Operative Surgery and Topographic Anatomy - 2016

Content Module No. 1. Introduction to Topographic Anatomy and Operative Surgery. Topographic Anatomy and Operative Surgery of the Head and Neck Regions

Topic 2. Topographic Anatomy of the Neurocranium. Boundaries, External Landmarks. Head Shape, Age-Related Features. Division into Regions: Frontoparietooccipital, Temporal, Mastoid. Layers of the Scalp, Fascial Spaces, Blood Supply, Innervation, and Lymphatic Drainage. Primary Surgical Debridement of Cranial Wounds. Antrotomy

1. Relevance of the Topic

Soft tissue INJURIES OF THE HEAD, cranial bone fractures, hematomas of various localizations, penetrating and non-penetrating wounds of the cranial vault, and tumors are quite common. Knowledge of the Anatomical and physiological Features of the soft Tissues in the frontoparietooccipital, temporal, and mastoid regions is essential for the proper drainage of hematomas, abscesses, and phlegmons, as well as for performing primary surgical debridement of penetrating and non-penetrating neurocranial wounds.

2. Specific Objectives

1. Explain the Topography of the Vessels and nerves of the scalp and their localization zones to administer regional anesthesia and design flaps during surgical interventions.

2. Analyze the layered tissue Structure OF THE cranial vault.

3. Analyze the pathways of spread for phlegmons, purulent edemas, and hematomas within the scalp.

4. Explain the connections between the subcutaneous Veins OF THE neurocranium and the Dural Venous Sinuses.

5. Explain the Procedure for performing primary surgical debridement of neurocranial wounds.

6. Explain the techniques for arresting Hemorrhage from subcutaneous vessels, cranial bones, Meninges, and venous sinuses.

7. Explain the boundaries of MacEwen's (Chiene's / Editor's note: translating Шипо as MacEwen's / mastoid triangle) trepanation triangle.

8. Explain the technical Procedures of antrotomy.

3. Tasks for Independent Work in Preparation for the Class

3.1. List of key terms, parameters, and characteristics to be mastered by the student in preparation for the class

3.2. Theoretical Questions for the Class

1. BOUNDARIES OF THE head. Neurocranium and viscerocranium. Their subdivision into regions.

2. Regions of the cranial vault and their boundaries.

3. Layers of the frontoparietooccipital region.

4. Vessels and NERVES OF THE frontoparietooccipital region.

5. Boundaries of the temporal region.

6. Layers of the temporal region.

7. Vessels and nerves of the temporal region.

8. Fascial spaces of the temporal region.

9. Boundaries of the mastoid region.

10. Layers of the mastoid region.

11. Boundaries of MacEwen's (Chassaignac's) mastoid triangle and its significance in antrotomy.

12. Technique for primary surgical debridement of cranial wounds.

13. Technique for performing antrotomy.

3.3. Practical skills acquired during the session

1. Master the layered dissection of the regions under study.

2. Based on the knowledge of subaponeurotic and subperiosteal spaces, identify subaponeurotic and subperiosteal abscesses and hematomas of the scalp.

3. Anticipate potential pathways for the spread of purulent infection from the fascial spaces of the temporal region.

4. Outline the boundaries of MacEwen's mastoid triangle and recognize potential complications during antrotomy.

5. Perform primary surgical debridement of cranial wounds and mastoidectomy.

4. Topic Content

Frontoparietooccipital Region

At the beginning of the session, following a brief verbal review of the boundaries and layered structure of the frontoparietooccipital region, students proceed to independent dissection of this area (Fig. 12).

Fig. 12. Layers of the cranial vault in a coronal section through the frontoparietooccipital region (diagram based on S.N. Delitsin, with modifications):

1 - Skin; 2 - subcutaneous tissue; 3 - epicranial aponeurosis (galea aponeurotica); 4 - diploic vein; 5 - subaponeurotic space; 6 - periosteum; 7 - subperiosteal space; 8 - arachnoid granulations (Pacchian bodies); 9 - Blood accumulated in the extradural space due to injury of the middle meningeal artery (10); 11 - dura mater; 12 - arachnoid mater; 13 - CEREBROSPINAL FLUID of the subarachnoid space; 14 - pia mater; 15 - Cerebral Cortex; 16 - falx cerebri; 17 - superior sagittal sinus of the dura mater; 18 - cerebral veins; 19 - artery and vein of the dura mater; 20 - extradural space; 21 - inner ("vitreous") table of the Parietal bone; 22 - spongy substance (diploe); 23 - outer table of the parietal bone; 24 - emissary vein; 25 - subcutaneous vessels; 26 - Connective Tissue septa connecting the skin to the epicranial aponeurosis.

The shape of a hypothetical flap is outlined in the frontal, parietal, or occipital region of the head. It is important to emphasize that the fashioned flap must have its base directed inferiorly. This ensures adequate Blood supply to the flap and its subsequent engraftment.

Students reflect the skin and subcutaneous tissue along with the aponeurosis. Attention is drawn to the attachment between the skin and the aponeurosis provided by connective tissue strands extending from the skin to the aponeurosis. The relationship between the walls of subcutaneous Blood Vessels and these connective tissue strands is identified, along with the potential for prolonged hemorrhage from the vessels. The instructor characterizes scalp avulsion injuries. After fashioning the aponeurotic flap, students insert a Kocher probe between the aponeurosis and the periosteum, thereby verifying the laxity of the subaponeurotic space. Next, the periosteum of the cranial vault is incised.

Due to the presence of a loose subperiosteal tissue layer, the periosteum is easily detached from the bone.

On a sagittal section of the Skull, students examine the Bone Structure. It is important to emphasize The Significance of the thickness of the inner table in the occurrence of cranial bone injuries during trauma to the neurocranium. During the dissection of the frontoparietooccipital region, attention should be paid to the radial orientation of the neurovascular bundles.

Summarizing the Discussion on the layered structure of the scalp tissues, it should be noted that each layer is associated with a fascial/cellular space: skin — subcutaneous tissue; epicranial aponeurosis (galea aponeurotica) — subaponeurotic space; periosteum — subperiosteal space. The first three layers are tightly interconnected by vertical connective tissue septa. The vault bones consist of outer and inner tables, with diploic tissue (diploe) situated between them.

Blood supply to the frontoparietooccipital region is provided by the following Arteries: supraorbital, supratrochlear, superficial temporal artery and its branches (frontal and parietal), posterior auricular, and occipital. Innervation: supraorbital, supratrochlear, auriculotemporal, great auricular, lesser occipital, and greater occipital nerves.

Temporal Region

A Tongue-shaped flap 2.5 cm wide and 4 cm long is outlined in the temporal region. First, the students separate the skin from the deeper tissues. They note the absence of a distinct epicranial aponeurosis in this area, as the latter is thinned out and appears as the superficial Fascia of the temporal region. After reflecting the skin along with the subcutaneous tissue and superficial fascia, the students expose the temporal fascia, separate its superficial and deep layers, and verify the presence of a closed fascial space between them above the zygomatic arch. Next, the Deep Layer of the temporal fascia is incised, and a Kocher probe is passed beneath the zygomatic arch to confirm The connection between the subaponeurotic space and the buccal fat pad. After separating the subfascial tissue, the students outline a tongue-shaped flap of the temporalis Muscle and reflect it downward. On the posterior surface of the temporalis muscle, the students dissect the Branches of the deep temporal artery and the corresponding nerve. Between the muscle and the periosteum, they expose a deep layer of loose connective tissue of the temporal region, after which the periosteum is incised.

On a bone specimen, the students study The structure of the squamous part of the Temporal bone. They examine the groove for the middle meningeal artery and discuss the risk of injuring this vessel during trauma to the temporal bone.

Blood supply to the region: the superficial temporal artery and its branches, as well as the deep temporal branches of the maxillary artery.

Innervation: the auriculotemporal and facial nerves, along with the deep temporal branches of the mandibular nerve.

Mastoid region

On a bone specimen, the students examine the boundaries of the region corresponding to the mastoid process. They then proceed to the layered dissection of the mastoid region. They observe that the skin in this area is thin and firmly attached to the underlying aponeurosis.

During the dissection, it is important to note that the periosteum is tightly adherent to the bone. By sawing through the mastoid process, the students study its structure, noting potential pneumatic or sclerotic types of cellular architecture, and identify the largest Cell, known as the mastoid antrum.

On the bone specimen, the students examine the boundaries of MacEwen's (Schchipov's) triangle, within which trepanation of the mastoid process—antrotomy—should be performed (Fig. 13).

Fig. 13. Trepanation of the mastoid process:

A - Schwartz's soft tissue incision line; B - diagram of MacEwen's triangle on a skeletonized process: 1 - middle cranial fossa; 2 - main air cell of the process; 3 - sigmoid venous sinus; 4 - Facial Nerve; C - trepanation technique.

Primary surgical debridement of craniocerebral wounds

The indication for primary surgical debridement of craniocerebral wounds is a traumatic Brain injury. It is emphasized that the goal of this procedure is to convert an infected wound into a non-infected one. The criteria for penetrating and non-penetrating craniocerebral wounds are established: injuries involving the dura mater are classified as penetrating, while those where it remains intact are non-penetrating. The main steps of primary surgical debridement of craniocerebral wounds are as follows:

✵ removal of foreign bodies and bone fragments, application of antiseptics, and anesthesia;

✵ layered excision of non-viable wound edges within healthy tissue margins;

✵ thorough hemostasis;

✵ exploration of the wound base.

Only bone fragments that are not secured by the periosteum should be removed, along with any foreign bodies.

During the layered debridement of craniocerebral wounds, special attention is paid to the condition of the dura mater. If it is intact, pulsates, and shows no signs of subdural hematoma, it should not be incised. At the end of the procedure, sutures are placed in the aponeurosis; the skin is either left unsutured or approximated with interrupted loose sutures.

In the case of a penetrating wound, the dura mater is incised with a U-shaped cut, and bone fragments, foreign bodies, blood clots, and other debris are removed from the brain tissue.

Crushed brain tissue (detritus) and small bone fragments embedded within it are washed out of the wound using a stream of saline via a rubber bulb syringe. After meticulous hemostasis, the dura mater is sutured. If primary closure is impossible (due to significant dural defects), the dura is left unclosed, loose sutures are placed in the aponeurosis, the skin is usually also closed with loose sutures, and rubber drains are left in the corners of the wound for 1–2 days.

5. Self-assessment Materials

A. Self-assessment tasks

Test No. 1

A victim presents with a lacerated wound in the anterior fronto-parieto-occipital region. What corresponds to the anterior boundary of this region?

a. Superior nuchal line

b. Nasion and superciliary arches

c. Superior temporal line

d. Inferior temporal line

e. Suture between the parietal and frontal bones.

Test No. 2

A patient presents with a 2x2 cm abscess in the fronto-parieto-occipital region. In which layer is the inflammatory process localized in this case?

a. Intradermally

b. In the subcutaneous tissue

c. In the subaponeurotic cellular space

d. In the subaponeurotic tissue

e. In the subperiosteal tissue.

Test No. 3

A physician evaluated a patient's pulse on the superficial temporal artery. Where is the pulsation point of this artery located?

a. 1 fingerbreadth anterior to the tragus of the ear

b. 1 fingerbreadth posterior to the ear

c. 2 cm posterior to the mastoid process

d. Along the anterior border of the masseter muscle

e. Above the ear.

Test No. 4

A patient has an abscess in the left parietal region. The surgeon is about to drain the abscess. Which incision would be the most anatomically justified and least traumatic in this case?

a. Transverse

b. Longitudinal

c. Radial toward the vertex

d. Radial toward the tragus of the ear

e. Arched

B. Self-Assessment Questions

Problem 1. Patient M. was brought by an ambulance complaining of a headache and Swelling in the cranial vault region. The patient slipped and fell 2 hours ago. Upon examination, mobile swelling was revealed, bounded anteriorly by the margin of the Orbit, posteriorly by the superior nuchal line, and laterally by the superior temporal line. Diagnosis: hematoma of the cranial vault. In which fascial space (layer) is the hemorrhage located?

Problem 2. A patient with a chop wound in the parietal region is experiencing massive arterial bleeding. Despite wound Treatment with hydrogen peroxide and the application of a pressure bandage, the bleeding has not stopped. What is the cause of the massive bleeding, and how can it be stopped?

Problem 3. During the primary surgical debridement of a non-penetrating wound in the frontal region, the surgeon decided to excise the soft tissues 1 cm from the wound edges within healthy tissue boundaries. Is this correct?

Problem 4. While performing an antrotomy, the surgeon went beyond the posterior border of the suprameatal triangle (MacEwen's triangle). Severe bleeding occurred. What is the source of the bleeding?

Problem 5. During an antrotomy, the patient developed facial muscle paralysis on the side of the surgical intervention. What is the cause of this complication?

References

Basic

1. Operative Surgery and Topographic Anatomy; ed. by M.S. Skrypnykov. — K.: Vyshcha Shkola, 2000. — pp. 37-46.

2. Operative Surgery and Topographic Anatomy; ed. by M.P. Kovalskyi. — Kyiv: Medytsyna, 2010. — pp. 47-58.

Supplementary

1. Kovanov V.V. Operative Surgery and Topographic Anatomy / V.V. Kovanov. — M.: Meditsina, 1978. — pp. 83-89.

2. Operative Surgery and Topographic Anatomy; ed. by K.I. Kulchytskyi. — K.: Vyshcha Shkola, 1994. — pp. 33-39.

3. Operative Surgery and Topographic Anatomy; ed. by G.E. Ostroverkhov. — Rostov-on-Don, 1998. — pp. 313-323.

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

5. Vishnevsky A.V. Local Anesthesia by the Method of Creeping Infiltration / A.V. Vishnevsky. — M., 1956.

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

7. Tomashuk I.P. Guide to Operative Technique for Beginning Surgeons / I.P. Tomashuk, I.I. Tomashuk. — K.: Publishing House of the European University, 2001. — 860 p.

8. Bekov D.B. Atlas of the Venous System of the Human Brain / D.B. Bekov. — M., 1965.

9. Zolotko Yu.L. Topographic Atlas of the Head / Yu.L. Zolotko. — M., 1976, part.

10. Zolotareva T.V. Surgical anatomy of the Head / T.V. Zolotareva, G.N. Toporov. — M., 1968.