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Transcaval Ureter: Multidetector Computed Tomography Demonstration
Images in Clinical Urology Transcaval Ureter: Multidetector Computed Tomography Demonstration Carmelo Sofia, Sergio Racchiusa, Carlo Magno, Antonino Inferrera, Rocco Donato, Giuseppe Mucciardi, Silvio Mazziotti, and Giorgio Ascenti Transcaval ureter is a rare congenital anomaly characterized by an inferior cava vein duplication producing a vascular ring around the right ureter, usually determining hydroureteronephrosis. The knowledge of this vascular anomaly on imaging examinations permits to avoid erroneous diagnosis of retroperitoneal masses or adenopathy and preoperatively advise the surgeon of potential sources of complications. We describe a case of transcaval ureter studied with multidetector computed tomography. To our knowledge, this is the first case in which computed tomography multiplanar and volume-rendering reconstructions show this rare anomaly. UROLOGY 86: e3ee4, 2015. 2015 Elsevier Inc.
Figure 1. Axial computed tomography nephrographic phase image (A) shows the ureter as a hypodense teardrop-shaped image posterior to 2 enhanced round-shaped structure in the location of normal cava vein. Note the normal ureter on the left side (red arrow). Coronal CT nephrographic phase image (B) better shows the cava vein duplication in its full craniocaudal extension.
A
46-year-old man with right flank underwent a computed tomography (CT) examination with a multislice scanner. No urinary stones or external compression on the ureter were present at lowdose unenhanced scan. Contrast-enhanced CT study was performed during nephrographic and excretory phases. Images were analyzed with multiplanar (Fig. 1A,B),
Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico “G. Martino”, University of Messina, Messina, Italy; and the Unit of Urology, Department of Human Pathology, Policlinico “G. Martino”, University of Messina, Messina, Italy Address correspondence to: Carlo Magno, M.D., Unit of Urology, Department of Human pathology, Policlinico “G. Martino”, University of Messina, Via Consolare Valeria 1, Messina, Italy 98126. E-mail: [email protected] Submitted: January 29, 2015, accepted (with revisions): March 31, 2015
ª 2015 Elsevier Inc. All Rights Reserved
maximum-intensity-projection (Fig. 2A) and volumerendering (Fig. 2B) reconstructions. Multidetector CT showed a duplication of the postrenal segment of the inferior cava vein, forming a vascular ring around the right ureter causing hydronephrosis (Figs. 1, 2).
COMMENT The transcaval ureter is determined by a periureteric venous ring because of the persistence of right posterior cardinal and supracardinal right veins in postrenal position, giving origin to an inferior cava vein ringeshaped duplication with the ureter passing through it. This is an incidental finding on imaging or on cadaver dissections, and hydroureteronephrosis represents the most common clinical consequence.1-6 http://dx.doi.org/10.1016/j.urology.2015.03.029 0090-4295/15
e3
Figure 2. Coronal maximum-intensity projection (MIP) (A) and volume rendering technique (VRT) (B) reconstructions from excretory phase data display, and at the same time, the cava vein “ring” and the right ureter passing through it. Despite the MIP images being quite similar to conventional urograms, the entire anatomy of the right urinary tree with the dilated pelvicalyceal system (asterisk), proximal third of the right ureter (star), and the transcaval ureter (arrow) are well demonstrated with VRT in an only image, improving the speed of findings interpretation.
This anomaly must be identified to avoid surgical complications during retroperitoneal surgery.7-9 Surgical treatment of the transcaval ureter should be reserved to patients with a risk of renal function impairment or to those who are highly symptomatic.10
CONCLUSION Multidetector CT is the best noninvasive imaging technique for demonstrating transcaval ureter and cava vein duplication underlying this entity. Multiplanar and 3-dimensional reconstructions improve the speed of recognition of the findings and interpretation by the urologist surgeon. References 1. Lepage JR, Baldwin GN. Obstructive periureteric venous ring. Radiology. 1972;104:313-315. 2. Carrion H, Gatewood J, Politano V, et al. Retrocaval ureter: report of 8 cases and the surgical management. J Urol. 1979;121:514-517.
e4
3. Dharman K. Transcaval ureter. J Urol. 1980;123:575-576. 4. Rosen MP, Walker TG, Brennan JF, et al. Transcaval ureter with hydronephrosis: radiologic demonstration. AJR Am J Roentgenol. 1989;152:793-794. 5. Talner LB, Reilly PH, Wasserman NF. Specific causes of obstruction. In: Pollack HM, McClennan BL, eds. Clinical Urography. 2nd ed. Philadelphia, Pa: Saunders; 2000:1967-2136. 6. Totti Cavazzola L, Groisman R, Fernando de Oliveira V. Transcaval ureter: case report and a review of the literature. Eur J Anat. 2005;9: 59-62. 7. Tore HG, Tatar I, Celik HH, et al. Two cases of inferior vena cava duplication with their CT findings and a review of the literature. Folia Morphol (Warsz). 2005;64:55-58. 8. Babaian RJ, Johnson DE. Major venous anomalies complicating retroperitoneal surgery. South Med J. 1979;72:1254-1258. 9. Shaw MB, Cutress M, Papavassiliou V, et al. Duplicated inferior vena cava and crossed renal ectopia with abdominal aortic aneurysm: preoperative anatomic studies facilitate surgery. Clin Anat. 2003;16:355-357. 10. Gazaigne J, Alkhouja AS, Sebe P, Mozziconacci JG. Transcaval ureter. Prog Urol. 2002;12:486-489.
UROLOGY 86 (1), 2015
Figure 1. Axial computed tomography nephrographic phase image (A) shows the ureter as a hypodense teardrop-shaped image posterior to 2 enhanced round-shaped structure in the location of normal cava vein. Note the normal ureter on the left side (red arrow). Coronal CT nephrographic phase image (B) better shows the cava vein duplication in its full craniocaudal extension.
A
46-year-old man with right flank underwent a computed tomography (CT) examination with a multislice scanner. No urinary stones or external compression on the ureter were present at lowdose unenhanced scan. Contrast-enhanced CT study was performed during nephrographic and excretory phases. Images were analyzed with multiplanar (Fig. 1A,B),
Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico “G. Martino”, University of Messina, Messina, Italy; and the Unit of Urology, Department of Human Pathology, Policlinico “G. Martino”, University of Messina, Messina, Italy Address correspondence to: Carlo Magno, M.D., Unit of Urology, Department of Human pathology, Policlinico “G. Martino”, University of Messina, Via Consolare Valeria 1, Messina, Italy 98126. E-mail: [email protected] Submitted: January 29, 2015, accepted (with revisions): March 31, 2015
ª 2015 Elsevier Inc. All Rights Reserved
maximum-intensity-projection (Fig. 2A) and volumerendering (Fig. 2B) reconstructions. Multidetector CT showed a duplication of the postrenal segment of the inferior cava vein, forming a vascular ring around the right ureter causing hydronephrosis (Figs. 1, 2).
COMMENT The transcaval ureter is determined by a periureteric venous ring because of the persistence of right posterior cardinal and supracardinal right veins in postrenal position, giving origin to an inferior cava vein ringeshaped duplication with the ureter passing through it. This is an incidental finding on imaging or on cadaver dissections, and hydroureteronephrosis represents the most common clinical consequence.1-6 http://dx.doi.org/10.1016/j.urology.2015.03.029 0090-4295/15
e3
Figure 2. Coronal maximum-intensity projection (MIP) (A) and volume rendering technique (VRT) (B) reconstructions from excretory phase data display, and at the same time, the cava vein “ring” and the right ureter passing through it. Despite the MIP images being quite similar to conventional urograms, the entire anatomy of the right urinary tree with the dilated pelvicalyceal system (asterisk), proximal third of the right ureter (star), and the transcaval ureter (arrow) are well demonstrated with VRT in an only image, improving the speed of findings interpretation.
This anomaly must be identified to avoid surgical complications during retroperitoneal surgery.7-9 Surgical treatment of the transcaval ureter should be reserved to patients with a risk of renal function impairment or to those who are highly symptomatic.10
CONCLUSION Multidetector CT is the best noninvasive imaging technique for demonstrating transcaval ureter and cava vein duplication underlying this entity. Multiplanar and 3-dimensional reconstructions improve the speed of recognition of the findings and interpretation by the urologist surgeon. References 1. Lepage JR, Baldwin GN. Obstructive periureteric venous ring. Radiology. 1972;104:313-315. 2. Carrion H, Gatewood J, Politano V, et al. Retrocaval ureter: report of 8 cases and the surgical management. J Urol. 1979;121:514-517.
e4
3. Dharman K. Transcaval ureter. J Urol. 1980;123:575-576. 4. Rosen MP, Walker TG, Brennan JF, et al. Transcaval ureter with hydronephrosis: radiologic demonstration. AJR Am J Roentgenol. 1989;152:793-794. 5. Talner LB, Reilly PH, Wasserman NF. Specific causes of obstruction. In: Pollack HM, McClennan BL, eds. Clinical Urography. 2nd ed. Philadelphia, Pa: Saunders; 2000:1967-2136. 6. Totti Cavazzola L, Groisman R, Fernando de Oliveira V. Transcaval ureter: case report and a review of the literature. Eur J Anat. 2005;9: 59-62. 7. Tore HG, Tatar I, Celik HH, et al. Two cases of inferior vena cava duplication with their CT findings and a review of the literature. Folia Morphol (Warsz). 2005;64:55-58. 8. Babaian RJ, Johnson DE. Major venous anomalies complicating retroperitoneal surgery. South Med J. 1979;72:1254-1258. 9. Shaw MB, Cutress M, Papavassiliou V, et al. Duplicated inferior vena cava and crossed renal ectopia with abdominal aortic aneurysm: preoperative anatomic studies facilitate surgery. Clin Anat. 2003;16:355-357. 10. Gazaigne J, Alkhouja AS, Sebe P, Mozziconacci JG. Transcaval ureter. Prog Urol. 2002;12:486-489.
UROLOGY 86 (1), 2015