Diagnosis of aneurysm rupture

Diagnosis of rupture of an aneurysm is carried out on the basis of the clinical picture described above and data of additional methods of investigation. At the same time, age, information on concomitant diseases (vasculitis, diabetes, blood diseases, renal hypertension, hypertension) must be taken into account.

More often aneurysms burst in young and middle-aged people who do not have an anamnesis of arterial hypertension, although the presence of the latter does not exclude the possibility of aneurysm rupture. If in the past similar attacks of sudden headache with impaired consciousness and focal neurological symptoms have occurred, it is possible to assume with a high degree of probability an aneurysm hemorrhage. At the same time, if there were more than three such seizures and the patient is functionally preserved, it is worth considering the rupture of arteriovenous malformation, since their course is less severe.

An important method is the measurement of blood pressure on both brachial arteries. Arterial hypertension in persons who had not had it before, confirms the hypothesis of a possible hemorrhage from an aneurysm.

A simple, affordable and diagnostically valuable method of verifying subarachnoid hemorrhage is lumbar puncture. It can be produced in the next few hours after the rupture and is absolutely indicated in the presence of meningeal syndrome.

Contraindications to the lumbar puncture are:

• dislocation syndrome;
• occlusion of the liquor-conducting pathways;
• pronounced violations of vital functions: Cheyne-Stokes respiratory distress, Biota, terminal; unstable blood pressure with a tendency to decrease (systolic pressure 100 mm and below);
• presence of an intracranial hematoma in the posterior
• cranial fossa. 

A lot of CSF should not be withdrawn, as it can provoke repeated bleeding. It is only necessary to measure the cerebrospinal pressure and take 2-3 ml to study, to make sure that the admixture of blood in the cerebrospinal fluid is not the result of technically incorrect manipulation. As is known, the pathognomonic feature of the hemorrhage occurred is a significant admixture of blood in the cerebrospinal fluid. Often it is visually difficult to understand whether it is pure blood or a liquor intensively stained with blood. The latter is confirmed by the high pressure of the liquor measured by the manometer and by a simple test consisting in applying the drop on a gauze napkin (a drop of blood has a monochromatic red color, while a blood-colored liquor leaves a two-color drop: in the center is an intensely stained spot It is surrounded by a halo of orange or pink color). If it is blood that has descended from the cerebral subarachnoid spaces, then during centrifugation in the sediment there will be a lot of hemolyzed erythrocytes, and in the supernatant - free hemoglobin, due to which its color will be pink or scarlet. When conducting a study in a delayed period, when the process of sanitation of the CSF is already under way, the latter will have a xanthochromic color. Even in the case of late hospitalization, it is possible to determine the presence of blood impurities in the cerebrospinal fluid by spectrophotometric analysis of cerebrospinal fluid, which allows the detection of hemoglobin degradation products after 4 weeks.

An important modern method for diagnosing aneurysm rupture and monitoring of constrictive - stenotic arteriopathy is ultrasound transcranial dopplerography, the significance of which is very significant in the diagnosis and selection of therapeutic tactics. The method is based on the well-known Doppler effect: the ultrasonic signal reflected from the moving blood elements changes its frequency, the degree of which determines the linear velocity of the blood flow. Its acceleration testifies (according to Bernoulli's law) about the narrowing of the lumen of the investigated vessel-angiospasm or arteriopathy. Multisegmentary and diffuse arteriopathy is characteristic for rupture of an aneurysm, and the more pronounced narrowing of the lumen, the greater the systolic blood flow velocity and the higher the pulsation index (PI-LSSC-LSCDAST / LSKsredn, where LSKsred "= LSKsist + LCKdast / 2).

Depending on this, a moderate, pronounced and critical arteriopathy is isolated. These data allow you to choose the right therapeutic tactics. If a patient has a critical arteriopathy, surgical treatment is contraindicated. Carrying out transcranial dopplerography in dynamics makes it possible to assess the state of cerebral blood flow, on the basis of which to choose the optimal time for conducting surgical intervention with a minimum in individual terms, the degree of deterioration in the prognosis. As already indicated, this period most often occurs 12-14 days after the rupture of the aneurysm. Applying Nimotop from the first day of hemorrhage allows you to perform the operation at an earlier time. The dynamics of constriction of the lumen of the vessels correlates with the clinic: the deepening of ischemia is accompanied by a worsening of the patient's condition, the growth of focal neurologic symptoms, the progressive violation of consciousness.

A similar correlation is observed with the data of axial computed tomography (ACT). The latter has not only diagnostic, but also prognostic value, allowing you to choose the right treatment tactics and predict the outcome. According to the ACT, SAK can be detected, in some cases, local accumulation of blood in basal cisterns can provide information about the localization of an aneurysm ruptured. In 15-18% of patients ACT reveals intracerebral hematomas of different volume, intraventricular hemorrhages. Of great importance is the severity of the dislocation syndrome: deformation and displacement of the ventricles of the brain, visualization and the state of the bridging bridge casing. With temporo-tentorial wedging, this tank is deformed, or not visualized at all, which has a poor prognostic value. Along with this, ACT makes it possible to visualize the zone of ischemic edema of the brain with the details of its size and localization.

Depending on the severity of the condition, the clinical picture, the data of transcranial Doppler ultrasound, ACT, electroencephalography (EEG), three degrees of severity of cerebral ischemia due to angiospasm - arteriopathy: compensated, subcompensated and decompensated.

1. Compensated ischemia is characterized by: the state of patients corresponding to I-II degrees in H-H; mild focal symptomatology; CSA involving 2-3 segments of the arteries of the base of the brain; ischemia according to axial computed tomography, covering 1-2 parts of the brain; II type of EEG (according to VV Lebedev, 1988 - moderate violation of bioelectrical activity of the brain, zonal changes are preserved.) In the occipital leads, a polymorphic alpha rhythm is recorded, in the anteroenteral leads there is a non-clearly expressed a-0 activity).
2. Subcompensated ischemia: the status of patients corresponding to grade III in H-H; a pronounced symptom complex corresponding to the area of arterial spasm and ischemia; spread of CSA to 4-5 segments of arteries; spread of ischemic process according to ACT by 2-3 parts; III type of EEG (pronounced disturbances in electrical activity, disturbance of a - rhythm against the background of polymorphic activity of a - 0 range with recording of flares of high amplitude bilaterally synchronous slow wave activity of more than 1 ms duration).
3. Decompensated ischemia: severity of the condition according to H-H IV-V degree; gross focal neurological symptoms, up to complete loss of functions; CSA is distributed to 7 segments of basal arteries and more; the prevalence of ischemia by ACT is 4 or more; IV type of EEG changes (gross violations of the bioelectrical activity of the brain, the activity of the bilateral-synchronous character of the A-band dominates over all leads).

The severity of the condition of the patients in the first day after the rupture of the aneurysm depends not so much on arteriopathy (which does not yet have time to develop and the narrowing of the arteries due to myogenic mechanisms and can be qualified as arterioscasms), how much from the massiveness of the SAK, the breakthrough of blood in the ventricles of the brain, the presence and localization of the intracerebral hematoma, while on the 4th-7th day, and especially in the 2nd week, the severity of the condition is mainly determined by the severity of arteriopathy. Given this pattern, the above gradation is not entirely acceptable for all periods of the course of hemorrhage and makes it possible to determine the operational risk due to the development of ischemia with late admission of patients using multivariate analysis. Thus, in case of compensation of cerebral ischemia, operative intervention can be undertaken immediately, with a subcompensated state, the question of intervention is solved individually. Decompensated ischemia is a contraindication for surgical treatment and such patients are subject to active conservative therapy until their condition improves (as a rule, this becomes possible after 3-4 weeks in surviving patients).

The "gold standard" in the diagnosis of arterial aneurysms of cerebral vessels is cerebral angiography. It allows to identify the aneurysmal sac carrying its artery, the severity of the neck and sometimes the daughter sack (the rupture site), the presence of thrombi within the aneurysm, the severity and prevalence of arteriopathy. The informative value of angiography depends on the method of investigation and the resolving diagnostic ability of the angiographic apparatus. Modern angiographs are equipped with a computer-assisted mathematical processing system for angiographic images, which makes it possible to increase the contrast of the necessary section of the artery, increase its size, and eliminate the image of bone structures and secondary vessels superimposed on the area under investigation (digital subtraction angiography). This technique has advantages over the usual multi-series in view of the availability of the possibilities: contrasting all the pools in one study with minimal use of contrast medium, continuous demonstration of contrast agent progress along the vascular channel (video monitoring) with the possibility of calculating the linear velocity of blood flow; conducting a multi-axis, at any desired angle, angiography.

The accuracy of diagnosis with this technique reaches 95%. However, an angiographic study conducted in an acute period may be false-negative. In a number of cases (2%), this is possible due to an aneurysmal sac with thrombotic masses or a pronounced spasm of the adjacent segment of the artery with no contrast to the structure. Repeated examinations are conducted after 10-14 days and allow to reveal an aneurysm. According to the world literature, these pathological structures are found in 49-61% of patients with SAK. The remaining hemorrhages are due to other causes (microaneurysms, not visualized angiographically, arterial hypertension, neoplasms, amyloid angiopathy, coagulopathies, atherosclerotic lesion of the vessel wall, vasculitis, hereditary hemorrhagic telangiectasia).

Contraindications for the study are:

• gross central respiratory disorders (tachypnea, pathological respiration, stopping spontaneous breathing), severe tachyarrhythmia;
• unstable systemic arterial pressure with a tendency to hypotension, including medically maintained at a level of 100 mm (at a pressure below 60 mm in angiography, the phenomenon of "stop-contrast" or pseudo-carotid thrombosis is observed due to excess pressure in the cavity of the skull of pressure in the internal carotid artery, at which blood with contrast does not penetrate into the intracranial vessels and an aneurysm is impossible to diagnose);
• respiratory disorders due to occlusion of the airways (before its elimination).

In the case of patient IV-V according to NN, the study can be carried out only in case of urgent surgery; in opposite cases it is advisable to postpone it until the patient's condition improves.

Methods of angiography are different, but they can all be divided into two groups: puncture and catheterization. Puncture techniques are performed according to Seldinger and differ only in which of the arteries is punctured to introduce a contrast agent into it. Carotid angiography (the introduction of contrast into the common carotid artery) and axillary angiography (introduction of contrast into the axillary artery) are most often performed. The latter allows to contrast the vertebral artery, and if done on the right, then the basins of the right vertebral and right carotid arteries are contrasted.

The puncture method makes it possible to get a good contrast of the arteries, is easier to tolerate by patients and gives less complications, because requires the introduction of a smaller amount of contrast agent. Its disadvantage is the inability for one study to obtain information about all the arterial basins of the brain. Therefore, in the diagnosis of aneurysms, catheterization or selective angiography is often used. Usually a catheter is inserted through the femoral artery into the arch of the aorta, and from there it is consistently carried to all arteries that supply blood to the brain. Thus, for one study you can get information about all the arterial basins of the brain. This is especially important when the clinic and the data of additional research methods fail to establish the localization of an aneurysm. In addition, information about all basins is needed because, as already mentioned, 10-15% have several aneurysms of various arteries. The disadvantage of the method is its laboriousness. The duration of the study and the need to use a large amount of contrast medium, which in a number of cases can cause complications in the form of deepening of angiospasm and the growth of cerebral ischemia. As a rule, these phenomena are reversible and are successfully eliminated medically.

[1], [2], [3]