Shigeo Takebayashi

TRANSARTERIAL EMBOLIZATION AND ABLATION OF RENAL ARTERIOVENOUS MALFORMATIONS: EFFICACY AND DAMAGES IN 30 PATIENTS WITH LONG-TERM FOLLOWUP

PURPOSEnWe evaluate the long-term efficacy and side effects of transarterial embolization and ablation for renal arteriovenous malformations.nnnMATERIALS AND METHODSnA total of 30 patients with cirsoid arteriovenous malformations causing massive hematuria underwent 34 procedures of embolization or ablation. We confirmed the ratios of occluded arteriovenous malformation areas on angiograms and those of infarcted areas on computerized tomography. All patients were followed for 4.1 to 15.0 years (mean 8.0 +/- 2.8) after the initial procedures.nnnRESULTSnHematuria ceased in all patients after the initial procedures, including partial embolization or ablation of the arteriovenous malformations in 8. Massive hematuria recurred in 4 patients, who had undergone absorbable gelatin sponge (2), embolization, combined alcohol and subselective absorbable gelatin sponge embolization (1) and polyvinyl alcohol particles embolization (1). In these 4 cases total ablation of the arteriovenous malformations with alcohol was successful. In 29 patients, including aforementioned 4, no hematuria recurred after 5 years following total or partial ablation with alcohol. Large nontarget embolization with reflux of subselectively infused absorbable gelatin sponge caused a nonfunctioning kidney in 1 patient. The remaining 33 procedures caused 6.3 to 48.0% (mean 15.7 +/- 6.9%) areas of renal infarction. Polyvinyl alcohol embolization caused pulmonary embolism and renin dependent hypertension.nnnCONCLUSIONSnPartial or total transarterial ablation of arteriovenous malformations with alcohol proved effective for long-term cessation of hematuria. However, this procedure as well as transarterial embolization has the potential risk of nontarget infarction.

c-erbb-2 gene amplification as a prognostic marker in human bladder cancer

OBJECTIVESnTo evaluate c-erbB-2 gene amplification and its prognostic significance in transitional cell carcinoma of the bladder.nnnMETHODSnAlterations in the gene copy number of c-erbB-2 were detected in 57 bladder tumor samples using a method based on the polymerase chain reaction.nnnRESULTSnEighteen tumors (32%) showed gene amplification of c-erbB-2, which correlated with tumor grade and stage. A strong association of c-erbB-2 amplification with patient survival was also found. The amplification resulted in a significantly poorer prognosis among the patients with high-grade and/or invasive tumors. Multivariate analysis revealed that c-erbB-2 amplification and tumor grade were independent prognostic factors.nnnCONCLUSIONSnOur data indicate a possible role of the c-erbB-2 gene in the development of aggressive behavior in bladder tumors. Moreover, the use of c-erbB-2 gene amplification, together with tumor grade and stage, could provide an accurate basis for determining the prognosis of bladder cancer.

Computerized tomographic ureteroscopy for diagnosing ureteral tumors.

PURPOSEnHelical computerized tomography (CT) image acquisition has led to the availability of improved data sets for CT endoscopic imaging that represent virtual endoscopy using CT. We assessed the usefulness of CT ureteroscopic imaging for diagnosing ureteral tumors.nnnMATERIALS AND METHODSnA total of 16 patients with ureteral stenosis underwent surface rendering CT ureteroscopy after the intravenous administration of contrast material and furosemide. To distinguish ureteral tumors from ureteral strictures 2 observers blinded to other patient history and evaluation data independently and prospectively evaluated CT ureteroscopy with reformatted CT ureterograms in these 16 patients. CT ureteroscopic images were then correlated with surgical and pathological findings, which served as the gold standard.nnnRESULTSnSurgical and pathological findings in the 16 patients revealed 16 ureteral tumors, including carcinoma in 10 (carcinoma in situ in 1, fibroepithelial polyps in 2 and hyperplastic polypoids in 4), inflammatory intrinsic stricture in 2 and extrinsic stricture in 4 caused by retroperitoneal fibrosis in 2 and lymph node metastasis in 2. CT ureteroscopy correctly detected all lesions except 1 carcinoma in situ, 1 polypoid carcinoma and 1 hyperplastic polypoid. The sensitivity and specificity of CT ureteroscopy for detecting ureteral tumors and carcinoma were 81% and 100%, and 80% and 75%, respectively, when tumors without stalks were considered carcinoma.nnnCONCLUSIONSnCT ureteroscopy is useful for visualizing the complex morphology of ureteral tumors and distinguishing tumor from ureteral stricture.

COMPUTERIZED TOMOGRAPHY NEPHROSCOPIC IMAGES OF RENAL PELVIC CARCINOMA

PURPOSEnComputerized tomography (CT) endoscopy is an interactive 3-dimensional image acquired by helical CT. We assess the usefulness of CT nephroscopy in the diagnosis of renal pelvic cancers.nnnMATERIALS AND METHODSnSurface rendering CT nephroscopy was performed after intravenous administration of contrast agent and furosemide in 32 patients with suspected renal pelvic carcinoma. Retrospective review revealed that 23 patients later underwent nephroureterectomy. Two observers blinded to the pathology results independently reviewed the CT nephroscopic and axial CT images of the 23 patients to localize pelvic tumors and to determine the extent of the disease. The CT nephroscopic and axial CT images were correlated with the pathological findings.nnnRESULTSnPathological examination revealed 4 polypoid, 6 pedunculated, 7 sessile, 1 sessile with ulceration and 6 infiltrating renal pelvic carcinomas in the 23 patients. CT nephroscopy revealed 22 carcinomas (92%) and CT demonstrated 20 (83%). CT nephroscopy was superior to axial CT in detecting 4 pedunculated and 3 infiltrating carcinomas but failed to detect 1 sessile carcinoma which completely replaced the upper portion of a double renal pelvis and 1 polypoid tumor associated with infiltrating carcinoma. The CT nephroscopic images correlated well with pathological findings.nnnCONCLUSIONSnCT nephroscopy is useful to visualize the complex morphology of renal pelvic carcinomas noninvasively and is superior to axial CT for the detection of infiltrating and pedunculated carcinomas.

MR angiography of renal vascular malformations

Objective We wanted to determine whether three-dimensional phase contrast (3DPC) MR angiography is clinically useful in the diagnosis of renal vascular malformations. Materials and Methods Three-dimensional PC MR angiography was performed in 22 patients with gross hematuria and in 8 healthy volunteers. Small flip angles and 60 cm/s velocity encoding best demonstrated the normal intra-renal arteries with arteriovenous differentiation in the eight healthy volunteers. In the 22 patients with gross hematuria, intraarterial digital subtraction angiography demonstrated cirsoid-type malformations in 6 patients, aneurysmaltype malformations in 3 patients, and normal vascular anatomy in 13 patients. Results Magnetic resonance angiography detected all three aneurysmaltype malformations and four of the cirsoid-type malformations. Small cirsoid-type malformations were not detected in two patients. The moderate or large malformations were demonstrated as dilated and tortuous feeding arteries and high intensity renal veins with high flow velocity. We found no correlation between signal intensity in the suprarenal inferior vena cava and the presence of arteriovenous shunts. There were no false-positive cases. Conclusion Sensitivity, specificity, and accuracy in this series were 78, 100, and 91%, respectively.

A Case of Vesical Varices as a Complication of Portal Hypertension and Manifested Gross Hematuria

We report a unique case of vesical varices in a patient who presented with an episode of serious gross hematuria. He also had cirrhosis of the liver and portal hypertension, and had undergone transection of the esophagus 10 years ago. A hemangiomatous mass was discovered on cystoscopic examination, and sonographic examination, computerized tomography and abdominal angiography revealed vesical varices. The genesis of vesical varices and possible treatment in this case are discussed.

MRI of the TMJ Disc with Intravenous Administration of Gadopentetate Dimeglumine

PURPOSEnThe purpose of this study was to ascertain whether MR imaging with intravenous administration of gadopenetate dimeglumine (Gd-DTPA) is useful in the demonstration of the temporomandibular joint (TMJ) disc.nnnMETHODnSagittal T1-weighted MR images of 50 TMJs (25 patients) were obtained using a 0.5-T system both before and after intravenous injection of Gd-DTPA. The authors depicted the TMJ in which intravenous injection of Gd-DTPA improved visulization of the disc.nnnRESULTSnIntravenous injection of Gd-DTPA increased intensity in the retrodiscal space, the pterygoid venous plexus, as well as joint effusion by diffused Gd-DTPA. The technique improved visualization of 10 (50%) of 20 normal discs and 20 (67%) of 30 anterior disc displacements in closed-mouth position, and also 23 (74%) of 31 normal discs and 12 (63%) of 19 anterior disc displacements in open-mouth position. There were 12 TMJs (24% of the 50 TMJs) in which equivocal findings became highly diagnostic. The incidence in marked contrast effect was higher in TMJs with severe internal derangement than in those with normal or mild internal derangement (p < 0.005).nnnCONCLUSIONnUsing a 0.5-T MR imager, T1-weighted imaging with intravenous injection of Gd-DTPA showed more anatomic details than imaging without the contrast agent.

Sonographic evaluation of kidneys undergoing dialysis

Sonograms in 205 patients undergoing dialysis were obtained to evaluate renal features according to duration of treatment. Both length and parenchymal thickness had gradually decreased in kidneys treated for less than 3 years. After the 3rd year of treatment, an apparent increase in the incidence of cysts was seen. Forty-three cases of acquired cystic disease, including 1 case with renal cell carcinoma, were detected. All kidneys had increased cortical echogenicity, with prominence first occurring after 7 years of dialysis. In patients undergoing dialysis for less than 3 years, those with diabetic nephropathy showed fewer changes from normal appearances than patients undergoing dialysis for treatment of glomerulonephritis.

A Case of Vesical Paraganglioma Behind the Symphysis Pubis

We report on a 15-year-old boy with a vesical paraganglioma behind the symphysis pubis. Magnetic resonance imaging and transurethral intravesical ultrasonography were helpful in the preoperative localization of the lesion.

Diagnosis of the Nutcracker Syndrome With Color Doppler Sonography: Correlation With Flow Patterns on Retrograde Left Renal Venography

OBJECTIVEnOur objective was to confirm flow patterns of the left renal vein and assess the usefulness of color Doppler sonography in the diagnosis of the renal vein entrapment, or nutcracker, syndrome.nnnSUBJECTS AND METHODSnForty-four patients with hematuria of unknown origin underwent color Doppler sonography, renal arteriography, retrograde left renal venography, and renocaval pressure measurement. The flow patterns were classified according to the presence or absence of distended left renal veins on sonograms and collateral veins on retrograde venograms. The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were assessed by analyzing pressure gradients in combination with the venograms, which were used as the gold standard.nnnRESULTSnTwenty-one nondistended left renal veins were seen, including 19 (43%) without collateral veins or hypertension and two (5%) with collateral veins but without hypertension (long-term nutcracker syndrome). The 23 distended left renal veins included seven without collateral veins or hypertension and one with hypertension but without collateral veins (early nutcracker syndrome). The remaining 15 distended left renal veins with collateral veins included 11 (25%) with borderline hypertension (partially compensatory status of the syndrome) and four (9%) with hypertension (noncompensatory status of the syndrome). The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were 78% and 100%, respectively, when color flow in collateral veins was included in the diagnostic criteria.nnnCONCLUSIONnThe nutcracker syndrome can exist in either nondistended or distended left renal veins. However, normal flow also can exist in distended left renal veins. The ability of color Doppler sonography to reveal color flow in collateral veins is useful for the noninvasive diagnosis of the nutcracker syndrome.