Isolated Neck Rejuvenation and Submentoplasty

A full lower face and neck lift is the gold standard procedure for rejuvenating the neck and jowls. As the demand for cosmetic surgical procedures has increased, surgeons are seeing a number of younger patients requesting improvement in their neck contour and that do not have advanced signs of facial aging, including jowling and descent of the malar fat pad. In addition, these patients are often seeking minimally invasive procedures and do not desire the extensive incisions associated with a traditional facelift. In the properly selected patient, either isolated liposuction of the neck or a submentoplasty can provide an excellent surgical result.

PATIENT ASSESSMENT

The ideal patient is in their 30s or 40s and has good skin and muscle tone but an obtuse chin-neck angle. It is important to assess the position of the hyoid bone, since a low and anterior positioned hyoid will result in an obtuse cervicomental angle despite good surgical technique.

Many patients with obtuse cervicomental angles have excess fat in both the pre- and postplatysmal planes. It can be difficult to assess the fat distribution above and below the platysma, but an estimate can be done by gently pinching the skin with your fingers as the patient grimaces to tighten the platysma muscle. If there is any doubt, a submentoplasty is preferred so that direct excision of subplatysmal fat can be treated by direct excision. Attempting to liposuction subplatysmal fat is unsafe for obvious reasons of neurovascular injury.

If the patient’s hyoid bone is positioned low and anterior, the surgeon should discuss the limitations of neck liposuction or submentoplasty; and also consider adjunctive procedures, such as a chin implant to camouflage the obtuse contour.

Prior to recommending liposuction or submentoplasty, it is also important to recognize any submandibular gland ptosis. Typically, this is seen as a small chestnut-size mass in the neck several centimeters below the angle of the mandible. If submandibular gland ptosis is unrecognized, then the esthetic result will be less than satisfactory, since the prominence may be even more visible once overlying fat has been removed.

Although attempts have been made at resuspending the submandibular gland, this is often difficult and has limited success. Also, submandibular gland resuspension cannot be preformed via an isolated submental incision. Currently, I manage this problem with partial resection of the superficial portion of the submandibular gland through a submental crease incision

LIPOSUCTION

The ideal candidate for liposuction is usually a patient less than 40 years old who has good skin tone with a favorable hyoid position and localized submental and submandibular fat deposits. If there is minor platysmal banding, consideration for botulinum toxin type A injections to the platysma with liposuction can be considered. However, significant platysmal banding or laxity will need to be treated with submentoplasty.

The technique for cervicofacial liposuction has evolved over the years, and the use of micro cannulas in this area has become the preferred technique to prevent over-resection and a skeletonized appearance of the neck.

Some surgeons believe that using ultrasonic or laser-assisted liposuction of the submental region will provide additional benefit by providing tightening of the dermis related to the heat generated from these techniques. There is no good scientific evidence to suggest that these techniques are any better than traditional liposuction. In properly selected patients, it is expected that the skin will contract to take on the new contour sculpted with the cannulas. If the skin tone is borderline prior to the procedure, patients should be warned that they may require additional surgical procedures (such as a facelift).

TUMESCENT SOLUTION

Tumescent anesthesia originated in the dermatology literature where safe liposuction could be performed under local anesthesia alone. It was found that using a dilute solution of lidocaine and epinephrine decreased the blood loss during liposuction and provided safety to the technique. The word “tumescent” is of Latin origin and means “to swell.” The increased volume provided by the solution creates a firmness to the tissues that allows the surgeon to more accurately sculpt the tissues.

The maximum safe dose of lidocaine is 7 mg/kg, as published in the Physicians’ Desk Reference. This dose limit was established in 1948 by a letter to the FDA from Astra Pharmaceuticals that stated the safe dose of lidocaine was “probably the same as that for procainamide.” Jeffrey A. Klein, MD, challenged this dogma and developed the tumescent anesthesia technique for liposuction in 1986. Since then, many variations in the concentrations of lidocaine and epinephrine have been used and total insufflated volume has been decreased if the patient is receiving a general anesthetic, and has been referred to as a superwet technique.

Through well-documented prospective studies, an estimated safe upper dose of lidocaine in highly diluted form used for body liposuction has been validated at 35 mg/kg. This is five times the previously published limit. For body liposuction, the current estimate for the safe maximum dose of lidocaine is 50 mg/kg, and doses greater than 55 mg/kg should be avoided.

In 20 patients, doses of lidocaine in the range of 50 mg/kg were administered and peak serum blood levels were noted to be less than 3.5 ug/mL. The toxic serum threshold is reported to be 5 ug/mL. It is important to note that peak lidocaine levels do not occur until 12 hours after administration during tumescent technique for body liposuction.

Much lower amounts of solution are injected in the face. The dose of lidocaine should never approach the levels used in body liposuction. Not surprisingly, the rate of absorption in the face is much faster due to the excellent blood supply. Serial plasma lidocaine levels have been measured when using tumescent anesthesia on the face. In one study, the peak plasma levels averaged 2.7 ug/mL. The highest level found in the series was 3.3 ug/mL. Also, the serum levels normally peaked at 1 hour after administration rather than 12 hours body tumescence. Thus, any signs of lidocaine toxicity in facial procedures should be evident prior to discharge.

Epinephrine is essential to the mixture of tumescent anesthesia. It provides the profound vasoconstriction mediated by alpha-1 agonist effects, which limits blood loss during liposuction. Additionally, it decreases the rate of absorption of lidocaine, thereby decreasing systemic toxicity. The most common adverse reaction to epinephrine is a tachyarrhythmia related to the beta-1 agonist effects. Use of clonidine as a premedicant has been shown to reduce the incidence of intraoperative and postoperative tachycardia with tumescent local.

Bicarbonate is usually added to the tumescent mixture to reduce the stinging pain due to the acidity of lidocaine injected in an awake patient. It is usually added to obtain a concentration of 10 mEq/L. If the surgery is to be done under general anesthesia, the bicarbonate is eliminated from the mixture.

TECHNIQUE

The patient is marked in an upright position prior to induction of general anesthesia. After a sterile prep, the neck is injected with enough tumescent solution to facilitate contouring. On average, this is about 150 mL of a mixture containing 30 cc of 2% lidocaine (600 mg) with 1.5 cc of 1:1000 epi (1.5 mg) in 500 cc of normal saline. This then makes a mixture of 0.12% lidocaine with 1:333,333 epinephrine.

The mixture is injected with a Wells Johnson Klein (Tucson, Ariz) pump and a 22-gauge spinal needle into the submental region staying superficial to the platysma.

If neck liposuction is to be performed, stab incisions are made with a #11 scalpel blade in the submental region, as well as just behind the pinna of the ear bilaterally.

A small, 1.5- or 2-mm micro liposuction cannula is used to perform the liposuction. Small cannulas decrease the likelihood of having uneven or lumpy results. The cannula opening should always be pointed toward the platysma to prevent gouging of the dermal tissues, which can result in increased scarring, induration, and palpable skin irregularities.

After liposuction is completed, a single 5-0 plain gut suture is used to close the stab incisions. Self-adhering Reston Foam™ 1563L (3M Medical-Surgical, St Paul, Minn) is placed over the submental region, and Coban™ (3M Medical-Surgical, St Paul, Minn) head wrap is gently applied. This is kept on for 24 hours. When the patient returns the next day, the wrap is removed and a facelift bra is placed. This is to be worn as much as possible, day and night, during the first week. After 1 week, the patient is to wear the garment at night only for 2 more weeks.

Complications reported with facial liposuction include dermal injury with postoperative indurations, skin irregularities, prolonged swelling, seromas, hematomas, sialoceles, transient and permanent injury of the marginal mandibular nerve, and postinflammatory hyperpigmentation.

SUBMENTOPLASTY

When the patient has good skin tone with subplatysmal fat or platysmal banding without jowling, an isolated submentoplasty is a desirable procedure. There have been many techniques described to manage the neck through a submental crease incision. The technique to be described is my preferred method to address the neck when a facelift is not to be performed.

Tumescent anesthesia is used to insufflate the preplatysmal plane as described earlier with neck liposuction. A 2- to 3-cm incision is made just posterior to the natural submental crease. This is especially important if a chin implant is to be used, since the recruited skin from the neck will move the incision anteriorly and possibly become visible.

Dissection is carried down to the level of the platysma with a needle-tip point cautery. The skin is widely undermined inferiorly to the thyroid cartilage and laterally to the posterior border of the mandible, leaving all the preplatysmal fat attached to the dermis. No liposuction is performed prior to this procedure, since an even thickness of superficial fat attached to the dermis when the skin is redraped will decrease the likelihood of irregularities. It is important to widely undermine the skin so that it lays down smoothly after addressing the platysma and subplatysmal fat.

Once the platysma is completely exposed, the surgeon must decide how to address the platysma and subplatysmal fat. In patients with a well-developed platysma, I prefer to back-cut the platysma at the level of the hyoid bone, raise platysma flaps, and remove unwanted subplatysmal fat with electrocautery. If the submandibular gland is prominent and may interfere with obtaining a good result, then the superficial portion of the gland is resected with cautery respectful of the facial vessels and nerve.

A single 2-0 vicryl suture can be placed in the superficial cervical fascia to cover the remaining gland and decrease the likelihood of sialocele. The platysma flaps are then mobilized and plicated in the midline and secured to the periosteum of the hyoid bone using a 2-0 vicryl suture in a running vertical mattress technique. The vertical mattress helps invert the free edges of the platysma and helps keep a smooth contour.

In patients with a very heavy neck with significant fat deposits both above and below the platysma or a poorly developed platysma, resection of the platysma is performed rather than plication. This technique should be done with caution. Irregular resection or inadequate fat left attached to the dermis can result in a very irregular submental contour that is undesirable.

Prior to closure, the skin is redraped and the contours are assessed. If the fat attached to the dermis is too thick, a large spatulated liposuction cannula can be used to carefully thin it. If needed, a chin implant is placed and secured to the mandible with self-drilling titanium screws. The skin is closed and a dressing is placed using Reston Foam 1563L and a Coban head wrap. This is worn for 24 hours. When the patient returns the next day postop, the wrap is removed and the patient then wears a compression garment (such as a facelift bra). This is to be worn as much as possible, day and night, during the first week. After 1 week, the patient is to wear the garment at night only for 2 more weeks.

ADDITIONAL PROCEDURE

Poor neck contour is a frequent complaint of patients. Often, the most appropriate procedure is a cervicofacial rhytidectomy. However, there are instances when a less aggressive and perhaps minimally invasive procedure can provide good aesthetic results. Both neck liposuction and isolated submentoplasty are well suited to patients with good skin that do not desire a full facelift. Naturally, patients must be informed that they may require additional procedures if these isolated techniques are not completely effective to treat their problem.

Limitations aside, isolated neck liposuction with or without associated submentoplasty can be a superb minimally invasive cosmetic procedure. The appropriate patient will appreciate the improved neck appearance coupled with a decreased downtime as compared to traditional neck or facelift techniques.

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James Koehler, MD, DDS, is in private practice with Tulsa Surgical Arts, Tulsa, Okla, and is associate clinical professor, Department of Surgery, at Oklahoma State Medical School in Tulsa. He can be reached at (918) 392-9988 or .