Accuracy of Ultrasound as a Diagnostic Tool for the Assessment of Occult Groin Hernias

Groin hernias are a common reason to attend general surgical clinic with over 71,000 groin hernia repairs carried out in England in 2014/15. Diagnosis of groin hernias is primarily a clinical one, but a significant proportion of them are symptomatic and are not clinically palpable. There are a number of investigative options available which includes herniography, ultrasound, CT and MRI. Herniography is invasive and less sensitive to diagnose occult hernias and some radiologist would consider it, unethical & obsolete. MRI and CT scan are expensive and not always available. We evaluated the role of ultrasound in the surgical management of a cohort of patients with clinically occult groin hernia in a district general hospital. A retrospective list of patients having ultrasound examination for symptomatic groin collected from radiology department. Ultrasound which confirmed presence of hernias were identified. Ultrasound findings and clinical assessment were analyzed. In patients who underwent surgery, intra-operative findings were taken as gold standard and compared with ultrasound results. Total number of hernias included in the study was 68. Male to female distribution of patients was 3.3; 1. The mean age of participants was 42 years. In 93%, the presenting symptoms were pain, lump or combination of both. 40 patients (59%) were operated from which there was PPV of 0.90 with intraoperative findings congruent with intraoperative findings. Ultrasound is non-invasive and non-ionizing radiation imaging modality for diagnosis of impalpable groin hernias with a PPV of 90%. Morbidity associated with this modality is low. It is readily available and cheaper than MRI and CT scan with no harmful ionization radiation thereby conferring a cost benefit as well. We have shown ultrasound is a suitable tool for the initial imaging investigation of occult clinically non-palpable hernia. Our review of current literature has shown wide variance of the choice of imaging technique and the accuracy of their published report.