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.     

Use of a Doppler guide wire for intravascular blood flow measurements: a validation study for potential neurologic endovascular applications.

PURPOSETo conduct a validation study of a Doppler guide wire for potential neuroendovascular applications.METHODSA 12-MHz, 0.018-inch Doppler guide wire was evaluated in eight swine under various blood flow conditions using two types of in vivo cerebrovascular models (physiologic and arteriovenous shunting). Flow conditions were mechanically and pharmacologically altered. Doppler average peak velocity was compared with volumetric blood flow, and flow profile corrections were calculated and analyzed. Qualitative aspects of the Doppler guide wire spectra were also assessed.RESULTSPlots of average peak velocity versus volumetric blood flow showed excellent linear relationships (r2 > 0.94), which were maintained at high flow conditions (average peak velocity, 99 to 236 cm/sec; volumetric blood flow, 392 to 889 mL/min). Values of flow profile correction varied from 0.43 to 0.94 and showed no consistent relationship to changes in volumetric blood flow.CONCLUSIONSThe excellent correlation between average peak velocity and volumetric blood flow over a wide range of blood flow conditions and the additional qualitative information of the Doppler guide wire spectra establish a foundation for clinical implementation. The unpredictable variations of flow profile corrections remain obstacles for calculating volumetric blood flow based on Doppler guide wire average peak velocity.     

Doppler sonography of hepatic arterial blood flow velocity after percutaneous transhepatic portal vein embolization

OBJECTIVE: This study was conducted to elucidate the changes in hepatic arterial blood flow after portal vein embolization. SUBJECTS AND METHODS: We prospectively measured the flow velocity and resistive index of the common, right, and left hepatic arteries, using Doppler sonography, in 21 patients who underwent embolization of the right portal vein. The measurements were performed before and 1, 3, 5, 7, and 14 days after embolization. We assessed the changes in liver volume with a volumetric study using CT. RESULTS: After embolization, flow velocity in the common hepatic artery increased significantly (p < 0.0001). Flow velocity in the right hepatic artery also increased significantly (p < 0.0001), with a significant decrease in resistive index (p < 0.0001). The flow velocity and resistive index of the left hepatic artery were unchanged. The increase in flow velocity in the right hepatic artery significantly correlated with that in the common hepatic artery (r = 0.514, p < 0.05). The calculated volume of the embolized right hepatic lobe significantly (p < 0.0001) decreased, from 685 +/- 32 cm(3) before embolization to 568 +/- 28 cm(3) after embolization. The atrophy rate of the right hepatic lobe significantly correlated with the increase in flow velocity in the right hepatic artery (r = 0.700, p < 0.0005). CONCLUSION: Portal vein embolization induces an increase in hepatic arterial blood flow velocity in the embolized hepatic segments, resulting from an increase in common hepatic arterial flow, but not from a steal phenomenon due to decreased hepatic arterial blood flow in the nonembolized hepatic segments. This observation may be explained by the simple mechanical effect of interposing a slower flowing stream (portal flow) in the path of a faster flowing stream (arterial flow).     

Forcible Intraarterial Injection of a Nonadhesive Liquid Embolic Agent under Microballoon Occlusion: Experimental Study in Swine Liver

PurposeTo evaluate the feasibility and effectiveness of transcatheter embolization by forcible intraarterial injection of a mixture of ethylene vinyl alcohol copolymer (EVAL) and ethanol under microballoon occlusion compared with conventional transcatheter arterial embolization methods in nontumoral swine liver.Materials and MethodsNine swine were divided into three groups: embolization with EVAL/ethanol mixture (EVAL group, n = 5), with ethiodized oil (ethiodized oil group, n = 2), and with microspheres (microspheres group, n = 2). Embolization was performed at the subsegmental hepatic artery. The EVAL/ethanol mixture was injected forcibly through a microcatheter with a balloon, which was inflated to prevent backflow of the mixture during the injection. Ethiodized oil or microspheres were injected into the artery using a microcatheter without balloon occlusion. Two animals of the EVAL group were euthanized immediately after embolization, and the distribution of EVAL was assessed microscopically. The remaining seven animals were euthanized 4 weeks after embolization, and the histopathologic changes were assessed.ResultsAll procedures were technically successful. EVAL occupied > 80% of the hepatic arterial, portal venous, and sinusoidal lumens after embolization. Ischemic coagulation necrosis was observed 4 weeks after embolization in the EVAL group. Parenchymal necrosis was not observed in the ethiodized oil and microspheres groups.ConclusionsTranscatheter embolization by forcible intraarterial injection of an EVAL/ethanol mixture under microballoon occlusion was feasible and achieved the simultaneous embolization of hepatic artery, portal vein, and sinusoids in swine liver, resulting in complete necrosis of the segment that received embolization.     

Transarterial Chemoembolization with Additional Cisplatin Infusion for Hepatocellular Carcinoma Invading the Hepatic Vein

PurposeTo evaluate retrospectively the efficacy of transarterial chemoembolization in patients with hepatocellular carcinoma (HCC) with hepatic vein invasion by comparing the results of conventional transarterial chemoembolization and modified transarterial chemoembolization.Materials and MethodsFrom January 2000 to December 2009, 107 patients with HCC and hepatic vein invasion and Child-Pugh class A were treated by transarterial chemoembolization. Modified transarterial chemoembolization (conventional transarterial chemoembolization followed by additional infusion of 50–100 mg of cisplatin) has been undertaken since 2005. Clinical and radiologic data were reviewed and analyzed retrospectively. The overall survival rates were obtained by the Kaplan-Meier method and compared by the log-rank test.ResultsConventional transarterial chemoembolization was performed in 60 patients, and modified transarterial chemoembolization was performed in 47 patients. No significant differences were observed in major complications between the groups. The median survival was longer in the modified group compared with the conventional group (9.7 mo, 95% confidence interval [CI], 4.3–15.1, vs 6.7 mo, 95% CI, 4.8–8.5; P = .047). By subgroup analysis, modified transarterial chemoembolization increased survival of patients with a diffuse tumor type (8.9 mo, 95% CI, 5.9–11.9, vs 3.8 mo, 95% CI, 2.5–5.0; P = .000) and patients without metastasis (20.9 mo, 95% CI, 12.2–29.5, vs 7.3 mo, 95% CI, 4.1–10.5; P = .005). Multivariate analysis identified three independent predictive factors for mortality: diffuse tumor type (P = .001), metastasis (P = .009), and modified transarterial chemoembolization protocol (P = .003).ConclusionsA survival benefit was suggested with transarterial chemoembolization with additional cisplatin infusion over conventional transarterial chemoembolization in patients with HCC invading the hepatic vein.     

Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor

Purpose

This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model.

Methods

All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 °C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 °C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection.

Results

After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group.

Conclusions

The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.     

Intravenous Vasopressin for the Prevention of Nontarget Gastrointestinal Embolization during Liver-directed Cancer Treatment: Experimental Study in a Porcine Model

PurposeThe aim of this study was to evaluate the potential for intravenous vasopressin to reduce the risk of nontarget gastrointestinal embolization during transcatheter liver-directed cancer therapies in a porcine model.Materials and MethodsAn angiographic catheter was used to select the celiac or common hepatic artery under fluoroscopic guidance in six anesthetized pigs. After angiography of the hepatic and splanchnic territories was performed, technetium-99m macroaggregated albumin (^99mTc-MAA) was injected through the catheter. Serial arteriograms were obtained before, every 5 minutes during, and after peripheral intravenous vasopressin infusion at 0.4 U/min for a minimum of 20 minutes. After 10 minutes of infusion, indium-111 (¹¹¹In)-MAA was injected through the arterial catheter. Quantitative comparisons of liver and gastrointestinal activity using dual-isotope single-photon emission computed tomography (SPECT)/CT imaging were performed.ResultsCatheter angiography demonstrated reduced blood flow to the splanchnic vasculature while maintaining blood flow through the hepatic arteries during vasopressin infusion. Angiographic findings correlated with the relative distribution of ^99mTc-MAA (before the vasopressin infusion) and ¹¹¹In-MAA (after the vasopressin infusion) on SPECT/CT. The increased ratio of liver to gastrointestinal tract activity during the vasopressin infusion was statistically significant (6.2:11.4, respectively; P = .018).ConclusionsIntravenous vasopressin reduces arterial blood flow to the splanchnic vasculature while preserving hepatic arterial blood flow in a healthy porcine model. Intraprocedural vasopressin administration has the potential to benefit liver-directed cancer therapies by enhancing tumor targeting as well as preventing the unintended delivery of bland embolic, chemoembolic, or radioembolic agents into the gastrointestinal vascular territories.     

Combination Therapies: Quantifying the Effects of Transarterial Embolization on Microwave Ablation Zones

Purpose

To quantify the effect of transarterial embolization on microwave (MW) ablations in an in vivo porcine liver model.

A Rat Model of Frozen Shoulder Demonstrating the Effect of Transcatheter Arterial Embolization on Angiography,Histopathology, and Physical Activity

PurposeTo assess the angiographic findings and the effects of transcatheter arterial embolization on physical activity and histopathology using a frozen shoulder rat model.Materials and MethodsFirst, the angiographic and histopathologic findings of rats in which the shoulder was immobilized with molding plaster for 6 weeks (n = 4) were compared to control rats with normal non-immobilized shoulders (n = 4). Next, a total of 16 frozen shoulder rats were divided into 2 groups. In the transcatheter arterial embolization group (n = 8), imipenem/cilastatin was injected into the left thoracoacromial artery. The changes of physical activity before and after procedures were evaluated and compared with a saline-injected control group (n = 8). Histopathologic findings were also compared between the 2 groups.ResultsAngiography revealed abnormal shoulder staining in all of the rats with a frozen shoulder. On histopathology, the numbers of microvessels and mononuclear inflammatory cells in the synovial membrane of the joint capsule were significantly higher compared with the control rats (both P = .03). In the transcatheter arterial embolization group, the running distance and speed were improved (P = .03 and P = .01, respectively), whereas there were no significant differences in the control group. The number of microvessels and mononuclear inflammatory cells in the transcatheter arterial embolization group were significantly lower than the control group (P = .002 and P = .001, respectively).ConclusionsThe rat frozen shoulder model revealed the development of neovascularization. Transcatheter arterial embolization decreased the number of blood vessels and inflammatory changes in the frozen shoulder and increased the moving distance and speed of the rats.     

Bariatric Arterial Embolization with Calibrated Radiopaque Microspheres and an Antireflux Catheter Suppresses Weight Gain and Appetite-Stimulating Hormones in Swine

PurposeTo examine safety and efficacy of bariatric arterial embolization (BAE) with x-ray–visible embolic microspheres (XEMs) and an antireflux catheter in swine.Material and MethodsBAE with selective infusion of XEMs (n = 6) or saline (n = 4, control) into gastric fundal arteries was performed under x-ray guidance. Weight and plasma hormone levels were measured at baseline and weekly for 4 weeks after embolization. Cone-beam CT images were acquired immediately after embolization and weekly for 4 weeks. Hormone-expressing cells in the stomach were assessed by immunohistochemical staining.ResultsBAE pigs lost weight 1 week after embolization followed by significantly impaired weight gain relative to control animals (14.3% vs 20.9% at 4 weeks, P = .03). Plasma ghrelin levels were significantly lower in BAE pigs than in control animals (1,221.6 pg/mL vs 1,706.2 pg/mL at 4 weeks, P < .01). XEMs were visible on x-ray and cone-beam CT during embolization, and radiopacity persisted over 4 weeks (165.5 HU at week 1 vs 158.5 HU at week 4, P = .9). Superficial mucosal ulcerations were noted in 1 of 6 BAE animals. Ghrelin-expressing cell counts were significantly lower in the gastric fundus (17.7 vs 36.8, P < .00001) and antrum (24.2 vs 46.3, P < .0001) of BAE pigs compared with control animals. Gastrin-expressing cell counts were markedly reduced in BAE pigs relative to control animals (98.5 vs 127.0, P < .02). Trichrome staining demonstrated significantly more fibrosis in BAE animals compared with control animals (13.8% vs 8.7%, P < .0001).ConclusionsXEMs enabled direct visualization of embolic material during and after embolization. BAE with XEMs and antireflux microcatheters was safe and effective.     

Chronic Hepatotoxicity in Patients with Metastatic Neuroendocrine Tumor: Transarterial Chemoembolization versus Transarterial Radioembolization

PurposeTo compare the manifestations of chronic liver injury following transarterial chemoembolization with those of transarterial radioembolization (TARE) in patients with neuroendocrine tumor (NET).Materials and MethodsThis study consisted of an Institutional Review Board-approved single-institution retrospective analysis of NET patients who received transarterial chemoembolization from 2006 to 2016 and TARE from 2005 to 2014 and survived at least 1 year from the initial treatment. Patients receiving only transarterial chemoembolization (n = 63) or TARE (n = 28) were evaluated for the presence or absence of durable hepatic toxicities occurring at least 6 months after initial treatment. The definitions and grades of liver injury were adapted from Common Terminology Criteria for Adverse Events version 4.0 and were characterized by the presence of laboratory or clinical toxicities of Grade 3 or above.ResultsChronic hepatic toxicity occurred in 14 of 63 transarterial chemoembolization patients (22%) with a total of 26 Grade 3-4 events, in whom elevation of bilirubin was the most common toxicity, compared to 8 of 28 TARE patients (29%) with a total of 16 Grade 3-4 and 2 Grade 5 events, in whom ascites were the most frequent toxicity. There were more laboratory toxicities in the transarterial chemoembolization group (65% vs 38%, P = .11) and fewer Grade 4–5 injuries (6% vs 27% of patients, P = .06). There was also a significantly higher number of patients who experienced intrahepatic progression of disease in the transarterial chemoembolization cohort than in the TARE patients (75% vs 43%, respectively; P = .005).ConclusionsDelayed hepatotoxicity from transarterial chemoembolization and TARE occurred in 22% and 29% of patients, respectively, from 6 months to several years following treatment. Transarterial chemoembolization-related toxicities on average were less severe and manifested primarily as laboratory derangements, compared to TARE toxicities which consisted of clinical hepatic decompensation.     

Follow-up after embolization of ruptured intracranial aneurysms: A prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography

Introduction

To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment.

Methods

Seventy-two consecutive patients were examined 3?months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined.

Results

The sensitivity and specificity of residual flow detection ranged from 84.6?% (2D-DSA and TOF-MRA) to 92.3?% (3D-DSA) and from 91.3?% (TOF-MRA) to 97.8?% (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen??s kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P?<?0.05, ROC analysis). The intraobserver agreement was very good for all techniques (???=?0.80?C0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA (???=?0.72?C0.94).

Conclusion

Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization.     

Hepatic Artery Infusion Chemotherapy Using Fluorouracil,Leucovorin, and Oxaliplatin versus Transarterial Chemoembolization as Initial Treatment for Locally Advanced Hepatocellular Carcinoma: A Propensity Score–Matching Analysis

PurposeTo compare the efficacy and safety of hepatic arterial infusion chemotherapy (HAIC) with a modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX) regimen with that of transarterial chemoembolization as a locoregional treatment for patients with locally advanced hepatocellular carcinoma (HCC).MethodsThis retrospective study included adult patients with locally advanced HCC who received first-line treatment with either HAIC-mFOLFOX or conventional transarterial chemoembolization monotherapy from January 2015 to December 2016. The outcomes, including tumor response rates, evaluated via imaging assessment using the modified response evaluation criteria in solid tumors; overall survival; progression-free survival; and safety, were compared. The propensity score–matching methodology was used to reduce the influence of confounding factors on the outcomes.ResultsThe study included 131 patients with locally advanced HCC who underwent transarterial chemoembolization and 101 who received HAIC-mFOLFOX as initial treatment. After propensity score matching (n = 67 in each group), patients who received HAIC-mFOLFOX had a higher objective response rate (43.3% vs 13.4%, P = .001), longer median overall survival (13.9 vs 6.0 months, P < .001), and longer median progression-free survival (6.4 vs 2.8 months, P = .001) than those who underwent transarterial chemoembolization. The survival benefit with HAIC-mFOLFOX was strengthened in patients with HCC with vascular invasion (hazard ratio: 0.379; 95% confidence interval: 0.237–0.607). HAIC-mFOLFOX was associated with lower incidences of severe adverse events (8.9% vs 22.9%) and liver toxicity than transarterial chemoembolization.ConclusionsCompared with transarterial chemoembolization, HAIC-mFOLFOX is a potentially safer and more effective locoregional therapy for patients with locally advanced HCC.     

4D Flow MR Imaging to Improve Microwave Ablation Prediction Models: A Feasibility Study in an In Vivo Porcine Liver

PurposeTo characterize the effect of hepatic vessel flow using 4-dimensional (4D) flow magnetic resonance (MR) imaging and correlate their effect on microwave ablation volumes in an in vivo non-cirrhotic porcine liver model.Materials and MethodsMicrowave ablation antennas were placed under ultrasound guidance in each liver lobe of swine (n = 3 in each animal) for a total of 9 ablations. Pre- and post-ablation 4D flow MR imaging was acquired to quantify flow changes in the hepatic vasculature. Flow measurements, along with encompassed vessel size and vessel-antenna spacing, were then correlated with final ablation volume from segmented MR images.ResultsThe linear regression model demonstrated that the preablation measurement of encompassed hepatic vein size (β = –0.80 ± 0.25, 95% confidence interval [CI] –1.15 to –0.22; P = .02) was significantly correlated to final ablation zone volume. The addition of hepatic vein flow rate found via 4D flow MRI (β = –0.83 ± 0.65, 95% CI –2.50 to 0.84; P = .26), and distance from antenna to hepatic vein (β = 0.26 ± 0.26, 95% CI –0.40 to 0.92; P = .36) improved the model accuracy but not significantly so (multivariate adjusted R² = 0.70 vs univariate (vessel size) adjusted R² = 0.63, P = .24).ConclusionsHepatic vein size in an encompassed ablation zone was found to be significantly correlated with final ablation zone volume. Although the univariate 4D flow MR imaging-acquired measurements alone were not found to be statistically significant, its addition to hepatic vein size improved the accuracy of the ablation volume regression model. Pre-ablation 4D flow MR imaging of the liver may assist in prospectively optimizing thermal ablation treatment.     

Hepatic Blood Volume Imaging with the Use of Flat-Detector CT Perfusion in the Angiography Suite: Comparison with Results of Conventional Multislice CT Perfusion

PurposeTo prospectively determine the feasibility of flat-detector (FD) computed tomography (CT) perfusion to measure hepatic blood volume (BV) in the angiography suite in patients with hepatocellular carcinoma (HCC).Materials and MethodsTwenty patients with HCC were investigated with conventional multislice and FD CT perfusion. CT perfusion was carried out on a multislice CT scanner, and FD CT perfusion was performed on a C-arm angiographic system, before transarterial chemoembolization procedures. BV values of conventional and FD CT perfusion were measured within tumors and liver parenchyma. The arterial perfusion portion of CT perfusion BV was extracted from CT perfusion BV by multiplying it by a hepatic perfusion index. Relative values (RVs) for CT perfusion arterial BV and FD CT perfusion BV (FD BV) were defined by dividing BV of tumor by BV of parenchyma. Relationships between BV and RV values of these two techniques were analyzed.ResultsIn all patients, both perfusion procedures were technically successful, and all 33 HCCs larger than 10 mm were identified with both imaging methods. There were strong correlations between the absolute values of FD BV and CT perfusion arterial BV (tumor, r = 0.903; parenchyma, r = 0.920; both P < .001). Bland–Altman analysis showed a mean difference of −0.15 ± 0.24 between RVs for CT perfusion arterial BV and FD BV.ConclusionsThe feasibility of FD CT perfusion to assess BV values of liver tumor and surrounding parenchyma in the angiographic suite was demonstrated.     

Comparison of Soluble Gelatin Sponge Particles and Tris-acryl Gelatin Microspheres for Bariatric Arterial Embolization in Swine

The purpose of this study was to compare complications and the number of ghrelin-expressing cells (GECs) after bariatric arterial embolization (BAE) using soluble gelatin sponge particles (SGSs) or tris-acryl gelatin microspheres (MSs) in swine. Twelve swine underwent embolization of gastric fundal arteries with SGSs (n = 4) or MSs (n = 4) or underwent saline infusion (n = 4, control group). One week later, the number of gastric ulcers and the percentage of GECs were compared among the 3 groups. There were no ulcers in the SGS and control groups. Two swine in the MS group had 4 large ulcers (12–50 mm in size). The mean percentages of GECs were significantly lower in the SGS (2.7% ± 0.9%) and MS (2.5% ± 1.0%) groups compared with the control group (3.7% ± 1.3%; P = .038 and P = .016, respectively). SGSs may be safer than MSs for BAE while inducing a similar reduction of GECs in swine.     

Assessment of Reverse Flow as a Means of Cerebral Protection during Carotid Artery Stent Placement with Diffusion-weighted and Transcranial Doppler Imaging

PurposeTo assess the effectiveness of flow reversal as an alternative means of cerebral protection by using transcranial Doppler recordings and diffusion-weighted imaging (DWI) as surrogate markers of brain injury.Materials and MethodsEighteen patients with symptomatic carotid artery disease were recruited. Magnetic resonance imaging was performed before the intervention and at 3 and 24 hours and 30 days after the intervention to detect new ischemic lesions with DWI. Transcranial Doppler recordings were made during the procedure to assess for microembolic signals (MESs). Data were compared against data from a historical control cohort of patients who underwent CAS placement with or without filter protection (n = 15 each) under the same protocol in a different study.ResultsThere were fewer periprocedural new lesions on DWI in the reverse-flow cohort compared with the historical control cohort with filter protection (P = .084). Reverse flow revealed significantly fewer MESs during the whole procedure compared with the filter-protected group (P = .01) but not the unprotected group (P = .55). There was a marked decrease in MES counts for reverse flow protection during the embologenic stages of the procedure (P = .004).ConclusionsUse of the reverse flow device was associated with fewer overall lesions on DWI and proportionately fewer positive scans compared with the use of filter-type devices (P = .08, not significant). Transcranial Doppler recordings demonstrated a significant reduction in embolization to the brain during carotid artery stent placement with the use of reverse-flow cerebral protection.     

Histopathologic and Immunohistochemical Sequelae of Bariatric Embolization in a Porcine Model

PurposeTo evaluate the histopathologic sequelae of bariatric embolization on the gastric mucosa and to correlate with immunohistochemical evaluation of the gastric fundus, antrum, and duodenum.Materials and MethodsThis study was performed on 12 swine stomach and duodenum specimens after necropsy. Of the 12 swine, 6 had previously undergone bariatric embolization of the gastric fundus, and the 6 control swine had undergone a sham procedure with saline. Gross pathologic, histopathologic, and immunohistochemical examinations of the stomach and duodenum were performed. Specifically, mucosal integrity, fibrosis, ghrelin-expressing cells, and gastrin-expressing cells were assessed.ResultsGross and histopathologic evaluation of treatment animals showed healing or healed mucosal ulcers in 50% of animals, with gastritis in 100% of treatment animals and in five of six control animals. The ghrelin-immunoreactive mean cell density was significantly lower in the gastric fundus in the treated animals compared with control animals (15.3 vs 22.0, P < .01) but similar in the gastric antrum (9.3 vs 14.3, P = .08) and duodenum (8.5 vs 8.6, P = .89). The gastrin-expressing cell density was significantly lower in the antrum of treated animals compared with control animals (82.2 vs 126.4, P = .03). A trend toward increased fibrosis was suggested in the gastric fundus of treated animals compared with controls (P = .07).ConclusionsBariatric embolization resulted in a significant reduction in ghrelin-expressing cells in the gastric fundus without evidence of upregulation of ghrelin-expressing cells in the duodenum. Healing ulcerations in half of treated animals underscores the need for additional refinement of this procedure.     

Early Treatment Response Evaluation after Yttrium-90 Radioembolization of Liver Malignancy with CT Perfusion

PurposeTo evaluate computed tomography (CT) perfusion for assessment of early treatment response after transarterial radioembolization of patients with liver malignancy.Materials and MethodsDynamic contrast-enhanced CT liver perfusion was performed before and 4 weeks after transarterial radioembolization in 40 patients (25 men and 15 women; mean age, 64 y ± 11; range, 35–80 y) with liver metastases (n = 27) or hepatocellular carcinoma (HCC) (n = 13). Arterial perfusion (AP) of tumors derived from CT perfusion and tumor diameters were measured on CT perfusion before and after transarterial radioembolization. Success of transarterial radioembolization was evaluated on morphologic follow-up imaging (median follow-up time, 4 mo) based on Response Evaluation Criteria in Solid Tumors (Version 1.1). CT perfusion parameters before and after transarterial radioembolization for different response groups were compared. Kaplan-Meier curves were plotted to illustrate overall 1-year survival rates.ResultsLiver metastases showed significant differences in AP before and after transarterial radioembolization in responders (P < .05) but not in nonresponders (P = .164). In HCC, AP values before and after transarterial radioembolization were not significantly different in responders and nonresponders (P = .180 and P = .052). Tumor diameters were not significantly different on CT perfusion before and after transarterial radioembolization in responders and nonresponders with liver metastases and HCC (P = .654, P = .968, P = .148, P = .164). In patients with significant decrease of AP in liver metastases after transarterial radioembolization, 1-year overall survival was significantly higher than in patients showing no reduction of AP.ConclusionsCT perfusion showed early reduction of AP in liver metastases responding to transarterial radioembolization; tumor diameter remained unchanged early after treatment. No significant early treatment response to transarterial radioembolization was found in patients with HCC. In patients with liver metastases, a decrease of AP after transarterial radioembolization was associated with a higher 1-year overall survival rate.     

Benefits and Problems of Transarterial Therapy in Patients with Hepatocellular Carcinoma and Chronic Kidney Disease

PurposeTo evaluate the feasibility of transarterial therapy (transcatheter arterial chemoembolization and transcatheter arterial infusion) for patients with hepatocellular carcinoma and chronic kidney disease (CKD).Materials and MethodsThe study enrolled 35 patients who received transarterial therapy. The patients were classified into a CKD group (n = 10 nondialysis chronic kidney disease [NDCKD] and n = 9 end-stage renal disease [ESRD]) or a non-CKD group (n = 16). The survival rates between the two groups were compared using two different starting points: (a) from initial diagnosis of hepatocellular carcinoma and (b) from enrollment in the study. The tolerance of transarterial therapy in patients with CKD was evaluated by comparing the incidence of major adverse events.ResultsThe 2-year and 5-year survival rates from initial diagnosis were 83.9% and 53.8% in the CKD group and 70.1% and 40.4% in the non-CKD group (P = .478). The corresponding 3-year survival rate from enrollment in the two groups was 25.6% and 41.2%, respectively (P = .995). The 2-year and 5-year survival rates from initial diagnosis were 70.1% and 40.4% in the non-CKD group, 90.0% and 39.4% in NDCKD patients, and 76.2% and 76.2% in ESRD patients (P = .380). The corresponding 2-year survival rates from enrollment in these groups were 54.9%, 48.0%, and 48.6% (P = .943). Severe contrast-induced nephropathy (n = 3) and late-onset death caused by cholesterol crystal embolism (n = 1) were observed in the NDCKD group.ConclusionsTranscatheter arterial chemoembolization is feasible in patients with CKD by instituting periprocedural hemodialysis with similar 2-year and 5-year survival compared with patients without CKD.