Urogenital disorders

I./4.2.: Double ureter and double renal pelvis, ureterolithiasis, megaloureter (ureterectasia) and partial hydronephrosis

I./4.2.1.: Epidemiology, etiology

Malformations of the upper urinary tract, the draining system of urine are frequent; their cause is unknown, and they have several degrees. In the mildest causes only the renal pelvis is divided or doubled, but these continue in a single ureter. When the ureter is also divided in part or all along, it is called a split or duplex ureter. In the latter case the two ureters cross each other, because the ureter which belongs to the upper part of the kidney opens into the urinary bladder at a lower place (Weigert-Meyer rule).

In females sometimes the ureter belonging to the upper part of the kidney has an ectopic opening to the perineum or into the vagina, creating a continuous dripping of urine by this way. A disordered transport occurs generally in the ureter belonging to the upper pole, and a dilatation develops in the upper part of the kidney and frequently in the associated ureter. If the dilatation is not treated timely, it makes susceptible to inflammation and the formation of renal stones due to the stagnating urine, and through the increased intrapelvic pressure it leads to an irreversible damage of the renal parenchyma as well as impaired transport function of the ureter.

I./4.2.2.: Symptomatology

Double renal pelvis and double ureter are often asymptomatic and they are detected only in the adult age during an examination due to other causes. If the double renal pelvis is associated with a disorder of transport, the urine which cannot be drained and is stagnating in the kidney at a high pressure may result in dilatation, nephrolithiasis, inflammation and impairment of the renal parenchyma. These may cause renal colic, dull pain in the kidney area that is independent of the body’s posture; fever, frequent urge to void and a burning sensation in the urethra experienced during voiding of the urine. In infants their diagnosis is difficult, genitourinary malformations should be thought of in an infant with a fever of unknown cause, poor general condition, weight loss, feeding difficulty, loss of appetite.

I./4.2.3.: Diagnostics

I./4.2.3.1.: History

Other known congenital anomalies, previous diseases and the above listed symptoms should be checked during its taking.

I./4.2.3.2.: Physical examination

Tenderness of the costal-lumbar ankle or tenderness on pressure of the corresponding abdominal half may be found during this. An extremely dilated, hydronephrotic kidney may be palpated and felt by ballottement in lean patients, similarly to an abscessing process that developed on the base of a hydronephrotic kidney.

I./4.2.3.3.: Imaging

Abdominal ultrasound shows the pelvic dilatation, the formed renal stones, and the degree of parenchymal impairment as well. However, if a double pelvis is not associated with a disorder of urinary transport, and there is no dilatation, the ultrasound picture may at most suggest a double pelvis only by a more marked parenchymal bridge intruding to the kidney’s mass. Ureters can be examined by ultrasound only in lean patients with an obstruction, and even then with insufficient safety; nevertheless the obstruction of the ureter can clearly be deducted from the dilatation of the renal pelvis. Consequently from the above, ultrasound examination should be completed by other imaging examinations. Intravenous urography can perfectly depict the ureteropelvic system together with all of its anomalies.

Though CT examination with contrast agent is associated with a more significant radiation exposure, it provides information, in addition to the above, also on the neighboring organs. A shortcoming of the previous two examinations is that these can be performed only in case of a well functioning kidney and, as mentioned earlier, pelviureteral anomalies are often associated with a disorder of urinary transport and a consequent impairment of renal function. Therefore in such cases contrast media should be let into the pelviureteral hollow by another way, anterogradely through an external tube inserted to the kidney, a so called nephrostoma, or retrogradely by filling the hollows with contrast agent through a ureter catheter from the urinary bladder. The applicability of the above two examining procedures is limited by their invasive nature (and potential complications). If the patient has hypersensitivity to contrast media or she is pregnant, the above examinations are not allowed to be performed; in such cases magnetic resonance imaging (MRI) may help to examine the ureters.

Renal function can be measured exactly by radioisotope techniques: its dynamics are shown by MAG3 examination, while DMSA examination is helpful by providing an exact value of renal function. Prior to reconstructive surgery it is important to know the functioning of the kidneys, for example in case of a severely damaged, non-functioning kidney no reconstructive surgery is needed; the non-functional kidney should be removed. Nevertheless, if the function of the contralateral kidney is also impaired, one has to aspire to an organ-preserving surgical solution.

I./4.2.3.4.: Laboratory tests

In patients with bilateral renal impairment poor renal function parameters (azotemia), in those with an inflammation a shift of the differential count to the left, high WBC count, accelerated ESR, elevated CRP and procalcitonin values are characteristic. Pyuria is frequently seen in the urinary sediment, and microbiologic culturing of the urine provides a positive result. In patients with a suspected inflammation (pain affecting the kidney area, stinging sensation during voiding, frequent urge to urinate, voiding of small amounts, possibly prostration, fever and septic signs and symptoms) examination of the urinary sediment is recommended; the diagnosis is confirmed by the presence of pyuria.

It should be noted that a lack of pyuria does not exclude the possibility of pyelitis, i.e. in case of a closed, stagnating kidney the urine in the bladder may be clear; the inflammation is in progress only in the renal pelvis. It is mandatory to start urinary sample taking for culture and a blood culture in patients with high fever and chills, as a targeted therapy is based on the results of these. In patients with a suspected stone (renal colic, nausea, vomiting, frequent urge to void, hematuria, etc.), in addition to the US examination, it is useful to perform X-ray or CT examination with contrast media: these show the location and size of the stone and a possible malformation (e.g. stenosis) is also shown; the treatment can be planned on this base.

I./4.2.4.: Differential diagnosis

As mentioned earlier, congenital malformations of the kidney and ureter alone usually cause no complaint, only the pathologic states developing as their consequences (e.g.: inflammation, lithiasis, renal impairment) call the attention to themselves. During the assessment of these, congenital anatomic and functional disorders are revealed as the underlying causes of lithiasis, inflammation or renal impairment. The above pathologic states should therefore be differentiated from primary urolithiasis, inflammation, impaired renal function, etc., where no developmental anatomic and functional alterations are present.

Thus, if a patient presents himself/herself with the above complaints, the routine performance of ultrasound and urinary sediment examination, in addition to the physical examination, is essential for making a diagnosis. These are non-invasive, and they are usually sufficient for establishing a diagnosis, however if the suspicion of a malformation emerges, the assessment should be continued with an imaging with contrast agent (intravenous urography or retrograde ureterography, CT). It is important that not only anatomic, but also functional abnormities should be revealed during this.

Differentiation between a dilated ureteropelvic cavity that developed in consequence of disordered ureteric transport or lithiasis of the upper urinary tract and the rare congenital anomalies, where the renal cavities (e.g.: megacalycosis) or the ureter (e.g.: megaureter) are primarily wider may pose a problem. It is an important difference that in the first cases a secondary dilatation is present which is associated with an increased intrapelvic pressure and subsequent parenchymal impairment, making a surgical intervention necessary. In contrast to this, in the latter cases the dilatation is due not to an increased pressure but to a congenital anomaly in the wall of the upper system of cavities so that these are usually not associated with any loss of function or parenchymal impairment, and thus they require no surgery.

I./4.2.5.: Therapy

Dual renal pelvis, partly or completely doubled ureter alone require no treatment, regular follow up of patients (physical examination, US, urinary sediment, imaging examinations with contrast media if needed) is sufficient. However, if the double cavity system is presenting with a disorder of urinary passage, stagnation and subsequent inflammation, stone formation and parenchymal impairment, the therapy should include, in addition to removal of the stone and cessation of the inflammation, also the termination of the underlying cause.

In case of an inflammation broad spectrum antibiotic therapy (cephalosporins, fluoroquinolones, etc.) should be started and it may be switched to a targeted therapy based on the antibiogram. If the patient has pyuria, fever and pyelectasia, it is mandatory to divert the urine in order to prevent urosepsis (or to terminate it if it has already developed). The most recommended way of urinary diversion is the creation of a nephrostoma, where the stagnating, high-pressure, infected urine is drained through a tube inserted to the dilated renal cavity through the skin. Another possibility is to place a ureteric splint or double J splint into the ureter with the help of a cystoscope, and let down the stagnating urine that way. This later method, although it seems to be less invasive, does not ensure an unhindered outflow of the urine and low pressure of the renal pelvis in a certain and controlled way; however in severe cases (urosepsis) the life of the patient may depend on these.

In case of stones smaller then 5 mm, if these are not associated with a narrowing of the urinary tract, inflammation, fever, renal failure, and the patient’s complaints are bearable at a conservative therapy; while administering spasmolytics, one may wait for a spontaneous passing of the stone. The patient can promote it by consuming plenty of fluid and exercising. If the stone is larger than that or its passing is not to be expected e.g. because of a stricture, it can be crashed by extracorporeal shock wave lithotripsy (ESWL) so that the smaller fragments can spontaneously be voided. The harder, larger ureteroliths and nephroliths can be approached with a ureterorenoscope through the urethra or with a nephroscope through the skin, respectively, and then fragmented by laser, ultrasound or other source of energy, and their fragments can be removed.

However the underlying cause, malformation that led to the development of inflammation or stone does not cease to exist with the treatment of these. The surgical reparation of the anatomic abnormity and by this way the restoration of the function assures that the lithiasis or inflammation will not return and the function of the kidney will undergo no further deterioration. The treatment is primarily surgical, the decayed (usually upper) part of the kidney with dual renal pelvis is surgically removed together with its ureter (heminephrectomy, pole resection); in case of a stricture of the pyelo-ureteral transition or the ureter the narrowed segment is excised and the ends are reunited. In case of a decayed, non-functioning kidney only its removal is to be considered.