Introduction

Evaluation of female beauty and esthetics varies across cultures, but tends to focus on the breast and buttocks as key elements of investigation, evaluation and surgical intervention. Plastic surgical trends have largely focused on the breast; however, over the past 10 years augmentation and rejuvenation of the gluteal region have far outpaced intervention upon the breast and abdominal region. According to the American Society of Plastic Surgery trends, from 2000 to 2010, procedures which aim to enhance the esthetic of the gluteal region, including lower body lifting and specifically buttock lifting, have seen increases of 4550% and 143% respectively.¹

These procedures come in many forms, with intricacies and variations too numerous to expound upon in any text. There are currently three main avenues for rejuvenation and augmentation of the gluteal region: alloplastic implantation, autologous fat injection, and autologous tissue transposition/flaps. All of these techniques (and combinations thereof) are powerful tools in surgically improving the gluteal esthetic. Key to achieving the full potential of these techniques is a thorough understanding of the regional anatomy, as well as variations therein which predispose patients to one technique versus another. One must also consider these techniques to be utilized for personalized definitions of the gluteal esthetic, as various ethnicities define this differently. Furthermore, an understanding of anatomic changes in certain patient populations, such as the massive weight loss patient, is critical in designing the appropriate procedure for gluteal rejuvenation.

In this chapter, the authors set out to assist the reader in defining the relevant gluteal anatomy, in addition to targeted regions found to be of critical importance in defining the gluteal esthetic. With this background, the various techniques will be described in detail to address specific sites of deficiency, excess or derangement. Critical maneuvers, both inside and outside the operating room, will be expounded upon to help optimize results. Procedure-specific postoperative care will be discussed along with common complications and their successful management. It is the aim of this chapter to allow the reader to successfully evaluate, treat and manage the patient presenting for gluteal rejuvenation while minimizing complications and maximizing patient satisfaction.

Preoperative Preparation

The characteristics of the ideal gluteal esthetic must first be defined prior to the determination of an appropriate surgical plan for the patient presenting for gluteal contouring surgery. The gluteal esthetic was largely codified in 2006 by Cuenca-Guerra and colleagues.² Their analysis of over 2400 images of the gluteal area revealed four of the most recognizable characteristics of an esthetically pleasing gluteal region: (1) Two mild lateral depressions that correspond to the femoral greater trochanter; (2) A short infragluteal fold lying in the horizontal crease under the ischial tuberosity which does not extend beyond the medial two-thirds of the posterior thigh; (3) Two supragluteal fossettes (or dimples) on either side of the medial sacral crest which correspond to the posterior superior iliac spines (PSIS); and (4) A V-shaped crease (sacral triangle) which arises from the proximal end of the gluteal crease and extends toward the sacral fossettes (Fig. 39.1).

FIG. 39.1 Characteristics of esthetically pleasing buttocks: a mild lateral depression at the femoral greater trochanter, a short infragluteal fold, the supragluteal fossette corresponding to the posterior superior iliac spine and a V-shaped sacral triangle.

(Cuenca–Guerra, R and Lugo–Beltran I. Beautiful buttocks: characteristics and surgical techniques. Clini Plast Surg 2006;33:321–332.)

It is critical for one to understand the variations across ethnicities in defining gluteal esthetics. Roberts has outlined very specific variations of this basic framework between ethnic groups in the United States.³ The short infragluteal fold, supragluteal fossettes and sacral triangle are generally universally accepted, whereas mild lateral depressions tend not to be preferred by Hispanic or African-Americans. This population tends to prefer a fuller lateral gluteal region along with increased projection compared to Asian-Americans, who prefer a short buttock with a high point of maximum projection. United States Caucasians tend to prefer a more athletic ideal with greater muscular and bony anatomy definition with less anterior-posterior projection.

With these regions of a pleasing buttock region defined, one must have a systematic way to define the anatomy of the patient presenting for gluteal contouring. Centeno has described eight esthetic units that must be evaluated in order to design an appropriate, individualized surgical plan.⁴ From the posterior-anterior view, the gluteal region consists of two symmetrical flank units, a sacral triangle, two symmetrical gluteal units, two symmetrical thigh units, and one infragluteal diamond unit (Fig. 39.2). These regions should be individually considered and addressed in the surgical planning process. The junctions between these units serve as useful sites for incision placement during excisional procedures. Mendieta has subsequently divided these esthetic units into more discrete subunits.⁵ One must also consider the surrounding regions of the abdomen, anterior thigh, medial thigh, and lateral thigh. Derangement, overcorrection, or undercorrection of these areas may create overall disharmony as the gluteal region is surgically approached.

FIG. 39.2 Eight esthetic units described by Centeno utilized for individualized surgical planning: two symmetrical flank units, a sacral triangle, two symmetrical gluteal units, two symmetrical thigh units, and one infragluteal diamond unit.

Proper evaluation of the gluteal region is critical when planning surgical intervention. Mendieta has devised a classification system analyzing the underlying bony framework, gluteus maximus muscle, subcutaneous fat topography and overlying skin to assist in operative planning.⁵ It is the interplay of these variables that assists in selecting the appropriate procedure on an individual basis.

Mendieta begins with classification of the “frame”, which he defines as the bone, skin, and fat of the buttock region. Frame types are defined based on the location of three topographical landmarks: the “A” point representing the most protruding point in the upper lateral hip, the “B” point representing the most protruding point in the lateral thigh, and the “C” point representing the depression at the lateral mid-buttock (Fig. 39.3). The square buttock, most commonly seen, is defined as equal protrusion of points A and B. The round shape is similar, but is characterized as having excess fat deposition at point C. A-shaped frames are characterized as having more fat in the lateral upper thigh (B point); this is contrasted with the V-shaped frame which is characterized as having more fat in the upper lateral hip region (A point). These A-shaped and V-shaped frames have colloquially been referred to as “pear shaped” and “apple shaped”, respectively. Targeted liposculpture tends to be very effective in reshaping these frames to achieve a more esthetically pleasing gluteal region.

FIG. 39.3 Mendieta’s frame evaluation utilizing three critical landmarks.

(Mendieta C. Classification system for gluteal evaluation. Clin Plastic Surg 2006;33:333–346.)

The gluteus maximus muscle can then be evaluated. Mendieta classifies the gluteal musculature based on its height-to-width ratio with 1 : 1 being defined as a short muscle, 2 : 1 being defined as a tall muscle, and those in between defined as an intermediate muscle (Fig. 39.4). This classification scheme is particularly critical when one is evaluating a patient for gluteal implant placement. Patients with short gluteus maximus muscles are best augmented with round implants, whereas those with tall muscles require an anatomic implant. For those with intermediate gluteal muscles, evaluation of projection and shape from a lateral view assists in determining the appropriateness of a round, anatomic or oval implant shape.

FIG. 39.4 Mendieta’s muscle evaluation utilizing muscle height and width to assist in selecting appropriate gluteal implants.

(Mendieta C. Classification system for gluteal evaluation. Clin Plastic Surg 2006;33:333–346.)

A gluteal ptosis classification scheme has also been devised by Mendieta, which is similar in design to that of breast ptosis described by Regnault.⁶ Those patients with some buttock volume and skin falling slightly below the infragluteal fold are described as having Grade I ptosis. Patients with an apparent and angular infragluteal fold with skin drooping below it are classified as having Grade II ptosis. Those patients with severe skin laxity, along with a laterally extending infragluteal fold with an angle of greater than 30° are classified as having Grade III ptosis (Fig. 39.5).

FIG. 39.5 Mendieta’s ptosis evaluation utilizing skin fold angles for classification.

It is critical to appropriately and systematically analyze the complex regional anatomy of the buttocks prior to moving forward with surgical intervention. The interplay between the framework, musculature, fat deposition and skin envelope may be analyzed as above to assist in designing the appropriate surgical plan for the patient presenting for gluteal contouring.

Special consideration must be given to the massive weight loss population, who generally present with severe soft tissue deflation and excess skin. While circumferential body lifting assists in eliminating skin and soft tissue excess, it tends to flatten the gluteal region. Contouring and autologous augmentation of the buttocks in these patients is best achieved using de-epithelialized gluteal flaps.

Surgical Technique

Implantation of prosthetic devices, liposculpture with a combination of targeted suction-assisted lipectomy with lipoinjection, and rejuvenation utilizing autologous tissue flaps form the basis of surgical intervention. Combinations of these techniques have been described to fine-tune restoration of the gluteal esthetic. Below, the authors detail the appropriate techniques for utilizing these treatment modalities.

Prosthetic Gluteal Augmentation – Submuscular Approach

In 1984, Robles and colleagues described gluteal augmentation utilizing the submuscular space.¹⁰ This approach successfully addressed the capsular contracture and palpability complications seen with the subcutaneous approach. However, the anatomy of the submuscular space limits the augmentation that may be achieved. Because the sciatic nerve exits on the underside of the piriformis muscle at its inferior border, augmentation is limited to utilization of smaller round implants placed in a more superior location. This results in greater projection in the upper gluteal region with a deficiency in the lower portion (Fig. 39.6). Furthermore, with such superior placement, gluteal ptosis may not be appropriately addressed. Risk of direct injury to the sciatic nerve also accompanies this approach. While this technique may be used today for patients with a well-developed inferior gluteal region requiring upper pole augmentation, it has largely fallen out of favor with the advent of intramuscular and subfascial descriptions.

FIG. 39.6 Submuscular placement of gluteal prosthetics. Because of anatomic limitations, augmentation is limited to the utilization of smaller, round implants placed in a superior position.

IC, iliac crest; PSIS, posterior superior iliac spine; IGF, Inferior gluteal fold.

Prosthetic Gluteal Augmentation – Intramuscular Approach

The intramuscular approach to prosthetic gluteal augmentation provides padding both above and below the gluteal implant. Utilization of this space allows for better inferior placement when compared to the submuscular approach and decreases the risk of injury to the sciatic nerve (Fig. 39.7).

FIG. 39.7 Intragluteal placement of gluteal prosthetics. Dissection is superficial to the sciatic nerve, thus allowing for more inferior placement of the prosthetic. A 5–6 cm incision is made in the midline approximately 2.5cm superior to the anus. The depth of dissection, allowing for 2–3 cm of muscle thickness overlying the implant, is established. A closed suction drain is inserted through a separate stab incision. The implant is then inserted into the pocket and rotated into position. Closure is undertaken without undue tension.

The authors prefer the technique outlined by Mendieta.¹¹ Preoperative Decadron and clindamycin are administered and intermittent pneumatic compression stockings are applied. General anesthesia or epidural placement with IV sedation may be utilized. The patient is placed in the prone jackknife position with the entire gluteal region prepped and draped. A Betadine-soaked gauze is placed over the anus to prevent contamination of the surgical field. While a single midline approach had previously been advocated, two parasacral incisions are now utilized to minimize postoperative wound dehiscence. The midline is marked and two paramedian lines are drawn 1 cm lateral to the midline which curves to follow the upper gluteal curvature superiorly for a total length of 8 cm.

The incision lines, intramuscular and subcutaneous tissues are infiltrated with 1% lidocaine with epinephrine (adrenaline) 1 : 100 000. Incisions are made in the skin and taken down to the gluteal fascia. It is critical to preserve the gluteal fascia at this point to allow for closure and appropriate implant coverage. Approximately 6 cm of subcutaneous dissection is performed and the fascia opened for a length of 6 cm. Blunt dissection is taken perpendicular to the gluteus muscle fibers to a depth of 2–3 cm along the corresponding fascial incision. Pocket dissection with a tissue thickness coverage of 2–3 cm is created, beginning in a superolateral direction. At this point, given the lack of natural tissue plane and areolar tissue, the dissection will no longer be bloodless. Dissection continues in a sweeping counterclockwise motion from this superolateral point with little dissection (3–5 cm below the coccyx) undertaken inferiorly. A breast implant expander may be placed into the pocket at this time and over-inflated to assist in dissection. This is then replaced with a gluteal prosthesis sizer to estimate the volume of permanent implant to be used. A closed-suction drain is placed in the pocket and brought out through a separate stab incision in the infragluteal fold.

The implant pocket is then irrigated and the implant rolled and placed within the pocket. The muscle and subcutaneous layers are closed with absorbable braided suture in a layered fashion. It is critical that this closure be without undue tension to avoid dehiscence and implant exposure. The final skin closure is performed after augmentation of the contralateral buttock to ensure symmetry.