What is an abdominoplasty?
An abdominoplasty is a surgical procedure that recontours the abdomen. This is achieved by addressing several issues:
• Removing excess skin and subcutaneous fat of the abdomen
• Tightening lax abdominal musculature (usually a result of pregnancy)
• Rejuvenating the mons (the area of hair bearing skin above the genitals
• Narrowing the waistline
• Smoothing the lateral contour of the trunk
• Recontouring the flanks and back (in extended and circumferential procedures only)
Abdominoplasty is in contradistinction from liposuction, which is a procedure to remove excess subcutaneous (below the skin) fat, however, excess skin is not removed. Over the past 22 years, from the time I was a resident in plastic surgery to the present, I have seen many changes in both liposuction and abdominoplasty. The two procedures became more and more refined, yielding better and better results, with less discomfort and downtime, as well as a greater margin of safety. What I find most interesting, is that each of these procedures developed and matured, independent of the other. Also on note is the fact that in the past, a patient would undergo either abdominoplasty or liposuction, but not both at the same time, to recontour the trunk. Now, it is more common to utilize both techniques to create a more comprehensive restorative plan to rejuvenate the trunk.
Removing excess skin and subcutaneous fat of the abdomen
The best patient for liposuction has minimal excess skin but has excess subcutaneous fat and the best patient for an abdominoplasty has the opposite situation: minimal excess fat but does have a significant excess of abdominal skin. This doesn’t mean that a patient is not a candidate for an abdominoplasty if the also have excess subcutaneous fat, or a patient is not a candidate for liposuction if they have some excess skin, I am just speaking in the most ideal of circumstances. Many patients who obtain wonderful results from both surgeries do not fall at the far ends of the spectrum.
Figure 1: The spectrum of balance between excess skin and fat
The patient represented by the left figure would probably be best contoured with liposuction, as her problem is mostly excess fat with little excess skin. If an abdominoplasty is performed, little excess skin will be removed and the overall appearance will not be significantly changed. The patient on the right, however, would probably be best serrved undergoing an excisional procedure such as an abdominoplasty. Liposuction alone will not deal with all the excess skin. The patient in the middle has more excess skin than the patient on the left, but not as much as the patient on the right. It is a judgment call in these cases, and sometimes, neither abdominoplasty nor liposuction will be clearly indicated over the other. In these cases, the surgeon must determine what bothers the patient the most, how the patient feels about the resultant scars and give the patient several options.
The incision for an abdominoplasty is typically placed in the waist crease, sometimes a little lower. The incision is made down to the abdominal muscles and then the skin is elevated upwards. In all types of abdominoplasties with the exception of the mini-abdominoplasty, the skin is elevated above the umbilicus (the navel) up towards the lower margin of the rib cage. When this is done, an incision must be made around the umbilicus so as to keep the umbilicus attached to the muscles as the skin is elevated upwards above it.
Figure 2: Variations in skin elevation. Two variations of abdominoplasty. In both examples, the incision in the waist crease and around the umbilicus are the same. The difference is that the example on the left includes wide “undermining” or elevation of the skin off the abdominal wall muscles. This mobilizes a great deal of abdominal skin, but at the cost of decreasing the blood supply and innervation (supply of sensation via sensory nerves) to the abdominal skin. In some cases, this may result in difficulties with wound healing, although in non-smokers, this is rarely the case. There is also a larger “dead space”, the space betwen the abdominal wall muscles and the undersurface of the overlying skin, and more fluid may accumulate there. The example on the right is one of “limited undermining” in which more of the circulation and innervation is preserved, with less dead space. The benefit is greater margin of safety with regard to maintaining blood supply to the skin to prevent wound healing problems, better preservation of sensation and a lower risk of accummulation of fluid betwen the skin and the underlying muscles during the postoperative period. The extent of lateral (sideways) undermining required depends upon the laxity and thickness of the overlying skin. I prefer to keep the lateral undermining to the absolute minimum that I can and still get proper re-draping of the skin over the abdominal wall musclulature for all the reasons discussed above.
Tightening lax abdominal musculature
A developing fetus is a powerful force acting upon the abdominal musculature, slowly causing the abdominal wall to stretch over the nine month gestational period. Changes in hormone balance during pregnancy also act to facilitate the ability of the body’s tissues to stretch, preparing the woman’s body for the future birth of her child. I don’t want my male patients to feel left out at this juncture, I am just addressing this portion of the discussion to the ladies because men do not experience pregnancy. When I am recontouring a male abdomen, the abdominal wall often does not require tightening.
Now here’s the myth – the muscles don’t really get tightened! We use the term “tightening the muscles”, I have certainly been guilty of using this term because in a lay sense, patients know what I am talking about – making their abdominal wall tighter. I usually then go into greater anatomical detail with my patients as I will here.
First: a brief anatomy lesson. The abdominal wall is made up of several muscles: the Rectus Abdominus, External Oblique and Internal Oblique muscles. The Rectus Abdominus muscles are a pair of vertical muscles that measure approximately four inches wide and run from the underside of the rib cage to the pelvis, traversing the entire abdomen. There are three “tendinous inscriptions” or pleats in the muscle that run horizontally. These pleats are what divide the muscle up into sections which have been termed “the six pack”. whether or not you can see those pleats depends on the thickness of the skin and fat overlying the muscle as well as how well the muscle itself is developed. The muscles lie side by side and are separated by approximately 1 – 2 cm. On the lateral (outer) sides of these muscles lie the Internal Oblique and External Oblique muscles whose fibers run, as their name states, obliquely (at an angle) from the side of the trunk to the Rectus Abdominus and from the ribs to the pelvis.
The abdominal muscles are enveloped, or wrapped by an investing fascia. Fascia is a thin, but strong sheet of tissue that covers the surfaces of muscles and other structures in the body. Although not very interesting to some anatomists, fascia is of paramount importance to surgeons because it is the fascia that is strong enough to hold sutures (stitches) placed during surgery. You may say “muscles are strong, why not place sutures in the muscles”? The fact is, although a contracting muscle generates a lot of force, the muscle tissue itself is not really good at holding sutures. The sutures will just pull right through the muscle tissue. Below is a diagram of how it all fits together. This diagram is what we call a “cross-sectional view.” Imagine cutting through the abdominal wall from right to left and then looking at the edge of the tissue, again from left to right. This diagram shows the relationship between the muscles and the fascia. The fascia covers the muscles from above and below, but it is the fascia above the muscle that is of greatest thickness and strength and is what surgeons rely upon to tighten the abdominal wall.
Figure 3: Abdominal wall cross section showing relationship of muscles and fascia.
The sutures are shown placed into the muscle fascia to provide tightening of the abdominal wall