Introduction of appendiceal CT: impact on negative appendectomy and appendiceal perforation rates

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.

Pitfalls and mimickers at 64-section helical CT that cause negative appendectomy: an analysis from 1057 appendectomies

PURPOSE

To determine the rate of negative appendectomy and clarify the causes of negative appendectomy in patients with clinically suspected acute appendicitis who had surgery after 64-section helical computed tomography (CT).

MATERIAL AND METHODS

A retrospective analysis of 1057 patients who had appendectomy after 64-section helical CT was performed to determine the rate of negative appendectomy. The 64-section helical CT examinations obtained with submillimeter and isotropic voxels in the patients with negative appendectomy were analyzed by two readers and compared to clinical, operative and histopathological reports, discharge summaries and original radiology reports.

RESULTS

The negative appendectomy rate was 1.7% (18/1057). Appendix enlargement (>6 mm) and fat stranding were present in 17 (17/18; 94%) and 6 patients (6/18; 33%), respectively. In 13 patients (13/18; 72%) 64-section helical CT findings were consistent with acute appendicitis. Interpretive errors in original imaging reports were identified in five patients (5/18; 28%).

CONCLUSION

The preoperative use of 64-section helical CT results in a very low rate of negative appendectomy. Patients with negative appendectomy have 64-section helical CT findings consistent with a diagnosis of acute appendicitis in the majority of cases. Interpretive errors are less frequent.

State of the art: emergency department observation units

Hospitals and emergency departments face the challenges of escalating healthcare costs, mismatched resource utilization, concern over avoidable admissions, and hospital and emergency department overcrowding. One approach that has been used by hospitals to address these issues is the use of emergency department observation units. Research in this setting has increased in recent years, leading to a better understanding of the role of these units and their unique benefits. These benefits have been proven for health systems as a whole and for several acute conditions including chest pain, asthma, syncope, transient ischemic attack, atrial fibrillation, heart failure, abdominal pain, and more. Benefits include a decrease in diagnostic uncertainty, lower cost and resource utilization, improved patient satisfaction, and clinical outcomes that are comparable to admitted patients. As more hospitals begin to use observation units, there is a need for further education and research in how to optimize the use of emergency department observation units. The purpose of this article is to provide a general overview of observation units, including advancements and research in this field.

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.

Do you need a computed tomographic scan to evaluate suspected appendicitis in young men: an administrative database review

BACKGROUND

The purpose of this study was to evaluate the impact of computed tomographic (CT) scans of the abdomen on clinical outcomes and costs in young male patients presenting with suspected appendicitis.

METHODS

Discharge data from the University HealthSystem Consortium was accessed for all male patients between 18 and 55 years of age from October 2007 to June 2011.

RESULTS

Of a total of 13,228 patients who met the inclusion criteria, 11,340 (85%) were assessed using a CT scan of the abdomen, whereas 1,888 (15%) did not undergo CT evaluation. Patients undergoing CT imaging compared with those without a CT scan had less morbidity (.86% vs 2.2%, P < .0001) and fewer 30-day readmissions (1.8% vs 5.13%, P < .0001). However, CT imaging resulted in a higher overall length of hospital stay and a higher total cost.

CONCLUSIONS

This study suggests that in young men with suspected appendicitis, the use of an abdominal CT scan is associated with improved immediate postoperative complications, lower readmission rates with observed higher length of stay, and increased cost of care.

Pathologies of the appendix: a 10-year review of 4670 appendicectomy specimens

BACKGROUND

Debate surrounds the management of the macroscopically normal appendix. Current literature recommends its removal given the high incidence of microscopic appendicitis, and other unusual pathologies in the normal-looking appendix. Negative appendicectomies are reported on the decline with increased use of diagnostic radiological adjuncts.

METHODS

This study analysed pathologies of the appendix over 10 years in the Pathology Department in Canberra. A positive appendicectomy was defined as acute appendicitis, faecoliths, worms, endometriosis or appendiceal tumours. We reviewed the positive appendicectomy rate over this time period.

RESULTS

There were 4670 appendicectomy specimens in 2386 males (51.1%) and 2284 (49%) females. The incidence of acute appendicitis was 71.3% and the positive appendicectomy rate was 76.3%. There were significantly fewer negative appendicectomies in males (16.8%) compared with females (31.0%). There was no appreciable change in this trend over the study period. Of the positive appendicectomies, there were 129 (3.6%) faecoliths. Of these, only 39.5% had concomitant appendicitis. There were 44 (1.2%) specimens identified with worms. Of these, 40.9% had concomitant appendicitis. There were 14 cases of endometriosis of the appendix of which 36% had concomitant appendicitis. There were 58/3562 (1.6%) appendiceal tumours within the positive appendicectomy group the majority of which were carcinoid tumours (65.5%).

CONCLUSION

There is a higher incidence of negative appendicectomies in women compared with men, which is similar to other published studies. Faecoliths and worms are a known cause of appendiceal colic and in our series were identified mostly in the absence of histological evidence of appendicitis.

The effect of abdominal pain duration on the accuracy of diagnostic imaging for pediatric appendicitis

STUDY OBJECTIVE

Advanced imaging with computed tomography (CT) or ultrasonography is frequently used to evaluate for appendicitis. The duration of the abdominal pain may be related to the stage of disease and therefore the interpretability of radiologic studies. Here, we investigate the influence of the duration of pain on the diagnostic accuracy of advanced imaging in children being evaluated for acute appendicitis.

METHODS

A secondary analysis of a prospective multicenter observational cohort of children aged 3 to 18 years with suspected appendicitis who underwent CT or ultrasonography was studied. Outcome was based on histopathology or telephone follow-up. Treating physicians recorded the duration of pain. Imaging was coded as positive, negative, or equivocal according to an attending radiologist's interpretation.

RESULTS

A total of 1,810 children were analyzed (49% boys, mean age 10.9 years [SD 3.8 years]); 1,216 (68%) were assessed by CT and 832 (46%) by ultrasonography (238 [13%] had both). The sensitivity of ultrasonography increased linearly with increasing pain duration (test for trend: odds ratio=1.39; 95% confidence interval 1.14 to 1.71). There was no association between the sensitivity of CT or specificity of either modality with pain duration. The proportion of equivocal CT readings significantly decreased with increasing pain duration (test for trend: odds ratio=0.76; 95% confidence interval 0.65 to 0.90).

CONCLUSION

The sensitivity of ultrasonography for appendicitis improves with a longer duration of abdominal pain, whereas CT demonstrated high sensitivity regardless of pain duration. Additionally, CT results (but not ultrasonographic results) were less likely to be equivocal with longer duration of abdominal pain.

Acute appendicitis within a recurrent inguinal hernia presenting as epididymo-orchitis

We report the first case of appendicitis within a recurrent inguinal hernia, more unique in its presentation as epididymo-orchitis. A 61-year old male presented with right testicular pain, erythematous scrotum and raised inflammatory markers. He previously had recurrent left epididymo-orchitis and right inguinal hernia repair. A diagnosis of epididymo-orchitis was made but CT was performed which diagnosed acute appendicitis within a recurrent inguinal hernia entering the scrotum. This was confirmed intra-operatively with a distal inflamed appendix segment passing beyond the medial border of the exposed mesh. Correct pre-operative CT diagnosis requires high index of suspicion even with innocuous testicular symptoms. CT reduces misdiagnosis which is associated with significant morbidity, and also aids in planning surgical approach. The only other case of acute appendicitis presenting with testicular symptoms was diagnosed only during scrotal exploration necessitating further laparotomy. The appendix entrapment beyond the mesh could suggest an alternative aetiology of mesh-related appendicitis.

Advanced radiologic imaging for pediatric appendicitis, 2005-2009: trends and outcomes

OBJECTIVES

To examine the variability in the use of computed tomography (CT) and ultrasound (US) for children with appendicitis and identify associations with clinical outcomes, and to demonstrate any trends in diagnostic imaging between 2005 and 2009.

STUDY DESIGN

This was a retrospective review of children evaluated for appendicitis in an emergency department between 2005 and 2009 using an administrative database of 40 pediatric institutions in the United States. Imaging utilization by institutions was studied for association with 3 clinical outcomes.

RESULTS

A total of 55 238 children with appendicitis were studied. Utilization of CT and US varied widely across institutions, with medians of 34% (IQR, 21%-49%) for CT and 6% (IQR, 2%-26%) for US. Increased use of US or a combination of CT and US (but not of CT use alone) was associated with a lower negative appendectomy rate. Imaging was not associated with other clinical outcomes. In children with appendicitis, the use of US has increased since 2007, whereas that of CT has decreased.

CONCLUSION

There is considerable variation in the use of CT and US for children with appendicitis at major pediatric institutions. At the institutional level, increased use of US or combined US and CT is associated with a lower negative appendectomy rate. Despite the better diagnostic accuracy of CT compared with US, the use of CT is decreasing.

Diagnostic imaging and negative appendectomy rates in children: effects of age and gender

BACKGROUND AND OBJECTIVES

Diagnostic imaging is often used in the evaluation of children with possible appendicitis. The utility of imaging may vary according to a patient's age and gender. The objectives of this study were (1) to examine the use of computed tomography (CT) and ultrasound for age and gender subgroups of children undergoing an appendectomy; and (2) to study the association between imaging and negative appendectomy rates (NARs) among these subgroups.

METHODS

Retrospective review of children presenting to 40 US pediatric emergency departments from 2005 to 2009 (Pediatric Health Information Systems database). Children undergoing an appendectomy were stratified by age and gender for measuring the association between ultrasound and CT use and the outcome of negative appendectomy.

RESULTS

A total of 8 959 155 visits at 40 pediatric emergency departments were investigated; 55 227 children had appendicitis. The NAR was 3.6%. NARs were highest for children younger than 5 years (boys 16.8%, girls 14.6%) and girls older than 10 years (4.8%). At the institutional level, increased rates of diagnostic imaging (ultrasound and/or CT) were associated with lower NARs for all age and gender subgroups other than children younger than 5 years, The NAR was 1.2% for boys older than 5 years without any diagnostic imaging.

CONCLUSIONS

The impact of diagnostic imaging on negative appendectomy rate varies by age and gender. Diagnostic imaging for boys older than 5 years with suspected appendicitis has no meaningful impact on NAR. Diagnostic strategies for possible appendicitis should incorporate the risk of negative appendectomy by age and gender.

Low-dose abdominal CT for evaluating suspected appendicitis

BACKGROUND

Computed tomography (CT) has become the predominant test for diagnosing acute appendicitis in adults. In children and young adults, exposure to CT radiation is of particular concern. We evaluated the rate of negative (unnecessary) appendectomy after low-dose versus standard-dose abdominal CT in young adults with suspected appendicitis.

METHODS

In this single-institution, single-blind, noninferiority trial, we randomly assigned 891 patients with suspected appendicitis to either low-dose CT (444 patients) or standard-dose CT (447 patients). The median radiation dose in terms of dose-length product was 116 mGy·cm in the low-dose group and 521 mGy·cm in the standard-dose group. The primary end point was the percentage of negative appendectomies among all nonincidental appendectomies, with a noninferiority margin of 5.5 percentage points. Secondary end points included the appendiceal perforation rate and the proportion of patients with suspected appendicitis who required additional imaging.

RESULTS

The negative appendectomy rate was 3.5% (6 of 172 patients) in the low-dose CT group and 3.2% (6 of 186 patients) in the standard-dose CT group (difference, 0.3 percentage points; 95% confidence interval, -3.8 to 4.6). The two groups did not differ significantly in terms of the appendiceal perforation rate (26.5% with low-dose CT and 23.3% with standard-dose CT, P=0.46) or the proportion of patients who needed additional imaging tests (3.2% and 1.6%, respectively; P=0.09).

CONCLUSIONS

Low-dose CT was noninferior to standard-dose CT with respect to negative appendectomy rates in young adults with suspected appendicitis. (Funded by GE Healthcare Medical Diagnostics and others; ClinicalTrials.gov number, NCT00913380.).

ACR Appropriateness Criteria® right lower quadrant pain--suspected appendicitis

The diagnostic imaging of patients presenting with right lower quadrant pain and suspected appendicitis may be organized according to age and gender and to the presence or absence of "classic" signs and symptoms of acute appendicitis. Among adult patients presenting with clinical signs of acute appendicitis, the sensitivity and specificity of CT are greater than those of ultrasound, with improved performance when CT is performed with intravenous contrast. The use of rectal contrast has been associated with decreased time in the emergency department. Computed tomography has also been shown to reduce cost and negative appendectomy rates. Both CT and ultrasound are also effective in the identification of causes of right lower quadrant pain unrelated to appendicitis. Among pediatric patients, the sensitivity and specificity of graded-compression ultrasound can approach those of CT, without the use of ionizing radiation. Performing MRI after inconclusive ultrasound in pregnant patients has been associated with sensitivity and specificity of 80% to 86% and 97% to 99%, respectively. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

The negative appendectomy rate: who benefits from preoperative CT?

OBJECTIVE

The purpose of this article is to determine the negative appendectomy rates of patients who did and did not undergo preoperative CT and to determine, more specifically, whether men benefit from preoperative CT.

MATERIALS AND METHODS

We identified 512 patients who had a nonincidental appendectomy between July 1, 2002, and June 30, 2007. Pathology records were compared with a radiology records search to determine which patients underwent preoperative CT. Proportions of patients were compared between groups using the Fisher exact test.

RESULTS

Of 512 patients who had a nonincidental appendectomy, 465 (91%) underwent preoperative CT, and 47 (9%) underwent appendectomy only on the basis of clinical findings. Overall, 22 of 465 patients (4.7%) who underwent preoperative CT had a negative appendectomy compared with six of 47 patients who did not undergo preoperative imaging (negative appendectomy rate, 12.7%; p = 0.03). Among men, six of 237 (2.5%) with preoperative CT had a negative appendectomy, versus five of 42 without imaging (negative appendectomy rate, 11.9%; p = 0.01).

CONCLUSION

The negative appendectomy rate was decreased for adult patients who underwent preoperative CT compared with patients who did not undergo preoperative imaging. Although most prior studies have suggested that CT is efficacious only in decreasing the negative appendectomy rate among women, we found that men benefit from CT as well.

Antibiotics versus appendectomy in the management of acute appendicitis: a review of the current evidence

BACKGROUND

Acute appendicitis remains the most common cause of the acute abdomen in young adults, and the mainstay of treatment in most centres is an appendectomy. However, treatment for other intra-abdominal inflammatory processes, such as diverticulitis, consists initially of conservative management with antibiotics. The aim of this study was to determine the role of antibiotics in the management of acute appendicitis and to assess if appendectomy remains the gold standard of care.

METHODS

A literature search using MEDLINE and the Cochrane Library identified studies published between 1999 and 2009, and we reviewed all relevant articles. The articles were critiqued using the Public Health Resource Unit (2006) appraisal tools.

RESULTS

Our search yielded 41 papers, and we identified a total of 13 papers within the criteria specified. All of these papers, while posing pertinent questions and demonstrating the role of antibiotics as a bridge to surgery, failed to adequately justify their findings that antibiotics could be used as a definitive treatment of acute appendicitis.

CONCLUSION

Appendectomy remains the gold standard of treatment for acute appendicitis based on the current evidence.

Pediatric negative appendectomy rate: trend, predictors, and differentials

BACKGROUND

Appendectomy is one of the most commonly performed emergency operations in children. The diagnosis of appendicitis can be quite challenging, particularly in children. We set out to determine the accuracy of diagnosis of appendicitis by analyzing the trends in the negative appendectomy rate (NAR) using a national database.

MATERIALS AND METHODS

Analysis of the Kids Inpatient Database (KID) was performed for the years 2000, 2003, and 2006 on children with appendectomy, excluding incidental appendectomies. Children (<18 y) without appendicitis but who underwent appendectomies were classified as negative appendectomies (NA), and those with appendicitis as positive appendectomies (PA). Comparisons were made between those with PA versus NA by demographic characteristics. The subset of patients with NA was then further analyzed.

RESULTS

An estimated 250,783 appendectomies met the inclusion criteria. The NAR was 6.7%. Length of stay (LOS) was longer in NA versus PA (7 versus 3 d, P < 0.05). The NAR was increased in children under 5 y (21.1% versus 5.4% for among the 5-10 y versus 5.9% among the >10 y, P < 0.0001) and in females (9.3% versus 5.1%, P < 0.001). On multivariate analysis, increasing age was associated with lower odds of NA (OR = 0.92, P < 0.001). Females, rural hospitals, and Blacks were significantly more likely to experience NA.

CONCLUSIONS

Younger age, female gender, Black ethnicity and rural hospitals are independent predictors of NA. These factors can be incorporated into diagnostic algorithms to improve the accuracy of diagnosis of appendicitis in children.

Appendicitis, Body Mass Index, and CT: Is CT More Valuable for Obese Patients than Thin Patients?

The purpose of our study is to determine whether body mass index (BMI = weight in kg/height in meters2) was related to the rate of negative appendectomy in patients who underwent preoperative CT. A surgical database search performed using the procedure code for appendectomy identified 925 patients at least 18 years of age who underwent urgent appendectomy between January 1998 and September 2007. BMI was computed for the 703 of these 925 patients for whom height and weight information was available. Patients were stratified based on body mass index (BMI 15-18.49 = underweight; 18.5-24.9 = normal weight; 25–29.9 = overweight; 30-39.9 = obese; > 40 = morbidly obese). Negative appendectomy rates were computed. Negative appendectomy rates for patients who did and did not undergo preoperative CT were 27 per cent and 50 per cent for underweight patients, 10 per cent and 15 per cent for normal weight patients, 12 per cent and 17 per cent for overweight patients, 7 per cent and 30 per cent for obese patients, and 10 per cent and 100 per cent for morbidly obese patients. The difference in negative appendectomy rates for overweight patients, obese patients, and morbidly obese patients who underwent preoperative CT as compared with patients in the same BMI category who did not undergo preoperative CT was statistically significant ( P ≤ 0.001). The negative appendectomy rates for overweight patients, obese patients, and morbidly obese patients who underwent preoperative CT were significantly lower than for patients in these same BMI categories who did not undergo preoperative CT.

Gynecologic pathologies in our appendectomy series and literature review

PURPOSE

Appendectomy applied from the diagnosis of acute appendicitis is one the most common operations in surgery. The rates of negative appendectomy are still high. The rates of negative appendectomy in males and females differ and are higher in females. In our study, these differences, particularly in females, were studied and possible solutions were discussed.

METHODS

Between October 2002 and October 2009, among women receiving urgent appendectomies, those whose primary cause was gynecological pathology were studied retrospectively. All our women subjects were examined by preoperative gynecologists. After gynecological consultation, the patients were evaluated by a general surgeon due to lack of urgent ultrasonography, computed tomography (CT) and diagnostic laparoscopy and the patient received appendectomy due to acute appendicitis.

RESULTS

In our series of 1,969 appendectomies, the rate of female/male is 811/1,158. It was determined that the primary cause in 47 (47/811; 5.8%) women with applied appendectomy was gynecological pathology. As a gynecological pathology, it was observed that the most common cause was ovarian cyst ruptures at a rate of 72.3%. The negative appendectomy rate in males was found to be 14.94% (173/1,158), and in females it was 22.56% (183/811). The difference between them is significant (P < 0.01). Of these women, 5.8% were gynecologically-induced and 16.76% were unrelated to gynecological causes.

CONCLUSION

We believe that gynecological consultation before appendectomy in women is necessary, but not sufficient. It is also important that at least one of the facilities, such as us, CT, magnetic resonance imaging, and diagnostic laparoscopy should be available in surgical use for the diagnosis of negative appendicitis.

Impact of computed tomography of the abdomen on clinical outcomes in patients with acute right lower quadrant pain: a meta-analysis

BACKGROUND

Clinical evaluation alone is still considered adequate by many clinicians who treat patients with appendicitis. The impact of computed tomography (CT) on clinical outcomes remains unclear, and there is no consensus regarding the appropriate use of CT in these patients. We sought to evaluate the impact of abdominal CT on the clinical outcomes of patients presenting with suspected appendicitis.

METHODS

We conducted a systematic review of the literature to identify studies that examined clinical outcomes related to the use of abdominal CT in the diagnosis of acute appendicitis. Inclusion criteria were studies of adult patients with suspected appendicitis that evaluated the impact of abdominal CT on negative appendectomy rates, perforation rates or time to surgery. Two independent investigators reviewed all titles and abstracts and extracted data from 28 full-text articles. Statistical analysis was conducted using Review Manager 5.0.10 software.

RESULTS

The negative appendectomy rate was 8.7% when using CT compared with 16.7% when using clinical evaluation alone (p < 0.001). There was also a significantly lower negative appendectomy rate during the CT era compared with the pre-CT era (10.0% v. 21.5%, p < 0.001). Time to surgery was evaluated in 10 of the 28 studies, 5 of which demonstrated a significant increase in the time to surgery with the use of CT. Appendiceal perforation rates were unchanged by the use of CT (23.4% in the CT group v. 16.7% in the clinical evaluation group, p = 0.15). Similarly, the perforation rate during the CT era was not significantly different than that during the pre-CT era (20.0% v. 19.6%, p = 0.74).

CONCLUSION

This meta-analysis supports the hypothesis that the use of preoperative abdominal CT is associated with lower negative appendectomy rates. The use of CT in the absence of an expedited imaging protocol may delay surgery, but this delay is not associated with increased appendiceal perforation rates. Routine CT in all patients presenting with suspected appendicitis could reduce the rate of unnecessary surgery without increasing morbidity.

Negative appendicectomy and perforation rates in patients undergoing laparoscopic surgery for suspected appendicitis

BACKGROUND

Despite widespread use of imaging technologies including ultrasonography and computed tomography, rates of negative appendicectomy and perforated appendicitis remain high. This trend analysis examined whether rates of negative appendicectomy and perforated appendicitis have decreased over time, and sought to evaluate clinical predictors associated with negative appendicectomy and perforated appendicitis.

METHODS

This analysis was based on the prospective database of the Swiss Association of Laparoscopic and Thoracoscopic Surgery (SALTS). All patients aged 12 years and over undergoing emergency laparoscopic appendicectomy between 1995 and 2006 were included. Unadjusted and risk-adjusted logistic regression analyses were performed.

RESULTS

A total of 7964 patients underwent laparoscopic appendicectomy, of whom 7452 (93.6 per cent) had acute appendicitis and 512 (6.4 per cent) had a macroscopically normal appendix. Perforation occurred in 1230 (16.5 per cent) of those with appendicitis. In multivariable analysis, younger age (12-18 years), female sex, absence of local or generalized peritonitis and an early point during the study period were significant predictors of negative appendicectomy. For perforated appendicitis, significant predictors included age over 36 years, presence of localized or generalized peritonitis, and high American Society of Anesthesiologists grade. The rate of negative appendicectomy decreased from 12.7 per cent in 1995 to 2.8 per cent in 2006, there being a significant reduction in both unadjusted and risk-adjusted analyses (P < 0.001 for trend). In adjusted analyses, the rate of perforated appendicitis did not increase significantly over time.

CONCLUSION

The rate of negative appendicectomy decreased over time, without an accompanying increase in perforated appendicitis. The risk of having a negative appendicectomy was highest in girls aged 12-18 years without local or generalized peritonitis during the early study period, whereas perforation was associated with age over 36 years, presence of localized or generalized peritonitis, and greater co-morbidity. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Routine ultrasound and limited computed tomography for the diagnosis of acute appendicitis

BACKGROUND

Acute appendicitis continues to be a challenging diagnosis. Preoperative radiological imaging using ultrasound (US) or computed tomography (CT) has gained popularity as it may offer a more accurate diagnosis than classic clinical evaluation. The optimal implementation of these diagnostic modalities has yet to be established. The aim of the present study was to investigate a diagnostic pathway that uses routine US, limited CT, and clinical re-evaluation for patients with acute appendicitis.

METHODS

A prospective analysis was performed of all patients presenting with acute abdominal pain at the emergency department from June 2005 until July 2006 using a structured diagnosis and management flowchart. Daily practice was mimicked, while ensuring a valid assessment of clinical and radiological diagnostic accuracies and the effect they had on patient management.

RESULTS

A total of 802 patients were included in this analysis. Additional radiological imaging was performed in 96.3% of patients with suspected appendicitis (n = 164). Use of CT was kept to a minimum (17.9%), with a US:CT ratio of approximately 6:1. Positive and negative predictive values for the clinical diagnosis of appendicitis were 63 and 98%, respectively; for US 94 and 97%, respectively; and for CT 100 and 100%, respectively. The negative appendicitis rate was 3.3%, the perforation rate was 23.5%, and the missed perforated appendicitis rate was 3.4%. No (diagnostic) laparoscopies were performed.

CONCLUSIONS

A diagnostic pathway using routine US, limited CT, and clinical re-evaluation for patients with acute abdominal pain can provide excellent results for the diagnosis and treatment of appendicitis.

The impact of evolving management strategies on negative appendicectomy rate

AIM

The management of appendicitis has evolved from the era of open surgery with a negative appendicectomy rate ranging from 20 to 30%. Diagnostic adjuncts such as computed tomography (CT), ultrasound (US) and diagnostic laparoscopy (DL) facilitate refinement of the clinical impression in equivocal cases. The aim of this study was to determine the impact of the increased availability and selective utilization of diagnostic adjuncts on the negative appendicectomy rate.

METHOD

This was a retrospective study of all emergency appendicectomy procedures performed over two 12- month periods encompassing 1996 and 2006. Clinical, radiological, operative and pathological data were analysed. Diagnostic adjuncts were only employed in equivocal cases. Statistical analysis was performed using the chi-squared test.

RESULTS

A total of 218 and 171 patients underwent an appendicectomy in 2006 and 1996 respectively. Therewere 103 men in 1996 and 128 in 2006. There was a significant increase in laparoscopic appendicectomy [131(60%) vs 31 (18%), P > 0.001]. In addition, there was a significant increase in the use of CT (38 vs 1, P < 0.001) and US (39 vs 4, P < 0.001).There was also a significant difference in the use of DL without appendicectomy (39 vs 8, P < 0.001). The negative appendicectomy rate was lower in 2006 (15% vs 22%, P = 0.13).The perforation rates in both study periods were similar (10% vs 8%).

CONCLUSION

A policy of selective usage of diagnostic adjuncts only in equivocal cases of appendicitis does not significantly reduce the negative appendicectomy rate.

[Impact of imaging tests on the negative appendectomy rate]

INTRODUCTION

Negative appendectomies and perforated appendectomies have traditionally been quality indicators in surgery. The aim of this study is to analyze the emergency appendectomies in our hospital regarding the use of imaging tests and a review of the literature to analyze the quality of diagnosis in acute appendicitis.

MATERIAL AND METHODS

Retrospective study including all patients operated on for suspected acute appendicitis at a single institution for one year (2007). Data gathered from histology and imaging tests reports. Analysis of the histology results, imaging test used and its diagnostic accuracy. Comparison with quality levels published in the international literature.

RESULTS

A total of 394 patients were included in the study, the overall rate of negative appendectomy was 9.6%. Abdominal ultrasound (AU) was performed on 54.6% of patients and abdominal CT-scan on 10.2% of them, and 4.2% of the patients had both tests. AU positive predictive value was 82%. CT-scan positive predictive value was 97%.

CONCLUSION

The negative appendectomy rate (9.6%) in our centre shows values lower than the published ones in historical series but superior to the one published recently in the USA. The use of imaging tests in our hospital is lower than the one published in the USA, although similar to data reported in other European countries.

Making the diagnosis of acute appendicitis: do more preoperative CT scans mean fewer negative appendectomies? A 10-year study

PURPOSE

To determine the frequency of preoperative computed tomography (CT) in the evaluation of patients suspected of having appendicitis at one institution during the past 10 years and to determine whether changes in CT utilization were associated with changes in the negative appendectomy rate.

MATERIALS AND METHODS

Institutional review board approval was obtained, and a waiver of informed consent was granted for this HIPAA-compliant study. A surgical database search yielded medical record numbers of 925 patients (526 [ 56.9%] men and 399 [43.1%] women; mean age, 38 years (range, 18-95 years]) who underwent urgent appendectomy between January 1998 and September 2007. Patients who were younger than 18 years of age at the time of surgery were excluded. CT, pathology, and surgery reports were reviewed. By using logistic regression, changes in the proportion of patients undergoing CT and in the proportion of patients undergoing each year appendectomy in which the appendix was healthy were evaluated. Subgroup analyses based on patient age (<or= 45 years or > 45 years) and sex also were performed.

RESULTS

Prior to urgent appendectomy, 18.5% of patients underwent preoperative CT in 1998 compared with 93.2% of patients in 2007. The negative appendectomy rate for women 45 years of age and younger decreased from 42.9% in 1998% to 7.1% in 2007. However, the timing of the decline in negative appendectomy rates for women 45 years and younger could not be proved to be associated with the increase in CT use. There was no significant trend toward a lower negative appendectomy rate for men regardless of age or for women older than 45 years of age with increased use of preoperative CT. The shift from single-detector CT to multidetector CT and the use of decreasing section thickness also correlated with a reduction in false-positive diagnoses.

CONCLUSION

Rising utilization of preoperative CT and advances in technology coincided with a decrease in the negative appendectomy rate for women 45 years and younger but not in men of any age or women older than 45 years.

Accuracy of computed tomography in predicting appendiceal perforation

BACKGROUND

Some surgeons use nonoperative management with or without interval appendectomy for patients who present with perforated appendicitis. These strategies depend on accurately delineating perforation by computed tomography (CT). Since 2005, our institution has used an evidence-based definition for perforation as a hole in the appendix or fecalith in the abdomen. This has been shown to clearly separate those with a high risk of abscess from those without. To quantify the ability of CT to identify which patients would meet these criteria for perforation, we tested 6 surgeons and 2 radiologists who evaluated blinded CT scans.

METHODS

A junior and senior surgical residents, 2 staff interventional radiologists, and 4 attending pediatric surgeons with 3 to 30 years of experience reviewed 200 CT scans of pediatric patients who had undergone a laparoscopic appendectomy. All CT scans were reviewed electronically, and the reviewers were blinded to the results, outcome, and intraoperative findings. None of the patients had a well-formed abscess on CT. The reviewers were asked to decide only on perforated or nonperforated appendicitis according to our intraoperative definition. Clinical admission data were reviewed and compared between groups.

RESULTS

In total, the reviewers were correct 72% of the time with an overall sensitivity of 62% and a specificity of 81%. The overall positive predictive value was 67%, and the negative predictive value was 77%.

CONCLUSIONS

This study shows that in the absence of a well-formed abscess, the triage of patient care based on a preoperative diagnosis of perforation from CT may be imprudent and subject a portion of the population to an unnecessarily prolonged course of care.

The stranded stone: relationship between acute appendicitis and appendicolith

BACKGROUND/AIM

To examine the relationship between acute appendicitis and the presence of an appendicolith in abdominal CT scans of patients attending emergency services.

MATERIALS AND METHODS

Abdominal CT scan reports were retrospectively reviewed for 267 patients through the PACS database. A 16-slices MDCT GE Light Speed scanner (Milwaukee WI) was used with a scanning protocol of 5 mm axial collimation and a pitch of 1.0, along with oral contrast material (Gastrografin 3.7% diatrizoate meglumine) and 140 mL of intravenous (IV) nonionic contrast material (Omnipaque). Particular attention was given to the study protocol, patients' age, and gender.

STATISTICAL ANALYSIS

We used MS-EXCEL and SPSS version 12.0 to perform chi-square and Fisher's exact tests. Bookends and Papers, components in Mac OS X software, were used for literature reviews and the organization of results.

RESULTS

Two hundred and sixty-seven abdominal CT scan reports were examined along side their respective images on a GE Centricity workstation. Thirty-four (12.7%) were labeled as acute appendicitis cases based on the CT findings and the rest were assigned other diagnoses. Twenty-six of the 267 CT scan reports were plain studies and 241 were contrast-enhanced scans. Less than half of the patients (123, 46.1%) were males and 144 (53.9%) were females. Thirteen males (48.1%) and 14 (51.9%) females were found to have an appendicolith. Only 3% in the <or= 11 years' age group, in contrast to 40% in the 11-20 years' age group, was diagnosed with appendicitis. The incidence in other age groups was as follows: 19% in the 21-30, 14% in the 31-40, 2.5% in the 41-50, 8% each in the 51-60 and 61-70, and none in the >or=71 years' age groups.

CONCLUSIONS

We conclude that the presence of an appendicolith i) has no particular predilection for gender or age, and ii) is not associated with a diagnosis of appendicitis.

Acute appendicitis: is removal of a normal appendix still existing and can we reduce its rate?

BACKGROUND/AIM

To determine the incidence of negative appendectomies and to identify factors that may reduce the risk of having the normal appendices removed surgically.

DESIGN

Cross-sectional study.

SETTING

College of Medicine and King Khalid University Hospital, Riyadh, Saudi Arabia.

MATERIALS AND METHODS

The surgical and histological data of 852 patients who underwent appendicectomy were reviewed. All incidental or interval appendicectomies were excluded. Only patients who were admitted and whose appendices were removed and subjected to histology were included (585 patients). The data on patients who had a normal appendix on histology further analyzed to include demographics, specific investigations, operative findings of the appendix and additional operative findings that need other surgical procedures.

RESULTS

A normal appendix was removed in 54 (9.2%) of the patients. Only 5.5% of those patients had a computed tomography (CT) scan preoperatively and 3.7% had diagnostic laparoscopy. In 21 patients, additional operative and histological findings were obtained that might have caused the right lower abdominal pain.

CONCLUSION

In spite of the advances in the diagnostic and imaging techniques, the rates of negative findings on appendicectomy have not decreased much. Clinical judgment is still the most important factor in the management of patients with suspected acute appendicitis. The routine use of CT scan or diagnostic laparoscopy for all patients who are suspected to have appendicitis is neither cost-effective nor safe.

[Appendiceal mucoceles, pseudomyxoma peritonei and appendiceal mucinous neoplasms: update on the contribution of imaging to choice of surgical approach]

INTRODUCTION

The treatment of pseudomyxoma peritonei (PMPs) and appendiceal mucocele (AM) has changed radically. To assess the contribution of preoperative imaging to the treatment strategy and choice of approach, a surgeon and a radiologist different from the initial radiologist examined the files of all patients treated for PMP or AM in four facilities in one district from January 1, 1996, through December 31, 2008.

PATIENTS AND METHODS

The study included 27 patients (20 men and seven women, mean age: 63+/-13 years). Eleven patients had an intact AM, seven synchronous PMP (malignant appendiceal lesion in two of seven), six metachronous PMP (five with peritoneal mucinous carcinomatosis and one with diffuse peritoneal adenomucinosis) and three a ruptured AM but not PMP. The incidence of mucin-secreting tumors observed (27 cases in 12 years in a region of 500 000 inhabitants) corresponds to a prevalence of approximately five cases per year per million inhabitants. Acute clinical pictures (7/27) were significantly more frequent for the malignant forms (5/7) (p<0,02).

RESULTS AND DISCUSSION

The overall sensitivity of computed tomography (CT) for all the criteria studied was 93%. The predictive value for AM rupture of visualization of thick calcifications was 100%. On the other hand, rupture never occurred when the CT showed an AM under pressure, with thin walls and septa. The predictive value for PMP of "scalloping" was 100%. The diagnostic accuracy of the initial reading was 25/27 for the imaging overall and 25/25 for the CT. Preoperative visualization of the exact size of the intact AM or of diagnostic information about ruptured AM and PMP helped to select an appropriate approach in 25 of 27 cases.

Current and emerging technologies in melanoma diagnosis: the state of the art

Relative to other specialties, dermatologists have been slow to adopt advanced technologic diagnostic aids. Most skin disease can be diagnosed by simple visual inspection, and the skin is readily accessible for a diagnostic biopsy. Diagnostic aids, such as total body photography and dermoscopy, improve the clinician's ability to diagnose melanoma beyond unaided visual inspection, however, and are now considered mainstream methods for early detection. Emerging technologies such as in vivo reflectance confocal microscopy are currently being investigated to determine their utility for noninvasive diagnosis of melanoma. This review summarizes the currently available cutaneous imaging devices and new frontiers in noninvasive diagnosis of skin disease. We anticipate that multimodal systems that combine different imaging technologies will further improve our ability to detect, at the bedside, melanoma at an earlier stage.

Optimizing the role of imaging in appendicitis

Acute appendicitis is the most common acute abdominal condition that requires surgical intervention in childhood. From the diagnostic performance perspective, computed tomography (CT) has a significantly higher sensitivity than does ultrasound (US) for diagnosing appendicitis in children; from the safety perspective, however, one should consider the radiation associated with CT, especially in children. There is strong evidence supporting improved patient outcomes in children with suspected acute appendicitis who undergo CT scanning. Nevertheless, we should keep in mind that for a single abdominal CT study in a 5-year-old child, the lifetime risk of radiation-induced cancer would be 26.1 per 100,000 in female and 20.4 per 100,000 in male patients, based on probabilistic models designed with data from atomic bomb survivors. An integrated clinical-imaging approach, applying clinical scores that are able to predict which children with acute abdominal pain do or do not have a high probability of presenting with appendicitis may improve the effectiveness of the imaging diagnosis of appendicitis at the hospital level. Such an approach could avoid exposure of children who at low risk for appendicitis to unnecessary diagnostic tests and eventually, to radiation.

The accuracy and role of cross-sectional imaging in the diagnosis of acute appendicitis

Based on current literature review, most patients with suspected or possible appendicitis should undergo cross-sectional imaging. CT scanning is preferred in most patients; US is recommended in children or pregnant women. MRI is usually indicated in women or children with nondiagnostic US. Thin young men with classic history, laboratory studies, and examination are best managed with standard appendectomy without imaging. Most other patients should undergo cross-sectional imaging (i.e., CT scan).

Negative appendectomy and imaging accuracy in the Washington State Surgical Care and Outcomes Assessment Program

OBJECTIVE

To evaluate negative appendectomy (NA) and the relationship of NA and computed tomography (CT) and/or ultrasound (US). SUMMARY BACKGROUND INFORMATION: NA may be influenced by the use and accuracy of preoperative CT/US. The Surgical Care and Outcomes Assessment Program (SCOAP) gathers chart-abstracted process of care data (such as CT/US accuracy) for general surgical procedures (including appendectomy) at most Washington State hospitals.

METHODS

We determined the prevalence of NA and CT/US concordance at the 15 SCOAP hospitals with >50 consecutive patients undergoing appendectomy (2006-2007).

RESULTS

The number of patients who underwent urgent appendectomies was 3540. The percentage of patients who had imaging (CT-91%) was 86% (women-89%, men-83%). The use of imaging ranged across hospitals from 56% to 97%. There was 91% agreement between imaging and pathology report findings (92.3%-CT and 82.4%-US). The overall rate of NA was 6% (women-8%, men-4%). The prevalence of NA was 9.8% among patients having no imaging, 8.1% among those having an US, and 4.5% in those having a CT. Among patients with NA, CT/US was obtained in 75%; correct in 10% and incorrect or ambiguous in 65%. Higher rates of NA were correlated with lower rates of CT/US concordance (r = -0.57). There was no significant difference in rates of perforation between those with (17%) and without (15%) imaging (P = 0.2). There were significant increases in the use of CT/US and decreases in NA over the time period (P < 0.01).

CONCLUSIONS

The prevalence of NA at SCOAP hospitals decreased significantly. Variation in NA between hospitals was linked closely to CT/US accuracy suggesting CT/US accuracy should be considered a measure of quality in the care of patients with presumed appendicitis.