Abbreviated MRI in patients with suspected acute appendicitis in emergency: a prospective study

Diagnosis and treatment of appendicitis: systematic review and meta-analysis

BACKGROUND

The optimal diagnosis and treatment of appendicitis remains controversial. This systematic review details the evidence and current best practices for the evaluation and management of uncomplicated and complicated appendicitis in adults and children.

METHODS

Eight questions regarding the diagnosis and management of appendicitis were formulated. PubMed, Embase, CINAHL, Cochrane and clinicaltrials.gov/NLM were queried for articles published from 2010 to 2022 with key words related to at least one question. Randomized and non-randomized studies were included. Two reviewers screened each publication for eligibility and then extracted data from eligible studies. Random effects meta-analyses were performed on all quantitative data. The quality of randomized and non-randomized studies was assessed using the Cochrane Risk of Bias 2.0 or Newcastle Ottawa Scale, respectively.

RESULTS

2792 studies were screened and 261 were included. Most had a high risk of bias. Computerized tomography scan yielded the highest sensitivity (> 80%) and specificity (> 93%) in the adult population, although high variability existed. In adults with uncomplicated appendicitis, non-operative management resulted in higher odds of readmission (OR 6.10) and need for operation (OR 20.09), but less time to return to work/school (SMD - 1.78). In pediatric patients with uncomplicated appendicitis, non-operative management also resulted in higher odds of need for operation (OR 38.31). In adult patients with complicated appendicitis, there were higher odds of need for operation following antibiotic treatment only (OR 29.00), while pediatric patients had higher odds of abscess formation (OR 2.23). In pediatric patients undergoing appendectomy for complicated appendicitis, higher risk of reoperation at any time point was observed in patients who had drains placed at the time of operation (RR 2.04).

CONCLUSIONS

This review demonstrates the diagnosis and treatment of appendicitis remains nuanced. A personalized approach and appropriate patient selection remain key to treatment success. Further research on controversies in treatment would be useful for optimal management.

Quality Improvement Campaign Improved Utilization of Rapid Sequence MRI for Diagnosis of Pediatric Appendicitis

INTRODUCTION

Appendicitis is the most common indication for emergency general surgery in the pediatric population. Computed tomography (CT) or magnetic resonance imaging (MRI) may be used for diagnosis when ultrasound findings are equivocal. However, CT involves unnecessary radiation exposure if MRI is available. After introducing a rapid sequence MRI (rsMRI) appendicitis protocol at our institution, CT was still preferentially used. We therefore implemented a quality improvement (QI) campaign to reduce the rate of CTs and increase the rate of rsMRI. Here, we assess the effectiveness of the QI campaign while evaluating potential barriers to using rsMRI.

METHODS

We conducted a mixed methods study, first performing stakeholder interviews which informed the design of a QI campaign initiated in May 2021 and a midway feedback survey in December 2021. A retrospective cohort study was then performed of children evaluated for appendicitis at our institution between January 1, 2016, and April 30, 2022. CT and rsMRI rates were compared before and after QI campaign implementation.

RESULTS

There was a significant decrease in rate of CTs and increase in rate of rsMRIs performed following the initiation of the QI campaign (p < 0.0001). The rate of CT scans decreased by a factor of 0.4 while the rate of rsMRI increased by a factor of 9.5.

CONCLUSION

A successful QI campaign was initiated at our institution, resulting in decreased utilization of CT and increased use of rsMRI for the evaluation of suspected appendicitis. These results highlight the potential impact of QI projects.

LEVEL OF EVIDENCE

III.

Rapid MRI Abdomen for Assessment of Clinically Suspected Acute Appendicitis in the General Adult Population: a Systematic Review

OBJECTIVES

To perform a systematic review on the use of magnetic resonance imaging (MRI) of the abdomen to evaluate clinically suspected appendicitis in the general adult population. We examined the diagnostic accuracy, the reported trends of MRI use, and the factors that affect the utility of MRI abdomen, including study duration and cost-benefits.

METHODS

We conducted a systematic literature search on PubMed, MEDLINE, Embase, Web of Science, and Cochrane Library databases. We enrolled primary studies investigating the use of MRI in diagnosing appendicitis in the general adult population, excluding studies that predominantly reported on populations not representative of typical adult appendicitis presentations, such as those focusing on paediatric or pregnant populations.

RESULTS

Twenty-seven eligible primary studies and 6 secondary studies were included, totaling 2,044 patients from eight countries. The sensitivity and specificity of MRI for diagnosing appendicitis were 96% (95% CI: 93-97%) and 93% (95% CI: 80-98%), respectively. MRI can identify complicated appendicitis and accurately propose alternative diagnoses. The duration of MRI protocols in each primary study ranged between 2.26 and 30 minutes, and only one study used intravenous contrast agents in addition to the non-contrast sequences. Decision analysis suggests significant benefits for replacing computed tomography (CT) with MRI and a potential for cost reduction. Reported trends in MRI usage showed minimal utilisation in diagnostic settings even when MRI was available.

CONCLUSIONS

MRI accurately diagnoses appendicitis in the general adult population and improves the identification of complicated appendicitis or alternative diagnoses compared to other modalities using a single, rapid investigation.

Is it possible to predict the severity of acute appendicitis? Reliability of predictive models based on easily available blood variables

INTRODUCTION

Recent evidence confirms that the treatment of acute appendicitis is not necessarily surgical, and selected patients with uncomplicated appendicitis can benefit from a non-operative management. Unfortunately, no cost-effective test has been proven to be able to effectively predict the degree of appendicular inflammation as yet, therefore, patient selection is too often left to the personal choice of the emergency surgeon. Our paper aims to clarify if basic and readily available blood tests can give reliable prognostic information to build up predictive models to help the decision-making process.

METHODS

Clinical notes of 2275 patients who underwent an appendicectomy with a presumptive diagnosis of acute appendicitis were reviewed, taking into consideration basic preoperative blood tests and histology reports on the surgical specimens. Variables were compared with univariate and multivariate analysis, and predictive models were created.

RESULTS

18.2% of patients had a negative appendicectomy, 9.6% had mucosal only inflammation, 53% had transmural inflammation and 19.2% had gangrenous appendicitis. A strong correlation was found between degree of inflammation and lymphocytes count and CRP/Albumin ratio, both at univariate and multivariate analysis. A predictive model to identify cases of gangrenous appendicitis was developed.

CONCLUSION

Low lymphocyte count and high CRP/Albumin ratio combined into a predictive model may have a role in the selection of patients who deserve appendicectomy instead of non-operative management of acute appendicitis.

Financial and medicolegal implications of focused/fast abdominopelvic MRI exams

PURPOSE

Abbreviated MRI offers significant advantages in terms of MRI throughput, patient tolerance and expediency, and is being utilized for a variety of abdominopelvic imaging applications. However questions abound with respect to financial and medicolegal treatment of these relatively new protocols.

METHODS

A review of the relevant literature was performed.

RESULTS

There is no Current Procedural Terminology code for a "limited" MRI study, but it may not be appropriate to bill an abbreviated study the same as a more comprehensive study. With respect to medicolegal concerns, the risk of liability when missing or misinterpreting medically significant findings due to use of an abbreviated scan will turn on whether abbreviated MRI has become the standard of care.

CONCLUSION

In light of these ambiguities, it would behoove abdominopelvic imagers to advocate for their professional and subspecialty organizations to issue practice parameters/guidelines with respect to the utilization of abbreviated MRI protocols, and for the subspecialty to bill these abbreviated scans at objectively reasonable rates.