Note: last updated before 2013

See more commonly used submental flap and Submental flap for oral cavity defect - Clinical case example

GENERAL CONSIDERATIONS

1. Indications
   1. The platysma flap may be used to close defects on the lower face, buccal mucosa, and floor of mouth.
   2. In selected cases, the flap will extend to the oropharynx; however, depending on the body habitus of the patient, closure of defects in the oropharynx may require excessive tension on the flap.
   3. The flap is ideally suited for reconstruction of deep chin and low anterior cheek defects in patients not requiring neck dissection. The color match is good with facial skin. When used to resurface these areas, a dual blood supply including the submental and superior thyroid arteries may be preserved (see pertinent anatomy section).
2. Contraindications
   1. Prior radiotherapy to the neck will significantly compromise the viability of the flap.
   2. The main blood supply to the flap derives from the submental branch of the facial artery and a cutaneous branch of the superior thyroid artery. Neck dissections that interrupt these vessels are a relative contraindication to the use of this flap.
   3. The flap is relatively thin, and the need for tissue bulk is a contraindication to the use of this flap.
   4. Flaps as large as 7 x 10 cm may be harvested in selected individuals; however, if the defect size is larger than 5 x 7 cm, an alternative reconstructive method should be considered.
   5. Patients with extremely thin skin and a poorly-developed platysma muscle are not ideal candidates for this procedure.
   6. The flap should not be used if the sternocleidomastoid muscle will be removed as a part of the planned neck surgery.
3. Pertinent Anatomy
   1. The platysma muscle is a remnant of the panniculus carnosis within the subcutaneous tissue of the neck. The muscle itself lies superficial to the muscular fascial sheath of the neck.
   2. Blood vessels from the muscle to the overlying skin are not true musculocutaneous perforators, and the muscle does not have a true axial blood supply. The muscle and overlying skin receive blood from a variety of sources including the submental artery, branches of the proximal facial artery, postauricular artery, occipital artery, terminal cutaneous branches of the superior thyroid artery, superficial cervical artery, and transverse cervical artery.
   3. The most important blood supply to the flap when it is used for intraoral and lower facial reconstruction are the submental branch of the facial artery and the superior thyroid artery. Blood supply to the muscle and lower neck skin from the superior thyroid artery is derived from a branch that courses in the anterior muscular fascia of the sternocleidomastoid and gives off several cutaneous branches. The mandibular and cervical branches of the facial nerve as well as the anterior and external jugular veins course immediately deep to the muscle.

PREOPERATIVE PREPARATION

1. Evaluation
   1. A careful history and physical examination should be undertaken to determine that there has been no prior neck surgery or radiation therapy that would contraindicate the flap.
   2. The external jugular vein and anterior neck veins will be elevated with the flap. The presence and location of these veins should be noted.
   3. Because the flap is not a "musculocutaneous flap," the vascularity to the skin of the flap does not depend on the degree of development of the platysma muscle. In patients with thin platysma muscles, however, the flap may be technically difficult to raise. The size and development of the platysma can be estimated by letting patients tense the muscle and observing the neck.
2. Potential Complications
   1. Flap failure and loss of the cutaneous paddle: This is not an extremely robust flap with a rich blood supply. Despite apparent preservation of the blood supply, if a neck dissection is performed, the risk of skin necrosis is significant. If the continuity of the facial artery between its origin and the submental branch is disrupted, the blood supply will be tenuous.
   2. Injury to the mandibular branch of the facial nerve
   3. Distortion of the contour of the jaw line will occur to some degree with the use of this flap and patients should be aware of that.

NURSING CONSIDERATIONS

1. Room Setup
   1. See Free Flap Room Setup
2. Instrumentation and Equipment
   1. Standard
      1. Major Instrument Tray 1, Otolaryngology
      2. Major Instrument Tray 2, Otolaryngology
      3. Bipolar Forceps Trays
3. Medications (specific to nursing)
   1. 1% lidocaine with 1:1000 epinephrine
   2. Antibiotic ointment to incision
4. Prep and Drape
   1. Standard prep, 10% providone iodine
   2. Drape
      1. Head drape
      2. Towels to square off operative site including entire face, neck, and down onto the chest to the nipples
      3. Split sheet
5. Drains and Dressings
   1. 7 mm or 10 mm x 2 flat drains
6. Special Considerations
   1. The patient should be prepped bilaterally including the entire face, neck, and down onto the chest to the nipples.

ANESTHESIA CONSIDERATIONS

1. General
   1. The patient should not be paralyzed until after the mandibular branch of the facial nerve that will be required for the particular use of the flap is identified.
   2. The patient is positioned supine on a Mayfield headrest and, in most cases, the bed will be turned 180° from the anesthesiologist.
2. Specific
   1. In the vast majority of cases, the surgery is done under general anesthesia. For small skin defects, the flap could be raised with the patient under IV sedation.

OPERATIVE PROCEDURE

1. The terminal cutaneous blood vessels to the platysma may be delicate. The surgeon's use of loupe magnification during elevation of the flap is useful.
2. The anticipated skin paddle should be outlined in the lower lateral neck. The lower margin of this skin paddle should not extend below the clavicle.
3. The method of flap elevation will vary depending on the indication for flap use.
4. If an external skin defect is to be covered, the skin over the platysma muscle between the paddle and defect may be elevated to create a tunnel or skin incision between the defect and skin paddle and the skin reflected back off the platysma on either side. Mobilizing the flap through a long skin tunnel is difficult. If an intraoral defect is to be closed, a large platysma skin flap may be raised with the inferior margin of the skin paddle defining the most distal extent. The upper skin paddle incision is not made until after it is determined that the paddle will cover the defect.
5. The skin overlying the platysma is elevated in a plane above the muscle, just into the subcutaneous tissue. The muscle fibers should retain some connective tissue covering.
6. The inferior margin of the muscle is divided distal to the skin paddle.
7. The muscle and skin paddle are mobilized toward the defect by elevation of the platysma in an inferior to superior direction.
8. The plane of elevation should include the fascia of the sternocleidomastoid, as well as the anterior and external jugular veins. Inclusion of these veins that are left intact superiorly adds to venous drainage of the flap.
9. By elevation of the fascia of the sternocleidomastoid from lateral to medial, the superior thyroid contribution should be left intact. This will create a rotation point for the flap that is relatively low, and additional length can be obtained by bringing the fascia overlying the strap muscles up with the anterior jugular veins.
10. The muscle may be detached along its posterior and postero-superior margins. Care should be taken not to injure the mandibular branch or external jugular vein when this is done.
11. Mobilization of the flap may require division of the superior thyroid contribution. In such a case, every effort should be made to keep the base of the flap as wide as possible.
12. The neck skin is closed in two layers. Mobilization of upper chest skin will facilitate closure of the skin paddle donor site.
13. Two 10 mm fully-perforated suction drains are placed. One should lie parallel to the sternocleidomastoid in the groove anterior to it, and the other should lie posterior to it.

POSTOPERATIVE CARE

1. Drains are removed when the output is less than 30 ml per day.
2. Tension on the flap is minimized if the patient's head is turned toward the donor side. This should be reinforced in the postoperative orders and accomplished with pillows or sandbags.

REFERENCES

Coleman JJ, Jurkiewicz MJ, Nahai F, Mathes SJ. The platysma musculocutaneous flap: experience with 24 cases. Plast Reconst Surg. 1983;72:315-321.

Esclamado RM, Burkey BB, Carroll WR, Bradford CR. The platysma myocutaneous flap indications and caveats. Arch Otolaryngol Head Neck Surg. 1994;120:32-35.

Hurwitz DJ, Rabson JA, Futrell JW. The anatomic basis for the platysma skin flap. Plast Reconst Surg. 1983;72:302-312.