Katsuyoshi Tamaki

Complications of radiofrequency ablation for hepatocellular carcinoma in a multicenter study: An analysis of 16 346 treated nodules in 13 283 patients

Aim:  We surveyed multiple centers to identify types and frequency of complications and mortality rate associated with radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).

Experimental and clinical radiofrequency ablation: Proposal for standardized description of coagulation size and geometry

BackgroundRadiofrequency (RF) ablation is used to obtain local control of unresectable tumors in liver, kidney, prostate, and other organs. Accurate data on expected size and geometry of coagulation zones are essential for physicians to prevent collateral damage and local tumor recurrence. The aim of this study was to develop a standardized terminology to describe the size and geometry of these zones for experimental and clinical RF.MethodsIn a first step, the essential geometric parameters to accurately describe the coagulation zones and the spatial relationship between the coagulation zones and the electrodes were defined. In a second step, standard terms were assigned to each parameter.ResultsThe proposed terms for single-electrode RF ablation include axial diameter, front margin, coagulation center, maximal and minimal radius, maximal and minimal transverse diameter, ellipticity index, and regularity index. In addition a subjective description of the general shape and regularity is recommended.ConclusionsAdoption of the proposed standardized description method may help to fill in the many gaps in our current knowledge of the size and geometry of RF coagulation zones.

Inhibitory effect of a soluble transforming growth factor β type II receptor on the activation of rat hepatic stellate cells in primary culture

BACKGROUND/AIMS Oxidative stress, including the generation of reactive oxygen species (ROS) that acts as a signaling mediator for transforming growth factor (TGF)-beta, plays a key role in hepatic fibrosis. Hepatic stellate cells (HSCs) produce and respond to TGF-beta in an autocrine manner with increased collagen expression. It has previously been reported that the adenovirus-mediated overexpression of a soluble receptor against the extracellular domain of the TGF-beta type II receptor prevents hepatofibrogenesis in vivo, although its inhibitory role and mechanism in HSC activation remains to be elucidated. METHODS In this study, we report on an examination of the actual role of TGF-beta inhibition on oxidative stress and the activation of cultured rat HSCs, using the adenovirus-mediated soluble TGF-beta type II receptor. RESULTS This soluble receptor secreted from the adenovirus-infected cells binds to TGF-beta. Infection of HSCs with this adenovirus attenuated intracellular levels of TGF-beta1 mRNA and protein, NADH oxidative activity, ROS generation and lipid peroxidation, and prevented HSC activation. CONCLUSIONS These findings suggest that this adenovirus-mediated soluble TGF-beta receptor may lead to an interruption of the TGF-beta autocrine loop in activated HSC, in part, by inhibiting oxidative stress.

Influence of large intrahepatic blood vessels on the gross and histological characteristics of lesions produced by radiofrequency ablation in a pig liver model

Abstract: Aims: To determine whether the presence of large intrahepatic blood vessels (≥3 mm) affect radiofrequency (RF)‐induced coagulation necrosis, the gross and histological characteristics of RF‐ablated areas proximal to or around vessels were examined in normal pig livers.

Reducing Effect of Feeding Powdered Nacre of Pinctada maxima on the Visceral Fat of Rats

An abdominal fat accumulation complicated by high blood triglycerides is regarded as a risk factor of metabolic syndrome. Feeding powdered nacre, mother of pearl, from Pinctada maxima, resulted in reduced body weight, visceral fat amount, and blood triglyceride level without influencing the food intake, body length, or amount of muscular tissue, suggesting that nacre powder specifically could decrease visceral fat.

Novel des-γ-carboxy prothrombin in serum for the diagnosis of hepatocellular carcinoma.

Serum des‐γ‐carboxy prothrombin (DCP) levels using a newly developed electrochemiluminescence immunoassay (ECLIA, novel DCP [NX‐DCP]) were measured, and the utility of NX‐DCP and DCP/NX‐DCP ratio for the diagnosis of hepatocellular carcinoma (HCC) was investigated. Antigenic differences in DCP between HCC and non‐HCC patients were elucidated.

Simeprevir with peginterferon and ribavirin induced interstitial pneumonitis: First case report

The effectiveness of hepatitis C treatment has improved with the development of interferon (IFN), and it has drastically improved with the development of peg-interferon-α (PEG-IFN) in combination with ribavirin (RBV) and, more recently, with the addition of a protease inhibitor. Simeprevir, which is a second-generation protease inhibitor, has shown clinically favorable safety and tolerability profiles. Simeprevir received its first global approval in Japan in September 2013 for the treatment of genotype 1 chronic hepatitis C in combination with PEG-IFN and RBV. One serious adverse event associated with IFN therapy is interstitial pneumonitis, which can be fatal. We experienced a patient with interstitial pneumonitis that was induced by simeprevir with PEG-IFN and RBV therapy for chronic hepatitis C in the early stages of therapy (8 wk after initiating therapy). This is the first case report of interstitial pneumonitis with simeprevir with PEG-IFN and RBV in the world. In addition, it is very interesting that the onset of interstitial pneumonitis was earlier than that in conventional PEG-IFN and RBV therapy. This finding suggests that simeprevir augments the adverse event. We present this case report in light of relevant literature on interstitial pneumonitis with conventional PEG-IFN and RBV therapy.

Radiofrequency Ablation Using a Balloon Catheter for Hepatocellular Carcinoma Adjacent to the Gastrointestinal Tract: Experimental and Clinical Study

Purpose: Radiofrequency ablation (RFA) is a safe and effective technique for hepatocellular carcinoma and it has minimal morbidity and mortality. One of the most important major complications of RFA is perforation of the gastrointestinal tract, which occurs when the tumor is adjacent to the digestive tract. In particular, the risk is much higher in patients with lesions located within 1 cm from the liver surface in proximity to the digestive tract. In such cases, an artificial ascites technique has been employed. However, the separation of adjacent digestive organ from the liver is insufficient in this method. Therefore, in this study, to overcome this problem, we devised a novel RFA technique using a double-balloon catheter. In the first step, an animal experiment was performed to evaluate the safety and feasibility of the balloon RFA method. In the second step, the human pilot trial was carried out to evaluate the safety, feasibility and effectiveness of this method. Materials and Methods: We produced an 8 Fr silicone catheter equipped with 2 balloons of 2.5 cm diameter. In experiments using pigs, we first inserted this balloon catheter percutaneously into the peritoneal space between the liver and gastrointestinal tracts, filled it with cooled water, and performed RFA for in normal liver 1 cm from the liver surface. Then, heat damage to the excised liver and gastrointestinal tract was evaluated macroscopically andmicroscopically. In a human pilot study, balloon catheter RFA was performed in 4 patients with HCC (1.5 ± 0.7 cm) abutting the gastrointestinal tract. Results: In pigs, we performed each 6 RFA sessions with or without balloon catheter. It was technically easy to place the balloon catheter between liver and gastrointestinal tracts to separate them. Heat damage reached the liver surface in all lesions. In the groupwith balloon catheter, no heat damage of the gastrointestinal tracts was observed (0%, 0/6). In contrast, in the group without balloon catheter, heat damage was observed in 5/6 (83.3%): stomach (2/6), small intestine (2/6), and omentum (1/6). The coolant temperature in the balloon was significantly increased after RFA, suggesting that the heat generated by RFA was absorbed by the coolant. In the human pilot study, balloon catheter RFA was easily performed in all patients without associated complications. CT confirmed complete ablation with an appreciable safety margin in all patients, without recurrence for 20.3 ± 4.5 months. Conclusions: RFA with our balloon catheter is safe and effective for the treatment of HCC abutting the gastrointestinal tract, suggesting an expanded indication of these lesions for RFA.