Ectopic kidney is a congenital disorder of the topography of the kidney, in which the organ may be located low, displaced into the pelvic cavity, sacroiliac region, chest, etc. There may be pain in the lower back or abdomen, dysuric and digestive disorders, as well as urolithiasis, pyelonephritis, hydronephrosis. Pathology is diagnosed by ultrasound of the kidneys, excretory urography, angiography. Treatment is required with the development of complications. In inflammatory processes, antibacterial therapy is prescribed, with nephrolithiasis, stones are removed.
ICD 10
Q63.2 Ectopic kidney
Meaning
Ectopic kidney in clinical urology refers to congenital anomalies. Pathology accounts for about 2.8% of the total number of kidney malformations. One or another form of pathology occurs in 1 out of 800-1000 newborns. Disease of the right side occurs in the population more often than the left, and accounts for 58.3% of the total number of cases of this anomaly versus 33.1%, respectively. Bilateral ectopic kidney is observed in 8.4% of cases.
Causes
Ectopic kidney is the result of delayed movement and rotation of the kidney from the pelvic region to the lumbar region during embryogenesis. Initially, the fetal kidneys are laid in the pelvis and, as they develop, they move upwards, occupying their normal anatomical position in the lumbar region at the level of the XI-XII thoracic – I-III lumbar vertebrae on both sides of the spinal column. Under the influence of unfavorable conditions, the migration and rotation of the kidney may be disrupted; in this case, the child is born with abnormal kidney topography. Unlike nephroptosis, with disease, the kidney is fixed and lacks mobility.
Classification
The abnormal location of the kidneys can be bilateral or unilateral. If there is no displacement of the kidney to the opposite side, then they talk about homolateral form. Less common is a cross (heterolateral) anomaly characterized by the migration of one or two ectopic kidney to the opposite side.
According to the location of the kidney, several types are distinguished:
- lumbar
- pelvic
- iliac
- subdiaphragmatic (thoracic).
The classification is based on the level of divergence of the renal arteries from the aortic trunk, which normally should correspond to the I lumbar vertebra.
With lumbar form (66.8%), there is a divergence of the renal arteries in the area from the II-III lumbar vertebrae to the aortic bifurcation. In this case, the kidney is located slightly below the normal anatomical level. Usually, such a kidney is turned forward by the pelvis, palpated in the hypochondrium and can be mistaken for nephroptosis or a tumor.
Iliac form (11.9%) is characterized by the departure of an abnormal number of renal arteries from the common iliac and the location of the kidney in the iliac fossa. Palpationally, such a kidney is sometimes mistaken for an ovarian cyst or a volumetric formation of the abdominal cavity.
In the case of pelvic form (21.3%), the renal arteries branch off from the internal iliac, in connection with which the kidney is located between the rectum and the bladder in men or the rectum and uterus in women. The ureter in such a ectopic kidney is always shortened. A kidney displaced into the pelvic cavity may be mistaken for a hematometer, an inflammatory appendage with adnexitis, an ectopic pregnancy.
Subdiaphragmatic (thoracic, intra-thoracic) ectopic kidney is noted when the renal arteries depart at the level of the body of the XII thoracic vertebra. In this case, the kidney is located high, sometimes in the chest cavity. The vessels and ureter of the thoracic kidney are much longer than usual. Thoracic ectopic kidney can be mistaken for a cyst of the mediastinum or lung, a tumor formation, an abscess, a closed pleurisy.
Symptoms
The clinical picture is determined by the anatomical form of the anomaly. Lumbar ectopic kidney may be asymptomatic or manifest as minor dull pain in the lower back. With iliac form, abdominal and iliac pain are frequent complaints, which in women worsen during menstruation. Pain is associated with the pressure exerted by the ectopic kidney on the nerve plexuses and neighboring organs. In this regard, it is also possible to develop urodynamic disorders – difficulty in the outflow of urine. When squeezing any part of the intestine, flatulence, constipation, nausea, gastralgia, vomiting may occur.
Pelvic ectopic kidney is accompanied by pain in the rectum and appendages in women, algodismenorrhea, dyspareunia. Pain in the pelvic location of the kidney can sometimes simulate a clinic of acute surgical pathology. With compression of the bladder and rectum, constipation, frequent and painful urination are noted. Intra-thoracic ectopic kidney can provoke the appearance of pain behind the sternum, usually associated with eating. Thoracic form is often combined with congenital diaphragmatic hernia.
Complications
Pelvic form can cause pregnancy toxicosis and complicate the course of arbitrary labor. In addition, the growing uterus further displaces the ectopic kidney, causing characteristic clinical symptoms. Cross-ectopic kidney is often accompanied by the development of chronic renal failure, and in the case of narrowing of the renal vessels – persistent nephrogenic hypertension at a young age.
Diseaseare susceptible to the development of diseases (hydronephrosis, nephrolithiasis, pyelonephritis, tuberculosis), which is associated with the presence of additional renal vessels, obstructed urine outflow and urostasis. During various surgical interventions on the abdominal or thoracic cavity, an abnormally located kidney may be accidentally damaged. In this case, suturing of damaged vessels, parenchyma or pelvis of the kidney is required, and if it is impossible to preserve the organ, nephrectomy is performed.
Diagnostics
With iliac and lumbar form, the kidney can be palpated through the anterior abdominal wall. Pelvic form can be detected during rectal (in men) or bimanual gynecological (in women) examination. With a finger rectal or vaginal examination, the ectopic kidney is palpated in the form of a dense sedentary formation located next to the rectum or the posterior arch of the vagina.
Thoracic form is diagnosed during preventive fluorography or chest X-ray. Ectopic kidneyy is more often defined as a dense rounded shadow in the posterior mediastinum above the diaphragm. For the correct diagnosis of pathology and determination of the form of the disease, imaging urological methods are used – ultrasound of the kidneys, retrograde and excretory urography, radioisotope renography (scintigraphy), renal angiography, MRI of the kidneys.
Ultrasound of the kidneys allows you to determine the absence of a kidney in its anatomical place and differentiate ectopic kidney with nephroptosis. Excretory urography, as a rule, accurately reveals the abnormal localization of the kidney, the degree of its rotation and limited mobility. With a sharp decrease in kidney function, retrograde pyelography is performed. During renal angiography, the level of divergence of the renal arteries from the aortic trunk is determined. Differential diagnosis of the anomaly is carried out with nephroptosis, tumors of the kidney, intestines, appendages.
Treatment
The treatment of pathology is conservative, if possible, aimed at eliminating the infectious process, preventing the formation of concretions or their removal. In the case of pyelonephritis, a course of treatment is carried out with antibacterial drugs, sulfonamides, nitrofurans, agents that improve renal blood flow.
Ectopic kidney complicated by calculus or hydronephrosis may require surgical removal of kidney stones (pyelolithotomy, nephrolithotomy, nephrolithotripsy, etc.). Nephrectomy is indicated in the death of an abnormally located kidney. Surgical relocation of the kidney presents significant difficulties due to the loose type of blood supply and the small caliber of vessels.
Prognosis and prevention
Patients with diagnosed ectopic kidney are subject to the supervision of a urologist. Further prognosis is determined by the presence of complications – hydronephrosis, pyelonephritis, vasorenal hypertension, neoplasms. Pelvic ectopic kidney cannot be a contraindication for pregnancy, but it often causes complications leading to fetal death. Therefore, pregnant women with ectopic kidney should be monitored by an obstetrician-gynecologist and urologist from an early date. Preventive measures have not been developed.