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Bariatric surgery has become an effective treatment for severe obesity. Various techniques have evolved over the years, with the most common now being the Roux-en-Y gastric bypass. Patients who experience massive weight loss are left with disfiguring skin laxity that warrants surgical excision of the redundant tissue. Our experience comes from 400 abdominoplasties performed on patients with massive weight loss over the past 20 years. Special consideration must be given to this subset of patients when designing their abdominoplasties because of compromised vascularity from previous surgeries and persistent volumes of subcutaneous adipose tissue. In particular, the groin flap or cross-abdominal flap or both are presented as options for the postbypass patient in whom subcostal and midline scarring is present. The reverse abdominoplasty remains an option in special circumstances. In addition, we focus on complications these patients are more likely to develop, mainly related to associated incisional hernias and a disrupted vascular anatomy.
Obesity remains one of the leading health issues in today's society and could lead to a decrease in the life expectancy in the United States.1 The comorbid conditions associated with obesity are numerous and include coronary artery disease, type 2 diabetes, sleep apnea, osteoarthritis, and cancer.2 The risk of obesity-related disease is further increased by centrally distributed adiposity.3 Obesity has increased the lifetime risk of diabetes to 30% to 40% for an individual born in the United States,4 and studies have shown that obesity causes about 300,000 deaths per year in the United States.5 Defined as having a body mass index (BMI; weight in kg/height in m2)6 greater than 30, obesity has reached epidemic proportions mainly because of poor diets and sedentary lifestyles. The prevalence of obesity among adults has risen 50% per decade, and it is now estimated that at least 30% of Americans are obese.7 Morbid, or severe, obesity is now classified as a BMI of at least 40 or a BMI of at least 35 with comorbidities.8
For the obese individual who has exhausted a program of regimented diet and exercise, bariatric surgery has evolved into an effective solution. Massive weight loss not only leads to greater functional capacity but also improves the overall health of the patient.9 Two types of surgical procedures have been developed for the treatment of obesity: malabsorptive and restrictive. Restrictive procedures aimed at causing early satiety include stapled gastroplasty and gastric banding. Vertical banded gastroplasties, although once a popular option, yielded poor rates of weight loss maintenance in long-term studies.10 Reviews of patients who underwent gastric banding with either premeasured or inflatable bands demonstrated high rates of stenosis requiring reoperation and also unreliable weight loss results.11 The Roux-en-Y gastric bypass has become the most popular, effective, and well-tolerated bariatric procedure and is the procedure used in the great majority of patients in our series. The procedure combines the creation of a 30-mL gastric pouch with a gastrojejunostomy. Patients can expect a 65% to 75% loss of excess weight, and the incidence of dumping syndrome that results from the rapid transit of contents from the gastric pouch to the jejunum is low.12 The most common morbidities associated with the gastric bypass are iron and vitamin B12 deficiencies, seen in more than 30% of patients, with a consequent microcytic anemia, seen in half of patients who develop iron deficiency.13
The introduction of laparoscopy to bariatric surgery has increased technical choices for these procedures. Although they are increasingly popular, studies demonstrating superiority over open bypass procedures are pending. Certainly, the obvious advantage of decreased scarring, decreased chances for incisional hernia, and shorter recovery may be anticipated.
Our experience comes from 400 abdominoplasties selected from a series of over 2800 cases of massive weight loss as a result of either gastric bypass, gastric banding, or gastroplasty. Patients have shed an average of 100 pounds, leaving them with severe redundancy of their abdominal skin. This aesthetically displeasing consequence can impede the patient's psychological, as well as functional, improvement and therefore necessitates excision to achieve a flat abdomen.14 Persistent intertrigo, back pain, and limited exercise tolerance are frequently experienced by this group.
Traditional surgical correction of excess abdominal skin and fat involved a panniculectomy, as first reported in the United States by Kelly.15,16 Modifications occurred in the early 20th century including a variety of incision designs, extensive undermining,15 and umbilical transposition,16 but it was Pitanguy's report17 on his series of 300 abdominal lipectomies that provided ample justification for the modern abdominoplasty. Today, abdominoplasties are classified according to the type of incision used: transverse,18,19,20,21,22 vertical,23,24 or combined.25,26 In the experience of the authors, transverse incisions are most appropriate in the patient with massive weight loss. Combined excision of midline vertical scarring is commonplace.
In addition to extensive undermining at the level of the loose areolar tissue overlying the anterior rectus sheath, plication of the rectus muscle or the use of external oblique flaps to contour the abdominal girdle is a distinguishing feature of the modern abdominoplasty. These abdominal wall maneuvers are less important in the patient with a persistent thick pannus. Undermining should extend superiorly to the costal margin and xiphoid process. The superficial vascular supply of the abdominal skin consists of the superficial inferior epigastric, superficial pudendal, and superficial circumflex iliac arteries.27 Sacrifice of this vascular network on initial incision and dissection makes the abdominal flap dependent on the superior epigastric and intercostal perforators.28 Plication of the rectus abdominis muscle for patients with diastasis recti is performed using a two-layer imbrication of anterior rectus sheath. This provides a double layer of closure for those with incisional hernia. A simple interrupted layer using a 2-0 or 3-0 nonabsorbable suture should be followed by a running layer of absorbable suture. Alternatively, tightening of the waistline may be performed using two vertical fusiform plications at the lateral margins of the rectus.29 This technique, although insufficient by itself for cases of marked median diastasis, may serve as an effective adjunct in the massive weight loss patient but only when the advancing flaps are thin. Another method that has been described to contour the abdominal girdle involves the use of external oblique muscle flaps superimposed at the midline.30,31 Vertical laxity of the abdominal wall may be corrected using a horizontal plication on either side of the umbilicus in a manner very similar to vertical plication.32 Restoration of the median raphe, although difficult in the massive weight loss patient, may be attempted by midline resection of fat to the level of Camper's. This maneuver is rare in the weight loss patient as it further compromises blood supply and because of the frequent presence of a midline scar. By far, our most common procedure remains a two-layered rectus plication over subcutaneous redundancies from a low transverse incision with vertical scar excision (Fig. 1). The umbilicus is left in its midline position on an umbilical stalk and skin transposed around it. Two hemispherical excisions in advancing skin flaps make place for its transposition. Multiple basting sutures are used to secure the advancing subcutaneous tissue to the anterior abdominal wall fascia to close dead space and help prevent seroma formation.
There are several justifications for a true abdominoplasty in the patient with massive weight loss. Undermining to the level of the xiphoid process allows adequate access for repair of any associated incisional hernia. Large hernias, impossible to close primarily, may be repaired with a synthetic mesh or AlloDerm anchored to the fascia. Because of the compromised blood supply of skin overlying a hernia sac, excision is warranted and is best accomplished using an inverted T pattern. The consequent vertical scar, although perhaps longer than the original, is well tolerated. Removal of the abdominal pannus is perhaps the primary concern of a patient with severe skin laxity after massive weight loss. Raising and advancing the abdominal flap leave the patient with a far more appealing result compared with a simple panniculectomy. The line of incision should be marked preoperatively with the patient standing. Downward traction on the superior flap and upward traction on the inferior flap with the patient on a flat operating table are the best way to determine the maximum amount to be excised. Extra care must be taken to avoid overexcision and a consequent closure under excessive tension in this subset of patients because of their predisposition toward wound complications.33 The operating table should be flexed during closure to reduce tension.34 This true abdominoplasty allows access to the umbilical stalk, which many times must be shortened. Isolation of the stalk using a circular incision allows transposition, which is many times drastic in this population of patients. Preservation of the umbilicus should be routine except in the case of a hernia sac undermining the stalk. In these cases, umbilectomy may be necessary at the time of resection of this sac. A more natural appearing umbilicus can be reconstructed with use of the superiorly based, triangular skin flap during exteriorization.35 When the umbilicus is sacrificed, any of several reconstruction options are possible either primarily or secondarily.
Almost all patients who are morbidly obese and experience a massive weight loss are left with disfiguring abdominal laxity. The specific amount and distribution of this redundancy are related to the volume lost, the skin's adherence to the underlying fascia, and each patient's inherited pattern of fat deposition.36 In the nonobese patient with a thin pannus and laxity of the abdominal skin, a traditional abdominoplasty is the preferred treatment. These patients typically do quite well and their incidence of complications is relatively low.
The patient with a thick abdominal pannus despite undergoing massive weight loss presents a more challenging problem. Fat necrosis is much more common in this subset of patients, as is seroma formation. There are some steps the surgeon may take to minimize the risk of complications. The costomarginal branch of the deep superior epigastric artery is usually encountered during undermining and care should be taken to preserve this vessel to ensure adequate vascular supply to the superior flap. In addition, lateral undermining should be limited, ideally not extending past the anterior axillary line. Finally, limiting the amount of body contouring by excision or suction, or both, reduces the risk of flap necrosis and fat necrosis caused by disrupting the subdermal vascularity (Fig. 2).
Patients who have undergone previous abdominal surgery have an interruption in at least one of their anatomic vascular zones37 and therefore require special designs for their abdominoplasty. The exception to this is the patient who has been previously treated laparoscopically. This patient can undergo traditional abdominoplasty without significant increase in the incidence of flap necrosis.
The patient who has sustained subcostal incisions as for previous open cholecystectomy and then midline incision is in special jeopardy for flap loss (Fig. 3). When a lower transverse incision is planned, special considerations are required. These scars and subjacent skin should be excised to allow flap mobilization off fascia. The combined subcostal and vertical midline scar indicates probable previous sacrifice of the superior epigastric artery. The scars should be completely excised to release any tethering from fibrosed tissue and allow adequate flap advancement. In addition, if a midline incisional hernia is encountered, the vascularity to the overlying skin may be further compromised. The surgeon has options to replace this defect. The right groin flap relies on the inferior superficial epigastric artery for its blood supply. Its use leaves the patient with a zigzag scar in the middle of the lower abdomen (Fig. 4). Undermining should extend down to the inguinal ligament to allow maximum advancement. Although color match of the lower abdominal skin is not advantageous and there are inherent discrepancies in flap thickness, this groin flap allows reliable coverage for the subcostal defect on the right side. A second flap that can be used in this circumstance is a cross-abdominal “wrap-around” flap. This may be appropriate when a subcostal scar is found more tangential than horizontal, closer to midline (Fig. 5). As before, the previous scar is excised and the defect is filled with a rotational flap based on the left superior epigastric artery. The resultant scar configuration is a long midline vertical that extends inferior to the right groin. The umbilicus may be at the scar or to its left remaining at the midline in fascia. Breakdown at the distal paramedian border of the flap is possible, and patients should be apprised of potential breakdown at the corner of the closure. The best way to avoid superficial flap necrosis is adequate undermining of the cross-abdominal flap to minimize tension. In marking this resection, it becomes obvious that the length of the left-sided flap is longer than the standard to allow the extra tissue required for the wrap-around.
The presence of a chevron scar in the upper abdomen indicates previous sacrifice of bilateral superior epigastric arteries. The treatment of choice in these patients is the reverse abdominoplasty, with vascular supply coming inferiorly through bilateral superficial epigastric arteries (Fig. 6). The patient is left with a scar below the inframammary fold that meets at the level of the xiphoid process in the midline. Although the thickness of the advancing lower abdominal pannus is undesirable, the reliability of these flaps is significant. Secondary procedures to thin the pannus by suction lipectomy or further resection may be appropriate.
Many procedures may be combined with the abdominoplasty as part of the increasingly popular total body lift.38,39 These include brachioplasty, reduction mammoplasty, mastopexy, thighplasty (either medially40 or circumferentially), and belt lipectomy. We prefer a staged approach to these patients. In the first stage, an abdominoplasty is done in conjunction with either a modified lower body lift with medial thighplasty or with mastopexy/reduction. The second stage concentrates on correction of either breast ptosis and epigastric and midback redundancy or brachioplasty. The high-lateral tension abdominoplasty for patients with moderate to severe laxity of abdominal skin, fat, and muscle provides a modest amount of tightening of the buttocks, upper thighs, groin, and trunk in one operation.40 Lower body contouring is subtle compared with thighplasty and buttocks lifts, and patients must be selected carefully. It is the opinion of the authors that no more than two combined procedures should be undertaken during one operation. The risks from prolonged anesthesia and the potential for excessive blood loss outweigh any benefit from a one-stage procedure. Liposuction of the hips and greater trochanters, however, is common and may be combined with any of the preceding procedures.
The incidence of complications following abdominoplasty may be as high as 80% in obese patients.33 Because of the extent of undermining and the thick abdominal pannus encountered in the majority of these patients, they are more susceptible to seromas, hematomas, and wound dehiscence (Fig. 7). The use of drains is a necessity any time there is undermining. A suction drain on each side with puncture sites concealed at length from incisions should remain with constant suction until the daily output of each drain drops below 20 mL. Basting sutures are used to close down dead space created from the undermining. Sutures are passed from the rectus fascia to the underside of the abdominal flap to the level of Camper's fascia at the time of flap advancement. Fat necrosis is common because of the compromised blood supply to the thick pannus. Wound dehiscence may lead to exposure of mesh or AlloDerm from a hernia repair. Packing and a wound Vaccum Assisted Closure® (VAC) treatment help to facilitate healing by secondary intention. Patients must be apprised of the possible need for secondary grafts or flaps for closure. Because of imbrication of the rectus muscle, hernia recurrence is rare. Deep venous thrombosis and pulmonary embolism are known potential complications. An uncommon, but potentially lethal, complication that has been encountered during the repair of an associated hernia is severe bradycardia. It is postulated to be a result of bowel manipulation and resultant vagus nerve stimulation, and there have been cases of bradycardia leading to cardiac arrest intraoperatively. Constant communication between the surgeon and anesthesiologist is the best way to avoid lethal consequences. Obese patients who rely more on diaphragmatic descent than intercostal muscles during inspiration frequently experience respiratory compromise after significant plication of a lax abdominal wall. Close monitoring with pulse oximetry and supplemental oxygen therapy as needed should be routine postoperative care.
Patients with massive weight loss are commonplace in practice. They require challenging procedures for a variety of conditions. Their comorbidities are more numerous than those of the general population. Special considerations in regard to abdominoplasty designs have been discussed. Although we all expect this population to increase in number, we can also anticipate improved care and subsequent results.