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Ectopic Vas Deferens
0022-5347 /'15/1205-0597$0?.. OU/0 THE J C
NoveY11be1
Copyright © 1978
in U.S.A.
'I'1he VYilliarns & VVilkins Co.
M. DAVID GIBBONS, WILLIAM J. CROMIE
AND
JOHN VI. DUCKETT, JR
From the Division of Urology, The Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania
ABSTRACT
Two infants with ectopia of the vas deferens are described. To date 11 cases have been reported, comprising a total of 13 ectopic vas insertions, 2 of which are bilateraL A classification of 2 types of ectopic vas is presented with a discussion of their relationship to ureteral ectopias. An embryological hypothesis of a proximal vas precursor segment of the wolffian duct is related closely to Stephens' theory of ureteral development. Ectopia of the vas deferens is a rare congenital anomaly that has been reported previously in only 9 cases. The vas may drain into the ipsilateral ureter or into the bladder. There is an association between vas ectopia and anorectal maldevelopment as well as other ureterotrigonal abnormalities. A hypothesis of distal wolffian duct embryogenesis has been proMackie and Stephens 1 and supported Tanagho 2 to posed explain many of the anomalies of ureteral ectopia. Herein we present a further extrapolation of Mackie and Stephens' theory to explain the embryogenesis ofvas ectopia. Our recent experience with 2 patients prompted this study. CASE REPORTS
Case 1. M. J., a male newborn, was admitted to our hospital for evaluation of a high imperforate anus. No perineal fistula was detected and the patient was able to void with a strong stream. Meconium was present in the urine. A tubular structure that enlarged during voiding was in the left inguinal canal and scrotum. The testes were descended bilaterally and the genitalia were normal. Sacral hypoplasia was present. An excretory urogram (IVP) dernonstrated normal upper urinary tracts with simultaneous visualization of both vasa; the right vas was of normal caliber and the left vas was dilated (fig. 1, A). A voiding cystourethrogram demonstrated no vesicoureteral reflux. However, reflux was noted in both vasa, which appeared to fill from the bladder (fig. 1, B). At cystoscopy the rectourethral fistula was identified in the -~~•-~-0 ~ - urethra. The verumontanum vvas normal in with a prominent central utriculus. ureteral orifices were in the B slightly. The large inferomedial to bladder neck.
The with left on suppressive medication. transvasovasostomy was performed, excising the dilated left vas to its entry into the bladder. Gregoir antireflux procedure vvas done on the proximal vas to prevent vesicovasal reflux. Histologic examination of the proximal left vas disclosed morphology identical to a normal ureter (fig. 1, C). Case 2. J. H., a 1-year-old boy, was admitted to our hospital with a posterior laryngeal cleft communication with the proximal esophagus, which had been diagnosed when he was 3 months old. After primary repair of this fistula urologic evaluation was initiated. The urine was uninfected. An IVP showed pelvic ectopia of the right kidney with a normal left kidney and ureter (fig. 2, A). In the later films a structure resembling a normal ureter could be seen coursing 5 cm.
597
above the bladder before descending down through the inguinal canal (fig. 2, B). A voiding cystourethrogram demonstrated left vesicoureteral reflux. Additionally, reflux was noted into the left vas, a structure that appeared to arise ectopically from the bladder. Its course was similar to that of the structure seen on the IVP (fig. 2, C). Cystoscopy confirmed the orifice of the left vas as patulous and inferomedial to the orifice of the left ureter. Both ureteral orifices were in the A position 2, D). The verumontanum and posterior urethra appeared normal. The right vas was normal on inguinal palpation. The patient is on suppressive medication and a reconstructive operation may be required in the future to avoid epididymitis. REVIEW OF PREVIOUS REPORTS
Anomalous development of the proximal wolffian duct may result in absence or atresia of the vas deferens, as well as abnormalities of the epididymis. These conditions are discovered occasionally at the time of orchiopexy or infertility evaluation. Anomalies of the distal. wolffian duct may result in ectopia of the ureter or ofthe proximal vas deferens. Ectopic insertion of the vas is encountered much less ---~------··--J than an ectopic ureter. Nine cases of implantation proximal vas have been reported previously:3- 9 and are summarized along with our 2 cases in table 1. The age at presentation of this 9.Y!CY!}:?.J'y has ranged from to 30 years, with half of the being established in patients less than 2 old. n,,"'v''--"'""-~ problems include "' u•,uvv,,"u.m, --·-··-·--·-- in half of the cases, nn•or,,,ri,,r laryngeal cleft in 1. A predomiwas noted with 5 cases of right vasci1wolved in 1 case and in UH~f,OCiV•3CO
was found in a third of the reviewed In 3 cases ureteral. was bilateral !ateralis in 2, with no,,r.Priror urethra and bladder neck in 1). Unilateral ureteral ectopia was noted in 1 instance. Vesicoureteral reflux was present in 6 of the 11 cases, affecting a total of 9 of the 13 renal units. EMBRYOLOGY OF VAS-URETERAL ECTOPIA
Ectopia of the vas deferens is rare and, consequently, little embryological explanation has been offered. We believe that an extension of the hypothesis of Mackie and Stephens 1 is as valid in explaining vas deferens ectopia as it is in explaining ureteral ectopia. The concept of trigonal development, with incorporation of the developing vas deferens and ureter into the vesicoureteral canal, has evolved from an understanding of the fate of the common mesonephric duct. Stephens has postulated the exist-
.. 598
GIBBONS, CROMIE AND DUCKETT
FIG. 1
ence of 3 ureteral budding zones on the distal wolffian duct or common mesonephric duct. He maintains that any variation from the central location of the ureteral bud will result in an abnormally placed ureteral orifice. Some degree of renal dysmorphism also may be present in the extreme variations. With this hypothesis, for example, a bud originating from the upper extent of the common mesonephric duct (caudal zone) may result in a ureteral orifice in the H position, resulting in an ectopic ureter draining into the vas or seminal vesicle. Extrapolating this concept of ureteral ectopia further we postulate a theory that may explain vas deferens ectopia. Since the segment of distal wolffian duct immediately adjacent to the common mesonephric duct is destined to become the future juxtaurethral vas deferens we refer to this segment as the proximal vas precursor (table 2 and fig. 3). Normally, this segment becomes incorporated into the vesicourethral canal at the level of the verumontanum, differentiating into the ejaculatory duct, seminal vesicle and juxtaurethral vas. The position of the proximal vas precursor on the wolffian duct, in the transition zone between the common mesonephric duct and upper mesonephric duct, is of fundamental importance. This intermediate position imparts a bipotential capability of the proximal vas precursor. This implies that differentiation of the proximal vas precursor segment may then occur along vas morphology because of its close proximity to the upper mesonephric duct (vasation) or along ureteral morphology because of the close proximity of the common mesonephric duct to its ureteral budding zones (ureterization). Support for this concept of the undifferentiated, bipotential nature of the proximal vas precursor is provided in 2 instances (cases 9 and 10 in table 1) where the ectopic vas had the h istologic appearance of a ureter . Theoretically, if the proximal vas precursor encroaches onto the upper ureteral budding segment of the common mesonephric duct, then a bipotential capability is imparted to this altered upper segment. This segment may then develop either vas (vasation) or ureteral (ureterization) morphology. Encroachment onto this segment of the common mesonephric duct will carry the insertion of the vas into the bladder (fig. 4). Encroachment further down onto the common mesonephric
duct may even impinge upon the ureteral bud itself, leading to an ectopic insertion of the vas into the ureter (fig. 5). Other variations are possible. If the proximal vas precursor involves the ureteral bud, theoretically, the vas may insert along the normal ureter, having a higher ectopic insertion closer to the renal pelvis (fig. 6). Thus, both cases of high insertion of the vas into the ureter (cases 8 and 9 in table 1) can be explained by postulating a ureteral bud arising from the bipotential proximal vas precursor. In both cases the ureter maintained ureteral morphology because of the potential of the proximal vas precursor to ureterize. In 2 cases (cases 9 and 10 in table 1) the vas deferens was ureterized and appeared histologically as a ureter. In contradistinction, vas deferens morphology may be imparted to a ureteral bud originating from the bipotential proximal vas precursor (vasation of the ureteral bud). Recently, we observed this variant in a female newborn with cloaca! exstrophy and a duplex collecting system. Development identical to vas deferens was found in the distal upper pole ureter (vasation), whereas the proximal upper pole ureter assumed normal ureteral morphology. Combined vasation and ureterization of the upper pole ureteral bud, arising from the bipotential proximal vas precursor, provides an explanation for this anomaly (fig. 7). Because the seminal vesicle originates from the portion of the wolffian duct that is the proximal vas precursor, faulty development or agenesis of the seminal vesicle may be expected with vas ectopia. Indeed, in all cases reviewed, including our own, this was the rule and its occurrence is readily predictable. In cases of vasovesical ectopia uptake of the ureter into the developing urinary tract occurs normally, with the ultimate position of the ureteral orifice being dependent upon its ureteral budding zone. The proximal vas precursor, having encroached onto the common mesonephric duct, closely follows the migrating ureteral bud, resulting in an ectopic vas draining anywhere from the ipsilateral ureteral orifice to the posterior urethra. The closer the proximal vas precursor is to the ureteral bud the closer the insertion of the vas is to the ipsilateral ureteral orifice. Thus, the ectopic vas orifice may be located a nywhere along the ectopic u reteral pathway10 but may not be more lateral than the ureteral orifice.
ECTOPIC VAS DE FE RENS
LU
FIG. 2
O')
0 0
TABLE 1
No.
Reference Seitzman and Patton"
2
Alfert and Gillenwater'
3 4
Tejmarova and Paces" Borger and Belman"
5 6
Redman and Sulieman'
7
Reisman~ Boles and associates"
8
9
10
11
Present report
Presenting Age (yrs.)
Presenting Problem
Side and Site of Vas Insertion
Associated Anomalies Cystoscopic Findings Urologic
Rt. orifice in posterior urethra, It. orifice at bladder neck, absent trigone
11
Azotemia, urinary tract infection
Rt. vasoureteral
Bilat. single ureteral ectopia, bilat. hydroureteronephrosis
None
7
Hypospadias and cryptorchidism
Lt. vasoureteral
None
Hematuria Imperforate anus
Lt. vasovesical Rt. vasoureteral
Bilat. cryptorchidism with perinea! hypospadias, absent seminal vesicles Lt. renal agenesis Non-functioning rt. kidney, rt. vesicoureteral reflux Bilat. vesicoureteral reflux, rt. intrarenal reflux Bilat. vesicoureteral reflux
None Supralevator imperforate anus with congenital rectal stenosis
Supralevator imperforate anus
Ectopia lateralis, bilat.
Posterior laryngeal cleft
Normal
30 Newborn Newborn 13
Rt. vasoureteral Urinary tract infection
Bilat. vasoureteral
Acute rt. epididymitis Epididymitis and scrotal abscess
Rt. vasovesical Rt. vasoureteral, partial duplication to lower pole ureter
Newborn
Epididymitis and scrotal abscess
Rt. vasoureteral mid ureter
Newborn
Imperforate anus, It. scrotal swelling with voiding
Vasovesical, bilat.
None Bilat. vesicoureteral reflux, hydroureteronephrosis, neuropathic bladder, chronic rt. pyelonephritis Rt. vesicoureteral reflux with ectopic rt. ureter (dome of bladder), rt. dysplastic kidney Sacral dysgenesis
Posterior laryngeal cleft
Lt. vasovesical
Lt. vesicoureteral reflux
13
2
Treatment
Gastrointestinal
None Supralevator imperforate anus and fistula Supralevator imperforate anus and fistula None
Rt. reimplant
0 .... bi bi 0
z 00
Rt. nephroureterectomy Vesicostomy Ectopia lateralis, bilat.
Bilat. reimplant, vas ligation
No valves
Fistula division, rt. nephroureterectomy, incision and drainage of scrotal abscess Rt. nephroureterectomy, rt. orchiectomy
Supralevator imperforate anus with congenital rectal stenosis
Lt.-to-rt. transvasovasostomy, rt. antireflux procedure on ectopic vas
0
~
is:
l;;i
~ti ti
§ ~ l:i:J
~
601
ECTOPIC VAS DE FE RENS TABLE
Common Mesonephric Duct A-normal (fig. 3)
Trigone
B - vasovesical ectopia (fig. 4)
Trigone
C -vasoureteral ectopia into lower ureter (fig. 5) D-vasoureteral ectopia into mid or upper ureter (fig. 6) E- upper pole ureter of complete duplex system (fig. 7)
Trigone Trigone Trigone
2. Fate of the wolffian (mesonephric) duct (Uni potential) Upper Mesonephric Duct
(Bipotential) Proximal Vas Precursor Vasation-vas deferens seminal vesicles ejaculatory duct Vasation or ureterization- ectopic vas, draining into bladder Vasation or ureterization- ectopic vas, draining into lower ipsilateral ureter Ureterization- ureter, joining ureterized ureteral bud Vasation of upper proximal vas precursor and upper bud U reterization of lower proximal vas precursor and lower bud
Vas deferens Epididymis Vas deferens Epididymis Vas deferens Epididymis Vas deferens Epididymis Vas deferens Epididymis
Ureteral Bud U reterization - ureter Ureterization-ureter, orthotopic or ectopic Ureterization-ureter, orthotopic or ectopic U reterization- high ureter, joining ureterized proximal vas precursor Vasation of upper uretera!" ou{ issuing from upper proximal vas precursor Ureterization of lower ureteral bud, issuing from lower proximal vas precursor
WO
FIG . 3. Three distinct ureteral budding zones form common mesonephric duct (CMD). Common mesonephric duct is trigonal precursor following absorption into urogenital sinus (UGS). Wolffian duct (WD) is comprised of 3 basic segments: upper mesonephric duct (UMD) normally becomes distal vas deferens (VD) and epididymis; proximal vas precursor (PVP) becomesjuxtaurethral vas, ejaculatory duct (ED) and seminal vesicle (SV) , and common mesonephric duct. Note no seminal vesicle differentiation in vas ectopias. Short common mesonephric duct in vasovesical and vasoureteral ectopia results in muscular deficient trigone, predisposing to vesicoureteral reflux. Ca, caudoureteral budding zone. 0, orthotopic ureteral budding zone. Cr, cranio-ureteral budding zone. UB, ureteral bud. MB, metanephric blastema. K, kidney. U, ureter. B, bladder.
0 FIG. 4
In cases of vasoureteral ectopia the undifferentiated proximal vas precursor actually encroaches upon or becomes incorporated into the ureteral bud on the wolffian duct. The vas will then drain directly into the ipsilateral ureter, regardless of the position of the ureteral orifice. It should be noted that this anatomical arrangement is to be distinguished from that of an ectopic ureter draining into the vas deferens. Three variations of vasoureteral ectopia have been reported based on the ureteral orifice positioning. An orthotopic ureteral orifice results if the proximal vas precursor encroaches upon a bud arising from the A (orthotopic) position on the common mesonephric duct. A cranio-ectopic orifice (ectopia lateralis) results from proximal vas precursor encroachment upon a bud in the B-C-D position (cranial common meso-
nephric duct zone) . A caudo-ectopic orifice results from proximal vas precursor encroachment on an E-F-G position bud (caudal common mesonephric duct zone) . We have not encountered any examples of vasoureteral e~topia in duplex systems. Theoretically, however, the proxim)i.l ,.v as pre,mrsor would encroach upon the ureteral bud, intercepting the cranial aspect of the metanephric blastema. This would result in a vas, ectopic into the ureter and draining the upper renal pole. Boles and associates reported on 1 patient with an incomplete duplication and vasoureteral ectopia into the lower portion of the Y ureter. 9 However, our hypothesis is still valid in this case, since a bifid ureter arises from a single ureteral bud. In both of our cases the appearance and position of the
----
-
·-"" --
]
602
GIBBONS, CROMIE AND DUCKETT
FIG. 5
FIG. 6
0 FIG. 7
verumontanum were unaffected by the absence,of the juxtaurethral vas deferens. The verumontanum marks the embryonic termination of the paired miillerian ducts at Muller's tubercle and in cases of vas deferens ectopia its development does not appear to be wolffian dependent. There is a predictably high association of vas ectopia with anorectal malformations and other anomalies of the ureterotrigonal unit (reflux and ectopia) because of the common embryologic activity of all these structures. The high incidence of vesicoureteral reflux associated with vas ectopia (70 per cent) may be attributed to relative trigonal hypoplasia. The shortened segment of the common mesonephric duct (trigonal precursor) resulting from proximal vas precursor encroachment into the common mesonephric duct may result in a muscular deficient trigone, especially when the orifice is
in the B-C-D position. A lateral ureteral orifice position may then result in inadequate tunnel length, an incompetent ureterovesical junction and vesicoureteral reflux. CLASSIFICATION OF V AS-URETERAL ECTOPIA
In an effort to solidify the implications of faulty distal wolffian duct development and interrelate these events with those concepts of Mackie and Stephens, 1 and Tanagho, 2 we propose a classification of vas-ureteral ectopia. It is helpful to remember that ureteral ectopia into the vas, seminal vesicle or ejaculatory duct (the H position orifice) evolves from a ureteral bud originating from the highest possible position on the common mesonephric duct, immediately adjacent to the proximal vas precursor segment. The presence or absence of proximal vas precursor encroachment upon the common mes-
603
ECTOPIC VAS DEFERENS
~IG. 8. Classification of vas-u~eteral ectopia. Common mesonephric duct in ureteral ectopia with H position orifice into A seminal vesicle and_ B, v:as deferei:i,s. Proxm:1;al vas precursor in vas edoIJia. C, vasovesical-vas drai~s into ipsilateral side of bladder. Orthotopic uretera! ori_fice 1;n J:.. position. Ectopic urete~al orifice m cramo-displac_e1 CB-C-D) '.'Ind caudo-di~placE:d (E-F-G) positions. D, vasoureteralv~s drams mto ipsilateral ureter. Orthotopic ureteral orifice m A position. Ectopic ureteral orifice m cranio-displaced (B-C-D) and caudodisplaced (E-F-G) positions. Complete ureteral duplication; vas drains into upper pole ureter.
onephric duct as well as the line of proximal vas precursor differentiation then decides whether the event of H-type ureteral ectopia or vas deferens ectopia will ensue (fig. 8). MANAGEMENT
The aim of short-term and long-term management of patients with ectopia of the vas deferens is the prevention of urinary infection and epididymitis. Complications may occur either from vesicoureteral reflux with pyelonephritis, vesicoureterovasal reflux or vesicovasal reflux with epididymitis and scrotal abscess. Renal function in these patients can range from normal to severely impaired. In those cases reviewed the 2 factors contributing to renal deterioration were associated ectopia of the ureteral orifice, presumably subtending hypoplastic or dysplastic parenchyma and vesicoureteral reflux. Renal dysplasia was confirmed histologically in 2 cases, 1 of which was associated with a markedly cranio-ectopic ureter (cases 8 and 9 in table 1). The condition of unilateral vas ectopia affords potential for fertility because of the presumed normal contralateral vas ductal system. In instances of bilateral vas ectopia the potential for sterility is significant. Primary reconstruction seems unwarranted because of the associated technical difficulties and the predictable absence of seminal vesicles. The operative procedure performed in case 1 was designed to prevent reflux into the common vas and to avoid ablative surgery at this age. CONCLUSION
Ectopia of the vas deferens into the bladder, ureter or contralateral vas occurs infrequently. Its association with malformations of the urinary and gastrointestinal tracts has been well documented.
We have postulated the existence of the proximal vas precursor, a short segment of wolffian duct located immediately proximal to the common mesonephric duct. Independent ureterovasal development may occur in 1 of 3 ways: 1) normal proximal vas precursor differentiation into juxtaurethral vas deferens, seminal vesicles and ejaculatory duct, terminating at the verumontanum; 2) faulty ureteral budding from the common mesonephric duct, resulting in a dilated ectopic ureter in the H position subtending a severely hypodysplastic kidney or 3) encroachment upon or incorporation into the ureteral bud by the undifferentiated proximal vas precursor. The result is an ectopic proximal vas deferens without seminal vesicle formation. The ectopic vas may open into the bladder or ipsilateral ureter and may have ureteral or vas deferens morphology. Renal morphology depends upon the ureteral orifice position and is independent of the class or degree ofvas ectopia. Although a great deal of effort has been devoted toward an understanding of the normal and faulty development of the ureterotrigonal unit little is known about the ultimate differentiation of the distal wolffian duct and its tautological malformations. There is currently a healthy debate over the validity of the concepts of Mackie and Stephens, 1 and Tanagho 2 on ureter-vas-trigonal relationships and their application in the explanation of specific clinical situations. We are offering a classification of vas deferens ectopia and a theoretical embryological explanation related to Mackie and Stephens' 1 concept in an effort to stimulate more basic and clinical research in this intriguing subject. REFERENCES
1. Mackie, G. G. and Stephens, F. D.: Duplex kidneys: a correlation
of renal dysplasia with position of the ureteral orifice. J.
,~ :{;
604
GIBBONS, CROMIE AND DUCKETT
Urol., 114: 274, 1975. 2. Tanagho, E. A.: Embryologic basis for lower ureteral anomalies: a hypothesis. Urology, 7: 451, 1976. 3. Seitzman, D. M. and Patton, J. F.: Ureteral ectopia: combined ureteral and vas deferens anomaly. J. Urol., 84: 604, 1960. 4. Alfert, H. J. and Gillenwater, J. Y.: Ectopic vas deferens communicating with lower ureter: embryological considerations. J. Urol., 108: 172, 1972. 5. Tejmarova, V. J. and Paces, V.: Mfuidung des linken Ductus deferens in die Harnblase. Fortschrgeb. Roentgenstr. Nuklearmed, 119: 637, 1973. 6. Borger, J. A. and Belman, A. B.: Uretero-vas deferens anasto-
7. 8. 9. 10.
mosis associated with imperforate anus: an embryologically predictable occurrence. J. Pediat. Surg., 10: 255, 1975. Redman, J. F. and Sulieman, J. S.: Bilateral vasal-ureteral communications. J. Urol., 116: 808, 1976. Reisman, D. D.: Epididymitis owing to ectopic ejaculatory duct: a case report. J. Urol., 117: 540, 1977. Boles, E. T., Lobe, T. E. and Hamoudi, A.: Congenital vas deferens-ureteral connection. J. Pediat. Surg., 13: 41, 1978. Stephens, F. D.: Anatomical vagaries of double ureters. In: Congenital Malformations of the Rectum, Anus, and GenitoUrinary Tracts. London: E. & S. Livingstone, Ltd., chapt. 11, p. 174, 1963.
NoveY11be1
Copyright © 1978
in U.S.A.
'I'1he VYilliarns & VVilkins Co.
M. DAVID GIBBONS, WILLIAM J. CROMIE
AND
JOHN VI. DUCKETT, JR
From the Division of Urology, The Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania
ABSTRACT
Two infants with ectopia of the vas deferens are described. To date 11 cases have been reported, comprising a total of 13 ectopic vas insertions, 2 of which are bilateraL A classification of 2 types of ectopic vas is presented with a discussion of their relationship to ureteral ectopias. An embryological hypothesis of a proximal vas precursor segment of the wolffian duct is related closely to Stephens' theory of ureteral development. Ectopia of the vas deferens is a rare congenital anomaly that has been reported previously in only 9 cases. The vas may drain into the ipsilateral ureter or into the bladder. There is an association between vas ectopia and anorectal maldevelopment as well as other ureterotrigonal abnormalities. A hypothesis of distal wolffian duct embryogenesis has been proMackie and Stephens 1 and supported Tanagho 2 to posed explain many of the anomalies of ureteral ectopia. Herein we present a further extrapolation of Mackie and Stephens' theory to explain the embryogenesis ofvas ectopia. Our recent experience with 2 patients prompted this study. CASE REPORTS
Case 1. M. J., a male newborn, was admitted to our hospital for evaluation of a high imperforate anus. No perineal fistula was detected and the patient was able to void with a strong stream. Meconium was present in the urine. A tubular structure that enlarged during voiding was in the left inguinal canal and scrotum. The testes were descended bilaterally and the genitalia were normal. Sacral hypoplasia was present. An excretory urogram (IVP) dernonstrated normal upper urinary tracts with simultaneous visualization of both vasa; the right vas was of normal caliber and the left vas was dilated (fig. 1, A). A voiding cystourethrogram demonstrated no vesicoureteral reflux. However, reflux was noted in both vasa, which appeared to fill from the bladder (fig. 1, B). At cystoscopy the rectourethral fistula was identified in the -~~•-~-0 ~ - urethra. The verumontanum vvas normal in with a prominent central utriculus. ureteral orifices were in the B slightly. The large inferomedial to bladder neck.
The with left on suppressive medication. transvasovasostomy was performed, excising the dilated left vas to its entry into the bladder. Gregoir antireflux procedure vvas done on the proximal vas to prevent vesicovasal reflux. Histologic examination of the proximal left vas disclosed morphology identical to a normal ureter (fig. 1, C). Case 2. J. H., a 1-year-old boy, was admitted to our hospital with a posterior laryngeal cleft communication with the proximal esophagus, which had been diagnosed when he was 3 months old. After primary repair of this fistula urologic evaluation was initiated. The urine was uninfected. An IVP showed pelvic ectopia of the right kidney with a normal left kidney and ureter (fig. 2, A). In the later films a structure resembling a normal ureter could be seen coursing 5 cm.
597
above the bladder before descending down through the inguinal canal (fig. 2, B). A voiding cystourethrogram demonstrated left vesicoureteral reflux. Additionally, reflux was noted into the left vas, a structure that appeared to arise ectopically from the bladder. Its course was similar to that of the structure seen on the IVP (fig. 2, C). Cystoscopy confirmed the orifice of the left vas as patulous and inferomedial to the orifice of the left ureter. Both ureteral orifices were in the A position 2, D). The verumontanum and posterior urethra appeared normal. The right vas was normal on inguinal palpation. The patient is on suppressive medication and a reconstructive operation may be required in the future to avoid epididymitis. REVIEW OF PREVIOUS REPORTS
Anomalous development of the proximal wolffian duct may result in absence or atresia of the vas deferens, as well as abnormalities of the epididymis. These conditions are discovered occasionally at the time of orchiopexy or infertility evaluation. Anomalies of the distal. wolffian duct may result in ectopia of the ureter or ofthe proximal vas deferens. Ectopic insertion of the vas is encountered much less ---~------··--J than an ectopic ureter. Nine cases of implantation proximal vas have been reported previously:3- 9 and are summarized along with our 2 cases in table 1. The age at presentation of this 9.Y!CY!}:?.J'y has ranged from to 30 years, with half of the being established in patients less than 2 old. n,,"'v''--"'""-~ problems include "' u•,uvv,,"u.m, --·-··-·--·-- in half of the cases, nn•or,,,ri,,r laryngeal cleft in 1. A predomiwas noted with 5 cases of right vasci1wolved in 1 case and in UH~f,OCiV•3CO
was found in a third of the reviewed In 3 cases ureteral. was bilateral !ateralis in 2, with no,,r.Priror urethra and bladder neck in 1). Unilateral ureteral ectopia was noted in 1 instance. Vesicoureteral reflux was present in 6 of the 11 cases, affecting a total of 9 of the 13 renal units. EMBRYOLOGY OF VAS-URETERAL ECTOPIA
Ectopia of the vas deferens is rare and, consequently, little embryological explanation has been offered. We believe that an extension of the hypothesis of Mackie and Stephens 1 is as valid in explaining vas deferens ectopia as it is in explaining ureteral ectopia. The concept of trigonal development, with incorporation of the developing vas deferens and ureter into the vesicoureteral canal, has evolved from an understanding of the fate of the common mesonephric duct. Stephens has postulated the exist-
.. 598
GIBBONS, CROMIE AND DUCKETT
FIG. 1
ence of 3 ureteral budding zones on the distal wolffian duct or common mesonephric duct. He maintains that any variation from the central location of the ureteral bud will result in an abnormally placed ureteral orifice. Some degree of renal dysmorphism also may be present in the extreme variations. With this hypothesis, for example, a bud originating from the upper extent of the common mesonephric duct (caudal zone) may result in a ureteral orifice in the H position, resulting in an ectopic ureter draining into the vas or seminal vesicle. Extrapolating this concept of ureteral ectopia further we postulate a theory that may explain vas deferens ectopia. Since the segment of distal wolffian duct immediately adjacent to the common mesonephric duct is destined to become the future juxtaurethral vas deferens we refer to this segment as the proximal vas precursor (table 2 and fig. 3). Normally, this segment becomes incorporated into the vesicourethral canal at the level of the verumontanum, differentiating into the ejaculatory duct, seminal vesicle and juxtaurethral vas. The position of the proximal vas precursor on the wolffian duct, in the transition zone between the common mesonephric duct and upper mesonephric duct, is of fundamental importance. This intermediate position imparts a bipotential capability of the proximal vas precursor. This implies that differentiation of the proximal vas precursor segment may then occur along vas morphology because of its close proximity to the upper mesonephric duct (vasation) or along ureteral morphology because of the close proximity of the common mesonephric duct to its ureteral budding zones (ureterization). Support for this concept of the undifferentiated, bipotential nature of the proximal vas precursor is provided in 2 instances (cases 9 and 10 in table 1) where the ectopic vas had the h istologic appearance of a ureter . Theoretically, if the proximal vas precursor encroaches onto the upper ureteral budding segment of the common mesonephric duct, then a bipotential capability is imparted to this altered upper segment. This segment may then develop either vas (vasation) or ureteral (ureterization) morphology. Encroachment onto this segment of the common mesonephric duct will carry the insertion of the vas into the bladder (fig. 4). Encroachment further down onto the common mesonephric
duct may even impinge upon the ureteral bud itself, leading to an ectopic insertion of the vas into the ureter (fig. 5). Other variations are possible. If the proximal vas precursor involves the ureteral bud, theoretically, the vas may insert along the normal ureter, having a higher ectopic insertion closer to the renal pelvis (fig. 6). Thus, both cases of high insertion of the vas into the ureter (cases 8 and 9 in table 1) can be explained by postulating a ureteral bud arising from the bipotential proximal vas precursor. In both cases the ureter maintained ureteral morphology because of the potential of the proximal vas precursor to ureterize. In 2 cases (cases 9 and 10 in table 1) the vas deferens was ureterized and appeared histologically as a ureter. In contradistinction, vas deferens morphology may be imparted to a ureteral bud originating from the bipotential proximal vas precursor (vasation of the ureteral bud). Recently, we observed this variant in a female newborn with cloaca! exstrophy and a duplex collecting system. Development identical to vas deferens was found in the distal upper pole ureter (vasation), whereas the proximal upper pole ureter assumed normal ureteral morphology. Combined vasation and ureterization of the upper pole ureteral bud, arising from the bipotential proximal vas precursor, provides an explanation for this anomaly (fig. 7). Because the seminal vesicle originates from the portion of the wolffian duct that is the proximal vas precursor, faulty development or agenesis of the seminal vesicle may be expected with vas ectopia. Indeed, in all cases reviewed, including our own, this was the rule and its occurrence is readily predictable. In cases of vasovesical ectopia uptake of the ureter into the developing urinary tract occurs normally, with the ultimate position of the ureteral orifice being dependent upon its ureteral budding zone. The proximal vas precursor, having encroached onto the common mesonephric duct, closely follows the migrating ureteral bud, resulting in an ectopic vas draining anywhere from the ipsilateral ureteral orifice to the posterior urethra. The closer the proximal vas precursor is to the ureteral bud the closer the insertion of the vas is to the ipsilateral ureteral orifice. Thus, the ectopic vas orifice may be located a nywhere along the ectopic u reteral pathway10 but may not be more lateral than the ureteral orifice.
ECTOPIC VAS DE FE RENS
LU
FIG. 2
O')
0 0
TABLE 1
No.
Reference Seitzman and Patton"
2
Alfert and Gillenwater'
3 4
Tejmarova and Paces" Borger and Belman"
5 6
Redman and Sulieman'
7
Reisman~ Boles and associates"
8
9
10
11
Present report
Presenting Age (yrs.)
Presenting Problem
Side and Site of Vas Insertion
Associated Anomalies Cystoscopic Findings Urologic
Rt. orifice in posterior urethra, It. orifice at bladder neck, absent trigone
11
Azotemia, urinary tract infection
Rt. vasoureteral
Bilat. single ureteral ectopia, bilat. hydroureteronephrosis
None
7
Hypospadias and cryptorchidism
Lt. vasoureteral
None
Hematuria Imperforate anus
Lt. vasovesical Rt. vasoureteral
Bilat. cryptorchidism with perinea! hypospadias, absent seminal vesicles Lt. renal agenesis Non-functioning rt. kidney, rt. vesicoureteral reflux Bilat. vesicoureteral reflux, rt. intrarenal reflux Bilat. vesicoureteral reflux
None Supralevator imperforate anus with congenital rectal stenosis
Supralevator imperforate anus
Ectopia lateralis, bilat.
Posterior laryngeal cleft
Normal
30 Newborn Newborn 13
Rt. vasoureteral Urinary tract infection
Bilat. vasoureteral
Acute rt. epididymitis Epididymitis and scrotal abscess
Rt. vasovesical Rt. vasoureteral, partial duplication to lower pole ureter
Newborn
Epididymitis and scrotal abscess
Rt. vasoureteral mid ureter
Newborn
Imperforate anus, It. scrotal swelling with voiding
Vasovesical, bilat.
None Bilat. vesicoureteral reflux, hydroureteronephrosis, neuropathic bladder, chronic rt. pyelonephritis Rt. vesicoureteral reflux with ectopic rt. ureter (dome of bladder), rt. dysplastic kidney Sacral dysgenesis
Posterior laryngeal cleft
Lt. vasovesical
Lt. vesicoureteral reflux
13
2
Treatment
Gastrointestinal
None Supralevator imperforate anus and fistula Supralevator imperforate anus and fistula None
Rt. reimplant
0 .... bi bi 0
z 00
Rt. nephroureterectomy Vesicostomy Ectopia lateralis, bilat.
Bilat. reimplant, vas ligation
No valves
Fistula division, rt. nephroureterectomy, incision and drainage of scrotal abscess Rt. nephroureterectomy, rt. orchiectomy
Supralevator imperforate anus with congenital rectal stenosis
Lt.-to-rt. transvasovasostomy, rt. antireflux procedure on ectopic vas
0
~
is:
l;;i
~ti ti
§ ~ l:i:J
~
601
ECTOPIC VAS DE FE RENS TABLE
Common Mesonephric Duct A-normal (fig. 3)
Trigone
B - vasovesical ectopia (fig. 4)
Trigone
C -vasoureteral ectopia into lower ureter (fig. 5) D-vasoureteral ectopia into mid or upper ureter (fig. 6) E- upper pole ureter of complete duplex system (fig. 7)
Trigone Trigone Trigone
2. Fate of the wolffian (mesonephric) duct (Uni potential) Upper Mesonephric Duct
(Bipotential) Proximal Vas Precursor Vasation-vas deferens seminal vesicles ejaculatory duct Vasation or ureterization- ectopic vas, draining into bladder Vasation or ureterization- ectopic vas, draining into lower ipsilateral ureter Ureterization- ureter, joining ureterized ureteral bud Vasation of upper proximal vas precursor and upper bud U reterization of lower proximal vas precursor and lower bud
Vas deferens Epididymis Vas deferens Epididymis Vas deferens Epididymis Vas deferens Epididymis Vas deferens Epididymis
Ureteral Bud U reterization - ureter Ureterization-ureter, orthotopic or ectopic Ureterization-ureter, orthotopic or ectopic U reterization- high ureter, joining ureterized proximal vas precursor Vasation of upper uretera!" ou{ issuing from upper proximal vas precursor Ureterization of lower ureteral bud, issuing from lower proximal vas precursor
WO
FIG . 3. Three distinct ureteral budding zones form common mesonephric duct (CMD). Common mesonephric duct is trigonal precursor following absorption into urogenital sinus (UGS). Wolffian duct (WD) is comprised of 3 basic segments: upper mesonephric duct (UMD) normally becomes distal vas deferens (VD) and epididymis; proximal vas precursor (PVP) becomesjuxtaurethral vas, ejaculatory duct (ED) and seminal vesicle (SV) , and common mesonephric duct. Note no seminal vesicle differentiation in vas ectopias. Short common mesonephric duct in vasovesical and vasoureteral ectopia results in muscular deficient trigone, predisposing to vesicoureteral reflux. Ca, caudoureteral budding zone. 0, orthotopic ureteral budding zone. Cr, cranio-ureteral budding zone. UB, ureteral bud. MB, metanephric blastema. K, kidney. U, ureter. B, bladder.
0 FIG. 4
In cases of vasoureteral ectopia the undifferentiated proximal vas precursor actually encroaches upon or becomes incorporated into the ureteral bud on the wolffian duct. The vas will then drain directly into the ipsilateral ureter, regardless of the position of the ureteral orifice. It should be noted that this anatomical arrangement is to be distinguished from that of an ectopic ureter draining into the vas deferens. Three variations of vasoureteral ectopia have been reported based on the ureteral orifice positioning. An orthotopic ureteral orifice results if the proximal vas precursor encroaches upon a bud arising from the A (orthotopic) position on the common mesonephric duct. A cranio-ectopic orifice (ectopia lateralis) results from proximal vas precursor encroachment upon a bud in the B-C-D position (cranial common meso-
nephric duct zone) . A caudo-ectopic orifice results from proximal vas precursor encroachment on an E-F-G position bud (caudal common mesonephric duct zone) . We have not encountered any examples of vasoureteral e~topia in duplex systems. Theoretically, however, the proxim)i.l ,.v as pre,mrsor would encroach upon the ureteral bud, intercepting the cranial aspect of the metanephric blastema. This would result in a vas, ectopic into the ureter and draining the upper renal pole. Boles and associates reported on 1 patient with an incomplete duplication and vasoureteral ectopia into the lower portion of the Y ureter. 9 However, our hypothesis is still valid in this case, since a bifid ureter arises from a single ureteral bud. In both of our cases the appearance and position of the
----
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]
602
GIBBONS, CROMIE AND DUCKETT
FIG. 5
FIG. 6
0 FIG. 7
verumontanum were unaffected by the absence,of the juxtaurethral vas deferens. The verumontanum marks the embryonic termination of the paired miillerian ducts at Muller's tubercle and in cases of vas deferens ectopia its development does not appear to be wolffian dependent. There is a predictably high association of vas ectopia with anorectal malformations and other anomalies of the ureterotrigonal unit (reflux and ectopia) because of the common embryologic activity of all these structures. The high incidence of vesicoureteral reflux associated with vas ectopia (70 per cent) may be attributed to relative trigonal hypoplasia. The shortened segment of the common mesonephric duct (trigonal precursor) resulting from proximal vas precursor encroachment into the common mesonephric duct may result in a muscular deficient trigone, especially when the orifice is
in the B-C-D position. A lateral ureteral orifice position may then result in inadequate tunnel length, an incompetent ureterovesical junction and vesicoureteral reflux. CLASSIFICATION OF V AS-URETERAL ECTOPIA
In an effort to solidify the implications of faulty distal wolffian duct development and interrelate these events with those concepts of Mackie and Stephens, 1 and Tanagho, 2 we propose a classification of vas-ureteral ectopia. It is helpful to remember that ureteral ectopia into the vas, seminal vesicle or ejaculatory duct (the H position orifice) evolves from a ureteral bud originating from the highest possible position on the common mesonephric duct, immediately adjacent to the proximal vas precursor segment. The presence or absence of proximal vas precursor encroachment upon the common mes-
603
ECTOPIC VAS DEFERENS
~IG. 8. Classification of vas-u~eteral ectopia. Common mesonephric duct in ureteral ectopia with H position orifice into A seminal vesicle and_ B, v:as deferei:i,s. Proxm:1;al vas precursor in vas edoIJia. C, vasovesical-vas drai~s into ipsilateral side of bladder. Orthotopic uretera! ori_fice 1;n J:.. position. Ectopic urete~al orifice m cramo-displac_e1 CB-C-D) '.'Ind caudo-di~placE:d (E-F-G) positions. D, vasoureteralv~s drams mto ipsilateral ureter. Orthotopic ureteral orifice m A position. Ectopic ureteral orifice m cranio-displaced (B-C-D) and caudodisplaced (E-F-G) positions. Complete ureteral duplication; vas drains into upper pole ureter.
onephric duct as well as the line of proximal vas precursor differentiation then decides whether the event of H-type ureteral ectopia or vas deferens ectopia will ensue (fig. 8). MANAGEMENT
The aim of short-term and long-term management of patients with ectopia of the vas deferens is the prevention of urinary infection and epididymitis. Complications may occur either from vesicoureteral reflux with pyelonephritis, vesicoureterovasal reflux or vesicovasal reflux with epididymitis and scrotal abscess. Renal function in these patients can range from normal to severely impaired. In those cases reviewed the 2 factors contributing to renal deterioration were associated ectopia of the ureteral orifice, presumably subtending hypoplastic or dysplastic parenchyma and vesicoureteral reflux. Renal dysplasia was confirmed histologically in 2 cases, 1 of which was associated with a markedly cranio-ectopic ureter (cases 8 and 9 in table 1). The condition of unilateral vas ectopia affords potential for fertility because of the presumed normal contralateral vas ductal system. In instances of bilateral vas ectopia the potential for sterility is significant. Primary reconstruction seems unwarranted because of the associated technical difficulties and the predictable absence of seminal vesicles. The operative procedure performed in case 1 was designed to prevent reflux into the common vas and to avoid ablative surgery at this age. CONCLUSION
Ectopia of the vas deferens into the bladder, ureter or contralateral vas occurs infrequently. Its association with malformations of the urinary and gastrointestinal tracts has been well documented.
We have postulated the existence of the proximal vas precursor, a short segment of wolffian duct located immediately proximal to the common mesonephric duct. Independent ureterovasal development may occur in 1 of 3 ways: 1) normal proximal vas precursor differentiation into juxtaurethral vas deferens, seminal vesicles and ejaculatory duct, terminating at the verumontanum; 2) faulty ureteral budding from the common mesonephric duct, resulting in a dilated ectopic ureter in the H position subtending a severely hypodysplastic kidney or 3) encroachment upon or incorporation into the ureteral bud by the undifferentiated proximal vas precursor. The result is an ectopic proximal vas deferens without seminal vesicle formation. The ectopic vas may open into the bladder or ipsilateral ureter and may have ureteral or vas deferens morphology. Renal morphology depends upon the ureteral orifice position and is independent of the class or degree ofvas ectopia. Although a great deal of effort has been devoted toward an understanding of the normal and faulty development of the ureterotrigonal unit little is known about the ultimate differentiation of the distal wolffian duct and its tautological malformations. There is currently a healthy debate over the validity of the concepts of Mackie and Stephens, 1 and Tanagho 2 on ureter-vas-trigonal relationships and their application in the explanation of specific clinical situations. We are offering a classification of vas deferens ectopia and a theoretical embryological explanation related to Mackie and Stephens' 1 concept in an effort to stimulate more basic and clinical research in this intriguing subject. REFERENCES
1. Mackie, G. G. and Stephens, F. D.: Duplex kidneys: a correlation
of renal dysplasia with position of the ureteral orifice. J.
,~ :{;
604
GIBBONS, CROMIE AND DUCKETT
Urol., 114: 274, 1975. 2. Tanagho, E. A.: Embryologic basis for lower ureteral anomalies: a hypothesis. Urology, 7: 451, 1976. 3. Seitzman, D. M. and Patton, J. F.: Ureteral ectopia: combined ureteral and vas deferens anomaly. J. Urol., 84: 604, 1960. 4. Alfert, H. J. and Gillenwater, J. Y.: Ectopic vas deferens communicating with lower ureter: embryological considerations. J. Urol., 108: 172, 1972. 5. Tejmarova, V. J. and Paces, V.: Mfuidung des linken Ductus deferens in die Harnblase. Fortschrgeb. Roentgenstr. Nuklearmed, 119: 637, 1973. 6. Borger, J. A. and Belman, A. B.: Uretero-vas deferens anasto-
7. 8. 9. 10.
mosis associated with imperforate anus: an embryologically predictable occurrence. J. Pediat. Surg., 10: 255, 1975. Redman, J. F. and Sulieman, J. S.: Bilateral vasal-ureteral communications. J. Urol., 116: 808, 1976. Reisman, D. D.: Epididymitis owing to ectopic ejaculatory duct: a case report. J. Urol., 117: 540, 1977. Boles, E. T., Lobe, T. E. and Hamoudi, A.: Congenital vas deferens-ureteral connection. J. Pediat. Surg., 13: 41, 1978. Stephens, F. D.: Anatomical vagaries of double ureters. In: Congenital Malformations of the Rectum, Anus, and GenitoUrinary Tracts. London: E. & S. Livingstone, Ltd., chapt. 11, p. 174, 1963.