Renovascular hypertensia

Description:

Renovascular hypertensia (RVG) is the increase in the ABP caused by narrowing of a renal artery or its branches. A stenosis reduction of a gleam of a vessel more than 75% from initial or the dilatation following the place of narrowing, more than 50% is considered. The bilateral stenosis or a stenosis of the only kidney lead to bystry development of a renal failure. However prevalence of RVG among all patients having hypertensia is small and makes from 1 to 5%.

Symptoms of Renovascular hypertensia:

The course of renovascular hypertensia depends on the reason which caused it. Clinically it is necessary to think of renovascular hypertensia when arterial pressure increases at young age, has stable character and reaches high level. Similar features of hypertensia are observed at its bystry development in senior citizens (after 40-50 years) owing to atherosclerotic damage of a renal artery or its branches. Preferential and substantial increase of diastolic arterial pressure and small scope of pulse pressure, for example 120/100, 130/110, 160/120 and 240/160 mm of mercury is characteristic of renovascular hypertensia., what always forces to assume a possibility of renovascular hypertensia.

Not less important clinical symptom of this form of hypertensia is lack of effect or insignificant effect of antihypertensives or their combinations. In any case there is a clear resistance and resistance to hypotensive therapy. However, use of the latest antihypertensives and their combinations allows to achieve more or less essential lowering of arterial pressure sometimes. Therefore this symptom in itself cannot serve as the reliable criterion which is speaking well for renovascular hypertensia. Its diagnostic value increases only in the presence of other symptoms of renovascular hypertensia. Signs of systemic lesion of vessels like a panarteritis of an aorta and its branches (Takayasu's disease) also can testify to a renovascular origin of hypertensia.

In 40-80% of cases when narrowing a renal artery it is possible to listen to systolic noise if to place a phonendoscope at the left either to the right of a navel or in a waist in the place of a projection of narrowing of a renal artery. This noise is more often and best of all listened at a fibromuskulyarny dysplasia, than at ateroskleretichesky or other narrowing of a renal artery.

Renovascular hypertensia considerably more often than arterial hypertension of other origin, the malignant current gets. So, at hemilesion of a renal artery it is observed at 25-30%, and at bilateral - at 50-65% of patients (L. A. Pyrig, 1984). For comparison it is possible to remind that the malignant option of an idiopathic hypertensia meets only in 0,1-1% of cases (E. M. Tareev, 1972; N. A. Ratner, 19T4). High and stable level of hypertensia, the expressed changes from an eyeground are characteristic of a malignant current (hemorrhage, retina amotio, etc.), hearts (a myocardial infarction, a left ventricular failure) and brain vessels (strokes, thromboses, etc.). At the same time hypertensive crises at renovascular hypertensia meet less than at an idiopathic hypertensia. Unlike symptomatic renal hypertensia of other genesis (a glomerulonephritis, pyelonephritis, etc.) for renovascular hypertensia are uncharacteristic uric syndrome signs - proteinuria, a hamaturia, a cylindruria. Only in the separate hard proceeding cases (approximately at 1/z patients) the insignificant unstable proteinuria can be observed.

Reasons of Renovascular hypertensia:

Now more than 20 diseases and morbid conditions which can cause renovascular hypertensia are known (L. A. Pyrig, 1984).

In 60-85% of cases the main reason for renovascular hypertensia at the age of 40-50 years is also more senior damage of a renal artery or its branches ateroklerozy is. Consider that clinical displays of renovascular hypertensia arise only when the atheromatous plaque narrows an artery gleam for 50-90%. It is characteristic that atherosclerotic plaques are localized preferential at the mouth or at a proximal third of a renal artery (N. A. Lopatkin, B. B. Mazo, 1975). The right and left renal arteries are surprised approximately equally often. Much less often atherosclerotic changes are noted in the field of bifurcation of a renal artery and in its branches. Hemilesion of a renal artery whereas its bilateral defeat meets approximately in 1/3 cases is in most cases observed and brings to heavier course of renovascular hypertensia which at 2/z patients gains malignant character. According to L. A. Pyriga, in 10% of cases atherosclerosis of renal arteries can be complicated by thrombosis. The disease (by 2-3 times) meets at men more often.

The renal artery stenosis can be a consequence of a fibromuskulyarny dysplasia (hyperplasia) which as the reason of renovascular hypertensia takes the second place after atherosclerosis, and according to N. A. Ratner (1974), is observed not flight of atherosclerosis. The fisbromuskulyarny dysplasia preferential at young and even children's age (from 12 to 44 years) meets; middle age makes 28-29 years (N. A. Lopatkin, E. B. Mazo, 1975; M. D. Knyazev, G. S. Krotovsky, 1977). It is found in women by 4-5 times more often than at men. The etiology of a disease is unknown, but there is an opinion that it can be inborn.

Morphologically fibromuskulyarny dysplasia is shown in the form of the dystrophic and sclerosing changes capturing preferential average and in a smaller measure an outside cover of renal arteries and their branches. At the same time the hyperplasia of muscular elements of a wall can be combined with formation of microaneurysms. Alternation of sites of narrowings and expansions (aneurisms) is as a result observed that gives to arteries a peculiar form - strings of pearls or a beads (N. A. Ratner, 1974; E. E. Gogin et al., 1983). In certain cases preferential internal cover of vessels (intim) with development of the expressed hyperplasia is surprised that it gives the grounds to speak about an intimalny form of a fibromuskulyarny dysplasia. Pathological process though has widespread character, but in 2/z cases is unilateral (L. A. Pyrig, 1984).

Takayasu's disease, or the disease of lack of pulse called still can be one of the reasons of renovascular hypertensia as nonspecific aortoarteriit or a panarteritis of an aorta and its branches. The disease is for the first time described by the oculist Takayasu in 1908. It has widespread character with possible involvement in pathological process and vessels of kidneys.

Among other reasons of renovascular hypertensia 17-22% of cases fall to the share of a nonspecific aortoarteriit of renal arteries (L. A. Pyrig, 1984). Morphologically the disease is characterized by an allergic inflammation with a picture of fibrinoid swelling and a necrosis of connecting fabric, the hyperplasia of walls of arteries causing narrowing or their full obliteration. At the same time easing or even disappearance of pulse on one of extremities is noted, as formed the basis for the name of an aortoarteriit a disease of lack of pulse. The etiology of a disease is unknown. On a pathogeny it is carried to autoimmune diseases. Clinically it is characterized by signs of active inflammatory process and is followed by the subfebrile temperature, a leukocytosis, increase in SOE, a hypergammaglobulinemia, increase in indicators of DFA or sialine test, fibrinogen, emergence of S-reactive protein. At defeat of vessels of kidneys heavy renovascular hypertensia develops. As the disease has system character, surgical treatment of the renovascular hypertensia caused by it ineffectively or in general it is inefficient.

The panarteritis of an aorta and its branches on renal arteries and development of renovascular hypertensia happens to distribution one - or bilateral and is observed at persons of both sexes, but is preferential at young women. Begins usually at the age of 11-20 years, and in 2-3 years it is already shown by narrowing of renal arteries. In addition to possible full occlusion of branches of an aorta owing to inflammatory process, the changed walls of vessels contribute to formation of blood clots. In some cases also thrombosis of a renal artery with a syndrome of an acute renal failure can develop.

Renovascular hypertensia can develop owing to a prelum of a renal artery and its large branches nearby the growing tumor, a hematoma, as a result of thrombosis or an embolism of a renal artery, formation of aneurism, an inborn stenosis of renal vessels (in 5-6% of cases), hypoplasias of the main renal arteries, a nephroptosis, a tumor, a cyst, anomaly of development of kidneys, etc.

Treatment of Renovascular hypertensia:

The most effective method of treatment of renovascular hypertensia - surgical, directed at an opportunity to elimination of the reason of a stenozirovaniye of renal arteries and to recovery of a normal renal blood-groove. Till 1952 the nephrectomy which was used at obviously hemilesion and in far come disease stage was the only method of surgical treatment. The nephrectomy is applied and now if narrowing of intra renal vessels prevails or at the expressed hypoplasia of the affected kidney and considerable disturbance of its function. Organ-preserving operations of reconstructive character are widely used. Results of surgical treatment of subjects are more effective, than the diagnosis of renovascular hypertensia and the reason of its emergence are established earlier.

At the same time even at a malignant current sometimes it is possible to achieve good effect by means of individually picked up antihypertensives from patients with renovascular hypertensia. Conservative hypotensive therapy remains by the only method of treatment of renovascular hypertensia which reason the panarteritis of an aorta and its branches (renal arteries) when surgical treatment cannot be recommended in connection with systemacity of defeat of vessels is.