Carbuncle of the kidney

Renal carbuncle is a purulent-necrotic lesion with the formation of a limited infiltrate in the renal cortex.

The incidence of renal carbuncle has increased significantly in recent years.

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Causes carbuncle of the kidney

Renal carbuncle is either a form of purulent pyelonephritis or occurs as a result of hematogenous penetration of infection into the renal cortex in the presence of any purulent foci in the body. Renal carbuncle is often preceded by upper respiratory tract diseases, pustular skin lesions, furunculosis, carbuncle, panaritium, mastitis, peritonsillar abscess, etc. By the time the kidney is affected, patients often forget about the primary purulent focus. Healthy kidneys are usually involved in the process. Carbuncle may occur due to impaired urine passage due to obstruction of the ureter by a calculus, bladder cancer and urethral cancer, prostate adenoma, pregnancy, urethral stricture. Ovarian and uterine cancer.

There are various mechanisms for the formation of a renal carbuncle:

• a septic embolus enters the renal artery, causing a septic renal infarction and carbuncle;
• a branch of the renal artery may not be completely occluded by an embolus, but in which a further spreading infection develops;
• The infection is localized in one place, from which it spreads to the kidney tissue, causing necrosis and suppuration.

Therefore, a large microbial embolus blocking a large renal vessel is not necessary for a carbuncle to form. An inflammatory process occurs in the area surrounding the affected area, with the formation of a granulation protective ridge. The infiltrate extends to the area of the calyces or renal pelvis. Reactive edema develops in the perirenal tissue, followed by purulent inflammation, often with the formation of a paranephric abscess. The inflammation may not melt for a long time, as a result of which the renal tissue, dead due to an extensive infarction with infiltration around the circumference, is saturated with pus. The same picture develops as with a carbuncle of the skin. This is what gave Israel (1881) the basis to call the described lesion a renal carbuncle. A renal carbuncle has different sizes - from a lentil grain to a chicken egg.

The most common pathogens of renal carbuncles are gram-negative (E. coli, Proteus, Pseudomonas aeruginosa) and mixed flora. After the infected contents of the convoluted tubules of the second order break through into the connective tissue of the kidney, inflammation of the interstitial tissue begins. The process is of a pronounced focal nature. Leukocyte infiltrates and the formation of leukocyte "muffs" around the collecting tubules can be seen in the connective tissue of the kidney. A large number of microorganisms are determined in the lumens of the tubules and capsules of the glomeruli, which indicates ongoing aggression. With timely assistance, the inflammatory process can subside. If the inflammation is not treated, inflammatory infiltration of the walls occurs in the intraorgan arteries passing through the foci of inflammation, elastophyrosis occurs, causing thrombosis of the arterioles with complete cessation of blood flow. As a result, the area of the kidney supplied by the affected artery is subject to acute ischemia, even to the point of infarction.

In the normal course of acute pyelonephritis, the ischemic (necrotic) area shrinks, and one of the retractile scars appears in the renal parenchyma.

However, another course is possible, leading directly to the development of a kidney carbuncle. At this stage, superinfection of the ischemic (necrotic) area of the kidney occurs. Bacteria that have entered necrotic or sharply ischemic tissues receive favorable conditions for reproduction.

The beginning of the purulent-necrotic process leads to the formation of a cone-shaped (repeating the structure of the ischemic zone of the kidney), delimited from the surrounding renal tissue area of purulent-necrotic decay of the carbuncle.

Significant importance in the etiology of carbuncle is given to the causative agents of necrotizing inflammation. Penetrating into sharply ischemic tissue, Proteus and Pseudomonas aeruginosa cause its final purulent-necrotic decay.

According to literature data, renal carbuncle is localized on the right side twice as often (mainly in the upper segment). The inflammatory process in 95% of patients develops in one kidney, but can also be bilateral. Sometimes multiple carbuncles are found in one kidney.

In 84% of patients, renal carbuncle occurs against the background of various concomitant diseases that weaken the body's defenses (diabetes mellitus, coronary heart disease (CHD), cardiosclerosis, widespread atherosclerosis, chronic cholecystopancreatitis, chronic inflammation of the internal genital organs in women, etc.)

The combination of renal carbuncle and apostematous pyelonephritis is observed in 38% of patients.

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Symptoms carbuncle of the kidney

The disease can proceed latently and rapidly, with typical symptoms of a kidney carbuncle. The most constant symptoms of a kidney carbuncle are chills, high body temperature, nausea, vomiting, fatigue, and loss of appetite. Expressed local symptoms occur early: dull, aching pain in the lumbar region, tenderness on palpation, a positive Pasternatsky's sign, often an enlarged kidney. Symptoms of a kidney carbuncle depend on the severity of the inflammatory process, its localization, stage of the disease, complications of the urinary tract, kidney function, and the presence of concomitant diseases. If the carbuncle is in the upper segment of the kidney, the infection can spread through the lymphatic ducts and move to the pleura.

Irritation of the posterior leaflet of the parietal peritoneum is accompanied by signs that can simulate the clinical picture of acute abdomen. If the carbuncle is localized in the upper segment of the kidney, the inflammatory infiltrate can spread to the adrenal gland, causing adrenal hypofunction syndrome. Pain, tension, and swelling in the lumbar region are late signs of the disease. All patients have an elevated white blood cell count (10-20x109/l). In patients with primary carbuncle, urine is sterile in the early stages of the disease. Moderate pyuria appears later. Typical symptoms of renal carbuncle are rare. Erased and atypical forms of renal carbuncle occur without hyperthermia and pain; without changes in the hemogram or with changes that are not characteristic of acute inflammatory processes; without changes in the composition of urine or with atypical disorders; with a prevalence of symptoms of general disorders and previous diseases or conditions. In many patients, renal carbuncle occurs under different masks: cardiovascular, abdominal, gastrointestinal, pulmonary, neuropsychomorphic, nephro- and hepatopathic, thromboembolic diseases.

In case of renal carbuncle, which proceeds according to the type of cardiovascular diseases, the symptoms of damage to the cardiovascular system come to the fore. Thus, with a general tendency to tachycardia and arterial hypotension, an increase in arterial pressure and bradycardia are possible. Symptoms of acute myocardial dystrophy and right ventricular failure are expressed.

There are focal disturbances of myocardial blood supply, intracardiac conduction, and peripheral edema of the circulatory type is possible. This is mainly observed in elderly and senile people. They are usually admitted to therapeutic or cardiology departments with a diagnosis of "acute heart failure", "myocardial infarction", etc. Often, the final diagnosis is established only during an autopsy.

Patients with "abdominal" clinical manifestations complain mainly of acute diffuse or localized abdominal pain. Vomiting is common, peritoneal symptoms are expressed. Often such patients are first admitted to general surgical departments.

In patients with gastrointestinal manifestations, the disease carbuncle of the kidney begins with pain in the epigastric region. Frequent painful defecation is noted, accompanied by nausea and vomiting. The feces contain blood and mucus. Such patients are often hospitalized in infectious disease departments with a diagnosis of "acute dysentery".

With late diagnosis and inadequate treatment, pneumonia, pulmonary insufficiency, and pulmonary edema are often observed as a result of hematogenous toxic-septic lung damage. Sometimes pulmonary symptoms can acquire independent significance, causing incorrect diagnosis and treatment tactics.

Neuropsychomorphic symptoms are possible. In such patients, symptoms of motor excitation, delirium, tonic and clonic seizures, and symptoms of brainstem disorders predominate. Only a qualified analysis of neurological symptoms allows us to establish their secondary (intoxication) genesis.

Sometimes, with weak local symptoms and without changes in the composition of urine, symptoms of severe liver damage come to the fore - acute jaundice, enlarged liver. Severe toxic-septic liver damage is observed in elderly and weakened patients with multiple and bilateral renal carbuncles. In them, symptoms of acute renal failure or hepatorenal failure sometimes come to the fore.

Sometimes septic thromboembolism of the pulmonary artery or brain occurs. Usually these patients die. Renal carbuncle is found only at autopsy.

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Diagnostics carbuncle of the kidney

Diagnosis of renal carbuncle is difficult, since there are no pathognomonic clinical signs. In most cases, the diagnosis is made presumptively based on the acute, septic onset of the disease, the presence of local pain, and X-ray and ultrasound data.

Often, patients are initially diagnosed with bronchopneumonia, kidney tumor, cholecystitis, pancreatitis, appendicitis, urolithiasis, pyonephrosis, acute pyelonephritis. In the case of a single primary renal carbuncle, the urine is normal or changes are found in it that are common for acute inflammatory processes of the urinary system (proteinuria, leukocyturia, bacteriuria, microhematuria). Changes characteristic of a nonspecific inflammatory process are noted in the blood - high leukocytosis, increased ESR, hypochromic anemia, hypoproteinemia. The diagnosis is facilitated by communication of the abscess with the renal pelvis and calyces, since this causes massive leukocyturia.

The greatest difficulties are observed in those cases when the abscess is located in the renal cortex and the patency of the upper urinary tract is not impaired.

The most objective diagnostic methods are considered to be radionuclide scanning of the kidneys, ultrasonography and CT.

On a general radiograph, one can detect an increase in the size of one of the kidney segments, the disappearance of the lumbar muscle contour on the affected side, and shadows of urinary stones. Indirect signs include a decrease in the respiratory excursion of the diaphragm and, sometimes, effusion in the diaphragmatic sinus.

Excretory urography reveals decreased function of the corresponding kidney in 6% of patients. Deformation and narrowing of the renal pelvis are visible, and in some patients, displacement and erasure of the contour of the calyces. Sometimes signs characteristic of a kidney tumor are revealed on an X-ray. On CT scans, a kidney carbuncle appears as an area equal in density to the surrounding tissue or having increased transparency. On a spiral CT scan with contrast, areas of heterogeneous structure are determined, in which there is no accumulation of contrast agent, surrounded by a rim of increased density along the periphery. When conducting an ultrasound, the following signs of a kidney carbuncle are distinguished:

• increase in the thickness of the cortical layer in the area of carbuncle formation;
• unevenness and bulging of the kidney contour at the site of carbuncle formation;
• thickening of the walls of the renal pelvis, cortex and medulla;
• decreased renal excursion.

Dopplerography examination reveals a significant depletion of the vascular pattern in the lesion or an avascular zone around the forming carbuncle.

Renal carbuncle must be differentiated from infectious processes. Renal parenchyma tumors, suppurating solitary renal cyst, acute cholecystitis, subdiaphragmatic abscess, pancreatitis, renal tuberculosis. In unclear situations, CT of the kidney helps to conduct differential diagnostics.

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Treatment carbuncle of the kidney

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Surgical treatment of renal carbuncle

An emergency operation is indicated. It begins with lumbotomy, release and examination of the kidney. The surgical intervention depends on the nature of the pathological changes, the general condition of the patient and the function of the opposite kidney. In most patients, the carbuncle is opened and drained. The carbuncle area is cut with a cross-shaped incision until fresh blood appears in the depth of the wound. In cases of destruction of a large area of the kidney or multiple lesions, a nephrectomy is performed.

Intensive antibacterial treatment of renal carbuncle as an independent method can be recommended only in the initial stage of the disease under active observation of a urologist.

A method of combined use of antibacterial therapy with the introduction of cryoprecipitate has been developed. Its introduction promotes an increase in the concentration of fibronectin in the blood, which in turn leads to the restoration of blood flow in the ischemic zone, penetration of antibacterial agents into the inflammation focus and gradual reverse development of the inflammatory process in the kidney.

This method of treatment in patients with carbuncle allows achieving positive clinical results in 84.1%. According to ultrasound data, blood flow in the carbuncle area is restored and signs of renal ischemia disappear.

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Prevention

Renal carbuncle can be prevented if acute pyelonephritis and purulent-inflammatory processes of various localizations are treated promptly and adequately. In patients with a single carbuncle and unimpaired urodynamics, the prognosis is favorable with timely surgical intervention. After surgery, patients need dispensary observation.

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