Masao Hamuro

Identifying Feeding Arteries During TACE of Hepatic Tumors: Comparison of C-Arm CT and Digital Subtraction Angiography

OBJECTIVE This study compares the diagnostic accuracy of C-arm CT with digital subtraction angiography (DSA) in identifying tumor-feeding arteries during superselective transarterial chemoembolization (TACE). MATERIALS AND METHODS Thirty-three consecutive patients with hepatocellular carcinoma (HCC) underwent superselective TACE using a flat-detector angiographic system. Angiographic operators determined which feeding arteries were potentially supplying the target tumor. When two or more feeding arteries were possible, all were included. Superselective DSA and C-arm CT were sequentially performed for each studied artery. Four independent observers separately viewed the DSA and C-arm CT images and used a 5-point grading scale to determine whether a studied artery supplied the target tumor. Diagnostic performance was compared using receiver operating characteristic (ROC) analysis. Sensitivity, specificity, and accuracy were calculated for arteries rated as definite or probable tumor feeders. Iodized oil accumulation on follow-up CT was the reference standard. RESULTS We examined 58 possible feeding arteries in 33 patients. Among the studied arteries, follow-up CT confirmed that 33 were verified tumor-feeding arteries, and the remaining 25 were not. C-arm CT resulted in a significantly larger area under the ROC curve (A(z) = 0.995) compared with DSA (A(z) = 0.841). The sensitivity, specificity, and accuracy of C-arm CT (96.9%, 97.0%, and 96.9%, respectively) were significantly higher than those for DSA (77.2%, 73.0%, and 75.4%). CONCLUSION C-arm CT is superior to DSA for identifying tumor-feeding arteries during superselective TACE for HCC.

Detection of hepatocellular carcinoma: comparison of angiographic C-arm CT and MDCT.

OBJECTIVE The aim of this study was to compare the accuracy, sensitivity, and positive predictive value of C-arm CT with those of MDCT in the detection of hepatocellular carcinoma. MATERIALS AND METHODS We retrospectively evaluated the cases of 50 patients with nodules of hepatocellular carcinoma who underwent biphasic MDCT and selective C-arm CT with flat-detector angiographic systems. We evaluated arterial phase C-arm CT images and the corresponding biphasic MDCT images of 59 hepatic areas in 50 patients. Three independent blinded observers rated both sets of images using a detection confidence scale. The diagnostic accuracy of the two techniques was compared on the basis of area under alternative free-response receiver operating characteristic curve (A(1)). Focal accumulation of iodized oil was the reference standard. RESULTS Accuracy was significantly higher for C-arm CT (A(1) = 0.830) than for MDCT (A(1)= 0.618) for lesions smaller than 10 mm in diameter (p < 0.001), but the accuracy of the two techniques did not differ significantly for lesions measuring 10 mm or larger. C-arm CT was significantly more sensitive than MDCT in the detection of lesions 20 mm or smaller (74.1% vs 34.0% for lesions < 10 mm [p < 0.001]; 94.7% vs 77.1% for lesions 10-20 mm [p < 0.001]). The positive predictive values of the two techniques did not differ significantly irrespective of lesion size. CONCLUSION Compared with biphasic MDCT, C-arm CT depicted hepatocellular carcinoma lesions smaller than 10 mm with more accuracy and those 20 mm and smaller with more sensitivity. The two techniques were equally accurate in the detection of hepatocellular carcinoma lesions 10 mm in diameter and larger.

Correlation between Dynamic Computed Tomographic and Histopathological Findings in the Diagnosis of Small Hepatocellular Carcinoma

Background/Aims: To determine the characteristic image findings on dynamic computed tomography (CT) for small hepatocellular carcinoma (HCC), we evaluated the correlation of histopathological and radiological findings with respect to the angioarchitecture in small HCCs. Methods: CT and early- and late-phase dynamic CT findings of 80 small HCCs (≤3 cm) were divided into iso-, high, low, and mixed density. We studied the correlation between the imaging findings and the histopathological findings as follows: differentiation grade; presence of fibrous capsule; presence of Glisson’s sheath, and growth pattern. Results: High-density early-phase CT and low-density late-phase CT correlated significantly with moderately/poorly differentiated HCCs, which have a fibrous capsule, no Glisson’s sheath, and an expansive growth pattern. In contrast, well-differentiated HCCs with a Glisson’s sheath and a replacing pattern (early HCC) appeared as iso-dense lesions in the early and late phases. Well-differentiated HCCs (non-early wHCC) demonstrated various density images in the early phase and low-density images in the late phase. Conclusions: Dynamic CT is an economic and simple diagnostic tool for planning treatment of small HCC lesions because of the multistep nature of HCC carcinogenesis and the hemodynamic changes of tumor blood flow.

Dual Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varix Draining into the Left Adrenal Vein and Left Inferior Phrenic Vein

A 66-year-old woman with a gastric varix, draining into a dilated left adrenal vein and a left inferior phrenic vein, was treated with dual balloon-occluded retrograde transvenous obliteration (B-RTO). Under balloon occlusion of the left adrenal vein and the left inferior phrenic vein, retrograde injection of a sclerosant (5% ethanolamine oleate) into the gastric varix was performed. Two weeks later, disappearance of flow in the gastric varix was confirmed on endoscopic ultrasound examination.

New oily agents for targeting chemoembolization for hepatocellular carcinoma.

AbstractPurpose: The evaluation of new oily agents for targeting chemoembolization for hepatocellular carcinoma. Methods: Five types of oily preparation were injected into the hepatic artery of 54 rabbits inoculated with VX2 carcinoma cells in order to evaluate (1) the safety of these preparations, (2) their histologic distribution and the amount of agents remaining at tumor sites, and (3) computed tomographic (CT) images obtained. Of these preparations, three were made by mixing non-iodinated poppy seed oil and a thickener and then adjusted to have a viscosity lower than, equal to, or higher than that of lipiodol. A fourth preparation was a mixture of lipiodol and a thickener with a higher viscosity than lipiodol alone, and the fifth preparation are lipiodol alone. Results: (1) No injury to the hepatic parenchyma was observed hematologically or histologically. (2) With increase in the viscosity, a significantly larger amount of agent remained at the tumor site. No agent was present at normal sites 14 days after intraarterial injection, regardless of which preparation was given. (3) On CT scans following intraarterial injection, tumor cells were visibly deeply stained in the non-iodinated preparation groups, while the lipiodol groups were not evaluable because of excessively high attenuation. Conclusion: The non-iodinated oily preparations and highly viscous oily preparations developed in the present study were more useful than lipiodol for treatment of hepatic tumors.

Pseudoaneurysm of the dorsal pancreatic artery with obstruction of the celiac axis after pancreatoduodenectomy: report of a case.

Pancreatoduodenectomy can be difficult in patients with obstruction of the celiac axis because of the development of collateral arteries around the head of the pancreas. Bleeding from a pseudoaneurysm is a rare and serious complication of pancreatoduodenectomy. We report a case of a pseudoaneurysm of an enlarged dorsal pancreatic artery, which formed as a result of obstruciton of the celiac axis after pancreatoduodenectomy. We assumed that a weakness in the wall of this dorsal pancreatic artery caused by the dissection led to the formation of the aneurysm. Although transcatheter arterial embolization (TAE) could not treat the aneurysm or stop bleeding from the aneurysm completely, it achieved transient hemostasis, whereby the patient’s condition improved, making laparotomy safe. This case demonstrates that the dissection of arteries that have developed around the head of the pancreas must be considered in patients with obstruction of the celiac axis.

Selective balloon-occluded retrograde transvenous obliteration of gastric varix with preservation of major portacaval shunt.

1All authors: Department of Radiology, Osaka City University Graduate School of Medicine, 1-4-3, Asahimachi, Abeno-bu, Osaka, Japan 545-8585. Address correspondence to N. Nishida (norifumin@med.osakacu.ac.jp). alloon-occluded retrograde transvenous obliteration (B-RTO) has been performed instead of endoscopic and surgical treatment in the management of gastric varix. The procedure is indicated for gastric varix with a major portacaval shunt, such as a gastrorenal shunt or a shunt involving the left inferior phrenic vein, and usually obliterates the gastric varix and the connecting major portacaval shunt. BRTO is safe, feasible, and effective in the treatment of patients with gastric varix; however, aggravation of esophageal varix is an important complication caused by increasing portal pressure [1–3]. We report the first case, to our knowledge, of selective B-RTO with preservation of the major portacaval shunt. MDCT during splenic and superior mesenteric arterial portography was useful for confirming the morphologic features and developing a precise therapeutic plan.

Local Inductive Heating Method Using Novel High-Temperature Implant for Thermal Treatment of Luminal Organs

The authors have previously proposed both a regional heating system, which introduced auxiliary electrodes, and a local inductive heating system, which introduced high-temperature-rise implants. In this paper, we present two novel types of high-temperaturerise implants aiming at luminal organ treatments, namely, a coaxial needle and a stent. Since hot-spot generation may degrade the accuracy of temperature measurements when developing these inductive heating implants, a simple method using a high-conductivity eddy-current absorber such as an aluminum foil is proposed. This is suggested based on theoretical investigations using the 3-D finite-element method and experiments. The heating tests of the novel folding-type implants suggested by medical doctors were conducted at a frequency of 4.0 MHz and an output power of 500 W using the proposed EC A. It was found that in the case of the coaxial-needle-type implant, a high temperature rise of more than 60 omicronC can be achieved.

Successful embolization of a ruptured pancreaticoduodenal artery aneurysm associated with the median arcuate ligament syndrome

Celiac axis compression caused by the median arcuate ligament (MAL) syndrome is a rare entity. Occasionally, the resultant celiac axis stenosis increases blood flow in the pancreaticoduodenal arcade, and the consequent volume overload can lead to arterial dilatation and aneurysm formation.[1] Recently, transcatheter embolization has become an alternative initial treatment for ruptured aneurysms.[2] Previously reported cases have indicated that ruptured aneurysms should be isolated by coils or other embolic agents.[3] However, efforts at such isolation carry the potential risk of re-bleeding if the ruptured aneurysm has other arterial communications.

Hepatocellular carcinoma extending into the portal vein: restoration of extended-term patency by placement of uncovered Wallstents.

A 74-year-old man presented with hepatocellular carcinoma extending into the main portal vein. Two bare Wallstents were placed to maintain portal vein patency. The main portal vein remained patent for 6 months after treatment. No serious complications were observed during or after treatment.