Teaching Case

An elderly male patient with unremarkable past medical history presented to emergency department complaining of painful left groin swelling ten days after inguinal hernioplasty performed at another institution, including use of surgical mesh. Physical examination confirmed a palpable, tender left groin swelling, with stable vital signs and normal body temperature.

After laboratory tests disclosed moderate leukocytosis and increased C-Reactive Protein (98 mg/L) levels, urgent unenhanced and contrast-enhanced abdominal and pelvic CT (Fig. 1) was requested to investigate possible underlying causes of the postoperative groin swelling.
Marked inflammatory fat stranding was noted abutting the left deep inguinal ring, associated with mildly thickened ipsilateral vas deferens. The isodense-to-muscle surgical mesh was clearly identifiable with hyperattenuating metallic clips at its fixation sites. Additionally, a large fluid-attenuation collection with strongly enhancing thickened walls, consistent with an abscess, was present along the entire left spermatic cord, causing mass effect on the penile structures, and associated with ipsilateral hydrocele and vascular engorgement at the epididymal head. Colour Doppler ultrasound (not shown) did not show evidence of testicular ischaemia and acute orchitis.
Surgical reintervention was needed to drain the abscess collection and prevent sepsis.

Groin hernia repair ranks among the commonest surgical procedures worldwide, and is increasingly performed using laparoscopy, although the classical open surgical techniques remain highly valuable. Prosthetic mesh implantation currently represents the preferred approach to limit the risk of recurrence [1-4].
Although relatively uncommon (<1% of cases) compared to the huge number of hernioplasty procedures performed every year, complications involving genital tract injury may cause non-negligible concern and occasionally medico-legal litigation. Risk factors include advanced age, diabetes, obesity, cigarette smoking, and elevated anaesthesiological risk scores. The most usual intra- and early postoperative hernioplasty-related complications include urinary retention or infection, groin and scrotal haematoma, hydrocele, bacterial epididymo-orchitis, and damage or entrapment of bowel segments or urinary bladder. Spermatic cord transection or compression injury represents the most feared occurrence since it may lead to testicular ischaemia [1, 2, 4].
Groin swelling, reported in up to 20-37% of patients following inguinal hernioplasty, represents the commonest presentation of postoperative complications. Most occurrences are caused by haematoma or seroma, which are treated conservatively and generally resolve over time. Conversely, septic mesh-related collections are uncommon (0.2-0.8% of patients), usually present with cramping pain, an irreducible groin mass, fever, and leukocytosis, and should be treated aggressively including drainage, mesh removal plus antibiotics [2, 5, 6].
Initial investigation with ultrasound may promptly diagnose serous fluid collections and variable-echogenicity haematomas, but hypoechoic tissue swelling and residual hernias are difficult to interpret. Cross-sectional imaging with CT outperforms ultrasound in mesh visualization, and provides a panoramic, comprehensive visualization of normal structures and pathologic processes involving the inguinal canal and spermatic cord [5-8].
Following inguinal hernia repair, spermatic cord thickening is a relatively common finding, and normal postoperative appearances include the presence of metallic fixation clips, and the identification of linear structures corresponding to mesh implants which appear either isodense to muscle or hyperdense depending on their composition, of expanded polytetrafluorethylene (e-PTFE) or polypropylene (PP) respectively. As this case exemplifies, CT reveals abscesses as more or less homogeneous hypoattenuating collections with peripheral enhancement, sometimes surrounded by fat inflammatory changes, which may involve the subcutaneous planes, the peri-mesh structures or the spermatic cord. CT consistently differentiates abscesses from other postoperative complications such as fluid-attenuating seroma, hyperattenuating haematomas, femoral artery pseudoaneurysms, varicocele, bladder or bowel residual herniation, thus allowing correct choice between conservative treatment, percutaneous or open surgical drainage [5-8].