Teaching Case

A 74-year-old man presented to the emergency room with a painful mass within the abdominal wall of the right iliac fossa with flushed skin. Some months before he had suffered a similar clinical manifestation, which ended with a spontaneous skin fistulization. More than one year before he had undergone laparoscopic cholecystectomy.

During the first clinical manifestation a non-enhanced CT showed a hypodense collection with a small hyperdense image within (Fig. 1).
For the present maninfestation a new non-enhanced CT was performed to evaluate the position of the mass and its relations with the adjacent structures. It showed the presence of a collection within the subcutaneous fat tissue of the right iliac fossa. Within the collection a millimetric hyperdense image was recognizable (Fig. 2).
A surgical incision of the skin was executed. Histological examination proved a foreign body granuloma with traces of biliary pigment.

One year before the patient underwent laparoscopic cholecystectomy and the intervention was complicated by gallbladder rupture.
A retrospective analysis of the first CT showed that a small hyperdense image in the abdominal wall, where an abscess appeared some months later, was already recognizable (Fig. 3).
Compared with open surgery, laparoscopic cholecystectomy is associated with a lower mortality and morbidity rate, although there are two complications that had increased: bile duct injury and gallbladder rupture with bile and gallstone spillage into the abdomen [1, 2].
The incidence of gallbladder perforation during laparoscopic cholecystectomy is assessed from 6% to 40% [2].
Acute cholecystitis and adhesion, obesity, older age, male gender, and surgeon's experience are considered risk factors [2, 3].
Whether this complication occurs, dropped gallstones should be removed, although it is not always possible with laparoscopy: in 33% of cases stones are not completely removed [1].
However, in case of spillage, the conversion of laparoscopic to open cholecystectomy is not recommended; this option should be considered only if bile is infected and if there is a large number of stones that cannot be retrieved [2, 4].
In most cases the presence of unretrieved gallstones in the abdomen remains asymptomatic, also for a long time; but as foreign bodies, they can cause inflammation. Described complications include fibrosis, adhesions, fistulization with skin or with adjacent anatomical structures, abscesses formation and also sepsis. [2, 3].
The complication rate due to dropped stones is estimated as 1.7 cases per 1000 laparoscopic cholecystectomies [1].
Complications are unusual and may occur even a long time after surgery causing a diagnostic delay. Radiological investigations include mainly ultrasound and CT. In this case the awareness of the occurred operative complication helped to reach the diagnosis. In case of abdominal abscess in patients who underwent laparoscopic cholecystectomy complicated by gallbladder rupture, regardless of the time of intervention, the hypothesis of spilled stones should be considered.