Operative Surgery and Topographic Anatomy - 2016

Content Module No. 2. Topographic Anatomy and Operative Surgery of the Regions and Organs of the Thoracic Cavity

Topic 8. Topographic Anatomy of the Thoracic Cavity. Lungs. Mediastinal Organs. Surgical Approaches to the Lungs. Pneumonectomy. Lobectomy, Segmentectomy. Topography of the Thoracic Esophagus

1. Relevance of the topic: thoracic surgery, which is rapidly evolving in conjunction with the Surgical Treatment of pulmonary, cardiac, and esophageal diseases, requires a detailed knowledge of thoracic organ topography, as well as a thorough understanding of surgical approaches and techniques required to perform operations on them.

2. Specific objectives:

1. To explain the Topographic anatomy of the Lungs.

2. To explain the topographic Anatomy of the Mediastinum.

3. To explain modern surgical techniques for Operations on the lungs, Pleura, and thoracic Esophagus.

3. Tasks for independent work in preparation for the Class.

3.1. List of key terms, parameters, and characteristics that students must master in preparation for the class:

3.2. Theoretical questions for the class:

1. Surgical anatomy of the lungs; Anatomical Features of the division of the lungs into lobes and segments.

2. Concept of the hilum and ROOT of the lung. Surgical anatomy of the root of the lung.

3. Definition of the term "mediastinum"; division of the mediastinum into superior, inferior, anterior, posterior, and middle compartments.

4. Organs located within the mediastinal compartments.

5. Surgical anatomy of the Thymus, SUPERIOR VENA CAVA, aortic arch and its branches, and phrenic nerves.

6. Surgical anatomy of the thoracic esophagus. Rationale for approaches to the esophagus at various levels. Esophagotomy. Modern possibilities of esophageal plastic surgery (esophagoplasty).

7. Surgical anatomy of the Thoracic duct, azygos and hemiazygos veins, Sympathetic trunk, Formation of the splanchnic nerves, and surgical anatomy of the aorta.

8. Anatomical and physiological rationale for surgical approaches to the lungs, Heart, and esophagus.

9. MAIN STAGES OF pneumonectomy and pulmonary resection.

3.3. Practical skills to be acquired during the class:

1. Suturing a lung wound.

2. Performing a segmental resection of the lung.

4. Course content

On anatomical specimens and cadavers, students study the shape, position, boundaries, lobar, and segmental Structure OF THE lungs. They note that the right lung features 10 segments, whereas the left lung has 9. A segment is the anatomical and surgical unit of the lung containing a tertiary bronchus, a tertiary branch of the pulmonary artery, and an intersegmental vein. When examining the lung root, they determine the topographic differences among the elements located in the right and left lungs.

In the right lung, the principal bronchus occupies the highest position, with the pulmonary artery and superior pulmonary vein lying inferiorly. In the left lung, the arrangement is the pulmonary artery, bronchus, and vein. Next, students proceed to study the mediastinum, dividing it into the anterior, superior, inferior, and posterior parts. Within the superior mediastinum, they examine the major Blood Vessels carrying blood to and from The Heart, the phrenic nerves, and the Thymus gland.

Posterior Mediastinum

The posterior mediastinum contains the esophagus, the descending aorta, the hemiazygous and azygos veins, the lower segment of the vagus nerves, and the thoracic duct.

When studying esophageal surgery, attention should be paid to its curvatures within the thoracic portion: the first is observed at the level of the 3rd thoracic vertebra; at the 4th vertebra, the esophagus assumes a median position and then deviates to the right again, while at the level of the 10th thoracic vertebra, it shifts to the left. When examining the constrictions of the thoracic esophagus, they should be identified at the level of the 4th thoracic vertebra (corresponding to the aortic arch) and at the level of the 11th thoracic vertebra, which marks the passage of the esophagus through the corresponding diaphragmatic opening.

In relation to the Thoracic Aorta, the esophagus lies initially to the right and subsequently anterior to it. The thoracic part of the esophagus is supplied by branches from the thoracic aorta, intercostal, and bronchial arteries; venous drainage is carried out via the azygos and hemiazygous veins, through the thyroid veins into the superior vena cava, and via the gastric veins into the PORTAL VEIN SYSTEM (Fig. 44).

Fig. 44. Structure of the mediastinum (schematic):

1 - superior mediastinum; 2 - heart; 3 - anterior mediastinum; 4 - middle mediastinum; 5 - posterior mediastinum.

Azygos and Hemiazygous Veins

The azygos vein lies to the right of the esophagus, and the hemiazygous vein lies to the left. The hemiazygous vein empties into the azygos vein, which in turn drains into the superior vena cava. Students can examine these veins on the anatomical specimen.

Thoracic Duct

It originates at the level of the 1st–2nd lumbar vertebrae. The duct enters the thoracic cavity through the aortic hiatus of the Diaphragm, posterior and to the right of the aorta. It then ascends between the azygos vein and the thoracic aorta, being covered anteriorly by the esophagus. At the level of the 5th thoracic vertebra, the thoracic duct gradually deviates to the left of the body's midline and proceeds toward the confluence of the left jugular and subclavian veins, forming the left venous angle.

Thoracic Aorta

The thoracic aorta is related: anteriorly, to the left bronchus and Pericardium; to the right, to the esophagus; to the left, to the mediastinal pleura; and posteriorly, to the hemiazygous vein and THE Vertebral Column. In its inferior portion, the thoracic aorta is related anteriorly to the esophagus, to the right to the azygos vein and mediastinal pleura, to the left to the mediastinal pleura, and posteriorly to the thoracic duct and vertebral column.

Vagus Nerves and Sympathetic Trunks

The right Vagus nerve enters the thoracic cavity anterior to the Subclavian Artery, where it gives off a recurrent branch that ascends into the neck, known as the recurrent laryngeal nerve. The vagus nerve proper passes behind the right bronchus and, at the level of the 5th thoracic vertebra, approaches the esophagus, lying on its posterior wall. The left vagus nerve enters the thoracic cavity between the left subclavian and left common carotid arteries, then crosses anterior to the aortic arch and similarly gives off the recurrent laryngeal nerve, which loops back toward the neck. The left vagus nerve itself joins the esophagus at the level of the 7th–8th thoracic vertebrae, positioning itself on its anterior wall.

The sympathetic trunks consist of ganglia located laterally to the bodies of the thoracic vertebrae near the heads of the Ribs. Each trunk contains 10–11 ganglia connected by interganglionic branches. Branches from the sympathetic trunks extend to the nerve plexuses of the aorta, esophagus, and lungs, forming the greater and lesser splanchnic nerves.

Suturing of Lung Wounds

Following thoracotomy with rib resection on a cadaver (or on an isolated lung specimen), students perform a lung segment resection or excise a portion of its parenchyma, followed by suturing.

5. Self-Assessment Materials:

A. Self-Assessment Tasks:

Test No. 1

A surgeon is resecting a lobe of the left lung. How many lobes are distinguished in this lung According to the International Anatomical Terminology:

a. One

b. Two

c. Three

d. Four

e. Five

Test No. 2

A metastasis spreads via blood flow within the azygos vein. Into which vein will the metastasis directly enter from this vein?

a. Right subclavian

b. Right brachiocephalic

c. Superior vena cava

d. INFERIOR VENA CAVA

e. Hemiazygos

Test No. 3

A surgeon performs a surgical approach to the lung. After dissecting which layer will they enter the pleural cavity?

a. Pectoral fascia

b. Endothoracic fascia

c. Parietal pleura

d. Visceral pleura

e. External intercostal Muscle

Test No. 4

A surgeon performs a resection of the upper lobe of the right lung. Which surgical approach is used for this Procedure?

a. Longitudinal sternotomy

b. Transverse sternotomy

c. Transverse-lateral intercostal thoracotomy

d. Lateral intercostal thoracotomy

e. Posterolateral thoracotomy

Test No. 5

During a right anterolateral thoracotomy, the surgeon identified a large vessel closely adjoining the superior aspect of the right lung root. Identify this vessel.

a. Aortic arch

в. Left pulmonary artery

c. Right pulmonary artery

d. Azygos vein

e. Hemiazygos vein

Test No. 6

A 60-year-old patient underwent a right upper lobectomy. Which segments were affected?

а. Apical, posterior, anterior

в. Lateral, medial, superior

c. Medial basal and lateral basal

d. Posterior basal, superior and inferior lingular

e. Apicoposterior

B. Self-Assessment Tasks

Task 1. A patient admitted to the surgical department has been diagnosed with anterior purulent mediastinitis. What complications are possible with this condition?

Task 2. A patient in the thoracic department underwent surgery for a thymic tumor. On the 15th postoperative day, the patient developed facial and neck puffiness, dyspnea, dull retrosternal pain, and tenderness upon Palpation above the jugular notch of the Sternum. What complication occurred in the postoperative period?

Task 3. Due to Tuberculosis of the apical segment of the right lung, the surgeon performed a right-sided pneumonectomy. Is such surgical radicalism justified?

Task 4. A patient with a diagnosed tumor of the thoracic esophagus was admitted to the thoracic department. Indicate the appropriate surgical approach to this part of the esophagus.

References

Essential

1. Operative Surgery and Topographic Anatomy; ed. by M.S. Skrypnikov. — Kyiv: Vyshcha Shkola, 2000. — P. 261-270.

2. Operative Surgery and Topographic Anatomy; ed. by M.P. Kovalsky. — Kyiv: Medytsyna, 2010. — P. 164-178.

Supplementary

1. Operative Surgery and Topographic Anatomy; ed. by K.I. Kulchitsky. — Kyiv, 1994. — P. 155-156.

2. Operative Surgery and Topographic Anatomy; ed. by G.E. Ostroverkhov. — Rostov-on-Don, 1998. — P. 435-488.

3. Toporov G.N. Clinical Anatomy of the Breast / G.N. Toporov. — Kharkiv, 2007.

4. Elizarovsky S.I. Operative Surgery and Topographic Anatomy / S.I. Elizarovsky, R.N. Kalashnikov. — M., 1979.

5. Matyushin I.F. Introduction to the Course of Operative Surgery and Topographic Anatomy / I.F. Matyushin. — Gorky, 1976.

6. Tomashuk I.P. Guide to Operative Technique for Beginner Surgeons / I.P. Tomashuk, I.I. Tomashuk. — Kyiv: European University Publishing House, 2001. — 860 p.

7. Frautschi V.H. Course of Topographic Anatomy and Operative Surgery / V.H. Frautschi. — M., 1976.