Multidetector computed tomography angiography in detection of active bleeding in renal and liver transplant recipients.

OBJECTIVES: The aim of this study was to evaluate the effectivity of multidetector computed tomography angiography (MDCT-A) to detect active bleeding in transplant patients. MATERIALS AND METHODS: Between 1999 and 2006, 532 patients underwent renal or liver transplantation. MDCT-A was performed on recipients who displayed decreased hemoglobin levels or who had a hematoma during abdominal ultrasound imaging. The MDCT-A used a 16-detector CT device (Siemens, Sensation) with slices 0.75 mm thick after injection of nonionic contrast media (4 mL per second). A multiple intensity projection (MIP) technique was used to maintain angiographic images in the axial and coronal planes. RESULTS: MDCT-A detected active bleeding among 23 posttransplant patients: 10 of arterial origin and 13 venous, as proven either by angiography or during operation. Among 8 of the 11 patients who underwent angiographic imaging the arterial origin was embolized. For three patients the angiographic evaluation was not helpful to find the bleeding point. A cohort of 5 of 12 patients did not undergo angiographic evaluation and were followed by clinical and ultrasonographic findings. Seven patients underwent re-operating. DISCUSSION: Management of the patients who were suspected to have active bleeding after renal or liver transplantation was benefitted by MDCT-A as an accurate and feasible screening modality.

Computed tomography volumetric follow-up of graft volume in living related liver recipients.

AIM: Liver regeneration is a fascinating process that makes living related donor transplantation feasible for patients. In this study we evaluated the changes in graft volumes among living related liver transplantation (LRLT) patients using computerized tomography (CT)-assisted volumetry technique. MATERIALS AND METHODS: Thirty three patients (17 adults, 16 children) who underwent liver transplantation were included in this study. Pediatric patients were referred to as group A, and adult patients were referred to as group B. The initial graft weight measured during operation was used as the initial graft volume. All patients' graft volumes were retrospectively calculated by CT volumetry technique. The data was compared with the initial graft volume in each patient. Paired samples Student t test was used for statistical analyses. RESULTS: The graft volume increased from 2.7% to 285.6% with the mean increase 78% in group A, and 10.5% to 150.8% with a mean increase of 89% in group B. These changes were significant (P<.0001) in both groups. DISCUSSION: The liver regeneration of recipient grafts is more complicated than that of the donors. There are a limited number of reports of complete volume recovery. We observed significant volume regeneration in liver grafts after transplantation, which was easily followed by CT-assisted volumetry.

Multidetector computed tomographic angiography findings of splenic artery steal syndrome in liver transplantation.

AIMS: Splenic artery steal syndrome, a common complication in liver transplantation, is diagnosed by conventional angiography showing an enlarged splenic artery and by dynamic findings. The aim of this study was to determine multidetector computed tomographic angiography (MDCTA) findings of splenic artery steal syndrome to develop diagnostic criteria. MATERIALS AND METHODS: Ten patients were diagnosed as displaying splenic artery steal syndrome among 198 liver transplant patients. The diagnosis was confirmed by celiac angiography. In eight of them, MDCTA was performed. Axial and coronal maximum-intensity projection images were obtained in arterial and portal phases. We measured the diameter of the celiac trunk and of the splenic, left gastric, common hepatic, superior mesenteric artery, and transplant hepatic arteries. We also measured the diameter of the proximal and the distal segments of the abdominal aorta, along with the size of the spleen, the ratio of the splenic artery to the common hepatic artery, the ratio of splenic artery to transplant hepatic artery, the diameter of portal vein and superior mesenteric vein. The control group consisted of liver transplant patients with normal liver enzyme levels. We performed Student t test for statistical examination. RESULTS: The diameter of the splenic artery (P<.05), the size of the spleen (P<.01), and the ratio of the splenic to the transplant hepatic arteries (P<.05) was significant between the two groups. The diameter of the splenic artery was larger than 4 mm in all patients in the study group. CONCLUSIONS: Conventional angiography was mandatory for the diagnosis of splenic artery steal syndrome. MDCTA is a noninvasive method. Some computed tomography criteria are important for early diagnosis and treatment.