective chart audit was conducted of 400 patients who underwent an appendicectomy at two hospitals with different approaches to pre-operative imaging (hospital A and hospital B). The primary outcome measure was histologically confirmed appendicitis. It was also documented whether there was radiological (CT or US) evidence of appendicitis.  Results At hospital A, all 200 patients underwent CT imaging prior to appendicectomy. The total histologically confirmed NAR for this group was 9.5% (19/200). At hospital B, 97 (48.5%) patients underwent CT, 41 (25.5%) underwent US, 10 (5%) had both US and CT, and 52 (26%) had no imaging. The total NAR was 11.5% (23/200). Conclusion There was no statistically significant difference (p=0.62) in audited NARs when comparing clinician-guided selective imaging versus routine CT imaging for all patients undergoing appendicectomy.

Identifying Recurrence Risk Factors in CT-Confirmed Acute Appendicitis in Adults Managed Non-operatively During the COVID-19 Pandemic

Background/Objective: Acute appendicitis (AA) is predominantly managed with appendectomy, but can be treated non-operatively, leading to a high risk of recurrence. Non-operative management has been more common since the COVID-19 pandemic affected the feasibility of performing surgery. This case-control study analyzed non-operatively managed patients in order to identify clinical and radiological factors associated with recurrence risk. 

Methods: Over 12 months, 48 adults with CT-proven AA managed non-operatively were identified, and followed up for at least six further months to assess them for recurrence (readmission to hospital more than 14 days after discharge and after symptom resolution, requiring treatment for appendicitis). Clinical and CT data were collected and a Cox regression survival analysis was performed to produce hazards ratios (HRs).

Results: Of the 48 patients, 12 (25%) experienced a recurrence up until the end of the follow-up period, eight of whom were then treated operatively, and four treated non-operatively. On the univariate analysis, greater recurrence risk was observed in patients with diabetes mellitus, higher heart rate (on admission and maximum value during admission), lower white cell count and neutrophils and appendiceal wall thinning on CT. On the multivariate analysis, diabetes mellitus (HR=7.72, p=0.021) and higher heart rate (HR=1.08, p=0.018) were associated with statistically significant greater recurrence risk.

Conclusions: Diabetes mellitus and higher heart rate on admission are associated with greater recurrence risk of AA managed non-operatively. No CT findings were associated with statistically significant greater risk. Clinicians should, therefore, consider DM and heart rate when making decisions on appendicitis management, especially during the COVID-19 pandemic but also beyond it.

Diagnostic accuracy of Alvarado scoring system relative to histopathological diagnosis for acute appendicitis: A retrospective cohort study

Background

Acute appendicitis (AA) is a surgical emergency that requires prompt diagnosis and suitable management. It may lead to complications resulting in mortality. To evaluate the diagnostic accuracy of the Alvarado scoring system (ASS) for acute appendicitis concerning histopathological data.

Methodology

About 120 patients were selected for this study consisting of 96 males and 24 females age between 20 and 60. Alvarado scoring system is calculated for each patient after collecting data about demographics, laboratory findings, and clinical examination. Then, we compared it with histopathological diagnosis taking it as a gold standard. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. SPSS version 20 was used for analyzing the data.

Results

About 120 patients were included in our study. The male to female ratio was 3:1. Sensitivity and specificity were 83.3% and 41% respectively. While PPV and NPV were 85% and 41% respectively. The negative appendectomy rate was 21%. The area under the curve for receiving operating characteristics is 0.628.

Conclusion

ASS is a useful diagnostic tool regarding sensitivity and positive predictive value, especially in developing countries. It is cheap, reliable, and can be easily applied.

•

We evaluated the diagnostic accuracy of the Alvarado scoring system (ASS) for acute appendicitis.

•

Sensitivity and specificity were 83.3% and 41%.

•

While PPV and NPV were 85% and 41% respectively.

Role of preoperative computed tomography in the diagnosis of acute appendicitis and reduction of negative appendectomy rates: Retrospective cross-sectional study

Background

Negative appendectomy rate (NAR) is defined as the incidence of pathologically normal appendices removed from patients suspected of having appendicitis. The objective of the present study is to determine the accuracy of CT and other modalities in diagnosing acute appendicitis, aiming to lower NAR in Saudi Arabia.

Method

Retrospective analytical study conducted across 4 hospitals in Makkah and Jeddah. A net total of 913 patients got included in the study. The data were entered and coded in excel sheet, then transformed to STATA R. software for analysis.

Results

A total of 911 patients who underwent appendectomy were included in this study; positive appendectomies were proven in (96.49%) of cases resulting in overall (3.51%) of cases of negative appendectomy when analyzing data based on age groups; adult patients who proceeded to the surgery based on clinical examination only had a NAR of (13.16% vs 2.66% who had one or more imagining studies P = 0.000).

Conclusion

Despite the fact that the diagnosis of acute appendicitis is often challenging, the patients who proceeded to the surgery based on clinical examination only had a NAR higher than those who underwent one or more imaging studies. The NAR was higher in women than men adult patients while no relation was observed in pediatric patients. Based on the present study's findings, efficient pre-operative radiological utilization is recommended in cases presented with suspicious acute appendicitis. Moreover, investing in radiological equipment and time for proper assessment can avoid the unnecessary appendectomy.

•

Highlight the importance of pre-operative imaging in reducing the negative appendectomy rate.

•

To identify the most appropriate imaging modality in detecting acute appendicitis.

Relative CT number of periappendiceal fat stranding may be an applicable index for estimating the severity of acute appendicitis

Objectives:

To investigate the feasibility of relative CT numbers to periappendiceal fat attenuation as an applicable index for estimating the severity of acute appendicitis.

Methods:

In total, 308 consecutive surgery-confirmed acute appendicitis patients and 243 controls with available preoperative CT were analyzed retrospectively. The radiological parameters were appendix diameter, length, and wall thickness as concurrent appendicitis signs. CT numbers of periappendiceal fat, mesenteric fat, subcutaneous fat in the anterior and posterior abdominal wall, retroperitoneal fat, gluteal subcutaneous fat and psoas major muscle were measured, as well as the relative CT numbers of periappendiceal fat compared with other locations.

Results:

There were 287 suppurative acute appendicitis (SAA) and 21 gangrenous or perforated acute appendicitis (GPAA) cases confirmed by pathology. The CT number of periappendiceal fat was significantly higher in patients than in controls (P＜0.01) although there was a wide overlap (−72.33 HU–117.43 HU). Significant differences in relative CT numbers were observed between the groups in gluteal subcutaneous fat (R_CTgl) and psoas major muscle (R_CTps) (P＜0.01). The AUCs of R_CTgl and R_CTps showed high accuracy to discriminate acute appendicitis from controls (AUC = 0.803, 0.761; 0.854, 0.847) and GPAA from SAA (AUC = 0.905, 0.851).

Conclusions:

Attenuation of periappendiceal fat on CT is related to the severity of appendicitis, and relative CT numbers (R_CTgl and R_CTps) could be an applicable index for severity determination.

Advances in knowledge:

Periappendiceal fat infiltration is related to the severity of acute appendicitis (especially relative CT number). Other clinical and CT features also need to be considered in the evaluation of inflammation.

The usefulness and positive predictive value of ultrasonography and computed tomography in the diagnosis of acute appendicitis in adults: a retrospective study

OBJECTIVE

To analyze the evolution of the use of imaging tests (ultrasonography and computed tomography (CT)) in the diagnosis of acute appendicitis. To determine the positive predictive value of these tests and the percentage of negative and complicated appendectomies.

MATERIAL AND METHODS

This retrospective study compared adults who underwent appendectomy for suspected acute appendicitis at our tertiary hospital during 2015 versus similar patients at our center during 2007.

RESULTS

A total of 278 patients were included. The rate of negative appendectomies descended to 5%. The positive predictive value of ultrasonography increased to 97.4% in 2015, and the positive predictive value of CT and combined CT and ultrasonography was 100%. The rate of complicated appendicitis increased (23% in 2015).

CONCLUSIONS

The use of imaging tests increased, and the rate of "blind" laparotomies decreased. Nevertheless, the rate of complicated appendicitis increased.

Suspected appendicitis pathway continues to lower CT rates in children two years after implementation

BACKGROUND

We implemented a protocol to evaluate pediatric patients with suspected appendicitis using ultrasound as the initial imaging modality. CT utilization rates and diagnostic accuracy were evaluated two years after pathway implementation.

METHODS

This was a retrospective observational study of patients <18 years evaluated for suspected appendicitis. CT rates were compared before and after implementation of the protocol, and monthly CT rates were calculated to assess trends in CT utilization.

RESULTS

CT use decreased significantly following pathway implementation from 94.2% (130/138) to 27.5% (78/284; p < 0.001). Linear regression of monthly CT utilization demonstrated that CT rates continued to trend down two years after pathway implementation. Adherence to the pathway was 89.8% (255/284). Negative appendectomy rate was 2.4% (2/85) in the post-pathway period.

CONCLUSIONS

Adherence to a pathway designed to evaluate pediatric patients with suspected appendicitis using ultrasound as the primary imaging modality has led to a sustained decrease in CT use without compromising diagnostic accuracy.

Morbidity after negative appendectomy: a single-centre experience on 627 cases

INTRODUCTION

Acute appendicitis is one of the most common causes of abdominal pain in emergency departments worldwide. Despite the improvement in radiological and clinical investigations, negative appendectomy remains a debated topic as well as the optimal strategy for use in cases demonstrating a nonpathological appendix during a procedure for suspected appendicitis. The aim of the present study was thus to analyse clinical outcomes of histologically NA to better elucidate the burden associated with a potentially avoidable procedure.

MATERIALS AND METHODS

We retrospectively analysed a prospectively collected database of all patients undergoing appendectomy for suspected appendicitis. Patients who underwent an elective appendectomy or an appendectomy for other causes than suspected appendicitis or even an appendectomy during the course of another procedure were excluded from the analysis.

RESULTS

Data of 627 patients undergoing an emergency procedure for suspected appendectomy were registered. Of the 627 patients, 533 (85%) were found to have acute appendicitis (378 uncomplicated, 155 severe), while the NA rate was 14.9%. A preoperative CT scan was performed in 148 patients (23.6%), an ultrasound evaluation was conducted in 427 patients (68.1%), and 127 patients (20.3%) underwent no imaging prior to surgical intervention. The large majority of procedures was performed laparoscopically (77.7%) and the median procedure duration was 70 min (range 17-270 min). The cumulative conversion rate (both AA and NA) was 5.7%. Leucocytes were significantly lower in cases of NA, while C-reactive protein (CRP) level was found to be increased fourfold in cases of severe versus uncomplicated appendicitis and NA. An increased use of endoloop in appendiceal stump closure was noted in the NA group (88.3% loop vs. 11.7% stapler), while endostapler usage increased in the severe appendicitis group up to 38.1%. Most patients with NA underwent only preoperative ultrasound (71.3%), with just 8.5% of patients in this group having a CT scan before surgery. Ultrasound sensivity was 0.648 and specificity was 0.438. For CT scan, sensivity was 0.949 and specificity was 0.625. LOS in the NA patient group was comparable to that of patients affected by uncomplicated appendicitis, while patients with severe appendicitis experienced a 2-day-longer median recovery. Complications were significantly higher in the severe appendicitis group but comparable in the other two groups. Surgical site infections were the most frequently reported complications.

CONCLUSIONS

Young women are particularly at risk for NA. Increasing the use of preoperative CT and incorporating imaging into the overall assessment of a patient seems to be actually the only way to reduce the incidence of NA without increasing the rates of perforation. Considering the relatively high morbidity after an NA procedure, every surgeon must carefully consider the risk-benefit balance prior to performing an appendectomy during diagnostic laparoscopy for suspected acute appendicitis showing a macroscopically noninflamed appendix.

Laparoscopic versus open surgery for suspected appendicitis

BACKGROUND

The removal of the acute appendix is one of the most frequently performed surgical procedures. Open surgery associated with therapeutic efficacy has been the treatment of choice for acute appendicitis. However, in consequence of the evolution of endoscopic surgery, the operation can also be performed with minimally invasive surgery. Due to smaller incisions, the laparoscopic approach may be associated with reduced postoperative pain, reduced wound infection rate, and shorter time until return to normal activity.This is an update of the review published in 2010.

OBJECTIVES

To compare the effects of laparoscopic appendectomy (LA) and open appendectomy (OA) with regard to benefits and harms.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE and Embase (9 February 2018). We identified proposed and ongoing studies from World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov and EU Clinical Trials Register (9 February 2018). We handsearched reference lists of identified studies and the congress proceedings of endoscopic surgical societies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing LA versus OA in adults or children.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted data. We performed the meta-analyses using Review Manager 5. We calculated the Peto odds ratio (OR) for very rare outcomes, and the mean difference (MD) for continuous outcomes (or standardised mean differences (SMD) if researchers used different scales such as quality of life) with 95% confidence intervals (CI). We used GRADE to rate the quality of the evidence.

MAIN RESULTS

We identified 85 studies involving 9765 participants. Seventy-five trials included 8520 adults and 10 trials included 1245 children. Most studies had risk of bias issues, with attrition bias being the largest source across studies due to incomplete outcome data.In adults, pain intensity on day one was reduced by 0.75 cm on a 10 cm VAS after LA (MD -0.75, 95% CI -1.04 to -0.45; 20 RCTs; 2421 participants; low-quality evidence). Wound infections were less likely after LA (Peto OR 0.42, 95% CI 0.35 to 0.51; 63 RCTs; 7612 participants; moderate-quality evidence), but the incidence of intra-abdominal abscesses was increased following LA (Peto OR 1.65, 95% CI 1.12 to 2.43; 53 RCTs; 6677 participants; moderate-quality evidence).The length of hospital stay was shortened by one day after LA (MD -0.96, 95% CI -1.23 to -0.70; 46 RCTs; 5127 participant; low-quality evidence). The time until return to normal activity occurred five days earlier after LA than after OA (MD -4.97, 95% CI -6.77 to -3.16; 17 RCTs; 1653 participants; low-quality evidence). Two studies showed better quality of life scores following LA, but used different scales, and therefore no pooled estimates were presented. One used the SF-36 questionnaire two weeks after surgery and the other used the Gastro-intestinal Quality of Life Index six weeks and six months after surgery (both low-quality evidence).In children, we found no differences in pain intensity on day one (MD -0.80, 95% CI -1.65 to 0.05; 1 RCT; 61 participants; low-quality evidence), intra-abdominal abscesses after LA (Peto OR 0.54, 95% CI 0.24 to 1.22; 9 RCTs; 1185 participants; low-quality evidence) or time until return to normal activity (MD -0.50, 95% CI -1.30 to 0.30; 1 RCT; 383 participants; moderate-quality evidence). However, wound infections were less likely after LA (Peto OR 0.25, 95% CI 0.15 to 0.42; 10 RCTs; 1245 participants; moderate-quality evidence) and the length of hospital stay was shortened by 0.8 days after LA (MD -0.81, 95% CI -1.01 to -0.62; 6 RCTs; 316 participants; low-quality evidence). Quality of life was not reported in any of the included studies.

AUTHORS' CONCLUSIONS

Except for a higher rate of intra-abdominal abscesses after LA in adults, LA showed advantages over OA in pain intensity on day one, wound infections, length of hospital stay and time until return to normal activity in adults. In contrast, LA showed advantages over OA in wound infections and length of hospital stay in children. Two studies reported better quality of life scores in adults. No study reported this outcome in children. However, the quality of evidence ranged from very low to moderate and some of the clinical effects of LA were small and of limited clinical relevance. Future studies with low risk of bias should investigate, in particular, the quality of life in children.

Negative Appendectomy Rate and Risk Factors That Influence Improper Diagnosis at King Abdulaziz University Hospital

INTRODUCTION

Acute Appendicitis is the most common emergent abdominal surgery worldwide. diagnosis based on clinical assessment, laboratory and radiological investigations and appendectomy is the treatment of choice. Removing a normal appendix is a relatively common surgical issue, defined as negative appendectomy (NA). Multiple risk factors contribute to NA; female gender, normal WBC, normal CRP count, and CT scan unavailability. However, recently NA is decreasing in incidence after CT scan and Alvarado scoring.

AIM

We aimed to estimate the rate of negative appendectomy, and determine possible risk factors among King Abdulaziz University Hospital.

PATIENTS AND METHODS

Article has a retrospective character and included non-incidental 441 patients who undergo an appendectomy, during period 2008 to 2018.

RESULTS

Negative Appendectomy incidence (9.5%) was higher among females at (64.3%). Gynecological complaints were seen in (22.2%) of cases with a sign for Negative Appendectomy. Surgery reports documented (29.6%) of female ovarian cyst diseases. Alvarado scoring at presentation was less than 7 in (69%) of cases with statistical significance value. Normal WBC count (50%), for automated neutrophil (45.2%) was high, and same number were recorded with the normal neutrophil count, all of them have statically significant relation with NA.

CONCLUSION

Proper clinical evaluation involves documenting Alvarado score, using CRP, efficient radiological utilization. Also, considering more referrals to gynecological specialists of similar presentation especially females at reproductive age. Investing in time and equipment for proper clinical assessment can avoid the unnecessary burden and save our resources for better use.

The Diagnostic Utility and Clinical Impact of After-Hours CT Scans of the Abdomen and Pelvis Investigating Abdominal Pain

Introduction

The aim of this study was to evaluate the diagnostic utility and impact on clinical management of after-hours CT scans investigating abdominal pain in surgical patients.

Methods

After-hours CT A/P reports investigating the acute surgical abdomen were compared with clinical outcomes and histopathological findings to assess sensitivity and specificity of CT reporting. Comparisons between CT reports and clinical notes were made. CT scans were categorised as having direct effects on clinical management, ruling out a serious pathology, ruling out a nonserious pathology, or having no effect. Discrepancies between information in case-notes and information provided to radiologists were also analysed.

Results

79 clinical notes were located. After-hours CT demonstrated 91% sensitivity and 82% reporting specificity using clinical outcomes as the standard. In the 26 patients with histopathological findings, CT reports demonstrated 91% sensitivity. In 79.7% of cases, CT scanning had an impact on management. In 35.4% of cases, an indication for scanning was not documented with variation in clinical information in 8.9% of cases.

Discussion

This study demonstrates after-hours CT A/P reports result in significant impacts on clinical management of surgical patients with acute abdominal pain. Improvements in providing information when requesting scans are however needed to facilitate accurate reporting.

Performance of MRI for suspected appendicitis in pediatric patients and negative appendectomy rate: A systematic review and meta-analysis

PURPOSE

To evaluate in pediatric patients the diagnostic performance of magnetic resonance imaging (MRI) for suspected appendicitis and its negative appendectomy rate.

MATERIALS AND METHODS

The study involved diagnostic accuracy studies that used MRI for pediatric patients with suspected appendicitis. Various field strengths and sequences were used in each included study. The diagnostic accuracy of MRI in pediatric patients with suspected appendicitis and negative appendectomy rate were assessed. A search of MEDLINE and EMBASE databases was performed until January 10, 2017. Two reviewers assessed the methodological quality of the articles using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Pooled sensitivity and specificity for appendicitis diagnosis were calculated using hierarchical logistic regression modeling. Meta-regression was performed to explore factors affecting study heterogeneity. The pooled negative appendectomy rate was analyzed.

RESULTS

Thirteen original articles with 1946 patients were included. The summary sensitivity and specificity were 97% (95% confidence interval [CI], 95-98%) and 97% (95% CI, 93-98%), respectively; the area under the hierarchical summary receiver operating characteristic (HSROC) curve was 0.98 (95% CI, 0.97-0.99). In meta-regression, use of diffusion-weighted imaging (P < 0.01) and age (P < 0.01) affected heterogeneity, but there was no difference according to intravenous contrast agent use (P = 0.95). The pooled negative appendectomy rate of MRI was 4.5% (95% CI, 1.9-7.1%).

CONCLUSION

MRI shows excellent diagnostic performance for appendicitis in pediatric patients regardless of the use of intravenous contrast media. Therefore, nonenhanced-only MRI protocols might be appropriate for pediatric patients with suspected appendicitis.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:767-778.

Negative Appendectomy: Clinical and Economic Implications

Historically, performing a negative appendectomy (NA) was justified to reduce the incidence of perforation. Furthermore, it is also believed that NA is associated with minimal morbidity and cost. The purpose of this study was to evaluate the frequency, clinical characteristics, and economic implications of NA. We reviewed the inpatient admissions on 274,405 patients who underwent nonincidental appendectomy as their primary procedure from the California State Inpatient Databases (2005–2011). Overall, 96.9 per cent had appendicitis (nonperforated = 73.1%, perforated = 23.8% and 3.1%) had NA. NA rates decreased steadily from 4.2 per cent in 2005 to 2.5 per cent in 2011 ( P < 0.01). The rates of appendectomy for perforated appendicitis rates also decreased slightly from 25.3 to 23.3 per cent during this time ( P = <0.01). Multivariate regression showed that female gender, African American race, and public insurance were all associated with increased NA rates. Compared with patients with appendectomy for nonperforated appendicitis, NA was associated with longer length of stay (NA = 3.2 days vs nonperforated = 1.7 days), higher median cost per admission (NA = $8626 vs nonperforated = $7605), and higher morbidity (4.7 vs 1.9%), all P < 0.01. Contrary to classic justification for NA, we did not find an inverse association of appendectomy for perforated appendicitis and NA at the hospital level. In conclusion, NA is associated with substantial clinical and financial burden, while having no apparent impact on lowering the rate of appendectomy for perforated appendicitis.

Predictive factors and outcomes of negative appendectomy

BACKGROUND

The aim of this study was to assess predictive factors for negative appendectomy and to evaluate the outcomes of negative appendectomy.

METHODS

A retrospective chart review of 4,878 patients who underwent appendectomy at our institution from January 2008 to December 2014 was performed.

RESULTS

Younger age (≤15 years), normal white blood cell count, appendix diameter of less than 6 mm on computed tomography (CT), and CT grade less than 3 were found to be independent predictive factors for negative appendectomy. When complications were investigated according to the results of pathologic diagnosis, negative appendectomy had more complications than appendectomy for nonperforated appendicitis, and this was statistically significant.

CONCLUSIONS

When CT findings are equivocal, in deciding to operate for acute appendicitis, additional ultrasonography can be performed. Furthermore, if the patient is younger than 15 years and the white blood cell count is normal, it is recommended to monitor changes in symptoms a little longer rather than operating hastily.

Risk of Gastrointestinal Cancers among Patients with Appendectomy: A Large-Scale Swedish Register-Based Cohort Study during 1970-2009

BACKGROUND

Removal of the appendix might induce physiological changes in the gastrointestinal tract, and subsequently play a role in carcinogenesis. Therefore, we conducted a nationwide register-based cohort study in Sweden to investigate whether appendectomy is associated with altered risks of gastrointestinal cancers.

METHODS

A population-based cohort study was conducted using the Swedish national registries, including 480,382 eligible patients followed during the period of 1970-2009 for the occurrence of site-specific gastrointestinal cancer (esophageal/gastric/colon/rectal cancer). Outcome and censoring information was collected by linkage to health and demography registers. We examined the incidence of appendectomy in Sweden using data from 1987-2009. We also calculated standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) to estimate the relative gastrointestinal cancer risk through comparison to the general population.

RESULTS

We noted an overall decrease in the age-standardized incidence of appendectomy among the entire Swedish population from 189.3 to 105.6 per 100,000 individuals between 1987 and 2009. Grouped by different discharge diagnosis, acute appendicitis, incidental appendectomy, and entirely negative appendectomy continuously decreased over the study period, while the perforation ratio (18%-23%) stayed relatively constant. Compared to the general population, no excess cancer risk was observed for gastrointestinal cancers under study with the exception of a marginally elevated risk for esophageal adenocarcinoma (SIR 1.32, 95% CI 1.09-1.58).

CONCLUSIONS

In Sweden, the incidence of appendectomy and acute appendicitis has decreased during 1987-2009. No excess gastrointestinal cancer risks were observed among these appendectomized patients, with the possible exception of esophageal adenocarcinoma.

Initial Performance of Radiologists and Radiology Residents in Interpreting Low-Dose (2-mSv) Appendiceal CT

OBJECTIVE

The objective of our study was to prospectively evaluate the initial diagnostic performance and learning curve of a community of radiologists and residents in interpreting 2-mSv appendiceal CT.

SUBJECTS AND METHODS

We included 46 attending radiologists and 153 radiology residents from 22 hospitals who completed an online training course of 30 2-mSv CT cases. Appendicitis was confirmed in 14 cases. Most of the readers had limited (≤ 10 cases, n = 32) or no (n = 118) prior experience with low-dose appendiceal CT. The order of cases was randomized for each reader. A multireader multicase ROC analysis was performed. Generalized estimating equations were used to model the learning curves in diagnostic performance.

RESULTS

Diagnostic performance gradually improved with years of training. The average AUC was 0.94 (95% CI, 0.90-0.98), 0.92 (0.88-0.96), 0.90 (0.85-0.96), and 0.86 (0.80-0.92) for the attending radiologists, senior residents, 2nd-year residents, and 1st-year residents, respectively. We did not observe any notable intrareader learning curves over the training course of the 30 cases except a decrease in reading time. Diagnostic accuracy and sensitivity were significantly affected by the reader training level and prior overall experience with appendiceal CT but not by the prior specific experience with low-dose appendiceal CT.

CONCLUSION

The learning curve is likely prolonged and forms gradually over years by overall radiology training and clinical experience in general rather than by experience with low-dose appendiceal CT specifically.

Histopathological correlations of appendectomies: a clinical audit of a single center

BACKGROUND

Acute appendicitis is a common presentation in surgical assessment units and appendectomy accounts for a large number of emergency operations in the UK. Histopathological examination of the appendectomy specimens are routinely carried out. The aim of this study is to correlate the histological findings of appendectomy specimens with the clinical diagnosis of acute appendicitis.

METHODS

This is a retrospective analysis of 238 appendectomies carried out in a single UK center between January and December 2013. The Histopathology reports of appendectomy specimens were retrieved.

RESULTS

A total of 238 appendectomies were performed during the study period. The mean age of the patients was 32 years (range, 7-81 years). Adult patients (>16 years) represented 79.4% of the study population. The female sex accounted for 46.6% of all the patients. Of the 238 resected appendix, 211 (88.7%) had histopathology findings consistent with appendicitis. Approximately 1.7% of the 238 specimens were abnormal pathologies other than inflammation of the appendix. The negative appendectomy (normal appendix on histology) rate was 11.3%. The female sex accounted for 59.1% of the negative appendectomies. Adults (>16 years) represented 77.8% of the negative appendectomies.

CONCLUSIONS

The observed high rates of negative appendectomy in the female sex can be reduced by utilizing combined clinical assessment and diagnostic imaging modalities. The findings of abnormal pathologies on histopathological examination of the appendix which could potentially impact on the management of the patients justify the current practice of routine histopathological examination of resected appendix.

Enteral contrast in the computed tomography diagnosis of appendicitis: comparative effectiveness in a prospective surgical cohort

OBJECTIVE

Our goal was to perform a comparative effectiveness study of intravenous (IV)-only versus IV + enteral contrast in computed tomographic (CT) scans performed for patients undergoing appendectomy across a diverse group of hospitals.

BACKGROUND

Small randomized trials from tertiary centers suggest that enteral contrast does not improve diagnostic performance of CT for suspected appendicitis, but generalizability has not been demonstrated. Eliminating enteral contrast may improve efficiency, patient comfort, and safety.

METHODS

We analyzed data for adult patients who underwent nonelective appendectomy at 56 hospitals over a 2-year period. Data were obtained directly from patient charts by trained abstractors. Multivariate logistic regression was utilized to adjust for potential confounding. The main outcome measure was concordance between final radiology interpretation and final pathology report.

RESULTS

A total of 9047 adults underwent appendectomy and 8089 (89.4%) underwent CT, 54.1% of these with IV contrast only and 28.5% with IV + enteral contrast. Pathology findings correlated with radiographic findings in 90.0% of patients who received IV + enteral contrast and 90.4% of patients scanned with IV contrast alone. Hospitals were categorized as rural or urban and by their teaching status. Regardless of hospital type, there was no difference in concordance between IV-only and IV + enteral contrast. After adjusting for age, sex, comorbid conditions, weight, hospital type, and perforation, odds ratio of concordance for IV + enteral contrast versus IV contrast alone was 0.95 (95% CI: 0.72-1.25).

CONCLUSIONS

Enteral contrast does not improve CT evaluation of appendicitis in patients undergoing appendectomy. These broadly generalizable results from a diverse group of hospitals suggest that enteral contrast can be eliminated in CT scans for suspected appendicitis.

Institutional review of patients presenting with suspected appendicitis

BACKGROUND

Appendicitis is a common gastrointestinal surgical emergency. Treatment balances the risks of negative appendicectomy (NA) against potential complicated appendicitis in determining clinical priority. This study reviewed the population characteristics, results of the diagnostic modalities and Alvarado score (AlvS) of patients with suspected appendicitis.

METHODS

A clinical audit of emergency appendicectomies was performed. Generalized linear models with a binomial distribution were used to evaluate the association between the age groups, gender, white cell count (WCC), neutrophil count (NC) and C-reactive protein (CRP) levels versus NAs and the different types of appendicitis. The utilization and accuracy of preoperative ultrasound and computed tomography (CT) and a preliminary analysis of AlvS were also evaluated.

RESULTS

Patients 17 to 24 years old had significantly higher odds of NA but lower odds of complicated appendicitis compared with patients above 40 years. Adult women and men had significantly higher odds of NA and suppurative appendicitis (SA), respectively. Only adults with SA and acute appendicitis had significantly higher odds of raised WCC, NC and CRP. The sensitivity of CT for adult females was high (100%). Patients who had CT and an AlvS of more than 7 did not have NAs.

CONCLUSION

Elevated WCC, NC and CRP were all associated with acute appendicitis and SA in adults only. CT is useful for refining the diagnosis in adult females. A combination of inflammatory markers, ultrasound and AlvS may be used selectively to complement or maximize the advantages of CT.

Improvement in the diagnosis of appendicitis

Our attempts to systematically improve accuracy in the evaluation of patients with suspected appendicitis are, in some ways, hindered by the fact that the condition is so frequently straightforward to diagnose. Careful history-taking and physical examination are reliable in most patients. However, establishing the diagnosis with these skills alone remains vulnerable to conditions that masquerade as acute appendicitis. A substantial body of clinical research over the last quarter-century has shown that improved accuracy is possible. Strategies for improvement include the use of diagnostic scoring systems, laboratory makers such as CRP, diagnostic laparoscopy, and advanced imaging modalities such as CT, MRI, and US. How clinicians use these strategies depends on many factors related to practice setting, the population served, and clinical goals. In children, for instance, the desire to limit exposure to ionizing radiation competes with the greater anatomic detail that a CT scan can provide; at the same time, many hospitals that treat children do not have the resources to maintain the sort of full-time, highly sophisticated abdominal US programs that achieve the highest rates of diagnostic accuracy in clinical studies. Trade-offs have to be made, but improvement is possible in almost all groups of patients: the clinical community should no longer settle for a 15% NA rate when 5% is clearly possible without adverse consequences. Many clinicians will be faced with the task of evaluating patients suspected of having acute appendicitis. A deliberate, proactive, and, ideally, benchmarked strategy for improving diagnosis should be the standard to which we hold ourselves and the promise we deliver to our patients.

Effect of the introduction of an emergency general surgery service on outcomes from appendicectomy

Background

Appendicectomy is a common general surgical emergency procedure and may be used as a surrogate marker to evaluate quality in surgical management. The aim of this study was to assess the outcomes of appendicectomy before and after the introduction of a consultant-led emergency general surgery (EGS) service at a large metropolitan tertiary referral centre.

Methods

A retrospective historical control study was performed that included all adult patients undergoing appendicectomy during two 18-month periods, before and after the introduction of the EGS service. Data collected included patient demographics, use of radiological investigations, time to surgery, length of hospital stay and histopathology findings. Outcome measures were time to surgery, hospital length of stay, use of radiological investigations, negative appendicectomy rate and perforation rate.

Results

A total of 675 patients were identified of whom 276 had an appendicectomy before the EGS service was introduced (2008–2009) and 399 after its introduction (2011–2012). The EGS service resulted in an increase in time to surgery (15 versus 18 h; P &lt; 0·001) with no increase in length of hospital stay (3 days for both periods; P = 0·424). An increase in the rate of appendicectomies performed within office hours was seen (54·3 versus 64·4 per cent; P &lt; 0·001), with no significant increase in negative appendicectomy (13·0 versus 15·8 per cent; P = 0·322) or perforation (8·3 versus 5·5 per cent; P = 0·149) rates. The use of preoperative computed tomography reduced from 38·4 to 26·6 per cent (P = 0·001).

Conclusion

The introduction of a consultant-led EGS service resulted in a decrease in the use of computed tomography and a greater proportion of appendicectomies performed within office hours, with no increase in length of stay. Overall negative appendicectomy and perforation rates did not change.

Biological effects of low-dose radiation from computed tomography scanning

PURPOSE

With the widespread use of computed tomography (CT), the risks of low-dose radiation from CT have been increasingly highlighted. This study aims to illustrate the CT-induced biological effects and analyze the potential beneficial or harmful outcomes so as to provide radiologists with reasonable advice on CT usage.

MATERIALS AND METHODS

The related literature was analyzed according to the topics of stochastic effect, hereditary effect, deterministic effect, accumulative injuries, hormesis and adaptive response; population epidemiology data were also analyzed.

RESULTS

CT accounts for 9% of X-ray examinations and approximately 40-67% of medical-related radiation, the dose is within the range of low-dose radiation (LDR). Two opposite viewpoints exist nowadays regarding the biological effects of CT scanning: They are either harmful or harmless. Approximately 0.6% and 1.5% of the cumulative cancer risk could be attributed to diagnostic X-rays in the UK and Germany, respectively. The probability of CT scans induced-cancer is about 0.7% and CT angiography's risk is around 0.13%. It is estimated that approximately 29,000 cancers could be related to CT scans in the USA every year. Meanwhile, another investigation of 25,104 patients who underwent 45,632 CT scans in 4 years showed that the majority of CT-induced cancers were accidents rather than certainties of frequent CT scans.

CONCLUSION

Although the LDR effects of CT are still controversial, the current problems include the high frequency-use and abuse of CT scans, the increase of radiation dose and accumulative dose in high-accuracy CT, and the poor understanding of carcinogenic risks. The underlying biological basis needs further exploring and the ratio of risks and benefits should be considered.

Progress in the diagnosis of appendicitis: a report from Washington State's Surgical Care and Outcomes Assessment Program

BACKGROUND AND OBJECTIVES

Studies suggest that computed tomography and ultrasonography can effectively diagnose and rule out appendicitis, safely reducing negative appendectomies (NAs); however, some within the surgical community remain reluctant to add imaging to clinical evaluation of patients with suspected appendicitis. The Surgical Care and Outcomes Assessment Program (SCOAP) is a physician-led quality initiative that monitors performance by benchmarking processes of care and outcomes. Since 2006, accurate diagnosis of appendicitis has been a priority for SCOAP. The objective of this study was to evaluate the association between imaging and NA in the general community.

METHODS

Data were collected prospectively for consecutive appendectomy patients (age > 15 years) at nearly 60 hospitals. SCOAP data are obtained directly from clinical records, including radiological, operative, and pathological reports. Multivariate logistic regression models were used to examine the association between imaging and NA. Tests for trends over time were also conducted.

RESULTS

Among 19,327 patients (47.9% female) who underwent appendectomy, 5.4% had NA. Among patients who were imaged, frequency of NA was 4.5%, whereas among those who were not imaged, it was 15.4% (P < 0.001). This association was consistent for men (3% vs 10%, P < 0.001) and for women of reproductive age (6.9% vs 24.7%, P < 0.001). In a multivariate model adjusted for age, sex, and white blood cell count, odds of NA for patients not imaged were 3.7 times the odds for those who received imaging (95% CI: 3.0-4.4). Among SCOAP hospitals, use of imaging increased and NA decreased significantly over time; frequency of perforation was unchanged.

CONCLUSIONS

Patients who were not imaged during workup for suspected appendicitis had more than 3 times the odds of NA as those who were imaged. Routine imaging in the evaluation of patients suspected to have appendicitis can safely reduce unnecessary operations. Programs such as SCOAP improve care through peer-led, benchmarked practice change.