Yasukazu Kako

Thermal ablation and immunomodulation: From preclinical experiments to clinical trials

Accumulating evidence has shown that thermal ablation can induce spontaneous distant tumor regression, which is also known as abscopal effect. Abscopal effect might depend upon the activation of antitumor immune response. However, such responses induced by thermal ablation had been thought to be usually weak and that they rarely induce distant tumor regression. Recently, results of several preclinical and clinical studies have suggested that thermal ablation can induce therapeutically effective systemic antitumor immune response if appropriate immunomodulators are combined. To elucidate the mechanisms of these promising strategies, effects of thermal ablation on the immune system are overviewed. Furthermore, recent promising preclinical and clinical studies examining enhancement of systemic antitumor immune response by combining thermal ablation and immunomodulation are summarized.

Changes in liver stiffness on real-time tissue elastography before and after occlusion of spontaneous portosystemic shunts

PURPOSE This study was conducted to evaluate changes in liver stiffness, volume, and function before and after occlusion of spontaneous portosystemic shunt. MATERIALS & METHODS Twenty-four patients (13 men and 11 women) with a mean age of 68.2 years±10.1 (SD) (age range, 49-82 years) underwent percutaneous occlusion of spontaneous portosystemic shunt because of gastric varices (n=17) or hepatic encephalopathy (n=7) from March 2011 to June 2013. The liver fibrosis index indicating liver stiffness was calculated by using ultrasound elastography before and after shunt occlusion. Liver volume and liver profile were also evaluated. RESULTS Spontaneous portosystemic shunt occlusion was uneventfully performed in all patients. The mean liver fibrosis index was significantly decreased from 2.7±1.0 before shunt occlusion to 2.0±0.9 (P<0.001) at 1 month, 2.2±1.0 at 3 months (P=0.004), and 1.6±0.7 at 6 months (P=0.001) afterwards. A significant increase in the liver volume was observed from 1035.3±340.1mL before shunt occlusion to 1116.8±298.4mL (P=0.006) at 1 month and 1174.2±354.1mL (P<0.001) at 3 months afterwards. Significant improvement in the Child-Pugh score was also found at 1 month (6.2±1.4, P<0.001), 3 months (6.5±1.1, P=0.022), and 6 months (6.0±0.9, P=0.004) after shunt occlusion as compared with that (7.2±1.9) before. CONCLUSION The liver stiffness decreases along with an increase in liver volume and improvement in liver function after spontaneous portosystemic shunt occlusion.

Balloon-occluded retrograde transvenous obliteration of varices: focusing on the portal hemodynamics and the recent techniques

PurposeTo evaluate the recent topics of Ballloon-occluded retrograde trasnvenous obliteration(B-RTO).MethodWe overviewed the recent scientific papers regarding B-RTO.ResultB-RTO is a treatment method for occluding varices retrogradely using a sclerosing agent under balloon occlusion of a major draining vein. It has been recognized as an effective treatment method for gastric varices. Hepatic function reserve is improved and liver volume is increased after B-RTO. In recent years, various technical options, such as plug-assisted retrograde transvenous obliteration, coil-assisted retrograde transvenous obliteration, or foam B-RTO, have also been reported. In performing B-RTO, portal hemodynamics must be thoroughly examined radiologically. Judging the classification of the grade of collateral venous hemodynamics is important to select the appropriate embolization technique of B-RTO and to successfully occlude varices. Finally, the word “portosystemic shunt syndrome” has been proposed and the condition should be considered while selecting a treatment for gastric varices.ConclusionB-RTO is effective for gastrointestinal varices and portosystemic shunts.

Hemorrhagic shock due to ruptured left and right gastric artery aneurysm

We report a case of hemorrhagic shock due to a ruptured gastric artery aneurysm successfully treated with transarterial embolization. A 72‐year‐old woman with cholangitis presented with hemoperitoneum following a ruptured aneurysm of the gastric artery.

Transportal Embolization of Intrahepatic Arterioportal Fistulae Refractory to Arterial Embolization

avoided as primary embolization agents because of the presence of multiple feeding vessels and risk of nontarget embolization. Angiography performed after embolization demonstrated no flow into the aneurysm sac (Fig 2b). The pelvic drainage catheter was removed after the output decreased to o 5 mL/d. The patient was discharged from the hospital 3 days after the procedure. A follow-up CT scan performed at 9 months demonstrated complete occlusion of the aneurysm and no signs of recanalization with a patent intrahepatic and extrahepatic portal vein (Fig 3). PVAs are the most common visceral venous aneurysm, although still extremely rare with a reported prevalence of up to 0.43% (1). Extrahepatic PVAs (defined as 4 2 cm) are more common than intrahepatic PVAs (defined as 4 9 mm) (1). PVAs can be congenital or acquired. Common etiologies of PVA include chronic liver disease (with or without portal hypertension), pancreatitis, trauma, and malignant invasion. Most patients are asymptomatic or present with unrelated abdominal pain, and the PVA is usually diagnosed incidentally (1–3). In our case, although the diagnosis was incidental, the PVA may have been related to hematogenous spread of infection from a diverticular abscess eroding into the mesenteric veins. Rupture of a rapidly growing PVA is rare. Most PVAs require no treatment and are monitored with imaging (commonly vascular ultrasound). Surgical treatment of a PVA is recommended if the patient is symptomatic or if the aneurysm enlarges (2). Surgical interventions include aneurysmorrhaphy for saccular aneurysms and aneurysmectomy for fusiform aneurysms (3). Portocaval or mesocaval shunts may be placed to prevent aneurysm