Wound-related complications including dehiscence, necrosis, delayed healing, infection, hematoma, and seroma formation can be linked to nutritional deficiencies, which may be subclinical and unmasked by the demands of undergoing a plastic surgery procedure.⁴ With the need to optimize patient safety, there has been greater focus in the plastic surgery literature on the preoperative evaluation of the post-bariatric surgery patient, with particular attention to nutritional assessment.⁵^–⁸ Weight loss and maintenance with appropriate supplementation is no small feat after surgical weight loss, and requires compliance and psychological wellbeing. Surgical success and patient satisfaction after body contouring surgery ultimately depend upon a patient’s mood stability and capability of adopting a healthy lifestyle.

This chapter outlines the nutritional and psychological considerations in the evaluation of the massive weight loss patient. New methods of preoperative assessment and treatment protocols could materialize through thoughtful contemplation of the various risks unique to this patient population.

Nutritional Considerations for the Post-Bariatric Patient

Bariatric Surgery History

The gastrointestinal physiology of post-bariatric patients differs according to the type of bariatric procedure performed. It is therefore important to obtain a bariatric surgery history, since this will largely predict the type of nutritional deficiency for which the patient is at greatest risk.^9,¹⁰ Bariatric procedures can in general be categorized as being restrictive, malabsorptive, or a combination of both (Table 54.1). Malabsorption is achieved by bypassing a portion of the proximal small bowel, leaving less absorptive surface for ingested nutrients, whereas restriction is achieved by either reducing the size of the stomach or by placing a mechanical device to restrict food intake. Although purely restrictive procedures do not alter the normal digestive pathway, nutritional deficiencies may develop nevertheless due to restriction of caloric or nutrient intake, maladaptive eating behavior and digestive symptoms. The Roux-en-Y gastric bypass (RYGB) is considered the gold standard procedure and remains the procedure most commonly performed in the United States. This procedure has components of both restriction and malabsorption. Worldwide, experience with placement of the purely restrictive laparoscopic adjustable gastric band (LAGB) is greatest.¹¹ Approved by the FDA in 2001, the LAGB has quickly become the second most common bariatric procedure in the US, with favorable longer-term results and public perception that it is the least invasive of surgical procedures.¹²^–¹⁴

TABLE 54.1 Common Types of Bariatric Surgery Procedures Performed in the United States

	Restriction	Malabsorption
Roux-en-Y gastric bypass (RYGB)
Standard	+ +	+
Long-limb	+ +	+ +
Laparoscopic adjustable gastric band (LAGB)	+ + +
Biliopancreatic diversion (BPD)	+	+ + +
BPD with duodenal switch (BPD/DS)	+	+ +

Weight Loss History

In general, gastric bypass patients will undergo rapid weight reduction in the first 3 months, reaching a stable plateau within a 12 to 18 month period.¹⁵ Patients with the LAGB have a much slower rate of weight loss, which may not peak until 3–4 years following placement of the device.^10,^12,¹⁴ Even though many post-bariatric surgery patients will have lost in excess of 45 kg (100lbs), quite a few will plateau with a body mass index (BMI) that remains high at the time of presentation for plastic surgery. Furthermore, a significant percentage will still be classified as obese at the time of plastic surgery.^6,¹⁶ Wound-related complications that may be due to pre-existing micronutrient deficiencies found with obesity¹⁷ may therefore be further compounded by the effects of bariatric surgery, which may produce malabsorption of nutrients, bile salts and electrolytes, as well as intolerance of particular foods.

Ideally, post-bariatric patients should be within 10–15% of their goal weight at the time of evaluation for plastic surgery, fluctuating no more than a few kilos over a 3–6 month period.¹⁸ A greater decrease in BMI following bariatric surgery, increasing age, and the presence of dumping syndrome may indicate a greater risk for nutritional deficiency.⁵ Although intestinal adaptation can be expected to occur within 1–3 years with stabilization of metabolic derangements,¹⁰ the post-bariatric surgery patient remains at risk for both macronutrient and micronutrient deficiencies. Furthermore, many post-bariatric surgery nutritional deficiencies tend to worsen over time.^5,^19,²⁰ Although bariatric surgery has been in practice for at least several decades now, evidence-based guidelines regarding optimum nutritional supplementation following surgery are still lacking.⁹ Despite empiric vitamin and mineral supplementation (Table 54.2), deficiencies are prevalent in post-bariatric surgery patients presenting for plastic surgery.⁵

TABLE 54.2 Routine Vitamin and Mineral Supplements Following Bariatric Surgery ^a

Supplement	Dosage
Multivitamin	1–2 daily
Calcium citrate with vitamin D	1200–2000 mg/d + 400–800 U/d
Folic acid	400 µg/d in multivitamin
Elemental iron with vitamin D^b	40–65 mg/d
Vitamin B₁₂	≥350 µg/d orally
	or 1000 µg/month intramuscularly
	or 3000 µg every 6 months intramuscularly
	or 500 µg every week intranasally

states are treated beyond these recommendations.

From Mechanick et al¹⁰

^a Patients with preoperative or postoperative biochemical deficiency.

^b For menstruating women.

Protein

Protein deficiency is a significant risk for bariatric patients and should be of concern for plastic surgeons, since adequate serum protein levels are necessary for normal wound healing.²¹ Importantly, protein malnutrition after weight loss surgery cannot be excluded by history alone and serum concentration should be measured. Bariatric surgery can produce a combination of catabolism, malabsorption, and intolerance to protein-rich foods, leading to depletion of total body proteins.²² Protein malnutrition, in turn, may lead to increased inflammation and decreased tensile strength of surgical wounds as they heal. Large wounds from major surgery can increase protein demands for healing by 25% during the postoperative period.²³ Furthermore, low serum albumin has been shown to be a strong predictor of increased morbidity and mortality, in particular due to sepsis and major infections.²⁴ Greater decreases in BMI following bariatric surgery and the presence of dumping syndrome are found to be significant predictors of hypoalbuminema in bariatric surgery patients presenting for plastic surgery.⁵

Quantitative assessment of daily protein intake is important, since many patients will fall below 50% of the recommended daily intake of protein. Low prealbumin levels have been reported in up to 38% of post-bariatric surgery patients.^6,¹⁰ Daily protein intake for the post-bariatric surgery patient is recommended in the range of 60–120 g/day,^10,²⁵ with those preparing to undergo major body contouring or reconstructive surgery advised to consume no less than 1 g/kg/day,⁵ typically by way of supplementation. In severe cases of protein calorie malnutrition, hospitalization for hyperalimentation may become necessary.

Iron

All bariatric surgery patients are at risk for developing iron deficiency, in large part due to an intolerance to red meat, which may lead to microcytic anemia.^10,²⁰ In a population of patients presenting for plastic surgery, the most common deficiency of vitamins and minerals tested was iron at 39.7%.⁵ Menstruating women are at greatest risk and will often receive oral supplementation by way of ferrous sulfate, fumarate, or gluconate (320 mg twice a day). Vitamin C can help iron absorption and increase ferritin levels. Intravenous iron may be necessary for severe or recalcitrant deficiency.

Vitamin B12 and Vitamin B9 (Folate)

The gastric bypass patient population is at greatest risk for developing vitamin B12 deficiency, due in large part to maldigestion.²⁶ This deficiency tends to increase over time, despite oral supplementation with crystalline vitamin B12,²⁷ and may lead to macrocytic anemia and neurologic sequelae. Supplementation with oral crystalline vitamin B12 (350 µg/day) or intranasal vitamin B12 (500 µg/week) is typically provided. In cases where adequate levels cannot be maintained, parenteral supplementation (1000 µg/week or 1000 to 3000 µg every 6–12 months) may be necessary.¹⁰ Vitamin B12 status should be evaluated on an annual basis. Folate deficiency may be seen in up to 38% of gastric bypass patients, which can lead to megaloblastic anemia and an increased risk for neural tube defects during pregnancy.²⁸ In most cases, folate supplementation (400 µg/day) is adequate with the amount contained in a multivitamin preparation.

Vitamin B1 (Thiamine)

Thiamine deficiency can lead to severe neurologic compromise, including Wernicke–Korsakoff encephalopathy. Deficient states can be reached in a relatively short period of time, in particular in the post-bariatric surgery patient with protracted nausea and vomiting. Subclinical deficiency can be quickly unmasked by the routine administration of glucose-containing intravenous fluids,⁴ whereby impaired glucose metabolism may precipitate central nervous system deterioration.²⁹ A low index of suspicion should be maintained for patients presenting with vague neurologic symptoms, including weakness, numbness, forgetfulness, or with subtle signs of peripheral neuropathy on physical exam. Although adequate daily requirements are typically met with a multivitamin, patients with persistent vomiting should be screened for deficiency.¹⁰ Patients who develop neurologic signs and symptoms suggestive of Wernicke–Korsakoff encephalopathy should receive aggressive parenteral supplementation with thiamine (100 mg/day) for 1 to 2 weeks, with subsequent oral supplementation (100 mg/day) until neurologic symptoms resolve.¹⁰