•
Diagnostic Radiology
Nonobstructive Circumcaval (Retrocaval) Ureter A Reportof 2 Cases1 James E. W. Crosse, M.D., Douglas W. Soderdahl, M.D., Steven K. Tepllck, M.D.,2 and Robert E. Clark, M.D.3 Two cases of circumcaval ureter without obstruction are described. The diagnosis of circumcaval ureter should be considered in the evaluation of a patient with medial deviation of the right ureter to the pedicles of L3 and L4, even in the absence of hydronephrosis. INDEX TERMS: Ureter, abnormalities. Ureter, displacement Radiology 116:69-71, July 1975
•
• Excretory urography revealed an arc-like right ureteral deviation medial to the pedicle of L4 without ureteral or renal obstruction (Fig. 2, A and B). A right retroperitoneal mass could not be excluded radiographically. The radiographic diagnosis of circumcaval ureter was entertained but thought to be unlikely due to lack of ureteral obstruction. Abdominal aortography, selective visceral arteriography, and lymphangiography were normal. Inferior vena cavography with a right ureteral catheter in place provided unequivocal evidence of a right circumcaval ureter (Fig. 2, C). No therapy was deemed necessary.
ureter, first reported by Hochstetter in 1893 (3), is a venous rather than a urinary anomaly in which the postcardinal venous system fails to atrophy but instead becomes the adult inferior vena cava (6). The name circumcaval ureter, rather than retrocaval or postcaval ureter, is preferred to describe this anomaly, because the right ureter may rarely pass posterior to the inferior vena cava yet reappear laterally without circumscribing it (2). Circumcaval ureter is considered to be a rare congenital anomaly. In 1971, Shown and Moore noted that approximately 150 cases had been reported and added 4 new cases (8). Despite the small number of reported cases, Nielsen found the frequency of circumcaval ureter to be 0.9 per 1,000 cases in a postmortem series (5). Perhaps a significant number of cases are not diagnosed radiographically because hydronephrosis is thought to be an invariable radiographic finding. To our knowledge, nonobstructive circumcaval ureter has not been described previously. We wish to report 2 such cases and review the radiographic differential diagnosis.
C
IRCUMCAVAL
DISCUSSION Radiologically, two patterns of circumcaval ureter can be deflned (2, 4). In the more common form (Type· 1), there is moderate or severe hydronephrosis and an "S" or "fish-hook" deformity of the ureter at the point of obstruction as well as extreme medial deviation of the middle segment. Narrowing occurs at the lateral border of the psoas muscle, so that compression by the inferior vena cava is thought not to be important in the production of obstruction (2). In Type 2, hydronephrosis is less marked, the ureter is less severely deviated, and the point of obstruction is located at the lateral wall of the inferior vena cava. Some intermediate cases of circumcaval ureter cannot readily be classified (Fig. 3). Medial deviation of the middle third of the right ureter to the level of the pedicles of L3 and L4 may be caused by retroperitoneal fibrosis, a retroperitoneal mass, or circumcaval ureter. Retroperitoneal fibrosis is only occasionally unilateral and rarely occurs without obstructive uropathy (1). A follow-up excretory urogram should demonstrate the onset of obstructive uropathy in the rare case where ureteral obstruction is not present initially. A retroperitoneal mass should cause renal displacement, and the ureteral deviation should be arc-like.
CASE REPORTS CASE I: A 39-year-old white man was found to be hypertensive (180/120 mm Hg) on routine physical examination. Excretory urography revealed medial deviation of the middle third of the right ureter without hydronephrosis, and a right retroperitoneal mass was suspected. The history, physical examination, and laboratory studies were unrevealing. Excretory urography and inferior vena cavography performed simultaneously demonstrated the right circumcaval ureter (Fig. 1). No treatment was required. CASE II: A 46-year-old white man presented with right flank pain which was episodic in nature and unrelated to fluid load. The history, physical examination, and laboratory studies were unremarkable.
1 From the Urology Service and the Department of Radiology, Tripier Army Medical Center, San Francisco, Calif. Accepted for publication in January 1975. 2 Current address: Boston University Medical School (S. K. T., Assistant Professor of Radiology), Boston, Mass. 02118. 3 Current address: University of California School of Medicine (R. E. C., Assistant Professor of Radiology), San Francisco, Calif. 94143. sjh
69
Fig. 1. CASE I. A. Excretory urogram, anteroposterior projection, with a catheter in the inferior vena cava. The right ureter courses medially to the pedicle of L3 and descends to L6. B. Right posterior oblique projection demonstrates the course of the right ureter posterior to the inferior vena cava with no evidence of obstruction. An arterial catheter is present in the right common iliac artery. C. Cross-table lateral view shows that the left ureter follows a normal course. The right ureter courses parallel and adjacent to the anterior margin of the vertebral body (arrows).
Fig. 2. CASE II. A. Excretory urogram obtained following aortography demonstrates medial deviation of the right ureter to the right pedicles of L3 to L5. No evidence of ureteral obstruction is noted. An arterial catheter is in place. B. Inferior vena cavogram in the anteroposterior projection shows residual contrast material in the lymph nodes from prior lymphangiography. The right ureteral catheter courses medially to the inferior vena cava from L3 to L5. C. Inferior vena cavogram in the right posterior oblique projection again demonstrates the right ureteral catheter coursing medially and posteriorly to the inferior vena cava and causing obstruction at the ureteropelvic junction.
70
71
NONOBSTRUCTIVE CIRCUMCAVAL (RETROCAVAL) URETER
Vol. 116
Diagnostic Radiology
Saldino and Palubinskas reported that 18 % of the normal patients they studied had ureters which were at or medial to the pedicles of L5 or S1, and almost all of the ureters in these patients were right-sided. Only a small portion were deviated at the level of L4 (7). Those patients with medial deviation at the L4 pedicle in Saldino's series may represent nbndiagnosed retrocaval ureters, which were found by Nielsen in his postmortem series (5).
If the above pathological entities still remain a consideration after initial evaluation by excretory urography, inferior vena cavography with a right ureteral catheter in place will provide unequivocal proof of nonobstructive circumcaval right ureter. We wish to caution against subjecting a patient to an extensive radiological work-up for a suspected right retroperitoneal mass when a nonobstructive circumcaval ureter may be the cause of the medially deviated right ureter. Robert E. Clark, M.D. Department of Radiology Veterans Administration Hospital 4150 Clement St. San Francisco, Calif. 94121
REFERENCES 1. Arger PH, Stolz JL, Miller WT: Retroperitoneal fibrosis: an analysis of the clinical spectrum and roentgenographic signs. Am J RoentgenoI119:812-821, Dec 1973 2. Bateson EM, Atkinson 0: Circumcaval ureter: a new classification. Clin Radiol 20: 173-177, Apr 1969 3. Hochstetter F: Beitrage zur Entwicklungsgeschichte des
TYPE I
Fig. 3.
A. B.
TYPE 1\
Type 1 circumcaval ureter. Type 2 circumcaval ureter.
Venensystems der Amnioten: II. Reptilien (Lacerla, Tropidonotus). Morphol Jahrb (Leipzig) 19:428-501, 1892-1893 4. Lindholm A, Lantto S, Svartholm F: Retrocaval ureter. Re.port of a case. Scand J Urol Nephrol 6:203-205, 1972 5. Nielsen PB: Retrocaval ureter. Report of a case. Acta Radiol 51:179-188, Mar 1959 6. Randall A, Campbell EW: Anomalous relationship of the right ureter to the vena cava. J UroI34:565-583, Dec 1935 7. Saldino RM, Palubinskas AJ: Medial placement of the ureter: a normal variant which may simulate retroperitoneal fibrosis. J Urol 107:582-585, Apr 1972 8. Shown TE, Moore CA: Retrocaval ureter: 4 cases. J Urol 105:497-501, Apr 1971
Diagnostic Radiology
Nonobstructive Circumcaval (Retrocaval) Ureter A Reportof 2 Cases1 James E. W. Crosse, M.D., Douglas W. Soderdahl, M.D., Steven K. Tepllck, M.D.,2 and Robert E. Clark, M.D.3 Two cases of circumcaval ureter without obstruction are described. The diagnosis of circumcaval ureter should be considered in the evaluation of a patient with medial deviation of the right ureter to the pedicles of L3 and L4, even in the absence of hydronephrosis. INDEX TERMS: Ureter, abnormalities. Ureter, displacement Radiology 116:69-71, July 1975
•
• Excretory urography revealed an arc-like right ureteral deviation medial to the pedicle of L4 without ureteral or renal obstruction (Fig. 2, A and B). A right retroperitoneal mass could not be excluded radiographically. The radiographic diagnosis of circumcaval ureter was entertained but thought to be unlikely due to lack of ureteral obstruction. Abdominal aortography, selective visceral arteriography, and lymphangiography were normal. Inferior vena cavography with a right ureteral catheter in place provided unequivocal evidence of a right circumcaval ureter (Fig. 2, C). No therapy was deemed necessary.
ureter, first reported by Hochstetter in 1893 (3), is a venous rather than a urinary anomaly in which the postcardinal venous system fails to atrophy but instead becomes the adult inferior vena cava (6). The name circumcaval ureter, rather than retrocaval or postcaval ureter, is preferred to describe this anomaly, because the right ureter may rarely pass posterior to the inferior vena cava yet reappear laterally without circumscribing it (2). Circumcaval ureter is considered to be a rare congenital anomaly. In 1971, Shown and Moore noted that approximately 150 cases had been reported and added 4 new cases (8). Despite the small number of reported cases, Nielsen found the frequency of circumcaval ureter to be 0.9 per 1,000 cases in a postmortem series (5). Perhaps a significant number of cases are not diagnosed radiographically because hydronephrosis is thought to be an invariable radiographic finding. To our knowledge, nonobstructive circumcaval ureter has not been described previously. We wish to report 2 such cases and review the radiographic differential diagnosis.
C
IRCUMCAVAL
DISCUSSION Radiologically, two patterns of circumcaval ureter can be deflned (2, 4). In the more common form (Type· 1), there is moderate or severe hydronephrosis and an "S" or "fish-hook" deformity of the ureter at the point of obstruction as well as extreme medial deviation of the middle segment. Narrowing occurs at the lateral border of the psoas muscle, so that compression by the inferior vena cava is thought not to be important in the production of obstruction (2). In Type 2, hydronephrosis is less marked, the ureter is less severely deviated, and the point of obstruction is located at the lateral wall of the inferior vena cava. Some intermediate cases of circumcaval ureter cannot readily be classified (Fig. 3). Medial deviation of the middle third of the right ureter to the level of the pedicles of L3 and L4 may be caused by retroperitoneal fibrosis, a retroperitoneal mass, or circumcaval ureter. Retroperitoneal fibrosis is only occasionally unilateral and rarely occurs without obstructive uropathy (1). A follow-up excretory urogram should demonstrate the onset of obstructive uropathy in the rare case where ureteral obstruction is not present initially. A retroperitoneal mass should cause renal displacement, and the ureteral deviation should be arc-like.
CASE REPORTS CASE I: A 39-year-old white man was found to be hypertensive (180/120 mm Hg) on routine physical examination. Excretory urography revealed medial deviation of the middle third of the right ureter without hydronephrosis, and a right retroperitoneal mass was suspected. The history, physical examination, and laboratory studies were unrevealing. Excretory urography and inferior vena cavography performed simultaneously demonstrated the right circumcaval ureter (Fig. 1). No treatment was required. CASE II: A 46-year-old white man presented with right flank pain which was episodic in nature and unrelated to fluid load. The history, physical examination, and laboratory studies were unremarkable.
1 From the Urology Service and the Department of Radiology, Tripier Army Medical Center, San Francisco, Calif. Accepted for publication in January 1975. 2 Current address: Boston University Medical School (S. K. T., Assistant Professor of Radiology), Boston, Mass. 02118. 3 Current address: University of California School of Medicine (R. E. C., Assistant Professor of Radiology), San Francisco, Calif. 94143. sjh
69
Fig. 1. CASE I. A. Excretory urogram, anteroposterior projection, with a catheter in the inferior vena cava. The right ureter courses medially to the pedicle of L3 and descends to L6. B. Right posterior oblique projection demonstrates the course of the right ureter posterior to the inferior vena cava with no evidence of obstruction. An arterial catheter is present in the right common iliac artery. C. Cross-table lateral view shows that the left ureter follows a normal course. The right ureter courses parallel and adjacent to the anterior margin of the vertebral body (arrows).
Fig. 2. CASE II. A. Excretory urogram obtained following aortography demonstrates medial deviation of the right ureter to the right pedicles of L3 to L5. No evidence of ureteral obstruction is noted. An arterial catheter is in place. B. Inferior vena cavogram in the anteroposterior projection shows residual contrast material in the lymph nodes from prior lymphangiography. The right ureteral catheter courses medially to the inferior vena cava from L3 to L5. C. Inferior vena cavogram in the right posterior oblique projection again demonstrates the right ureteral catheter coursing medially and posteriorly to the inferior vena cava and causing obstruction at the ureteropelvic junction.
70
71
NONOBSTRUCTIVE CIRCUMCAVAL (RETROCAVAL) URETER
Vol. 116
Diagnostic Radiology
Saldino and Palubinskas reported that 18 % of the normal patients they studied had ureters which were at or medial to the pedicles of L5 or S1, and almost all of the ureters in these patients were right-sided. Only a small portion were deviated at the level of L4 (7). Those patients with medial deviation at the L4 pedicle in Saldino's series may represent nbndiagnosed retrocaval ureters, which were found by Nielsen in his postmortem series (5).
If the above pathological entities still remain a consideration after initial evaluation by excretory urography, inferior vena cavography with a right ureteral catheter in place will provide unequivocal proof of nonobstructive circumcaval right ureter. We wish to caution against subjecting a patient to an extensive radiological work-up for a suspected right retroperitoneal mass when a nonobstructive circumcaval ureter may be the cause of the medially deviated right ureter. Robert E. Clark, M.D. Department of Radiology Veterans Administration Hospital 4150 Clement St. San Francisco, Calif. 94121
REFERENCES 1. Arger PH, Stolz JL, Miller WT: Retroperitoneal fibrosis: an analysis of the clinical spectrum and roentgenographic signs. Am J RoentgenoI119:812-821, Dec 1973 2. Bateson EM, Atkinson 0: Circumcaval ureter: a new classification. Clin Radiol 20: 173-177, Apr 1969 3. Hochstetter F: Beitrage zur Entwicklungsgeschichte des
TYPE I
Fig. 3.
A. B.
TYPE 1\
Type 1 circumcaval ureter. Type 2 circumcaval ureter.
Venensystems der Amnioten: II. Reptilien (Lacerla, Tropidonotus). Morphol Jahrb (Leipzig) 19:428-501, 1892-1893 4. Lindholm A, Lantto S, Svartholm F: Retrocaval ureter. Re.port of a case. Scand J Urol Nephrol 6:203-205, 1972 5. Nielsen PB: Retrocaval ureter. Report of a case. Acta Radiol 51:179-188, Mar 1959 6. Randall A, Campbell EW: Anomalous relationship of the right ureter to the vena cava. J UroI34:565-583, Dec 1935 7. Saldino RM, Palubinskas AJ: Medial placement of the ureter: a normal variant which may simulate retroperitoneal fibrosis. J Urol 107:582-585, Apr 1972 8. Shown TE, Moore CA: Retrocaval ureter: 4 cases. J Urol 105:497-501, Apr 1971
