Differentiation of early perforated from nonperforated appendicitis: MDCT findings, MDCT diagnostic performance, and clinical outcome

Fascial involvement score on unenhanced CT potentially helps predict complicated appendicitis

OBJECTIVES

To assess the accuracy of diagnosing complicated appendicitis by examining changes in the involved fasciae on CT imaging.

METHODS

From January 1, 2020, to December 31, 2023, 273 patients (median age 50 years; range 14-80 years) with surgically and pathologically confirmed appendicitis were analyzed. Of these, 96 had complicated appendicitis and 177 had uncomplicated appendicitis. Fascial involvement score was assessed along with other CT findings and clinical data. Univariate and multivariate logistic regression analyses were conducted to identify potential predictors of complicated appendicitis.

RESULTS

Univariate analysis identified several features significantly associated with complicated appendicitis: age (P < 0.001), gender (P = 0.006), time from symptom onset to diagnosis (P = 0.015), CRP level (P < 0.001), fascial involvement score (P < 0.001), appendiceal diameter (P < 0.001), and the presence of extraluminal air (P < 0.001). Multivariate analysis revealed that the fascial involvement score (odds ratio 2.252; P < 0.001) and appendiceal diameter (odds ratio 1.263; P < 0.001) were independent risk factors for complicated appendicitis. The fascial involvement score demonstrated an area under the receiver operating characteristic curve of 0.896, with a cutoff value of 2.5.

CONCLUSION

Both the fascial involvement score and an appendiceal diameter of 14.5 mm or greater are independent predictors of complicated appendicitis.

Diagnostic Algorithm Based on Machine Learning to Predict Complicated Appendicitis in Children Using CT, Laboratory, and Clinical Features

To establish a diagnostic algorithm for predicting complicated appendicitis in children based on CT and clinical features.

METHODS

This retrospective study included 315 children (<18 years old) who were diagnosed with acute appendicitis and underwent appendectomy between January 2014 and December 2018. A decision tree algorithm was used to identify important features associated with the condition and to develop a diagnostic algorithm for predicting complicated appendicitis, including CT and clinical findings in the development cohort (n = 198). Complicated appendicitis was defined as gangrenous or perforated appendicitis. The diagnostic algorithm was validated using a temporal cohort (n = 117). The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) from the receiver operating characteristic curve analysis were calculated to evaluate the diagnostic performance of the algorithm.

RESULTS

All patients with periappendiceal abscesses, periappendiceal inflammatory masses, and free air on CT were diagnosed with complicated appendicitis. In addition, intraluminal air, transverse diameter of the appendix, and ascites were identified as important CT findings for predicting complicated appendicitis. C-reactive protein (CRP) level, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and body temperature also showed important associations with complicated appendicitis. The AUC, sensitivity, and specificity of the diagnostic algorithm comprising features were 0.91 (95% CI, 0.86-0.95), 91.8% (84.5-96.4), and 90.0% (82.4-95.1) in the development cohort, and 0.7 (0.63-0.84), 85.9% (75.0-93.4), and 58.5% (44.1-71.9) in test cohort, respectively.

CONCLUSION

We propose a diagnostic algorithm based on a decision tree model using CT and clinical findings. This algorithm can be used to differentiate between complicated and noncomplicated appendicitis and to provide an appropriate treatment plan for children with acute appendicitis.

Review of appendicitis: routine, complicated, and mimics

Appendicitis is one of the most common sources of abdominal pain in the emergency setting and is generally considered a straightforward diagnosis. However, atypical appearances, non-visualization, and inconclusive features can make these cases more complicated. The objectives of this article are to review the differential diagnoses for right lower quadrant pain, discuss the imaging characteristics of simple appendicitis on computed tomography (CT), and provide guidance for equivocal cases, complicated appendicitis, and appendicitis mimics. This review will also discuss the identification and management of neoplasms of the appendix.

Conservative antibiotic treatment of pediatric acute uncomplicated appendicitis during the COVID-19 pandemic: a prospective comparative cohort study

BACKGROUND

Our study aimed to compare the clinical outcomes and cost-efficiency of antibiotic management versus laparoscopic appendectomy for acute uncomplicated appendicitis (AUA) in children during the COVID-19 pandemic when resources were limited and transmission risks uncertain.

METHOD

In this prospective comparative cohort study, we analyzed the data of 139 children diagnosed with AUA meeting the following inclusion criteria: 5-18 years of age, symptoms duration of ≤ 48 h, appendix diameter ≤ 11 mm and no appendicolith. Treatment outcomes between non-operative management group (78/139) and upfront laparoscopic appendectomy group (61/139) were compared. Antibiotic regimes were intravenous ceftriaxone/metronidazole or amoxicillin/clavulanic acid for 48 h, followed by oral antibiotics to complete total 10-days course.

RESULTS

8/78 (10.3%) children had early failure (within 48 h) requiring appendectomy. 17/70 (24.3%) patients experienced late recurrence within mean follow-up time of 16.2 ± 4.7 months. There were no statistical differences in peri-operative complications, negative appendicectomy rate, and incidence of perforation and hospitalization duration between antibiotic and surgical treatment groups. Cost per patient in upfront surgical group was significantly higher ($6208.5 ± 5284.0) than antibiotic group ($3588.6 ± 3829.8; p = 0.001).

CONCLUSION

Despite 24.3% risk of recurrence of appendicitis in 16.2 ± 4.7 months, antibiotic therapy for AUA appears to be a safe and cost-effective alternative to upfront appendectomy.

ACR Appropriateness Criteria® Right Lower Quadrant Pain: 2022 Update

This document focuses on imaging in the adult and pregnant populations with right lower quadrant (RLQ) abdominal pain, including patients with fever and leukocytosis. Appendicitis remains the most common surgical pathology responsible for RLQ abdominal pain in the United States. Other causes of RLQ pain include right colonic diverticulitis, ureteral stone, and infectious enterocolitis. Appropriate imaging in the diagnosis of appendicitis has resulted in decreased negative appendectomy rate from as high as 25% to approximately 1% to 3%. Contrast-enhanced CT remains the primary and most appropriate imaging modality to evaluate this patient population. MRI is approaching CT in sensitivity and specificity as this technology becomes more widely available and utilization increases. Unenhanced MRI and ultrasound remain the diagnostic procedures of choice in the pregnant patient. MRI and ultrasound continue to perform best in the hands of the experts. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Evaluation of radiological and temporal characteristics of acute appendicitis on the non-enhanced computed tomography images

PURPOSES

To investigate the relationships and interactions between temporal and radiological features of gangrene and perforation of inflamed appendices.

METHODS

A total of 402 patients were included who underwent laparoscopic appendectomies between January 1, 2016 and March 30, 2020 and had pathologically proved acute appendicitis and preoperative non-enhanced CT examinations. The radiological features (appendix diameter, appendicolith, appendiceal intraluminal gas, periappendiceal gas, periappendiceal fat stranding/fluid, and short axial diameter of the mesenteric lymph nodes) were obtained from the preoperative CT images of 382 patients with visible appendices. Clinical parameters and temporal variables (pre-CT delay, preoperative delay, estimated complication delay, symptom delay, and system delay) were recorded.

RESULTS

Among simple/suppurative, gangrenous, and perforated appendicitis, the radiological characteristics except for short axial diameters of lymph nodes, and the temporal variables other than system delay were significantly different. The Cox regression analysis identified the appendicolith as the independent risk factor for both gangrene and perforation of inflamed appendices by using the preoperative delay or estimated complication delay. By the preoperative delay, the median time for gangrene and perforation was 76.23 (95%CI 73.89-78.58) h and 77.55 (95%CI 74.12-80.98) h, respectively, if appendicolith was present. If estimated complication delay was used as the elapsed time and the appendicolith was perceptible, the median time for gangrene and perforation and was 72.33 (95%CI 62.93-81.74) h and 75.07 (95%CI 69.48-80.65) h, respectively.

CONCLUSION

There were interactions between the time evolution and radiological features of acute appendicitis. The evaluation of gangrene and perforation rate of acute appendicitis could be benefitted from combining the preoperative delay/estimated complication delay with CT characteristics in the preoperative urgent radiological analysis.

The importance of laboratory tests and Body Mass Index in the diagnosis of acute appendicitis

&lt;b&gt;Background:&lt;/b&gt; Acute appendicitis is the most common cause of acute abdomen. Delay in diagnosis increases the mortality and morbidity. &lt;br&gt;&lt;b&gt;Aim: &lt;/b&gt;In this study, we aimed to investigate whether the body mass index is useful in diagnosis and whether the neutrophil /lymphocyte and platelet/lymphocyte ratios can help in determining the inflammation level of acute appendicitis. &lt;br&gt;&lt;b&gt;Meterial and Methods:&lt;/b&gt; Cases of appendectomy performed between June 2012 and December 2018 in our clinic were analyzed retrospectively. Based on the pathology results of the cases included in the study, 4 groups were formed, i.e.: Group 1 (initial stage), Group 2 (catarrhal stage), Group 3 (phlegmonous-gangrenous stage) and Group 4 (perforation). The study compared age, body mass index, leukocyte values, red cell distribution width (RDW), neutrophil/lymphocyte ratio (NLR), platelet /lymphocyte ratio (PLR), and mean platelet volume (MPV) between groups. &lt;br&gt;&lt;b&gt; Results:&lt;/b&gt; 828 cases were included in the study. When compared between groups, the values of Group 3 and Group 4 were higher than those of Group 1 and Group 2 for PLR and NLR. There was no difference in RDW and MPV values in the blood. When Body Mass Index (BMI) was compared between groups, it was found to be significantly higher with increasing histopathological stage. &lt;br&gt;&lt;b&gt;Conclusion:&lt;/b&gt; In acute appendicitis, the blood leukocyte value, elevated PLR and NLR are helpful in diagnosis. We aimed to emphasize that the diagnosis of acute appendicitis is delayed in patients with a BMI above 30 and/or at age of over 40 years, with the perforation rate being determined more frequently.

Predictors for prolonged length of stay after laparoscopic appendectomy for complicated acute appendicitis in adults

BACKGROUND

Appendicitis-related hospitalizations linked with peritonitis or postoperative complications result in longer lengths of stay and higher costs. The aim of the present study was to assess the independent association between potential predictors and prolonged hospitalization after laparoscopic appendectomy (LA) for complicated acute appendicitis (CAA).

METHODS

A retrospective cohort study was conducted on adult patients diagnosed with CAA in which LA was attempted. The primary outcome was a prolonged length of stay (LOS) after surgery, defined as hospitalizations longer than or equal to the 75th percentile for LOS, including the day of discharge. Hierarchical regression models were run to elucidate the independent predictors for the variable of interest.

RESULTS

The present study involved 160 patients with a mean age of 50.71 years. The conversion rate was 1.9%, and the overall postoperative morbidity rate was 23.8%. The median length of stay (LOS) was 5 days (75th percentile: 7 days). Multivariate analyses included nine variables that are statistically and/or clinically relevant to assess its relationship with a prolonged LOS: three preoperative (age, sex, and comorbidity), four intraoperative (appendix gangrene, perforation, degree of peritonitis, and drain placement), and two postoperative (immediate ICU admission and complications). The development of postoperative complications (OR 6.162, 95% CI 2.451-15.493; p = 0.000) and the placement of an abdominal drain (OR 3.438, 95% CI 1.107-10.683; p = 0.033) were found to be independent predictors for prolonged LOS. For patients not presenting postoperative complications, drain placement was the only independent predictor for the outcome (OR 7.853, 95% CI 1.520-40.558; p = 0.014). Sensitivity analyses showed confirmatory results.

CONCLUSION

The intraoperative process of care has a clear impact on LOS after LA for CAA in adults; therefore, the decision of whether to drain in these situations should be made more restrictively yet with judicious caution.

Re-assessing the role of the fecalith in acute appendicitis in adults: case report, case series and literature review

Appendicitis in adults is thought to occur because of luminal obstruction from a fecalith. We present a unique case of a patient who had her entire appendiceal lumen occupied by a fecalith (5.0 cm long) but had no appendicitis. We reviewed the records of 257 veterans who underwent surgical intervention at our institution for the management of acute appendicitis. Fecaliths occurred in 15.6% of patients. At laparotomy, 20.6% had a perforated appendix; pathology showed fecaliths in 20.8% of specimens. A review of the literature inclusive of 25 series showed fecaliths in 33.3% of patients with a normal appendix, 23.5% of patients with acute appendicitis and 24.9% with perforated appendicitis. These data show that appendicitis is not a common cause of fecalith obstruction in adults.

Right hydronephrosis as a sign of complicated appendicitis

OBJECTIVE

Acute appendicitis is known for one of the most common cause of acute abdomen. However, it is still challenging to clearly distinguish complicated from uncomplicated appendicitis preoperatively. We investigated the association between right hydronephrosis and complicated appendicitis compared with other computed tomography (CT) findings of acute appendicitis.

MATERIALS AND METHODS

1275 patients who pathologically diagnosed with acute appendicitis were included. They were classified into the complicated appendicitis and uncomplicated appendicitis groups based on their histopathological results. We reviewed their CT findings, including right hydronephrosis, appendiceal wall defect, periappendiceal abscess, extraluminal or intraluminal free air, appendicolith, appendiceal dilatation, appendiceal wall thickening, periappendiceal infiltration, periappendiceal fluid collection, and ascites. Comparison between the two groups was performed and the diagnostic performance of each CT finding was evaluated. The location of appendix and periureteral extension of periappendiceal infiltration were evaluated in patients with right hydronephrosis.

RESULTS

Out of 1275 patients, 29 (2.3 %) patients showed right hydronephrosis. Right hydronephrosis was significantly related to complicated appendicitis with the odds ratio of 4.90 (95 % confidence interval, 1.62-14.83; P = 0.005). Right hydronephrosis yielded specificity of 99.3 %. All patients with right hydronephrosis accompanied with periappendiceal infiltration and 28 (96.6 %) patients showed periureteral extension. Subcecal and pelvic areas are the most common locations, with 11 (37.9 %) patients each.

CONCLUSION

The presence of right hydronephrosis was specific finding for complicated appendicitis and it could be considered as one of indirect sign of complicated appendicitis.

Sonographic differentiation of complicated from uncomplicated appendicitis

OBJECTIVE

This study aims to differentiate acute uncomplicated and complicated appendicitis, by investigating the correlation between sonographic findings and histological results in different types of paediatric appendicitis.

METHODS

This is a retrospective study of 1017 paediatric patients (age < 18 years) who underwent ultrasound by paediatric radiologists before appendicectomy at our institution between 2006 and 2016. Histologically, uncomplicated appendicitis was primarily associated with transmural infiltration of neutrophil granulocytes, while complicated appendicitis was characterised by transmural myonecrosis. Logistic regression analyses were used to investigate the association between sonographic and histological findings.

RESULTS

Out of 566 (56%) male and 451 (44%) female patients with a mean age of 10.7 years, uncomplicated appendicitis was histologically diagnosed in 446 (44%) children and complicated appendicitis was diagnosed in 348 (34%) cases. The following ultrasound findings were significantly associated with complicated appendicitis in multivariate regression: an increased appendiceal diameter (OR = 1.3, p < .001), periappendiceal fat inflammation (OR = 1.5, p = 0.02), the presence of an appendicolith (OR = 1.7, p = 0.01) and a suspected perforation (OR = 6.0, p < .001) by the pediatric radiologist. For complicated appendicitis, an appendiceal diameter of more than 6 mm had the highest sensitivity (98%), while a sonographically suspected perforation showed the highest specificity (94%).

CONCLUSION

Abdominal sonography by paediatric radiologists can differentiate between uncomplicated and complicated appendicitis in paediatric patients by using an increased appendiceal diameter, periappendiceal fat inflammation, the presence of an appendicolith and a suspected perforation as discriminatory markers.

ADVANCES IN KNOWLEDGE

This paper demonstrates expanded information on ultrasound, which is not only an essential tool for diagnosing appendicitis, but also a key method for distinguishing between different forms of appendicitis when performed by paediatric radiologists. Compared with previous studies, the crucial distinction features in our analysis are 1) the definition of gangrene and not primarily perforation as an acute complicated appendicitis enabling early decision-making by sonography and 2) a large number of patients in a particularly affected age group.

Factors Associated with Complicated Appendicitis: View from a Low-middle Income Country

Introduction Factors associated with complicated appendicitis have been inconsistently identified. Moreover, studies are lacking from low and low-middle countries where access to surgical care is limited. Our objective was to identify factors predicting complicated appendicitis as diagnosed intraoperatively in a low-middle income country hospital. Methodology Retrospective case-control study of patients who underwent laparoscopic appendectomy from 01/2008 to 12/2015 was completed. Based on intraoperative diagnosis of complicated appendicitis, patients were divided into two groups; those with complicated appendicitis (CA) and those who had non-complicated appendicitis (NCA). CT scans were further reviewed to identify presence of appendicolith. Result Of the 442 patients included, 88 (20%) patients were in the CA group while 354 (80%) patients were in the NCA group. Patients in the CA group were older [CA vs. NCA: 34.6 ± 14 vs. 30.4 ± 11.5; p-value < 0.001], had symptoms for longer duration [CA vs. NCA: 2 ± 1.2 vs. 1.5 ± 0.8; p-value: 0.001] and had a greater proportion of patients with appendicoliths [CA vs. NCA: 37 (42%) vs. 84 (23.7%); p-value: 0.001]. On multivariable regression analysis, patients with complicated appendicitis had greater odds of having appendicoliths (OR: 2.4, 95% CI: 1.4-4.07; p-value < 0.001) and symptoms for a longer duration (OR: 1.57, 95% CI: 1.25-1.97; p-value < 0.001). Conclusion Patients with complicated appendicitis had greater odds of having appendicoliths and symptoms for a longer duration. Further studies are warranted in low and low-middle income countries to gauge the impact delay in presentation and intervention has on appendicitis and its outcomes.

Garcia EM, Camacho MA, Karolyi DR, Kim DH, Cash BD, Chang KJ, Feig BW, Fowler KJ, Kambadakone AR, Lambert DL, Levy AD, Marin D, Moreno C, Peterson CM, Scheirey CD, Siegel A, Smith MP, Weinstein S, Carucci LR. ACR Appropriateness Criteria® Right Lower Quadrant Pain-Suspected Appendicitis

Appendicitis remains the most common surgical pathology responsible for right lower quadrant (RLQ) abdominal pain presenting to emergency departments in the United States, where the incidence continues to increase. Appropriate imaging in the diagnosis of appendicitis has resulted in decreased negative appendectomy rate from as high as 25% to approximately 1% to 3%. Contrast-enhanced CT remains the primary and most appropriate imaging modality to evaluate this patient population. MRI is approaching CT in sensitivity and specificity as this technology becomes more widely available and utilization increases. Unenhanced MRI and ultrasound remain the diagnostic procedures of choice in the pregnant patient. MRI and ultrasound continue to perform best in the hands of experts. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Are Preoperative CT Findings Useful for Predicting Postoperative Intraabdominal Abscess in the Patients with Acute Appendicitis?

Background and objective: In patients with acute appendicitis (AA), preoperative computed tomography (CT) findings suggesting development of intraabdominal abscess (IAA) had not been widely used. The aim of this study was to investigate the preoperative clinical and radiological factors that predict the development of a postoperative IAA in patients with AA who were treated by laparoscopic appendectomy (LA). Methods: Two hundred and sixteen patients with pathologically proven AA underwent LA between January 2013 and March 2018 in our department. Medical records and preoperative CT images of these 216 patients were retrospectively reviewed and the predictive factors of postoperative IAA were investigated. In addition, patients were divided into complicated appendicitis (CA) and simple appendicitis (SA) and perioperative factors of two groups were compared. Results: One hundred and forty-seven patients were diagnosed with CA, while the other 69 patients were diagnosed with SA. Sixteen patients developed postoperative IAA in the CA group, while no patients in the SA group did. The univariate analysis revealed that time from onset to surgery more than 3 days (p = 0.011), the preoperative CT finding of periappendiceal fluid (p = 0.003), abscess (p < 0.001), and free air (p < 0.001), operation time more than 120 min (p = 0.023) and placement of a drainage tube (p < 0.001) were significantly associated with the development of IAA. Multivariate analysis revealed that the preoperative CT finding of free air was independently associated with the development of IAA (p = 0.007, odds ratio = 5.427, 95% CI: 1.586⁻18.57). Conclusions: IAA developed predominantly in patients with CA. Preoperative CT findings of free air was found to be an independent predictor for the development of IAA. Surgeons should be meticulous in managing the postoperative course of patients with this finding.

Accuracy of Computed Tomography in Differentiating Perforated from Nonperforated Appendicitis, Taking Histopathology as the Gold Standard

Introduction Acute appendicitis is one of the more common causes of acute abdominal pain. It occurs when the lumen of the appendix is obstructed, leading to inflammation and finally perforation. The preoperative differentiation of perforated from nonperforated appendicitis is important and helpful to define prognosis and determine an adequate therapeutic approach, including consideration for nonsurgical treatment. This study recommends computed tomography (CT), a noninvasive method of investigation, be used frequently in clinically suspected cases of perforated appendicitis in the Pakistani population for better patient outcomes. Objective To determine the diagnostic accuracy of CT in differentiating perforated from nonperforated appendicitis by using histopathology as the gold standard. Material and methods A total of 236 patients with a clinical suspicion of appendicitis were included in this study. CT was performed in Liaquat National Hospital and Medical College. At the time of scanning, intravenous contrast was administered. Histopathology was used as the diagnostic gold standard. CT findings were documented using a proforma. The patient was returned to the referring department and followed after surgery for histopathology. Results Sensitivity, specificity, and positive and negative predictive values, as well as the accuracy of CT in the detection of perforated appendicitis, was 71.4%, 90.7%, 62.5%, 93.6%, and 87.3%, respectively. Conclusion CT findings can be used to select patients with perforated appendicitis for initial nonoperative management.

Comprehensive review of typical and atypical pathology of the appendix on CT: cases with clinical implications

Acute appendicitis is the most common abdominal surgical emergency in the United States with approximately 250,000 cases annually. Computed Tomography (CT) has emerged as the most accurate diagnostic test to triage these patients for emergent surgery. Although the radiology search pattern is prioritized to detect an inflamed appendix, not all appearances equate to a typical surgical appendicitis. There are a select set of atypical pathologies involving the appendix that have subtle differences on CT, but can have catastrophic complications if treated with emergent appendectomy. This paper will review the spectrum of CT appearances and clinical management for typical and atypical appendiceal pathologies.

Diagnostic prediction of complicated appendicitis by combined clinical and radiological appendicitis severity index (APSI)

OBJECTIVES

To develop a routinely applicable severity index for the management of acute appendicitis in adults using combined clinical and radiological parameters and retroperitoneal space planes (RSP).

METHODS

Two hundred consecutive patients with histologically proven acute appendicitis and available presurgical CT scans were analysed retrospectively. Two radiologists assessed all CT scans for morphologic sings of appendicitis and six RSP. Clinical parameters were age, body temperature, C-reactive protein (CRP), white blood cell count, and duration of symptoms. Radiological parameters were appendix diameter and wall thickness, periappendiceal fat stranding and fluid, intraluminal and extraluminal air, thinning of appendiceal wall, caecal wall thickening, appendicolith and abscess formation.

RESULTS

One hundred and three patients (51%) had histologically proven complicated appendicitis. Based on three clinical (age ≥52 years, body temperature ≥37.5°C, duration of symptoms ≥48 h) and four computed tomography (CT) findings (appendix diameter ≥14 mm, presence of periappendiceal fluid, extraluminal air, perityphlitic abscess), the APSI was developed using regression coefficients of multivariate logistic regression analyses with a maximum of 10 points. A score of ≥4 points predicted complicated appendicitis with a positive predictive value of 92% and a negative predictive value of 83%. Substantial to excellent interobserver agreement was found for the four radiological parameters of the APSI [intraclass correlation coefficient (ICC), 0.78-0.83]. The RSP evaluation presented no added value for the diagnosis of complicated appendicitis.

CONCLUSIONS

Using APSI, an accurate and simple prediction of complicated appendicitis in adults was possible. The RSP count was not useful for the diagnosis of complicated appendicitis.

KEY POINTS

• Appendicitis severity score provides an accurate and simple prediction of complicated appendicitis • Appendicitis severity score ≥4 accurately predicted complicated appendicitis (PPV 92%;NPV 83%) • Evaluation of retroperitoneal space planes was not useful in diagnosing complicated appendicitis.

Systematic Review and Meta-Analysis of CT Features for Differentiating Complicated and Uncomplicated Appendicitis

Purpose To perform a systematic review and meta-analysis to identify computed tomographic (CT) features for differentiating complicated appendicitis in patients suspected of having appendicitis and to summarize their diagnostic accuracy. Materials and Methods Studies on diagnostic accuracy of CT features for differentiating complicated appendicitis (perforated or gangrenous appendicitis) in patients suspected of having appendicitis were searched in Ovid-MEDLINE, EMBASE, and the Cochrane Library. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Pooled diagnostic accuracy of the CT features was calculated by using a bivariate random effects model. CT features with pooled diagnostic odds ratios with 95% confidence intervals not including 1 were considered as informative. Results Twenty-three studies were included, and 184 overlapping descriptors for various CT findings were subsumed under 14 features. Of these, 10 features were informative for complicated appendicitis. There was a general tendency for these features to show relatively high specificity but low sensitivity. Extraluminal appendicolith, abscess, appendiceal wall enhancement defect, extraluminal air, ileus, periappendiceal fluid collection, ascites, intraluminal air, and intraluminal appendicolith showed pooled specificity greater than 70% (range, 74%-100%), but sensitivity was limited (range, 14%-59%). Periappendiceal fat stranding was the only feature that showed high sensitivity (94%; 95% confidence interval: 86%, 98%) but low specificity (40%; 95% confidence interval, 23%, 60%). Conclusion Ten informative CT features for differentiating complicated appendicitis were identified in this study, nine of which showed high specificity, but low sensitivity. ^© RSNA, 2017 Online supplemental material is available for this article.

Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging

BACKGROUND

The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated.

OBJECTIVE

To assess the performance of MRI in differentiating perforated from non-perforated appendicitis.

MATERIALS AND METHODS

A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected.

RESULTS

Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%.

CONCLUSION

Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between perforated and non-perforated cases. These results may help guide management decisions as MRI assumes a greater role in the work-up of pediatric appendicitis.

Meaningful standard of reference for appendiceal perforation: pathology, surgery, or both?

Purpose

This retrospective study was aimed to determine if appendiceal perforation identified pathologically but not surgically is clinically meaningful.

Methods

The study consists of 2 parts. First, we reviewed 74 studies addressing appendiceal perforation published in 2012 and 2013. Second, in a cross-sectional study, we classified 1,438 adolescents and adults (mean age, 29.3 ± 8.4 years; 785 men) with confirmed appendicitis as “nonperforation” (n = 1,083, group 1), “pathologically-identified perforation” (n = 55, group 2), “surgically-identified perforation” (n = 202, group 3), or “pathologically- and surgically-identified perforation” (n = 98, group 4). The 4 groups were compared for the frequency of laparoscopic appendectomy and the length of hospital stay using multivariable logistic regression analyses.

Results

The reference standard for appendiceal perforation was frequently missing or inconsistent in the previous studies. Laparoscopic appendectomies were less frequent in groups 3 (52.5%, P = 0.001) and 4 (65%, P = 0.040) than in group 1 (70.7%), while group 2 (73%, P = 0.125) did not significantly differ from group 1. Median hospital stays were 2.9, 3.0, 5.1, and 6.0 days for groups 1–4, respectively. Prolonged hospital stay (≥3.7 days) was more frequent in groups 3 (77.7%, P < 0.001) and 4 (89%, P < 0.001) than in group 1 (23.4%), while group 2 (35%, P = 0.070) did not significantly differ from group 1.

Conclusion

We recommend using surgical rather than pathologic findings as the reference standard for the presence of appendiceal perforation in future investigations.

Impact of high-grade obstruction on outcomes in patients with appendiceal inflammatory masses managed by nonoperative treatment

Purpose

To retrospectively assess the impact of high-grade obstructions identified on initial CT on outcomes of patients with appendiceal inflammatory masses managed by nonoperative treatment.

Methods

Institutional Review Boards approved this retrospective study and informed consent was waived. Included were 52 consecutive patients diagnosed with appendiceal inflammatory masses by CT scan and managed by nonoperative treatment. The main outcome measure was treatment failure and secondary outcomes were complications and initial and total hospital stay. Patient demographics, inflammatory markers, and CT findings for presence of an appendiceal inflammatory mass and high-grade obstruction were assessed. Patients with and without high-grade obstruction were compared for patient characteristics and outcomes using Fisher exact test and Student t-test.

Results

Among 52 patients, 14 (27%) had high-grade obstruction on CT examination at presentation. No significant differences were observed in patient characteristics (P > 0.05), treatment failure (P = 0.33), complications (P = 0.29), or initial (P = 0.73) or total (P = 0.72) hospitalization between patients with and without high-grade obstruction.

Conclusion

For patients who were managed by nonoperative treatment for appendiceal inflammatory masses, the presence of high-grade obstruction identified on initial CT scan did not significantly affect outcomes of treatment failure, complications, and initial and total hospitalization.

Predictors of a histopathologic diagnosis of complicated appendicitis

BACKGROUND

Despite its utilization, the intraoperative (IO) assessment of complicated appendicitis (CA) is subjective. The histopathologic (HP) diagnosis should be the gold standard in identifying patients with CA; however, it is not immediately available to guide postoperative management. The objective of this study was to identify predictors of an HP diagnosis of CA.

MATERIALS AND METHODS

A retrospective review of all patients who underwent appendectomy at our institution from 2011-2013 was conducted. CA was defined by perforation or abscess on pathology report. Predictors of an HP diagnosis of CA were evaluated using a multivariable regression model.

RESULTS

A total of 239 of 1066 patients had CA based on IO assessment, whereas 143 of 239 patients (60%) had CA on HP and IO assessment. On multivariable analysis, an IO diagnosis of CA was associated with an HP diagnosis of CA (odds ratio [OR]: 10.92; 95% confidence interval [CI]: 7.19-16.58). Other risk factors were age (OR: 1.28; 95% CI: 1.09-1.49), number of days of pain (OR: 1.20; 95% CI: 1.07-1.37), increased heart rate (OR: 1.14; 95% CI: 1.02-1.26), appendix size (OR: 1.09; 95% CI: 1.03-1.16), and an appendicolith (OR: 1.74; 95% CI: 1.12-2.71) on preoperative CT imaging.

CONCLUSIONS

In addition to age, increased heart rate, pain duration, appendix size and appendicolith, the IO assessment is also associated with an HP diagnosis of CA; however, 40% of patients were incorrectly classified. Using these predictors with improved IO grading may achieve more accurate diagnosis of CA.

Use of Computed Tomography to Determine Perforation in Patients With Acute Appendicitis

PURPOSE

Urgent appendectomy has long been the standard of care for acute appendicitis. Six randomized trials have demonstrated that antibiotics can safely treat appendicitis, but approximately 1 in 4 of these patients eventually requires appendectomy. Overall treatment success may be limited by complex disease including perforation. Patients׳ success on antibiotic therapy may depend on preoperative identification of complex disease on imaging. However, the effectiveness of computed tomography (CT) in differentiating complex disease including perforated from nonperforated appendicitis remains to be determined. The purpose of this study was to assess the preoperative diagnostic accuracy of CT in determining appendiceal perforation in patients operated for acute appendicitis.

METHODS

We performed a retrospective review of pathology and radiology reports from consecutive patients who presented to the emergency department with suspicion for acute appendicitis between January 2012 and May 2015. CT scans were re-reviewed by abdominal imaging fellowship-trained radiologists using standardized criteria, and the radiologists were blinded to pathology and surgical findings. Radiologists specifically noted presence or absence of periappendiceal gas, abscess, appendicolith, fat stranding, and bowel wall thickening. The overall radiologic impression as well as these specific imaging findings was compared to results of pathology and operative reports. Pathology reports were considered the standard for diagnostic accuracy.

RESULTS

Eighty-nine patients (65% male, average age of 34 years) presenting with right lower quadrant pain underwent CT imaging and prompt appendectomy. Final pathology reported perforation in 48% (n = 43) of cases. Radiologic diagnosis of perforation was reported in 9% (n = 8), correctly identifying perforation in 37.5% (n = 3), and incorrectly reporting perforation in 62.5% of nonperforated cases per pathology. Radiology missed 93% (n = 40) of perforations postoperatively diagnosed by pathology. There was no secondary finding (fat stranding, diameter >13mm, abscess, cecal wall thickening, periappendiceal gas, simple fluid collection, appendicolith, and phlegmon) with a clinically reliable sensitivity or specificity to predict perforated appendicitis. Surgeon׳s report of perforation was consistent with the pathology report of perforation in only 28% of cases.

CONCLUSIONS

The usefulness of a CT for determining perforation in acute appendicitis is limited, and methods to improve precision in identifying patients with complicated appendicitis should be explored as this may help for improving risk prediction for failure of treatment with antibiotic therapy and help guide patients and providers in shared decision-making for treatment options.

Independent Preoperative Predictors of Prolonged Length of Stay after Laparoscopic Appendectomy in Patients over 30 Years of Age: Experience from a Single Institution

Prompt discharge after laparoscopic appendectomy (LA) is a marker of quality of care, fiscally desirable and feasible in select patients. Patients over 30 comprise a more heterogeneous cohort known to experience worse outcomes after LA. We aimed to identify easily available preoperative risk factors portending a postoperative length of stay ≥2 days among patients above age 30. In this investigation, 296 included patients from a single institution who underwent LA for acute appendicitis from 2010 to 2014 were retrospectively reviewed for preoperative demographics, laboratory studies, comorbidities, presentation characteristics, radiographic finding, and other rationally selected factors for association with postoperative length of stay ≥2 days. Bivariate and multivariate analysis was conducted to determine independent risk factors, which were subsequently modeled via receiver-operating characteristic curve generation and Kaplan-Meier analysis. “Classic” presentation [odds ratio (OR) = 0.5, P = .02], elevated red cell distribution width (RDW; OR = 1.5/% increase, P = 0.004) as well as evidence of rupture on CT (OR = 6.9, P < 0.001) were independently associated with postoperative length of stay ≥ 2 days. Modeling length of stay using these factors generated an area under the curve of 0.713 ± 0.037. Kaplan-Meier analysis of “classic” presentation, elevated RDW, and evidence of rupture on CT through the fifth postoperative day generated log-rank P values of 0.02, 0.05, and ≤ 0.001, respectively. In summary, lack of “classic” presentation, elevated RDW, and CT evidence of rupture are novel risk factors for prolonged postoperative length of stay in LA patients over 30. These findings may help target patients most appropriate for prompt discharge.

Contribution of diffusion-weighted MR imaging in follow-up of inflammatory appendiceal mass: Preliminary results and review of the literature

Objective

We aimed to search the contribution of diffusion-weighted imaging (DWI) in follow-up of patients with acute appendicitis associated inflammatory appendiceal mass (IAM). DWI was used as a monitoring imaging method to assess the response of medical treatment.

Materials and methods

19 patients (mean age, 37+–13.1; age range, 19–69; M/F: 10/9), presented with clinical, laboratory and computed tomography (CT) findings suggestive of IAM were enrolled prospectively in this study. CT and DWI images were evaluated by two radiologists in consensus. b values 0, 500 and 1000 s/mm² were used, and DWI images were analysed both qualitatively and quantitatively. Laboratory parameters were C-reactive protein value and white blood cell count. During follow-up changes in the diameter of IMA and laboratory parameters were correlated with ADC values. Conservative treatment with interval appendectomy and a total conservative approach without surgery were the treatment options during follow-up.

Results

We found statistically significant correlation between the ADC values, maximum IAM diameter and laboratory parameters. During follow-up five surgical procedures were performed: one patient underwent surgery for cecal adenocarcinoma and four underwent interval appendectomy. One patient developed acute relapse of IAM at the sixth month of follow-up.

Conclusion

DWI may be used with a significant success for follow-up of patients with IAM. As a monitoring imaging method, DWI may also aid in determining of most appropriate timing for interval appendectomy as well as may help in diagnosing alternative diagnoses (e.g. malignancy and inflammatory bowel disease) that can mimic IAM.

Pre-operative CT predictors associated with 30-day adverse events in patients with appendiceal inflammatory masses who underwent immediate appendectomies

PURPOSE

To retrospectively evaluate pre-operative CT predictors that are associated with 30-day adverse events in patients who underwent immediate appendectomies for appendiceal inflammatory masses.

METHODS

This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. One hundred forty-four consecutive patients who underwent immediate appendectomies and were diagnosed with appendiceal inflammatory masses by pre-operative CT from January 2005 to December 2013 at a tertiary hospital were included. The main outcome measure was 30-day adverse events. Patient demographics and data for inflammatory markers including leukocyte counts, segmented neutrophils, and C-reactive protein levels were collected by a single radiologist. Pre- and post-operative CT findings were evaluated for features of appendiceal inflammatory masses, associated findings, and post-operative adverse events by two radiologists in a blinded fashion with consensus to assess surgical and pathologic results, post-operative outcomes, and original CT interpretations. Appendiceal inflammatory masses were defined as complicated appendicitis with a phlegmon or an abscess that was identified on pre-operative CT exam. Factors associated with 30-day adverse events were assessed using logistic regression analysis.

RESULTS

A total of 22 (15%) of the 144 patients (mean age [±SD] 44.6 ± 22.0 years, range 3-97 years) experienced 30-day adverse events: ten intra-abdominal abscesses, three wound infections, two cases of peritonitis, two small bowel obstructions, two intra-abdominal abscesses with peritonitis, one intra-abdominal abscess with wound infection, one intra-abdominal abscess with small bowel obstruction, and one case of peritonitis with small bowel obstruction. In univariate analysis, the presence of appendicolith (odds ratio [OR] 2.49, p = 0.048) and high-grade obstruction (OR 3.79; p = 0.01) were associated with adverse events. High-grade obstruction (adjusted OR 3.05; p = 0.04) was the only independent pre-operative predictor associated with 30-day adverse events in patients with appendiceal inflammatory masses.

CONCLUSIONS

High-grade obstruction was an independent pre-operative CT predictor associated with 30-day adverse events in patients who underwent immediate appendectomies for appendiceal inflammatory masses.

International normalized ratio and serum C-reactive protein are feasible markers to predict complicated appendicitis

BACKGROUND

Diagnostic approach for complicated appendicitis is still controversial. We planned this study to analyze preoperative laboratory markers that may predict complications of appendicitis.

METHODS

Patients who underwent appendectomy were retrospectively recruited. They were divided into complicated appendicitis and non-complicated appendicitis groups and their preoperative laboratory results were reviewed.

RESULTS

A total of 234 patients were included. Elevated international normalized ratio (INR) and serum C-reactive protein (CRP) were associated with complicated appendicitis (p = 0.001). On ROC curve analysis, area under the curve (AUC) of CRP and INR were 0.796 and 0.723, respectively.

CONCLUSIONS

INR and CRP increased significantly in patients with complicated appendicitis. Further studies evaluating INR and CRP in patients undergoing conservative management for appendicitis are required.

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.

High failure rate of nonoperative management of acute appendicitis with an appendicolith in children

BACKGROUND

The purpose of this study was to investigate the feasibility of nonoperative management of acute appendicitis in children with an appendicolith identified on preoperative imaging.

STUDY DESIGN

We performed a prospective nonrandomized trial of nonoperative management of uncomplicated acute appendicitis with an appendicolith in children aged 7 to 17years. The primary outcome was the failure rate of nonoperative management, defined as having undergone an appendectomy. Early termination was set to occur if the lower limit of the 95% confidence interval of the failure rate was greater than 20% at 30days or 30% at 1year.

RESULTS

Recruitment for this study was halted after enrollment of 14 patients (N=5 nonoperative; N=9 surgery). The failure rate of nonoperative management was 60% (3/5) at a median follow-up of 4.7months (IQR 1.0-7.6) with a 95% CI of 23%-88%. None of the three patients that failed nonoperative management had complicated appendicitis at the time of appendectomy, while six out of nine patients who chose surgery had complicated appendicitis (0/3 vs. 6/9, p=0.18). The trial was stopped for concerns over patient safety.

CONCLUSIONS

Nonoperative management of acute appendicitis with an appendicolith in children resulted in an unacceptably high failure rate.

Multimodality approach for imaging of non-traumatic acute abdominal emergencies

"Acute abdomen" includes spectrum of medical and surgical conditions ranging from a less severe to life-threatening conditions in a patient presenting with severe abdominal pain that develops over a period of hours. Accurate and rapid diagnosis of these conditions helps in reducing related complications. Clinical assessment is often difficult due to availability of over-the-counter analgesics, leading to less specific physical findings. The key clinical decision is to determine whether surgical intervention is required. Laboratory and conventional radiographic findings are often non-specific. Thus, cross-sectional imaging plays a pivotal role for helping direct management of acute abdomen. Computed tomography is the primary imaging modality used for these cases due to fast image acquisition, although US is more specific for conditions such as acute cholecystitis. Magnetic resonance imaging or ultrasound is very helpful in patients who are particularly sensitive to radiation exposure, such as pregnant women and pediatric patients. In addition, MRI is an excellent problem-solving modality in certain conditions such as assessment for choledocholithiasis in patients with right upper quadrant pain. In this review, we discuss a multimodality approach for the usual causes of non-traumatic acute abdomen including acute appendicitis, diverticulitis, cholecystitis, and small bowel obstruction. A brief review of other relatively less frequent but important causes of acute abdomen, such as perforated viscus and bowel ischemia, is also included.