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Dive into the research topics where Akira Ikoma is active.

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Featured researches published by Akira Ikoma.


Japanese Journal of Radiology | 2010

Prospective comparison of transcatheter arterial chemoembolization with Lipiodol-epirubicin and Lipiodol-cisplatin for treatment of recurrent hepatocellular carcinoma

Shinya Sahara; Nobuyuki Kawai; Morio Sato; Hiroki Minamiguchi; Motoki Nakai; Isao Takasaka; Kouhei Nakata; Akira Ikoma; Naohisa Sawa; Tetsuo Sonomura; Shintaro Shirai

PurposeThe aim of this study was to compare the safety and short-term efficacy of transcatheter arterial chemoembolization (TACE) using cisplatin-Lipiodol suspension (CP/Lp) with that using epirubicin-Lipiodol emulsion (EP/Lp) in patients with recurrent hepatocellular carcinoma (HCC).Materials and methodsA total of 28 HCC patients were enrolled prospectively and assigned to the CP/Lp group or EP/Lp group. Adverse effects related to TACE were graded; and the treatment effect (TE) on HCC nodules at 3 months and overall tumor response at 6 months were assessed as the endpoint.ResultsNo significant difference was observed between the groups regarding the frequency of adverse effects of grade 3 or less. The TE rates for 100% necrosis plus >50% necrosis in 62 HCC nodules in the CP/Lp group and 75 HCC nodules in the EP/Lp group were 72.6% and 66.7%, respectively (P = 0.894). Overall tumor response revealed that six patients (50.0%) in the CP/Lp group and six patients (37.5%) in the EP/Lp group had a partial response plus a complete response, with no significant difference (P = 0.615). TACE-free control curves for both groups revealed no significant difference (P = 0.513).ConclusionNo significant difference was found with regard to adverse effects, the treatment effect on HCC nodules, or overall tumor response between the CP/Lp and EP/Lp groups.


World Journal of Gastroenterology | 2012

Preoperative microcoil embolization of the common hepatic artery for pancreatic body cancer

Isao Takasaka; Nobuyuki Kawai; Morio Sato; Hirohiko Tanihata; Tetsuo Sonomura; Hiroki Minamiguchi; Motoki Nakai; Akira Ikoma; Kouhei Nakata; Hiroki Sanda

AIM To evaluate safety and feasibility of microcoil embolization of the common hepatic artery under proper or distal balloon inflation in preoperative preparation for en bloc celiac axis resection for pancreatic body cancer. METHODS Fifteen patients (11 males, 4 females; median age, 67 years) with pancreatic body cancer involving the nerve plexus surrounding the celiac artery underwent microcoil embolization. To alter the total hepatic blood flow from superior mesenteric artery (SMA), microcoil embolization of the common hepatic artery (CHA) was conducted in 2 cases under balloon inflation at the proximal end of the CHA and in 13 cases under distal microballoon inflation at the distal end of the CHA. RESULTS Of the first two cases of microcoil embolization with proximal balloon inflation, the first was successful, but there was microcoil migration to the proper hepatic artery in the second. The migrated microcoil was withdrawn to the CHA by an inflated microballoon catheter. Microcoil embolization was successful in the other 13 cases with distal microballoon inflation, with no microcoil migration. Compact microcoil embolization under distal microballoon inflation created sufficient resistance against the vascular wall to prevent migration. Distal balloon inflation achieved the requisite 1 cm patency at the CHA end for vascular clamping. All patients underwent en bloc celiac axis resection without arterial reconstruction or liver ischemia. CONCLUSION To impede microcoil migration to the proper hepatic artery during CHA microcoil embolization, distal microballoon inflation is preferable to proximal balloon inflation.


Korean Journal of Radiology | 2014

N-butyl cyanoacrylate embolization with blood flow control of an arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma.

Tetsuo Sonomura; Nobuyuki Kawai; Kazushi Kishi; Akira Ikoma; Hiroki Sanda; Kouhei Nakata; Hiroki Minamiguchi; Motoki Nakai; Seiki Hosokawa; Hideyuki Tamai; Morio Sato

We present a case of a patient with rapid deterioration of esophageal varices caused by portal hypertension accompanied by a large arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma. We used n-butyl cyanoacrylate (NBCA) as an embolic material to achieve pinpoint embolization of the shunt, because the microcatheter tip was 2 cm away from the shunt site. Under hepatic arterial flow control using a balloon catheter, the arterioportal shunt was successfully embolized with NBCA, which caused an improvement in the esophageal varices.


Journal of Vascular and Interventional Radiology | 2012

Basic Study of a Mixture of N-butyl Cyanoacrylate, Ethanol, and Lipiodol as a New Embolic Material

Nobuyuki Kawai; Morio Sato; Hiroki Minamiguchi; Akira Ikoma; Hiroki Sanda; Kouhei Nakata; Fumihiro Tanaka; Motoki Nakai; Tetsuo Sonomura

PURPOSE To clarify the configuration change of N-butyl cyanoacrylate (NBCA) polymerization with increasing proportion of ethanol, the properties of a mixture of NBCA with lipiodol plus ethanol (NLE), and the feasibility of use of NLE for aneurysm packing in a swine model. MATERIALS AND METHODS The polymerization configuration of NLE was explored using ratios of 1-4 parts NBCA and 1-3 parts ethanol per 1 part of lipiodol; a 1:1 ratio of NBCA to lipiodol (NLE110) was used as a control. The distance that NLE migrated into saline flowing in a tube was measured. A carotid artery aneurysm was created in each of 18 swine. Aneurysmal packing with three configurations--NLE110, NLE at a ratio of 1:1:2 (NLE112), and NLE at a ratio of 1:1:3 (NLE113)--was attempted in six swine for each configuration. RESULTS Regardless of NBCA composition, medium-sized droplets, a single large droplet, and a noodle-shaped extrusion were observed in NLE with lipiodol versus ethanol ratios of 1:1, 1:2, and 1:3. NLE110 migrated as viscous fluid to 190 cm from the injection site, whereas NLE112 migrated for 81 cm ± 11 and NLE113 migrated for 74 cm ± 9. Instant outflow of NLE110 from the six aneurysms caused occlusion of the parent artery, with adhesion to the microcatheter. Packing was achieved with minimal adhesion for all six of the aneurysms packed with NLE112 or with NLE113. CONCLUSIONS With high ratios of ethanol, the NLE polymerization configuration acquired solid-like properties with potent occlusive ability and negligible adhesion to the microcatheter, suggesting its feasibility for packing of aneurysms.


Journal of Computer Assisted Tomography | 2012

Differentiation of pancreatic serous cystadenoma from endocrine tumor and intraductal papillary mucinous neoplasm based on washout pattern on multiphase CT.

Shinya Sahara; Nobuyuki Kawai; Morio Sato; Akira Ikoma; Hiroki Minamiguchi; Motoki Nakai; Hiroki Sanda; Kouhei Nakata; Taizou Takeuchi; Takami Tanaka; Shintaro Shirai; Tetsuo Sonomura

Objective To evaluate the washout (WO) pattern of serous cystadenomas (SCAs) compared with endocrine tumors (ETs) and intraductal papillary mucinous neoplasm (IPMN). Methods Patients with serous cystadenoma (n = 12), ET (n = 29), and IPMN (n = 35) underwent 4-phase computed tomography CT. Tumors were categorized as hyperdense or hypodense. Computed tomographic values measured were unenhanced attenuation (AU), pancreatic attenuation (A12, 12 seconds), portal attenuation (A35), and equilibrium (A158). Computed tomographic parameters calculated were wash-in (WI) = A12 − AU; WO = A12 − A35; and washout ratio (WOR) = WO/WI × 100/22. Results Hyperdense SCAs had significantly higher WOR than did hyperdense ETs (P = 0.001). Among the 3 hypodense tumors, SCAs had the significantly highest WOR (P < 0.05/3). Relative to the pancreas, the WOR of SCAs were equivalent, whereas the WOR of ETs and IPMNs were significantly lower. Conclusions Hyperdense SCAs had significantly higher WOR than did hyperdense ETs, and hypodense SCAs had the significantly highest WOR among the three.


Journal of Vascular and Interventional Radiology | 2011

Pathologic Evaluation of Damage to Bronchial Artery, Bronchial Wall, and Pulmonary Parenchyma After Bronchial Artery Embolization With N-butyl Cyanoacrylate for Massive Hemoptysis

Akira Ikoma; Nobuyuki Kawai; Morio Sato; Takami Tanaka; Tetsuo Sonomura; Shinya Sahara; Kouhei Nakata; Isao Takasaka; Hiroki Minamiguchi; Motoki Nakai; Ichiro Mori

Histologic evidence of safety after bronchial arterial embolization (BAE) with N-butyl cyanoacrylate (NBCA) should be assured. The present report describes a 78-year-old man with massive hemoptysis from lung cancer who underwent surgical lobectomy 23 days after hemostasis had been achieved via BAE with NBCA. Pathologic examination revealed that NBCA filled the lumen of bronchial branch arteries 143-1,094 μm in diameter from the lobar bronchus to subsegmental bronchus but was not seen in the lumen of the pulmonary artery or pulmonary vein. NBCA induced occlusion of bronchial branch arteries but no necrosis of the bronchial wall or pulmonary parenchyma.


Diagnostic and interventional radiology | 2015

Risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair

Motoki Nakai; Akira Ikoma; Hirotatsu Sato; Morio Sato; Yoshiharu Nishimura; Yoshitaka Okamura

PURPOSE We aimed to identify the risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair (EVAR). METHODS We retrospectively reviewed contrast-enhanced computed tomography (CT) images of 143 patients who were followed for ≥6 months after EVAR. Sac expansion was defined as an increase in sac diameter of 5 mm relative to the preoperative diameter. Univariate and multivariate analyses were performed to identify associated risk factors for late sac expansion after EVAR from the following variables: age, gender, device, endoleak, antiplatelet therapy, internal iliac artery embolization, and preprocedural variables (aneurysm diameter, proximal neck diameter, proximal neck length, suprarenal neck angulation, and infrarenal neck angulation). RESULTS Univariate analysis revealed female gender, endoleak, aneurysm diameter ≥60 mm, suprarenal neck angulation >45°, and infrarenal neck angulation >60° as factors associated with sac expansion. Multivariate analysis revealed endoleak, aneurysm diameter ≥60 mm, and infrarenal neck angulation >60° as independent predictors of sac expansion (P < 0.05, for all). CONCLUSION Our results suggest that patients with small abdominal aortic aneurysms (<60 mm) and infrarenal neck angulation ≤60° are more favorable candidates for EVAR. Intraprocedural treatments, such as prophylactic embolization of aortic branches or intrasac embolization, may reduce the risk of sac expansion in patients with larger abdominal aortic aneurysms or greater infrarenal neck angulation.


Journal of Vascular and Interventional Radiology | 2012

Endovascular Stenting and Stent-graft Repair of a Hemorrhagic Superior Mesenteric Artery Pseudoaneurysm and Dissection Associated with Pancreaticoduodenectomy

Motoki Nakai; Hirotatsu Sato; Morio Sato; Akira Ikoma; Hiroki Sanda; Kohei Nakata; Hiroki Minamiguchi; Nobuyuki Kawai; Tetsuo Sonomura; Yoshiharu Nishimura; Yoshitaka Okamura

This report presents a 73-year-old woman with intraperitoneal bleeding from a superior mesenteric artery (SMA) pseudoaneurysm and dissection after pancreaticoduodenectomy (PD). A self-expanding bare metal stent was placed in the distal SMA across the area of dissection, and a stent-graft was subsequently placed across the pseudoaneurysm emerging from the proximal site by overlapping the bare stent, resulting in complete exclusion of the pseudoaneurysm and control of the dissection. Bleeding was controlled after the endovascular procedure. The combination of endovascular stenting and stent-graft repair is feasible and useful in comorbid cases of SMA pseudoaneurysm and dissection.


World Journal of Radiology | 2012

Inferior pancreaticoduodenal artery aneurysm treated with coil packing and stent placement.

Akira Ikoma; Motoki Nakai; Morio Sato; Nobuyuki Kawai; Takami Tanaka; Hiroki Sanda; Kouhei Nakata; Hiroki Minamiguchi; Tetsuo Sonomura

Two cases with a pancreaticoduodenal arterial aneurysm accompanied with superior mesenteric artery (SMA) stenosis were previously described and both were treated surgically. However, for interventional treatment, securing a sufficient blood supply to the SMA should be a priority of treatment. We present the case of a 71-year-old male with a 20 mm diameter pancreaticoduodenal arterial aneurysm accompanied by SMA stenosis at its origin. The guidewire traverse from SMA to the aneurysm was difficult because of the tight SMA stenosis; however, the guidewire traverse from the celiac artery was finally successful and was followed by balloon angioplasty using a pull-through technique, leading to stent placement. Thereafter, coil packing through the SMA achieved eradication of the aneurysm without bowel ischemia. At the last follow-up computed tomography 8 mo later, no recurrence of the aneurysm was confirmed. The pull-through technique was useful for angioplasty for tight SMA stenosis in this case.


Journal of Vascular and Interventional Radiology | 2011

Balloon occlusion retrograde transvenous obliteration for inferior mesenteric vein-systemic shunt.

Hiroki Minamiguchi; Nobuyuki Kawai; Morio Sato; Akira Ikoma; Munehisa Sawa; Tetsuo Sonomura; Shinya Sahara; Kouhei Nakata; Takami Tanaka; Isao Takasaka; Motoki Nakai

Two cases of portosystemic encephalopathy caused by an inferior mesenteric vein (IMV)-internal iliac vein shunt and an IMV-renal vein shunt are presented. IMV and systemic varicosity consisted of a first functional segment, a stagnant segment, and a second functional segment. Both patients underwent balloon occlusion retrograde transvenous obliteration (BRTO), using a microcatheter, to occlude the stagnant segment selectively. Although transient portal vein thrombosis was observed in case 1 and aggravation of esophageal varices was observed in case 2, these complications were tolerable. Following BRTO, the portosystemic encephalopathy in both cases resolved, and serum ammonia levels, although elevated, remained within the normal range.

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Motoki Nakai

Wakayama Medical University

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Morio Sato

Wakayama Medical University

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Tetsuo Sonomura

Wakayama Medical University

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Nobuyuki Kawai

Wakayama Medical University

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Kouhei Nakata

Wakayama Medical University

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Hiroki Minamiguchi

Wakayama Medical University

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Hiroki Sanda

Wakayama Medical University

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Hirotatsu Sato

Wakayama Medical University

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Takami Tanaka

Wakayama Medical University

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