Ruptured kidney

Violation of anatomical integrity - rupture of the kidney - with partial or complete dysfunction of this most important internal organ is a life-threatening condition.

Epidemiology

According to statistics, kidney damage is accompanied by at least 10% of all significant abdominal injuries, and the prevalence of their rupture is 3-3.25%. In 90-95% of cases, renal injury is closed blunt, and its most common cause (over 60%) is a car accident.

This is followed by rupture of the kidney in catatrauma (43%) and as a result of various sports injuries (11%).

According to foreign sources, kidney rupture in children in 30% of cases occurs due to an accident (in 13% - as pedestrians); in 28% - due to blunt trauma when falling while cycling; in 8% - for falls and bruises on playgrounds and sports grounds.

Causes ruptured kidney

The most common causes of kidney damage leading to its rupture are associated with a closed injury, including sports: a kidney rupture can occur from a blow (direct blunt) to the upper abdomen, lateral, middle or lower back, lower chest; from impact during catatrauma (falling from a height); from hypercompression in an accident, etc.

Trauma can be penetrating from a stab or gunshot wound with profuse bleeding, causing death by ruptured kidney or fatal damage to other parenchymal organs.[1]

Iatrogenic causes include complications from surgery and procedures such as kidney biopsy and shock wave lithotripsy (crushing kidney stones).

Atraumatic spontaneous or spontaneous rupture of the kidney is rare, and, as experts say, it can be provoked by rupture of any neoplasm in the kidney, for example, progressive malignant hypernephroma,  renal angiolipoma  (benign mesenchymal tumor),  [2]as well as rupture of the kidney cyst accompanied by hemorrhage  . [3]

Risk factors

Factors that are partially responsible for the increased risk of kidney rupture are:

• childhood (due to the lower location of the kidneys relative to the ribs and the small volume of adipose tissue surrounding the kidney);
• abnormalities in the development of the kidneys ;
• violation of the position of the organ -  nephroptosis (prolapse of the kidney) ;
• the presence of neoplasms in the kidneys;
• pathological changes associated with a large single cyst and  polycystic kidney disease ; [4], [5]
• a number of diseases and congenital syndromes with complications in the form of  renal hydronephrosis ;
• urolithiasis leading to obstruction of the urinary tract;
• aneurysm of the arteries of the kidney;
• autoimmune diseases of the connective tissue. [6]

Pathogenesis

The ribs, abdominal and back muscles, as well as the supporting fascia system and the surrounding adipose tissue, protect the kidneys well. But at the same time, their lower poles are located below the XII ribs, and this is the most vulnerable area of the kidneys when struck or dropped.

The pathophysiology of the bursting action in such injuries consists in the compression and displacement of the organ, as well as the forces of deceleration and acceleration. They act in different ways, for example, acceleration forces can cause the kidney to move and "collide" with the ribs or transverse processes of the vertebrae (T12-L3). The compressive effect when the kidney is compressed is due to a sharp increase in pressure - intraluminal and in the urine accumulation system. [7]

And with a tumor, cyst, stones or hydronephrosis, partial atrophy of the cortex and destructive changes in the renal parenchyma, thinning of the walls of the renal capsule and its stretching are noted.

Symptoms ruptured kidney

The first signs of a ruptured kidney are manifested by  hematuria  (the presence of blood in the urine) and constant back pain - in the lumbar region - with tension in the lumbar muscles. The pain is localized on the right if there is a rupture of the right kidney, on the left - a rupture of the left kidney. And its intensity depends on the degree of violation of the integrity of the organ.

In addition, symptoms appear in the form of progressive edema (swelling) in the lumbar region (due to perirenal hemorrhage and hematoma in the retroperitoneal space); lowering blood pressure; general weakness and dizziness; cold sweat and pallor of the skin; nausea and vomiting; fever; decrease or complete cessation of urine output. [8]

Where does urine go when a kidney ruptures? Due to a violation of the integrity of the renal pelvis and / or cups, urine (extravasation) flows out of the kidney and accumulates in the adjacent area (in the perirenal tissues) and in the retroperitoneal space. The ingress of urine into the perirenal adipose tissue leads to its inflammation with cell death (lipolysis) and their replacement by fibrous tissue. An encapsulated formation is formed in the form of a perirenal pseudocyst - urinoma, which can also cause pain and a feeling of pressure.

Tachycardia, pronounced cyanosis, blurred vision and confusion against the background of falling blood pressure indicate the development of a state of shock.

According to the localization of damage, experts identify such types of breaks as:

• rupture of the kidney capsule (capsula adiposa) - its thin fibrous membrane with partial damage to the cortical layer (and the formation of a perirenal hematoma);
• subcapsular rupture of the kidney - not affecting the structure of the urine storage system (calyx-pelvic complex) rupture of the kidney parenchyma, that is, its internal tissues;
• rupture of the parenchyma of the kidney with damage to its cups and pelvis, accompanied by thrombosis of a part of the renal artery;
• smashed (total) rupture of the kidney.

Complications and consequences

Kidney rupture can have complications and consequences in the form of:

• secondary arterial hemorrhage due to the formation of a pseudoaneurysm or arteriovenous fistula;
• the formation of a urinary or hemorrhagic cyst of the kidney;
• urinary fistula;
• inflammation of the perineal tissues, which can lead to abscess and pyelosepsis;
• focal cicatricial changes (fibrosis) of the parenchyma with the development of obstructive nephropathy and severe renal failure;
• post-traumatic hydronephrosis;
• ischemia of the kidney with nephrogenic hypertension;
• secondary pyelonephritis with  pyonephrosis ;
• the formation of calculi.

Diagnostics ruptured kidney

For both traumatic and spontaneous kidney ruptures, timely diagnosis based on organ imaging is very important.

Therefore, in the first place - instrumental diagnostics:  X-ray of the kidneys  and excretory urography; Ultrasound of the kidneys  and computed tomography (CT) with contrast. [9]

Conventional renal ultrasonography has certain limitations, since its sensitivity in such cases is not higher than 22%, and parenchymal lesions can be isoechoic. A rupture of the kidney on ultrasound shows heterogeneous echogenicity at the site of damage to the parenchyma, hematoma and accumulation of the fluid component outside the kidney - in the retroperitoneal space. However, ultrasound cannot accurately differentiate blood from urine.

But the sensitivity of contrast-enhanced ultrasound in detecting kidney damage has a sensitivity of 63-69% and a fairly high specificity (over 90%).

Today, in acute injuries of the kidney with its rupture, computed tomography (multispiral) provides more complete anatomical and physiological information.

Magnetic resonance imaging (MRI) of the kidneys is  done if there are multiple abdominal injuries or if there are contraindications for the administration of contrast media with CT.

Required tests: urinalysis and CBC.

Differential diagnosis

With the help of CT Differential diagnosis is carried out with injuries of other organs of the abdominal cavity, in particular, the spleen, pancreas and liver.

Treatment ruptured kidney

The tactics of treating a ruptured kidney is determined depending on the degree of organ damage and the patient's condition, including the level of  hematocrit .

Conservative treatment is carried out with minor damage to the parenchyma. It includes adherence to bed rest (for two to three weeks) with monitoring of vital signs and laboratory tests of urine and blood; intake of calcium chloride (oral and injection); IV administration of systemic antibiotics. Continued bleeding requires blood and plasma transfusions.

With a worsening of the general condition, and in cases of more prolonged hematuria, the behavior of angioembolization by X-ray occlusion  and drainage of the hematoma is effective , and with extravasation of urine - drainage of urinoma and, if necessary, endourological stenting. [10]

An initially high degree of kidney damage (determined upon admission of the patient), as well as hemodynamic instability and the presence of signs of internal bleeding are indications for urgent surgical intervention: an operation is performed to restore the kidney (by suturing the tears), surgical removal of the non-viable part of the kidney (resection), or when intact second kidney - nephrectomy (removal), the frequency of which, according to some sources, ranges from 3.5 to 9%. [11]

More information in the material -  Kidney injury and damage

Prevention

Measures to prevent ruptured kidney can be considered the prevention of injuries leading to a violation of the anatomical integrity of this organ, as well as the detection and treatment of diseases that increase the risk of kidney damage.

Forecast

In each case, the prognosis depends on the degree of kidney damage during its rupture and on the timely provision of adequate medical care.