Defining the current negative appendectomy rate: for whom is preoperative computed tomography making an impact?

The Rate of Negative Appendicectomy and Perforated Appendicitis As Quality Indicators of the General Surgical Service in a District General Hospital in Cavan, Republic of Ireland

Introduction Appendicitis is a common surgical condition that can be difficult to diagnose due to its varied clinical presentations. Surgical removal of the inflamed appendix is often necessary, and the appendix is sent for histopathological assessment to confirm the diagnosis. However, in some cases, the analysis may return a negative result for acute inflammation, known as a negative appendicectomy (NA). The definition of NA varies among experts. While negative appendicectomies are not ideal, they are accepted by surgeons to reduce the rate of perforated appendicitis, which can have severe consequences for patients. A study was conducted to investigate the rates of negative appendicectomies and their impact at a local district general hospital in Cavan, Republic of Ireland. Methods The study was conducted retrospectively from January 2014 to December 2019 on patients who were admitted with suspected appendicitis and underwent appendicectomy for appendicitis, regardless of age and sex. The researchers excluded patients who underwent elective, interval, and incidental appendicectomies. Data were collected on patient demographics, duration of symptoms prior to presentation, the intraoperative appearance of the appendix, and the histology results of the appendix specimens. Descriptive statistics and the Chi-squared test were used for data analysis with the help of IBM Statistical Package for the Social Sciences (SPSS) Version 26. Results The study retrospectively reviewed 876 patients who underwent an appendicectomy for suspected appendicitis between January 2014 and December 2019. The age distribution of patients was non-uniform, with 72% presenting before the third decade. The overall perforated appendicitis rate was 7.08%, and the overall negative appendicectomy (NA) rate was 21.3%. A subset analysis showed a statistically significant lower NA rate in females than in males. The NA rate decreased significantly over time and has been sustained since 2014 at around 10%, which is consistent with other published studies. The majority of the histology findings were uncomplicated appendicitis. Discussion This article discusses the challenges of diagnosing appendicitis and the need to reduce unnecessary surgeries. Laparoscopic appendectomy is the standard treatment, with an average cost of £2222.53 per patient in the UK. However, patients with negative appendicectomies (NA) have longer hospital stays and higher morbidity than uncomplicated cases, making it crucial to reduce unnecessary surgeries. The clinical diagnosis of appendicitis is not always straightforward, and the rate of perforated appendicitis increases with a longer duration of symptoms, particularly pain. The selective use of imaging in suspected appendicitis could reduce NA rates, but a statistical difference has not been proven. Scoring systems like the Alvarado score have limitations and cannot be relied upon alone. Retrospective studies have limitations, and biases and confounding variables must be considered. Conclusion The study found that a thorough investigation of patients, particularly with preoperative imaging, can decrease the rate of unnecessary appendectomies without increasing the rate of perforation. This could save costs and reduce harm to patients.

Infection or Inflammation: Are Uncomplicated Acute Appendicitis, Acute Cholecystitis, and Acute Diverticulitis Infectious Diseases?

Background: It is recognized increasingly that common surgical infections of the peritoneal cavity may be treated with antibiotic agents alone, or source control surgery with short-course antimicrobial therapy. By extension, testable hypotheses have emerged that such infections may not actually be infectious diseases, but rather represent inflammation that can be treated successfully with neither surgery nor antibiotic agents. The aim of this review is to examine extant data to determine which of uncomplicated acute appendicitis (uAA), uncomplicated acute calculous cholecystitis (uACC), or uncomplicated mild acute diverticulitis (umAD) might be amenable to management using supportive therapy alone, consistent with the principles of antimicrobial stewardship. Methods: Review of pertinent English-language literature and expert opinion. Results: Only two small trials have examined whether uAA can be managed with observation and supportive therapy alone, one of which is underpowered and was stopped prematurely because of challenging patient recruitment. Data are insufficient to determine the safety and efficacy of non-antibiotic therapy of uAA. Uncomplicated acute calculous cholecystitis is not primarily an infectious disease; infection is a secondary phenomenon. Even when bactibilia is present, there is no high-quality evidence to suggest that mild disease should be treated with antibiotic agents. There is evidence to indicate that antibiotic prophylaxis is indicated for urgent/emergency cholecystectomy for uACC, but not in the post-operative period. Uncomplicated mild acute diverticulitis, generally Hinchey 1a or 1b in current nomenclature, does not benefit from antimicrobial agents based on multiple clinical studies. The implication is that umAD is inflammatory and not an infectious disease. Non-antimicrobial management is reasonable. Conclusions: Among the considered disease entities, the evidence is strongest that umAD is not an infectious disease and can be treated without antibiotic agents, intermediate regarding uACC, and lacking for uAA. A plausible hypothesis is that these inflammatory conditions are related to disruption of the normal microbiome, resulting in dysbiosis, which is defined as an imbalance of the natural microflora, especially of the gut, that is believed to contribute to a range of conditions of ill health. As for restorative pre- or probiotic therapy to reconstitute the microbiome, no recommendation can be made in terms of treatment, but it is not recommended for prevention of primary or recurrent disease.

DIAgnostic iMaging or Observation in early equivocal appeNDicitis (DIAMOND): open-label, randomized clinical trial

BACKGROUND

Mild appendicitis may resolve spontaneously. The use of CT may lead to an overdiagnosis of uncomplicated appendicitis. The aims of this study were to examine whether early imaging results in more patients being diagnosed with acute appendicitis than initial observation, and to study the safety and feasibility of score-based observation compared with imaging in patients with equivocal signs of appendicitis.

METHODS

Patients with suspected appendicitis with symptoms for fewer than 24 h and an Adult Appendicitis Score of 11-15 were eligible for this trial. After exclusions, patients were randomized openly into two equal-sized groups: imaging and observation. Patients in the imaging group had ultrasound imaging followed by CT when necessary, whereas those in the observation group were reassessed after 6-8 h with repeated scoring and managed accordingly. The primary outcome was the number of patients requiring treatment for acute appendicitis within 30 days.

RESULTS

Ninety-three patients were randomized to imaging and 92 to observation; after exclusions, 93 and 88 patients respectively were analysed. In the imaging group, more patients underwent treatment for acute appendicitis than in the observation group: 72 versus 57 per cent (difference 15 (95 per cent c.i. 1 to 29) per cent). This suggests that patients with spontaneously resolving appendicitis were not diagnosed or treated in the observation group. Some 55 per cent of patients in the observation group did not need diagnostic imaging within 30 days after randomization. There was no difference in the number of patients diagnosed with complicated appendicitis (4 versus 2 per cent) or negative appendicectomies (1 versus 1 per cent) in the imaging and observation groups.

CONCLUSION

Score-based observation of patients with early equivocal appendicitis results in fewer patients requiring treatment for appendicitis. Registration number: NCT02742402 (http://www.clinicaltrials.gov).

A Dual-Institutional Study on First Year Practice Outcomes of Pediatric Surgeons Who Trained in the Era of Work Hour Restrictions

BACKGROUND

In July 2003, an 80-h work week restriction for residencies was mandated. This was met with skepticism regarding its potential impact on operative training. We hypothesized no difference in outcomes for pediatric surgeons who trained under duty hour restrictions compared to historical complication rates.

METHODS

Dual-institutional review of pediatric patients who underwent five of the most common operations (2013-2018) by first-year pediatric surgeons who trained under duty hour restrictions was performed. Tests of proportions were used to compare complication rates to published rates on data collected prior to 2003.

RESULTS

Patient mean age was 10.1 years. No significant differences (p values > 0.05) were found in laparoscopic appendectomy rates of infection, bleeding or intra-abdominal abscess compared to previously published rates. Pyloromyotomy rates of infection or duodenal perforation were not different. No differences were detected in rates of infection, recurrence or testicular atrophy for inguinal hernia repair. Umbilical hernia rates of infection, bleeding, and recurrence were also not different. There was no difference in CVC rates of hemopneumothoraces; significantly more bleeding events were detected (1.2% vs. 0.1%; p value = 0.04).

CONCLUSION

In this study, first-year complication rates of pediatric surgeons who trained under duty hour restrictions were not significantly different when compared to published rates.

Non-Operative Management of Appendicitis: Evolution, not Revolution

Background: The medical fascination with the appendix vermiformis dates from the clandestine prosectors of the fifteenth century. The surgical management of appendiceal inflammation dates from 1735, but acceptance that acute appendicitis (AA) should be treated primarily by resection with or without drainage would not follow for 150 years. Recent publication of several randomized clinical trials (RCTs) of non-operative management (NOM) of AA affords the opportunity to review the historical record, describe the evolution of AA management toward NOM, and assess what is in the best interest of the patient. Methods: Review and synthesis of historical and contemporary English, French, German, and Italian literature with expert opinion. Results: Modern understanding of AA dates to the landmark 1886 clinico-pathologic correlative study by Reginald Fitz, which coined the term appendicitis and coincided with recognition by surgeons that AA could be diagnosed pre-operatively and managed surgically, with mortality rates of approximately 10%. Not until 1901 did Albert Ochsner advocate NOM, paradoxically for severe cases unlikely to survive operation. Markedly decreased mortality coincided with the introduction of sulfanilamide in 1935 and penicillin and curare in 1942. The first large series of patients with AA treated primarily with NOM was published in 1956 by Eric Coldrey. Modern management evolved rapidly in the late twentieth century, including effective anti-anaerobic antibiotic agents (1970s), laparoscopic appendectomy (LA; 1980), and pelvis computed tomography with rectal contrast (1998) all representing important contributions. Randomized controlled trials of NOM of AA date to 1995, with one large trial (2015) showing that open appendectomy was not non-inferior to NOM, and another (2020) demonstrating non-inferiority between (mostly) LA and NOM. However, one-year failure rates are high (∼30%) and appear to increase further with longer follow-up. Conclusions: Laparoscopic appendectomy is curative and cost-effective management for AA, with low morbidity. Results of recent RCTs of NOM of AA indicate that LA remains the treatment of choice, particularly if a fecalith is present. However, patient preferences must be taken into account; some may prefer NOM for the 60%-70% chance that surgery may be avoided, which should be considered when providing informed consent. Non-operative management should be undertaken in the outpatient setting if possible. Antibiotic management-whether or not for NOM-should adhere to the principles of stewardship.

Clinical Significance of Variable Histomorphologic Findings Related to Mucosal Inflammation in Negative Appendectomy

The aim of the study was to investigate the clinical significance of various histomorphologic findings related to mucosal inflammation in negative appendectomy. We reviewed histopathologic findings of 118 negative appendectomies and correlated them with the appendicitis inflammatory response (AIR) score and appendiceal diameter. Among 118 patients with negative appendectomy, 94 (80%), 73 (78%) and 89 (75%) patients displayed mucosal inflammation, high neutrophil score (neutrophil count ≥10/5 high power field and surface epithelial flattening, respectively. Out of 118 patients with negative appendectomy, mucosal inflammation, high neutrophil score and surface epithelial flattening were associated with higher risk group according to the appendicitis inflammatory response (AIR) score (p < 0.05, respectively). In addition, mucosal inflammation, high neutrophil score and surface epithelial flattening were frequently detected in 118 negative appendectomies, compared with 24 incidental appendectomies (p < 0.05, respectively). In an analysis of 77 negative appendectomy patients with appendiceal diameter data available, increased appendiceal diameter was positively correlated with luminal inflammation, high neutrophil score and surface epithelial flattening (p < 0.05, respectively). In conclusion, mucosal inflammation, high neutrophil score and surface epithelial flattening in negative appendectomy may be relevant to patients’ signs and symptoms, especially in cases with no other cause of the abdominal pain.

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)

Current opinions and practices for the management of acute appendicitis: an international survey

BACKGROUND

In recent decades the management of acute appendicitis has evolved significantly. Improved access to early imaging and better clinical scoring algorithms have resulted in less negative appendicectomy rates. In addition, non-operative management has become increasingly utilized. The aim of this study was to assess the variability of management of acute appendicitis globally.

METHODS

This was a multi-national targeted survey of general surgeons across 39 countries. A structured set of questions was utilized to delineate nuances between management styles of consultants and trainees. Opinions on the pathological diagnosis of appendicitis, acceptable negative appendicectomy rates, and the role of non-operative treatment of appendicitis (NOTA) were surveyed.

RESULTS

A total of 304 general surgeons responded to this survey, 42% of which were consultants/attendings. Sixty-nine percent advocated that a histologically normal appendix was the most appropriate definition of a negative appendicectomy, while 29% felt that anything other than inflammation, necrosis, gangrene, or perforation was more appropriate. Forty-three percent felt that negative appendicectomy rates should be less than 10%, with 41% reporting that their own negative appendicectomy rate was < 5%. Interestingly, only 17% reported routinely using NOTA for uncomplicated appendicitis, with one-fifth stating that they would undergo NOTA if they themselves had uncomplicated appendicitis.

CONCLUSION

This study represents the largest sampling of management strategies for acute appendicitis. It shows substantial global heterogeneity between clinicians regarding what constitutes a negative appendicectomy as well as the appropriateness of non-operative management.

Accuracies of Diagnostic Methods for Acute Appendicitis

The objectives were to evaluate the effectiveness of ultrasonography, computed tomography, and physical examination for diagnosing acute appendicitis with analyzing their accuracies and negative appendectomy rates in a clinical rather than research setting. A total of 2763 subjects were enrolled. Sensitivity, specificity, positive predictive value, and negative predictive value and negative appendectomy rate for ultrasonography, computed tomography, and physical examination were calculated. Confirmed positive acute appendicitis was defined based on pathologic findings, and confirmed negative acute appendicitis was defined by pathologic findings as well as on clinical follow-up. Sensitivity, specificity, positive predictive value, and negative predictive value for ultrasonography were 99.1, 91.7, 96.5, and 97.7 per cent, respectively; for computed tomography, 96.4, 95.4, 95.6, and 96.3 per cent, respectively; and for physical examination, 99.0, 76.1, 88.1, and 97.6 per cent, respectively. The negative appendectomy rate was 5.8 per cent (5.2% in the ultrasonography group, 4.3% in the computed tomography group, and 12.2% in the physical examination group). Ultrasonography/computed tomography should be performed routinely for diagnosis of acute appendicitis. However, in view of its advantages, ultrasonography should be performed first. Also, if the result of a physical examination is negative, imaging studies after physical examination can be unnecessary.

Diagnostic utility of fecal calprotectin in patients presenting to the emergency department with suspected acute appendicitis

BACKGROUND

Acute appendicitis (AA) is one of the most common diseases faced by the surgeon in the emergency department. In clinical practice, how to diagnose patients with AA accurately is still challenging.

METHODS

We conducted a prospective study of 84 patients who presented in the emergency department with suspected AA and measured fecal calprotectin (FC) value. The final diagnosis of AA was independently determined without reference to the test results of FC. Then, we retrospectively analyzed the FC value for identifying AA.

RESULTS

FC value in patients with AA were significantly higher than that in patients without AA (240.5 vs. 68.5 ug/g, P < 0.001). Receiver-operating characteristic analyses demonstrated FC value to be highly sensitive and specific for the diagnosis of AA, as indicated by an overall area under the curve (AUC) of 0.928 (500 times of boot strap estimated 95% CI, 0.855-0.972), with an optimal cut off point of 106 ug/g. FC levels in 26 patients with simple AA were significantly lower than it in the 14 patients with suppurative AA (206 vs. 304ug/g, P = 0.001).

CONCLUSIONS

FC test provides a sensitive, convenient and economical method to help facilitate the diagnosis of AA in emergency department. Especially for hospitals without computed tomography equipment or patients who are not suitable to exposed to radiation, FC test is of great significance for improving the diagnostic accuracy of AA.

Computed tomography for diagnosis of acute appendicitis in adults

BACKGROUND

Diagnosing acute appendicitis (appendicitis) based on clinical evaluation, blood testing, and urinalysis can be difficult. Therefore, in persons with suspected appendicitis, abdominopelvic computed tomography (CT) is often used as an add-on test following the initial evaluation to reduce remaining diagnostic uncertainty. The aim of using CT is to assist the clinician in discriminating between persons who need surgery with appendicectomy and persons who do not.

OBJECTIVES

Primary objective Our primary objective was to evaluate the accuracy of CT for diagnosing appendicitis in adults with suspected appendicitis. Secondary objectives Our secondary objectives were to compare the accuracy of contrast-enhanced versus non-contrast-enhanced CT, to compare the accuracy of low-dose versus standard-dose CT, and to explore the influence of CT-scanner generation, radiologist experience, degree of clinical suspicion of appendicitis, and aspects of methodological quality on diagnostic accuracy.

SEARCH METHODS

We searched MEDLINE, Embase, and Science Citation Index until 16 June 2017. We also searched references lists. We did not exclude studies on the basis of language or publication status.

SELECTION CRITERIA

We included prospective studies that compared results of CT versus outcomes of a reference standard in adults (> 14 years of age) with suspected appendicitis. We excluded studies recruiting only pregnant women; studies in persons with abdominal pain at any location and with no particular suspicion of appendicitis; studies in which all participants had undergone ultrasonography (US) before CT and the decision to perform CT depended on the US outcome; studies using a case-control design; studies with fewer than 10 participants; and studies that did not report the numbers of true-positives, false-positives, false-negatives, and true-negatives. Two review authors independently screened and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected the data from each study and evaluated methodological quality according to the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate random-effects model to obtain summary estimates of sensitivity and specificity.

MAIN RESULTS

We identified 64 studies including 71 separate study populations with a total of 10,280 participants (4583 with and 5697 without acute appendicitis). Estimates of sensitivity ranged from 0.72 to 1.0 and estimates of specificity ranged from 0.5 to 1.0 across the 71 study populations. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.93 to 0.96), and summary specificity was 0.94 (95% CI 0.92 to 0.95). At the median prevalence of appendicitis (0.43), the probability of having appendicitis following a positive CT result was 0.92 (95% CI 0.90 to 0.94), and the probability of having appendicitis following a negative CT result was 0.04 (95% CI 0.03 to 0.05). In subgroup analyses according to contrast enhancement, summary sensitivity was higher for CT with intravenous contrast (0.96, 95% CI 0.92 to 0.98), CT with rectal contrast (0.97, 95% CI 0.93 to 0.99), and CT with intravenous and oral contrast enhancement (0.96, 95% CI 0.93 to 0.98) than for unenhanced CT (0.91, 95% CI 0.87 to 0.93). Summary sensitivity of CT with oral contrast enhancement (0.89, 95% CI 0.81 to 0.94) and unenhanced CT was similar. Results show practically no differences in summary specificity, which varied from 0.93 (95% CI 0.90 to 0.95) to 0.95 (95% CI 0.90 to 0.98) between subgroups. Summary sensitivity for low-dose CT (0.94, 95% 0.90 to 0.97) was similar to summary sensitivity for standard-dose or unspecified-dose CT (0.95, 95% 0.93 to 0.96); summary specificity did not differ between low-dose and standard-dose or unspecified-dose CT. No studies had high methodological quality as evaluated by the QUADAS-2 tool. Major methodological problems were poor reference standards and partial verification primarily due to inadequate and incomplete follow-up in persons who did not have surgery.

AUTHORS' CONCLUSIONS

The sensitivity and specificity of CT for diagnosing appendicitis in adults are high. Unenhanced standard-dose CT appears to have lower sensitivity than standard-dose CT with intravenous, rectal, or oral and intravenous contrast enhancement. Use of different types of contrast enhancement or no enhancement does not appear to affect specificity. Differences in sensitivity and specificity between low-dose and standard-dose CT appear to be negligible. The results of this review should be interpreted with caution for two reasons. First, these results are based on studies of low methodological quality. Second, the comparisons between types of contrast enhancement and radiation dose may be unreliable because they are based on indirect comparisons that may be confounded by other factors.

Evaluation of the diagnostic performance of a decision tree model in suspected acute appendicitis with equivocal preoperative computed tomography findings compared with Alvarado, Eskelinen, and adult appendicitis scores: A STARD compliant article

This study evaluated the diagnostic performance of a new clinical approach based on decision tree (DT) analysis in adult patients with equivocal computed tomography (CT) findings of acute appendicitis (AA) compared with previous scoring systems.This retrospective study of 244 adult patients with equivocal CT findings included appendicitis (AG, n = 80) and non-appendicitis (NAG, n = 164) groups. The chi-squared automatic interaction detection algorithm was for AA prediction. A receiver operating characteristic curve analysis and area under the curve (AUC) were used to compare the DT analysis with Alvarado, Eskelinen score, and adult appendicitis scores (AAS).The following factors were selected for AA prediction: rebound tenderness severity, migration, urinalysis, symptom duration, leukocytosis, neutrophil count, and C-reactive protein levels. The DT comprised 11 final nodes with the following AA probabilities: node 1, 100% (16/16); node 2, 90% (9/10); node 3, 80% (8/10); node 4, 60.9% (14/23); node 5, 50% (3/6); node 6, 43.8% (7/16); node 7, 22.6% (12/53); node 8, 13% (10/77); node 9, 5.6% (1/18); node 10, 0% (0/12); and node 11, 0% (0/3). The AUC of the DT was higher (0.850 [95% confidence interval {CI}; 0.799-0.893]) than the Alvarado score (0.695 [95% CI; 0.633-0.752]), AAS (0.749 [95% CI; 0.690-0.802]), and the Eskelinen score (0.715 [95% CI; 0.654-0.770]). The results were statistically significant when compared with the AUCs of the Alvarado score, Eskelinen score, and AAS (P < .001, P < .001, P = .003, respectively).The DT-based approach facilitated AA diagnosis and determination of clinical status in patients with equivocal preoperative CT findings and ambiguous results.

The Impact of Pathological Criteria on Pediatric Negative Appendectomy Rate

INTRODUCTION

Negative appendectomy rate (NAR) is a quality metric used in the surgical management of appendicitis. The rates of negative appendectomy (NA) in children range anywhere from 1% to 40% in the literature. Many reports do not provide clear pathological definitions for either appendicitis or NA on which they base their calculation of NAR. We reviewed our experience with pediatric appendectomy and the pathological spectrum encompassed within our definition of a NA and examined how the pathologic definition impacts our hospital's NAR.

METHODS

A retrospective review from 2012 to 2016 in a single institution identified 1676 children that underwent appendectomy. Average age was 11.4 (2-18 years). Patient demographics, clinical outcomes and pathological findings were collected. At our institution, appendicitis is defined as the presence of transmural acute inflammation in the appendix and those patients without this finding have been considered to have had a negative appendectomy.

RESULTS

1435 patients underwent appendectomy for presumed appendicitis. The rate of pathologically diagnosed appendicitis was 91.1% (1307/1435) and as such, the NAR was 8.9% (128/1435). Review of the pathology of the NA cohort identified 67/128 (52.3%) patients with completely normal pathology. The remaining 61 patients displayed some sort of pathological abnormality including malignancy (n = 2), fecaliths (n = 9), pinworms (n = 3), granuloma (n = 2), fibrous obliteration (n = 4), isolated periappendiceal inflammation (n = 1), and acute inflammation confined to the mucosa (n = 40). Exclusion of these patients with abnormal pathology decreased the NAR to 4.6%. Patients with pathological abnormalities of the appendix other than transmural inflammation had a higher rate of 30-day readmission than patients with acute appendicitis (8.2% versus 4.5% p < 0.01).

CONCLUSION

Pediatric NAR is dependent upon the pathological definition of appendicitis and negative appendectomy. Institutional variation in definition may explain discrepancies in the literature. By example, including only those that show "the absence of inflammation or other appendiceal pathology" would decrease our NAR by 50%. This study calls into question the interpretation of interhospital NAR and the use of NAR as a quality metric in the management of appendicitis. Retrospective comparative study: Level III evidence.

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.

Logistic regression model to predict acute uncomplicated and complicated appendicitis

INTRODUCTION

While patients with acute uncomplicated appendicitis may be treated conservatively, those who suffer from complicated appendicitis require surgery. We describe a logistic regression equation to calculate the likelihood of acute uncomplicated appendicitis and complicated appendicitis in patients presenting to the emergency department with suspected acute appendicitis.

MATERIALS AND METHODS

A cohort of 895 patients who underwent appendicectomy were analysed retrospectively. Depending on the final histology, patients were divided into three groups; normal appendix, acute uncomplicated appendicitis and complicated appendicitis. Normal appendix was considered the reference category, while acute uncomplicated appendicitis and complicated appendicitis were the nominal categories. Multivariate and univariate regression models were undertaken to detect independent variables with significant odds ratio that can predict acute uncomplicated appendicitis and complicated appendicitis. Subsequently, a logistic regression equation was generated to produce the likelihood acute uncomplicated appendicitis and complicated appendicitis.

RESULTS

Pathological diagnosis of normal appendix, acute uncomplicated appendicitis and complicated appendicitis was identified in 188 (21%), 525 (59%) and 182 patients (20%), respectively. The odds ratio from a univariate analysis to predict complicated appendicitis for age, female gender, log2 white cell count, log2 C-reactive protein and log2 bilirubin were 1.02 (95% confidence interval, CI, 1.01, 1.04), 2.37 (95% CI 1.51, 3.70), 9.74 (95% CI 5.41, 17.5), 1.57 (95% CI 1.40, 1.74), 2.08 (95% CI 1.56, 2.76), respectively. For the same variable, similar odds ratios were demonstrated in a multivariate analysis to predict complicated appendicitis and univariate and multivariate analysis to predict acute uncomplicated appendicitis.

CONCLUSIONS

The likelihood of acute uncomplicated appendicitis and complicated appendicitis can be calculated by using the reported predictive equations integrated into a web application at www.appendistat.com. This will enable clinicians to determine the probability of appendicitis and the need for urgent surgery in case of complicated appendicitis.

Pitfalls of Diagnosing Left Lower Quadrant Pain Causes: Making the Uncommon Common Again

BACKGROUND Left-sided acute appendicitis, although well described in the literature, is still an easily missed diagnosis. Midgut malrotation and situs inversus are 2 known leading conditions that contribute to misdiagnosis of appendicitis. CASE REPORT Here is the case of a 27-year-old male without any previous medical history, who presented with left lower quadrant tenderness and was misdiagnosed with gastroenteritis as an outpatient and sent home; the patient presented the next day to the emergency department where he was found to have acute appendicitis with situs inversus. He underwent laparoscopic appendectomy where a phlegmon was identified. Pathology came back as peri-appendiceal mucocele with no signs of malignancy. CONCLUSIONS This case report aimed to revisit the idea of left-sided acute appendicitis and discuss the management of a perforated appendiceal mucocele contained by a phlegmon.

Laparoscopic Appendectomy in the Setting of Clinical Prediction Rules

PURPOSE

Acute appendicitis (AA) is the most frequent surgical entity in the emergency department, but its correct diagnosis remains challenging. To improve diagnosis, clinical prediction rules (CPRs) have been created to establish objective scores for the probability of suffering AA. In this study, we establish scores indicating whether laparoscopy would be superior to clinical observation or repeat diagnostic test.

METHODS

A retrospective observational study was conducted with 433 patients submitted to surgery for suspected AA using a laparoscopic approach. The Alvarado, Raja Isteri Pengiran Anak Saleha Appendicitis, appendicitis inflammatory response, and adult appendicitis score scales were applied in each case to establish a high, medium, or low probability of suffering AA.

RESULTS

Of the 433 patients analyzed, 381 (88.0%) had AA. Twelve (2.8%) were converted to open surgery, and complications were observed in 54 (12.5%) cases. The CPRs studied showed statistically significant differences between AA and negative appendectomies. However, in patients with intermediate probability scores, the diagnostic accuracy of the CPRs evaluated was not adequate.

CONCLUSIONS

Laparoscopic surgery can serve as a diagnostic tool for patients with intermediate AA probability scores because of its low associated morbidity and mortality and because it affords a direct diagnosis of the problem, allowing determination of the appropriate treatment.

Unusual Histopathological Findings in Appendectomy Specimens: A Retrospective Analysis of 2047 Cases

Background. In this study, we retrospectively evaluated cases of patients who had undergone appendectomy in our hospital and aimed to present the efficiency of diagnostic tests and demographic data of cases. Pathological reports were analyzed for the following parameters: age, gender, and pathological diagnosis. In addition, the demographic and clinicopathologic characteristics of patients with unusual histopathologic findings were evaluated in detail, and reanalysis of archived resected appendix specimens was carried out. Methods. Files of 2047 patients (1329 males, 718 females, sex ratio: 1.85, age range: 1-87 years, mean age: 26, 50 years), who had been operated with a diagnosis of acute appendicitis in the emergency department of Bezmialem Vakıf University Medical Faculty from November 2011 to June 2014, were retrospectively evaluated. Results. Cases were separated into 2 groups. Cases with histopathologic examination reported as acute appendicitis constituted group 1 (n = 2013, 98.34%), and cases with pathologic findings other than acute appendicitis constituted group 2 (n = 34, 1.66%). The second group consisted of 8 low-grade mucinous neoplasms, 7 mucoceles, 6 carcinoid, 5 granulomatous inflammation, 4 intraluminal Enterobius vermicularis, 1 endometriosis externa, 1 adenocarcinoma infiltrated to serosa, 1 mesenteric cyst, and 1 low-grade adenocarcinoma formed in mucinous cystic neoplasm background. Conclusion. Acute appendicitis is the most common emergency surgical condition. Although most of the resected appendectomy specimens showed typical histopathologic findings, some (1.66%) showed unusual histopathologic findings. Even if the macroscopic appearance of the specimen is normal or acute appendicitis, we suggest routine histopathological examination.

The Accuracy of the Computed Tomography Diagnosis of Acute Appendicitis: Does the Experience of the Radiologist Matter?

Background and Aims:

To assess the accuracy of computed tomography in diagnosing acute appendicitis with a special reference to radiologist experience.

Material and Methods:

Data were collected prospectively in our randomized controlled trial comparing surgery and antibiotic treatment for uncomplicated acute appendicitis (APPAC trial, NCT01022567). We evaluated 1065 patients who underwent computed tomography for suspected appendicitis. The on-call radiologist preoperatively analyzed these computed tomography images. In this study, the radiologists were divided into experienced (consultants) and inexperienced (residents) ones, and the comparison of interpretations was made between these two radiologist groups.

Results:

Out of the 1065 patients, 714 had acute appendicitis and 351 had other or no diagnosis on computed tomography. There were 700 true-positive, 327 true-negative, 14 false-positive, and 24 false-negative cases. The sensitivity and the specificity of computed tomography were 96.7% (95% confidence interval, 95.1–97.8) and 95.9% (95% confidence interval, 93.2–97.5), respectively. The rate of false computed tomography diagnosis was 4.2% for experienced consultant radiologists and 2.2% for inexperienced resident radiologists (p = 0.071). Thus, the experience of the radiologist had no effect on the accuracy of computed tomography diagnosis.

Conclusion:

The accuracy of computed tomography in diagnosing acute appendicitis was high. The experience of the radiologist did not improve the diagnostic accuracy. The results emphasize the role of computed tomography as an accurate modality in daily routine diagnostics for acute appendicitis in all clinical emergency settings.

Laparoscopic appendectomy for acute appendicitis: How to discourage surgeons using inadequate therapy

Acute appendicitis (AA) develops in a progressive and irreversible manner, even if the clinical course of AA can be temporarily modified by intentional medications. Reliable and real-time diagnosis of AA can be made based on findings of the white blood cell count and enhanced computed tomography. Emergent laparoscopic appendectomy (LA) is considered as the first therapeutic choice for AA. Interval/delayed appendectomy at 6-12 wk after disease onset is considered as unsafe with a high recurrent rate during the waiting time. However, this technique may have some advantages for avoiding unnecessary extended resection in patients with an appendiceal mass. Non-operative management of AA may be tolerated only in children. Postoperative complications increase according to the patient’s factors, and temporal avoidance of emergent general anesthesia may be beneficial for high-risk patients. The surgeon’s skill and cooperation of the hospital are important for successful LA. Delaying appendectomy for less than 24 h from diagnosis is safe. Additionally, a semi-elective manner (i.e., LA within 24 h after onset of symptoms) may be paradoxically acceptable, according to the factors of the patient, physician, and institution. Prompt LA is mandatory for AA. Fortunately, the Japanese government uses a universal health insurance system, which covers LA.

Clinical and laboratory findings in the diagnosis of right lower quadrant abdominal pain: outcome analysis of the APPAC trial

BACKGROUND

The current research on acute appendicitis aims to improve the diagnostics and to clarify to whom antibiotic treatment might be the treatment of choice.

METHODS

The present study is a retrospective analysis of a prospectively collected data in our randomized multicenter trial comparing surgery and antibiotic treatment for acute uncomplicated appendicitis (APPAC trial, NCTO1022567). We evaluated 1321 patients with a clinical suspicion of acute appendicitis, who underwent computed tomography (CT). Age, gender, body temperature, pain scores, the duration of symptoms, white blood cell count (WBC) and C-reactive protein (CRP) were recorded on admission.

RESULTS

CT confirmed the diagnosis of acute appendicitis in 73% (n=970) and in 27% (n=351) it revealed no or other diagnosis. Acute appendicitis patients had significantly higher WBC levels than patients without appendicitis (median 12.2 and 10.0, respectively, p<0.0001), whereas CRP levels did not differ between the two groups. Ideal cut-off points were assessed with receiver operating characteristic (ROC) curves, but neither these markers or neither their combination nor any clinical characteristic could accurately differentiate between patients with acute appendicitis and those without. The proportion of patients with normal WBC count and CRP was significantly (p=0.0007) lower in patients with acute appendicitis than in patients without appendicitis.

CONCLUSIONS

Both clinical findings and laboratory tests are unable to reliably distinguish between patients with acute appendicitis and those without. If both WBC count and CRP are normal, acute appendicitis is very unlikely. The current results emphasize the role of CT imaging in patients with suspected acute appendicitis.

Is acute appendicitis still misdiagnosed?

Objective

The optimal diagnostics and treatment of acute appendicitis continues to be a challenge. A false positive diagnosis of appendicitis may lead to an unnecessary operation, which has been appropriately termed negative appendectomy. The aim of our study was to identify the effectiveness of preoperative investigations in preventing negative appendectomy.

Methods

A retrospective study was performed on adult patients who underwent operation for suspected acute appendicitis from 2008 to 2013 at Vilnius University Hospital Santariskiu Klinikos. Patients were divided into two groups: group A underwent an operation, where appendix was found to be normal (non-inflamed); group B underwent an appendectomy for inflamed appendix. Groups were compared for preoperative data, investigations, treatment results and pathology findings.

Results

554 patients were included in the study. Preoperative laboratory tests results of hemoglobin, hematocrit concentrations and white blood cell count were significantly higher in group B (p<0.001). Ultrasonography was performed for 78 % of patients in group A and 74 % in group B and did not provide any statistically significant results. Comparing Alvarado score results, there were more patients with Alvarado score less than 7 in group A than in group B. In our large series we could find only four independent risk factors, and they could only account for 24 % of cases.

Conclusions

In summary, acute appendicitis is still often misdiagnosed and the ratio of negative appendectomies remains rather high. Additional investigations such as observation and computed tomography should be used to prevent this.

Is preoperative distinction between complicated and uncomplicated acute appendicitis feasible without imaging?

BACKGROUND

One of the main aims of appendicitis research is the differential diagnostics between complicated and uncomplicated acute appendicitis that enable provision of the optimal treatment for each patient.

METHODS

Data in the present study were collected prospectively in our randomized antibiotic treatment for uncomplicated acute appendicitis trial (APPAC) comparing surgery and antibiotic treatment for uncomplicated acute appendicitis (NCT01022567). We evaluated 705 patients who had acute appendicitis on computed tomography. Patients with uncomplicated acute appendicitis (n = 368) were compared with all complicated acute appendicitis patients (n = 337), and subgroup analyses were performed between uncomplicated acute appendicitis and an appendicolith appendicitis (CA1; n = 256) and uncomplicated acute appendicitis and perforation and/or abscess (CA2; n = 78). Age, sex, body temperature (°C), duration of symptoms, white blood cell count (E9/L), and C-reactive protein (mg/L) were recorded on admission. Receiver operating characteristic curves were calculated for white blood cell count, C-reactive protein, and temperature.

RESULTS

CA2 patients had significantly greater C-reactive protein levels (mean 122 and 47, respectively, P < .001) and longer duration of symptoms than uncomplicated acute appendicitis patients; 81% of CA2 patients and 38% of uncomplicated acute appendicitis patients had symptoms >24 hours before admission (P < .001). In receiver operating characteristic analysis, C-reactive protein and temperature had clinically significant results only in comparison with uncomplicated acute appendicitis and CA2 (area under the curve >0.7), but no optimum cutoff points could be identified.

CONCLUSION

In clinical decision making, neither clinical findings nor laboratory markers are reliable enough to estimate the severity of the acute appendicitis accurately or to determine the presence of an appendicolith. The current results emphasize the role of computed tomography in the differential diagnosis of complicated and uncomplicated acute appendicitis.

Protocol for suspected pediatric appendicitis limits computed tomography utilization

BACKGROUND

Despite radiation concerns, computed tomography (CT) remains the favored imaging modality at many children's hospitals for appendicitis. We sought to reduce CT utilization for appendicitis in a children's hospital with an algorithm relying on 24-h ultrasound (US) as the primary imaging study.

MATERIALS AND METHODS

An US-based protocol for suspected appendicitis was adopted at the end of the fiscal year (FY) 2011. Data were collected for 12 mo before and 24 mo after implementation. Imaging test usage and charges were adjusted per annual number of appendectomies. Training of emergency department staff continued over 1 y after protocol implementation.

RESULTS

For FY 2011, 644 abdominal CT and 1088 appendix US were ordered, and 249 laparoscopic appendectomies (LAs) were performed. After protocol implementation, FY 2012: 535 CT, 1285 US, and 265 LA were performed; and FY 2013: 330 CT, 1235 US, and 236 LA were performed. Length of stay decreased from before to after protocol (2.57 ± 0.29 versus 2.15 ± 0.11 d), P < 0.001. CTs per appendectomy decreased 42% from FY 2011 to FY 2013 (2.43 versus 1.40, P < 0.001) and 30% from before to after protocol (2.43 versus 1.70, P < 0.001). A corresponding 27% increase in number of US before to after protocol (4.11 versus 5.20 US/appendectomy, P = 0.004) occurred. CT and US charges decreased $2253 and $6633 per appendectomy for FY 2012 and 2013, respectively.

CONCLUSIONS

Protocol-driven workup with US significantly reduced CT utilization, radiation exposure, and imaging-related charges in children with suspected appendicitis. Ongoing training of emergency department staff is required to ensure protocol compliance.

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.

How to evaluate appendices with borderline diameters on CT: proposal of a quick solution to overcome the limitations of the established CT criteria

RATIONALE AND OBJECTIVES

To propose a useful computed tomography (CT) criterion, the diameter with compression (DWC), especially in appendices with borderline diameters.

MATERIALS AND METHODS

We retrospectively collected 216 patients with visible appendices on CT after clinicopathologic confirmation of appendicitis. Each CT criterion of appendicitis was evaluated by an experienced abdominal radiologist: maximal outer diameter (MOD), DWC, mural thickness and enhancement, periappendiceal infiltration, and appendicolith. DWC is the expected diameter after deduction of the intraluminal compressible contents such as air and feces. All the CT criteria were compared in the appendicitis and nonappendicitis group.

RESULTS

The areas under the receiver operating characteristic curve (AUC) of the MOD and the DWC were 0.967 and 0.973, respectively. The optimal cutoff value was 8.2 mm for the MOD and 6.6 mm for the DWC. Twenty-five of the 80 appendicitis patients (31.2%) and 62 of the 136 nonappendicitis patients (45.6%) had MODs between 5.7 mm and 9.8 mm in the overlap between the two groups. In this overlap, the AUC of the MODs declined sharply to 0.767, whereas the AUC of the DWCs remained 0.923. Use of the criterion of DWC >6.6 mm yielded a sensitivity of 84.0%, a specificity of 88.7%, and an accuracy of 87.4%. There were no other criteria with both sensitivity and specificity >80% in the range of overlap.

CONCLUSIONS

The proposed CT criterion of the DWC is not affected by normal distension or periappendiceal inflammation but only by true appendicitis. Therefore, DWC can improve the diagnostic performance of appendicitis regardless of the MOD.

Acute appendicitis in children: ultrasound and CT findings in negative appendectomy cases

BACKGROUND

To decrease the negative appendectomy rate in children, knowledge of the misleading imaging findings on US and CT in negative appendicitis cases is important.

OBJECTIVE

To evaluate the negative appendectomy rate and describe the imaging findings of US and CT that lead radiologists to misdiagnose acute appendicitis in children.

MATERIALS AND METHODS

From 2007 to 2013, 374 children operated for suspected appendicitis were proved to either have acute appendicitis (n = 348) or to be negative for appendicitis (n = 26) on pathological reports. Negative appendectomy rates were compared among imaging modalities, age groups and genders. We retrospectively reviewed US and CT findings from negative appendectomy cases.

RESULTS

The overall negative appendectomy rate was 7.0% (26/374). There were no statistically significant differences among the subgroups. The most common misleading presentations on US were sonographic tenderness (9/16, 56%) and non-compressibility (9/16, 56%). The most common misleading finding on CT were the presence of an appendicolith or hyperdense feces (5/12, 42%). Periappendiceal fat inflammation was observed in only one case of negative appendicitis on US and on CT.

CONCLUSION

Radiologists can misdiagnose children with equivocal diameters of appendices as having acute appendicitis when sonographic tenderness or non-compressibility is present on US and when an appendicolith or hyperdense feces is noted on CT. The possibility of negative appendicitis should be borne in mind when periappendiceal fat inflammation is absent or minimal in indeterminate cases.

Histopathological findings in appendectomy specimens: a study of 24,697 cases

PURPOSE

Appendicitis is by far the commonest major emergency general surgical operation. Histopathological examination of the appendix is routinely performed.

METHODS

This study is a retrospective analysis of 24,697 appendectomies performed from January 2003 to December 2011. Pathological reports were analyzed for the following parameters: age, gender, and pathological diagnosis.

RESULTS

Appendectomy specimens represent 17 % of all pathological reports. Acute appendicitis was present in 19,637 (79.5 %) patients. The perforation rate was 6.3 % and was significantly higher in adult patients. The negative appendectomy rate was 15 % and was significantly higher in female and adult patients. The incidence of negative appendectomies had clearly decreased over the 9-year period distribution. Incidental unexpected pathological diagnoses were noted in 226 (0.9 %) appendectomy specimens. Neoplastic lesions were present in 171 cases (0.7 %); they include carcinoid, adenocarcinoma, and mucinous neoplasms.

CONCLUSIONS

Routine pathological examination of appendectomy specimens is expensive. With advances in technology and imaging modalities, the diagnosis of acute appendicitis has improved, with a subsequent significant reduction in negative appendectomy. There are still a number of unusual diagnoses found in appendicectomy specimens supporting the continued use of routine histology.

A new adult appendicitis score improves diagnostic accuracy of acute appendicitis--a prospective study

BACKGROUND

The aim of the study was to construct a new scoring system for more accurate diagnostics of acute appendicitis. Applying the new score into clinical practice could reduce the need of potentially harmful diagnostic imaging.

METHODS

This prospective study enrolled 829 adults presenting with clinical suspicion of appendicitis, including 392 (47%) patients with appendicitis. The collected data included clinical findings and symptoms together with laboratory tests (white cell count, neutrophil count and C-reactive protein), and the timing of the onset of symptoms. The score was constructed by logistic regression analysis using multiple imputations for missing values. Performance of the constructed score in patients with complete data (n = 725) was compared with Alvarado score and Appendicitis inflammatory response score.

RESULTS

343 (47%) of patients with complete data had appendicitis. 199 (58%) patients with appendicitis had score value at least 16 and were classified as high probability group with 93% specificity.Patients with score below 11 were classified as low probability of appendicitis. Only 4% of patients with appendicitis had a score below 11, and none of them had complicated appendicitis. In contrast, 207 (54%) of non-appendicitis patients had score below 11. There were no cases with complicated appendicitis in the low probability group. The area under ROC curve was significantly larger with the new score 0.882 (95% CI 0.858-0.906) compared with AUC of Alvarado score 0.790 (0.758-0.823) and Appendicitis inflammatory response score 0.810 (0.779-0.840).

CONCLUSIONS

The new diagnostic score is fast and accurate in categorizing patients with suspected appendicitis, and roughly halves the need of diagnostic imaging.

A simple algorithm reduces computed tomography use in the diagnosis of appendicitis in children

BACKGROUND

A diagnostic algorithm for appendicitis in children was created to reduce computed tomography (CT) use owing to the risk of cancer from radiation exposure and cost of CT. This study evaluates the impact of the algorithm on CT use and diagnostic accuracy of appendicitis.

METHODS

Patients ≤18 years who underwent appendectomy for suspected appendicitis after presenting to the emergency department for 2 years before and 3 years after algorithm implementation were identified. Clinical characteristics and outcomes, including use of CT and negative appendectomy rate, were compared between the pre- and post-implementation periods. Multivariable analysis was used to determine the impact of CT on negative appendectomy.

RESULTS

We identified 331 patients-41% in the pre- and 59% in the post-implementation period. CT utilization decreased from 39% to 18% (P < .001) after implementation. The negative appendectomy rate increased from 9% to 11% (P = .59). Use of CT did not impact the risk of negative appendectomy (P = .64).

CONCLUSION

Utilization of CT was significantly reduced after implementation of a diagnostic algorithm for appendicitis without impacting diagnostic accuracy. Given the concern for increased risk of cancer after CT, these results support use of an algorithm in children with suspected appendicitis.

A simple clinical decision rule to rule out appendicitis in patients with nondiagnostic ultrasound results

OBJECTIVES

The objective was to identify a set of clinical features that can rule out appendicitis in patients with suspected acute appendicitis and nondiagnostic ultrasound (US) results, allowing safe discharge and next-day reevaluation without initial computed tomography (CT) or magnetic resonance imaging (MRI).

METHODS

Data on clinical and US evaluation, including a number of prespecified variables potentially associated with acute appendicitis, were prospectively collected in two diagnostic accuracy studies of imaging. These studies included patients with suspected appendicitis seen in the emergency department (ED). For development and validation of the clinical decision rule (CDR), only patients with inconclusive or negative US results were included. There were 199 (of 422) patients in the development cohorts and 120 (of 211) patients in the validation cohort. Logistic regression analysis was used for data from patients with inconclusive or negative US results, and profiles were created of all possible combinations of predictors retained in the multivariable model. A final diagnosis was assigned by an expert panel based on perioperative data, histopathology, and clinical follow-up of at least 3 months.

RESULTS

The CDR selected patients after negative or inconclusive US for discharge and next-day reevaluation without initial CT or MRI if fewer than two of the following predictors were present: male sex, migration of pain to the right lower quadrant, vomiting, and white blood cell (WBC) count higher than 12.0 × 10(9) /L. Applying the CDR in the development set selected 126 of 199 (63%) patients with negative or inconclusive US results for discharge without further imaging. This rule reduced the probability of appendicitis from 26% (51 of 199) in the total group of patients with negative or inconclusive US results to 12% (15 of 126) in the group that would be discharged based on the rule (p = 0.001). In the validation set (n = 120), the decision rule selected 72 (60%) patients for discharge and next-day reevaluation and reduced the probability of appendicitis from 20% (24 of 120) in the total group to 6% (4 of 72) in the patients selected on the rule (p = 0.001). The negative predictive value of the decision rule in the validation set was 94% (95% confidence interval [CI] = 87% to 98%). In comparison, the negative predictive value of CT in the same group was 99% (95% CI = 93% to 100%, p = 0.14), and that of MRI was 99% (95% CI = 94% to 100%, p = 0.12). Alternative decision rules based on combinations of the present decision rule with C-reactive protein (CRP) results did not improve selection.

CONCLUSIONS

This newly developed CDR significantly reduces the probability of appendicitis in a large subgroup of patients with negative or inconclusive US results. These patients can be safely discharged for outpatient reevaluation without further initial imaging if proper follow-up is available. This could assist in lowering the number of ED imaging investigations in patients with suspected appendicitis.

Ultrasonography/MRI versus CT for diagnosing appendicitis

BACKGROUND

Cross-sectional imaging increases accuracy in diagnosing appendicitis. We hypothesized that a radiation-free imaging pathway of ultrasonography selectively followed by MRI would not change clinical end points compared with computed tomography (CT) for diagnosis of acute appendicitis in children.

METHODS

We retrospectively reviewed children (<18 years old) who had diagnostic imaging for suspected acute appendicitis between November 2008 and October 2012. Before November 2010 CT was used as the primary imaging modality (group A); subsequently, ultrasonography was the primary imaging modality followed by MRI for equivocal findings (group B). Data collected included time from triage to imaging and treatment and results of imaging and pathology.

RESULTS

Six hundred sixty-two patients had imaging for suspected appendicitis (group A = 265; group B = 397, of which 136 [51%] and 161 [41%], respectively, had positive imaging for appendicitis). Negative appendectomy rate was 2.5% for group A and 1.4% for group B. Perforation rate was similar for both groups. Time from triage to antibiotic administration and operation did not differ between groups A and B. There was higher proportion of positive imaging and appendectomies in group A and thus more negative imaging tests in group B (ultrasonography and MRI), but diagnostic accuracy of the 2 imaging pathways was similar.

CONCLUSIONS

In children with suspected acute appendicitis, a radiation-free diagnostic imaging of ultrasonography selectively followed by MRI is feasible and comparable to CT, with no difference in time to antibiotic administration, time to appendectomy, negative appendectomy rate, perforation rate, or length of stay.

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.

Use of white blood cell count and negative appendectomy rate

BACKGROUND

Despite increased utilization of laboratory, radiologic imaging, and scoring systems, negative appendectomy (NA) rates in children remain above 3% nationwide. We reviewed the clinical data of patients undergoing appendectomy to further reduce our NA rate.

METHODS

A retrospective review was conducted of all appendectomies performed for suspected appendicitis at a tertiary children's hospital during a 42-month period. Preoperative clinical, laboratory, and radiographic data were collected. Variables absent or normal in more than half of NAs were further analyzed. Receiver operating characteristic curves were constructed for continuous variables by using appropriate cutoff points to determine sensitivity and false-positive rates. The results were validated by analyzing the 12 months immediately after the establishment of these rules.

RESULTS

Of 847 appendectomies performed, 22 (2.6%) had a pathologically normal appendix. The only variables found to be normal in more than half of NAs were white blood cell (WBC) count (89%) and neutrophil count (79%). A receiver operating characteristic curve indicates that using WBC cutoffs of 9000 and 8000 per µL yielded sensitivities of 92% and 95%, respectively, and reduction in NA rates by 77% and 36%, respectively. Results observed in the subsequent 12 months confirmed these expected sensitivities and specificities.

CONCLUSIONS

Absence of an elevated WBC count is a risk factor for NA. Withholding appendectomy for WBC counts <9000 and 8000 per µL reduces the NA rate to 0.6% and 1.2%, respectively. Missed true appendicitis in patients with normal WBC counts can be mitigated by a trial of observation in those presenting with early symptom onset.

Alvarado, Eskelinen, Ohhmann and Raja Isteri Pengiran Anak Saleha Appendicitis scores for diagnosis of acute appendicitis

AIM: To assess the reliability and practical applicability of the widely used Alvarado, Eskelinen, Ohhmann and Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA) scoring systems in patients with suspected acute appendicitis.

METHODS: Patients admitted to our tertiary center due to suspected acute appendicitis constituted the study group. Patients were divided into two groups. appendicitis group (Group A) consisted of patients who underwent appendectomy and were histopathologically diagnosed with acute appendicitis, and non-appendicitis group (Group N-A) consisted of patients who underwent negative appendectomy and were diagnosed with pathologies other than appendicitis and patients that were followed non-operatively. The operative findings for the patients, the additional analyses from follow up of the patients and the results of those analyses were recorded using the follow-up forms.

RESULTS: One hundred and thirteen patients with suspected acute appendicitis were included in the study. Of the 113 patients (62 males, 51 females), the mean age was 30.2 ± 10.1 (range 18-67) years. Of the 113 patients, 94 patients underwent surgery, while the rest were followed non-operatively. Of the 94 patients, 77 patients were histopathologically diagnosed with acute appendicitis. Our study showed a sensitivity level of 81% for the Alvarado system when a cut-off value of 6.5 was used, a sensitivity level of 83.1% for the Ohmann system when a cut-off value of 13.75 was used, a sensitivity level of 80.5% for the Eskelinen system when a cut-off value of 63.72 was used, and a sensitivity level of 83.1% for the RIPASA system when a cut-off value of 10.25 was used.

CONCLUSION: The Ohmann and RIPASA scoring systems had the highest specificity for the diagnosis of acute appendicitis.

CT of acute appendicitis: can diagnostic accuracy serve as a practical performance metric for readers specialized in abdominal imaging?

PURPOSE

To investigate diagnostic accuracy for acute appendicitis at computed tomography (CT) as a performance metric for radiologists specialized in abdominal imaging.

MATERIALS AND METHODS

We retrospectively identified six attending abdominal imagers who each independently interpreted over 100 CT studies for suspected acute appendicitis.

RESULTS

The mean number of studies per reader was 311 (range, 129-386). Mean reader diagnostic accuracy was 95.0% (range, 91.4-97.1%). Only one had a diagnostic accuracy (91.4%) that was significantly lower than all others.

CONCLUSION

Diagnostic accuracy for acute appendicitis at CT may be an impractical performance metric for radiologists specialized in abdominal imaging.

Can herniation pit of the femoral neck mimic an acute appendicitis? A case report

Although in most cases the diagnosis of acute appendicitis is straightforward, not all patients experience typical symptoms and other conditions may mimic appendicitis. In fact, 15-25% of appendectomies involve the removal of a normal appendix. To date, there is no literature evidence that herniation pit (HP) may mimic acute appendicitis. We report a case of a 30 year old woman admitted to the Emergency Department for severe, acute pain developing a few hours earlier in the lower right fossa, with irradiaton to the right thigh. She did not present any fever, nausea or vomiting, Blumberg's sign was absent but the psoas sign and obturator sign were both positive. WBC count was 16,000/mm3 and the Alvarado score was 4. Biochemistry profile was normal. US was unclear and transvaginal ultrasound did not show any gynecological disease. CT scan showed only an herniation pit of the right femoral neck. The patient was admitted to an orthopedic ward and treated with anti-inflammatory therapy. She was discharged after 2 days without any pain and in good conditions. Our case demonstrates that herniation pits of the right femoral neck should be considered a potential cause of right lower abdominal pain mimicking acute appendicitis, particularly if the psoas sign and obturator sign are positive and the patient is physically active.

Integrating MR imaging into the clinical workup of pregnant patients suspected of having appendicitis is associated with a lower negative laparotomy rate: single-institution study

PURPOSE

To determine if integrating magnetic resonance (MR) imaging into the workup of right lower quadrant pain in pregnant patients was associated with improved outcomes as measured by the negative laparotomy rate (NLR) and the perforation rate (PR).

MATERIALS AND METHODS

Institutional review board approval was obtained for this retrospective review of medical records. Two hundred sixty-seven pregnant patients who underwent either surgery (n = 82) or an MR imaging examination (n = 217) because of suspicion of appendicitis between January 1, 1996, and August 31, 2011, were identified. Relevant ultrasonographic and MR imaging reports were classified as showing true-positive, false-positive, true-negative, false-negative, or equivocal findings. MR imaging utilization was analyzed to define pre- and post-MR imaging cohorts. NLR and PR were calculated for both cohorts and were compared by using a Fisher exact probability test. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for MR imaging were calculated.

RESULTS

MR imaging was introduced into the clinical workup in 2004. From 1996 to 2003, the NLR for pregnant patients was 55% (17 of 31), and the PR was 21% (three of 14). From 2004 to 2011, the NLR was 29% (15 of 51), and the PR was 26% (nine of 35). The 47% decline in the NLR ([55%-29%]/55%) was statistically significant (P = .02). The change in PR was not significant (P > .99). The sensitivity, specificity, PPV, and NPV of MR imaging in the diagnosis of appendicitis were 89% (17 of 19), 97% (187 of 193), 74% (17 of 23), and 99% (187 of 189), respectively.

CONCLUSION

The routine incorporation of MR imaging into the clinical workup for suspicion of appendicitis in pregnant patients at this institution was associated with a decrease in the NLR of 47% without a significant change in the PR.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12121027/-/DC1.

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.

Negative appendicectomy rate as a quality metric in the management of appendicitis: impact of computed tomography, Alvarado score and the definition of negative appendicectomy

INTRODUCTION

The negative appendicectomy rate (NAR) is a quality metric in the management of appendicitis. While computed tomography (CT) has been associated with a low NAR, Alvarado scoring produces an acceptable NAR. The definition of negative appendicectomy may affect the NAR. This study examined the impact of CT, Alvarado score and definition on the NAR.

METHODS

The charts of 1,306 emergency appendicectomy patients from 1996 to 2010 were reviewed. Three five-year cohorts were created (Cohort A: 1996-2000, Cohort B: 2001-2005, Cohort C: 2006-2010) and the NAR was calculated for each cohort using two definitions of negative appendicectomy: absence of inflammation (NAR-STD) and absence of intramural neutrophils (NAR-STR). NAR-STD was correlated to the CT rate for Cohorts B and C and also to Alvarado score for Cohort C.

RESULTS

When the definition of negative appendicectomy was changed, the NAR rose from 9.2% to 15.8% (p=0.0097) for Cohort A, from 2.8% to 8.6% (p=0.0180) for Cohort B (CT rate: 80.6%) and from 3.0% to 6.7% (p=0.0255) for Cohort C (CT rate: 92.4%). The introduction of CT lowered NAR-STD from 1996-2000 (9.2%) to 2001-2010 (2.9%) but increasing the CT rate from 2001-2010 had no impact on the NAR. The positive predictive value for Alvarado score (98.60%) and CT (99.03%) were similar.

CONCLUSIONS

The definition of a negative appendicectomy determines the NAR. CT reduces the NAR regardless of definition but routine CT is unnecessary for male patients with positive Alvarado scores. Early/mild appendicitis may resolve without surgery and CT may contribute to unnecessary surgery. Alvarado scoring allows selective use of CT in suspected appendicitis.

Evaluation of the appendix during diagnostic laparoscopy, the laparoscopic appendicitis score: a pilot study

BACKGROUND

Diagnostic laparoscopy is the ultimate diagnostic tool to evaluate the appendix. Still, according to the literature, this strategy results in a negative appendectomy rate of approximately 12-18 % and associated morbidity. Laparoscopic criteria for determining appendicitis are lacking. The goal of this study is to define clear and reliable criteria for appendicitis during diagnostic laparoscopy that eventually may safely reduce the negative appendectomy rate.

METHODS

From December 2009 through April 2011, 134 patients were included and analysed in a single-centre prospective pilot study. Intraoperatively, the appendix was evaluated by the surgeon according to nine criteria for appendicitis. The operating surgeon decided whether it should be removed or not. Immediately after the operation the surgeon had to complete a questionnaire on nine criteria for appendicitis. All removed appendices were examined by a pathologist. In case the appendix was not removed, the clinical postoperative course was decisive for the (missed) presence of appendicitis.

RESULTS

In 109 cases an inflamed appendix was removed; in 25 patients the appendix was normal, 3 of which had been removed. After univariate analysis and clinical judgement six variables were included in the Laparoscopic APPendicitis score (LAPP score). In this study, use of the LAPP score would have led to a positive predictive value of 99 % and a negative predictive value of 100 %.

CONCLUSIONS

This study presents the LAPP score. The LAPP score is an easily applicable score that can be used by surgeons to evaluate the appendix during diagnostic laparoscopy. The score has high positive and negative predictive value. The LAPP score needs to be validated in a multicentre validation study.

Histological characterization of appendectomy specimens with intraoperative appearance of vascular injection

BACKGROUND

Acute appendicitis frequently needs acute surgical intervention. Laparoscopic appendectomy (LA) and conventional open appendectomy (OA) are well established procedures, but appendectomy for intraoperative inconspicuous or vascular injected appendixes remains under debate because of potential postoperative morbidity. The aim of this study was to correlate intraoperative nonacute appendixes with histological and clinical outcome.

METHODS

Between 2005 and 2009, a total of 1,017 patients underwent OA or LA. A total of 1,005 patients were enrolled with inclusion criteria of suspicious acute appendicitis preoperatively. One hundred twenty-nine of 1,005 patients had intraoperative normal, vascular injected or chronic appendixes that were defined as nonacute appendicitis. Intraoperative findings were correlated with histological results and clinical outcome of patients.

RESULTS

Of 129 (12.8 %) of 1,005 patients with macroscopically nonacute appendicitis intraoperatively, 16.3 % had normal findings, 81.4 % vascular injection, and 2.3 % chronic alterations; and 94.6 % of nonacute appendixes had histopathological alterations: 38.9 % chronic, 14.0 % neurogenic, 26.4 % acute, 13.2 % phlegmonous, and 2.3 % malignant. Coproliths were found in 21.7 % of patients, most in vascular injected appendixes. Four of seven patients with histopathological normal appendixes had coproliths. Morbidity rate was 2.3 %, with no mortality.

CONCLUSIONS

Appendiceal resection for intraoperative nonacute appendixes should be recommended because of high incidence of histopathological findings with low morbidity. In particular, chronic and neurogenous alterations cannot be predicted clinically or verified by radiological examination, but may cause recurrent symptoms.

Evaluation of the appendicitis inflammatory response score for patients with acute appendicitis

BACKGROUND

Acute appendicitis is still a difficult diagnosis. Scoring systems are designed to aid in the clinical assessment of patients with acute appendicitis. The Alvarado score is the most well known and best performing in validation studies. The purpose of the present study was to externally validate a recently developed appendicitis inflammatory response (AIR) score and compare it to the Alvarado score.

METHODS

The present study selected consecutive patients who presented with suspicion of acute appendicitis between 2006 and 2009. Variables necessary to evaluate the scoring systems were registered. The diagnostic performance of the two scores was compared.

RESULTS

The present study included 941 consecutive patients with suspicion of acute appendicitis. There were 410 male patients (44%) and 531 female patients (56%). The area under the receiver operating characteristic curve of the AIR score was 0.96 and significantly better than the area under the curve of 0.82 of the Alvarado score (p < 0.05). The AIR score also outperformed the Alvarado score when analyzing the more difficult patients, including women, children, and the elderly.

CONCLUSIONS

This study externally validates the AIR Score for patients with acute appendicitis. The scoring system has a high discriminating power and outperforms the Alvarado score.

Intraluminal air within an obstructed appendix: a CT sign of perforated or necrotic appendicitis

RATIONALE AND OBJECTIVES

The aim of this study was to evaluate the predictive value of intraluminal air for appendiceal necrosis and/or perforation when not apparent on imaging. Additional factors of intraluminal appendicoliths, age, and gender were also assessed.

MATERIALS AND METHODS

Patients with pathologically proven appendicitis who underwent multidetector computed tomographic imaging over a 3-year period (n = 487) were retrospectively reviewed. Those with imaging evidence for perforation were excluded to create a study population of apparent uncomplicated acute appendicitis (n = 374). Each scan was assessed for intraluminal appendiceal air and appendicoliths on multidetector computed tomography and compared against surgical and pathologic results for appendiceal necrosis and/or perforation.

RESULTS

Image-occult necrosis or perforation was present in 17.4% (65 or 374) of the study cohort. Intraluminal air and appendicoliths were predictive variables by univariate logistic regression (P = .001 and P ≤ .001, respectively), with odds ratios of 2.64 (95% confidence interval, 1.48-4.73) for intraluminal air and 2.67 (95% confidence interval, 1.55-4.61) for appendicoliths. Both remained independent variables on multivariate modeling despite multicollinearity. Increasing age was also predictive (odds ratio, 1.25; 95% confidence interval, 1.09-1.44; P = .002), whereas gender was not (P = .472).

CONCLUSIONS

Intraluminal appendiceal air in the setting of acute appendicitis is a marker of perforated or necrotic appendicitis. Recognition of this finding in otherwise uncomplicated appendicitis at imaging should raise suspicion for image-occult perforation or necrosis.