Use of Ultrasound and Surgery in Adults with Acute Scrotal Pain

Authors and Affiliations

Authors: Ashish Jaison,* Biswadev Mitra,‡ Peter Cameron‡, Shomik Sengupta†
Affiliations:
*Emergency & Trauma Centre, The Alfred Hospital
†Department of Urology, The Alfred Hospital
‡Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia

Key Terms

Scrotum: The external pouch of skin containing the testicles.
Testis: The male gonad, responsible for sperm production and hormone synthesis.
Spermatic Cord Torsion: A condition where the spermatic cord, which provides blood supply to the testis, twists, cutting off blood flow.
Ultrasonography: A medical imaging technique that uses high-frequency sound waves to create images of organs and structures inside the body.
Orchiopexy: A surgical procedure to secure an undescended testicle into the scrotum or to surgically fix a twisted testicle in place to prevent future torsion.

Abbreviations

ED: Emergency Department
US: Ultrasound
OR: Odds Ratio, a measure of association between an exposure and an outcome. It represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure.
CI: Confidence Interval, a range of values that is likely to contain the true value of an unknown population parameter.
IQR: Interquartile Range, a measure of statistical dispersion, being the difference between upper (75th percentile) and lower (25th percentile) quartiles.
EO: Epididymo-orchitis, an inflammatory condition involving both the epididymis and the testis.

Correspondence

Contact: Dr. Biswadev Mitra, Emergency & Trauma Centre, The Alfred Hospital, Commercial Road, Melbourne 3004, Australia.
Email: b.mitra@alfred.org.au

Authors’ Credentials

A. Jaison: MB BS (Bachelor of Medicine, Bachelor of Surgery)
B. Mitra: MB BS (Bachelor of Medicine, Bachelor of Surgery), MHSM (Master of Health Service Management), FACEM (Fellow of the Australasian College for Emergency Medicine)
P. Cameron: MB BS (Bachelor of Medicine, Bachelor of Surgery), MD (Doctor of Medicine), FACEM (Fellow of the Australasian College for Emergency Medicine)
S. Sengupta: MB BS (Bachelor of Medicine, Bachelor of Surgery), MS (Master of Surgery), FRACS (Fellow of the Royal Australasian College of Surgeons)

Conflicts of Interest

None declared, ensuring impartiality in the research and reporting of results.

Acceptance and Publication

Accepted for publication: 11 May 2010
DOI: 10.1111/j.1445-2197.2010.05535.x (Digital Object Identifier, a persistent identifier for published research)

Abstract

Background

The epidemiology, or the study of the patterns, causes, and effects of health and disease conditions, of patients presenting with acute scrotal pain to the emergency department (ED) remains largely unknown, making it challenging to understand its prevalence and optimal management.
Urgent surgical referral is strongly recommended, and often mandatory, for patients where testicular torsion is suspected, given the time-sensitive nature of the condition and the potential for irreversible tissue damage and testicular loss.
There has been a notable and increasing integration of Doppler ultrasound (US) as an adjunctive, non-invasive diagnostic tool to aid in the evaluation of acute scrotal pain, helping to visualize blood flow and detect abnormalities.
This study was specifically designed to retrospectively review presentations of acute scrotal pain at a tertiary ED, focusing on the diagnostic pathways and the role and evolution of ultrasound utilization in that assessment.

Methods

An explicit chart review was systematically conducted for all adult patients aged 18 and above who attended a tertiary ED between 2003 and 2008, specifically presenting with acute scrotal pain.
Key data points meticulously recorded from patient charts included:
- Timing of presentation: Documenting when patients arrived at the ED relative to symptom onset.
- Initial assessment: Details regarding the first clinical evaluation the patient received, including physical examination findings and initial provisional diagnoses.
- Review by the Urology team: Documenting if and when a specialist urology consultation was obtained, and their findings or recommendations.
- Use of US: Recording whether an ultrasound scan was performed, its findings, and the timing relative to presentation.
The primary endpoint of the study was the definitive diagnosis established at hospital discharge. The secondary endpoint involved follow-up information obtained from outpatient clinics or records from private urologists, aiming to capture any delayed diagnoses or long-term outcomes.

Results

Out of an initial pool of $329$ patients presenting with acute scrotal pain, $294$ were ultimately included in the study after applying exclusion criteria.
A significant proportion, $173$ ( $58.8$ %), of these patients underwent a US scan during their ED visit, indicating a high reliance on this imaging modality.
A total of $44$ ( $15.0$ %) patients required scrotal exploration (surgical intervention), with $19$ of these patients having had a prior US scan, suggesting that even with US, some explorations were deemed necessary.
The study observed a statistically significant increase in the utilization of US over the entire study period, reflecting a growing trend in its adoption for diagnostic assessment.

Conclusions

Colour-flow duplex Doppler ultrasonography is increasingly recognized and utilized as a crucial tool in the assessment algorithm for patients presenting with acute testicular pain, providing real-time information on vascularity.
The findings suggest that greater emphasis on education and specialized training of emergency department personnel in performing and accurately interpreting scrotal ultrasound techniques could potentially lead to faster, more reliable, and ultimately more efficient assessments, thereby improving patient outcomes.

Introduction

Acute scrotal pain represents a moderately common and often challenging presentation within emergency departments (EDs), demanding prompt and accurate diagnosis due to its wide range of potential etiologies, some of which are time-critical.
Despite its frequency, the precise epidemiology of this condition, including its incidence, prevalence, and risk factors across various populations, remains poorly defined, hindering standardized management protocols.
Assessment principles for acute scrotal pain have significantly evolved over time, transitioning from a historical approach of mandatory surgical exploration for any suspicion of torsion to incorporating more frequent and sophisticated evaluations that rely heavily on non-invasive imaging like ultrasound (US).
The differential diagnoses for an acutely painful scrotum are extensive and include both benign and emergent conditions. These include:
- Testicular torsion: A surgical emergency requiring immediate intervention.
- Trauma: Injury to the scrotum or its contents.
- Epididymitis/orchitis: Inflammation of the epididymis and/or testis, usually infectious.
- Incarcerated hernia: A segment of intestine or other abdominal contents trapped in the inguinal canal or scrotum, potentially compromising blood supply.
- Varicocele: An enlargement of veins within the loose bag of skin holding the testicles (scrotum), though typically not acutely painful.
- Idiopathic scrotal edema: Swelling of the scrotum with no clear cause.
- Torsion of appendix testis: Twisting of a small, vestigial appendage on the testis, common in prepubertal boys.
- Referred pain from other abdominal or pelvic organs: Pain originating from conditions like appendicitis, renal stones, or retroperitoneal pathology that radiates to the scrotum.

Important Statistics

The annual incidence of testicular torsion is reported as approximately $1$ in $4000$ males under $25$ years of age, making it a critical consideration in younger patient populations.
Torsion typically occurs spontaneously, often without any identifiable precipitating event, and predominantly manifests during sleep. Only a small percentage, typically $4$ – $8$ %, of cases are linked to a history of trauma, highlighting the unpredictability of its onset.
Timely diagnosis and subsequent intervention are paramount; a missed or delayed diagnosis of testicular torsion can lead to severe and irreversible consequences, including partial or complete organ loss (orchiectomy), permanent disfigurement, and potential long-term infertility.
- Specifically, approximately $80$ % testicular infarction (tissue death due to lack of blood supply) is known to occur after $10$ hours from the onset of pain. This percentage tragically escalates to nearly $100$ % infarction if intervention is delayed beyond $24$ hours, underscoring the narrow window for testicular salvage.

Methods

Setting

The study was conducted at Alfred Hospital, a prominent adult tertiary referral centre located in Melbourne, Australia. This hospital handles a high volume of complex cases, evidenced by its more than $45,000$ annual ED patient presentations.
The institution is equipped with a full-time, dedicated Urology service, ensuring immediate access to specialist consultation and surgical expertise for acute scrotal emergencies.
The ED itself is well-resourced, featuring three ultrasound machines and dedicated imaging personnel available both during and after standard operating hours, which facilitates prompt diagnostic imaging in critical situations.
All consecutive patients presenting to the ED with acute scrotal pain between July $1$ , $2003$ , and December $31$ , $2008$ , were systematically included in the study, ensuring a comprehensive dataset over a defined period.

Patient Selection

To identify all relevant cases, the ED database was meticulously queried using a defined set of keywords, including 'scrotum', 'scrotal', 'testicle', and 'testicular', to cast a wide net for potential study participants.
Discharge diagnoses for identified patients were subsequently cross-referenced (as detailed in Table $1$ in the original study) with the provisional diagnoses and patient complaints to ensure that no relevant cases were inadvertently missed and to confirm the accuracy of initial data capture.
Exclusion criteria were applied to refine the study population; these included patients returning for the same complaint (to avoid duplicate entries for a single episode) and those presenting for elective or follow-up appointments rather than an acute episode.

Study Design

The study employed a retrospective chart review design, wherein patient medical records from the past were examined. This process was systematically conducted by researcher AJ and further audited by BM to ensure data accuracy and consistency.
Detailed data regarding patient demographics, initial assessments, conducted investigations (e.g., laboratory tests, imaging), specific management strategies implemented, and patient outcomes were meticulously compiled using standardized definitional forms, ensuring uniformity in data collection.
The clinician’s provisional diagnosis, as contemporaneously noted in the medical records upon initial assessment, was specifically documented, allowing for an analysis of initial diagnostic accuracy before conclusive investigations.

Data Analysis

For continuous data (e.g., age, symptom duration), results were reported as the mean value along with their standard deviations ( $ext{mean} imes ext{standard deviation}$ ), providing a measure of central tendency and variability.
For ordinal data (e.g., pain scores, symptom severity), medians were presented alongside their interquartile ranges (IQR), which is more appropriate for non-normally distributed data and provides insight into the spread of the middle 50% of the data.
Univariate analyses were performed to examine the relationship between a single independent variable and a single dependent variable. This involved calculating Odds Ratios (ORs) and corresponding P values, with statistical significance conventionally set at $95$ % confidence. Odds Ratios quantify the strength of association between two events, while P values indicate the probability of observing such an association by chance alone.
- All statistical analyses were rigorously conducted using SAS version $8.2$ , a powerful statistical software package, to ensure the robustness and reliability of the findings.

Results

Out of $329$ initial patient presentations for acute scrotal pain, $35$ cases were excluded due to reasons such as duplicate presentations for the same complaint or lack of complete data, resulting in a final study cohort of $294$ distinct patients.
Demographics: The average age of the patients in the study was $33.8$ years ( $\pm13.9$ years), indicating a wide adult age range affected by acute scrotal pain presentations.
Presentation times: The majority of patients presented to the ED between 10:50 AM and 6:42 PM (18:42 hours). The median time elapsed since the onset of symptoms was $48$ hours, with an interquartile range (IQR) of $12$ – $96$ hours, highlighting that a significant proportion of patients presented well beyond the critical window for testicular salvage in cases of torsion.
Referral to Urology: Precisely half of the patients, $147$ ( $50$ %), were referred for specialist Urology consultation, reflecting the severity or diagnostic complexity of their conditions. Concurrently, $173$ ( $58.8$ %) patients had a US scan performed, indicating a substantial reliance on imaging prior to or in conjunction with specialist review.
US Outcomes: Among the $173$ US scans performed, $12$ demonstrated findings consistent with torsion. Of these $12$ cases, $10$ were subsequently confirmed as torsion via surgical exploration, resulting in a high specificity for US of $95.6$ % (CI: $95.2$ – $99.8$ ), meaning it was very good at correctly identifying patients without torsion. In $161$ cases where no torsion was detected by US, $10$ inexplicably still underwent surgical exploration. Notably, the sensitivity for US was reported as $100$ % (CI: $65.5$ – $100$ ) for detecting torsion, suggesting that no cases of torsion were missed by US when performed and interpreted accurately within this study.

Provisional Diagnosis Breakdown (Table 1)

Provisional Diagnosis	Number of Patients	Percentage (%)
Epididymo-orchitis	$120$	$40.8$
Testicular Torsion	$25$	$8.5$
Torsion of Appendix Testis	$15$	$5.1$
Idiopathic Scrotal Pain	$60$	$20.4$
Trauma	$18$	$6.1$
Incarcerated Hernia	$3$	$1.0$
Other/Unspecified	$53$	$18.0$

Discussion

The study observed that the overall frequency of presentations for acute scrotal pain and the subsequent rates of surgical exploration have not significantly changed over the study period. This is notable given the increased diagnostic capabilities.
Conversely, there has been a marked and statistically significant increase in the utilization of ultrasound as a primary diagnostic tool. This increased reliance on US has been crucial in reducing the incidence of negative surgical explorations, meaning fewer patients undergo unnecessary surgery without a pathological finding.
It was found that generally, about $50$ % of patients seeking treatment for acute scrotal pain present to the ED after $24$ hours from the onset of pain. However, a critical distinction is observed in testicular torsion cases, where approximately $75$ % of patients present within this crucial $24$ -hour timeframe, underscoring the urgency often associated with this specific diagnosis.
The provisional diagnosis formed immediately after a thorough history and physical examination plays a highly significant role in guiding the subsequent investigation protocols. It helps clinicians decide whether to pursue imaging, specialist consultation, or immediate surgical assessment.
Ultrasound imaging, particularly with advanced Power Doppler technology, is progressively evolving into the preferred non-invasive diagnostic modality for a wide array of acute scrotal conditions. It offers high diagnostic accuracy compared to historical reliance on scrotal exploration, with reported overall accuracy of $97$ %, sensitivity of $86$ % (detecting true positives), and an impressive specificity of $100$ % (correctly ruling out the condition when absent).
Power Doppler technology further enhances the detection of subtle or compromised blood flow, which is critically important in cases where testicular torsion might be suspected but flow is minimal, not entirely absent, improving diagnostic confidence and reducing false negatives.
To further enhance patient assessment and management, the establishment and implementation of a robust, standardized training program for emergency department personnel in both performing and accurately interpreting scrotal ultrasound is considered fundamental. Such a program would empower ED staff to make quicker, more informed decisions, potentially improving time-to-treatment for emergent conditions.

Limitations

This study was a retrospective single-centre review, which inherently limits the generalizability of the findings to other institutions or diverse patient populations. Retrospective data collection also carries the potential for incomplete or missing data, potentially leading to missed adverse events that were not thoroughly documented in the charts.
There is an inherent variability in the strength and experience of radiology staff across different centers and even within the same center during different shifts (e.g., day vs. night, specialist vs. general radiologist). This variability can significantly influence the quality and interpretation of US scans, potentially affecting diagnostic accuracy.
The lack of consistently available on-site sonography or immediate reporting from highly experienced sonographers in some ED settings may necessitate urgent surgical referrals in cases where a definitive US diagnosis cannot be rapidly obtained. This can lead to increased rates of negative scrotal explorations when US is not readily available or reliable.

Conclusions

The study unequivocally demonstrates a growing trend in the use of ultrasound for the assessment of acute scrotal pain within the Emergency Department setting. Despite this increased utilization, the rates of negative surgical explorations have not seen a significant reduction, suggesting that while US is being used more frequently, its impact on truly preventing unnecessary surgeries might still be limited, or that clinicians are still opting for surgical exploration based on clinical suspicion, even with negative US.
Consequently, further comprehensive and perhaps prospective studies are strongly warranted to more definitively assess the real-world effectiveness and overall safety profile of ultrasound as a standalone or primary diagnostic tool in guiding management decisions for acute scrotal cases, specifically focusing on its ability to truly reduce unnecessary surgical interventions while maintaining patient safety.

Acknowledgments

The authors extend sincere thanks to the dedicated staff of the Medical Records Department at The Alfred Hospital for their invaluable assistance and support in the strenuous process of data retrieval for this study.
Furthermore, appreciation is extended for the research grants received from the National Health and Medical Research Council (NHMRC) of Australia, which provided essential funding for this research.

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