The postpartum gossypiboma presenting as ureteric injury. Imaging challenges in the diagnosis of a “surgical never event”

Clinical History

A 27-year-old woman was referred for imaging studies 24 hours after a complicated emergency caesarean section. Her clinical situation was worsening with flank pain and deteriorating renal function. There was clinical suspicion of ureteric injury.

Imaging Findings

Excretory phase computed tomography (CT) imaging of the abdomen showed an enlarged right kidney without opacification of the collecting system and ureter (figure 1). This was considered as an acute, obstructive uropathy. A retrograde double JJ ureteric stent was inserted. The renal function improved, yet the pain and tenderness were stable. A follow-up abdominal film confirmed the correct position of the stent, and also showed an unexpected curvilinear metallic object in the left flank (figure 2). Retrospective analysis of the CT urogram indeed revealed high-density metallic serpenginous material surrounded by soft tissue containing areas of gas, and with “wall enhancement” (figures 3 and 4). This was initially erroneously interpreted as a bowel structure, with an anastomotic metallic suture line, but now diagnosed as a retained swab (gossypiboma). This was confirmed on subsequent surgical re-exploration.

Discussion

Gossypiboma is a descriptive term applied for post procedural retention of surgical swab or sponge. With recent developments in intraoperative governance and safety procedures, it should be considered as a “never event”. Nevertheless, it is a well-documented complication, with retained swabs accounting for the majority of foreign bodies found on post procedural imaging, especially after abdominal surgery. [1]
The clinical presentation of swab retention can be acute or delayed, with a variable and complex clinical picture, producing significant morbidity and mortality. [2] An inflammatory and fibrotic process can be triggered with surprisingly little degradation of the swab material. This is illustrated in another case where a retained thoracic swab presenting as a palpable mass was retrieved at a port-a-catheter site placed six months earlier. Gossypibomas have variable imaging characteristics, largely depending on the time of presentation. In the acute setting the spongiform material contains air bubbles and wall enhancement, thus mimicking bowel. At more delayed presentations inflammatory encapsulation, collections, granulomas and calcification gossypiboma mimic abscesses or even malignancy [1]. Figure 6 illustrates a patient presenting with right upper quadrant pain and sepsis, in whom an ill-defined rounded air filled collection was observed on an abdominal plain film. This was clinically considered to be due to emphysematous cholecystitis. CT imaging however confirmed the presence of air containing material suspicious of foreign body (figure 7). Detailed clinical history indeed established previous surgical intervention.
The diagnosis of gossypiboma can be challenging even with current imaging modalities, and when masked with an unsuspected clinical presentation. Awareness of this rare entity is extremely helpful to avoid delayed diagnosis.

Differential Diagnosis List

Final Diagnosis

Gossypiboma

URL:	https://www.eurorad.org/case/11339
DOI:	10.1594/EURORAD/CASE.11339
ISSN:	1563-4086