Point-of-care Transperineal Ultrasound to Diagnose Abscess in the Emergency Department

Diffusion-Weighted MRI in Perianal Abscess: Role and Comparison With Contrast-Enhanced MRI

BACKGROUND

Perianal abscess is a clinical infective and/or inflammatory collection in the perianal region, one entity of a large group of anal and perianal disorders. Perianal abscesses are often seen as a complication of grade 2 and grade 4 perianal fistulas from St. James's University Hospital classification. Several imaging modalities have been tried in the past for adequate assessment of perianal abscess with contrast-enhanced magnetic resonance imaging (CE-MRI) providing the most accurate results. Diffusion-weighted imaging (DWI) is an emerging sequence that can provide comparable results to CE-MRI in diagnosing and characterizing perianal abscess. The main objective of this study is to assess the role of DWI in adequate identification and assessment of perianal abscess and compare the final results with contrast-enhanced images.

METHODS

Twenty patients with complicated perianal fistula with clinically suspected perianal abscess were evaluated with DWI and CE-MRI. This study was a comparative cross-sectional study conducted in the Department of Radiodiagnosis and Imaging, All India Institute of Medical Sciences, Bhopal, India. Chi-square test was done to find the association between categorical variables. Kappa test was used to find the agreement between two different tests. Receiver operating characteristics (ROC) analysis was done to estimate the area under the curve in predicting the outcome. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were used to measure the validity of the tests.

RESULTS

DWI is a very sensitive MRI sequence and is equivalent to CE-MRI to detect the location and analyzing the loco-regional extent of abscess in complicated perianal fistula cases. DWI is also very sensitive and superior to T2 short tau inversion recovery (STIR) in differentiating perianal abscess from perianal inflammation without abscess.

CONCLUSION

DWI can be used as an alternative to post-contrast fat-suppressed MRI in precisely defining the location and extent of anal and perianal abscesses and disease activity in complicated fistula cases.

Anorectal emergencies: WSES-AAST guidelines

Anorectal emergencies comprise a wide variety of diseases that share common symptoms, i.e., anorectal pain or bleeding and might require immediate management. While most of the underlying conditions do not need inpatient management, some of them could be life-threatening and need prompt recognition and treatment. It is well known that an incorrect diagnosis is frequent for anorectal diseases and that a delayed diagnosis is related to an impaired outcome. This paper aims to improve the knowledge and the awareness on this specific topic and to provide a useful tool for every physician dealing with anorectal emergencies.The present guidelines have been developed according to the GRADE methodology. To create these guidelines, a panel of experts was designed and charged by the boards of the World Society of Emergency Surgery (WSES) and American Association for the Surgery of Trauma (AAST) to perform a systematic review of the available literature and to provide evidence-based statements with immediate practical application. All the statements were presented and discussed during the WSES-AAST-WJES Consensus Conference on Anorectal Emergencies, and for each statement, a consensus among the WSES-AAST panel of experts was reached. We structured our work into seven main topics to cover the entire management of patients with anorectal emergencies and to provide an up-to-date, easy-to-use tool that can help physicians and surgeons during the decision-making process.

Transperineal Ultrasound in the Diagnosis of Proctitis in the Emergency Department

BACKGROUND

Patients with anorectal complaints commonly present to the emergency department (ED). In patients with prior history of pelvic radiation and those with risk factors for sexually transmitted infections, proctitis is frequently on the differential diagnosis. Computed tomography (CT) scans are frequently done in patients with atypical presentations and those with broader differential diagnoses. Although in cases with suspected uncomplicated proctitis, conducting a point-of-care transperineal ultrasound (TPUS) may provide sufficient data to confirm the diagnosis and ascertain a safe plan for outpatient management, thus limiting the need for CT scan, a frequent flow-limiting step in the ED.

CASE REPORT

In this article, we present a brief case series of patients presenting to the ED with anorectal complaints in whom TPUS revealed circumferential symmetric rectal wall edema and pericolonic stranding suggestive of proctitis. History and subsequent imaging further supported these diagnoses; we also briefly detail the patients' clinical course and outcomes. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We propose the use of TPUS as the screening imaging for anorectal pathologies and those with suspected proctitis to increase its use among emergency physicians. We review the main sonographic features of proctitis alongside reports from clinical cases, as well as the potential advantages of TPUS as a first-line imaging modality as compared with CT or magnetic resonance imaging. Although the complexities of anorectal anatomy can make TPUS a more difficult ultrasound modality to master, integrating TPUS into clinical practice will prove beneficial to both physician and patient.