Keitaro Sofue

MR imaging of hepatic metastasis in patients with malignant melanoma: evaluation of suspected lesions screened at contrast-enhanced CT.

PURPOSE To evaluate the magnetic resonance (MR) imaging feature of suspected hepatic metastasis in patients with malignant melanoma which showed intermediate findings on screened contrast-enhanced computed tomography (CECT). MATERIALS AND METHODS MR imaging was performed in 38 patients (22 men, 16 women; mean age, 58 years) whose CECT findings were intermediate. Hepatic metastases had been diagnosed on MR imaging in 23 of the 38 patients. Verification of hepatic metastasis was made by histological examination: ultrasonographic-guided needle biopsy (n=3), autopsy (n=3), and surgical resection (n=1), or by an obvious progression in number and/or size of the lesions on follow-up MR imaging (n=24). Two diagnostic radiologists reviewed MR images by consensus. The median follow-up duration was 14.2 months. RESULTS Abnormal findings were detected in 31 patients on MR images, and undetected in the remaining seven patients resulting in false-positive on CECT. The mean size of the lesion was 11.0mm. False-positive results were obtained in two lesions which disappeared on follow-up MR imaging. In six patients, lesions were considered as hepatic cysts on MR images. As a result, a total of 35 hepatic metastases were detected on MR images. Of these, 18 patients demonstrated typical melanotic appearance on MR images which showed shortened T1 and T2 relaxation times, and five patients demonstrated atypical melanotic appearance. In 16 patients, extra-hepatic metastases were also developed. CONCLUSION MR imaging could rule out hepatic metastasis in patients with malignant melanoma which showed intermediate findings on screened CECT, and could detect additional extra-hepatic metastases.

Evaluation of hypervascular hepatocellular carcinoma in cirrhotic liver: comparison of different concentrations of contrast material with multi-detector row helical CT--a prospective randomized study.

PURPOSE To evaluate two different iodine concentrations of contrast material for detecting hypervascular hepatocellular carcinomas (HCCs) in cirrhotic liver by multi-detector row helical CT (MDCT) when a fixed contrast material volume and injection rate is used. MATERIALS AND METHODS Institutional Review Board approval was obtained, and informed consent was obtained from all patients. In this prospective study, 105 patients were randomly assigned a group A (an iodine concentration of 300 mg I/mL), and a group B (an iodine concentration of 370 mg I/mL). In both groups the volume of contrast material was 100 mL and the injection rate was 4 mL/s. Fifty-two patients had 122 hypervascular HCCs. The diagnosis of HCCs was established histopathologically (n=24) and by imaging findings (n=98). Three readers independently analyzed four image sets: an arterial phase (AP), a portal phase (PP), an equilibrium phase (EP), and combined all three phase images set. Sensitivity, specificity, and diagnostic accuracy were calculated by receiver operating characteristic (ROC) analysis. RESULTS The mean sensitivity for detecting hypervascular HCCs of the AP set, EP set, and combination set in group B (0.94, 0.81, and 0.93) was significantly higher than in group A (0.84, 0.69, and 0.80). Area under the ROC curve of the AP set and the combination set in group B (0.974 and 0.981) was significantly higher than in group A (0.939 and 0.958). CONCLUSION At the same contrast material volume and injection rate, higher iodine concentration of contrast material was effective for detecting hypervascular HCCs by MDCT.

Guidelines for the use of NBCA in vascular embolization devised by the Committee of Practice Guidelines of the Japanese Society of Interventional Radiology (CGJSIR), 2012 edition

Abstract Cyanoacrylates are a group of fast-acting adhesives. They form low viscosity liquids in the monomer state and instantly polymerize to become adhesive upon contact with ionic substances. Since the 1950s, they have been used around the world for industrial and household purposes. N-butyl cyanoacrylate (NBCA) is a cyanoacrylate that is commonly used for medical care, and the closure of skin wounds with NBCA has been found to promote hemostasis. However, in Japan, the intravascular injection of NBCA is considered to be off-label use, except during the treatment of gastric varices under endoscopy. The use of NBCA in embolotherapy is considered when the target vessels cannot be cannulated superselectively, for vascular diseases that require long segments of the target vessel to be embolized, or for patients in a hypocoagulable state. NBCA-based embolotherapy can be used to treat vascular malformations, acute hemorrhaging, tumors, and venous disease. The complications associated with NBCA-based embolotherapy include tissue ischemia, hemorrhaging, systemic or local reactions, and catheter adhesion to blood vessels. NBCA is mixed with Lipiodol to make it radiopaque and to adjust its polymerization time. Since there are various technical aspects to performing NBCA-based embolotherapy safely, it should be carried out by, or with the assistance of, proficient interventional radiologists.

Right portal vein embolization with absolute ethanol in major hepatic resection for hepatobiliary malignancy

This study aimed to evaluate the safety and efficacy of preoperative right portal vein embolization (PVE) with absolute ethanol in patients with hepatobiliary malignancies.

Life-threatening cerebral edema caused by acute occlusion of a superior vena cava stent.

A71-year-old man with advanced lung cancer developed a life-threatening cerebral edema caused by the acute occlusion of a superior vena cava (SVC) stent and was successfully treated by an additional stent placement. Although stent occlusion is a common early complication, no life-threatening situations have been reported until now. Our experience highlights the fact that acute stent occlusion can potentially lead to the complete venous shutdown of the SVC, resulting in life-threatening cerebral edema, after SVC stent placement. Immediate diagnosis and countermeasures are required.

Successful balloon-occluded retrograde transvenous obliteration for bleeding duodenal varices using cyanoacrylate

A 76-year-old woman with hepatitis C cirrhosis presented with tarry stools and hematemesis. An endoscopy demonstrated bleeding duodenal varices in the second portion of the duodenum. Contrast-enhanced computed tomography revealed markedly tortuous varices around the wall in the duodenum. Several afferent veins appeared to have developed, and the right ovarian vein draining into the inferior vena cava was detected as an efferent vein. Balloon-occluded retrograde transvenous obliteration (BRTO) of the varices using cyanoacrylate was successfully performed in combination with the temporary occlusion of the portal vein. Although no previous publications have used cyanoacrylate as an embolic agent for BRTO to control bleeding duodenal varices, this strategy can be considered as an alternative procedure to conventional BRTO using ethanolamine oleate when numerous afferent vessels that cannot be embolized are present.

Safety and Efficacy of Primary Metallic Biliary Stent Placement with Tract Embolization in Patients with Massive Ascites: A Retrospective Analysis of 16 Patients

PURPOSE To evaluate the safety and efficacy of primary metallic biliary stent placement with tract embolization in patients with massive ascites. MATERIALS AND METHODS Sixteen patients with malignant biliary obstruction and massive ascites (age range, 44-79 y; median age, 59 y) were treated with primary percutaneous stent placement with tract embolization. These patients were unsuitable candidates for endoscopic intervention. Etiologies of biliary obstruction were gastric cancer with hilar nodal metastases (n = 9), pancreatic carcinoma (n = 5), cholangiocarcinoma (n = 1), and gallbladder carcinoma (n = 1). Eight patients had nonhilar lesions and the remaining eight had hilar lesions. Percutaneous accesses to the biliary system and stent placements were performed in a one-step procedure, and catheters were removed with tract embolization with metallic coils. RESULTS Stent placement and tract embolization were successful in all patients, without external drainage catheters left in place. Significant reduction of serum bilirubin level was observed in 14 patients (87.5%). No bile peritonitis or intraperitoneal hemorrhage occurred. Major complications included postprocedural cholangitis (12.5%), bloody bowel discharge (6.2%), and right pleural effusion (25.0%). One patient who died 19 days after intervention was deemed to represent a procedure-related mortality. During the survival period (range, 19-175 d; median, 66 d), stent occlusion was noted in two patients at 6 and 159 days after the procedure. Primary stent patency was achieved in 14 patients (87.5%). CONCLUSIONS Primary biliary stent placement with tract embolization is technically safe and offers an effective palliative treatment option for patients with malignant biliary obstruction and massive ascites when endoscopic intervention is not possible.

Smoking Status and the Incidence of Pancreatic Cancer Concomitant With Intraductal Papillary Mucinous Neoplasm.

Objectives The effect of smoking status on the incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN) has not been clarified. This study investigated the association of smoking status with PDAC concomitant with IPMN. Methods The subjects were 124 consecutive patients undergoing resection of IPMNs (intraductal papillary mucinous adenoma (IPMA): N = 77, invasive IPMN: N = 31, and PDAC with IPMN: N = 16) between April 2008 and October 2015. The associations between smoking status (never/former/current smoker) or cumulative pack-years (0–19/20–39/≥40) and the incidence of PDAC concomitant with IPMN or invasive IPMN were evaluated. Results Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN (PDAC with IPMN vs IPMN alone; P = 0.004, PDAC with IPMN vs IPMA; P = 0.004, PDAC with IPMN vs invasive IPMN; P = 0.04, respectively), but not that of invasive IPMN (invasive IPMN vs IPMA; P = 0.85). Cumulative pack-years were higher in patients who had PDAC concomitant with IPMN than in patients with invasive IPMN (P = 0.04). Cumulative pack-years were not associated with smoking status (current vs former). Conclusions Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN. Cessation of smoking may be recommended for patients with IPMN.

Ultrasonography-guided central venous port placement with subclavian vein access in pediatric oncology patients.

BACKGROUND/PURPOSE To evaluate the technical success and complications of image-guided central venous port (CVP) placement with subclavian vein (SCV) access in pediatric oncology population. MATERIALS AND METHODS Ninety-two children (52 boys, 40 girls; mean age, 8.5 years) underwent CVP implantation under local anesthesia with conscious sedation. SCV access was firstly attempted under ultrasonographic guidance and CVP implantation was performed under fluoroscopic guidance. Technical success, peri-procedural (<24h) complication, and post-procedural (>24h) complication were assessed. RESULTS In total, 102 CVPs were implanted in 92 children with a mean catheter time of 364 days (total, 38,224 days; range, 14-1911 days). In three small children, conversion of SCV access to internal jugular vein access yielded a primary technical success rate of 97.1% and overall technical success rate of 100%. Three minor peri-procedural complications were observed (2.9%) and seven post-procedural infectious complications occurred (infection rate, 6.7%; 0.18/1000 catheter days). No pneumothorax, catheter malposition, venous thrombosis, or mortality occurred. CONCLUSION Image-guided CVP placement with SCV access in a pediatric population was performed with high technical success and low complication rate without general anesthesia. This procedure can be taken into account as a choice of procedure when internal jugular venous access is not possible.

Inhibition of Growth in a Rabbit VX2 Thigh Tumor Model with Intraarterial Infusion of Carbon Dioxide–Saturated Solution

PURPOSE To evaluate the efficacy of intraarterial infusion of CO2-saturated solution in rabbit VX2 thigh tumors. MATERIALS AND METHODS Fourteen Japanese white rabbits had VX2 tumors implanted in the right femoral muscle 3 weeks before intraarterial infusion. Rabbits were divided into control and CO2 groups (n = 7 each). Fifty milliliters of solution (saline solution and CO2-saturated solution for the control and CO2 groups, respectively) was administered via a 24-gauge catheter in the ipsilateral iliac artery close to the feeding artery of the VX2 tumor. All rabbits were killed for tumor harvest on day 3 after the procedure. Tumor volume was evaluated with in vivo direct caliper measurement and contrast-enhanced computed tomography (CT). Tumor apoptotic changes were examined by DNA fragmentation assay and immunoblot analysis. The tumor growth ratio and apoptotic cell rate were analyzed. RESULTS Body weight was equally increased in both groups, but the mean tumor growth ratio was significantly decreased in the CO2 group compared with the control group (-9.5% ± 7.9 vs 27.2% ± 6.6 and 4.1% ± 4.4 vs 35.7% ± 4.5 measured by calipers and contrast-enhanced CT, respectively; P < .01). Apoptotic activity in the CO2 group was higher than in the control group (number of apoptotic cells per area, 215.0 ± 58.7 vs 21.8 ± 5.4; adjusted relative density of cleaved caspase-3, 0.23 ± 0.07 vs 0.04 ± 0.01; P < .01). CONCLUSIONS Intraarterial infusion of CO2-saturated solution inhibits rabbit VX2 thigh tumor growth by activation of apoptotic cell death through cleaved caspase-3 upregulation.