[The role of computed tomography in assessing subphrenic abscesses after posttraumatic splenectomy]

We studied subphrenic inflammatory abscesses and splenic fluid collections after splenectomy for trauma. These complications may appear early or late postoperatively; they are easily demonstrated with CT, which permits accurate spatial assessment of the lesions and appropriate treatment with percutaneous drainage. We investigated the diagnostic accuracy of CT in subphrenic inflammatory conditions after emergency splenectomy for traumatic spleen rupture and found that CT is a precious tool for rapid and easy diagnosis and follow-up of subphrenic abscesses treated with percutaneous drainage.

Thirteen patients with left subphrenic inflammatory abscesses after splenectomy for trauma were examined from 1994 to 1998. They were 9 men and 4 women ranging in age 16-67 years (mean: 32). CT demonstrated abscesses early postoperatively in 9 patients and late postoperatively (mean: 3 months) in 4 patients. Abscesses were diagnosed with CT on admission for an abdominal emergency in 3 cases; one abscess was found at outpatient US performed for persisting left abdominal pain. CT-guided percutaneous drainage was performed in all patients with the Trocar technique.

A large inflammatory liquid collection with the typical "liquid pseudospleen" appearance and characterized by tomodensitometric coefficients of corpusculated fluid was seen in 3 cases. Multiple confluent lesions with septa were found in 3 cases. Contrastography of the abscess cavity with the injection of a water-soluble iodinated contrast agent was performed in 2 cases to detect fistulas connecting to the intestinal loops. Subphrenic abscesses had the same CT patterns both early and late postoperatively, with the collection organizing into thick and corpusculated phlogistic material and exhibiting enhanced capsulofibrous differentiation. Air bubbles and water-air levels within the collection were found in 7 cases and considered a pathognomonic sign of inflammatory abscesses. A periabscessual reaction involving intestinal loops and adjacent organs was seen in 4 cases.

Splenectomy causes depressed phagocytosis and decreases serum levels of IgM and antigen response. This calls for careful selection of the patients absolutely requiring splenectomy, such as those with decompensated circulation and multiple parenchymal ruptures or spleen detachment from its stalk. Subphrenic abscesses after splenectomy account for 2.5% of postoperative complications and those after splenectomy for trauma are rarer still, with 1.3%. CT is the imaging method of choice in detecting inflammatory abscesses in the residual splenic cavity and assessing their extent. CT-guided drainage is the first-line treatment, while surgery is reserved to later stages, when drainage fails or other complications occur. Finally, CT permits accurate positioning of the catheter inserted with the Trocar technique and its immediate monitoring, which permits to assess treatment efficacy.