Neck Rejuvenation

Anatomy and Physiology

Understanding the superficial anatomy of the neck is critical to not only selecting and planning the appropriate procedure but also documenting physical findings. The most commonly used system of categorizing aging neck changes is the Dedo classification, which follows:[2]

1. Normal
2. Skin laxity only
3. Neck adiposity
4. Platysmal banding
5. Retrognathia 
6. Low lying hyoid

Each successive category is more difficult to address than the last, with skin laxity easily reduced with a conservative neck lift. Underneath the skin, there is subdermal fat, which can be removed with liposuction, deoxycholic acid injection, and cryotherapy; liposuction is commonly combined with surgical neck lifting in the operating room. Beneath the subdermal fat lies the thin sheet of the platysma muscle. This muscle is contiguous with the mimetic muscles and superficial musculoaponeurotic system (SMAS) of the face; it produces the vertical bands seen in an aging neck when the medial borders dehisce away from each other and move laterally. Suturing the medial borders of the platysma back together during a platysmaplasty both helps to reduce the appearance of vertical bands and provides a strong sling that can be suspended laterally in order to restore a more youthful cervicomental angle during a neck lift. In the case of severe vertical banding, the platysma may be divided transversely at the level of the hyoid bone to further reduce the bands and redefine the cervicomental angle.[3]

Subplatysmal fat occupies the space between the platysma superficially and the deeper strap muscles that cover the larynx; this fat may be excised directly, if necessary, but should not be addressed blindly with liposuction due to the danger of injuring nearby vessels, nerves, and viscera. Retrognathia or microgenia and unfavorable hyoid position are important to recognize preoperatively because they will both contribute to a poor surgical outcome, but addressing them is not a typical part of neck rejuvenation procedures.

In addition to the structures referred to in the Dedo classification system, it is important to be aware of several other factors when considering cervical procedures. The submandibular glands may be prominent or ptotic, the appearance of which may be unpleasantly exacerbated by tightening the neck surgically or reducing submental adiposity; in some cases, reduction or removal of the glands may be considered.[4]

Evaluating the skin quality is important as well, given that the neck skin often shows similar signs of sun damage to those seen on the face, but the neck skin is thinner and has fewer dermal appendages, making it less resilient to resurfacing efforts. While most of the critical structures in the neck are located deeply, such as the carotid artery, larynx, internal jugular vein, and thyroid gland, there are some nerves and vessels at risk during cervical rhytidectomy. The marginal mandibular branch of the facial nerve is often found 1 to 2 cm inferior to the inferior border of the mandible posteriorly but crosses the mandible anteriorly on its course back up into the face to innervate the depressors of the lower lip. The cervical branch of the facial nerve innevates the platysma and is not as commonly injured as the marginal mandibular branch, but because the two nerves occasional split from a common trunk, the cervical branch may also contribute innervation to the lower lip depressors; therefore, injury to this branch may also result in weakness of the lower lip.[5][6]

In the face proper, this nerve branch typically runs along with or even wraps around the distal aspect of the facial vein; damage to the nerve results in the inability to depress the lower lip and causes an asymmetric smile. More commonly injured, however, is the great auricular nerve, which lies deep and lateral to the platysma and courses over the sternocleidomastoid between Erb's point and the inferior aspect of the auricle. Roughly 1 cm anterior to this nerve lies the external jugular vein, which is also at risk for injury during rhytidectomy.[2]

Indications

Because there are numerous physical examination findings and specific chief complaints with respect to the aging neck, a discussion of indications for intervention should focus on the specific anatomical changes encountered in an individual patient. For example, skin laxity is easily addressed with a neck lift procedure, but if the skin appears wrinkled in the absence of significant redundancy, CO2 or Er:YAG laser resurfacing with conservative settings may be a more appropriate treatment modality.

Similarly, if mild platysmal banding is the only complaint, injection of 10 to 30 units of onabotulinumtoxin, or its equivalent, per side may correct the issue; however, if vertical platysmal bands and skin redundancy are present together, a plastymaplasty can address the banding during the rhytidectomy for skin laxity. Submental liposuction can be performed for excess adiposity on its own or in conjunction with rhytidectomy; cryotherapy, radiofrequency ablation, and deoxycholic acid injections can also be used to reduce submental fat, typically as stand-alone procedures.

Contraindications

Contraindications for cosmetic procedures of the neck include poor health that may increase the risk of cardiopulmonary complications under general anesthesia, unreasonable expectations for outcomes, and any conditions liable to result in postoperative complications.

More specifically, patients with bleeding disorders or a requirement for ongoing anticoagulant therapy are more likely to develop a hematoma after rhytidectomy. Patients with poorly-controlled diabetes, vasculitides, recent smoking history, a history of scarring or poor wound healing, or immunomodulatory therapy may be at risk for delayed or suboptimal wound healing that may cause infection, scarring, or skin necrosis.[7]

Equipment

Equipment required for a surgical neck lift typically includes a skin marker, local anesthetic or tumescent solution, #15 blade scalpel, retractor and light source, facelift scissors, needle drivers, electrocautery, suction, and sutures for both soft tissue suspension and skin closure. Heavy 2-0 or 3-0 polyester, polydioxanone, or polyglactin sutures work well for reapproximating the medial borders of the platysma. Smaller 4-0, 5-0, and 6-0 sutures are used for layered skin closure. A Barton-style dressing with ice packs is typically applied at the conclusion of the procedure.

Skin resurfacing can be accomplished with numerous different systems, including carbon dioxide, diode, and erbium-doped yttrium-aluminum-garnet lasers, as well as broadband or intense pulsed light. If these systems are unavailable, a superficial chemical peel may also produce the desired effect.

Other modalities, such as cryoablation and radiofrequency ablation, may also be used to reduce excess adiposity, and these procedures require specialized equipment to perform.

Injection of botulinum toxin and deoxycholic acid requires minimal equipment: sterile saline, hypodermic needles, and a syringe.

Personnel

Surgical interventions require an anesthesia provider, an operating room circulator nurse, a technologist, a surgeon, and potentially an additional surgical assistant, such as an RN first-assist or a physician assistant.

Non-surgical treatments, like injections, can often be performed by a surgeon, a non-surgeon physician, such as a dermatologist, or a non-physician, such as a physician assistant or nurse.

Preparation

The most important aspect of preparation for any cosmetic procedure is patient counseling and expectation management. Treatment, surgical or otherwise, should not begin until the surgeon or other healthcare provider feels that the patient's goals and expectations are consistent with anticipated outcomes. Additionally, surgical patients should ideally temporarily discontinue anticoagulant therapy and quit smoking, if applicable.

Facial and great auricular nerve function should be evaluated and documented prior to rhytidectomy. Having preoperative photographs of the patient posted in the operating room for reference during the case is also helpful. The patient's jowls and platysmal bands should be marked while the patient is sitting upright, and the nurse performing the surgical scrub should avoid smearing or removing the marks.

Regardless of whether the plan is for general anesthesia or not, injection of local anesthetic or tumescent solution will help to lower the analgesic requirement and aid hemostasis. Intravenous steroids will decrease edema and nausea in the immediate postoperative period, facilitating the patient's discharge home.[8]

Technique or Treatment

Submentoplasty [3][9][10]

A skin incision is marked in a transverse submental crease, centered and roughly 3 cm in length. A #15 blade is then used to make a single stab incision in the center of the planned incision as well as two more, 1 to 2 mm inferior to the attachment of each ear lobule. A 2 to 3 mm liposuction cannula on a 10 cc syringe is then inserted through the stab incisions, the submental one first, and subsequently the lateral ones. Care should be taken to face the opening of the cannula away from the dermis so as not to cause postoperative texture irregularities or disrupt the blood supply to the skin.

Dry passes are made with the cannula under the skin to create tunnels prior to applying suction. The assistant should retract the skin away from the surgeon to create appropriate counter tension. The cannula's tip should be just visibly tenting the skin in order to ensure the liposuction remains sufficiently superficial to avoid damaging blood vessels or other important structures. The area of cannula dissection should remain superior to the hyoid and inferior to the border of the mandible, in order to avoid injury to the marginal mandibular nerve and larynx. Maintaining this plane will also facilitate later flap elevation.

The submental incision is then made, allowing dissection to enter the subcutaneous plane. The skin flap is retracted with a double prong skin hook toward the surgeon while the assistant provides counter tension. Facelift scissors, such as Gorney-Freeman or Goldman-Fox scissors, are used to dissect in a subcutaneous plane from the submentum past the level of the hyoid. As the dissection proceeds inferiorly, a facelift retractor can be exchanged for the skin hook. Once the platysma borders are identified, additional lipectomy may be performed in between the muscle bellies, if necessary.

A plane is developed along the undersurface of the platysma and carried 1 to 2 cm laterally. Fat on the deep surface may need to be removed; however, excessive fat removal in this area can lead to a cobra neck deformity. The fat that has been removed should be kept in saline in the event it needs to be replaced. If the cervicomental angle is extremely obtuse, the surgeon can dissect the platysma's medial border at the level of the hyoid and divide it transversely. The medial platysmal borders are then approximated with 3 or 4 buried, interrupted sutures between the hyoid and the mentum.

Neck Lift [10][11]

Attention is now turned to the facial incisions. An abbreviated Blair incision is marked starting anterior to the lobule and proceeding onto the posterior surface of the auricle, and then posteriorly and inferiorly into the hairline. The incision is made with a #15 blade through the dermis and into a subcutaneous plane. Countertension should be applied on the neck, and the flap developed using facelift scissors. Castañares scissors are particularly helpful to divide the tough soft tissue attachments over the mastoid. Elevation then continues anteriorly to join the submental dissection. The flap is subdermal/supraplatysmal; therefore, the great auricular nerve and external jugular vein should not be at risk if the correct plane is maintained.

The surgeon places two non-absorbable sutures as buried half mattresses between the lateral border of the platysma and the mastoid periosteum. The vector of pull will be roughly parallel to the posterior border of the helix. The first suture is placed superiorly and the second more inferiorly. After hemostasis is obtained, the skin flaps are tailored to eliminate redundant skin, and the wounds are closed in layers over a drain, taking care to avoid excessive tension on the suture lines, particularly inferior to the lobules.

Antibiotic ointment and a compressive head and neck dressing are applied.

Laser Skin Resurfacing

Settings will vary by device, but it should be remembered that the combined thickness of the epidermis and dermis in the neck is just over 0.25 mm on average, whereas the skin of the cheek is over 1 mm in depth. This, combined with the lower concentration of dermal appendages, means that healing may be slower and less energy should be delivered than when performing facial resurfacing. Fractionated delivery of the laser may be preferable to fully ablative settings, if available, and resurfacing should stop when the papillary dermis is reached, indicated by the presence of pinpoint bleeding and a subtle change in skin color toward a more yellow hue. If performing laser resurfacing under the same anesthetic as a surgical neck lift, using even more conservative settings may be prudent.

Botulinum Toxin Injection

The platysmal bands are visualized with the patient in an upright position, and aliquots of 5 units of botulinum toxin are injected with a fine gauge hypodermic needle (30 or greater) in a vertical line along the medial border of the platysma. Typically, 3 to 6 injection sites are required on each side. The injections will take 1 to 2 weeks to reach their maximum effect and will last for 3 to 4 months. Repeat as necessary.

Other Modalities

The deoxycholic acid injection may be performed roughly every six weeks, but not usually more often than every 4, given the edema that typically follows injections. Cryoablation is also typically performed at roughly one-month intervals until the desired effect is reached; radiofrequency ablation is ideally performed as a single treatment only.

Complications

While the most common adverse outcome associated with any cosmetic procedure is dissatisfaction, whether because the effect was insufficient or unexpected, there are several other potential complications that should be avoided if possible. With respect to surgery, hematomas and seromas are common in the early postoperative period, especially in hypertensive patients and patients on anticoagulants. Males are also at an increased risk of hematoma development because of the increased dermal blood flow associated with hair follicles. Over resection of fat in the submental area can result in a so-called "cobra neck" deformity, and excessive tension at closure can pull the ear lobe inferiorly into a "pixie ear" deformity, both of which can be avoided with a more conservative surgical technique.

Permanent or temporary nerve injury can occur as well, particularly to the great auricular nerve, but also to the marginal mandibular branch of the facial nerve. Great auricular nerve injury leaves the inferior aspect of the pinna hyperesthetic, and marginal mandibular branch injury causes an asymmetric smile, because the lower lip depressors become weak. The uninjured side of the upper lip will depress normally, leaving the affected side higher up and causing an overall crooked appearance. Other standard risks apply as well, such as may occur with any other surgery: pain, bleeding, infection, scarring, alopecia, and need for further surgery.

The best way to avoid these complications is to be familiar with the relevant anatomy, operate meticulously, and counsel the patient thoroughly before surgery to ensure reasonable expectations. Additionally, the surgeon should have a low threshold for returning to the operating room within a year to perform a "tuck up" procedure to help remove any additional redundant skin that persisted or returned after surgery, or to address any remaining or platysmal bands, which also frequently recur after neck lifting.[12][13][14]

Non-surgical modalities can result in complications as well, including commonly the complaint that results fell short of expectations. Laser resurfacing may cause burns or scars if the settings are too aggressive; patients should be counseled to stay out of the sun for several months after laser treatments to help prevent any pigmentary abnormalities, either hyperpigmentation or hypopigmentation, that may occur during healing. Hyperpigmentation is most often temporary and is more common than hypopigmentation. Hypopigmentation is less common, but more likely to be persistent and is more difficult to treat.[15]

Injections may produce local reactions, and deoxycholic acid is known for causing significant edema as the adipocytes lyse. Botulinum toxin injection is generally very well tolerated, although if injected too superiorly, it may weaken the lower lip depressors and cause an asymmetric smile. Lastly, in rare cases, cryotherapy may cause paradoxical lipohypertrophy, which will require liposuction to treat.

Clinical Significance

In cosmetic surgery practices, aging of the neck is a very common complaint due to the frequency with which skin and muscle laxity develops over time. Accumulation of submental fat, in both the subdermal and subplatysmal compartments, further compounds the issue in most cases. Because there are so many options for addressing the aging neck, operative and non-operative, there is a role for a great number of clinicians of different specialties and levels of training in the management of patients with this chief complaint. Aestheticians, nurses, physician assistants, and nurse practitioners can all provide non-surgical treatment, and some may also assist in the operating room, or provide care that supports or supplements surgery. From 2019 to 2020, necklifts accounted for between 160,000 and 180,000 surgeries in the United States alone. Bearing in mind that the necklift often constitutes a key component of facelifting, that number could possibly be closer to 400,000 cases per year, making it a hugely popular surgical option. For this reason, it important for clincians outside of cosmetic practices to at the very least be aware of what options may be available to their patients, and more importantly, how to recognize complications from these treatments.

Enhancing Healthcare Team Outcomes

Because of the wide variety of modalities available for neck rejuvenation, an interprofessional team is an optimal method of providing comprehensive care to the cosmetic patient, ensuring that all pertinent options are presented and discussed appropriately. Experts in all relevant fields should participate in inpatient counseling to determine goals and set reasonable, attainable expectations. Surgeons, dermatologists, nurses, and anesthesia providers all have major roles to play before, during, and after rejuvenation of the aging neck.[16]