Facial artery branch. Branches of the external carotid artery

The common carotid artery (a. carotis communis), right and left, is directed vertically upward in front of the transverse processes of the cervical vertebrae. Next to the common carotid artery are the internal jugular vein and the vagus nerve. At the level of the upper edge of the thyroid edge, the common carotid artery divides into the external and internal carotid arteries. External carotid artery, a. carotis externa, is one of the two terminal branches of the common carotid artery. The artery divides into its terminal branches - the superficial temporal and maxillary arteries. On its way, the external carotid artery gives off a number of branches that extend from it in several directions. The anterior group of branches consists of the superior thyroid, lingual and facial arteries. The posterior group includes the sternocleidomastoid, occipital and posterior auricular arteries. The ascending pharyngeal artery is directed medially. Anterior branches of the external carotid artery: 1. Superior thyroid artery, a. thyreoidea superior, departs from the external carotid artery at its beginning, is divided into anterior and posterior branches, rr. anterior et posterior. The anterior and posterior branches are distributed in the thyroid gland. The following lateral branches depart from the artery: 1) superior laryngeal artery, a. laryngea superior, which supplies blood to the muscles and mucous membrane of the larynx; 2) sublingual branch, g. infrahyoideus; 3) sternocleidomastoid branch, sternocleidomastoideus, and 4) cricothyroid branch, cricothyroideus, supplying blood to the muscles of the same name.2. Lingual artery, a. lingudlis, branches from the external carotid artery. The artery gives off dorsal branches, rr. dorsales linguae. Its final branch is the deep artery of the tongue, a. profunda linguae. Two branches depart from the lingual artery: 1) the thin suprahyoid branch, suprahyoideus and 2) the hypoglossal artery, a. sublingualis, going to the sublingual gland and adjacent muscles3. Facial artery, a. facialis, arises from the external carotid artery. The lingual and facial arteries can begin with a common lingual-facial trunk, truncus linguofacialis. The artery is adjacent to the submandibular gland, giving it glandular branches, rr. glanduldres.Branches in the neck depart from the facial artery: 1) ascending palatine artery, a. palatina ascendens, to the soft palate; 2) tonsil branch, tonsillaris, to the palatine tonsil; 3) submental artery, a. submentalis, to the chin and neck muscles. 4) inferior labial artery, a. labialis inferior, and 5) superior labial artery, a. labialis superior. 6) angular artery, a. apgularis. Posterior branches of the external carotid artery: 1. Occipital artery, a. occipitdlis, arises from the external carotid artery, branches in the skin of the back of the head into the occipital branches, rr. occipitdles. Lateral branches depart from the occipital artery: 1) sternocleidomastoid branches, rr. sternocleidomastoidei, to the muscle of the same name; 2) auricular branch, rr. auriculdris, to the auricle; 3) mastoid branch, mastoideus, to the dura mater of the brain; 4) descending branch, r. disсendens, to the muscles of the back of the neck.2. Posterior auricular artery, a. auricularis posterior, originates from the external carotid artery. Its auricular branch, Messrs. auricularis, and the occipital branch, g. occipitdlis, supply the skin of the mastoid region, auricle and back of the head. One of the branches of the posterior auricular artery is the stylomastoid artery, a. stylomastoidea, gives off the posterior tympanic artery, a. tympanica posterior, to the mucous membrane of the tympanic cavity and the cells of the mastoid process. The medial branch of the external carotid artery is the ascending pharyngeal artery, a. pharyngea ascendens. From it depart: 1) pharyngeal branches, rr. pharyngeales, to the muscles of the pharynx and to the deep muscles of the neck; 2) posterior meningeal artery, a. meningea posterior, follows into the cranial cavity through the jugular foramen; 3) inferior tympanic artery, a. tympanica inferior, through the lower opening of the tympanic canaliculus penetrates into the tympanic cavity. Terminal branches of the external carotid artery: 1. Superficial temporal artery, a. temporalis superficialis, is divided into the frontal branch, g. frontalis, and the parietal branch, g. parietalis, feeding the epicranial muscle, the skin of the forehead and crown. A number of branches depart from the superficial temporal artery: 1) under the zygomatic arch - branches of the parotid gland, rr. parotidei, to the salivary gland of the same name; 2) transverse artery of the face, a. transversa faciei, to the facial muscles and skin of the buccal and infraorbital areas; 3) anterior auricular branches, gg. auriculares anteriores, to the auricle and external auditory canal; 4) above the zygomatic arch - zygomatic orbital artery, a. zygomaticoorbitalis, to the lateral corner of the orbit, supplies blood to the orbicularis oculi muscle; 5) middle temporal artery, a. temporalis media, to the temporal muscle.2. Maxillary artery, a. maxillaris, splits into its terminal branches. It has three sections: maxillary, pterygoid and pterygopalatine.

The external carotid artery at the level of the neck of the mandible is divided into the superficial temporal and maxillary. The branches of the external carotid artery can be divided into three groups: anterior, posterior and medial.

The anterior group includes: 1. superior thyroid artery - gives blood to the larynx, thyroid gland, and neck muscles.

The lingual artery supplies the tongue, the muscles of the floor of the mouth, the sublingual salivary gland, tonsils, and the mucous membrane of the mouth and gums.

The facial artery supplies blood to the pharynx, tonsils, soft palate, submandibular gland, oral muscles, and facial muscles.

The posterior group of branches is formed by: 1. The occipital artery, which supplies blood to the muscles and skin of the back of the head, the auricle, and the dura mater. 2. The posterior auricular artery supplies blood to the skin of the mastoid process, the auricle, the back of the head, the mucous membrane of the cells of the mastoid process and the middle ear.

The medial branch of the external carotid artery is the ascending pharyngeal artery. It departs from the beginning of the external carotid artery and gives branches to the pharynx, deep muscles of the neck, tonsils, auditory tube, soft ear, middle ear, and dura mater of the brain.

The terminal branches of the external carotid artery include: 1. The superficial temporal artery, which in the temporal region is divided into the frontal, parietal, auricular branches, as well as the transverse facial artery and the middle temporal artery. It supplies blood to the muscles and skin of the forehead, crown, parotid gland, temporal and facial muscles. 2. The maxillary artery, which passes in the infratemporal and pterygo-subpalatine fossae, along the way breaks down into the middle meningeal, inferior alveolar, infraorbital, descending palatine and sphenopalatine arteries. It supplies blood to the deep areas of the face and head, the middle ear cavity, the mucous membrane of the mouth, the nasal cavity, masticatory and facial muscles.

3.Incretory function of the pancreas. Islet apparatus (islets of Langerhans). Hormones secreted by alpha, beta and gamma cells. The functional role of hormones, mechanism, mechanism of their action, pathological conditions associated with their hypo- and hypersecretion.

The endocrine part of the pancreas is represented by the islets of Langerhans,

Islets are made up of cells - insulinocytes, among which, based on the presence of granules with different physical, chemical and morphological properties, 5 main types are distinguished:

· beta cells that synthesize insulin;

alpha cells producing glucagon;

delta cells that form somatostatin;

· D 1 cells secreting VIP;

· PP cells that produce pancreatic polypeptide.

In addition, immunocytochemistry and electron microscopy showed the presence in the islets of a small number of cells containing gastrin, thyrotropin-releasing hormone and somatoliberin.

The physiological significance of insulin is to regulate carbohydrate metabolism and maintain the required level of glucose in the blood by reducing it. Glucagon has the opposite effect. Its main physiological role is to regulate blood glucose levels by increasing it; in addition, it affects metabolic processes in the body. Somatostatin inhibits the release of insulin and glucagon, the secretion of hydrochloric acid by the stomach and the entry of calcium ions into the cells of the pancreatic islets.

Insulin promotes the conversion of glucose into glycogen and enhances carbohydrate metabolism in muscles. Glucagon enhances the formation of triglycerides from fatty acids and stimulates their oxidation in hepatocytes. As the concentration of glucose in the blood flowing through the pancreas increases, insulin secretion increases and blood glucose levels decrease. Somatostatin inhibits the production of growth hormone by the pituitary gland, as well as the release of insulin and glucagon by A and B cells. Pancreatic polypeptides stimulate the secretion of gastric and pancreatic juice by exocrinocytes of the pancreas.

Islet cell hormones have a significant impact on metabolic processes.

Glucose homeostasis in the body is maintained within very strict limits (3.3-5.5 mmol/l), which is provided mainly by 2 key hormones - insulin and glucagon.

Insulin is a protein hormone with a molecular weight of 6000. It is formed from proinsulin. The conversion of proinsulin into the active hormone occurs in beta cells. Regulation of insulin secretion is carried out by the sympathetic and parasympathetic nervous system, as well as under the influence of a number of hormones that are produced in the gastrointestinal tract. Insulin is an anabolic hormone with a broad spectrum of action. Its role is to increase the synthesis of carbohydrates, fats and proteins. It enhances glucose metabolism, increases the penetration of glucose into myocardial and skeletal muscle cells. Insulin lowers blood glucose levels, stimulates glycogen synthesis in the liver, and affects fat metabolism.

Glucagon is a polypeptide with a mass of 3500. Regulation of glucagon secretion occurs with the help of glucose receptors in the hypothalamus, which detect a decrease in blood glucose levels. This chain includes somatostatin, enteroglucagon, and the sympathetic nervous system.

The main effect of glucagon is associated with increased metabolic processes in the liver,

the capture of glycogen to glucose and its release into the bloodstream.

When blood glucose levels deviate from normal, hypo- or hyperglycemia occurs. With a lack of insulin or a change in its activity, the glucose level in the blood increases sharply, which can lead to the development of DIABETES MELLITUS.

High levels of glucagon in the blood cause the development of hypoglycemic conditions.

There are mainly 2 main pathologies caused by disruption of the endocrine pancreas: diabetes mellitus (chronic hyperglycemia syndrome) and hypoglycemia syndrome (rare clinical symptom complexes caused by tumors such as glucagonoma, VIPoma, somatostatinoma are not covered).

DIABETES– a systemic heterogeneous disease caused by insulin deficiency: absolute – in insulin-dependent (IDDM, or type I) or relative – in non-insulin-dependent (NIDDM, or type II). Impaired glucose utilization and hyperglycemia are the first manifest signs of a total disorder of all types of metabolism.

In healthy individuals, the blood glucose concentration does not exceed 6.4 mmol/l (115 mg%). If the fasting blood glucose level is equal to or greater than 7.8 mmol/L (140 mg%), then the diagnosis of diabetes is beyond doubt. The diagnosis can be confirmed by determining the content of glycosylated hemoglobin in the blood.

Radioimmunological methods are used to determine gastrin, insulin, vasoactive intestinal polypeptide (VIP) in the blood if a hormonally active pancreatic tumor is suspected (gastrinoma, insulinoma, VIPoma).

Possible disorders of the endocrine function of the pancreas, manifested in the form of functional hyperinsulinism. This condition is observed more often in obese people, especially women, and is clinically manifested by attacks of weakness, sweating and other symptoms of mild hypoglycemic syndrome 3-4 hours after eating food containing easily digestible carbohydrates.

1. Superficial temporal artery, a. temporalis superficialis, is a continuation of the trunk of the external carotid artery, passes upward in front of the auricle (partially covered at the level of its tragus by the posterior part of the parotid gland) into the temporal region, where its pulsation is palpable above the zygomatic arch in a living person.

At the level of the supraorbital edge of the frontal bone, the superficial temporal artery is divided into the frontal branch, r. frontalis, and the parietal branch, r. parietalis, feeding the supracranial muscle, the skin of the forehead and crown and anastomosing with the branches of the occipital artery. A number of branches depart from the superficial temporal artery: 1) under the zygomatic arch - branches of the parotid gland, rr. parotidei, to the salivary gland of the same name; 2) the transverse artery of the face located between the zygomatic arch and the parotid duct, a. transversa faciei, to the facial muscles and skin of the buccal and infraorbital areas; 3) anterior auricular branches, rr. auriculares anteriores, to the auricle and external auditory canal, where they anastomose with the branches of the posterior auricular artery; 4) above the zygomatic arch - zygomatic orbital artery, a. zygomaticoorbitalis, to the lateral corner of the orbit, supplies blood to the orbicularis oculi muscle; 5) middle temporal artery, a. temporalis media, to the temporal muscle.

2. Maxillary artery, a. maxillaris, is also the terminal branch of the external carotid artery, but larger than the superficial temporal artery. The initial part of the artery is covered on the lateral side by the branch of the mandible. The artery reaches (at the level of the lateral pterygoid muscle) to the infratemporal muscle and further to the pterygopalatine fossa, where it splits into its terminal branches. According to the topography of the maxillary artery, three sections are distinguished in it: maxillary, pterygoid and pterygopalatine.

Fig. 4 Branches of the maxillary artery

From the maxillary artery within its maxillary section depart: 1) the deep auricular artery, a. auriculdris profunda, to the temporomandibular joint, external auditory canal and tympanic membrane; 2) anterior tympanic artery, a. tympdnica anterior, which through the petrotympanic fissure of the temporal bone follows to the mucous membrane of the tympanic cavity; 3) relatively large inferior alveolar artery, a. alveolaris inferior, entering the canal of the lower jaw and giving off dental branches along its path, rr. dentales. This artery leaves the canal through the mental foramen as the mental artery, a. mentalis, which branches in the facial muscles and in the skin of the chin. Before entering the canal, a thin mylohyoid branch branches off from the inferior alveolar artery, r. mylohyoideus, to the muscle of the same name and the anterior belly of the digastric muscle; 4) middle meningeal artery, a. meningea, is the most significant of all the arteries that supply the dura mater of the brain. Penetrates into the cranial cavity through the foramen spinosum of the greater wing of the sphenoid bone, giving off there the superior tympanic artery, a. tympanica superior, to the mucous membrane of the tympanic cavity, frontal and parietal branches, rr. frontarietalits, to the dura mater of the brain. Before entering the foramen spinosum, the meningeal accessory branch, the meningeus accessorius (r. accessories), departs from the middle meningeal artery, which first, before entering the cranial cavity, supplies blood to the pterygoid muscles and the auditory tube, and then, passing through the oval foramen into the skull, sends branches to the dura mater of the brain and to the trigeminal ganglion.

Within the pterygoid region, branches feeding the masticatory muscles depart from the maxillary artery: 1) masticatory artery, a. masseterica, to the muscle of the same name; 2) deep temporal [anterior] and (temporal posterior) arteries, a. temporalis profunda (anterior) and (a. temporalis posterior), extending into the thickness of the temporal muscle; 3) pterygoid branches, rr. pterygoidei, to the muscles of the same name; 4) buccal artery, a. buccalis, to the buccal muscle and to the mucous membrane of the cheek; 5) posterior superior alveolar artery, a. alveolaris superior posterior, which, through the openings of the same name in the tubercle of the upper jaw, penetrates into the maxillary sinus and supplies its mucous membrane with blood, and its dental branches, rr. dentales, - teeth and gums of the upper jaw.

Three terminal branches depart from the third - pterygopalatine - section of the maxillary artery: 1) infraorbital artery, a. infraorbitalis, which passes into the orbit through the inferior fissure, where it gives branches to the inferior rectus and oblique muscles of the eye. Then, through the infraorbital foramen, this artery through the canal of the same name onto the face and supplies blood to the facial muscles located in the thickness of the upper lip, in the area of ​​the nose and lower eyelid, and the skin covering them. Here the infraorbital artery anastomoses with the branches of the facial and superficial temporal arteries. In the orbital canal, the anterior superior alveolar arteries, aa, depart from the infraorbital artery. alveolares superiores anteriores, giving off dental branches, rr. dentales, to the teeth of the upper jaw; 2) descending palatine artery, a. palatina descendens, is a thin vessel, which, at the beginning, gave off the artery of the pterygoid canal, a. canalis pterygoidei, to the upper part of the pharynx and auditory tube and passing through the greater palatine canal, supplies the hard and soft palates (aa. palatinae major et minores), anastomoses with the branches of the ascending palatine artery; 3) sphenopalatine artery, a. sphenopalatina, passes through the opening of the same name into the nasal cavity and gives off the lateral posterior nasal arteries, aa. nasales pasteriores laterals, and posterior septal branches, rr. septales pasteriores, to the nasal mucosa.

Internal carotid artery, a. carotis interna, supplies blood to the brain and organ of vision. The initial section of the artery is its cervical part, pars cervicalis, located laterally and posteriorly, and then medially from the external carotid artery. Between the pharynx and the internal jugular vein, the artery rises vertically (without giving off branches) to the external opening of the carotid canal. Behind and medially from it are the sympathetic trunk and the vagus nerve, in front and laterally - the hypoglossal nerve, above - the glossopharyngeal nerve. In the carotid canal there is a stony part, pars petrosa, of the internal carotid artery, which forms a bend and gives off the thin carotid-tympanic arteries, aa, into the tympanic cavity. caroticotympanicae. Upon leaving the canal, the internal carotid artery bends upward and lies in the short groove of the same name in the sphenoid bone, and then the cavernous part, pars cavernosa, of the artery passes through the cavernous sinus of the dura mater of the brain. At the level of the optic canal, the cerebral part, pars cerebralis, of the artery makes another bend, convexly facing forward, gives off the ophthalmic artery and, at the inner edge of the anterior inclined process, divides into its terminal branches - the anterior and middle cerebral arteries.

Fig.5 Internal carotid and vertebral arteries

1. Ophthalmic artery, a. ophthalmica, departs in the area of ​​the last bend of the internal carotid artery and, together with the optic nerve, enters the orbit through the optic canal. Next, the ophthalmic artery follows along the medial wall of the orbit to the medial corner of the eye, where it splits into its terminal branches - the medial arteries of the eyelids and the dorsal artery of the nose. The following branches depart from the ophthalmic artery: 1) lacrimal artery, a. lacrimalis, follows between the superior and lateral rectus muscles of the eye, giving them branches, to the lacrimal gland; The thin lateral arteries of the eyelids, aa, are also separated from it. palpebrales lateralis; 2) long and short posterior ciliary arteries, aa. ciliares posteriores longae et breves, pierce the sclera and penetrate the choroid of the eye; 3) central retinal artery, a. centralis retinae, enters the optic nerve and

Fig. 6 Branches of the ophthalmic artery

reaches the retina; 4) muscular arteries, aa. musculares, to the superior rectus and oblique muscles of the eyeball; 5) posterior ethmoidal artery, a. ethmoidalis posterior, follows the mucous membrane of the posterior cells of the ethmoid bone through the posterior ethmoidal opening; 6) anterior ethmoidal artery, a. ethmoidalits anterior, passes through the anterior ethmoidal opening, where it divides into its terminal branches. One of them is the anterior meningeal artery [branch], a. meningeus anterior, enters the cranial cavity and supplies the dura mater of the brain with blood, while others penetrate under the cribriform plate of the ethmoid bone and nourish the mucous membrane of the ethmoid cells, as well as the nasal cavity and the anterior parts of its septum; 7) anterior ciliary arteries, aa. ciliares anteritores, in the form of several branches accompany the muscles of the eye: suprascleral arteries, aa. episclerdles enter the sclera, and the anterior conjunctival arteries, aa. contunctvales anteriores, supply blood to the conjunctiva of the eye; 8) supratrochlear artery, a.

Supratrochlearis, leaves the orbit through the frontal foramen (together with the nerve of the same name) and branches in the muscles and skin of the forehead;

Rice. 7 Arteries and veins of the eyelids, front view

1 - supraorbital artery and vein, 2 - nasal artery, 3 - angular artery (terminal branch of the facial artery - 4), 5 - supraorbital artery, 6 - anterior branch of the superficial temporal artery, 6' - branch of the transverse facial artery, 7 - lacrimal artery , 8 - superior artery of the eyelid, 9 - anastomoses of the upper artery of the eyelid with the superficial temporal and lacrimal, 10 - lower artery of the eyelid, 11 - facial vein, 12 - angular vein, 13 - branch of the superficial temporal vein.

9) medial arteries of the eyelids, aa. palpebrales mediales, go to the medial corner of the eye, anastomose with the lateral arteries of the eyelids (from the lacrimal artery), forming two arches: the arch of the upper eyelid, arcus palpebralis superior, and the arc of the lower eyelid, arcus palpebralis inferior; 10) dorsal artery of the nose, a. dorsalis nasi, passes through the orbicularis oculi muscle to the corner of the eye, where it anastomoses with the angular artery (the terminal branch of the facial artery). The medial arteries of the eyelids and the dorsal nasal artery are the terminal branches of the ophthalmic artery.

2. Anterior cerebral artery, a. cerebri anterior, departs from the internal carotid artery slightly above the ophthalmic artery, approaches the artery of the same name on the opposite side and is connected to it by a short unpaired communicating artery, a. communicans anterior. Then the anterior cerebral artery lies in the groove of the corpus callosum, goes around the corpus callosum and goes towards the occipital lobe of the cerebral hemisphere, supplying blood to the medial surfaces of the frontal, parietal and partly occipital lobes, as well as the olfactory bulbs, tracts and striatum. The artery gives off two groups of branches to the substance of the brain - cortical and central.

3. Middle cerebral artery, a. cerebri media is the largest branch of the internal carotid artery. It distinguishes between the sphenoid part, pars sphenoi dali s, adjacent to the large wing of the sphenoid bone, and the insular part, pars i~nsulari s. The latter rises upward, enters the lateral sulcus of the cerebrum, adjacent to the insula. Then it continues into its third, terminal (cortical) part, pars terminalis (pars corticalis), which branches on the superolateral surface of the cerebral hemisphere. The middle cerebral artery also gives off cortical and central branches.

4. Posterior communicating artery, a. communicans postdrior, extends from the end of the internal carotid artery until the latter divides into the anterior and middle cerebral arteries. The posterior communicating artery is directed towards the bridge and at its anterior edge flows into the posterior cerebral artery (a branch of the basilar artery).

5. Anterior villous artery, a. choroidea anterior, is a thin vessel that arises from the internal carotid artery behind the posterior communicating artery, penetrates the lower horn of the lateral ventricle, and then into the third ventricle. With its branches it participates in the formation of choroid plexuses. It also gives off numerous thin branches to the gray and white matter of the brain: to the optic tract, lateral geniculate body, internal capsule, basal ganglia, hypothalamic nuclei and red nucleus. The following arteries participate in the formation of anastomoses between the branches of the internal and external carotid arteries: a. dorsalis nasi (from the ophthalmic artery) and a. angularis (from the facial artery), a. supratrochlearis (from the ophthalmic artery) and g. frontalis (from the superficial temporal artery), a. carotis interna and a. cerebri posterior (through the posterior communicating artery).

Subclavian artery, a. subclavia, starts from the aorta (left) and brachiocephalic trunk (right). The left subclavian artery is approximately 4 cm longer than the right. The subclavian artery leaves the thoracic cavity through its upper aperture, goes around the dome of the pleura, enters (together with the brachial plexus) into the interscalene space, then passes under the clavicle, bends over 1 rib (lies in its groove of the same name) and below the lateral edge of this rib penetrates into axillary cavity, where it continues as the axillary artery. Conventionally, the subclavian artery is divided into three sections: 1) from the point of origin to the inner edge of the anterior scalene muscle, 2) in the interscalene space and 3) at the exit from the interscalene space. In the first section, three branches depart from the artery: the vertebral and internal thoracic arteries, the thyrocervical trunk, in the second section - the costocervical trunk, and in the third - sometimes the transverse artery of the neck.

1. Vertebral artery, a. vertebralis, the most significant of the branches of the subclavian artery, departs from its upper semicircle at the level of the VII cervical vertebra. The vertebral artery has 4 parts: between the anterior scalene muscle and the longus colli muscle is its prevertebral part, pars prevertebra. Next, the vertebral artery goes to the VI cervical vertebra - this is its transverse process (cervical) part, pars transversaria (cervicalis), then passes upward through the transverse foramina of the VI-II cervical vertebrae. Coming out of the transverse foramen of the II cervical vertebra, the vertebral artery turns laterally and the next section is the atlas part, pars atlantica. Having passed through the hole in the transverse process of the atlas, it bends around from behind its superior articular fossa [surface], pierces the posterior atlanto-occipital membrane, and then the hard shell of the spinal cord (in the spinal canal) and through the foramen magnum enters the cranial cavity - here its intracranial part begins , pars intracranialis. Posterior to the pons, this artery joins a similar artery on the opposite side to form the basilar artery. The spinal (radicular) branches, rr, depart from the second, transverse process, part of the vertebral artery. spinales (radiculares), penetrating through the intervertebral foramina to the spinal cord, and muscle branches, rr. musculares, to the deep muscles of the neck. All other branches are separated from the last - intracranial part: 1) anterior meningeal branch, r. meningeus anterior, and posterior meningeal branch, r. meningeus posterior / meningeal branches, rr. meningei]; 2) posterior spinal artery, a. spinalis posterior, goes around the medulla oblongata from the outside, and then descends along the posterior surface of the spinal cord, anastomosing with the artery of the same name on the opposite side; 3) anterior spinal artery, a. spinalis anterior, connects with the artery of the same name on the opposite side into an unpaired vessel, heading down in the depths of the anterior fissure of the spinal cord; 4) posterior inferior cerebellar artery (right and left), a. The inferior posterior cerebelli, going around the medulla oblongata, branches in the posterior inferior parts of the cerebellum.

Basilar artery, a. basilaris, an unpaired vessel, is located in the basilar groove of the bridge. At the level of the anterior edge of the bridge, it is divided into two terminal branches - the posterior right and left cerebral arteries. From the trunk of the basilar artery depart: 1) the anterior inferior cerebellar artery (right and left), a. inferior anterior cerebelli, branch on the lower surface of the cerebellum; 2) artery of the labyrinth (right and left), a. labyrinthi, pass next to the vestibulocochlear nerve (VIII pair of cranial nerves) through the internal auditory canal to the inner ear; 3) arteries of the bridge, aa. pontis (branches to the bridge); 4) middle cerebral arteries, aa. mesencephalicae (branches to the midbrain); 5) superior cerebellar artery (right and left), a. superior cerebelli, branches in the upper parts of the cerebellum.

Rice. 8 Arteries forming the Circle of Willis

Posterior cerebral artery, a. cerebri posterior, goes around the cerebral peduncle, branches on the lower surface of the temporal and occipital lobes of the cerebral hemisphere, gives off cortical and central branches. The artery communicans posterior (from the internal carotid artery) flows into the posterior cerebral artery, resulting in the formation of the arterial (Willisian) circle of the cerebrum, circulus arteriosus cerebri.

The right and left posterior cerebral arteries, which close the arterial circle at the back, participate in its formation. The posterior communicating artery connects the posterior cerebral artery with the internal carotid on each side. The anterior part of the arterial circle of the cerebrum is closed by the anterior communicating artery, located between the right and left anterior cerebral arteries, which arise from the right and left internal carotid arteries, respectively. The arterial circle of the cerebrum is located at its base in the subarachnoid space. It covers the optic chiasm from the front and sides; The posterior communicating arteries lie on each side of the hypothalamus, the posterior cerebral arteries are in front of the pons.

External carotid artery, a. carotis externa, supplies blood to the outer parts of the head and neck, which is why it is called external in contrast to the internal carotid artery, which penetrates the cranial cavity. From its origin, the external carotid artery rises upward and passes inward from the posterior abdomen of the m. digastrici and m. stylohyoideus, pierces the parotid gland and, behind the neck of the condylar process of the mandible, divides into its terminal branches.

The branches of the external carotid artery are for the most part remnants of arterial arches and nourish the organs arising from the branchial arches. They go (number 9) as if along the radii of a circle corresponding to the head, and can be divided into three groups of three arteries each - the anterior, middle and posterior groups, or triplets.

The anterior group is determined by the development and location of the organs supplied by the arteries of this group and which are derivatives of the branchial arches, namely: the thyroid gland and larynx - a. thyroidea superior, tongue - a. lingualis and faces - a. facialis.

1. A. thyroidea superior, the superior artery of the thyroid gland, departs from the external carotid artery immediately above its beginning, goes down and forward to the thyroid gland, where it anastomoses with other thyroid arteries. Along the way he gives a. laryngea superior, which together with n. laryngeus superior perforates lig. thyrohyoideum and supplies branches to the muscles, ligaments and mucous membrane of the larynx.
2. A. lingualis, lingual artery, departs at the level of the greater horns of the hyoid bone, goes up through Pirogov's triangle, covered by m. hyoglossus, and goes to the tongue. Before entering it, it gives off branches to the hyoid bone, palatine tonsils and sublingual gland. Having entered the tongue, the trunk of the lingual artery continues to the tip of the tongue called a. profunda linguae, which along the way gives off multiple branches to the back of the tongue, rr. dorsales linguae.
3. A. facialis, facial artery, departs slightly higher than the previous one at the level of the angle of the lower jaw, passes inwards from the posterior abdomen of m. digastricus and reaches the anterior edge of m. masseter, where it bends over the edge of the jaw onto the face. Here, in front of m. masseter, it can be pressed against the lower jaw. Next, it goes to the medial corner of the eye, where the terminal branch (a. angularis) anastomoses with a. dorsalis nasi (branch of a. ophthalmica from the internal carotid artery system). Before bending through the lower jaw, it gives branches to nearby formations: to the pharynx and soft palate, to the palatine tonsils, to the submandibular gland and diaphragm of the mouth, to the salivary glands; after the bend - to the upper and lower lips. Back group.
4. A. occipitalis, the occipital artery, lies in the groove on the processus mastoideus, appears under the skin in the occipital area, branches to the crown. On its way a. occipitalis gives a number of small branches: to the surrounding muscles, to the auricle, to the dura mater of the brain in the posterior cranial fossa.
5. A. auricularis posterior, the posterior auricular artery, goes up and back to the skin behind the auricle. Its branches are distributed in the auricle, in the skin and muscles of the back of the head, as well as in the tympanic cavity, where its branch penetrates through the foramen stylomastoidieum.
6. A. sternocleidomastoidea - to the muscle of the same name. The middle group consists of remnants of arterial arches.
7. A. pharyngea ascendens, the ascending pharyngeal artery, goes up the wall of the pharynx, supplying it, the soft palate, palatine tonsil, auditory tube, tympanic cavity and dura mater of the brain.
8. A. temporalis superficialis, the superficial temporal artery, one of the two terminal branches of the external carotid artery, runs as a continuation of the trunk a. carotis externa in front of the external auditory canal to the temple, located under the skin on the fascia of the temporal muscle. Here the artery may be pressed against the temporal bone. Its terminal branches, ramus frontalis and ramus parietalis, branch in the region of the crown and temple. Along the way, it gives branches to the parotid gland, to the lateral surface of the auricle and to the external auditory canal; Some of the branches go to the back of the face, to the outer corner of the eye, to m. orbicularis oculi and zygomatic bone. A. temporalis superficialis also supplies m. temporalis.
9. A. maxillaris, the maxillary artery, is the other terminal branch of the external carotid artery. To facilitate the study of its branches, its short trunk is divided into three sections: the first goes around the neck of the jaw, the second passes into the fossa infratemporalis along the surface of m. pterygoideus lateralis, the third penetrates into the fossa pterygopalatina.

The branches of the first section go upward to the external auditory canal, into the tympanic cavity, where they penetrate through the fissura petrotympanica; to the dura mater of the brain - a. meningea media, middle meningeal artery (the largest branch), where it penetrates through the foramen spinosum, and down to the lower teeth, a. alveolaris inferior, inferior alveolar artery. The latter passes into the lower jaw through the canalis mandibulae. Before joining the channel a. alveoldris inferior gives r. mylohyoideus to the sonominal muscle, and in the canal it supplies the lower teeth with its branches and leaves it through the foramen mentale, receiving the name a. mentalis, which branches in the skin and muscles of the chin.

The branches of the second section go to all the chewing and buccal muscles, receiving names corresponding to the muscles, as well as to the mucous membrane of the sinus maxillaris and the upper molars - aa. alveolares superiores posteriores, posterior superior alveolar arteries.

Branches of the third department:

1. a. infraorbital, the infraorbital artery, enters the orbit through the fissura orbitalis inferior, then through the canalis infraorbitalis it enters the anterior surface of the upper jaw and sends branches to the lower eyelid, to the lacrimal sac and down to the upper lip and cheek. Here it anastomoses with the branches of the facial artery, so that if blood flow in the trunk of a. maxillaris blood can enter its pool through a. facialis. Still in the eye socket a. infraorbitalis gives branches to the muscles of the eyeball; passing in the infraorbital canal, it supplies the canine and incisors with branches (aa. alveolares superiores anteribres) and the mucous membrane of the sinus maxillaris;
2. branches to the palate, pharynx and auditory tube, some of which descend down into the canalis palatinus major, exit through the foramina palatina majus et minores and branch in the hard and soft palate;
3. a. sphenopalatina, the sphenopalatina artery, penetrates through the opening of the same name into the nasal cavity, giving branches to its lateral wall and to the septum; the anterior part of the nasal cavity receives blood through the aa. ethmoidales anterior et posterior (from a. ophthalmica).

CAROTID ARTERIES- paired elastic arteries that supply blood to the head and most of the neck.

Embryology

General S. a. differentiate in the embryo from the part of the ventral aortas between the III and IV branchial arteries. Over the further course, the ventral aortas between the I and III branchial arteries are transformed into external S. a. Internal S. a. develop from the third pair of branchial arteries and from parts of the dorsal aorta between the I and III branchial arteries.

By the time of birth, internal S. a. forms the first bend in the cavernous sinus.

Anatomy

Right common S. a. (a. carotis communis dext.) originates from the brachiocephalic trunk (truncus brachiocephalicus) at the level of the right sternoclavicular joint; left common S. a. (a. carotis communis sin.) - from the aortic arch (see), it is 20-25 mm longer than the right one. General S. a. exit the thoracic cavity through the upper thoracic opening and are directed upward in the fascial perivascular sheaths on the sides of the trachea and esophagus, and then to the larynx and pharynx. Laterally there is the internal jugular vein, a chain of deep cervical lymph nodes, between the vessels and behind - the vagus nerve, in front - the upper root of the cervical loop. The scapulohyoid muscle crosses the common S. a. in the middle third (color fig.). Posteriorly, at the level of the lower edge of the cricoid cartilage, on the transverse process of the VI cervical vertebra there is a carotid tubercle (Chassegnac’s tubercle), and the general S. a is pressed against it. for the purpose of temporarily stopping bleeding when she is wounded. At the level of the upper edge of the thyroid cartilage, general S. a. are divided into external and internal S. a. Before division, common S. a. they don't give away branches.

External S. a. in the proximal part it is covered by the sternocleidomastoid muscle, then it is located in the carotid triangle and is covered by the subcutaneous muscle of the neck. Before the artery enters the retromandibular fossa, it is crossed in front by the hypoglossal nerve, the stylohyoid muscle and the posterior belly of the digastric muscle. Deeper lie the superior laryngeal nerve with the styloglossus and stylopharyngeal muscles, which separate the external S. a. from internal. Above the muscles attached to the styloid process, the artery penetrates into the thickness of the parotid gland. Medial to the neck of the articular process of the mandible, it is divided into terminal branches - the superficial temporal artery and the maxillary artery.

The anterior branches of the external S. a. are the superior thyroid artery (a. thyroidea sup.), from which the superior laryngeal artery (a. laryngea sup.) departs, the lingual artery (a. lingualis) and the facial artery (a. facialis), sometimes having a common origin with the lingual artery. Posterior branches of S. a. - the sternocleidomastoid artery (a. sternocleidomastoidea), which supplies blood to the muscle of the same name, the occipital artery (a. occipitalis) and the posterior auricular artery (a. auricularis post.). The medial branch is the ascending pharyngeal artery (a. pharyngea ascendens), the terminal superficial temporal artery (a. temporalis superficialis) and the maxillary artery (a. maxillaris).

Thus, external S. a. vascularizes the scalp, facial and masticatory muscles, salivary glands, oral cavity, nose and middle ear, tongue, teeth, partially dura mater, pharynx, larynx, thyroid gland.

Internal S. a. (a. carotis int.) starts from the bifurcation of the common carotid artery at the level of the upper edge of the thyroid cartilage and rises to the base of the skull. In the neck area, internal S. a. is part of the neurovascular bundle together with the internal jugular vein (v. jugularis int.) and the vagus nerve (n. vagus). The artery is encircled medially by the superior laryngeal nerve, in front - by the facial vein, the posterior belly of the digastric muscle, and the hypoglossal nerve, from which the upper root of the cervical loop departs. At the very beginning, internal S. a. lies outward from the external S. a., but soon passes to the medial side and, heading vertically, is located between the pharynx and the muscles attached to the styloid process. Next, the artery bends around the glossopharyngeal nerve.

In the cranial cavity internal S. a. passes through the carotid canal, where it is accompanied by nerve and venous plexuses (plexus caroticus int. et plexus venosus caroticus int.). According to the course of the carotid canal, the internal S. a. makes the first bend forward and inward, then in the carotid sulcus the second bend is upward. At the level of the sella turcica, the artery bends anteriorly. Near the optic canal, the internal S. a. forms a fourth bend upward and posteriorly. In this place it lies in the cavernous sinus. After passing through the dura mater, the artery is located in the subarachnoid space on the lower surface of the brain.

Conditionally internal S. a. divided into four parts: cervical (pars cervicalis), stony (pars petrosa), cavernous (pars cavernosa) and cerebral (pars cerebralis). The first branches extending from the inner S. a. in the carotid canal are the carotid-tympanic branches (rr. caroti-cotympanici), which pass in the tubules of the same name in the pyramid of the temporal bone and supply blood to the mucous membrane of the tympanic cavity.

In the cavernous sinus, the artery gives off a number of small branches that vascularize its walls, the trigeminal ganglion and the initial parts of the branches of the trigeminal nerve. At the exit from the cavernous sinus, the ophthalmic artery (a. ophthalmica), posterior communicating artery (a. communicans post.), anterior villous artery (a. choroidea ant.), middle cerebral artery (a. cerebri med.) depart from the internal carotid artery. and anterior cerebral artery (a. cerebri ant.).

Internal S. a. vascularizes the brain and its dura mater (see Cerebral circulation), the eyeball with its auxiliary apparatus, the skin and muscles of the forehead.

Internal S. a. has anastomoses with the external S. a. through the dorsal artery of the nose (a. dorsalis nasi) - a branch of the ophthalmic artery (a. ophthal-mica), the angular artery (a. angularis) - a branch of the facial artery (a. facialis), the frontal branch (g. frontalis) - a branch of the superficial temporal artery (a. temporalis superficialis), as well as with the main artery (a. ba-silaris), formed from two vertebral arteries (aa. vertebra-les). These anastomoses are of great importance for the blood supply to the brain when the internal carotid artery is turned off (see Brain, blood supply).

Innervation of the general S. a. and its branches are carried out by postganglionic fibers extending from the upper and middle cervical nodes of the sympathetic trunk and forming a plexus around the vessels - plexus caroticus communis, plexus caroticus ext., plexus caroticus int. The middle cardiac nerve departs from the middle cervical node of the sympathetic trunk, which participates in the innervation of the general S. a.

Histology

Gistol. structure of the wall of S. a. and its blood supply - see Arteries. With age, in the wall of S. a. connective tissue grows. After 60-70 years, focal thickenings of collagen fibers are noted in the inner shell, the internal elastic membrane becomes thinner, and calcareous deposits appear.

Research methods

The most informative methods for studying S. a. are arteriography (see), electroencephalography (see), ultrasound (see Ultrasound diagnostics), computed tomography (see Computer tomography), etc. (see Blood vessels, research methods).

Pathology

The pathology is caused by malformations of S. a., damage and a number of diseases, in which the wall of the arteries is affected.

Developmental defects are rare and usually have a patol character. tortuosity and looping of S. a. The shape and degree of tortuosity of S. a. are different; patol is most often observed. tortuosity of general and internal S. a. (Fig. 1, a). In addition, there are various variations and anomalies of S. a. Thus, sometimes the carotid arteries have a common trunk (truncus bicaroticus), extending from the aortic arch. The brachiocephalic trunk may be absent, then the right common carotid and right subclavian arteries depart from the aortic arch independently. There are also topographic variants associated with anomalies in the development of the aortic arch (see).

In rare cases, from general S. a. the superior and inferior thyroid arteries (aa. thyroid eae sup. et, inf.), the pharyngeal ascending artery (a. pharyngea ascendens), the vertebral artery fa. vertebra-lis). External S. a. may begin directly from the aortic arch. In exceptional cases, it may be absent, while its branches arise from the artery of the same name passing on the other side, or from the common S. a. Number of branches of external S. a. may vary. Internal S. a. very rarely absent on one side; in this case, it is replaced by the branches of the vertebral artery.

In some cases, with malformations of S. a., accompanied by impaired blood supply to the brain, surgical treatment is indicated (see below).

Damage are possible as a result of a gunshot wound to S. a., its injury, for example, with a knife or during surgical interventions on the neck, and are accompanied by massive acute blood loss, thrombosis and the formation of a pulsating hematoma with the subsequent development of a false aneurysm (see).

During surgery for wounds of S. a. First, the proximal part is exposed, and then the distal part. Only after clamping the proximal and distal parts of the artery with atraumatic clamps is the wound area exposed, ligatures are applied above and below the site of injury, a lateral vascular suture or a patch is applied. In cases of the formation of a post-traumatic carotid-cavernous anastomosis, operations are performed to turn it off (see Arterio-sinus anastomosis, carotid-cavernous anastomosis).

Staged treatment of combat injuries to S. a. is carried out according to the same principles as for damage to other blood vessels (see Blood vessels, combat injuries. staged treatment).

Diseases. Diseases leading to damage to the wall of the S. a. are various forms of nonspecific arteritis, atherosclerosis, fibromuscular dysplasia and, extremely rarely, syphilitic aortitis (see).

In patients with rheumatic heart disease with thrombosis of the left auricle or left ventricle of the heart in the presence of atrial fibrillation, as well as in patients with post-infarction large-focal cardiosclerosis, complicated by a cardiac aneurysm and atrial fibrillation, thromboembolism of S. a. may be observed, edges are sometimes accompanied by focal cerebral symptoms (see Thromboembolism).

Nonspecific arteritis (see Takayasu syndrome) occupies one of the central places among lesions of the brachiocephalic trunk (Fig. 1.6). According to B.V. Petrovsky, I.A. Belichenko, V.S. Krylov (1970), it occurs in 40% of patients with occlusive lesions of the branches of the aortic arch, and no more than 20% of them have damage to S. a . Non-specific arteritis is observed in women 3-4 times more often than in men; It usually occurs before the age of 30, but occurs in both childhood and old age. Its etiology is not fully understood. Nowadays, it is believed that nonspecific arteritis is a systemic disease of an allergic and autoallergic nature with a tendency to damage the walls of arterial vessels of the muscular-elastic type. Damage to all layers of the arterial wall results in productive panarteritis, thromboendovasculitis, disorganization and collapse of the elastic frame and complete obliteration of the vessel. Quite rarely, the final stage of development of nonspecific arteritis S. a. is the formation of a true aneurysm as a result of destruction of the elastic membrane of the vessel against the background of arterial hypertension. The proximal part of the general S. a. is most often affected, and the internal and external S. a. remain passable. In patol. the process of nonspecific arteritis may also involve other arteries (see Arteritis, Giant cell arteritis).

Atherosclerosis S. a. It occurs 4-5 times more often in men than in women. Wedge, manifestations of the disease caused by their stenosis or occlusions, develop, as a rule, in people aged 40-70 years. Morphol. the picture of atherosclerosis (see) is characterized by the deposition of lipids in the inner lining of the vessel, the formation of atherosclerotic plaques with their subsequent calcification and ulceration. With ulceration of an atherosclerotic plaque, arterial thrombosis and peripheral embolism with atheromatous masses are often observed. Due to the destruction of the elastic framework of the vessel, true aneurysms can develop. An important factor contributing to the development of true aneurysms of S. a. is the presence of arterial hypertension in the patient. Most often, with atherosclerosis, stenosis of the carotid arteries develops in the area of ​​​​the division of the general S. a. on the internal and external (Fig. 1, c), as well as in the extracranial parts of the internal S. a. Due to the systemic nature of the development of atherosclerosis, it is extremely rare that damage to only one S. is detected. More often, a bilateral process is observed, leading to occlusion, as well as the presence of atherosclerotic stenosis and occlusions in the aorta and main arteries of other organs.

There are more and more reports of the defeat of S. a. according to the type of fibromuscular dysplasia observed in women aged 20-40 years. Some researchers associate this disease with congenital dysplasia of smooth muscle cells of the artery wall, while others tend to consider this disease acquired. Morphologically, fibromuscular dysplasia reveals fibrosis of the muscular layer of the artery wall, areas of stenosis, alternating with areas of aneurysmal dilation. In some cases, either stenotic or aneurysmal forms of fibromuscular dysplasia are detected. Most often, fibromuscular dysplasia is observed in the extracranial parts of S. a., and there is often bilateral damage.

Stenosis of S. a. can also be caused by extravasal factors, among which the most common is a tumor of the carotid gland - chemodectoma (see Paraganglioma). It is extremely rare to observe extravasal compression of S. a. neck tumors and scar processes resulting from inflammation and trauma in this area.

A feature of stenotic lesions of the brachiocephalic trunk, and in particular S. a., is the discrepancy between the wedge, manifestations of impaired blood supply to the brain and the severity of the stenotic process in the arteries. This is due to the large compensatory capabilities of cerebral circulation, a feature of which is the presence of many collateral pathways (see Vascular collaterals). The critical degree of narrowing of the S. a., when the cut may occur, phenomena of insufficiency of blood supply to the brain, is a decrease in its lumen by more than 75%. However, this degree of stenosis of S. a. and even its occlusion does not always lead to acute insufficiency of blood supply to the brain with a wedge, a picture of cerebrovascular accident (see). With S.'s lesions. There are four wedges, stages of cerebral ischemia: I - asymptomatic, II - transient, III - chronic. cerebral vascular insufficiency, IV - residual effects of cerebrovascular accident. Treatment of occlusive and stenotic lesions of S. a. depends on the stage of cerebral ischemia, which is important for determining indications for surgery (see below).

Operations

In the 30-40s. 20th century the only interventions that were performed during narrowing and complete occlusion of the S. a. were operations on the sympathetic nervous system. The first successful reconstructive operation for thrombosis of internal S. a. completed in 1953 by M. De Vechi. In the USSR, the first such operation was performed in 1960 by B.V. Petrovsky. Reconstructive operations on S. a. for their pathology have become feasible in connection with the development of angiography, anesthesiology, vascular reconstructive surgery, the development of new atraumatic instruments, and the improvement of methods for protecting the brain from ischemia.

On S. a. perform ligature and reconstructive operations. Ligatures include ligation of an artery in the wound or throughout (see Ligation of blood vessels) and resection of the artery. Restorative operations include lateral and circular vascular suture, arterial patch, intimalthrombectomy followed by vascular suture or patch, prosthetics, and permanent arterial bypass.

Operations on S. a. performed with the patient in the supine position with a bolster under the shoulder blades, the patient's head is turned in the direction opposite to the side of the operation. A skin incision is made along the inner edge of the sternocleidomastoid muscle from the mastoid process to the manubrium of the sternum (Fig. 2). In some cases, when intervention is necessary on the proximal parts of the common carotid artery, an additional partial sternotomy is performed (see Mediastinotomy).

The correct choice of anesthesia and protection of the brain from ischemia is very important. To resolve the issue of the possibility of surgery on S. a. Without protecting the brain from ischemia, data on the state of blood flow in the circle of Willis (arterial circle of the cerebrum, T.), obtained using functional tests of clamping the S. a., are important. (see Collateral training) with ultrasound flowmetry (see Ultrasound diagnostics). Particular importance is attached to the condition of the collateral vessels connecting the systems of the right and left S. a. If the only affected but passable S. is undergoing reconstruction. (with occlusion of the other), protection of the brain from ischemia is indicated.

On the eve of the operation, patients are prescribed antipsychotics, tranquilizers and antihistamines. In 40 min. Before surgery, 0.3 mg! kg of promedol, 0.2 mg! kg of seduxen, 0.5 mg! kg of pi-polfen and 0.3-0.5 mg of atropine are administered intramuscularly. This premedication has a good tranquilizing effect and facilitates a smooth induction. For induction, a method of combined induction anesthesia with seduxene and fentanyl is used: against the background of inhalation, nitrous oxide and oxygen in a ratio of 2:1 are administered fractionally every 2-3 minutes. 2-3 mg of seduxen, which has an antihypoxic effect. After the first dose of seduxen, 0.004 mg of fentanyl is administered. A sufficient degree of anesthesia usually occurs after administration of a total dose of seduxen 0.17-0.2 mg! kg. Immediately before tracheal intubation, 0.004 mg/kg fentanyl is administered. The induction duration is 11-13 minutes. Anesthesia is maintained with fluorotane (0.25-0.5 vol. %) and a mixture of nitrous oxide and oxygen in a ratio of 2:1 in combination with fractional injections of fentanyl. During anesthesia, constant EEG monitoring is carried out. Before starting the operation for 5 minutes. tentatively clamp S. a. below the affected area; at the same time, continuous recording of EEG (see Electroencephalography), rheoencephalogram (see Rheoencephalography) and electromanometry distal to the clamp are carried out. With normal EEG, rheoencephalogram and pressure in the artery distal to the clamp equal to 40 mm Hg. Art. and moreover, the use of brain protection methods is inappropriate. The appearance on the EEG of incorrectly alternating theta waves or a decrease in the voltage of all recorded potentials is an indication for taking additional measures to protect the brain from ischemia.

There are two fundamentally different ways to protect the brain from ischemia: 1) maintaining blood flow in the brain using internal or external bypass with synthetic tubes or prostheses for the period of reconstruction of the brain; 2) reducing oxygen consumption by brain tissue due to local hypothermia. For this purpose, craniocerebral hypothermia is used (see Artificial hypothermia) using the Cold-2f apparatus. It begins immediately after induction, reducing the temperature to 30-31° in the external auditory canal, which corresponds to a brain temperature of 28-29°. To block thermoregulation and relieve vasoconstriction, in addition to total curarization, droperidol is administered at a dose of 2.5-5.0 mg. At the stage of arterial reconstruction, measures are also taken to improve blood flow and oxygen supply to the brain due to moderate hypercapnia and hypertension obtained by increasing pCO2 and reducing the depth of anesthesia.

Due to the fact that hypothermia leads to a significant increase in blood viscosity and deterioration of tissue perfusion, transfusions of solutions of glucose, rheopolyglucin, polyglucin are carried out, achieving a decrease in hematocrit to 30-35%. After the main stage of the surgical intervention, the patient is warmed first through the helmet of the Cold-2f device, and then with warm air using a hairdryer. During this period, attention is paid to the correction of possible metabolic acidosis (see) due to increasing oxygen consumption by tissues due to increased body temperature. Active warming is carried out gradually up to 36°. Further warming of the patient to normal temperature occurs in the intensive care unit. During this period, prevention of hyperthermic syndrome (see) and cerebrospinal hypertension is carried out by administering suprastin and droperidol. If hypertension persists despite the use of these medications, nitroglycerin in the form of a 1% alcohol solution under the tongue, approximately 0.6 mg (4 drops), is used to reduce pressure. The blood pressure level is maintained at the preoperative level in normotensive patients, and at the level of 150/90-160/95 mm Hg in hypertensive patients. Art.

During reconstructive operations, arteriotomy is performed after clamping the artery with atraumatic clamps proximal and distal to the pathologically changed area. Arteriotomy S. a. can be longitudinal (most often), transverse or oblique, depending on the nature of the patol. process and purpose of the operation. The size of the arterial incision depends on the intended volume of intravascular intervention. Most often, surgical intervention on S. a. performed for atherosclerotic stenosis or complete occlusion. Most often, for this pathology, an intimothrombectomy is performed - thrombendarterectomy (see Atherosclerosis, surgical treatment of occlusive lesions, Thrombectomy). A longitudinal arteriotomy is performed at the site of narrowing and the atherosclerotic plaque is removed along with the altered inner lining of the vessel. Great importance is attached to the prevention of wrapping of the detached inner lining of the vessel at the distal end of the wound. For this purpose, after crossing the inner shell in the transverse direction, it is fixed with sutures to the remaining layers of the vessel wall. If the diameter of S. a. in the area of ​​intimalthrombectomy is quite large, the arterial incision is sutured with a side suture (see Vascular suture). Otherwise, in order to prevent narrowing, the incision of S. a. closed using an autovein patch or vascular prosthesis.

In cases where atherosclerosis with calcification leads to complete destruction of the artery wall, it is preferable to perform resection of the stenotic area followed by autovenous replacement of the removed part of the vessel, since when using synthetic vascular prostheses, various complications are observed much more often (thrombosis of the prosthesis, suppuration followed by arrosive bleeding and so-called expulsion of the prosthesis). A section of the great saphenous vein of the leg is usually used as a plastic material.

With nonspecific arteritis S. a., when patol. the process covers all layers of the artery wall and it is not possible to perform an intimalthrombectomy operation; permanent autovenous bypass shunting is considered the most preferable and safe (see Bypass of blood vessels). For the successful functioning of the shunt, a proximal anastomosis of the artery and autovenous is applied in a place not affected by patol. process. Distal anastomosis of the autovenous vein with S. a. often put end to end. If, for the reconstruction of S. a. an artificial vascular prosthesis is used, special attention should be paid to the thoroughness of hemostasis and wound drainage to prevent the formation of paraprosthetic hematomas, which can cause inflammatory infiltrates and suppuration.

In more than 30% of operations, restore the main blood flow in the S. a. turns out to be impossible. In these cases, it is necessary to limit oneself to an intervention that improves collateral circulation - excision of a segment of thrombosed (obliterated) internal S. a. according to Leriche. In some cases, it is also recommended to perform ganglectomy (see).

In recent years, reports have appeared on the use of the method of dosed internal dilatation of the extracranial sections of S. a. by percutaneous puncture of the femoral artery according to Seldinger (see Seldinger method) and subsequent insertion of a catheter with a balloon inflating at its end into the branch of the aortic arch under X-ray television control (see X-ray endovascular surgery). The main advantage of this method is the ability to avoid surgical intervention in patients with a high risk of surgery (old age, presence of severe concomitant diseases).

The most common complications that arise during operations on S. a. are the development of heart failure and arterial hypotension (see Arterial hypotension). Treatment of heart failure (see) is carried out with cardiac glycosides, diuretics, small doses of nitroglycerin, sometimes in combination with isadrine (isoproterenol) or dopamine; according to indications, artificial ventilation of the lungs is used (see Artificial respiration) with positive end-expiratory pressure. The most serious complication is the appearance or deepening in the postoperative period neurol. symptoms due to cerebral ischemia, embolism or vascular thrombosis (see Stroke). Repeated surgery in case of thrombosis or embolism often leads to complete regression of neurol. symptoms. In the case of cerebral ischemia in the postoperative period, all efforts should be aimed at the prevention and treatment of cerebral edema (see Edema and swelling of the brain). Encouraging results have been obtained through the use of hyperbaric oxygenation (see).

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M. D. Knyazev; N. V. Krylova (an., embr.), M. H. Seleznev (an.).