Dystopia of the kidney

Dystopia of the kidney is a congenital abnormal condition (2.8% of all renal anomalies).

[1], [2], [3], [4], [5], [6],

Causes of the kidney dystopia

The causes of kidney dystopia are the violation of embryonic migration and the rotation of the organ from the pelvis into the lumbar region. The process of turning by 90% begins already after the kidney has risen above the aortic bifurcation, so the termination of migration in the early stages is always combined with incomplete rotation. The lower the organ, the more disrupted its rotation process. In this case, the renal sinus and pelvis are facing forward or laterally. The process of turning the kidney may be incomplete, even when the organ is located in its place. Depending on the level at which the migration of the kidney has ceased upward, the pelvic, iliac and lumbar dystopia of the kidney are isolated.

Thoracic kidney dystopia is a special case that occurs with excessive organ migration into the chest cavity on the background of a congenital diaphragmatic hernia; on the left it occurs 2 times more often than on the right. Dystopia of the kidney can be one- and two-sided. Dystopy of the kidney without displacement to the opposite side is called homolateral. Much less often during migration to the lumbar region, the kidney is shifted to the opposite side, and then a cross (heterolateral) dystopia develops.

The structure of the renal vessels with kidney dystopy is atypical and has two features - the multiplicity of the main arteries and their atypical divergence (abdominal aorta, aortic bifurcation, common iliac and hypogastric arteries). In 1966 A.Ya. Pytel and Yu.A. The tartar was suggested to consider the level of the renal arterial divergence from the aorta as an absolute anatomical sign of kidney dystopia. For the norm, the renal arteries are removed at the level of the body I of the lumbar vertebrae, which happens in 87% of the patients. Other levels of renal arterial ablation from the aorta are characteristic of renal dystopia. Proceeding from this, it is necessary to distinguish the following types of kidney dystopia.

• Subdiaphragmatic kidney dystopia. The renal arteries recede at the level of the XII thoracic vertebra, as a result of which the kidney is very high and can even be located in the thorax (thoracic kidney).
• Lumbar dystopia of the kidney. The renal arteries extend from the aorta at the level from the II lumbar vertebrae to the aortic bifurcation, whereupon the kidney is located somewhat lower than usual.
• Ivy renal dystopia. Characteristic is the departure of the renal arteries from the common iliac arteries, as a result of which the kidney is located in the ileum.
• Pelvic kidney dystopia. The renal arteries move away from the internal iliac artery, so that the kidney can occupy a medial position in the sacral cavity or between the rectum and bladder in men and in the douglas space in women. The ureter in this kidney is always short.

In the foreign literature, these variants of dystopias are not strictly distinguished.

Crossover (heterolateral) kidney dystopy is characterized by the displacement of one or both kidneys on the opposite side, so it can be one-sided and two-sided. Crossover (heterolateral) kidney dystopy occurs after the kidney has moved upward above the aortic bifurcation. The kidney in this anomaly is an independent, anatomically and functionally fully developed organ, as each methanephros flow is introduced into its methanephrogenic blastema. Very often, the cross (heterolateral) and asymmetrical dystopia (L-shaped, S-shaped) are mistakenly combined into one group.

They differ in that, in the course of development with asymmetric dystopia, both methanephrosis channels are introduced into one metanephrogenic blastema, often leading to a common cortical layer and a fibrous capsule. Dystopia of the kidney in the fused kidneys is always secondary, because in the process of development these kidneys are not able to mix up.

[7], [8], [9], [10]

Symptoms of the kidney dystopia

Symptoms of kidney dystopia depend on its type. The greatest clinical significance is the pelvic dystopia of the kidney. This circumstance is caused by the pressure of the kidney on neighboring organs (iliac vessels, pelvic sympathetic nerve plexus, rectum, bladder, uterus), and therefore clinical manifestations can occur even in the absence of a pathological process in the abnormal kidney. In addition, a dystopic kidney is often taken for volume education, and surgical intervention has its own peculiarities and difficulties. There are known observations of pelvic dystopia of a single kidney and even tragic cases of removal of such a kidney taken for a tumor.

Analyzing the location of the renal artery in the pelvic dystopia, in half of the observations it departs from the common iliac artery, and not from the internal iliac, as A.Ya. Pytel and Yu.A. The tattoo, and the orientation was more of a medial arrangement in the sacral fossa. Most of the dystopic kidneys (75%) have abnormal blood supply. Symptoms of lumbar dystopia of the kidney are not so significant. Much more important is thoracic dystopia of the kidney, as often an abnormal kidney is taken for such diseases as an abscess, a tumor, a ruptured pleurisy.

[11], [12], [13], [14],

Diagnostics of the kidney dystopia

Traditional radiation methods of diagnosis (ultrasound, isotopic renography, excretory and retrograde urography) allow one to suspected a particular type of kidney dystopia with a high probability. Traditional angiography provides information on angioarchitectonics and, accordingly, on the location variant.

[15], [16], [17], [18]

Treatment of the kidney dystopia

Modern diagnostic methods (MSCT, MRI) accurately determine the type of kidney dystopia, urodynamics, relationships with neighboring organs and help to choose the optimal method of treatment with which the kidney dystopia will be cured.