Manual_of_Cardiovascular_Surgery

Manual of Cardiovascular Surgery

  • Plovdiv, 2019
  • Zaprin Vazhev

Authors:

  • Asen Ivanov
  • Bogomila Cheshmedzhieva
  • Buryan Kirov
  • Valentin Vasilev
  • Valentina Cholakova
  • Vasil Batselov
  • Vasil Panitsa
  • Georgi Flristov
  • Dimitar Batashki
  • Dimitar Yondov
  • Drago Zhetev
  • Evgenii Ivanov
  • Zaprin Vazhev
  • Ivan Bachvarov
  • Konstantin Dimitrov
  • Petar Slavov
  • Todor Gonovski
  • Flristo Rahman
  • Flristo Stoev
  • Yani Zahariev

Contents

  • HUMAN HEART ANATOMY - 5
  • CARDIAC SURGERY ASPECTS - 5
  • IMAGING DIAGNOSTIC METHODS IN CARDIOVASCULAR SURGERY - 27
  • CARDIOPULMONARY BYPASS - 36
  • ANESTHESIA IN CARDIAC AND VASCULAR SURGERY - 46
  • VALVULAR HEART DISEASES - 68
  • ANEURYSMS AND DISSECTIONS OF THE THORACIC AORTA - 81
  • CONGENITAL HEART DEFECTS - 128
  • ASSESSMENT OF PATIENTS WITH VASCULAR DISEASES - 145
  • VASCULAR TRAUMA - 153
  • ACUTE ARTERIAL INSUFFICIENCY - 156
  • TEMPORARY AND PERMANENT ELECTROCARDIOSTIMULATION - 159
  • SUPERIOR VENA CAVA SYNDROME - 163
  • INFERIOR VENA CAVA SYNDROME - 167
  • RAYNAUD'S SYNDROME - 171
  • EXTRACRANIAL VASCULAR DISEASES - 175
  • ABDOMINAL AORTIC ANEURYSMS AND ANEURYSMS OF THE LOWER LIMBS - 182
  • CHRONIC ARTERIAL INSUFFICIENCY OF TF{E LOWER EXTREMITIES - 192
  • VENOUS THROMBOSIS _ DEEP AND SUPERFICIAL - 206
  • CHRONIC VENOUS INSUFFICIENCY - 210
  • LYMPTIATIC DISORDERS - 216
  • AMPUTATION IN THE VASCULAR PATHOLOGY - 227

Human Heart Anatomy / Cardiac Surgery Aspects

  • The human heart is a hollow muscular organ which, through synchronized and regular contractions, impels the blood throughout the closed cardiovascular system.
  • The normal heart of a healthy adult:
    • Beats 70 times per minute, on average
    • Around 100 000 times per 24 hours a day
    • Transports approximately 7500 liters of blood.
  • The heart has an irregular, conical shape.
  • Externally and visually distinguished are:
    • The base and apex of the heart
    • The anterior, inferior and two lateral surfaces
  • The base of the heart is rotated upwards, rightwards and backwards.
  • Great cardiac blood vessels come out from the base of the heart:
    • Ascending aorta
    • Main pulmonary trunk
    • Superior and inferior venae cavae
    • Two pairs of pulmonary veins.
  • Consequently, the heart hangs down the mentioned vessels.
  • The apex of the heart is rotated downwards, leftwards and ahead and thus it comes into contact with the internal surface of the thoracic wall.
  • In slender and asthenic habitus individuals, a localized vibration on the thoracic wall during either regular, or irregular heart beats, can be observed and eventually - manually palpated.
  • This localized vibration on the thoracic wall is termed ictus cordis (Latin).
  • The anterior surface of the heart, (facies sternocostalis,Latin) is convex and is in contact with the undersurface of the breast bone, (sternum) and III-VI cartilaginous ribs.
  • The inferior surface, (facies diaphragmatica, Latin) is flat and the heart with its inferior surface lies over the tendinous centre of the thoracic diaphragmatic muscle.
  • The two lateral surfaces, (facies pulmonales, Latin) touch the mediastinal pleurae and consequently the mediastinal surfaces of the lungs.
  • As a result, on the mediastinal surfaces of both lungs, marked impressions, termed impressiones cardiacae (Latin), are formed.
  • The anterior and inferior surfaces of the heart converge and form the so called acute margin, in which left segment, near the cardiac apex, there is another surface anatomy mark, termed incisura apicis cords (Latin).
  • There are a few grooves on the heart's surface which externally mark the demarcation between the four cardiac chambers.
  • The coronary arteries, covered by various amount of fat tissue, lie within these demarcation grooves.
  • A circular groove, termed sulcus coronarius (Latin), is the demarcation between the two atria and corresponding ventricles.
  • In front, sulcus coronarius is interrupted by the main pulmonary trunk/artery.
  • The proprietary blood vessels of the heart - right (RCA), left (LCA) coronary arteries and coronary venous sinus, lie within the sulcus coronarius.
  • Another anterior (on the anterior sterno-costal surface), and posterior (on the inferior diaphragmatic surface of the heart) grooves commence down, from the coronary groove, towards the cardiac apex.
  • The two grooves: anterior and posterior interventricular, mark the border between the right and left ventricles.
  • Coronary arteries are located within the mentioned grooves.
  • The size of the heart varies among individuals.
  • The fact that it reflects the size of a human's fist is commonly and conceptually accepted.
  • The weight of the heart is around 250-300 gr., which in fact represents 1/25 part of the human body weight.
  • In women, the heart has relatively lower weight, compared to male's heart, due to the more grainy female physique by nature.
  • ln a healthy new-born, the heart without any congenital malformation, weighs around 15-20 gr. and it proportionally develops along with the general development of the maturing organism.

Topographic Anatomy of the Heart

  • The heart is located in the middle mediastinum - a topographic area within the thoracic cavity.
  • It is asymmetrically situated, with its 2/3 being to the left and 1/3 to the right of the midline plane of the human body.
  • The cardiac axis is located and oriented from above, to the right, and aback towards the left, down and forward, and thus forming a 45 degree angle with the axis of the body.
  • The heart as a whole is twisted around its axis from right to the left.
  • Thus, the anterior sterno-costal surface is separated by the interventricular groove into a right larger and left smaller part, and the inferior diaphragmatic surface - into alarger left and smaller right part.
  • Consequently the right atrium and ventricle are positioned forward, whereas the left atrium and ventricle are rearwards.
  • The heart is wrapped by a serous sheath termed pericardium.
  • The components of the anterior mediastinum are located in front of the pericardium wrapped heart.
  • The elements of the anterior mediastum are: the thymus, lymph nodes, and internal thoracic blood vessels.
  • The front surface of the heart is not completely covered by the lungs and pleura, since their left and right borders are separated and thus form and surround an area termed trigonum pericardicum (area interpleurica inferior.)
  • Through it the heart along with its pericardium comes to contact with the undersurface of the sternum and the IV, V and Vi left rib cartilages of the thoracic cage.
  • In clinical practice, this area refers to the absolute cardiac dullness, usually assessed by percussion.
  • The front portions of the lungs are laterally located from the triangle between the front surface of the heart and the chest wall, and this is the area of relative cardiac percussion dullness.
  • The components of the posterior mediastinum: oesophagus, descending thoracic aorta, vagal nerves (oesophageal plexus), thoracic duct, are situated behind the heart.
  • Laterally, the heart contacts with the mediastinal surfaces of both lungs and forms an impression - impressio cardiaca, better expressed on the right.
  • Downwards, the heart lies upon the tendineous center of the thoracic diaphragmatic muscle.

Projections of the Heart Over the Anterior Thoracic Wall

  • The cardiac base is projected at the level of the upper edges of the third ribs both to the left and right of the sternum.
  • The right border is a slightly convex line that starts from the top edge of third rib, goes down about 2 cm to the right of the stemal edge, and reaches the junction point of the fifth rib cartilage behind the sternum.
  • The lower border starts at this point, runs slightly convex downwards, crosses the midline plane and ends in the fifth left intercostal space at2-3 cm. inwards from the mid-clavicular/mammary line.
  • Here is the tip of the heart/cardiac apex.
  • The left border starts at the point of cardiac apex projection, going upward convex to the side at 3-4 cm from the stemal edge and ends at the upper edge of the left third rib about 2 cm. from the sternal edge.
  • The described projections of the borders of the heart depend on the age, the constitution of the individual, the position of the body.
    • In asthenic individuals, the axis of the heart is located almost vertically - "dripping heart", whereas in hypersthenics, the axis is almost horizontal.
    • In infants and in supine position, the heart apex is shifted one intersection upwards and is located at the level the fourth intercostal space, whereas in the elderly - it is downwards, in the sixth intercostal space.
  • The heart has the shape of a three-sided pyramid.
  • The three sides, surfaces are:
    • Anterior or sterno-costal
    • Inferior or diaphragmatic
    • Two lateral surfaces
  • There are three margins distinguished on the heart's external anatomy.
  • These three margins are:
    • Acute margin
    • Obtuse margin
    • Innominate margin
  • The right atrium (RA) is located in front and to the right of the left atrium (LA).
  • The left atrium (LA) is located along the midline plane of the thoracic cavity, and the human body as a whole.
  • The right ventricle (RV) is located in front and to the right of the left venfricle (LV).

Arterial and Venous Coronary Vascular System

  • The arterial coronary vascular system originates from the aortic root.
  • It includes the left and right coronary arteries (LCA and RCA), as well as their individual/proprietary branches.
  • The first branches of the aorta are the coronary arteries themselves.
  • The left coronary artery (LCA) originates from the ostium in the left coronary sinus of Valsalva in the aortic root as left main stem or left main coronary artery (LMCA)
  • which divides early into:
    • left anterior descending (LAD), also known as anterior interventricular artery
    • circumflex artery (LCx- Left circumflexartery/branch
  • The right coronary artery (RCA) originates from the right coronary sinus of Valsalva in the aortic root, and usually ends up as posterior descending artery (PDA), also known as a posterior interventricular artery, and posterior left ventricular artery.

Left Main Coronary Artery (LMCA - left main coronary artery)

  • Left main coronary artery (LMCA) originates from the ostium in the left coronary sinus of Valsalva in the aortic root and courses in anterior and inferior direction between the left atrial appendage and the pulmonary trunk.
  • It then divides into two major arteries that have approximately equal diameter:
    • the left anterior descending artery (LAD)
    • the circumflex artery (LCx
  • There are usually no branches before the bifurcation of the left main poronary artery.
  • In some patients, the left main coronary artery (LMCA) instead of ending normally with bifurcation, ends with trifurcation in which, in addition to the typical two arterial branches
    • the left anterior descending artery (LAD)
    • the circumflex artery (LCx
    • there is a third branch - an intermediate coronary artery / branch (RIM - ramus intermedius).
  • The left main coronary artery (LMCA) is usually 10-40 mm. in length, but in some patients it may be absent as the left anterior descending artery (LAD) and the circumflex artery (LCx) originate from separate ostia, located in the sinuses of Valsalva in the aortic root.

Left Anterior Descending Coronary Artery (LAD - left anterior descending)

  • The left anterior descending coronary artery (LAD) courses forward and inferiorly.
  • It is located in the anterior interventricular groove and courses towards the cardiac apex.
  • Usually, the left anterior descending coronary artery (LAD) continues around the apex of the heart and thus provides blood supply to a part of the posterior interventricular groove, and rarely even terminates as the posterior descending artery (PDA).
  • In 4% of patients, the left anterior descending coronary artery (LAD) proximally divides and continues as two parallel-sized coronary vessels situated in the anterior interventricular groove.
  • The main branches of the LAD include:
    • Diagonal arteries (RDg - rami diagonales):
      • There are usually 2-6 in number that originate along the course of the left anterior descending artery.
      • The diagonal arteries provide blood supply to the frontal left surface of the left ventricle:
    • Septal perforators:
      • Usually 3-5 in number.
      • They branch perpendicularly from the left anterior descending coronary artery (LAD) and provide the blood supply to the anteriortwo-thirds ofthe interventricular septum.
      • The first septal perforator artery is the largest in diameter of the lumen and courses perpendicularly towards the medial papillary muscle of the tricuspid valve.
      • The first septal perforator artery is at risk during the Ross procedure as it lies immediately underneath the right ventricular outflow tract (RVOT) and the semilunar pulmonary valve.
    • Right ventricular (RV) branches.
      • They provide blood supply towards the anterior surface of the right ventricle (RV) but they are sometimes absent.
  • The LAD is divided into:
    • Proximal segment (LADp):
      • Proximal 1/3, which starts from the bifurcation / trifincation of the left main coronary artery, and ends at the level of origin of the first septal perforator artery.
    • Medial segment (LADm):
      • Middle 1/3, starting from the first septal perforator artery and ending at the level of origin of the last diagonal artery
    • Distal segment (LADd):
      • Distal 1/3, which starts from the last diagonal branch and ends with the termination of the artery

Circumflex Coronary Artary (LCx - left circumflex artery / branch)

  • The circumflex coronary artery (LCx) courses along the left atrioventricular groove and in 85-90% of the patients terminates before reaching the posterior interventricular groove.
  • In 10-L5% o