Kouhei Nakata

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

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.

Effectiveness of Hepatic Arterial Embolization on Radiofrequency Ablation Volume in a Swine Model: Relationship to Portal Venous Flow and Liver Parenchymal Pressure

PURPOSE To evaluate the effectiveness of transcatheter arterial embolization (TAE) on radiofrequency (RF) ablation volume and compare portal vein (PV) flow and liver parenchymal pressure before and after treatment. MATERIALS AND METHODS Eight healthy female swine were divided into four groups to be treated with RF ablation alone (RF-only group), RF ablation after TAE with gelatin sponge particles (GSPs; RF/TAE group), RF ablation after TAE with Lipiodol plus GSPs (RF/TAE/Lipiodol group), and PV embolization (PVE) with GSPs after TAE with Lipiodol plus GSPs (RF/TAE/Lipiodol/PVE group). Five ablations were created in each swine, with 10 ablations per group. A 2-cm expandable LeVeen needle electrode was used for RF ablation. RESULTS The greatest ablation volume (18,410.1 mm(3) +/- 3,986.4) was observed in the RF/TAE/Lipiodol/PVE group. Of the RF-only, RF/TAE, and RF/TAE/Lipiodol groups, the RF/TAE/Lipiodol group (14,835.5 mm(3) +/- 2,743.2) had a significantly larger ablation volume than the RF-only (8,002.6 mm(3) +/- 2,788.3) and RF/TAE groups (10,398.5 mm(3) +/- 2965.8; P < .05/3). PV pressures increased significantly after TAE (P < .01) compared with the pressure before TAE in the RF/TAE/Lipiodol and RF/TAE/Lipiodol/PVE groups, but not in the RF/TAE group. A marked increase in liver parenchymal pressure was seen during RF ablation; however, there were no significant differences among groups. Accumulation of Lipiodol was noted in the sinusoids in the RF/TAE/Lipiodol and RF/TAE/Lipiodol/PVE groups. CONCLUSIONS TAE with blockade of PV flow before RF ablation was associated with greater ablation volumes. Liver parenchymal pressure showed no correlation with increased ablation volume.

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

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.

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

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.

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

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.

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

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.

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

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.

Emergency balloon-occluded retrograde transvenous obliteration of ruptured gastric varices.

AIM To evaluate the effectiveness and safety of emergency balloon-occluded retrograde transvenous obliteration (BRTO) for ruptured gastric varices. METHODS Emergency BRTO was performed in 17 patients with gastric varices and gastrorenal or gastrocaval shunts within 24 h of hematemesis and/or tarry stool. The gastric varices were confirmed by endoscopy, and the gastrorenal or gastrocaval shunts were identified by contrast-enhanced computed tomography (CE-CT). A 6-Fr balloon catheter (Cobra type) was inserted into the gastrorenal shunt via the right internal jugular vein, or into the gastrocaval shunt via the right femoral vein, depending on the varices drainage route. The sclerosant, 5% ethanolamine oleate iopamidol, was injected into the gastric varices through the catheter during balloon occlusion. In patients with incomplete thrombosis of the varices after the first BRTO, a second BRTO was performed the following day. Patients were followed up by endoscopy and CE-CT at 1 d, 1 wk, and 1, 3 and 6 mo after the procedure, and every 6 mo thereafter. RESULTS Complete thrombosis of the gastric varices was not achieved with the first BRTO in 7/17 patients because of large gastric varices. These patients underwent a second BRTO on the next day, and additional sclerosant was injected through the catheter. Complete thrombosis which led to disappearance of the varices was achieved in 16/17 patients, while the remaining patient had incomplete thrombosis of the varices. None of the patients experienced rebleeding or recurrence of the gastric varices after a median follow-up of 1130 d (range 8-2739 d). No major complications occurred after the procedure. However, esophageal varices worsened in 5/17 patients after a mean follow-up of 8.6 mo. CONCLUSION Emergency BRTO is an effective and safe treatment for ruptured gastric varices.

Percutaneous Osteoplasty with a Bone Marrow Nail for Fractures of Long Bones: Experimental Study

PURPOSE To develop percutaneous osteoplasty with the use of a bone marrow nail for fixation of long-bone fractures, and to evaluate its feasibility and safety in vivo and in vitro. MATERIALS AND METHODS Six long bones in three healthy swine were used in the in vivo study. Acrylic cement was injected through an 11-gauge bone biopsy needle and a catheter into a covered metallic stent placed within the long bone, creating a bone marrow nail. In the in vitro study, we determined the bending, tug, and compression strengths of the acrylic cement nails 9 cm long and 8 mm in diameter (N = 10). The bending strength of the artificially fractured bones (N = 6) restored with the bone marrow nail and cement augmentation was then compared with that of normal long bones (N = 6). RESULTS Percutaneous osteoplasty with a bone marrow nail was successfully achieved within 1 hour for all swine. After osteoplasty, all swine regained the ability to run until they were euthanized. Blood tests and pathologic findings showed no adverse effects. The mean bending, tug, and compression strengths of the nail were 91.4 N/mm(2) (range, 75.0-114.1 N/mm(2)), 20.9 N/mm(2) (range, 6.6-30.4 N/mm(2)), and 103.0 N/mm(2) (range, 96.3-110.0 N/mm(2)), respectively. The bending strength ratio of artificially fractured bones restored with bone marrow nail and cement augmentation to normal long bone was 0.32. CONCLUSIONS Percutaneous osteoplasty with use of a bone marrow nail and cement augmentation appears to have potential in treating fractures of non-weight-bearing long bones.

Three benefits of microcatheters for retrograde transvenous obliteration of gastric varices

AIM To evaluate the usefulness of the microcatheter techniques in balloon-occluded retrograde transvenous obliteration (BRTO) of gastric varices. METHODS Fifty-six patients with gastric varices underwent BRTOs using microcatheters. A balloon catheter was inserted into gastrorenal or gastrocaval shunts. A microcatheter was navigated close to the varices, and sclerosant was injected into the varices through the microcatheter during balloon occlusion. The next morning, thrombosis of the varices was evaluated by contrast enhanced computed tomography (CE-CT). In patients with incomplete thrombosis of the varices, a second BRTO was performed the following day. Patients were followed up with CE-CT and endoscopy. RESULTS In all 56 patients, sclerosant was selectively injected through the microcatheter close to the varices. In 9 patients, microcoil embolization of collateral veins was performed using a microcatheter. In 12 patients with incomplete thrombosis of the varices, additional injection of sclerosant was performed through the microcatheter that remained inserted overnight. Complete thrombosis of the varices was achieved in 51 of 56 patients, and the remaining 5 patients showed incomplete thrombosis of the varices. No recurrence of the varices was found in the successful 51 patients after a median follow up time of 10.5 mo. We experienced one case of liver necrosis, and the other complications were transient. CONCLUSION The microcatheter techniques are very effective methods for achieving a higher success rate of BRTO procedures.