Case Report Gynecol Obstet Invest 1992;34:57-60
Hideoki Fukuokaa Noriko Fukushimab Kenji Uekanec Makoto Higurashia
Retrocaval Ureter with Recurrent Pyelonephritis
Department of Maternal and Child Health, School of Health Sciences, Faculty of Medicine, University of Tokyo, and Divisions of Clinical Pathology and Urology, Fraternity Memorial Hospital, Tokyo. Japan
Abstract A case of retrocaval ureter with recurrent pyelonephritis is presented with dis cussion of these clinical entities. An excretory urogram and retrograde urete rogram disclosed pronounced hydronephrosis as well as a dilated proximal part and reversed J-shaped appearance of the right ureter. The compressed retrocaval portion of the ureter was resected and an end-to-end anastomosis was performed anterior to the vena cava. Due to the progressive kidney dam age leading to severe hydronephrosis, a rapid radiological diagnosis should be made to replace the retropositioned ureter.
Introduction Retrocaval ureter, first reported by Hochstetter [ 1], is a rare congenital venous rather than urinary anomaly, in which the postcardinal venous system fails to atrophy but instead becomes the adult inferior vena cava [2], thereby leading to varying degrees of ureteral compression. The incidence rate is higher in males than females [3], and pregnancy had been reported to exacerbate ureteral com pression [4], This compression can result in gradual devel opment of hydronephrosis and hvdroureter, and some times leads to pyelonephritis [3], In cases of hydronephro sis, early diagnosis and surgical repositioning is important in order to salvage the remaining renal function before extreme renal deterioration occurs. Diagnosis is only pos sible using radiological examinations [4-8], thus, patients having symptoms of ureteral compression, recurrent py elonephritis, or hematuria should be promptly evaluated using radiological renoureteral examinations. Since ob stetricians occasionally treat patients with pyelonephritis,
Received: October 17.1991 Accepted: November 29. 1991
although rarely perform office radiological examinations, an informative case of type 1 retrocaval ureter with recur rent pyelonephritis is reported.
Case Report A 31-year-old female (gravida 4, para 3). having previously suf fered twice from pyelonephritis since the age of 27. was physically examined and found to suffer from severe right-flank and costoverte bral angle tenderness associated with remittent fever (39.1 °C). A simple episode of gross, terminal painless hematuria had preceded the pain. Urinalysis revealed numerous white blood cells and bacte ria, and a urine culture disclosed Escherichia coli. Diagnosis was right pyelonephritis, and the patient was started on parenteral cephalosporin. After a 5-day treatment with antibiotics which even tually led to recovery, and excretory urogram and a right retrograde ureterogram were performed. The excretory' urogram showed pronounced hydronephrosis as well as dilatation of the proximal part of the ureter, which had a reversed J-shapcd appearance on the right side. The left kidney was of normal size and showed good excretion of the contrast medium
Hideoki Fukuoka 7-3-1. Hongo Bunkyo-ku. Tokyo 113 (Japan)
© 1992 S. Karger AG. Basel 0378-7346/92/0341-0057 $2.75/0
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
Keywords Retrocaval ureter Recurrent pyelonephritis Ureter displacement Circumcaval ureter Ureter abnormalities
2
1
Fig. 1. Excretory renogram showing pro nounced right hydronephrosis as well as dila tation of the proximal part of the ureter which has a reversed J-shaped appearance on the right side. The left kidney is of normal size. Fig. 2. Retrograde ureteropyelogram showing the elongated ‘S’ shape of the right ureter and the flow obstruction point, with the retrocaval segment lying at the level of Li to L 4 .
(fig. 1). The retrograde ureterogram showed a tortuous ureter having an elongated ‘S' shape, beginningjust above the pelvic brim and end ing below the renal pelvis (fig. 2). A phenolsulphonphthalein (PSP) excretion test was taken to measure the renal secretory' function and subsequently disclosed delayed excretion, i.e.. an excretion of 47.6% in 60 min and 61.5% in 120 min. An end-to-end anastomosis ante rior to the vena cava was performed in addition to resection of the compressed portion of the retrocaval ureter. The splinting catheter was left indwelling. Twenty days after the operation, an excretory' ureterogram disclosed slight diminution of the hydronephrosis and hydroureter. Microscopic examination of the dissected, spatulated ureter (fig. 3) showed that there was nonspecific inflammation, an infiltration of many small round cells into the lamina propria, and no pathological changes in either the superficial or deep epithelial layers. Although the severe hydronephrosis and delayed excretion of PSP were evident, the compressed ureteral cavity was only slightly, narrowed, and a high degree of inflammation was not present, being located only in the lamina propria.
Fig. 3. Microscopic examination of the dissected, spatulated ure ter.
Conclusions
58
asymptomatic as well. In addition, the fact that the inci dence rate is three to four times higher in males than in females [3, 5, 11 ] makes this rare disorder of special inter est in the field of obstetrics and gynecology. The retrocaval position of the ureter to the inferior caval vein is the result of an abnormal development of the fetal abdominal venous channels [4. 9], Normally, the infrarenal part of the inferior vena cava originates from the right supracardinal vein which runs dorsally to the ureter, thus allowing the ureter to lie lateral to the inferior
Fukuoka/Fukushima/Uekane/Higurashi
Retrocaval Ureter
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
The occurrence frequency of inferior caval vein anom alies is not exactly known, although it is believed that they occur in 2-3% of the population [9], On the other hand, retrocaval ureter with clinical symptoms is significantly rare, i.e., incidence of less than 0.1 % of the population [9], Postmortem series, however, have shown an incidence of approximately 9 per 1,000 cases [5, 10]; thus, it appears that a significant number of undetected asymptomatic cases occur. It should be noted that children are seldom diagnosed [3], and the cases which have been are probably
mended [3], On the other hand, symptomatic patients having flow obstruction should undergo surgery to release the ureteral obstruction and restore normal renal func tion. This is normally performed by resecting either the upper ureter, as in the present case, or the renal pelvis, freeing it from its retrocaval position, followed by restor ing the continuity of the ureter in front of the inferior caval vein. With the exception of a few cases involving stricture formation at the site of anastomosis, calculus formation, and persistent infection, satisfactory results have generally been obtained using these surgical proce dures. Progressive damage has been reported to occur later in life with surgical difficulties and poor renoureteric recovery being encountered [3]. Five types of anomalies concerning the anatomic rela tions between the ureter and the inferior caval vein were originally reported [5, 15]. However. Bateson and Atkin son [14], Crosse et al. [2], and Kenawi and Williams [3] introduced a new radiographic classification for retro caval ureter using two category types. In the most com mon of the two categories, i.e., type 1 retrocaval ureter, severe or moderate hydronephrosis and marked medial deviation of the ureter with an S- or fish-hook-shaped deformity occurs. The flow obstruction appears at the edge of the iliopsoas muscle, at which point the ureter deviates cephalad before passing behind the vena cava. Radiological examinations show our case to be a type 1 retrocaval ureter. As to the urinary flow obstruction mechanism in this type, Bateson and Atkinson [14] recently found that compression by the inferior vena cava is not an important factor in producing the obstruction since narrowing occurs at the lateral border of the psoas muscle where the ureter turns upwards. In our patient, microscopic observation of the retropositioned ureter in dicated nonspecific inflammation and a noncompressed ureteral cavity (fig. 3), as well as showing the narrowest part of the ureter to be located at the lateral border of the psoas (fig. 1, 2). These results therefore support the find ing of Bateson and Atkinson [14]. In contrast, the type 2 retrocaval ureter shows a lesser degree or absence of hydronephrosis and slight medial deviation of the ureter, having a sickle-shaped curve that runs its length behind the cava. The ureter is less severely deviated, and the obstruction point is located at the lat eral wall of the inferior vena cava.
59
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
vena cava. In this particular anomaly, the more ventral infrarcnal subcardinal vein persists, thereby obliging the more dorsally placed ureter to pass behind and around it as the developing metanephros ascends from the pelvis to its final lumbar position. Patients with retrocaval ureter commonly suffer from flank pain, occasional hematuria, or urinal infection [3]. In cases of recurrent pyelonephritis, as in our case, retro caval ureter should be suspected. The formation of renal stones may also occur [3, 12]. Due to the gradual develop ment of associated hydronephrosis, patients most often develop complications during their thirties and forties [3, 5]. With regard to pregnancy, the patient delivered her first baby at 27 years, and 6 months later, while 8 weeks pregnant with her second baby, the first incidence of pyelonephritis occurred, although the baby was delivered without any further complications. At 30 years, she deliv ered her third baby without any complications. Two more instances occurred at 31 years (September and October), therefore the patient’s history does not support the find ing that pregnancy inevitably exacerbates the compres sion of the ureter to induce pyelonephritis [4], Excretory radiographs show the dilated proximal part of the ureter to have a reversed J-shaped appearance as it passes from the pelvis under the vena cava at the third or fourth lumbar vertebra (fig. 1) [6 , 7], Varying degrees of pronounced hydronephrosis are also noted proximal to the flow-obstructing compression area. In contrast, an excretory urography often fails to visualize the portion of the ureter beyond the J-shaped hook [3], Medial deviation of the middle third of the right ureter to the level of the pedicles of L 3 and L4 may be caused by retroperitoneal fibrosis, a retroperitoneal mass, or retrocaval ureter [8], Thus, as a further diagnostic procedure, retrograde pyelo graphy is important and sufficient, and will disclose the typically seen ‘S' image, i.e., permanent proximity of the ureter to the lower vertebral column. Additionally, cavography performed simultaneously with an indwelling catheter in the ureter is able to show the anatomical rela tions between the ureter and the inferior caval vein [2, 13], The standard treatment for retrocaval ureter is resec tion of the retrocaval ureter section and an end-to-end anastomosis anterior to the vena cava [6]. Occasionally, excision of the redundant ureter is necessary to prevent kinking and continued obstruction [3, 14], The kidney is saved, unless it has been severely damaged by flow obstruction and/or infection. In patients without symp toms, having either normal flow or a slight obstruction which is not increasing, periodic observation is recom
1 Hochstettcr F: Beiträge zur Entwicklungsge schichte des Venensystems der Amnioten. MorpholJahrb 1893:20:543-561. 2 Crosse JEW. Sodcrdahl DW, Teplick SK. Clark RE: Nonobstructive circumcaval (retrocaval) ureter - A case report o f 2 cases. Radiology 1975:116:69-71. 3 Kenawi MM. Williams Di: Circumcaval ure ter: A report of four cases in children with a review of the literature and a new classifica tion. Br J Urol 1976;48:183-192. 4 Huntington GS, McClure CFW: The develop ment of veins in the domestic cat (Felix domestica) with special reference. I) to the shape taken by the supracardinal veins in the devel opment of the postcava and azygos veins and to the interpretation of the variant conditions of the postcava and its tributaries, as found in the adult. Anat Ree 1920:20:1-21.
60
5 Nielsen BP: Retrocaval ureter: Report of a case. Acta Radiol 1959:51:179-188. 6 Brito RR. Zulian RZ, Albuquerque J, Borges JB: Retrocaval ureter. Br J Urol 1973:45:144— 152. 7 Eidelman A. Yural E. Simon D. Sibi Y: Retro caval ureter. Eur Urol 1978:4:279-281. 8 Anger PH, Stolz JL. Miller WT: Retroperito neal fibrosis: An analysis of the clinical spec trum and roentgenographic signs. Am J Roent genol 1973;119:812-821. 9 Chuang VP. Mena CE. Hoskins PA: Congeni tal anomalies of the inferior vena cava. Review of embryogenesis and presentation of a simpli fied classification. Br J Radiol 1974:47:206213. 10 Heslin JE. Mamonas C: Retrocaval ureter. Re port of four cases and review of literature. J Urol 1951:65:212-222.
11 Koinuma N: A clinical study of retrocaval ure ter. Nishinihon J Urol 1980:4523:767-769. 12 Ekstroem T. Nilsson AE: Retrocaval ureter. Two roentgenographically diagnosed and sur gically corrected cases. Acta Chir Scand 1959: 1 18:53-59. 13 Hellsten S, Grabe M, Nylander G: Retrocaval ureter. Acta Chir Scand 1980:146:225-228. 14 Bateson EM, Atkinson D: Circumcaval ureter: A new classification. Clin Radiol 1969:20:173177. 15 Bohn CSL: Retrocaval ureter. Nord Med 1956: 55:641-644.
Fukuoka/Fukushima/Uekane/Higurashi
Retrocaval Ureter
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
References
Hideoki Fukuokaa Noriko Fukushimab Kenji Uekanec Makoto Higurashia
Retrocaval Ureter with Recurrent Pyelonephritis
Department of Maternal and Child Health, School of Health Sciences, Faculty of Medicine, University of Tokyo, and Divisions of Clinical Pathology and Urology, Fraternity Memorial Hospital, Tokyo. Japan
Abstract A case of retrocaval ureter with recurrent pyelonephritis is presented with dis cussion of these clinical entities. An excretory urogram and retrograde urete rogram disclosed pronounced hydronephrosis as well as a dilated proximal part and reversed J-shaped appearance of the right ureter. The compressed retrocaval portion of the ureter was resected and an end-to-end anastomosis was performed anterior to the vena cava. Due to the progressive kidney dam age leading to severe hydronephrosis, a rapid radiological diagnosis should be made to replace the retropositioned ureter.
Introduction Retrocaval ureter, first reported by Hochstetter [ 1], is a rare congenital venous rather than urinary anomaly, in which the postcardinal venous system fails to atrophy but instead becomes the adult inferior vena cava [2], thereby leading to varying degrees of ureteral compression. The incidence rate is higher in males than females [3], and pregnancy had been reported to exacerbate ureteral com pression [4], This compression can result in gradual devel opment of hydronephrosis and hvdroureter, and some times leads to pyelonephritis [3], In cases of hydronephro sis, early diagnosis and surgical repositioning is important in order to salvage the remaining renal function before extreme renal deterioration occurs. Diagnosis is only pos sible using radiological examinations [4-8], thus, patients having symptoms of ureteral compression, recurrent py elonephritis, or hematuria should be promptly evaluated using radiological renoureteral examinations. Since ob stetricians occasionally treat patients with pyelonephritis,
Received: October 17.1991 Accepted: November 29. 1991
although rarely perform office radiological examinations, an informative case of type 1 retrocaval ureter with recur rent pyelonephritis is reported.
Case Report A 31-year-old female (gravida 4, para 3). having previously suf fered twice from pyelonephritis since the age of 27. was physically examined and found to suffer from severe right-flank and costoverte bral angle tenderness associated with remittent fever (39.1 °C). A simple episode of gross, terminal painless hematuria had preceded the pain. Urinalysis revealed numerous white blood cells and bacte ria, and a urine culture disclosed Escherichia coli. Diagnosis was right pyelonephritis, and the patient was started on parenteral cephalosporin. After a 5-day treatment with antibiotics which even tually led to recovery, and excretory urogram and a right retrograde ureterogram were performed. The excretory' urogram showed pronounced hydronephrosis as well as dilatation of the proximal part of the ureter, which had a reversed J-shapcd appearance on the right side. The left kidney was of normal size and showed good excretion of the contrast medium
Hideoki Fukuoka 7-3-1. Hongo Bunkyo-ku. Tokyo 113 (Japan)
© 1992 S. Karger AG. Basel 0378-7346/92/0341-0057 $2.75/0
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
Keywords Retrocaval ureter Recurrent pyelonephritis Ureter displacement Circumcaval ureter Ureter abnormalities
2
1
Fig. 1. Excretory renogram showing pro nounced right hydronephrosis as well as dila tation of the proximal part of the ureter which has a reversed J-shaped appearance on the right side. The left kidney is of normal size. Fig. 2. Retrograde ureteropyelogram showing the elongated ‘S’ shape of the right ureter and the flow obstruction point, with the retrocaval segment lying at the level of Li to L 4 .
(fig. 1). The retrograde ureterogram showed a tortuous ureter having an elongated ‘S' shape, beginningjust above the pelvic brim and end ing below the renal pelvis (fig. 2). A phenolsulphonphthalein (PSP) excretion test was taken to measure the renal secretory' function and subsequently disclosed delayed excretion, i.e.. an excretion of 47.6% in 60 min and 61.5% in 120 min. An end-to-end anastomosis ante rior to the vena cava was performed in addition to resection of the compressed portion of the retrocaval ureter. The splinting catheter was left indwelling. Twenty days after the operation, an excretory' ureterogram disclosed slight diminution of the hydronephrosis and hydroureter. Microscopic examination of the dissected, spatulated ureter (fig. 3) showed that there was nonspecific inflammation, an infiltration of many small round cells into the lamina propria, and no pathological changes in either the superficial or deep epithelial layers. Although the severe hydronephrosis and delayed excretion of PSP were evident, the compressed ureteral cavity was only slightly, narrowed, and a high degree of inflammation was not present, being located only in the lamina propria.
Fig. 3. Microscopic examination of the dissected, spatulated ure ter.
Conclusions
58
asymptomatic as well. In addition, the fact that the inci dence rate is three to four times higher in males than in females [3, 5, 11 ] makes this rare disorder of special inter est in the field of obstetrics and gynecology. The retrocaval position of the ureter to the inferior caval vein is the result of an abnormal development of the fetal abdominal venous channels [4. 9], Normally, the infrarenal part of the inferior vena cava originates from the right supracardinal vein which runs dorsally to the ureter, thus allowing the ureter to lie lateral to the inferior
Fukuoka/Fukushima/Uekane/Higurashi
Retrocaval Ureter
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
The occurrence frequency of inferior caval vein anom alies is not exactly known, although it is believed that they occur in 2-3% of the population [9], On the other hand, retrocaval ureter with clinical symptoms is significantly rare, i.e., incidence of less than 0.1 % of the population [9], Postmortem series, however, have shown an incidence of approximately 9 per 1,000 cases [5, 10]; thus, it appears that a significant number of undetected asymptomatic cases occur. It should be noted that children are seldom diagnosed [3], and the cases which have been are probably
mended [3], On the other hand, symptomatic patients having flow obstruction should undergo surgery to release the ureteral obstruction and restore normal renal func tion. This is normally performed by resecting either the upper ureter, as in the present case, or the renal pelvis, freeing it from its retrocaval position, followed by restor ing the continuity of the ureter in front of the inferior caval vein. With the exception of a few cases involving stricture formation at the site of anastomosis, calculus formation, and persistent infection, satisfactory results have generally been obtained using these surgical proce dures. Progressive damage has been reported to occur later in life with surgical difficulties and poor renoureteric recovery being encountered [3]. Five types of anomalies concerning the anatomic rela tions between the ureter and the inferior caval vein were originally reported [5, 15]. However. Bateson and Atkin son [14], Crosse et al. [2], and Kenawi and Williams [3] introduced a new radiographic classification for retro caval ureter using two category types. In the most com mon of the two categories, i.e., type 1 retrocaval ureter, severe or moderate hydronephrosis and marked medial deviation of the ureter with an S- or fish-hook-shaped deformity occurs. The flow obstruction appears at the edge of the iliopsoas muscle, at which point the ureter deviates cephalad before passing behind the vena cava. Radiological examinations show our case to be a type 1 retrocaval ureter. As to the urinary flow obstruction mechanism in this type, Bateson and Atkinson [14] recently found that compression by the inferior vena cava is not an important factor in producing the obstruction since narrowing occurs at the lateral border of the psoas muscle where the ureter turns upwards. In our patient, microscopic observation of the retropositioned ureter in dicated nonspecific inflammation and a noncompressed ureteral cavity (fig. 3), as well as showing the narrowest part of the ureter to be located at the lateral border of the psoas (fig. 1, 2). These results therefore support the find ing of Bateson and Atkinson [14]. In contrast, the type 2 retrocaval ureter shows a lesser degree or absence of hydronephrosis and slight medial deviation of the ureter, having a sickle-shaped curve that runs its length behind the cava. The ureter is less severely deviated, and the obstruction point is located at the lat eral wall of the inferior vena cava.
59
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
vena cava. In this particular anomaly, the more ventral infrarcnal subcardinal vein persists, thereby obliging the more dorsally placed ureter to pass behind and around it as the developing metanephros ascends from the pelvis to its final lumbar position. Patients with retrocaval ureter commonly suffer from flank pain, occasional hematuria, or urinal infection [3]. In cases of recurrent pyelonephritis, as in our case, retro caval ureter should be suspected. The formation of renal stones may also occur [3, 12]. Due to the gradual develop ment of associated hydronephrosis, patients most often develop complications during their thirties and forties [3, 5]. With regard to pregnancy, the patient delivered her first baby at 27 years, and 6 months later, while 8 weeks pregnant with her second baby, the first incidence of pyelonephritis occurred, although the baby was delivered without any further complications. At 30 years, she deliv ered her third baby without any complications. Two more instances occurred at 31 years (September and October), therefore the patient’s history does not support the find ing that pregnancy inevitably exacerbates the compres sion of the ureter to induce pyelonephritis [4], Excretory radiographs show the dilated proximal part of the ureter to have a reversed J-shaped appearance as it passes from the pelvis under the vena cava at the third or fourth lumbar vertebra (fig. 1) [6 , 7], Varying degrees of pronounced hydronephrosis are also noted proximal to the flow-obstructing compression area. In contrast, an excretory urography often fails to visualize the portion of the ureter beyond the J-shaped hook [3], Medial deviation of the middle third of the right ureter to the level of the pedicles of L 3 and L4 may be caused by retroperitoneal fibrosis, a retroperitoneal mass, or retrocaval ureter [8], Thus, as a further diagnostic procedure, retrograde pyelo graphy is important and sufficient, and will disclose the typically seen ‘S' image, i.e., permanent proximity of the ureter to the lower vertebral column. Additionally, cavography performed simultaneously with an indwelling catheter in the ureter is able to show the anatomical rela tions between the ureter and the inferior caval vein [2, 13], The standard treatment for retrocaval ureter is resec tion of the retrocaval ureter section and an end-to-end anastomosis anterior to the vena cava [6]. Occasionally, excision of the redundant ureter is necessary to prevent kinking and continued obstruction [3, 14], The kidney is saved, unless it has been severely damaged by flow obstruction and/or infection. In patients without symp toms, having either normal flow or a slight obstruction which is not increasing, periodic observation is recom
1 Hochstettcr F: Beiträge zur Entwicklungsge schichte des Venensystems der Amnioten. MorpholJahrb 1893:20:543-561. 2 Crosse JEW. Sodcrdahl DW, Teplick SK. Clark RE: Nonobstructive circumcaval (retrocaval) ureter - A case report o f 2 cases. Radiology 1975:116:69-71. 3 Kenawi MM. Williams Di: Circumcaval ure ter: A report of four cases in children with a review of the literature and a new classifica tion. Br J Urol 1976;48:183-192. 4 Huntington GS, McClure CFW: The develop ment of veins in the domestic cat (Felix domestica) with special reference. I) to the shape taken by the supracardinal veins in the devel opment of the postcava and azygos veins and to the interpretation of the variant conditions of the postcava and its tributaries, as found in the adult. Anat Ree 1920:20:1-21.
60
5 Nielsen BP: Retrocaval ureter: Report of a case. Acta Radiol 1959:51:179-188. 6 Brito RR. Zulian RZ, Albuquerque J, Borges JB: Retrocaval ureter. Br J Urol 1973:45:144— 152. 7 Eidelman A. Yural E. Simon D. Sibi Y: Retro caval ureter. Eur Urol 1978:4:279-281. 8 Anger PH, Stolz JL. Miller WT: Retroperito neal fibrosis: An analysis of the clinical spec trum and roentgenographic signs. Am J Roent genol 1973;119:812-821. 9 Chuang VP. Mena CE. Hoskins PA: Congeni tal anomalies of the inferior vena cava. Review of embryogenesis and presentation of a simpli fied classification. Br J Radiol 1974:47:206213. 10 Heslin JE. Mamonas C: Retrocaval ureter. Re port of four cases and review of literature. J Urol 1951:65:212-222.
11 Koinuma N: A clinical study of retrocaval ure ter. Nishinihon J Urol 1980:4523:767-769. 12 Ekstroem T. Nilsson AE: Retrocaval ureter. Two roentgenographically diagnosed and sur gically corrected cases. Acta Chir Scand 1959: 1 18:53-59. 13 Hellsten S, Grabe M, Nylander G: Retrocaval ureter. Acta Chir Scand 1980:146:225-228. 14 Bateson EM, Atkinson D: Circumcaval ureter: A new classification. Clin Radiol 1969:20:173177. 15 Bohn CSL: Retrocaval ureter. Nord Med 1956: 55:641-644.
Fukuoka/Fukushima/Uekane/Higurashi
Retrocaval Ureter
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 7:16:07 PM
References
