Chronic pyelonephritis is observed in 35% of urological patients.
Morphology. This disease is characterized by foci and polymorphism of the inflammatory process in the kidney. There are 4 stages of development of chronic pyelonephritis, in which there is a rapid and pronounced lesion of the tubules compared to the glomeruli. In stage I, the glomeruli are intact, there is a uniform atrophy of the collecting tubules and diffuse leukocyte infiltration of interstitial tissue. In stage II, hyalinization of individual glomeruli occurs, atrophy of the tubules is expressed to an even greater extent, there is a decrease in inflammatory infiltration of the interstitial and the growth of connective tissue. In stage III, many glomeruli die, most of the tubules are sharply expanded; in stage IV, most of the glomeruli of the tubules die, the kidney decreases in size, is replaced by scar tissue. The outcome of chronic pyelonephritis depends on the presence and degree of violation of the outflow of urine from the renal pelvis: with normal passage of urine, nephrosclerosis (shrunken kidney) develops, with stasis of urine-pionephrosis. With bilateral chronic pyelonephritis or damage to a single kidney in the end stage, chronic renal failure develops. In 7-38% of patients with chronic pyelonephritis, nephrogenic hypertension develops. Depending on the degree of activity of the inflammatory process in the kidney in chronic pyelonephritis, the active phase of inflammation, the latent phase and the remission phase are distinguished. Variants of the course of chronic pyelonephritis: latent pyelonephritis, recurrent, anemic, hypertensive, azotemic.
The clinic. Chronic pyelonephritis is characterized by a paucity of general clinical symptoms due to the slow, sluggish course of the inflammatory process in the interstitial kidney tissue. The disease is usually detected a few years after cystitis or other acute process in the urinary tract with a random examination of urine or during an examination for urolithiasis, arterial hypertension, kidney failure. Common symptoms of chronic pyelonephritis: subfebrile fever, general weakness, rapid fatigue, lack of appetite, nausea, vomiting, anemia, discoloration, dry skin, arterial hypertension. Local symptoms: lower back pain, impaired urination (polyuria or oliguria) and urination (dysuria, pollakiuria, etc.), changes in urine tests: leukocyturia, bacteriuria, proteinuria, hematuria. In secondary chronic pyelonephritis, local signs are often expressed, due to concomitant or main urological disease (pain in the corresponding half of the lower back of a nagging or paroxysmal nature). With bilateral chronic pyelonephritis, various signs of chronic kidney failure appear.
Diagnostics. Of great importance is the detection of bacteriuria and leukocyturia, the detection of Sternheimer—Malbin cells and active white blood cells in the urine sediment. Latent leukocyturia is detected by provocative tests (prednisolone, pyrogenal).
Immunological methods for the diagnosis of chronic pyelonephritis are used, based on the detection of autoantibodies to renal antigens using the complement binding reaction and the passive hemagglutination reaction. The titers of anti-renal antibodies increase with the exacerbation of chronic pyelonephritis. For the diagnosis of chronic pyelonephritis and the determination of the activity of the process, the titer of antibacterial antibodies is important, which in the phase of active inflammation is greater than 1 : 160. In patients with chronic pyelonephritis, there is a more pronounced violation of tubular reabsorption compared to glomerular filtration according to clearance tests; violation or absence of indigocarmine release during chromocystoscopy. The vertical position of the kidney, as well as the increase in its size and the irregularity of the contours are found on the overview urogram, tomograms or zonograms of the urinary tract. Excretory urography, in addition to changes in the size of the kidneys and their contours, allows you to determine the deformation of the calyx and pelvis, a violation of the tone of the upper urinary tract. On excretory urograms in the initial stages of chronic pyelonephritis, there is a decrease in the concentration and a delayed release of radiopaque substance by the affected kidney. In the later stages of the disease, there is a deformation of the calyxes: they become rounded, with flattened papillae and narrowed necks.
According to angiographic signs, there are 3 stages of chronic pyelonephritis.
Stage I is characterized by a decrease in the number of small branches of segmental arteries to their complete disappearance; large segmental arteries are short, conically narrowed to the periphery, almost have no branches, this phenomenon is called the “burnt tree”symptom.
Stage II of chronic pyelonephritis is characterized by diffuse narrowing of the arterial bed of the entire kidney, small branches of the interlobar arteries are absent. The nephrogram has uneven contours, the cortical substance is inhomogeneous, its size is reduced.
In stage III, there is a sharp narrowing of all the vessels of the kidney, their deformation and a decrease in the number. The size of the kidney is significantly reduced, the contours are uneven – a shriveled kidney.
The method of thermography notes an increase in temperature in the lumbosacral region in the presence of active chronic pyelonephritis. Isotope renography allows you to determine the functional state of the kidneys, their blood supply, and tubular functions. Scanning makes it possible to obtain an image of the size and contours of the kidneys, to identify large-focal defects in the accumulation of radioisotope substances in the renal tissue. Dynamic kidney scintigraphy also reveals small foci of pyelonephritis in the form of a decrease in the accumulation of activity, slowing the excretion of the isotope. Sometimes a kidney biopsy is performed.
Differential diagnosis is performed with chronic glomerulonephritis, amyloidosis of the kidneys, glomerulosclerosis, tuberculosis of the kidney, necrotic papillitis, spongy kidney, interstitial nephritis, nephrosclerosis, hypoplasia of the kidney, multicystic kidney.
Treatment. Elimination of the source of infection in the body: chronic tonsillitis, carious teeth, furunculosis, chronic constipation. In case of violation of the passage of urine, its outflow from the kidney is restored. With unilateral chronic pyelonephritis that does not respond to therapy, or pyelonephrotic shrinking of one kidney, complicated by arterial hypertension, nephrectomy is indicated. Long-term antibacterial treatment is carried out with intermittent courses in accordance with the nature of the microflora. Antibiotics are alternated with the intake of sulfonamides, chemotherapy drugs, and nitrofuran derivatives. At the same time, it is necessary to prescribe a plentiful alkaline drink to prevent the crystallization of drugs in the tubules. Sequential or combined administration of antimicrobial drugs for 1.5-2 months, as a rule, allows to achieve clinical and laboratory remission in most patients with chronic pyelonephritis. During the next 3-6 months after remission, intermittent maintenance therapy with antibacterial drugs is used (10-day courses 1 time per month). In the intervals between these cycles, herbal treatment is prescribed. With persistent long-term remission of chronic pyelonephritis (after 3-6 months of maintenance therapy), antibacterial agents are not prescribed.
Within a year after acute pyelonephritis and at least 5 years after exacerbation of chronic pyelonephritis, anti-relapse therapy is carried out: the first 7-10 days of each month, taking a uroseptic (1 time per night in 1/4 of the daily dose). The next 20 days-collecting herbs (diuretics, litolytics, antiseptics, anti-inflammatory, strengthening the vascular wall, improving the vitamin composition of the body). Fees are set for 3-6 months. Physiotherapy procedures of anti-inflammatory and resorption action are also used. In some cases, the issues of surgical correction of urinary tract abnormalities are solved. Patients with chronic pyelonephritis should consume a sufficient amount of liquid and table salt. The diet excludes foods rich in extractive substances: spices, marinades, smoked meats, sausages, canned food, spices.
The prognosis depends on the primary or secondary nature of the lesion, the intensity of treatment, and concomitant diseases. Treatment of primary acute pyelonephritis occurs in 40-60%, primary chronic-25-35%. The result of timely diagnosis of chronic pyelonephritis, long-term and persistent treatment can be the cure of the patient and complete restoration of working capacity. Heavy physical work, cooling, dampness, and contact with nephrotoxic substances are contraindicated. With renal failure and severe hypertension, patients are transferred to disability.
Dispensary observation is constant.