Tissue reactions of abdominal integuments to surgical sutures in sonography

Classical abdominal surgeries usually require long incisions of the abdominal integuments followed by tight closure with adequate suturing material. Nonabsorbable sutures may cause various reactions, including granuloma reactions, both sterile and inflammatory.

The aim of the study was to analyze prospective ultrasound examinations of the abdominal integuments in order to detect tissue reactions to surgical sutures.

For 10 years, ultrasound examinations of the abdominal integuments involved the assessment of surgical scars in all patients who underwent open or closed surgeries for various reasons (in total 2254 patients). Ultrasound examinations were performed only with the use of linear probes with the frequency ranging from 7 to 12 MHz. Each scar in the abdominal integuments was scanned in at least two planes. When a lesion was detected, the image was enlarged and the transducer was rotated by approximately 180° in order to capture the dimensions of the granuloma and the most characteristic image of the suture. Moreover, vascularization of the lesion was also assessed with the use of color Doppler mode set to detect the lowest flows.

All granulomas (19 lesions, two in one patient) created hypoechoic oval or round nodules, were relatively well-circumscribed and their size ranged from 8 × 4 mm to 40 × 14 mm. In the center of the lesion, it was possible to notice a thread that was coiled to various degrees and presented itself as a double, curved hyperechoic line. In 9 out of 19 granulomas, slight peripheral vascularization was observed. The substantial majority of the lesions (n = 15) were in contact with the fascia. In seven patients, compression with the transducer induced known local pain (n = 4) or intensified pain that had already been present (n = 3); all of these granulomas infiltrated the fascia and showed slight peripheral vascularization. Cutaneous fistulae developed in two patients with purulent reactions to the running stitch (in one patient - two fistulae).

Suture granulomas in the abdominal integuments manifest themselves as nodular hypoechoic lesions, usually localized at the edge of the fascia - subcutaneous fat. A pathognomonic sign of this type of granulomas is the presence of a thread in their center that usually manifests itself as a chaotically shaped, double hyperechoic line. In some granulomas, particularly those with clinical presentation, slight peripheral vascularization is observed.