POSTSURGICAL INTRAHEPATIC PORTAL THROMBOEMBOLISM - A POSSIBLE CAUSE OF PERFUSION DEFECTS ON CT DURING ARTERIAL PORTOGRAPHY

Objective: Our goal was to investigate unexplained nontumorous perfusi on defects on CT arterial portography (CTAP). Materials and Methods: T he CTAP images of 35 patients who underwent partial hepatectomy or ope n biopsy were analyzed. Hepatic tumors consisted of hepatocellular car cinoma (n = 18) and colorectal carcinoma metastases (n = 17). Nontumor ous perfusion defects were categorized into those previously explained and those unexplained. We investigated unexplained ones and their rel ationship with the underlying conditions. Results: Eight unexplained n ontumorous perfusion defects were found in four patients with colorect al metastases. Statistical analysis showed that the defects occurred w ith significantly higher incidence in patients with colorectal metasta ses than in those with hepatocellular carcinoma (p = 0.046, Fisher tes t). All four patients with defects underwent CTAP within 1 month after colorectal surgery. A significant difference was seen in the distribu tion of surgery-CTAP time intervals between those patients with and th ose without defects (p < 0.05, Wilcoxon-Mann-Whitney test). Intrahepat ic portal thrombi were pathologically proven in one of the four patien ts. Conclusion: Unexplained nontumorous hepatic perfusion defects may represent postsurgical portal thromboemboli.