Genetic variation and local differences in Pacific cod Gadus macrocephalus around Japan.

The population structure of the Pacific cod Gadus macrocephalus was examined using 15 microsatellite loci and mitochondrial DNA (ND2 region). In total, 274 individuals were sampled from 16 locations around Japan to estimate the level of genetic differentiation and effective population size (Ne ). Pairwise FST , analysis of molecular variance and Bayesian clustering analysis suggested the presence of two genetically distinct groups in waters around Japan, with a higher Ne value in the eastern group than in the western group. A possible factor that restricts gene flow between groups may be related to the water temperature differences in the south-western part of the Sea of Japan, where the Tsushima Warm Current flows around the area inhabited by the western group, which may limit migration between the west and east.

Bilateral chylothorax following radical neck dissection.

Bilateral chylothorax as a complication of radical neck dissection is extremely rare, but it is potentially serious and sometimes fatal. We found only 14 cases reported in the English literature. Here, we report a case of bilateral chylothorax following right modified and left radical neck dissections that was successfully treated with conservative management.

[Angiographic findings of hemodialysis access insufficiency].

One hundred forty-six angiographic findings of malfunctioning internal arteriovenous fistulas without any history of interventional procedures were reviewed. Angiographies demonstrated 110 cases of stenosis, 72 of occlusion, 5 of venous varicosity, and 13 of venous aneurysm. Of 182 stenotic lesions, 118 (65%) lesions (74 venous stenoses: 67%; 44 venous occlusions: 61%) were revealed within five centimeters of anastomoses. In 4 of 5 cases of varicosity, proximal venous occlusions were demonstrated. On the other hand, interventional procedures were performed in 81 cases of stenoses and 14 of occlusions in the manner of PTA and fibrinolysis. The initial success rate was 90% in stenotic lesions and 71% in occlusive lesions, not a statistically significant difference. Furthermore, there was no statistically significant difference in initial success rates according to anatomical location and lesion length. Although there was no statistically significant difference according to the angiographic findings of lesions, we would like to emphasize the importance of correct understanding of anatomical changes in the dialysis shunt and of early intervention to improve the initial success rate of PTA.

Visualization of tumor vessels in renal tumors. Comparison between power Doppler ultrasonography and angiography.

PURPOSE: To compare the ability of power Doppler ultrasonography (PDUS) with that of renal angiography for assessment of renal tumor vessels. MATERIAL AND METHODS: We performed PDUS and angiography in 52 histologically proven renal parenchymal tumors (50 renal cell carcinomas (RCCs) and 2 oncocytomas), and compared vascularity on PDUS and angiography. The vascularity of PDUS was graded as follows: grade 0-- no recognizable tumor vessel; grade 1-- hypovascular to surrounding renal interlobar arteries; grade 2-- hyper- or isovascular to surrounding renal interlobar arteries. RESULTS: With PDUS, 41 tumors were grade 2 and 11 were grade 1. With angiography, 44 lesions had iso/hypervascular pattern, 6 hypovascular pattern, and 2 were judged to be avascular. Among 44 iso/hypervascular tumors, 41 were grade 2, and 3 were grade 1. These latter 3 were located deeper than 7 cm. Six hypovascular tumors and 2 avascular tumors were grade 1. The 2 avascular tumors were small and hypovascular. The kappa-level of agreement was 0.81. CONCLUSION: There was very good agreement between PDUS and angiography in visualizing renal tumor vessels. PDUS appears appropriate for assessing renal tumor vascularity as compared to angiography in small and hypovascular lesions, but deep location reduced the detectability of tumor vessels with PDUS.

[Transcatheter arterial embolization of aneurysmal-type renal arteriovenous fistula: a case report].

We report a case of aneurysmal-type renal arteriovenous fistula, which was successfully treated with transcatheter arterial embolization (TAE). A 73-year-old woman was referred to our hospital because of an incidental abnormal renal mass detected by computed tomography (CT). CT scan showed a round mass (4 x 3 x 3 cm) in the right kidney. Magnetic resonance (MR)-angiography and angiography revealed an aneurysmal type renal arteriovenous fistula (AVF). The patient was treated with TAE using detachable coils. CT, MR-angiography and angiography are useful means for the diagnosis of renal arteriovenous fistula. TAE is a powerful treatment for renal arteriovenous fistula.

Double-phase helical CT of small renal parenchymal neoplasms: correlation with pathologic findings and tumor angiogenesis.

PURPOSE: To correlate the enhancement pattern of double-phase helical computed tomography (CT) of small renal parenchymal neoplasms with pathologic findings and tumor angiogenesis, and evaluate whether the enhancement pattern would be useful in differentiating the histomorphologic types of small renal parenchymal neoplasms. MATERIALS AND METHODS: Double-phase helical CT (5 mm slice) of the corticomedullary phase (CMP) and late nephrographic phase (NP) was performed in 40 surgically resected renal neoplasms <3.5 cm. The patterns of CT attenuation value and homogeneity were correlated with the subtypes of neoplasms, microvessel density, and the existence of intratumoral necrosis or hemorrhage. RESULTS: Clear cell renal cell carcinomas (RCC) (n = 29) showed a peak attenuation value in the CMP of >100 HU [Hounsfield units]. Chromophobe cell RCC (n = 2) showed a peak attenuation value in the CMP of <100 HU. Papillary RCC (n = 5) showed a gradual enhancement with the attenuation value in the CMP of <100 HU. However oncocytomas (n = 2) and metanephric adenomas (n = 2) also showed patterns similar to these subtypes of RCC. The degree of enhancement in the CMP correlated with microvessel density (r = 0.87). All tumors with an homogeneous enhancement pattern did not show necrosis or hemorrhage on histologic specimen. CONCLUSION: The enhancement pattern in double-phase helical CT was different among the subtypes of RCC, and correlated with microvessel density or the existence of intratumoral necrosis or hemorrhage. However it did not differentiate between RCC and other solid tumors.

Computed tomography during arterial portography under temporary balloon occlusion of the hepatic artery: evaluation of pseudolesions caused by arterio-portal venous shunts.

BACKGROUND: Computed tomography during arterial portography (CTAP) under temporary balloon occlusion of the hepatic artery (BOHA-CTAP) was introduced to evaluate pseudolesions caused by portal venous impairments such as arterioportal shunt and tumor thrombus. METHODS: BOHA-CTAP was performed in seven patients with hepatocellular carcinoma and correlated with clinical outcomes. For patients with wedge-shaped defects suggestive of pseudolesions, BOHA-CTAP was obtained by a 5-F balloon occlusion catheter into the proper hepatic artery through the second 5-F introducer inserted into the common femoral artery a few centimeters below the first 5-F sheath for CTAP. RESULTS: Eight pseudolesions were determined clinically on follow-up CT, ultrasonography, or magnetic resonance imagings. On BOHA-CTAP, five of the eight pseudolesions were eliminated, and two were diminished in comparision with conventional CTAP. One wedge-shaped defect due to tumor thrombus in the portal vein did not show any change. CONCLUSION: BOHA-CTAP can reduce pseudolesions caused by portal venous impairments and enable the demarcation of the true tumors.

[Metallic stent placement for iliac artery occlusive disease].

Since 1991, we have performed stent placement for 35 iliac artery lesions in 31 patients. The etiologic diseases were atherosclerotic in 34 patients and traumatic dissection in one. The indications of placement were total occlusion in 3, late restenosis after angioplasty in 5, dissection in 5, and residual stenosis due to inadequate angioplasty in 21. We also performed direct stent placement for one traumatic dissection. The stents used were Wallstents in 10, Palmaz stents in 14, Strecker stents in 9, and Memotherm stents in 2 lesions. Follow-up was performed clinically or angiographically with measurement of the ankle/arm pressure index. Stent placement was successful in all cases, and relief or improvement of symptoms was achieved. The follow-up period ranged from 6-85 months (mean, 37.3 months). Late stent stenosis or occlusion occurred in 6 cases, among which 4 occluded lesions were successfully recanalized by thrombolytic therapy with angioplasty or second stent placement. In total, the primary patency rates were 88% and 77% at two and four years, respectively, while the secondary patency rates were 94% and 94%. In conclusion, metallic stent placement may offer extended application of intravascular treatment for iliac artery occlusive disease, and good long-term patency rates can be expected.

Long-term results of percutaneous transluminal angioplasty for hemodialysis shunt insufficiency

Purpose: The purpose of this study was to evaluate the long-term results of percutaneous transluminal angioplasty (PTA) for stenosis and/or occlusion of dialysis shunts. Methods: One hundred thirty-nine stenosed or thrombosed dialysis shunts (99 native fistulae, 37 grafts) in 122 patients were treated by PTA. In 39 cases, additional PTA for restenosis was performed. In total, 230 PTAs were performed (1-10 PTA/shunt). Results: The initial success rate was 86% in cases without occlusion. In contrast, the success rate in cases with occlusion was 53%, significantly worse than in the cases without occlusion. In cases in which initial success was obtained, primary cumulative patency rates at 3, 6, and 12 months were 87%, 60%, and 40%, respectively. With repeat PTA, secondary cumulative patency rates at 3, 6, 12, and 24 months were 96%, 83%, 63%, and 55%, respectively. Patency of native fistulae was better than patency of grafts. There was no significant relationship between the anatomical location of the stenoses and the patency rates. Conclusion: PTA is an effective treatment for shunt stenosis; although primary patency after PTA is not sufficient, repeated PTA increases patency.

[Contrast medium injection on CT during hepatic arteriography: comparison of two protocols].

To assess the optimum method of contrast medium injection on CT during hepatic arteriography (CTHA), we performed this procedure in 37 patients using two consecutive protocols (A and B) employing different concentrations of iodine (iohexol at 140 mgI/ml and 300-350 mgI/ml), flow rates (2 ml/sec and 1 ml/sec), and contrast medium volumes (60 ml and 30 ml). Mean parenchymal enhancement of the right lobe and left lateral segment were measured and compared. Enhancement varied significantly more with protocol B, especially in the left lateral segment. These results suggest that a low iodine concentration and high injection rate are suitable for CTHA, to avoid nonuniform parenchymal enhancement.

[Angiography of occlusive vascular disease].

Angiography is still "the gold standard" of diagnosis of arterial and venous disease. With improvement of equipment, materials and contrast media, angiography has become less invasive and increased its image quality. Because the resolution of digital subtraction angiography (DSA) has been improved and the size of image intensifier has become large enough, DSA is being substituted for conventional angiography. Rotational DSA and stepping DSA have made it possible to evaluate a vessel from multi-direction or the whole lower extremity with one injection of contrast media. Improvement of catheter, guide wire and contrast media has reduced complications and made angiography less invasive examination. Progress of angiography contributes to interventional radiology, which uses the technique of angiography for therapy.

[Interventional radiology for the peripheral vascular occlusive disease].

Recently interventional radiology (IVR) has been playing an important role as a treatment for the vascular occlusive disease. We describe the recent advances in the transcatheter techniques. Thrombolysis is widely used for the treatment of acute thrombotic occlusion. And balloon angioplasty (PTA) is still accepted as the gold standard for chronic arterial occlusive disease. Some other procedures, such as mechanical thrombectomy, atherectomy and metallic stent, are now available. More clinical experiences are necessary to improve the initial and long-term success rate of these techniques.

Small renal cell carcinoma: MRI with pathologic correlation.

The MRI features of small renal cell carcinomas (RCCs) were retrospectively reviewed and correlated with histology in 24 patients. MRI features on both T1- and T2-weighted images were classified into hypointensity, isointensity, and hyperintensity. Each tumor was pathologically classified into four types: alveolar, papillary, tubular, and cystic. These findings were correlated with MR signal intensities. Alveolar tumors showed hypointensity to isointensity on T1-weighted image and isointensity to hyperintensity on T2-weighted image. In contrast, all papillary tumors showed hypointensity on T2-weighted image. Four of six tumors with hypointensity on T2-weighted image were caused by hemosiderin deposition, hemorrhage, and necrosis. However, there were two papillary RCCs that showed hypointensity on T2-weighted image despite no hemosiderin deposition and no hemorrhage. We conclude that papillary RCC is associated with T2-hypointense appearance as well as hemosiderin deposition, hemorrhage, and necrosis.

Angiomyolipoma: imaging findings in lesions with minimal fat.

PURPOSE: To investigate a method of diagnosing angiomyolipoma that contains minimal fat. MATERIALS AND METHODS: In six cases of angiomyolipoma with minimal fat, the attenuation on contrast material-enhanced and unenhanced computed tomographic (CT) images, the echogenicity on sonograms, the signal intensity on T2-weighted magnetic resonance (MR) images, and the gross configuration of the lesion were retrospectively analyzed. In 100 cases of renal cell carcinoma, the same parameters were analyzed, and results were compared with those of angiomyolipoma. RESULTS: When compared with the surrounding renal parenchyma, all six angiomyolipomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms. Of the five angiomyolipomas examined with MR imaging, four were hypointense and one was isointense on T2-weighted images. All six angiomyolipomas protruded from the renal margin. None of the 100 renal cell carcinomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, or homogeneous isoechogenicity on sonograms. CONCLUSION: In the kidney, homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms are suggestive of angiomyolipoma that contains abundant muscle and minimal fat.

[Embolization for massive retroperitoneal hemorrhage from adrenal pheochromocytoma: a case report].

A 68-year-old woman was found crouching in the kitchen with severe upper abdominal pain. She entered a state of shock at our emergency clinic. Abdominal computed tomography (CT) scan demonstrated a 3 cm cystic mass dorsal to the pancreas tail accompanied with a hematoma. On angiography, a bleeding from the left middle adrenal artery was identified and embolized for hemostasis. An operation was performed 3.5 months after embolization. Preoperative evaluation showed the tumor to be endocrinologically inactive. Metoclopramide stimulation test was negative, too. Left adrenalectomy was performed uneventfully without intraoperative increase in blood pressure. However, histopathological diagnosis was pheochromocytoma. Transarterial embolization is an effective treatment for adrenal bleeding. In our case, however, embolization might have caused the tumor to be falsely "endocrinologically inactive".

[CT anatomy of the caudate lobe of the liver].

The anatomy of the portal vein branches in the caudate lobe of the liver was studied in 20 patients by double-phase CT arterial portography (DP-CTAP). DP-CTAP provided excellent images of the portal venous system in the first phase and the perfusion defects of intrahepatic tumors in the second phase. From DP-CTAP images of the first phase, a sufficient number of interpolated images were created for a smooth paging display. The ramifying structures of the portal system were traced on the monitor using the tracking ball. This method was found to be very effective and reliable for the anatomical assessment of the caudate lobe. The number and origins of the caudal portal branches were investigated in each case, and the caudate lobe of the liver could be divided into right and left segments.

[Atherectomy with over-the-wire type catheter for femoro-popliteal artery stenosis: initial and eight month follow-up results].

Percutaneous atherectomy using Atherotrack was performed in 5 patients with symptomatic femoro-popliteal artery stenosis. All patients were men and ages ranged from 37 to 70. Four lesions were atherosclerotic and 1 lesion was post-operative anastomotic stenosis following traumatic popliteal artery injury. There was no technical failure and all lesions were successfully dilated with no or minimal residual stenosis. API returned within normal limit and patients were symptom-free immediately after the procedure. We experienced no major complication related to this procedure. Excised specimen included thickened fibrous intima, atherosclerotic materials, calcification, internal elastic lamina and fibrous media. Follow-up DSA 5 months after procedure showed good patency in 4 cases, and they remained free from symptoms in this follow-up period. In those patients, lesions were generally short and eccentric, run-off was good, and only thickened intimal tissue was obtained. Those factors seem to promise long-term patency and to be good indications of atherectomy. Restenosis as well as recurrence of claudication, however, developed in one patient with DM, who had long, tight, complex stenosis and poor run-off. Considerable amount of medial tissue was found in this specimen. We suspect that those factors were associated with reduced long-term patency rates.

[Blood flow measurement of renal artery branches, in special reference to interlobular artery by color Doppler].

Blood flow measurement was performed in 58 kidneys of healthy persons. Detection rate, maximum flow velocity (Vmax), pulsatility index (PI) and resistive index (RI) were measured at main renal artery, segmental artery, interlobar artery and interlobular artery with 2 D-Doppler ultrasound machines. Detection rate was highest at interlobar artery. Vmax and PI tended to fall down with arterial branching. Interlobular artery was usually not visualized by color flow mapping, but sometimes well visualized using Acuson machines. Additional measurement of interlobar and interlobular arteries were performed in such 15 cases, and the result was essentially equal to the above mentioned study.

[CT angiography of the liver].

The diagnostic efficacy of CT arterial portography (CTAP) for the hepatic tumors has been established. We developed the double-phase incremental CTAP (DP-CTAP) using a fast CT scanner, by which the double-phase scanning of the whole liver was made during a single contrast administration. The DP-CTAP was performed in 9 cases of hepatic diseases, and was useful for the lesion detection and improvement of the visualization of the liver vasculatures. The maximum density projection angiogram of the portal and hepatic veins was easily made by DP-CTAP images, and useful for three dimensional understanding of the liver vasculatures and the detection of the vascular abnormalities.

[Percutaneous transluminal angioplasty for stenotic dialysis arterio-venous fistulas].

From December 1982 to January 1991, we performed fistulography on 40 patients who complained functional failure of arterio-venous dialysis fistula. And percutaneous transluminal angioplasty (PTA) was attempted on 15 patients (19 times) who revealed marked fistula stenosis. Initial successful rate was 78.9% and patency rate was 56.2% in the first 6 months. (75% in the first 6 months when angioplasty was initially successful). We describe the method of fistulography and PTA for stenotic dialysis fistulas, and evaluate the usefulness of PTA. And also we introduce our attempts for improving the initial successful rate and patency rate. In conclusion, when dialysis arterio-venous fistula is stenotic but not occlusive, PTA should be considered first before surgical treatment is done.