Randomized controlled trial for the efficacy of hepatic arterial occlusion during radiofrequency ablation for small hepatocellular carcinoma--direct ablative effects and a long-term outcome.

OBJECTIVE: To evaluate the efficacy of temporary balloon arterial occlusion during radiofrequency ablation (RFA), randomized controlled trial was performed. METHODS: Twenty patients with hypervascular hepatocellular carcinoma measuring 相似文献   

Radiofrequency ablation during continuous saline infusion can extend ablation margins

AIM:To determine whether fluid injection during radiofrequency ablation(RFA) can increase the coagulation area.METHODS:Bovine liver(1-2 kg) was placed on an aluminum tray with a return electrode affixed to the base,and the liver was punctured by an expandable electrode.During RFA,5% glucose;50% glucose;or saline fluid was infused continuously at a rate of 1.0 mL/min through the infusion line connected to the infusion port.The area and volume of the thermocoagulated region of bovine liver were determined after RFA.The Joule heat generated was determined from the temporal change in output during the RFA experiment.RESULTS:No liquid infusion was 17.3 ± 1.6 mL,similar to the volume of a 3-cm diameter sphere(14.1 mL).Mean thermocoagulated volume was significantly larger with continuous infusion of saline(29.3 ± 3.3 mL) than with 5% glucose(21.4 ± 2.2 mL),50%glucose(16.5 ± 0.9 mL) or no liquid infusion(17.3 ± 1.6 mL).The ablated volume for RFA with saline was approximately 1.7-times greater than for RFA with no liquid infusion,representing a significant difference between these two conditions.Total Joule heat generated during RFA was highest with saline,and lowest with 50% glucose.CONCLUSION:RFA with continuous saline infusion achieves a large ablation zone,and may help inhibit local recurrence by obtaining sufficient ablation margins.RFA during continuous saline infusion can extend ablation margins,and may be prevent local recurrence.     

Ablative margin states by magnetic resonance imaging with ferucarbotran in radiofrequency ablation for hepatocellular carcinoma can predict local tumor progression

Background

Our aim was to determine how well ablative margin (AM) grading assessed by magnetic resonance imaging (MRI) with ferucarbotran administered prior to radiofrequency ablation (RFA) predicts local tumor progression in comparison with enhanced computed tomography (CT).

Methods

101 hepatocellular carcinomas were treated by RFA after ferucarbotran administration. We performed T2*-weighted MRI after 1 week and enhanced CT after 1 month. The assessment was categorized in three grades: AM(+): high-intensity area with continuous low-intensity rim; AM zero: high-intensity area with discontinuous low-intensity rim; and AM(?): high-intensity area extending beyond the low-intensity rim.

Results

AM(+), AM zero, AM(?) and indeterminable were found in 47, 36, 8 and 10 nodules, respectively. The overall agreement rate between MRI and enhanced CT for the diagnosis of AM was 71.3 %. The κ coefficient was 0.523 (p < 0.001), indicating moderate agreement. Multivariate logistic regression showed that a significant factor for the achievement of AM(+) on MRI was only segment location (odds ratio 5.9, non-segment 4 + 8 vs. segment 4 + 8). The cumulative local tumor progression rates (4.4, 7.6, and 7.6 % in 1, 2, and 3 years) in 47 AM(+) nodules were significantly lower than those (13.9, 33.4, and 41.8 % in 1, 2, and 3 years) in 36 AM zero nodules. A multivariate Cox proportional hazards model identified contiguous vessels (odds ratio 12.0) and AM(+) on MRI (odds ratio 0.19) as independent factors for local tumor progression.

Conclusion

AM assessment by MRI using ferucarbotran can predict local tumor progression after RFA and enable early and less invasive diagnosis.     

Comparison of therapeutic effects between radiofrequency ablation and percutaneous microwave coagulation therapy for small hepatocellular carcinomas

Background:  Although thermal ablation therapies have gained fairly wide acceptance as an effective treatment for small hepatocellular carcinoma (HCC), there have been only a few clinical studies comparing the response to radiofrequency ablation (RFA) and percutaneous microwave coagulation therapy (PMCT). We evaluated the therapeutic efficacy and safety of these two procedures for the treatment of small HCC measuring ≤ 2 cm in diameter.
Methods:  Thirty-four patients who had 37 nodules were treated by RFA and were compared with 49 patients (56 nodules) who underwent PMCT. Treatment was repeated until complete tumor necrosis was confirmed by contrast computed tomography (CT) scanning. The therapeutic efficacy and complications were retrospectively compared between the two procedures.
Results:  (i) There were significantly fewer treatment sessions ( P  < 0.001) in the RFA group than in the PMCT group, but the necrotic area was significantly larger ( P  < 0.001) in the former group. (ii) The local recurrence rate was significantly lower ( P  = 0.031) after RFA than after PMCT, although the ectopic recurrence rate showed no significant difference. (iii) The cumulative survival rate was significantly higher ( P  = 0.018) after RFA than after PMCT. (iv) The incidence of pain and fever after treatment was significantly higher in the PMCT group. Bile duct injury, pleural effusion, and ascites were also significantly more common in the PMCT group.
Conclusions:  RFA is more useful than PMCT for the treatment of small HCC because it is minimally invasive and achieves a low local recurrence rate, high survival rate, and extensive necrosis after only a few treatment sessions.     

Outcome of transarterial chemoembolization monotherapy, and in combination with percutaneous ethanol injection, or radiofrequency ablation therapy for hepatocellular carcinoma

Aim:  Hepatocellular carcinoma (HCC) is one of the most commonly occurring malignances worldwide. Curative therapies such as resection, percutaneous ethanol injection (PEI) and radiofrequency ablation (RFA) have been applied to patients with early-stage HCC. Patients with more advanced cancers require local or systemic therapies. We present the results of our retrospective review conducted to evaluate whether transarterial chemoembolization (TACE) alone and combined TACE with percutaneous ablation for HCC exhibited superior efficacy to palliative treatment.
Methods:  The effects of TACE and of the combined therapies (TACE + PEI or TACE + RFA) on the long-term survival rates were evaluated in 268 untreated HCC patients by various statistical analyses.
Results:  The cumulative survival rates in the TACE alone group were significantly superior to those in the palliative treatment group. Further, the cumulative survival rates in the combined TACE + PEI/RFA group were significantly superior to those in the TACE alone group. When the comparison among the groups was restricted to patients with two or three tumors fulfilling the Milan criteria, significantly greater prolongation of survival was observed in the combined TACE + PEI/RFA group than in the PEI/RFA alone group.
Conclusions:  The aforementioned treatment modalities yielded greater improvements of the survival rate and survival duration as compared to palliative treatment in HCC patients. Furthermore, in terms of the effect on the survival period, combined TACE + PEI/RFA therapy was more effective than TACE monotherapy, and also more effective than PEI or RFA monotherapy in cases with multiple tumors fulfilling the Milan criteria.     

Combination therapy of radiofrequency ablation and transarterial chemoembolization in recurrent hepatocellular carcinoma after hepatectomy compared with single treatment

Aim:  To assess the efficacy and safety of radiofrequency ablation (RFA) combined with transarterial chemoembolization (TACE) in recurrent hepatocellular carcinoma (HCC) after hepatectomy and to compare its outcome with a single modality.
Method:  We retrospectively studied 103 patients with recurrent HCCs after hepatectomy who were excluded from repeat hepatectomy. Of them, 81 patients were male and 22 were female (mean age 55.8 ± 10.7 years; range, 30–80 years). According to treatment modality, these patients were divided into three groups: RFA was used as the sole first-line anticancer treatment in 37 patients (RFA group); TACE was used as the sole first-line anticancer treatment in 35 patients (TACE group). RFA followed by TACE was performed in 31 patients (combination group). There was no significant difference in clinical material between the three groups. Indices including treatment success rate, intrahepatic recurrence rate and survival were obtained for analysis and comparison.
Results:  The treatment success rate of the combination group was significantly higher than that of the TACE group (93.5 vs. 68.6%, P  = 0.011). The intrahepatic recurrence rate of the combination group was significantly lower than that of the TACE group (20.7 vs 57.1%, P  = 0.002) and the RFA group (20.7 vs 43.2%, P  = 0.036). The overall 1-, 3- and 5-year survival rates were 73.9, 51.1 and 28.0% respectively in the RFA group; 65.8, 38.9 and 19.5% respectively in the TACE group; and 88.5, 64.6 and 44.3% respectively in the combination group. There was a significant difference in survival between the combination group and the TACE group ( P  = 0.028).
Conclusion:  RFA combined with TACE was more effective in treating recurrent HCC after hepatectomy compared to single RFA or TACE treatment. This combination therapy can thus be a valuable choice of treatment for recurrent HCC.     

Major complications of ultrasound-guided percutaneous radiofrequency ablations for liver malignancies: Single center experience

Background and Aim:  Despite radiofrequency ablation (RFA) for malignant liver nodular lesions having promising therapeutic effects, the trade-off between the risks and benefits must be acceptable. This study analyzed the major complications of ultrasound (US)-guided percutaneous RFA procedures encountered at a single center, by a single physician.
Methods:  A total of 104 patients (total 183 tumors) underwent 172 US-guided percutaneous RFA sessions between May 2003 and March 2006. The definition of major complications was according to the standardized Society of Interventional Radiology grading system (classification C-E).
Results:  Eighty-six patients had hepatocellular carcinoma (HCC) and 18 patients had hepatic metastatic tumors. Nine major complications occurred from 172 RFA sessions (9/172, incidence of 5.2% per session); namely, two cases of transient liver function impairment, two cases of infection (liver abscess and septicemia), two cases of tumor seeding along the ablated track, one case of colon perforation, one case of acalculous cholecystitis and, lastly, a case of hemocholecyst. We further analyzed the possible risk factors precipitating these complications, and found that only tumor size (Pearson's correlation coefficient, 0.324; P  < 0.05) and baseline liver function reserve (compensated 0%, 0/148 vs decompensated 8.3%, 2/24; P  = 0.019) were significant factors for the complication of transient liver function impairment.
Conclusion:  Radiofrequency ablation for liver malignancy is a safe procedure with acceptable incidence of complications. Decompensated baseline liver function reserve and large tumor size are precipitating factors for transient liver function impairment after RFA and warrant a close follow up.     

Assessment of radiofrequency ablation margin by MRI-MRI image fusion in hepatocellular carcinoma

AIM:To investigate the feasibility and clinical value of magnetic resonance imaging(MRI)-MRI image fusion in assessing the ablative margin(AM) for hepatocellular carcinoma(HCC).METHODS:A newly developed ultrasound workstation for MRI-MRI image fusion was used to evaluate the AM of 62 tumors in 52 HCC patients after radiofrequency ablation(RFA).The lesions were divided into two groups:group A,in which the tumor was completely ablated and 5 mm AM was achieved(n = 32);and group B,in which the tumor was completely ablated but 5 mm AM was not achieved(n = 29).To detect local tumor progression(LTP),all patients were followed every two months by contrast-enhanced ultrasound,contrast-enhanced MRI or computed tomography(CT) in the first year after RFA.Then,the follow-up interval was prolonged to every three months after the first year.RESULTS:Of the 62 tumors,MRI-MRI image fusion was successful in 61(98.4%);the remaining case had significant deformation of the liver and massive ascites after RFA.The time required for creating image fusion and AM evaluation was 15.5 ± 5.5 min(range:8-22 min) and 9.6 ± 3.2 min(range:6-14 min),respectively.The follow-up period ranged from 1-23 mo(14.2 ± 5.4 mo).In group A,no LTP was detected in 32 lesions,whereas in group B,LTP was detected in 4 of 29 tumors,which occurred at 2,7,9,and 15 mo after RFA.The frequency of LTP in group B(13.8%;4/29) was significantly higher than that in group A(0/32,P = 0.046).All of the LTPs occurred in the area in which the 5 mm AM was not achieved.CONCLUSION:The MRI-MRI image fusion using an ultrasound workstation is feasible and useful for evaluating the AM after RFA for HCC.     

Usefulness of the hyperechoic rim for assessing the therapeutic efficacy of radiofrequency ablation in hepatocellular carcinoma patients

Aim:  During radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), a hyperechoic rim develops around the HCC nodules. The usefulness of the hyperechoic rim to guide treatment was assessed.
Methods:  RFA was first performed in pig livers to determine the significance of the hyperechoic rim. Fifty-five patients with 75 HCC nodules had received RFA for the treatment of HCC. For those patients, we evaluated whether conventional ultrasonography (US) could be used instead of contrast-enhanced computed tomography (CECT) and contrast-enhanced ultrasonography (CEUS) using virtual imaging. Finally, 31 patients with 45 HCC nodules received RFA, and the degree of ablation was assessed based on the hyperechoic rim. Repeated RFA was done when ablation appeared incomplete.
Results:  In the pig livers, the hyperechoic rim was found to be related to the presence of dead cells. The preliminary study showed that US could be used instead of CECT and CEUS to evaluate the degree of ablation caused by RFA. Because hepatic vessels in the back side of the hyperechoic rim were not clear by the artifact, we used the distance from the surface of the liver to the hyperechoic rim for evaluation. By analyzing the extent of the hyperechoic rim, it was noted that incomplete ablation was achieved in 17 of 31 patients (21 of 45 HCC nodules). These patients were re-treated with RFA within 5–15 min of the first RFA.
Conclusion:  This study shows that the hyperechoic rim is related to the presence of dead and necrotic tissues. Thus, assessment of the hyperechoic rim's characteristics allows one to evaluate the efficacy of RFA.     

Heat Sink Effect on Tumor Ablation Characteristics as Observed in Monopolar Radiofrequency,Bipolar Radiofrequency,and Microwave,Using Ex Vivo Calf Liver Model

Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink.     

Radiofrequency ablation of pulmonary tumors and normal lung tissue in swine and rabbits

OBJECTIVE: The purpose of the present study was to examine the following during radiofrequency ablation (RFA): (1) the risk of hemorrhage from intrapulmonary large vessels; (2) the risk of incomplete ablation of pulmonary tumors; and (3) the late effect on lung tissue. MATERIALS AND METHODS: A 17-gauge, cool-tip-type radiofrequency electrode was used. The damage to the vessels and bronchi was examined by the injection of a colored silicone rubber, a liquid compound that hardens after injection. To examine the risk of hemorrhage from intrapulmonary large vessels, RFA was conducted at eight sites near the central pulmonary vessels in two swine. To examine the risk of an incomplete ablation for pulmonary tumors, 10 pulmonary nodules were made from a gelatin mixture in another two swine and were treated by RFA. To examine the late effect on lung tissue, RFA was conducted on the peripheral lung in 10 rabbits, and then the ablated regions were examined on days 1, 7, 14, 21, and 28 after RFA. RESULTS: The use of colored silicone rubber enabled us to examine the intrapulmonary vessels and bronchi for opening and leakage. RFA did not damage the large intrapulmonary vessels, even when they were located within the ablated regions. Lung tissue surrounding the gelatin nodules was hardly ablated over its entire circumference. Six of 10 gelatin nodules (60%) showed nonablated areas on the peripheral edges of the nodules. From 21 days after RFA, the ablated rabbit lung formed noninfectious cavities by communicating with the surrounding bronchi. CONCLUSION: It was improbable for hemorrhage to occur even when RFA was conducted near the large intrapulmonary large vessels. Because an incomplete ablation that left tumor cells at the site of ablation could occur during surgery due to the difficulty of ablating the entire tumor circumference, CT scan-guided RFA would be preferable to a surgical approach for making a safe margin. Cavity formation can occur beginning 21 days after RFA, which should be carefully followed up in a clinical setting to identify infection, especially in immunocompromised patients.     

Efficacy of a single 24-hour pre-anesthetic dose of proton pump inhibitors

Background and Aim:  The H₂ receptor antagonist roxatidine is routinely used as an oral pre-anesthetic medication in surgical patients at night and 2 h before surgery. In the present study, we have compared the effects of roxatidine, rabeprazole and lansoprazole given singly at night as an alternative to the standard double roxatidine medication.
Methods:  120 adult patients undergoing urological surgery were randomly assigned to three groups: roxatidine, rabeprazole and lansoprazole ( n  = 40 each). Following induction of anesthesia, gastric fluid was obtained by aspiration using a syringe to measure pH and volume of gastric contents.
Results:  Gastric volume (14.1 ± 1.9 mL) in the lansoprazole group was significantly larger than that in roxatidine (8.6 ± 1.7 mL) and rabeprazole (7.5 ± 1.1 mL) groups ( P  < 0.05). Gastric pH in lansoprazole group (4.10 ± 0.38) was also significantly lower than that in the roxatidine group (5.41 ± 0.31, P  < 0.05). The numbers of patients with critical factors for acid aspiration pneumonia (gastric pH < 2.5 or volume > 25 mL) in the lansoprazole group was significantly higher than in the roxatidine group ( P  < 0.05). Gastric pH and volume in all groups were constant even in the afternoon.
Conclusion:  Single rabeprazole (but not lansoperazole) medication may be a suitable alternative to standard roxatidine for prophylaxis of acid aspiration pneumonia.     

Kinetics of indocyanine green removal from blood can be used to predict the size of the area removed by radiofrequency ablation of hepatic nodules

BACKGROUND AND AIM: The size of radiofrequency ablation (RFA) in the liver can be negatively influenced by the surrounding blood flow. The indocyanine green (ICG) test can be used to evaluate the effective blood flow in the liver, and distance from the hilus can affect local blood flow. The aim of this study was to assess whether the ICG test or distance from the hilus could be used to predict the size of the ablated area in liver by RFA treatment of hepatocellular carcinoma (HCC) nodules. METHODS: The RFA measurements of 44 HCC nodules in 39 patients were retrospectively studied. Cases were included if they met the following criteria: (i) no catheter treatment before RFA; (ii) no movement of the RFA device; (iii) strict ablation time; and (iv) only one ablation. In all patients, ICG-R15 testing was done immediately before RFA and the initial therapeutic efficacy was evaluated by dynamic computed tomography scanning 2-5 days after RFA. The correlation between the maximum size of the RFA area and the ICG test results or the distance of the target area from the hilus (site of first portal vein divergence) were analyzed statistically. RESULTS: The ICG-R15 result was significantly correlated with the maximum diameter of the ablated area both in 2 cm-electrode tip length (R2 = 0.35, P = 0.0012), and in 3 cm-tip length (R2 = 0.26, P = 0.0377). Multiple-regression analysis showed that the electrode tip length (P = 0.0010) and ICG-R15 (P = 0.0046) were independent factors that could predict the maximum diameter of the RFA area. CONCLUSION: The results of ICG testing can be used to predict the size of the area that will be ablated at a target liver site before RFA treatment.     

Feasibility of functional magnetic resonance lung imaging in Australia with long distance transport of hyperpolarized helium from Germany

Background and objective:   MRI of the lung using hyperpolarized helium as an inhaled contrast agent has important research applications and clinical potential. Owing to the limited availability of hyperpolarized helium, this type of imaging has not been performed in the human lung outside of North America or Europe. The objective of this study was to test the feasibility of imaging human lungs in Australia using hyperpolarized helium gas imported from Germany.
Methods:   A Bruker 2-Tesla whole-body magnetic resonance scanner located in Brisbane, Australia was adapted with a helium-3 radiofrequency transceiver coil. Helium-3 was hyperpolarized to 72% in Mainz, Germany and airfreighted to Brisbane. The time taken for the journey was 32 h and scanning was performed 36–40 h after departure from Mainz, with an estimated polarization level of 44%. Procedures were developed to transfer 300 mL of the hyperpolarized helium to Tedlar bags filled with 700 mL of nitrogen. Healthy volunteers inhaled the 1 L helium/nitrogen mixture from FRC, and imaging was performed with a 10 s breathhold.
Results:   Imaging showed very detailed and even ventilation of all regions of the lung with a good signal-to-noise ratio. No adverse effects of inhaling the gas mixture were noted.
Conclusions:   This report of MRI of the human lung using hyperpolarized helium demonstrates the feasibility of long distance gas transport from Germany to Australia. This will help to facilitate research and clinical application of this innovative functional lung imaging technique.     

Intraductal chilled saline perfusion to prevent bile duct injury during percutaneous radiofrequency ablation for hepatocellular carcinoma

Background and Aim:  Radiofrequency ablation (RFA) is a promising, minimally invasive treatment for hepatocellular carcinoma (HCC). However, thermal injury sometimes occurs in the bile duct, potentially leading to a critical situation. The aim of the present study was to investigate whether bile duct injury is reduced by an intraductal chilled saline perfusion (ICSP) through a nasobiliary tube during RFA for HCC.
Patients and Methods:  The baseline incidence of bile duct injury at Gifu Municipal Hospital was 3.1% (13 patients) in 424 patients with HCC treated by percutaneous RFA. In all patients, the tumor was within 5 mm of the central bile duct on CT images. The incidence of bile duct injury was 46% among the 28 selected patients whose tumor was close to the central bile duct. To prevent complications in such high-risk patients, we placed a nasobiliary tube endoscopically before RFA, and performed ICSP during RFA. Forty consecutive patients with tumors close to the central bile duct were enrolled in this study.
Results:  Of the 40 enrolled patients, only one had biliary injury, whereas the remaining 39 patients were able to avoid it. The incidence of biliary injury was significantly reduced in the ICSP group (1/40, 2.5%) compared to that in the control group (13/28, 46%) ( P  < 0.0001). Moreover, the liver function 6 months after RFA was also better preserved in the ICSP group according to Child–Pugh grading, thus resulting in a better clinical outcome.
Conclusions:  ICSP through a nasobiliary tube is a potential intervention method to prevent biliary injury by percutaneous RFA.     

Combined hepatectomy and radiofrequency ablation versus TACE in improving survival of patients with unresectable BCLC stage B HCC

BACKGROUND: Combined hepatectomy and radiofrequency ablation(RFA) provides an additional treatment for patients with Barcelona Clinic Liver Cancer(BCLC) stage B hepatocellular carcinoma(HCC) who are conventionally deemed unresectable. This study aimed to analyze the outcome of this combination therapy by comparing it with transarterial chemoembolization(TACE). METHODS: We retrospectively reviewed 51 patients with unresectable BCLC stage B HCC who had received the combination therapy. We compared the survival of these patients with that of 102 patients in the TACE group(control). Prognostic factors associated with worse survival in the combination group were analyzed.RESULTS: No differences in tumor status and liver function were observed between the TACE group and combination group. The median survival time for the combination group and TACE group was 38(6-54) and 17(3-48) months, respectively(P0.001). The combination group required longer hospitalization than the TACE group [8(5-14) days vs 4(2-9) days,P0.001]. More than two ablations decreased the survival rate in the combination group. CONCLUSIONS: Combined hepatectomy and RFA yielded a better long-term outcome than TACE in patients with unresectable BCLC stage B HCC. Patients with a limited ablated size(≤2 cm), a limited number of ablations(≤2), and adequate surgical margin should be considered candidates for combination therapy.     

Radiofrequency ablation of hepatocellular carcinoma: The feasibility of magnetic resonance imaging with gadolinium ethoxybenzyl diethylene triamine pentaacetic acid for evaluating the ablative margin

Aim: The aim of this study was to evaluate the feasibility of gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd‐EOB‐DTPA) in magnetic resonance imaging (MRI) to assess the ablative margin of radiofrequency (RF) ablation to hepatocellular carcinoma (HCC). Methods: RF ablation was performed in the livers of six pigs after the i.v. administration of Gd‐EOB‐DTPA 20 min before ablation. Three pigs were killed 2 h after administration (group A), and the other pigs were killed 7 days after ablation (group B). Thereafter, correlation between pathological findings and MRI was investigated. Moreover, the Gd concentrations were examined in ablated and non‐ablated regions. An initial clinical evaluation was conducted for 28 HCC nodules. Percutaneous RF ablation was performed 20 min after administration, and T₁‐weighted images were taken 2, 24 and 72 h post‐treatment. Results: On T₁‐weighted images of the porcine liver, the RF ablated lesions showed hyperintense regions with hypointense rims, which histopathologically corresponded to sinusoidal congestion. The Gd concentrations in ablated regions in group A were significantly higher than those in non‐ablated regions, while the concentrations in both regions in group B fell to nearly undetectable levels. In 27 of the 28 HCC nodules, the treated area consisted of a hypointense region, indicative of the tumor, and a surrounding hyperintense rim 2 h after ablation. Subsequently, a thin hypointense region was observed in the outermost layer 24 and 72 h after ablation. Conclusion: Administration of Gd‐EOB‐DTPA in conjunction with RF ablation of HCC may be feasible for the assessment of an accurate ablative margin.     

Assessment of gastric motor function by cine magnetic resonance imaging

Background and Aim:  The aim of the present study was to evaluate gastric motor function by magnetic resonance imaging (MRI) and investigate whether this examination is a useful tool for therapeutic efficacy or postoperative gastric motor function.
Methods:  Twenty-five healthy volunteers and 10 gastric cancer patients with pylorus-preserving gastrectomy (PPG) underwent cine-MRI. Gastric volume was determined by 3D-volumetry. Gastric motility was quantified by calculating the gastric motility index (GMI).
Results:  The image acquisition and analysis were successfully carried out for all subjects. In healthy volunteers, mean frequency, amplitude, velocity of gastric peristaltic waves and GMI 30 min after the intake of jelly were 3/min, 8.8 mm, 2.2 mm/s and 19.6 mm²/s, respectively. Mean amplitude (8.8 vs 10.4 mm, P  = 0.027), velocity (2.2 vs 2.6 mm/s, P  < 0.001) of peristaltic waves, and GMI (19.6 vs 26.7 mm²/s, P  < 0.001) significantly increased at 30 min after giving mosapride citrate (MS). Mean gastric volume after MS administration was significantly decreased; 0 min (317.3 vs 272.9 mL, P  = 0.021), 45 min (263.4 vs 206.4 mL, P  = 0.004) and 60 min (228.7 vs 165 mL, P  = 0.001). PPG patients with postprandial symptoms were observed having antiperistalsis-like contraction waves and reflux of gastric contents from the pyloric region into the upper part of the stomach. Mean gastric volume in PPG patients with postprandial symptoms at 30 min after intake of jelly tended to be greater than in those without such symptoms.
Conclusions:  The present study demonstrates that cine-MRI is a sensitive and non-invasive imaging technique for simultaneously measuring gastric motility and emptying.     

Radiofrequency Catheter Ablation of Idiopathic Left Ventricular Tachycardia Originating in Both Left Posterior and Anterior Fascicles

A 45-year-old woman underwent radiofrequency ablation (RFA) for symptomatic idiopathic left ventricular tachycardia (ILVT). The clinical arrhythmias had two different patterns, a wide QRS tachycardia with right bundle branch block (RBBB) and left axis deviation (LAD) and another with RBBB and right axis deviation (RAD). The electrophysiology study localized the origin of tachycardias to the midinferior and superior ventricular septum, respectively. RFA terminated successfully ILVT with RBBB and LAD morphology, but another pattern could not be ablated. Noncontact mapping revealed the earliest site of activation at the superior septum. RFA at this site terminated successfully ILVT with RBBB and RAD.     

Oxidant stress mediates inflammation and apoptosis in ventilator-induced lung injury

Background and objective:   Ventilator-induced lung injury (VILI) leads to airway epithelial cell apoptosis and lung inflammation. High tidal volume ventilation in vivo has been shown to induce MIP-2 production, lung neutrophil sequestration and apoptotic airway cell death. This study aimed to determine the effect of N-acetylcysteine (NAC), a scavenger of oxygen radicals, on lung inflammation and apoptosis in an in vivo model of VILI.
Methods:   Sprague–Dawley rats ( n  = 5 per group) were ventilated at low tidal volume (V_T 7 mL/kg) or high tidal volume (V_T 20 mL/kg) with or without administration of 140 mg/kg of intravenous NAC. Animals were ventilated for 30 min, 1 or 2 h, then allowed to recover for 2 h, at which time neutrophil infiltration, MIP-2, TNF-α and IL-6 in BAL fluid, as well as the percentage of apoptotic airway epithelial cells, were measured.
Results:   Ventilation at V_T 20 mL/kg increased oxidant release, as measured by serum isoprostane, and decreased lung glutathione, the major antioxidant in the lung. NAC treatment during ventilation at V_T 20 mL/kg prevented the decrease in lung glutathione and significantly lowered serum isoprostane levels, neutrophil infiltration, cytokines in the BAL and apoptosis in the airways as compared with animals ventilated at V_T 20 mL/kg without NAC ( P  < 0.05).
Conclusions:   These data point to an early role of oxidant-induced inflammation and apoptosis in VILI.