Dissection Of The Posterior Triangle Of The Neck

The supraclavicular fossa constitutes the lower part of area V. The need to include this area in the dissection has become one of the most controversial issues concerning functional and selective

Seborrheic Dermatitis Neck

Figure 4-30 Spinal accessory maneuver on the right side of the neck. (A) The nerve is exposed between the sternocleidomastoid muscle and the internal jugular vein. (B) The fibrofatty tissue lying posterior and superior to the nerve is passed beneath the nerve. sa, spinal accessory nerve; IJ, internal jugular vein; SG, submandibular gland; dm, digastric muscle; SC, sternocleidomastoid muscle; ls, levator scapulae muscle; S1, specimen from the submandibular and upper jugular area; S2, specimen from the upper spinal accessory and posterosuperior jugular area.

Figure 4-30 Spinal accessory maneuver on the right side of the neck. (A) The nerve is exposed between the sternocleidomastoid muscle and the internal jugular vein. (B) The fibrofatty tissue lying posterior and superior to the nerve is passed beneath the nerve. sa, spinal accessory nerve; IJ, internal jugular vein; SG, submandibular gland; dm, digastric muscle; SC, sternocleidomastoid muscle; ls, levator scapulae muscle; S1, specimen from the submandibular and upper jugular area; S2, specimen from the upper spinal accessory and posterosuperior jugular area.

neck dissection. We remind the reader that this controversy is beyond the scope of this book. We are not discussing the indications for the inclusion of this region in the dissection. Nor are we suggesting that this should be considered an unavoidable part of functional neck dissection for every single head and neck tumor. As should be clear to those reaching this point of reading, functional is not a surgical technique, but a concept, and the description of a complete approach should mention the removal of all nodal groups in the neck.

Figure 4-31 Artist's view of the spinal accessory maneuver on the right side of the neck. sa, spinal accessory nerve; IJ, internal jugular vein; s, specimen; sc, sternocleidomastoid muscle; sp, splenius capitis muscle.

Spinal Accessory Nerve Scm

Figure 4-32 Anterior view of the surgical field after dissection of the upper cervical regions on the right side. IJ, internal jugular vein; sa, spinal accessory nerve; ls, levator scapulae muscle; hn, hypoglossal nerve; SG, submandibular gland; dl, distal ligature of the facial vein; divided lingual veins.

Figure 4-32 Anterior view of the surgical field after dissection of the upper cervical regions on the right side. IJ, internal jugular vein; sa, spinal accessory nerve; ls, levator scapulae muscle; hn, hypoglossal nerve; SG, submandibular gland; dl, distal ligature of the facial vein; divided lingual veins.

Figure 4-33 The spinal accessory maneuver has been completed. A final cut is made anterior to the sternocleidomastoid muscle (--------), between the spinal accessory nerve and the level of Erb's point (right side). SC, sternocleidomastoid muscle retracted posteriorly; sa, spinal accessory nerve; S, specimen from the upper jugular and spinal accessory area.

Figure 4-33 The spinal accessory maneuver has been completed. A final cut is made anterior to the sternocleidomastoid muscle (--------), between the spinal accessory nerve and the level of Erb's point (right side). SC, sternocleidomastoid muscle retracted posteriorly; sa, spinal accessory nerve; S, specimen from the upper jugular and spinal accessory area.

To facilitate the exposure of the supraclavicular area, this region is approached posterior to the sternocleidomastoid muscle. The dissection begins with the removal of the fascia that still covers the posterior border of the sternocleidomastoid muscle (Fig. 4-34). It must be remembered that the fascia was dissected off the muscle up to its posterior border in a previous step of the operation (see

Erbs Point And Accessary Nerve
Figure 4-34 Dissection of the remaining fascia of the sternocleidomastoid muscle at the supraclavicular fossa (right side). SC, sternocleidomastoid muscle; F, fascia retracted laterally; PT, fibrofatty tissue of the supraclavicular fossa.

Figure 4-35 The sternocleidomastoid muscle is completely released from its surrounding fascia and is pulled medially to facilitate the dissection of the supraclavicular fossa (right side). SC, sternocleidomastoid muscle retracted medially; sn, supraclavicular branch of the cervical plexus; PT, fibrofatty tissue of the supraclavicular fossa.

Figure 4-35 The sternocleidomastoid muscle is completely released from its surrounding fascia and is pulled medially to facilitate the dissection of the supraclavicular fossa (right side). SC, sternocleidomastoid muscle retracted medially; sn, supraclavicular branch of the cervical plexus; PT, fibrofatty tissue of the supraclavicular fossa.

Dissection of the Sternocleidomastoid Muscle). The wet surgical sponges left between the anteromedial aspect of the muscle and the dissected fascia are used as a reference to complete the fascial isolation of the sternocleidomastoid muscle. Once completed, this maneuver results in a total release of the muscle from its surrounding fascia (Fig. 4-35).

The loose fibrofatty tissue of the supraclavicular fossa and the absence of well-defined dissection planes within this area make knife dissection ineffective here. Thus, for this step of the operation scissors and blunt dissection are preferred.

Some anatomical landmarks define the boundaries of the surgical field in the posterior triangle (Fig. 4-36). The inferior limit is located at the level of the clavicle. The posterior margin is clearly marked by the anterior edge of the trapezius muscle, and the upper boundary is defined by the exit of the spinal accessory nerve toward the trapezius muscle. The transverse cervical vessels and the omohyoid muscle constitute important anatomical landmarks within this area.

The sternocleidomastoid muscle is retracted anteriorly, and the external jugular vein is divided and ligated low in the neck if this was not done at a previous stage of the operation. The dissection then proceeds from the anterior border of the trapezius muscle in a medial direction including the lymphatic contents of the supraclavicular fossa. The upper margin of this area presents the greatest risk of damage to the spinal accessory nerve. The spinal accessory nerve leaves the sternocleido-mastoid muscle deep to Erb's point and descends obliquely downward and backward toward the trapezius muscle. The position of the patient's head, along with the traction exerted by the surgeon during the dissection may displace the nerve from its original course, creating a slight anterior curvature where the nerve may be inadvertently damaged. Displacement of the nerve is due to its connections with the second, third, and fourth cervical nerves. During the dissection of this region several supraclavicular branches of the cervical plexus may be found. They follow a similar course but are located superficial to the spinal accessory nerve (Fig. 4-37). Although the difference between the eleventh nerve and the supraclavicular branches is easily noticed, the novice surgeon may sometimes find this to be difficult.

Figure 4-36 Boundaries of the dissection and anatomic landmarks in the posterior triangle. C, clavicle; tm, trapezius muscle; sa, spinal accessory nerve; SC, sternocleidomastoid muscle; oh, omohyoid muscle; tc, transverse cervical artery;

Erb's point.

Figure 4-37 The spinal accessory nerve crossing the posterior triangle of the neck on the right side. Note the supraclavicular branch of the cervical plexus following a similar but more superficial course. sa, spinal accessory nerve; sn, supraclavicular branch of the cervical plexus; SC, sternocleidomastoid muscle (posterior border).

Figure 4-37 The spinal accessory nerve crossing the posterior triangle of the neck on the right side. Note the supraclavicular branch of the cervical plexus following a similar but more superficial course. sa, spinal accessory nerve; sn, supraclavicular branch of the cervical plexus; SC, sternocleidomastoid muscle (posterior border).

Figure 4-36 Boundaries of the dissection and anatomic landmarks in the posterior triangle. C, clavicle; tm, trapezius muscle; sa, spinal accessory nerve; SC, sternocleidomastoid muscle; oh, omohyoid muscle; tc, transverse cervical artery;

Erb's point.

Sternocleidomastoid LandmarksSternocleidomastoid
Figure 4-38 Dissection of the right supraclavicular fossa. tc, transverse cervical artery; OH, omohyoid muscle; AS, anterior scalene muscle; SC, sternocleidomastoid muscle; S, specimen from the supraclavicular fossa.

The omohyoid muscle is then identified, and its fascia is dissected off the muscle to be removed with the contents of the posterior triangle. The muscle may be transected at this moment if this will be required for the removal of the primary tumor; otherwise it is preserved and retracted inferiorly with a smooth blade retractor. The transverse cervical vessels are identified deep to the omohyoid muscle (Fig. 4-38). Usually they are easily dissected free from the surrounding fibrofatty tissue, displaced inferiorly, and preserved. However, the numerous variations in the branches and the exact manner of branching of the thyrocervical trunk restrain the systematization of this step (Fig. 4-39).

The deep layer of the cervical fascia over the levator scapulae and scalene muscles is now visible (Fig. 4-38). The brachial plexus is easily identified as it appears between the anterior and middle scalene. Staying superficial to the scalene fascia prevents injuring the brachial plexus and the phrenic nerve (Fig. 4-40).

The dissection is continued medially until it reaches the level of the anterior border of the sternocleidomastoid muscle. The muscle is then pulled laterally with retractors and the contents of the supraclavicular fossa are passed underneath to meet the tissue previously dissected from the upper half of the neck. The sternocleidomastoid muscle is then retracted posteriorly, and the dissection continues anterior to the muscle toward the carotid sheath.

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