Post-bariatric reconstruction

30 Post-bariatric reconstruction






History


Throughout history, the definition of beauty has changed and evolved, not only with time, but also across societies and cultures. Western society is no exception. From the full-figured ideals of Venus of Willendorf to the extremely thin models of the 1960s such as Twiggy, the ideal body weight and shape has varied. With today’s trends of revealing women’s clothing coupled with societal pressures from the media to be thin, there is more pressure than ever before to maintain a fit and thin body shape.1


More sedentary lifestyles and a diet rich in fats have led to a preponderance of obesity in North America and the rest of the world.2,3 The evolution of bariatric surgical procedures has been designed to improve upon obesity and its related chronic health issues. Body contouring has also evolved, with the introduction and eventual widespread popularity of liposuction and the increasing acceptance of more aggressive excisional procedures.4,5 The emergence of the MWL patient has forced plastic surgeons to re-evaluate traditional methods of body contouring and to devise innovative techniques in order to deal with more challenging deformities.



Obesity



Definition and epidemiology


Overweight and obesity refer to ranges of weight that are greater than that generally considered healthy for a given height. The primary measurement for obesity used to categorize patients is the body mass index (BMI).6 According to the World Health Organization (WHO), overweight is defined as a BMI between 25 and 29.99 kg/m2. Obesity begins at 30 kg/m2 with obese class I equivalent to 30–34.99 kg/m2.7 Modifications to the classification have been added, including the categories of super obese (50–60 kg/m2), and super, super obese (>60 kg/m2) (Table 30.1).8


Table 30.1 BMI and obesity classification7,8






























BMI (kg/m2) Classification
<18.5 Underweight
18.5–24.9 Normal weight
25.0–29.9 Overweight
30.0–34.9 Class I – Obesity
35.0–39.9 Class II – Obesity
40.0–49.9 Class III – Morbid obesity
50.0–59.9 Class III – Super obesity
≥60.0 Class III – Super, super obesity

In the United States, obesity is increasing at an alarming rate.9 In 2008, the prevalence of obesity among American adult men and women was 32.2% and 35.5%, respectively. However, the prevalence of overweight and obesity combined was an alarming two-thirds of the adult population.3 Approximately 5% of the American population is considered morbidly obese.10 A rise in obesity among children and adolescents has also been noted in the past three decades.9 Worldwide, the overweight and obesity population is estimated to be approximately 1.7 billion people.11


Obesity is an independent risk factor not only for all-cause mortality, but also for major diseases including coronary heart disease, type II diabetes, hypertension, certain malignancies, and musculoskeletal disorders.2 One cannot ignore the psychosocial ramifications of obesity.12 Disturbingly, obesity is predicted to overtake smoking as the leading cause of death in the United States.13 Not only does obesity result in lower societal productivity and higher healthcare costs, rises in patient morbidity and mortality have spurred governmental interventions.1416


The etiology of obesity is more complex than originally thought. Although some simplify the problem to “more calories in than out”, other factors, including genetics, environment, and psychological factors are influential.12 Certain medical conditions may also play a role: Cushing’s disease, hypothyroidism, systemic steroids all cause increases in weight.


Notoriously difficult to treat, obesity is often resistant to many forms of therapy. Gastric bypass procedures have been shown to provide cost-effective, durable long-term weight control in the moderately to morbidly obese.17,18 Improvements in safety as well as a decrease in morbidity associated with bariatric surgery have led to a concomitant rise in bariatric surgical procedures, resulting in growing numbers of patients seeking removal of the excess skin and fat remaining following weight loss.19,20


MWL from surgery or diet and exercise alone, may be described as weight loss in excess of 50 pounds. Plastic surgeons have had to modify traditional surgical approaches and techniques in order to appropriately treat the unique deformities found in this emerging patient population.



Methods of weight reduction



Diet and exercise


Diet and exercise play an integral role in any weight loss regimen. Simplified, in order to lose weight, caloric intake must be less than total body expenditure of energy in order to consume endogenous triglycerides.21 Caloric restriction may take the form of generalized reduction in calories, but may be aided by adjustments in the types of macronutrients eaten (e.g., fats, carbohydrates).22,23 A recommended diet of between 1000 and 1200 kcal/day for women, and 1200–1600 kcal/day for men is commonly followed for a target weight loss of 1–2 pounds per week. In most cases, an initial weight loss of 10% of body weight over a 6-month period is suggested.24 Unfortunately, long-term studies have found diet therapy alone is ineffective in the treatment of obesity.24,25


Often coupled with a reduction in caloric intake is physical activity or an exercise regimen. Physical activity is valuable, primarily aiding in long-term weight loss maintenance.26,27 Isolated physical activity with no changes in a high calorie diet is insufficient to cause significant amounts of weight loss.28



Pharmacotherapy


The anorectic agents fenfluramine and phentermine have both in the past, been approved by the Food and Drug Administration (FDA) as individual agents. However, these drugs are not commonly used to treat obesity due to associations with the development of primary pulmonary hypertension and valvular heart disease.2932


Currently, weight loss drugs are approved by the FDA for patients that have a BMI ≥ 30 kg/m2, or a BMI between 27 and 29.9 kg/m2 in conjunction with an obesity-related medical complication.21 The majority of weight loss medications are anorexiants. Most are only approved for short-term use, and patients typically regain weight once discontinued.33


Two drugs are approved for long-term treatment of obesity. Orlistat (Xenical), a noncentrally acting anti-obesity agent, inhibits triglyceride digestion in the gastrointestinal tract. In combination with a hypocaloric diet, Orlistat promotes weight loss over a 1-year period.34 Adverse effects of orlistat are primarily gastrointestinal with complaints of oily stool (including fat-soluble vitamin malabsorption) and fecal incontinence.35 Sibutramine (Meridia) inhibits the reuptake of neurotransmitters in the brain, thereby increasing satiation. Weight loss in clinical trials with sibutramine has been shown to be greater than with placebo alone.36,37 Currently, there are no pharmacologic anti-obesity agents that are truly effective against morbid obesity.24,25



Bariatric surgery


Bariatric surgery in the morbidly obese has been shown to ameliorate, and even cure some chronic diseases that have long been considered refractory to medical management. Perhaps the most profound effect of bariatric surgery is the reduction in type II diabetes. In 1995, a landmark study by Pories et al. was the first to report significant improvements in glucose control following bariatric surgery.17 Further studies have demonstrated 83% and 86% resolution rates of type II diabetes following bariatric surgery.38,39 Diabetes resolution was found to occur only days following surgery, well before weight loss was achieved.17


Diabetes is not the only disease improved by bariatric surgery. Sjostrom et al., demonstrated that hyperlipidemia was lowered by 10-fold following either gastric bypass, gastroplasty, or gastric banding as compared with controls.40,41 Hypertension and sleep apnea have also been shown to improve following bariatric surgery.10 Increases in life expectancy have been noted in patients following weight loss.40,42,43 Bariatric surgery results in durable and stable weight loss within 1 year following surgery, that is three to four times superior to that achieved with nonsurgical treatment.10,44


Indications for bariatric surgery as a treatment of obesity include: BMI >40 kg/m2, or BMI between 35 and 40 kg/m2 with a high-risk comorbid condition, failed medical management, multidisciplinary evaluation, a motivated and well-informed patient with realistic expectations, and a commitment to long-term follow-up.4547


Multiple surgical techniques have been described to treat obesity. The plastic surgeon should understand the various procedures and the effects they may have. Three main categories exist: restrictive, malabsorptive, and a combination restrictive malabsorptive.


Restrictive procedures produce satiety with the surgical creation of a small gastric pouch with a restricted outlet, thereby restricting food intake.48 The advantage to restrictive procedures is the reduction in the malabsorption of nutrients seen long-term in malabsorptive procedures. Vertical banded gastroplasty involves the creation of a circular window made in the stomach a few inches below the esophagus. A small vertical pouch is made. Complications include esophageal reflux, stomal narrowing or widening, and less successful results with stable weight loss compared with gastric bypass, which has caused this procedure to fall out of favor.4952


The more popular purely restrictive bariatric surgery is laparoscopic adjustable gastric banding (LAGB), where a band is placed around the upper stomach 1–2 cm below the gastroesophageal junction, creating a 20–30 cc upper gastric pouch.50 The degree of constriction is adjusted with the alteration in the amount of saline in the band through the subcutaneous port. Because the absorptive surface of the gastrointestinal tract is unaltered, there is a decreased risk of nutritional deficiencies. Excess weight lost ranges from 52% to 68%.5356 The disadvantages of LAGB are less weight loss compared with combination restrictive malabsorptive procedures and a permanent intraabdominal foreign body. One of the most serious complications of LAGB is erosion of the device into the stomach, requiring surgical intervention, including removal of the band.57 As evidence accumulates regarding the safety and efficacy of LAGB, it is anticipated that the use of these devices will dramatically increase.51,58


Purely malabsorptive procedures divert nutrients and interrupt the digestive process. More common techniques involve both restrictive and malabsorptive mechanisms, rather than malabsorption alone. Biliopancreatic diversion (BPD) has evolved to include a limited gastrectomy to reduce stomach size, as well as the creation of a malabsorptive limb, with a 50 cm common channel for absorption. Major complications from BPD include protein-calorie malnutrition, anemia, and bone demineralization.49,50,52 Although the greatest degree of malabsorption occurs with this procedure, there is also a risk of stomal ulcer formation, frequent and foul smelling stools, and dumping syndrome.57,59


Currently in America, the most popular bariatric surgical procedure is the gastric bypass, or roux-en-Y gastric bypass (RYGB). Both the size of the stomach and the gastric outlet are restricted. This is a restrictive and malabsorptive combination procedure in which the degree of malabsorption is determined by the length of the jejunum attached to the gastric outlet.60 Many variations of RYGB are possible.


Late complications of bariatric surgery are most relevant to the plastic surgeon.57 These include inadequate weight loss, psychiatric conditions, dumping syndrome, and most importantly, nutritional deficiencies.49,59,61 Adequate calorie intake and nutrition is the cornerstone of postoperative healing. Folate, calcium, vitamin B12, and iron deficiencies may be seen following bariatric surgery. Daily supplemental vitamins reduce the risk of neurological and hematologic complications.62 The incidence of peripheral neuropathy following bariatric surgery was 16% in one study.63 A summary of the advantages and disadvantages of various methods of weight loss are shown in Table 30.2.


Table 30.2 Advantages and disadvantages of various methods of weight loss



































Method of weight loss Advantages Disadvantages
Diet and exercise

Pharmacotherapy

Bariatric surgical procedure

 VBG

 LAGB

 BPD

 RNYGB


VBG, vertical banded gastroplasty; LAGB, laparoscopic adjustable gastric banding; BPD, biliopancreatic diversion; RNYGB, Roux-en-Y gastric bypass.



Diagnosis/presentation/evaluation



History


Patient evaluation includes a complete medical history. A distinction must be made in the mode of weight loss. Key information to obtain regarding the patient’s weight includes:



Other important history required includes:



Many patients will have had numerous medical co-morbidities prior to weight loss, that have improved significantly or since resolved. These benefits commonly occur within 2–5 months following bariatric surgery.65 Sequelae of gastric bypass must also be assessed, including history of past or current dumping syndrome, or prolonged emesis.


Screening for nutritional status is important.66 Protein intake by history is considered adequate if 70–100 g of protein per day is reported, although serum protein measurement is indicated before post-bariatric body contouring. Following bariatric surgery, protein is one of the major nutrients affected and may be reflected as hypoalbuminemia, anemia, and edema. Although seen in Roux-en-Y gastric bypass, the most common procedures associated with protein deficiencies are malabsorptive in nature such as the biliopancreatic diversion.46,66 Protein intake is essential for wound healing especially if multiple contouring procedures are performed. Pre-albumin and albumin levels elucidate issues with protein intake and absorption. Protein supplementation may be required preoperatively.


Deficiencies in nutrients and vitamins, such as thiamine, folate, B12 and iron are common.67,68 A history of current or past supplementation may screen for this. Nutritional deficiencies are most common in malabsorptive procedures including Roux-en-Y gastric bypass and biliopancreatic diversion.66


Anemia is not uncommon in the MWL population and may be related to generalized or specific nutrient deficiencies. Although iron deficiency is most common, micronutrients such as B12, folate, copper, fat-soluble vitamins A and E, or zinc may be deficient and contribute to anemia.69,70 A complete hematological work-up, including measurement of iron stores should be performed, especially in high-risk patients. In some cases, iron deficiencies may be refractory to oral therapies and require more aggressive treatment with parenteral iron, blood transfusions, or surgical interventions.67 Iron deficiency may be seen in association with any gastric bypass procedure.



Physical examination


A generalized physical assessment of the degree of skin excess, distribution of fat, number and location of rolls, and the quality and elasticity of the remaining skin indicates which areas of the body would benefit from contouring surgery. Characteristically patients will present with predictable patterns of tissue descent around the body.


Zones of adherence, which are tight, nonyielding areas of fascial attachment to the underlying muscular system act as tethering points from which skin laxity will hang. These areas of restriction are located in the midline of the anterior and posterior trunk, and around the pelvic rim. Areas of skin and soft tissue that are farthest in distance from the zones of adherence descend the most following MWL, which in most patients includes the lateral truncal tissues.71 The estimated skin resections may be simulated by performing “pinch tests”, which may also help determine the translation of pull (distance from the pinched area that tissues are affected).72


Scars from prior surgeries are important to document, as a reduction in blood supply may require technical modifications during surgery. Commonly, rectus diastasis may be discovered. Ventral hernias are reducible or nonreducible, and the edges of the hernia may be palpated. A breast examination should be performed, noting masses, position of the nipple areola complex, and skin envelope quality. Asymmetries are pointed out to the patient. Lateral thoracic skin rolls are noted. Standardized photographs are taken.




Patient preoperative counseling and education


Preoperative counseling exploring the patient’s goals, expectations, and areas of greatest concern aids in patient selection. Patients are questioned on areas of the body of greatest priority requiring correction, especially when multiple procedures are performed. Education regarding the areas of the body that may be contoured concurrently and discussion as to the appropriate staging of procedures is undertaken.


Patients must be made aware of the lengthy scars that occur with large skin resections, and must be willing to trade a better contour with the resultant scar. Although gentle tissue handling, meticulous wound closure and postoperative scar therapies attempt to create inconspicuous scars, some incisions tend to heal with raised, reddened, or even hypertrophic scars.


Education must focus on pre- and postoperative expectations, the length of the surgical procedures, as well as the nature and length of recovery following multiple procedures. As the majority of surgeons use drains in the initial postoperative period, information regarding drain care should be given. Patients must have appropriate social support at home in order for a smooth recovery to occur. No lifting of items heavier than 10 pounds is a good rule of thumb for patients undergoing abdominal procedures.


Abstinence from medications that predispose to bleeding, including herbal medications is important. Tobacco use is a relative or absolute contraindication for body contouring by most surgeons. Smoking cessation helps to minimize flap loss and wound complications such as dehiscence and infection.74,75 Although there is no consensus, a commonly used guideline is abstinence from tobacco or nicotine replacement therapies for at least 4 weeks prior to and 4 weeks post-elective cosmetic or reconstructive procedures.76


Informed consent is a key element of preoperative counseling. Patients must understand that body contouring after MWL may require multiple stages, and possible revisionary surgeries. The surgeon’s revision policy must be emphasized to patients and the difference between secondary procedures (further skin tightening) and revisions understood. In general, MWL patients experience mild to moderate amounts of skin relaxation postoperatively, resulting in the need for further skin resections. There is also the possibility of contour irregularities and postoperative “dog-ears” at the extents of resection. A comprehensive guide to informed consent in body contouring patients following MWL is available from the American Society of Plastic Surgeons.77



Patient selection


Patients presenting following MWL should be at or around their goal weight, and be weight-stable for at least 3 months prior to body contouring surgery. This usually corresponds to a period of 12–18 months following bariatric surgery. A BMI <35 kg/m2 is acceptable; a BMI >35 kg/m2 portends increased risk of surgical complications.7880 Ideally, patients undergoing body contouring after MWL should be within 10–15% of their goal weight and have had no large fluctuations in their weight (weight-stable) over the past 3–6 months.48


Aesthetic outcomes are improved with a lower BMI. In general, a BMI of 25–30 kg/m2 is ideal, and patients with a BMI >32 kg/m2 may have more limited aesthetic outcomes.81,82 Also, a high BMI increases the rate of complications, especially thrombotic complications such as deep venous thrombosis.83,84 Patients with high BMIs are counseled to further lose weight and return again at a more ideal BMI. A notable exception to this guideline is the patient with the disabling giant pannus, or panniculus morbidus. These patients will generally benefit from the removal of abdominal excess in order to improve ambulation, quality of life, hygiene, and further their weight loss.85


Patients with severe medical co-morbidities, psychiatric co-morbidities, unrealistic expectations, and patients currently using tobacco are preoperatively optimized. These issues are reassessed at the second preoperative visit and surgical management is offered only once improved or resolved.


The authors consider systemic medical disease that precludes general anesthesia an absolute contraindication for body contouring surgery. Relative contraindications include active smoking, BMI >35 kg/m2, uncorrected coagulopathies, severe disorders that affect wound healing, and systemic medical disease that place the patient at high risk for surgery.



Psychological considerations



Post-bariatric body contouring


MWL is considered by many to be a “life-altering event”. Such is the same with body contouring procedures. Patients should be congratulated on their weight loss. Pre- and postoperative counseling as to the usual postoperative course is essential. Family and social supports aid in the recovery period.


Prior to bariatric surgery, up to one-third of patients have at least one psychiatric diagnosis; approximately 40% of patients undergoing bariatric surgery are undergoing some form of psychiatric treatment.86,87 Mood disorders, personality disorders, and poor body image are most common. Patients with a history of bipolar disorder and schizophrenia must be offered surgery with caution. A high index of suspicion must be maintained with liberal preoperative psychiatric clearances. Following MWL, many psychiatric conditions reportedly improve, albeit transiently.88 Quality of life, however, has been found to improve following body contouring surgery, independent of mood.89



Patient safety and intraoperative considerations


Any body contouring surgery should be performed in a fully accredited ambulatory care facility or hospital. An operating room staff familiar with body contouring is essential for efficiency and timeliness of the surgery. Anesthesiologists should be familiar with the post-bariatric patient and sensitive to the physiological and structural changes that are associated (Table 30.3).90


Table 30.3 Safety and intraoperative considerations in body contouring







Prevention of hypothermia is crucial. With lengthy procedures involving the creation of large wounds, exposing the majority of the patient’s body, all patients must be monitored carefully. A temperature of at least 35oC should be maintained. The authors perform pre-warming for all body contouring patients in the pre-anesthesia holding area with forced-air warming blankets. Warming continues in the operating room with elevated basal room temperatures, forced-air blankets, warmed fluids if needed, and operating table warming pads.


Venous thrombosis prevention is integral. Surgeries are lengthy and abdominal wall tightening or reconstruction is common, elevating intra-abdominal pressures and predisposing to deep vein thrombosis (DVT) and pulmonary embolism. A preoperative history for risk factors for DVT and careful prophylaxis reduces these rates. Factors such as increased age, malignancy, history of spontaneous miscarriages, inherited or acquired thrombophilia, use of exogenous estrogens, pregnancy, and previous venous thromboembolism should alert the plastic surgeon of increased risk.9193


Guidelines from the American College of Chest Physicians in prevention of DVT are available.94 Early ambulation, mechanical lower extremity compression devices applied pre-induction, and prophylactic doses of blood thinners may be used.91 Improved efficacy does not occur when chemoprophylaxis is given preoperatively compared to within 6–12 h of the surgery. However, a higher risk of bleeding occurs when given within 2 h of surgery.95 Currently, no clear evidence based guidelines for chemoprophylaxis in the plastic surgery population exist.


Patient positioning may improve the ease of surgery and prevent untoward complications secondary to pressure. Prone positioning is often required and pressure must be minimized to points such as the breasts, genitals, and face. Endotracheal tube positioning must be maintained. Compression on the eyes must be avoided, as blindness has been reported following prone positioning.96 When prone, patients should be placed in 15o of Trendelenburg to prevent excessive pressures on the globes.97,98 Neural and vascular compression may occur.99


Length of surgery is an important consideration. Combining multiple body contouring procedures is frequent and can significantly increase operative time. Time is increased when turning the patient is required. There is no consensus on the time limits for body contouring surgery. However, fewer procedures performed and less operative time generally result in a lower complication rate.



Surgical techniques by anatomic region



Abdominal contouring


Abdominoplasty procedures are explored in Chapter 25. Abdominoplasty is reviewed here with specific reference to the MWL patient (see Box 30.1).



Feb 21, 2016 | Posted by in General Surgery | Comments Off on Post-bariatric reconstruction

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