Designing a bipedicled sternocleidomastoid muscle flap for parotidectomy contour deformities.

The bipedicled sternocleidomastoid (SCM) muscle flap is useful for the reconstruction of contour deformities secondary to parotidectomy defects. Proper design of this flap allows for the total reconstruction of parotid tail defects. We describe the design and utility of this flap as a simple, reproducible, and aesthetically pleasing method of reconstructing posterior facial concave deformities that occur as a result of superficial parotidectomy.

The posterior limb of the cervical portion of the modified Blair incision is undermined to obtain full access to the SCM muscle (figure 1, A). An incision is made along the rostral-caudal axis of the muscle, splitting the SCM into vertical halves (figure 1, B). This incision is taken down to the depth level of the transverse raphe (figure 1, C). Above the level of the posterior belly of the digastric muscle, this incision can be made with impunity. Below the digastric muscle, the spinal accessory nerve is more of a consideration. This incision is a relaxing incision, and it can be extended as far inferiorly as necessary to achieve a tension-free advancement. Lower parotid defects rarely require an extension more than 2 or 3 cm below the inferior margin of the posterior belly of the digastric muscle. Small muscular arteries may be encountered as the raphe is approached. If so, bleeding can be controlled with bipolar cautery to prevent postoperative hematoma formation. Sacrificing these small arteries will not compromise the vascular integrity of the flap.

Once the relaxing incision is made, the anterior border of the muscle is advanced medially into the parotid defect in an accordion fashion (figure 2). The SCM muscle and its investing deep cervical fascia are then sutured to the renmant fascia parotideomasseterica with interrupted 3-0 chromic or Vicryl sutures. The superior and inferior attachments of the SCM remain intact, thus maintaining a minimum of two vascular pedicles as well as maintaining the functionality of the muscle.

Many techniques have been used to reconstruct parotid defects. The bipedicled SCM muscle flap's unique utility is drawn from its recruitment of locally well-vascularized muscle tissue that has not been denervated, which protects against muscle atrophy. The muscle is fanned, which prevents a complete transposition defect because the muscle bulk is split between the harvest site and the defect in a 1:1 ratio. This procedure, which can be easily performed without the need for advanced surgical training, results in excellent cosmesis and functional reconstruction with little or no harvest site morbidity (figure 3).

Suggested reading

Osborne RF, Tan JW, Hamilton JS, Calcaterra TC. Bipedicled sternocleidomastoid muscle flap for reconstruction of tail of parotid defects. Laryngoscope 2004;114:2045-7.

Jason Hamilton, MD; Sofia Avitia, MD; Ryan F. Osborne, MD, FACS 

From the Osborne Head and Neck Institute (Dr. Hamilton, Dr. Avitia, and Dr. Osborne), and the Head and Neck Cancer Center, Cedars-Sinai Medical Center (Dr. Osborne), Los Angeles.