Belt lipectomy

Anatomy

It is important to have a clear understanding of the blood supply of the abdomen, when contemplating circumferential dermatolipectomy of the lower trunk. The anatomy of abdominal wall blood supply is reviewed elsewhere.

The subcutaneous abdominal fat is divided into superficial and deep layers by the superficial fascial system, which in this region of the body is called Scarpa's fascia. In thin patients, the two layers are fairly close to each other in thickness. In patients who have a high BMI, the superficial layer is often much thicker than the deep layer.

There are areas within the trunk where the skin/fat envelope is tethered to the underlying musculoskeletal anatomy, restricting either descent or elevation, which can occur with aging, weight fluctuation, or surgical manipulation. These areas are called “zones of adherence” and act like “hooks” for the skin/fat envelope to hang on to as it descends, especially after the skin has been stretched by excess weight and then deflated by weight loss ( Fig. 31.1 ). The zones of adherence overlying the spine and the sternum are both strong areas of adherence and are always present, while the zone of adherence overlying the midline linea alba of the abdomen is often weak to non-existent. There are strong zones of adherence overlying the inguinal region bilaterally that play an important role in controlling final scar position during bodylift/belt lipectomy. A more variable zone of adherence is located in the horizontal suprapubic area, which when present leads to a suprapubic crease. This zone of adherence, along with the inguinal zones of adherence, are responsible for a panniculus hanging over the mons pubis.

Another important zone of adherence is located between the hip and lateral thigh fat deposits and can prevent mobilization of tissues during surgery. In some procedures, such a “lower bodylift type II”, as described by Lockwood, this zone of adherence is intentionally disrupted to allow for significant elevation of the lateral thighs.

There are three groups of patients that can potentially benefit from bodylift/belt lipectomy. Although all of these groups will share some of the same indications and principles in design of the operations, they differ and should be considered here.

BMI level at presentation

Massive weight loss patients will present to the plastic surgeons at different BMI levels (or different levels of deflation). For some, this level is still very high, BMIs of ≥35; for others, it may be intermediate, BMIs of 30–35; and for others, the BMI may drop to the mid- or low 20 s (see Fig. 31.6 ).

Fat deposition pattern

The type of deformity that an MWL patient presents with also depends on their particular fat deposition pattern. Humans are born with a genetically controlled pattern of fat deposition, as well as a fat loss pattern. For example, females generally tend to store fat in the extraperitoneal space, the lower abdomen, hips, and thighs – a pattern often referred to as “pear-shaped” ( Fig. 31.7 ). Males, on the other hand, tend to store fat more centrally, in what is often referred to as an “apple-shaped” configuration, where fat is deposited intraperitoneally and in the flanks (or “love handles”), and less fat is deposited in the thighs (see Fig. 31.7 ).

The skin/fat envelope

The skin/fat envelope is what a plastic surgeon operates on, and its intrinsic properties are especially important. Some patients present with very pliable and thin skin/fat envelopes, while others will present with very thick non-pliable tissues. A concept that the authors have found very helpful in examining these patients is the “translation of pull” ( Fig. 31.8 ). For example, when examining the patient prior to surgery, the lateral abdominal tissues are pinched, simulating the effects of the lateral abdominal resection of a bodylift/belt lipectomy on the distal thigh, which can be predictive of the final result with a certain degree of accuracy. If the pinch demonstrates very little translation of pull to these areas, as in the case of patients who present with high BMIs and thick, non-pliable skin/fat envelopes, this can be used to predict the final result. As a general rule, the greater the BMI drop, the more translation of pull will be present.

Commonalities of presentation

Almost all MWL patients present with a “hanging panniculus”. The size and shape of the panniculus will vary from one patient to the other based on their intrinsic fat deposition pattern ( Fig. 31.9 ). Almost every MWL patient will present with a “ptotic mons pubis”. The most obvious deformity is vertical excess with varying degrees of horizontal excess.

The waist, which is the narrowest aspect of the lower trunk between the ribs and the pelvic rim, can be blunted in many MWL patients by the hanging skin/soft tissue envelope as it drapes from the ribs to below the pelvic rim. The anterior and lateral thighs are usually ptotic. In patients who belong to the “20–30 pounds overweight” group and “the normal weight” group, the thighs are not as dramatically affected but are usually central to the need for a circumferential approach.

As with the thighs, the buttocks in the MWL patient are usually ptotic due to the effects of the weight gain/loss process. Many MWL patients also present with a lack of demarcation between the lower back and buttocks ( Fig. 31.10 ).

Many patients present with back rolls that are bothersome. Some back rolls are located in the lower back and those are generally amenable to improvement through bodylift/belt lipectomy. Superior back rolls, usually contiguous with breast rolls, or just below them, are not affected by bodylift/belt lipectomy procedures and must be addressed through upper bodylift procedures ( Fig. 31.11 ).

Patient selection

Although a “bodylift/belt lipectomy” can be thought of as a circumferential wedge excision of the lower trunk, there are variations of the procedure. We have categorized what we feel to be the ends of the spectrum of bodylifts and will go over the differences so that the reader may understand what each can accomplish. At one end is the “lower bodylift type II”, as originally described by Lockwood. At the other end, there is the “belt lipectomy”, as described by the authors, originally in Iowa. It is not the intent of the authors to suggest that one type of bodylift should be utilized over the other. Rather, it is hoped that the surgeon would be familiar with these techniques and be able to individualize the particular procedure to the needs of their particular patient.

Lower bodylift type II (Lockwood technique)

In this type of bodylift, the overall circumferential wedge of resection is located lower onto the lower trunk. The procedure can be thought of as a truncal–thigh lift, not just a truncal lift. This technique is discussed in more detail in Chapter 32 . The bilateral zones of adherence located between the hip and trochanteric fat deposits are intentionally destroyed by discontinuous undermining and/or aggressive liposuction to allow the surgeon to lift the lateral and anterior thighs very aggressively.

The result of a lower bodylift type II is impressive in its elevation of the thighs, and it creates a fairly low scar that can be covered by most underwear or swimwear patterns ( Fig. 31.12 ). There are disadvantages and limitations of lower bodylift type II. Since the final scar is intentionally created below the widest aspect of the pelvic rim, the waist is not narrowed as much as it would if the final scar is created above. The authors call this the “sundress effect” because it pulls down the upper truncal tissues across the narrowest aspect, the waist, onto the widest aspect, the pelvic rim, leading to blunting of the waist, rather than narrowing. Anteriorly, the scar is considerably lower than the anterior superior iliac spine (ASIS), which poses no significant problem if the abdominal flap that is brought down to the level of the scar is thin. However, if the abdominal flap is thick, as in higher BMI patients, it will add to the prominence of the ASIS region, which should be flat, not convex. A disadvantage of a posterior low scar in a lower bodylift type II is that it violates the aesthetic unit principle. This is not problematic in patients who value hiding the scar within low underwear lines and do not require demarcation between the lower back and buttocks, i.e., a male patient. On the other hand, most female patients desire as much buttocks definition as possible and demarcation between the lower back and buttocks. Box 31.1 shows the main advantages and disadvantages of the lower bodylift type II.