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

Objective: Our goal was to investigate unexplained nontumorous perfusion defects on CT arterial portography (CTAP). Materials and Methods: The CTAP images of 35 patients who underwent partial hepatectomy or open biopsy were analyzed. Hepatic tumors consisted of hepatocellular carcinoma (n = 18) and colorectal carcinoma metastases (n = 17). Nontumorous perfusion defects were categorized into those previously explained and those unexplained. We investigated unexplained ones and their relationship with the underlying conditions. Results: Eight unexplained nontumorous perfusion defects were found in four patients with colorectal metastases. Statistical analysis showed that the defects occurred with significantly higher incidence in patients with colorectal metastases than in those with hepatocellular carcinoma (p = 0.046, Fisher test). All four patients with defects underwent CTAP within 1 month after colorectal surgery. A significant difference was seen in the distribution of surgery-CTAP time intervals between those patients with and those without defects (p < 0.05, Wilcoxon-Mann-Whitney test). Intrahepatic portal thrombi were pathologically proven in one of the four patients. Conclusion: Unexplained nontumorous hepatic perfusion defects may represent postsurgical portal thromboemboli.