Urol, int.32: 49-55 (1977)
Duplication of the Renal Pelvis and Blind-Ending Bifid Ureter in Twins Bo Bergman, Göran Hansson and Arne E. V. Nihon Department of Urology, Umeä lasarett, Umeä and Departments of Pathology II and Roentgenology 1, Sahlgrenska sjukhuset, Göteborg
Key Words. Duplication of urinary tract • Blind-ending ureter • Bifid ureter
Schultze (13) summed up 50 cases of blind-ending bifid ureter reported in 1967, but in 1970 the number had risen to 107 (2). Thus, this anatomical variety is not extremely rare. The genesis of blind-ending bifid ureter, however, has been given scant attention in the literature (1, 14, 15). Whitaker and Danks (14) described familial occurrences of duplicated ureters and/or kidneys. They found 16 cases by means of excretory urography in 123 relatives of 39 patients with previously diagnosed duplications. No pattern for the genetic transmission in the families could be traced. The roentgenological diagnosis of a blind-ending bifid ureter is made by performing a retrograde ureteropyelography (5, 8), but the diagnosis may also be carried out by excretory urography if the blind-ending ureter merges not too distally into the other ureter (11). Bifid ureter is supposed to arise from branching of the ureteral bud (2). Duplication with two complete ureters on the same side, however, is assumed to originate from two separate buds growing out from the Wolffian duct. Kidney and ureteral duplications have been described in families where blind-ending ureter was found in other members (14). Nation (10) found ureteral duplication and blind-ending bifid ureter in the same individual. These observations suggest that the genesis of the two conditions may be the same.
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Abstract. Blind-ending bifid ureter in a woman with urinary tract infection and a duplicated renal pelvis in her twin sister are reported. The blind-ending bifid ureter terminat ed as a fibrous cord with a terminal mass of immature renal tissue. This type of ureter may be a transitional form between histologically blind-ending bifid ureter and duplication of the renal pelvis and/or kidneys. Findings in twins support this opinion.
Bergman/Hansson/Nilson
50
Fig. 1. Intravenous pyelography during abdominal compression (a) and after released compression (b). Wide blind-ending bifid ureter, cone-shaped cranially and without connec tion with the renal pelvis. The ureter to the renal pelvis on the same side is normal.
Case Reports
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
The patient is a 23-year-old woman, who had had recurrent urinary infections Cor 3 years. Excretory urography (fig. la , b) and retrograde ureteropyelography (fig. 2a, b) showed a blind-ending ureter emerging into the ureter from the left kidney. The blind ending branch was running laterally to the normal ureter, down to the level of the cranial part of the sacroiliacal joint, where the ureters emerged. The blind-ending ureter was fingerwide. Cranially to the pelvis it gradually narrowed into a cone without connection with the renal pelvis. The renal pelvis appeared normal on the excretory urography. The findings at nephroangiography were normal. Each kidney had one renal artery. At operation it was found that the blind-ending ureter crossed the other ureter, behind it, at the caudal part of the kidney, then continued cranially on the medial side of the renal pelvis. The blind-ending ureter continued from the cone as a fibrous cord which extended 1.5 cm into the renal parenchyma (fig. 3) and terminated as a small bud (fig. 4} which was easily dissected free.
Duplication of the Renal Pelvis
51
Fig. 2. Retrograde pyelography. Ureteral confluence at the cranial part of the sacroiliacal joint.
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Histological examination of the operative specimen showed the ureter to be lined with transitional cell epithelium up to the terminal bud. Signs of a slight chronic inflammation with lymphocytes and plasma cells in the tunica propria were seen. The muscle coat was of ordinary thickness. The terminal cord had a narrow lumen lined with a low, dark epithelium and smooth muscle fibres Were found in the wall. The proximal bud was built up by loose connective tissue with scattered tubular structures, some of them showing a cystic dilata tion. Among these structures small calcified round bodies were seen, as well as some lym phocytes. No glomerular structures were found (fig. 5).
Bergman /Hansson/Nilson
52
Fig. 3. Silk thread in blind-ending bifid ureter. Narrowing cone disappearing into renal parenchyma.
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After the operation the patient has had no symptoms of urinary infection. Several urinary cultures were negative and the postoperative intravenous urography showed normal anatomy of the renal pelvis and ureter. The patient has a twin sister. According to the case record from the delivery only one placenta was found. Erythrocyte and tissue typing showed correspondence between the twins in the following systems: (1) Blood group A2, Rh +, CcDee, Mnss, Le (a-b+), P ,, Kell ( - ) , Fy (a+) Jk (a+). (2) Tissue type HL-A, 2, 11, 7, 27 (AJ). Thus, no evidence for dizygoticity was found. Crossed skin transplantation was not performed. The twin sister reported an episode of urinary infection at the age of 10 years, but has since been symptom free. Urinary culture was negative. Excretory urography showed dupli cated renal pelvis and ureter on the right side. The confluence of the ureters could not be visualized. The cranial renal pelvis was small with few calyces. The caudal pelvis was large with round calyces and the surrounding parenchyma seemed to be dysplastic.
Duplication of the Renal Pelvis
53
Fig. 5. Terminal bud consisting of cellular connective tissue with tubular structures and calcification. Van Gieson. X 375.
Discussion
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The twin sisters showed no evidence of dizygoticy by blood or tissue typing. However, they have not been proved to be monozytic twins, since 25 % of brothers and sisters are identical in blood and tissue groups, inherited according to the second law of Mendel. Crossed skin transplantation, which would have determined whether the twins were monozygotic or not, was not performed. Our findings in a pair of twins support the theory that the blind-ending bifid ureter has the same genesis as duplications of the ureters and the renal pelvis. Occurrence on different sides in twins supports this theory. Morison (9) and Leiter (6) reported discordant anomalies in homozygotic twins and suggested that the cause of such anomalies might be intrauterinary factors. Nation (10) stated that the ureter bud is surrounded by nefrogenic mesenchyma from the very beginning of its growth. Our finding of immature renal tissue in the termi nal mass, as well as an earlier description of immature, connective tissue sur rounding a blind-ending bifid ureter (15), speaks in favour of the opinion that
Bergman /Hansson /Nihon
54
the nephrogenic mesenchyma existed in these two patients, thus supporting the theory proposed by Nation. A narrow cone or a fibrous cord at the end of the ureter has been described in only a few patients (3, 4, 12). The ureter with a cone and/or the fibrous cord may be a transitional form between blind-ending bifid ureter and duplication of the kidney and/or renal pelvis. Blind-ending ureter is occasionally found in patients with urinary infection. The diagnosis may be made by excretory urography only if the blind-ending ureter is retrogradely filled. However, excretory urography does not always re veal the confluence, especially not if it is near the bladder. Retrograde pyelog raphy may, however, visualize the blind-ending ureter and the confluence Lenaghan (7) showed that asynchronous contractions in both branches of the bifid ureter are a fact. He also described retrograde peristaltic waves initiated in one branch when a peristaltic wave in the other branch passed the confluence. This might give rise to dilatation (fig. 1) and residual urine in the blind-ending bifid ureter which might keep an infection and explain stone formation in a blind-ending bifid ureter. Whitaker and Banks (14) found no clinical evidence of urinary tract infections among the 16 traced relatives with ureteral duplications, and therefore suggested that excretory urography should be performed on rela tives of patients with diagnosed ureteral duplication only if the patient in ques tion had clinical or laboratory signs of urinary tract infection. Our patient is free from symptoms from the urinary tract and has negative urinary cultures 6 months after the operation. This fact supports the opinion that the blind-ending bifid ureter should be extirpated in patients with urinary infections. It is well known that concrements in the urinary tracts might keep or even give rise to urinary tract infections, and so a blind-ending ureter with calcification should be extirpated. If a blind-ending bifid ureter is diagnosed and the patient is symptom free, it is unnecessary to extirpate the blind-ending ureter. However, if the renal pelvis belonging to the normal branch of the bifid ureter does not completely cor respond to a normal kidney on the side concerned, we suggest that angiography should be performed to exclude a silent part of the kidney. References
2 3 4 5
Benson, C.D.; Mustard, W.T.; Ravitch, M.M.; Snyder, W.H., and Welch, K.J.: Pediatric surgery, vol. 2, pp. 961-965 (Year Book Med. Publishers, Chicago 1962). Bongi, G. e Cavalchini, R.: Uretere bifido con una branca craniale a fondo cieco. Minerva urol. 22: 45-48 (1970). Hanley, H.G.: Blind-ending duplication of the ureter Br. J. Urol. 17: 50-54 (1945). Herbet, H.: Diverticule de l’uretère. Bull. Soc. Anat. 6: 76-78 (1904). Kretschmer, H.L.: Duplications of ureters at their cistal ends, one pair ending blindly; so-called diverticula of ureters. J. Urol. 30: 61-73 (1933). Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
1
Duplication of the Renal Pelvis 6 7 8 9 10 11 12 13 14 15
55
l.eiter, E.: Horseshoe kidney. Discordance in monozygotic twins. J. Urol. 108: 6 8 3 684 (1972). Lenaghan, D.: Bifid ureters in children. An anatomical, physiological and clinical study. J. Urol. 87: 808-817 (1962). Minder, J.: Double ureter. Z. Urol. 19: 680-683 (1925). Morison, J.E.: Congenital malformations in one of monozygotic twins. Archs Dis. Childh. 24: 214-218 (1949). Nation, E.F.: Duplication of the kidney and ureter. A statistical study of 230 new cases. J. Urol. 51: 456-465 (1944). Olson, O.: Roentgen examination of the kidney and the ureter; in Aiken, Dix, Weyranch and Wildbolz Encyclopedia of urology, p. 72 (Springer, Berlin 1962). Papin, E.: Sur la bifidité urétérale. J. Urol. 23: 127-138 (1927). Schultze, R.: Der blind endende Doppelureter. Z. Urol. 60: 271-289 (1967). Whitaker, J. and Danks, D.M.: A study of the inheritance of duplication of the kidneys and ureters. J. Urol. 95: 176-178 (1966). Wilhelm/, C.M.: A case of double ureter in man with failure of development of the kidney about the aberrant ureter. Anat. Rec. 18: 179-192 (1920).
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
Dr. Bo Bergman, Department of Urology, University of Umeâ, Umeâ Lasarctt, S-901 85 Umeâ (Sweden)
Duplication of the Renal Pelvis and Blind-Ending Bifid Ureter in Twins Bo Bergman, Göran Hansson and Arne E. V. Nihon Department of Urology, Umeä lasarett, Umeä and Departments of Pathology II and Roentgenology 1, Sahlgrenska sjukhuset, Göteborg
Key Words. Duplication of urinary tract • Blind-ending ureter • Bifid ureter
Schultze (13) summed up 50 cases of blind-ending bifid ureter reported in 1967, but in 1970 the number had risen to 107 (2). Thus, this anatomical variety is not extremely rare. The genesis of blind-ending bifid ureter, however, has been given scant attention in the literature (1, 14, 15). Whitaker and Danks (14) described familial occurrences of duplicated ureters and/or kidneys. They found 16 cases by means of excretory urography in 123 relatives of 39 patients with previously diagnosed duplications. No pattern for the genetic transmission in the families could be traced. The roentgenological diagnosis of a blind-ending bifid ureter is made by performing a retrograde ureteropyelography (5, 8), but the diagnosis may also be carried out by excretory urography if the blind-ending ureter merges not too distally into the other ureter (11). Bifid ureter is supposed to arise from branching of the ureteral bud (2). Duplication with two complete ureters on the same side, however, is assumed to originate from two separate buds growing out from the Wolffian duct. Kidney and ureteral duplications have been described in families where blind-ending ureter was found in other members (14). Nation (10) found ureteral duplication and blind-ending bifid ureter in the same individual. These observations suggest that the genesis of the two conditions may be the same.
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
Abstract. Blind-ending bifid ureter in a woman with urinary tract infection and a duplicated renal pelvis in her twin sister are reported. The blind-ending bifid ureter terminat ed as a fibrous cord with a terminal mass of immature renal tissue. This type of ureter may be a transitional form between histologically blind-ending bifid ureter and duplication of the renal pelvis and/or kidneys. Findings in twins support this opinion.
Bergman/Hansson/Nilson
50
Fig. 1. Intravenous pyelography during abdominal compression (a) and after released compression (b). Wide blind-ending bifid ureter, cone-shaped cranially and without connec tion with the renal pelvis. The ureter to the renal pelvis on the same side is normal.
Case Reports
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
The patient is a 23-year-old woman, who had had recurrent urinary infections Cor 3 years. Excretory urography (fig. la , b) and retrograde ureteropyelography (fig. 2a, b) showed a blind-ending ureter emerging into the ureter from the left kidney. The blind ending branch was running laterally to the normal ureter, down to the level of the cranial part of the sacroiliacal joint, where the ureters emerged. The blind-ending ureter was fingerwide. Cranially to the pelvis it gradually narrowed into a cone without connection with the renal pelvis. The renal pelvis appeared normal on the excretory urography. The findings at nephroangiography were normal. Each kidney had one renal artery. At operation it was found that the blind-ending ureter crossed the other ureter, behind it, at the caudal part of the kidney, then continued cranially on the medial side of the renal pelvis. The blind-ending ureter continued from the cone as a fibrous cord which extended 1.5 cm into the renal parenchyma (fig. 3) and terminated as a small bud (fig. 4} which was easily dissected free.
Duplication of the Renal Pelvis
51
Fig. 2. Retrograde pyelography. Ureteral confluence at the cranial part of the sacroiliacal joint.
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
Histological examination of the operative specimen showed the ureter to be lined with transitional cell epithelium up to the terminal bud. Signs of a slight chronic inflammation with lymphocytes and plasma cells in the tunica propria were seen. The muscle coat was of ordinary thickness. The terminal cord had a narrow lumen lined with a low, dark epithelium and smooth muscle fibres Were found in the wall. The proximal bud was built up by loose connective tissue with scattered tubular structures, some of them showing a cystic dilata tion. Among these structures small calcified round bodies were seen, as well as some lym phocytes. No glomerular structures were found (fig. 5).
Bergman /Hansson/Nilson
52
Fig. 3. Silk thread in blind-ending bifid ureter. Narrowing cone disappearing into renal parenchyma.
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
After the operation the patient has had no symptoms of urinary infection. Several urinary cultures were negative and the postoperative intravenous urography showed normal anatomy of the renal pelvis and ureter. The patient has a twin sister. According to the case record from the delivery only one placenta was found. Erythrocyte and tissue typing showed correspondence between the twins in the following systems: (1) Blood group A2, Rh +, CcDee, Mnss, Le (a-b+), P ,, Kell ( - ) , Fy (a+) Jk (a+). (2) Tissue type HL-A, 2, 11, 7, 27 (AJ). Thus, no evidence for dizygoticity was found. Crossed skin transplantation was not performed. The twin sister reported an episode of urinary infection at the age of 10 years, but has since been symptom free. Urinary culture was negative. Excretory urography showed dupli cated renal pelvis and ureter on the right side. The confluence of the ureters could not be visualized. The cranial renal pelvis was small with few calyces. The caudal pelvis was large with round calyces and the surrounding parenchyma seemed to be dysplastic.
Duplication of the Renal Pelvis
53
Fig. 5. Terminal bud consisting of cellular connective tissue with tubular structures and calcification. Van Gieson. X 375.
Discussion
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
The twin sisters showed no evidence of dizygoticy by blood or tissue typing. However, they have not been proved to be monozytic twins, since 25 % of brothers and sisters are identical in blood and tissue groups, inherited according to the second law of Mendel. Crossed skin transplantation, which would have determined whether the twins were monozygotic or not, was not performed. Our findings in a pair of twins support the theory that the blind-ending bifid ureter has the same genesis as duplications of the ureters and the renal pelvis. Occurrence on different sides in twins supports this theory. Morison (9) and Leiter (6) reported discordant anomalies in homozygotic twins and suggested that the cause of such anomalies might be intrauterinary factors. Nation (10) stated that the ureter bud is surrounded by nefrogenic mesenchyma from the very beginning of its growth. Our finding of immature renal tissue in the termi nal mass, as well as an earlier description of immature, connective tissue sur rounding a blind-ending bifid ureter (15), speaks in favour of the opinion that
Bergman /Hansson /Nihon
54
the nephrogenic mesenchyma existed in these two patients, thus supporting the theory proposed by Nation. A narrow cone or a fibrous cord at the end of the ureter has been described in only a few patients (3, 4, 12). The ureter with a cone and/or the fibrous cord may be a transitional form between blind-ending bifid ureter and duplication of the kidney and/or renal pelvis. Blind-ending ureter is occasionally found in patients with urinary infection. The diagnosis may be made by excretory urography only if the blind-ending ureter is retrogradely filled. However, excretory urography does not always re veal the confluence, especially not if it is near the bladder. Retrograde pyelog raphy may, however, visualize the blind-ending ureter and the confluence Lenaghan (7) showed that asynchronous contractions in both branches of the bifid ureter are a fact. He also described retrograde peristaltic waves initiated in one branch when a peristaltic wave in the other branch passed the confluence. This might give rise to dilatation (fig. 1) and residual urine in the blind-ending bifid ureter which might keep an infection and explain stone formation in a blind-ending bifid ureter. Whitaker and Banks (14) found no clinical evidence of urinary tract infections among the 16 traced relatives with ureteral duplications, and therefore suggested that excretory urography should be performed on rela tives of patients with diagnosed ureteral duplication only if the patient in ques tion had clinical or laboratory signs of urinary tract infection. Our patient is free from symptoms from the urinary tract and has negative urinary cultures 6 months after the operation. This fact supports the opinion that the blind-ending bifid ureter should be extirpated in patients with urinary infections. It is well known that concrements in the urinary tracts might keep or even give rise to urinary tract infections, and so a blind-ending ureter with calcification should be extirpated. If a blind-ending bifid ureter is diagnosed and the patient is symptom free, it is unnecessary to extirpate the blind-ending ureter. However, if the renal pelvis belonging to the normal branch of the bifid ureter does not completely cor respond to a normal kidney on the side concerned, we suggest that angiography should be performed to exclude a silent part of the kidney. References
2 3 4 5
Benson, C.D.; Mustard, W.T.; Ravitch, M.M.; Snyder, W.H., and Welch, K.J.: Pediatric surgery, vol. 2, pp. 961-965 (Year Book Med. Publishers, Chicago 1962). Bongi, G. e Cavalchini, R.: Uretere bifido con una branca craniale a fondo cieco. Minerva urol. 22: 45-48 (1970). Hanley, H.G.: Blind-ending duplication of the ureter Br. J. Urol. 17: 50-54 (1945). Herbet, H.: Diverticule de l’uretère. Bull. Soc. Anat. 6: 76-78 (1904). Kretschmer, H.L.: Duplications of ureters at their cistal ends, one pair ending blindly; so-called diverticula of ureters. J. Urol. 30: 61-73 (1933). Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
1
Duplication of the Renal Pelvis 6 7 8 9 10 11 12 13 14 15
55
l.eiter, E.: Horseshoe kidney. Discordance in monozygotic twins. J. Urol. 108: 6 8 3 684 (1972). Lenaghan, D.: Bifid ureters in children. An anatomical, physiological and clinical study. J. Urol. 87: 808-817 (1962). Minder, J.: Double ureter. Z. Urol. 19: 680-683 (1925). Morison, J.E.: Congenital malformations in one of monozygotic twins. Archs Dis. Childh. 24: 214-218 (1949). Nation, E.F.: Duplication of the kidney and ureter. A statistical study of 230 new cases. J. Urol. 51: 456-465 (1944). Olson, O.: Roentgen examination of the kidney and the ureter; in Aiken, Dix, Weyranch and Wildbolz Encyclopedia of urology, p. 72 (Springer, Berlin 1962). Papin, E.: Sur la bifidité urétérale. J. Urol. 23: 127-138 (1927). Schultze, R.: Der blind endende Doppelureter. Z. Urol. 60: 271-289 (1967). Whitaker, J. and Danks, D.M.: A study of the inheritance of duplication of the kidneys and ureters. J. Urol. 95: 176-178 (1966). Wilhelm/, C.M.: A case of double ureter in man with failure of development of the kidney about the aberrant ureter. Anat. Rec. 18: 179-192 (1920).
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:35:34 AM
Dr. Bo Bergman, Department of Urology, University of Umeâ, Umeâ Lasarctt, S-901 85 Umeâ (Sweden)
