NLS-Method In Vascular Pathology Diagnosis

S.M. Patrushev,

A.D. Sluzky, V.M. Vagulin

Today the world faces a constant trend of a growing rate of mortality caused by occlusive

vascular diseases, especially by cerebro-vascular disorders which are in the third place

among death causes. On the one hand the trend is caused by a growing number of elderly

and aged patients. On the other hand many men even already at 45 have atherosclerotic

damage of main head arteries, causing the need for a medical observation.

The most simple and at the same time informative method of non-invasive diagnosis of

occlusive damage of peripheral vessels appeared to be the NLS-method which has been

used in clinical practice for a short time. The first NLS devices equipped with analog

trigger sensors, operating in 1.4 GHz frequency mode and used in clinical practice since

the late 90-s have not lost their importance yet. They can help determine the condition of

certain sections of the main vessels in the lower limbs and that of the brachio-caphalic

vessels.

Not only the condition of the vessels but also that of the valve system within deep veins

can be studied. 102 patients were examined in 1997-1998 to detect valve insufficiency of

deep veins affected by varicosis. The patients were from 21 to 67 years old. The

examined patients included 25 men (24.5%) and 77 women (75.5%). The study was

carried out by means of a NLS device using a 1.4GHz analog trigger sensor. In 32

patients a valve insufficiency of the femoral vein was detected, in 44 patients failure of

both femoral and popliteal veins. NLS enables to assess the condition of the valve

system of deep veins in low limbs on a noninvasive and objective basis. This enables

appropriate surgical intervention and can be used as an alternative to phlebography

analysis.

The NLS-digital spectral analysis method has no contra-indications and in terms of

informational content is comparable to angiography. It can be used to perform screening

in the course of poly-clinical examination with a view to detect early or latent forms of

vascular pathology and also as a preliminary method for selecting patients for angio-

surgical treatment, since according to some specialists, angiography should only be

performed on candidates for surgery picked out after a preliminary NLS investigation.

However, this method does not assess the bulk index of the bloodstream, because NLS

does not provide a vessel’s image and thus is unable to measure the vessel’s diameter.

This kind of information may be acquired with the help of Doppler systems with 3D-

imaging, that offer duplex and triplex scanning (the so-called Doppler chromatic

charting).

The NLS-method was developed in the mid 90-s and played an essential role in vascular

pathology diagnosis. The main advantage of the NLS-method was that it facilitated

search and location of the vessels and facilitated rapid differentiation of vessels from

nonvascular structures, arteries from veins and very accurate detection of signs of

19disturbed vascular permeability caused by stenosis or occlusion of the vessel lumen by an

atherosclerotic patch or a thrombus: both of which are generally not visible at scanning in

B-mode alone.

In addition the NLS-method enables diagnose of portal hypertension, the extent of its

intensity, and permeability of Porto systemic bypasses. NLS is very sensitive in defining the

extent of peri-pancreatic vessel involvement with pancreatic cancer: essential in

selecting the approach for surgical treatment. NLS facilitates detection of the damaged

renal vessels (both veins and arteries): invaluable for the correct choice of a hypotensive

drug at arterial hypertension.

Some efficient hypotensive drugs, i.e. inhibitors of angiotensin converting enzyme (ACE)

such as capoten, enalapril, bezlipril, etc., have became very popular lately, but they have

counter-indications at renal artery stenosis. So physicians should bear in mind that

checking for stenosis is a must before prescribing this kind of medicine. The NLS-

method is likely to be the choice method in such cases.

The NLS-method is indispensable for differential diagnosis of benign and malignant

hepatic diseases. Its sensitivity is comparable with the potentials of conventional or

digitial angiography and computer-assisted amplified tomography. In addition, the

NLSmethod is much cheaper, simpler and more intelligible. It can be employed directly at the

patient’s bedside if required. The NLS-method may be used in opthalmology to check ocular

hemodynamics before or after surgical intervention, in obstetrics to detect the disturbed

blood current in umbilical cord arteries with a view to diagnose a retarted

fetus development and predict a negative perinatal produce.

Yet another potential of NLS method lies in cranial scanning which enables to detect

intracranial hematomas, aneurisms, cysts and tumors in the encephalon.

These are far from all potentials of the NLS method.

Summing up, the NLS-method is one of the most dynamic techniques and within the next few

years it is bound to bring some new discoveries.