Changes in contrast enhancement of hepatocellular carcinoma and liver: effect of temporary occlusion of a hepatic vein evaluated with spiral CT

Retrograde-outflow percutaneous isolated hepatic perfusion using cisplatin: A pilot study on pharmacokinetics and feasibility

OBJECTIVES

This study aimed to evaluate the feasibility and underlying pharmacokinetics of the retrograde-outflow technique for percutaneous isolated hepatic perfusion (PIHP).

METHODS

Retrograde-outflow PIHP was performed in 12 male pigs (weight, 37-44 kg) by redirecting hepatic outflow through the portal vein. Blood with cisplatin (2.5 mg/kg) in an extracorporeal circuit was circulated through the liver under isolation using rotary pumps with balloon catheters. Hepatic angiographic examinations were conducted during perfusion, and histopathological examinations of the organs were conducted after perfusion. The maximum platinum concentration (C max), area under the concentration-time curve (AUC), and chronologic laboratory data were measured.

RESULTS

Retrograde-outflow isolated hepatic angiography confirmed that contrast media flowed into the portal veins in all 12 pigs. The hepatic veins and inferior vena cava were not opacified. Hepatic C max (86.3 mg/l) was 39-fold greater than systemic C max (2.2 mg/l), and hepatic AUC (1330.8 min · mg/l) was 30-fold greater than systemic AUC (44.6 min · mg/l). Histopathological examinations revealed no ischaemic changes or other abnormalities in the liver, duodenum, small intestine, or colon. Within 1 week of the procedure, chronologic laboratory data (n = 3) normalized or returned to pre-therapy levels.

CONCLUSIONS

The retrograde-outflow technique appears to enable safe and feasible PIHP therapy.

KEY POINTS

• The portal vein acted as an outflow tract under retrograde-outflow PIHP. • Plasma hepatic-to-systemic exposure ratio was 39.2 for the maximum platinum concentration. • Plasma hepatic-to-systemic exposure ratio was 29.8 for the AUC. • The retrograde-outflow technique appears to enable safe and feasible PIHP.

Interventional treatment for unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer and third leading cause of cancer-related death in the world. The Barcelona clinic liver cancer classification is the current standard classification system for the clinical management of patients with HCC and suggests that patients with intermediate-stage HCC benefit from transcatheter arterial chemoembolization (TACE). Interventional treatments such as TACE, balloon-occluded TACE, drug-eluting bead embolization, radioembolization, and combined therapies including TACE and radiofrequency ablation, continue to evolve, resulting in improved patient prognosis. However, patients with advanced-stage HCC typically receive only chemotherapy with sorafenib, a multi-kinase inhibitor, or palliative and conservative therapy. Most patients receive palliative or conservative therapy only, and approximately 50% of patients with HCC are candidates for systemic therapy. However, these patients require therapy that is more effective than sorafenib or conservative treatment. Several researchers try to perform more effective therapies, such as combined therapies (TACE with radiotherapy and sorafenib with TACE), modified TACE for HCC with arterioportal or arteriohepatic vein shunts, TACE based on hepatic hemodynamics, and isolated hepatic perfusion. This review summarizes the published data and data on important ongoing studies concerning interventional treatments for unresectable HCC and discusses the technical improvements in these interventions, particularly for advanced-stage HCC.

Hemodynamics in rat liver tumor model during retrograde-outflow isolated hepatic perfusion with aspiration from the portal vein: angiography and in vivo microscopy

BACKGROUND

Orthograde percutaneous isolated hepatic perfusion (IHP) techniques using balloon occlusion catheters are relatively simple and facilitate repeated therapy, but they result in higher rates of leakage from the perfusion circuit into the systemic circulation. Therefore, a feasible protocol for percutaneous IHP with less leakage is required.

PURPOSE

To investigate hemodynamic changes in rat liver and tumor during retrograde-outflow isolated hepatic perfusion (R-IHP) with aspiration from the portal vein (PV).

MATERIAL AND METHODS

Animal experiments were approved by the Animal Experiment Ethics Committee of Lund University. Eighteen rats underwent R-IHP after laparotomy and catheterization of the PV and hepatic artery (HA). The HA, inferior vena cava (IVC), and PV were ligated, and flow through the suprahepatic IVC was controlled with a suture loop. The rats were divided into two groups to examine blood flow during R-IHP. Four rats (group 1) underwent arteriography via the HA with and without R-IHP, and 14 rats (group 2) were inoculated with tumor and examined by in vivo fluorescence microscopy of liver and tumor during R-IHP.

RESULTS

In group 1, hepatic arteriography during R-IHP confirmed arterioportal communication in all four rats, with the PV acting as an outflow tract. In vivo fluorescence microscopy in group 2 showed strong enhancement of tumors, and no blood supply from the portal venules to the tumors was seen in any of the 14 rats. Blood flow in the major portion of the hepatic lobules was stopped and the percentage of enhanced area was significantly lower in the normal hepatic lobules than in the tumors (P < 0.0001).

CONCLUSION

We confirmed reversal of blood flow concomitant with good perfusion of the liver tumor and with reduced perfusion of normal liver parenchyma during R-IHP.

Added value of diffusion-weighted MRI for evaluating viable tumor of hepatocellular carcinomas treated with radiotherapy in patients with chronic liver disease

OBJECTIVE

The purpose of this article is to evaluate the added value of diffusion-weighted imaging (DWI) to the diagnostic performance of conventional MRI in diagnosing viable hepatocellular carcinoma (HCC) tumors treated with radiotherapy in patients with chronic liver disease.

MATERIALS AND METHODS

Twenty-nine patients with viable tumor and 35 patients without viable tumor were enrolled. We assessed the signal intensity of viable tumor compared with irradiated liver on MRI and DWI. Signal intensity ratios and apparent diffusion coefficient (ADC) ratios of viable tumor to nonirradiated liver were also assessed on DWI with ADC maps. Two observers reviewed conventional MRI and combined MRI and DWI and rated them using a 5-point scale. Diagnostic performance was evaluated using a receiver operating characteristic (ROC) curve.

RESULTS

Viable tumors showed hyperintensity on T2-weighted and arterial phase images (16/29 [55.2%]) and hypointensity on portal (22/29 [75.9%]), 3-minute late (19/29 [65.5%]), and hepatobiliary phase (23/29 [79.3%]) images. Twenty-seven (93.1%) viable tumors showed hyperintensity on DWI and hypointensity on ADC maps. Mean signal intensity ratios and ADC ratios of viable tumor on DWI with ADC maps were significantly higher and lower than those of irradiated liver. Diagnostic performance (area under the ROC curve) improved significantly after adding DWI, and interobserver agreement was moderate for conventional MRI (κ = 0.450) and good after adding DWI (κ = 0.748).

CONCLUSION

Adding DWI to conventional MRI can improve the detection of viable HCC tumors treated with radiotherapy compared to conventional MRI alone.

Transcatheter arterial chemoembolization based on hepatic hemodynamics for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer-related deaths in the world. The Barcelona Clinic Liver Cancer (BCLC) classification has recently emerged as the standard classification system for clinical management of patients with HCC. According to the BCLC staging system, curative therapies (resection, transplantation, and percutaneous ablation) can improve survival in HCC patients diagnosed at an early stage and offer potential long-term curative effects. Patients with intermediate-stage HCC benefit from transcatheter arterial chemoembolization (TACE), and those diagnosed at an advanced stage receive sorafenib, a multikinase inhibitor, or conservative therapy. Most patients receive palliative or conservative therapy only, and approximately 50% of patients with HCC are candidates for systemic therapy. TACE is often recommended for advanced-stage HCC patients all over the world because these patients desire therapy that is more effective than systemic chemotherapy or conservative treatment. This paper aims to summarize both the published data and important ongoing studies for TACE and to discuss technical improvements in TACE for advanced-stage HCC.

The safety and efficacy of ablative techniques adjacent to the hepatic vasculature and biliary system

Ablative techniques may provide an alternative to resection in treating awkwardly placed hepatic malignancy adjacent to major vascular and biliary structures. The heat-sink effect may reduce efficacy adjacent to major vascular structures. Vascular occlusion improves efficacy but is associated with increased vascular and biliary complications. The safety and efficacy of ablation in these situations remain to be defined. Further studies comparing both safety and efficacy are needed.

Iodized oil accumulation in hypervascular hepatocellular carcinoma after transcatheter arterial chemoembolization: comparison of imaging findings with CT during hepatic arteriography

PURPOSE

To compare the degree of tumor enhancement seen on computed tomography (CT) during hepatic arteriography (CT/HA) performed before transcatheter arterial chemoembolization (TACE) versus that determined based on the accumulation of iodized oil seen on CT images obtained after TACE in patients with hypervascular hepatocellular carcinoma (HCC) and evaluate the discrepancy in findings between the two imaging modalities (more or less oil accumulation after TACE compared with enhancement on CT/HA).

MATERIALS AND METHODS

CT/HA, TACE, and iodized oil CT after TACE were performed in 69 patients with 83 hypervascular HCCs with use of an interventional CT system. The degree of contrast enhancement of the lesion on CT/HA and the iodized oil accumulation on unenhanced CT after TACE were compared.

RESULTS

Among 83 HCCs, the degree of enhancement on CT/HA before TACE corresponded to the iodized oil accumulation on CT in 56 (67.5%). Fifteen of 83 HCCs (18%) showed incomplete or poor accumulation of iodized oil despite good enhancement on CT/HA images. Twelve of 83 HCCs (14.5%) showed moderate or complete accumulation of iodized oil despite poor or no enhancement on CT/HA images. In particular, in two patients with occluded portal veins, iodized oil did not accumulate in the tumor despite good visualization on CT/HA.

CONCLUSIONS

Although iodized oil accumulation in hypervascular HCCs correlates with the degree of lesion enhancement on CT/HA in most cases, a discrepancy may occur in a substantial number of cases, which likely affects the prediction of therapeutic effects in hypervascular HCCs.

Haemodynamic changes in the liver under balloon occlusion of a portal vein branch: evaluation with single-level dynamic computed tomography during hepatic arteriography

AIM

To assess haemodynamic changes in the liver under temporary occlusion of an intrahepatic portal vein.

MATERIALS AND METHODS

Between February 2000 and October 2004, 16 patients with hepatobiliary disease underwent single-level dynamic computed tomography during hepatic arteriography (SLD-CTHA) under temporary balloon occlusion of an intrahepatic portal vein. All patients needed percutaneous transhepatic portography for therapy of their disease. SLD-CTHA was undertaken to clarify the time-attenuation curve influenced by portal vein occlusion, and it was performed continuously over a period of 30s. The difference in absolute attenuation of the liver parenchyma in segments with occluded and non-occluded portal vein branches was determined by means of the CT number, and the difference in absolute attenuation of the occluded and non-occluded portal veins themselves was also evaluated.

RESULTS

SLD-CTHA demonstrated a demarcated hyperattenuation area in the corresponding distribution of the occluded portal vein branch. The attenuation of the liver parenchyma supplied by the occluded portal vein was significantly higher than that in the non-occluded area (p<0.01). The balloon-occluded portal branch enhancement in 15 of 16 cases (94%) appears due to arterio-portal communications. Failure to evaluate a remaining case for portal branch enhancement was due to absence of a visualized portal branch in the section.

CONCLUSION

Under temporary occlusion of an intrahepatic portal vein, hepatic angiography produced enhancement of the occluded portal branches and their corresponding parenchymal distribution; this finding is considered consistent with the presence of arterio-portal communications.

Hepatic Venous Congestion After Right-lobe Living-donor Liver Transplantation

PURPOSE

To describe and determine the additional value of delayed-phase imaging of hepatic venous congestion after living-donor liver transplantation.

MATERIALS AND METHODS

Twenty-eight patients who had surgical ligation of the middle hepatic vein (HV) in living-donor liver transplantation underwent 3-phase computed tomography scans. Two radiologists analyzed in consensus the presence and pattern of the hepatic attenuation difference and the opacification of the HV in the congested areas of the liver during each phase of the initial and follow-up computed tomography scanning. The imaging findings were correlated with the serum bilirubin level.

RESULTS

Opacification of the HV was observed more frequently in 22 (92%) of 24 hyperattenuating areas on delayed-phase (DP) scans than in 2 (50%) of 4 hypoattenuating areas in the congested areas of the liver. Patients with persistent hypoattenuatation in the congested areas on all phases (14%) showed significantly persistent hyperbilirubinemia after postoperative 4 weeks and showed a higher mortality rate (50%) than did the other patients with hyperattenuation on DP scans.

CONCLUSIONS

A hypoattenuating area of the liver during DP scans indicates severe hepatic congestion and is correlated with hyperbilirubinemia and a high mortality rate.

Branching patterns and drainage territories of the middle hepatic vein in computer-simulated right living-donor hepatectomies

Full right hepatic grafts are most frequently used for adult-to-adult living donor liver transplantation (LDLT). One of the major problems is venous drainage of segments 5 and 8. Thus, this study was designed to provide information on venous drainage of right liver lobes for operation-planning. Fifty-six CT data sets from routine clinical imaging were evaluated retrospectively using a liver operation-planning system. We defined and analyzed venous drainage segments and the impact of anatomic variations of the middle hepatic vein (MHV) on venous outflow from segments 5 and 8. MHV variations led to significant shifts of segment 5 drainage between the middle and right hepatic vein. In cases with the most frequent MHV branching pattern (n = 33), a virtual hepatectomy closely right to the MHV intersected drainage vessels that provided drainage for 30% of the potential graft, not taking into account potential veno-venous shunts. In individuals with inferior MHV branches that extend far into segments 5 and 6 (n = 10), the overall graft volume at risk of impaired venous drainage increased by 5% (p < 0.001). If this is confirmed in clinical trials and correlated with intraoperative findings, the use of liver operation-planning systems would be beneficial to improve overall outcome after right lobe LDLT.

Hepatic venous congestion after living donor liver transplantation with right lobe graft: two-phase CT findings

PURPOSE

To describe and determine clinical importance of two-phase computed tomographic (CT) findings of hepatic venous congestion after living donor liver transplantation (LDLT) with right lobe graft.

MATERIALS AND METHODS

Forty-eight patients underwent two-phase (hepatic arterial phase and portal venous phase [PVP]) CT at 1, 2, and 4 weeks after LDLT. Images were evaluated for hepatic attenuation difference in areas of hepatic venous congestion, opacification of hepatic and peripheral portal veins in those areas, and changes in findings at follow-up CT. CT findings were correlated with serum bilirubin level. Fisher exact test and mixed model were applied. Histopathologic specimens were obtained in six patients.

RESULTS

Thirty patients (62%) had attenuation difference in segments V and VIII of right lobe transplant at initial CT scanning. Opacification of hepatic or peripheral portal veins was seen in 17 (63%) and 27 (100%) hyperattenuating areas of congestion during PVP and in none and three (19%) of 16 hypoattenuating areas, respectively. At 4-week follow-up CT, attenuation difference decreased in volume in 11 of 16 patients with hypoattenuation during PVP. All 14 patients with hyperattenuation showed no change in volume, but attenuation difference had decreased or disappeared. Histopathologic specimens showed evidence of hepatic venous congestion in all six patients. Hypoattenuation was seen at PVP CT in all three patients with severe hepatic venous congestion at histopathologic examination. Serum bilirubin level was significantly different between patients with hypoattenuation and those with hyperattenuation during PVP (P =.035) and between patients with hypoattenuation and those without attenuation difference (P =.009).

CONCLUSION

Areas possibly related to hepatic venous congestion after LDLT have variable attenuation at CT; decreased enhancement during PVP correlates with increased postoperative serum bilirubin level, which indicates severity of hepatic venous congestion.

Effects of prostaglandin E(1) injection through the superior mesenteric artery on the hemodynamics of hepatocellular carcinoma

OBJECTIVE

The purpose of our study was to assess the effects of portal blood flow on contrast enhancement in hepatocellular carcinoma lesions on CT hepatic arteriography.

SUBJECTS AND METHODS

We examined 43 tumors in 39 patients who simultaneously underwent CT during arterial portography and CT hepatic arteriography for examination of liver tumors and then CT hepatic arteriography with prostaglandin E(1) injection via the superior mesenteric artery. All lesions pathologically confirmed to be hepatocellular carcinomas exhibited portal perfusion defects on CT during arterial portography. Changes in CT attenuation, size, and shape of liver tumors visualized on CT hepatic arteriography after intraarterial injection of prostaglandin E(1) were studied. In addition, changes in CT attenuation of the liver parenchyma surrounding the tumor were measured.

RESULTS

The CT attenuation increased significantly after injection of prostaglandin E(1) in 91% (39/43) of the lesions (mean increase from 176.4 to 206.6 H; p = 0.0006, paired t test). The size and shape of the enhanced area generally did not change. The CT attenuation of the liver parenchyma surrounding each liver tumor significantly decreased in 58% (25/43) of the hepatocellular carcinoma lesions (mean decrease from 94.8 to 92.0 H; p = 0.0166, paired t test) and lesion conspicuity increased in 91% (39/43) of the tumors.

CONCLUSION

Lesion conspicuity on CT hepatic arteriography between hepatocellular carcinoma and the surrounding liver parenchyma increased because of greater portal perfusion after the prostaglandin E(1) injection.

Altered hepatic hemodynamics caused by temporary occlusion of the right hepatic vein: evaluation with Doppler US in 14 patients

PURPOSE

To evaluate with Doppler ultrasonography (US) the altered hepatic hemodynamics caused by temporary occlusion of the right hepatic vein.

MATERIALS AND METHODS

The study group consisted of 14 patients being considered for hepatic arterial infusion or transarterial embolization. In all patients, maximum peak velocity of the blood flow in the right portal vein was measured with Doppler US before and during the occlusion of the right hepatic vein. In 13 patients, color Doppler US was performed to evaluate Doppler signal in the portal venous branch in the occluded area before and during occlusion. Average peak velocity in the right hepatic artery in eight patients was measured by using a transducer-tipped guide wire before and during occlusion.

RESULTS

Maximum peak velocity of the right portal vein significantly decreased with occlusion (P <.01). Hepatic venous occlusion changed the Doppler signal in the portal venous branch in the occluded area from hepatopetal to no signal in 10 patients; to weakened hepatopetal in two; and to hepatofugal in one. Average peak velocity of the right hepatic artery showed a decrease or plateau for 15-30 seconds after the start of occlusion and then a rapid increase to reach a plateau at around 75-90 seconds, with 1.5-2 times as much velocity as that before occlusion.

CONCLUSION

Increase in hepatic arterial velocity is accompanied by a decrease in the portal velocity with temporary occlusion of the right hepatic vein; the expected increased drainage through the portal vein was almost undetectable.

Microwave coagulation therapy with interruption of hepatic blood in- or outflow: an experimental study

PURPOSE

To determine how interruption of hepatic blood in- or outflow affects the coagulation diameter of microwave coagulation therapy (MCT) in the liver.

MATERIALS AND METHODS

Laparotomic MCT at 60 W for 1 minute was performed in 11 Landrace pigs. MCT was performed under six different conditions: without occlusion (Group N; in seven lobes of seven pigs); with occlusion of the hepatic artery (Group A; in five lobes of five pigs); with occlusion of the portal vein (Group P; in five lobes of five pigs); with occlusion of the hepatic artery and portal vein (Group AP; in six lobes of six pigs); with occlusion of the hepatic vein (Group V; in five lobes of four pigs); and with occlusion of the hepatic artery and vein (Group AV; in seven lobes of seven pigs). The maximum diameters for each group were compared.

RESULTS

The coagulation diameters (mean +/- SD) were 8.5 mm +/- 2.0, 10.0 mm +/- 1.6, 14.3 mm +/- 2.5, 14.4 mm +/- 2.4, 13.0 mm +/- 0.8, and 14.4 mm +/- 1.5 for Groups N, A, P, AP, V, and AV, respectively. The coagulation diameters for groups P, AP, V, and AV were statistically larger than those for groups N and A (P < .05). There was no significant difference between the coagulation diameters of Groups P, AP, V, and AV.

CONCLUSION

The coagulation diameter depends mainly on the portal venous flow. In addition of direct interruption of the portal vein, interruption of the hepatic vein can also result in a substantial increase in the coagulation diameter.

Recurrent hepatocellular carcinoma versus radiation-induced hepatic injury: differential diagnosis with MR imaging

The objective of this study was to assess the value of MR imaging in the differentiation between a recurrent hepatocellular carcinoma (HCC) and a radiation-induced hepatic injury. Nine male patients with suspected recurrence after radiotherapy for HCC underwent T(2)-, T(1)-weighted imaging and Gd-DTPA enhanced dynamic studies. T(2) relaxation times, signal intensity ratios in T(1)-weighted images (WI) and the relative enhancement of the dynamic study were calculated. Recurrent tumors and the irradiated area showed similar image characteristics: hypointense in T(1)-WI and hyperintense in T(2)-WI. T(2) values and signal intensity ratios in the T(1)-WI were not significantly different. In the gadolinium-enhanced dynamic study, a recurrent HCC showed early enhancement, followed by a rapid washout. However, the irradiated liver parenchyma showed hyperintensity from an early phase, and contrast enhancement tended to be more prominent and prolonged at the end of the dynamic studies. The characteristic findings of the dynamic MR study enable us to distinguish between a recurrent HCC and a radiation-induced hepatic injury.