PMC4701369_01
A 53-year-old male who underwent orthotopic liver transplantation.. A, B. Coronal reconstructed image of portal venous phase images of a computed tomography (CT) scan obtained 6 years (A) and 2 weeks (B) before transplantation. Compared with the older image, the image obtained 2 weeks prior to surgery demonstrates the development of cavernous transformation (white arrowhead) and partial luminal narrowing of the extrahepatic portal vein (white arrows) due to a chronic flat thrombus (black arrowhead). Large splenorenal collateral vessels (black arrows) are observed in both studies. C, D. On Doppler ultrasonography (C) performed on post-transplantation day 2 a few hours after emergency portal venous thrombectomy, the flow velocity sampled at the right portal vein was 20-30 cm/sec. An unequivocal hepatopetal color signal in the portal vein branches (arrows) and the right hepatic artery (arrowhead) is seen. Subsequent SonoVue contrast-enhanced ultrasonography (D) confirms unequivocally the influx of the intravenous contrast agent in the right portal vein (arrows) and hepatic artery (arrowheads). E, F. Doppler ultrasonography delivered on post-transplantation day 3 shows a continuous flow signal in the portal vein near the hilum (E), but even there the flow velocity had fallen to approximately 10 cm/sec. At the periphery of the graft (F), the power Doppler flow signal (arrowhead) looks weak and only manages to partially propagate within the portal vein lumen (arrows). G. Coronal reconstructed image of the portal venous phase of CT shows that the portal vein (white arrow) is patent. Luminal narrowing of the recipient-side extrahepatic portal vein (white arrow) is present with a diameter of 6 mm but was not considered a complication of the anastomosis (white arrowhead) because the same narrowing was observed on preoperative CT (B). Persistent splenorenal shunts are present (black arrow). The graft liver shows multifocal wedge-shaped parenchymal regions with decreased perfusion, suggesting ischemic injuries (black arrowheads). H. Direct portography demonstrates marked portal perfusion steal into the splenorenal shunt (black arrows). The partially narrowed recipient portal vein (white arrow) and the diameter mismatch at the anastomosis site (white arrowhead) are displayed. The pressure gradient across the narrowed segment was 3 mm Hg. Vascular stent insertion and balloon angioplasty were immediately performed. I. Doppler ultrasonography after portal vein intervention reveals restoration of the portal venous color flow signals, including those located at the graft periphery. The flow velocity sampled at the right portal vein measured 20 cm/sec. J. A coronal reconstruction image from CT obtained 1 month after liver transplantation shows the stent (white arrow) remaining fully expanded and patent. Splenorenal collateral vessels persist (black arrows).
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Preoperative CT revealed partial luminal narrowing of the extrahepatic portal vein by chronic flat thrombi and the development of cavernous transformation along with large splenorenal collateral vessels (Fig. 1A, B). ALT, and bilirubin levels were 2,405 IU/L, 1,433 IU/L, and 4.3 mg/dL, respectively. An emergency operation was performed, and the portal vein thrombus was removed. A few hours later, a Doppler ultrasonography study using a GE Logiq E9 Ultrasound System (GE Healthcare, Milwaukee, WI, USA) with a 1-5-MHz convex probe demonstrated intact hepatic vascular perfusion, and the portal vein showed an intact color Doppler signal with a flow velocity of approximately 20-30 cm/sec (Fig. 1C). Contrast-enhanced ultrasonography was performed after bolus injection of 2.4 mL SonoVue (Bracco S.p.A., Milan, Italy) through a 21-gauge peripheral intravenous cannula followed by 5-mL saline flush and a robust hepatopetal influx of intravenous contrast agent, confirming the patency of both the hepatic artery and the portal vein (Fig. 1D). Medical Solutions, Erlangen, Germany) with a 2-5-MHz convex probe suggested compromised portal perfusion, as the portal venous flow velocity sampled near the liver hilum was around 10 cm/sec (Fig. 1E). Moreover, power Doppler ultrasonography identified weak intermittent portal venous flow signals at the graft periphery, which did not seem to properly propagate within the vessel lumen (Fig. 1F). Meanwhile, the hepatic arterial color Doppler signal and spectral wave pattern were normal. The scan revealed partial luminal narrowing in the pre-anastomosed recipient segment with a diameter of 0.6 cm (Fig. 1G), which was apparently irrelevant to the anastomosis complication, because such narrowing was also observed in a preoperative CT scan without remarkable interval change (Fig. 1B). Suspecting portal venous perfusion steal, the patient underwent direct portography, which confirmed massive diversion of the portal venous circulation through the splenorenal shunt (Fig. 1H). After the intervention, Doppler ultrasonography showed restoration of the portal venous flow (Fig. 1I), and the blood chemistry including the liver enzymes and bilirubin levels rapidly normalized. Although a large splenorenal shunt remained, the liver parenchyma recovered a normal appearance (Fig. 1J).