Hydronephrosis

Hydronephrosis develops as a result of impairment of urine outflow and is characterized by an expansion of the bowel-cup system, pathological changes in the interstitial tissue of the kidneys and atrophy of its parenchyma. Hydronephrosis of the right or left kidney occurs equally often, bilateral - only in 5-9% of cases of this disease.

Etiology, pathogenesis. Hydronephrosis can be congenital and acquired. The causes of congenital hydronephrosis are dystenesis of the urinary tract; Congenital anomaly of the location of the renal artery (or its branch), compressing the ureter; Congenital valves and strictures of the ureter; Retrocaval arrangement of the ureter; Ureterocele, congenital obstruction of the lower urinary tract. The causes of acquired hydronephrosis are certain urological diseases: renal stone disease, inflammatory changes in the urinary system, traumatic narrowing of the urinary tract, urinary tract tumors, prostate tumors, as well as retroperitoneal tissue, cervical tumors, malignant infiltration of retroperitoneal tissue and pelvic floor tissue, tumor metastases in Retroperitoneal lymph nodes, and, finally, various traumatic and other spinal cord injuries leading to disturbances in the outflow of urine. In those cases where the obstruction of the urine outflow is located distal to the pelvic-ureteral segment and not only the pelvis but also the ureter expands, hydroureteronephrosis takes place.

Hydronephrosis is aseptic and infected. In the first case, renal changes depend on the degree of obstruction and duration of the disease, in the second - both on the degree of obstruction and duration of the disease, and on the virulence of the infection. In the initial stages of the disease, the kidney is not much different from the healthy organ, only the enlargement of the pelvis and calyx is found. Increased intra-venous pressure disrupts kidney function, but these disorders are still reversible and after the removal of obstruction the kidney function is restored. With a longer disturbance of the outflow of urine in the kidney, organic changes develop that are considered as obstructive interstitial nephritis. In this case, after the removal of obstruction, the kidney function is only partially restored. If there is an infection of hydronephrosis, then interstitial nephritis passes into obstructive pyelonephritis.

Symptoms, course. Hydronephrosis can develop asymptomatically for a long time, and only complications such as infection, stone formation in the pelvis, or traumatic damage to the affected kidney, cause the first symptoms of the disease, which give the basis for the study of the urinary system. In most cases, hydronephrosis is manifested by pain in the lumbar region. The pains are of the nature of renal colic (see Renal colic) with typical localization and irradiation along the ureter in the groin, in the testicle in men and the external genitals in women, the thigh or the perineum.

Attacks of renal colic are more typical for the initial stage of hydronephrosis. Later, when the wall of the pelvis and calyx is partially replaced by the connective tissue, the pelvis and calyx lose the ability to actively contract, hydronephrosis is manifested by blunt pain in the lumbar region. Pain in hydronephrosis, as in nephrolithiasis, may occur during the day and at night, regardless of which side the patient is sleeping on. The last symptom is important for differential diagnosis of hydronephrosis with nephroptosis, in which patients prefer to sleep on the diseased side. With obstruction of the upper urinary tract, dysuria usually does not occur or it occurs only during an attack of pain. Another important symptom of hydronephrosis is hematuria. Macroscopic hematuria is observed in 20% of patients with hydronephrosis, microhematuria is much more frequent. Increasing the temperature during the intensification of pain in the lumbar region is evidence of infection. To probe the increased kidney it is possible only at very big hydronephrosis. A more informative method of research in hydronephrosis is chromoscystoscopy, in which there is a significant delay or absence of indigo carmine from the side of the affected kidney. X-ray examination of the kidney is the main method of diagnosing hydronephrosis.

An overview radiograph provides the opportunity to determine the size of the kidneys and to detect stones, if any. On a series of intravenous urograms, a slow accumulation of contrast solution in the enlarged pelvis (pelvis) and calyxes can be noted. On urograms, an enlarged, rounded pelvis, enlarged calyxes are seen. If the kidney function is significantly impaired, the contrast solution may accumulate in sufficient concentration only after 1 to 2 hours or not to stand out at all by a diseased kidney. Thus, intravenous urography allows to diagnose the stage of the disease from pyeloctasia to giant hydronephrosis with loss of kidney function. Additional diagnostic methods, which substantially refine the data of clinical and radiological methods, are radionuclide renography and kidney scanning, which establish the degree of impairment of renal function (kidneys).

Due to the similarity of symptoms, hydronephrosis should be differentiated from nephrolithiasis (not complicated by the development of hydronephrosis), in which only the kidney stone is radioliologically detected, from nephroptosis, in which the pain occurs during movement, patients prefer to sleep on the sore side, the displacing kidney is probed in the standing position, and On X-rays performed in a supine and standing position, significant mobility of the kidney is revealed. In kidney tumors, unlike hydronephrosis, the palpable kidney is dense and tuberous. In polycystic kidney buds are probed on both sides.

In all these cases, the radiologic methods of research play the leading role in differential diagnosis.

Treatment of hydronephrosis is surgical. It is important to conduct it in the early period, when the elimination of urinary tract obstruction not only prevents further anatomical changes, but also leads to an improvement in kidney function. In the treatment of infected hydronephrosis, antibacterial therapy under the control of urine cultures and the study of microflora for sensitivity to antibacterial drugs take an important place (see Pyelonephritis).

Forecast. Bilateral hydronephrosis with increasing residual nitrogen in the blood and other violations of homeostasis leads to chronic renal failure.