Congenital and Iatrogenic Incontinence: Ectopic Ureter, Ureterocele, and Urogenital Sinus
Urinary incontinence in the pediatric population may be the presenting or sentinel symptom in unveiling an underlying congenital anomaly of the genitourinary tract. Development of the urinary system is multifactorial and complex, and even small variants i
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Keara N. DeCotiis, Liza M. Aguiar, and Anthony A. Caldamone
21.1 Ectopic Ureter 21.1.1 Embryology During fetal development, the ureters and the collecting system of the kidneys differentiate from the ureteric bud. At about 28 days of gestation, the ureteric bud develops from the caudal end of the mesonephric duct in response to signals from the metanephric mesenchyme. Bifurcation of the ureteric bud occurs after the developing bud penetrates the metanephric mesenchyme and begins proliferating into the primitive collecting system. Direction of development of the ureteric bud has been demonstrated by manipulation of Gdnf and the Ret receptor, Foxc1/2, Bmp4, Eya1, and Hox11 and expression of other molecules implicating their involvement in appropriate maturation and location. Failure of the interactions between the ureteric bud and nephrogenic and stromal mesenchyme can cause renal agenesis. Early bifurcation of a single ureteric bud causes a bifid ureter which joins into one ureter distally before entering the bladder. Should the mesonephric duct have two distinct ureteric buds develop, complete duplication occurs as each bud independently penetrates the metanephric mesenchyme. The upper pole of the kidney is induced by the cranial bud, and the lower pole is induced by the caudal bud. As development continues, the common excretory duct enters the posterior wall of the urogenital sinus. The caudal ureteric bud is incorporated first, and earlier incorporation allows for more migration laterally within the bladder. The cranial bud is incorporated at a later stage and has less time for migration. As a result, this ureteral orifice is located more medially and caudally K.N. DeCotiis, M.D. • L.M. Aguiar, M.D. • A.A. Caldamone, M.D. (*) Division of Pediatric Urology, Hasbro Children’s Hospital, Warren Alpert School of Medicine, Brown University, Providence, RI, USA e-mail: [email protected] © Springer International Publishing AG, part of Springer Nature 2018 G. Mosiello et al. (eds.), Clinical Urodynamics in Childhood and Adolescence, Urodynamics, Neurourology and Pelvic Floor Dysfunctions, https://doi.org/10.1007/978-3-319-42193-3_21
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within the bladder or sometimes ectopically located into any structure that derives from the caudal mesonephric duct. This relationship between the two ureteral orifices is constant and called the Weigert-Meyer rule. Abnormal insertion sites of ureters into the urogenital sinus may be asymptomatic or be associated with vesicoureteral reflux, incontinence, obstruction, or recurrent infections. In males, ectopic ureters insert above the external sphincter muscle; therefore, incontinence does not occur. Common sites of insertion of an ectopic ureter are the bladder neck, prostatic urethra, ejaculatory duct, vas deferens, and seminal vesicle. For females an ectopic ureter may insert into the bladder neck, vestibule, vagina, or uterus as these are the differentiated organs of the caudal mesenteric duct. Because some of these insertion sites are distal t
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