Radiographic characteristics of postinjury splenic autotransplantation: avoiding a diagnostic dilemma

Splenic autotransplantation after postinjury splenectomy has been advocated to augment the immune response to infection and prevent overwhelming postsplenectomy sepsis. Postoperative computed tomographic (CT) scans in patients undergoing splenic autotransplantation reveal multiple intra-abdominal fluid collections that may appear similar to abscesses. This presents a diagnostic dilemma. In the past, one of our patients underwent percutaneous drainage of such collections that were sterile, and one patient required operative evacuation of infected implants. The purpose of this study was to determine whether there is a characteristic radiographic appearance of splenic implants, whether this appearance changes with time, and whether implants can be differentiated from abdominal abscesses.

Patients at our Level I trauma center who underwent operative therapy for splenic injury from January 1995 to May 2002 were identified using our trauma registry. Charts were reviewed and CT scans read in a blinded fashion by a radiologist.

During the study period, 505 patients were admitted for splenic trauma. One hundred forty-five patients (29%) required operative intervention for splenic injuries. Splenorrhaphy was performed in 27 patients and splenectomy was required in 118 patients. Twenty-three patients had splenic autotransplantation into the omentum, of whom 11 underwent postoperative CT scanning for clinical suspicion of intra-abdominal abscess. On average, 2.7 scans were obtained per patient, ranging from 4 to 113 days postoperatively. Imaging revealed low-density fluid collections in the anterior abdomen in 10 of 11 patients. Time-related radiographic changes (early rim enhancement and late shrinkage) of the implants were noted, but splenic implants lacked surrounding omental fat stranding or other inflammatory changes typical of an abscess. The patient with infected splenic implants had air bubbles within the fluid collections, a characteristic finding of an abscess.

Autotransplanted splenic tissue may resemble an abscess on CT scanning, but splenic implants have distinct and time-related characteristic findings. Recognition of these unique features may allow differentiation of a splenic implant from an abscess, thus avoiding unwarranted intervention.