F. Douglas Stephens

Duplex Kidneys: A Correlation of Renal Dysplasia with Position of the Ureteral Orifice

A study was made of 51 duplex kidneys, ureters and bladders to assess the types of abnormalities seen in duplex kidneys. The abnormalities affected ectopic and orthotopic segments equally. The occurrence of renal abnormality was closely correlated to the abnormal locations of the segments ureteral orifice. When the orifice was displaced either cranially (orifice positions B, C and D) or caudally (orifices G and H) the orthotopic and ectopic segments, respectively, showed more severe hypoplasia and dysplasia. Faulty embryogenesis is proposed to explain these findings and the importance of endoscopic positioning of the ureteral orifice is emphasized in determining whether heminephrectomy will be necessary.

The Natural History of Reflux and Long-Term Effects of Reflux on the Kidney

Spontaneous cessation of vesicoureteral reflux occurred in 42 per cent of 102 patients. It ceased in 65 per cent of the patients with unilateral reflux, in 50 per cent of those with bilateral reflux in normal caliber ureters and in 9 per cent of those with bilateral dilated ureters. Renal parenchymal changes were seen most frequently in patients with urinary infection after diagnosis. The likelihood of such infections lessened if reflux ceased. Proportionately more male than female subjects were free of infection. Renal damage may follow even 1 episode of infection. Lesions appeared with equal frequency during the entire followup period, whereas urinary infection was more common in the 5-year period after diagnosis. Renal damage was more likely to occur in kidneys that were already abnormal. Reflux should be controlled surgically if urinary infections occur after diagnosis and during long-term chemotherapy and careful observation. In the absence of infection indications for operation are infrequent. Non-surgical management may apply to normal caliber ureters and in infancy, while antireflux operation may be considered at diagnosis in dilated ureters, bilateral reflux or in the presence of renal lesions.

The ureteric orifice: The embryologic key to radiologic status of duplex kidneys

Abstract In this study the ureteric orifice position of duplex ureters in the bladder or urethra of children was correlated with the kidney configuration as determined by x-ray examination and in some by surgical excision and biopsy. A previous study 1 of 51 necropsy speciments of duplex kidneys, ureters, and bladders of neonates, revealed a close correlation between ureteric oreteric orifice position and kidney morphology. This clinical study of children further confirms that the position and type of ureteral orifice act as guides to renal order and disorder in duplex kidneys. A radiographic classification of kidney configurrations was invoked to match and correlate form with orifice position. From this cystoradiographic study, it appears that renal abnormalities occur when ureteric buds arise from faulty locations in the Wolffian duct during embryogenesis.

CONGENITAL ANOMALIES OF THE KIDNEY AND URINARY TRACT— ROLE OF THE LOSS OF FUNCTION MUTATION IN THE PLURIPOTENT ANGIOTENSIN TYPE 2 RECEPTOR GENE

PURPOSEnRecent studies of the human genome and genetic engineering experiments in mice revealed that congenital anomalies of the kidney and urinary tract commonly seen in newborns in various anatomical forms are polygenic disease, that is a disease caused by simultaneous defects in multiple genes. We discuss some possible genetic explanations of the classic theories of the formation of congenital kidney and urinary tract anomalies.nnnMATERIALS AND METHODSnWe reviewed classic and current theories regarding urinary tract development. Included in our review are recent results from our laboratory evaluating the genetic role of normal and abnormal urinary tract development.nnnRESULTSnWe observed a genetic abnormality that may explain many classic anatomical theories of congenital kidney and urinary tract anomalies. One of the genes involved in urinary tract ontogenesis is the angiotensin type 2 receptor gene, which is the other angiotensin receptor. While the type 1 receptor mediates essentially all known actions of angiotensin, including its hypertensive effect, relatively little is known about the angiotensin type 2 receptor. Careful dissection studies in mutant mouse embryos selectively lacking the angiotensin type 2 receptor gene revealed that this gene is pleiotropic, that is its defect causes not only ectopic ureteral budding from the wolffian duct, but also disturbance in other subsequent ontogenic events that are critical for the normal growth of the kidney and urinary tract.nnnCONCLUSIONSnMany congenital anomalies of the kidney and urinary tract appear to share a common genetic cause. While these anomalies are caused by various genetic hits, abnormalities in the angiotensin type 2 receptor gene are often involved in this anomalous development. This review article offers a better understanding of the genetics involved in urinary tract development and ties some of the newly emerging genetic theories with classic anatomical theories.

Effects of external inguinoscrotal compression on descent of the testis in rats

Intrauterine compression of the developing genitalia by the feet in early fetal development may be a cause of delayed descent of the testes. The purpose of our experiments on neonatal rats was to determine whether compression on the inguinoscrotum would impair testicular descent, which normally occurs during the 1st postnatal month. Two methods of compressing the inguinoscrotal region on one side were used: firstly, a ribcage graft from an inbred littermate was inserted subcutaneously in one series, and secondly, skin tightening was created by excising a wide area superficial to the gubernaculum and stitching the skin edges together longitudinally. Descent of the testis was retarded on the compressed side compared with both the non-compressed side and the sham-operated animals. The testes that had retardation of descent were smaller than those of the opposite side and of the sham-operated rats. It was concluded that experimental compression in rats may be akin to focal intrauterine compression in the human, causing delayed descent and changes in dimensions of the testes.

Covered anus with anocutaneous fistula: The muscular sphincters

A rare specimen of a covered anus with anocutaneous fistula obtained from a newborn female baby was subjected to macroexamination and microexamination to determine the anatomy of the sphincters and the levatores musculature. The internal sphincter and the deep voluntary sphincters, albeit slightly modified, were well developed but the sphincters in the perineum were absent or rudimentary. The pelvic muscles were present even in the absence of the sacrum up to and including the second sacral vertebra.

Urethro‐Vaginal Malformations

The junction between the interior of the genital tract and the exterior is the vagina, which is prone to distortion by Mullerian malformations. Genital duct deformities, such as absence of the vagina, didelphys or septa1 partition, and hymen defects, are intrinsic in the Mullerian system and are well documented (Patten, 1947). They may occur alone or may be superimposed on urogenital or urorectogenital deformities.

CONGENITAL RECTAL FISTULAE AND THEIR SPHINCTERS

The degree of success of surgical reconstruction of the rectum depends on the efficiency of the ultimate sphincteric control. The levator ani muscles have the dual function of sphincter and sense organ of the new anal canal.

Embryogenesis of the hymen and caudal end of the vagina deduced from uterovaginal anomalies

The morphogenesis of the caudal end of the vagina and hymen is controversial amongst embryologists. The urogenital sinus alone or in combination with the müllerian ducts, the wolffian ducts, or all three have been claimed to be the precursors of these organs. We describe two examples of imperforate hymen in one unit of a duplex vagina associated with ipsilateral ureterorenal anomalies that lend light to the controversy. The imperforate hymen occurred on the same side as the ureteric anomaly, indicating that the combined anomaly is derived from a deficit in a common denominator, the ipsilateral wolffian duct. The migration of the wolffian duct stopped short of the urogenital sinus, affected the development of the ureteric bud, and led to defective canalisation of the vaginal plate and the imperforate hymen. By inference, normal hymen formation is also mediated by the wolffian duct and is derived from the vaginal bulbs of urogenital sinus origin externally and the müllerian ducts internally; the vagina is also of müllerian origin. Once the normal hymen perforates, there may be intermingling of the sinus and ductal epithelia.