From the Guidelines
Clinical evaluation for inguinal hernia should begin with a thorough physical examination, and when necessary, ultrasound should be used as the first-line imaging modality due to its high sensitivity and lack of radiation. This approach is supported by the fact that early detection of complications such as bowel strangulation is crucial to reduce morbidity and mortality rates [ 1 ]. The study by Birindelli et al. published in the World Journal of Emergency Surgery in 2017 emphasizes the importance of early intervention in cases of suspected intestinal strangulation, highlighting that patients should undergo emergency hernia repair immediately when intestinal strangulation is suspected [ 1 ].
When it comes to diagnostic tests, several factors can predict bowel strangulation, including systemic inflammatory response syndrome (SIRS), contrast-enhanced CT findings, lactate, serum creatinine phosphokinase (CPK), and D-dimer levels [ 1 ]. However, the most recent and highest quality study suggests that lactate level is a useful predictor of non-viable bowel strangulation, with an arterial blood lactate level of 2.0 mmol/L or greater being significantly associated with a lack of viability [ 1 ].
In terms of imaging modalities, CT scanning is generally reserved for emergency situations where complications like strangulation or bowel obstruction are suspected [ 1 ]. However, for routine evaluation of inguinal hernia, ultrasound is the preferred first-line imaging modality due to its high sensitivity, lack of radiation, and cost-effectiveness. Key points to consider in the evaluation of inguinal hernia include:
- Physical examination as the gold standard for diagnosis
- Ultrasound as the first-line imaging modality for inconclusive physical examinations
- CT scanning for emergency situations with suspected complications
- Lactate level as a predictor of non-viable bowel strangulation
- Early intervention in cases of suspected intestinal strangulation to reduce morbidity and mortality rates.
From the Research
Evaluation Modalities for Inguinal Hernia
- Physical examination is usually sufficient to make the diagnosis of inguinal hernia, as stated in 2 and 3
- Imaging modalities such as ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) can be used to evaluate inguinal hernia, especially in cases where the diagnosis is uncertain or in athletes without a palpable impulse or bulge on physical examination 2, 4, 3, 5, 6
- Ultrasonography has emerged as a convenient imaging tool for diagnosing inguinal hernia due to its portability and absence of radiation, as mentioned in 4
- CT scans can be used to detect and classify inguinal hernia, with prone-position CT being more effective than supine-position CT, as shown in 5
- MRI has higher sensitivity and specificity than ultrasonography and can be useful for diagnosing occult hernias, as stated in 3
Specific Uses of Imaging Modalities
- Ultrasonography is indicated for recurrent hernia, suspected hydrocele, or when the diagnosis is uncertain 2, 4, 3
- CT scans can be used to evaluate the anatomy of the inguinal region and detect occult hernias 5, 6
- MRI can be used to diagnose occult hernias if clinical suspicion is high despite negative ultrasound findings 3
Comparison of Imaging Modalities
- Ultrasonography is a convenient and portable imaging modality, but may not be as sensitive or specific as MRI or CT scans 4, 3
- CT scans are more effective than ultrasonography in detecting and classifying inguinal hernia, especially in prone position 5
- MRI has higher sensitivity and specificity than ultrasonography, but may not be as readily available or cost-effective 3