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Obesity Risks in Plastic Surgery. Lip Teh Plastic Surgery December 2006. Obesity: The Epidemic. In the US: Annual deaths due to obesity: 112,000 65% adults overweight 30% obese 4% severe obesity 16% of children ages 6 to 19 years old are overweight
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Obesity Risks inPlastic Surgery Lip Teh Plastic Surgery December 2006
Obesity: The Epidemic • In the US: • Annual deaths due to obesity: 112,000 • 65% adults overweight • 30% obese • 4% severe obesity • 16% of children ages 6 to 19 years old are overweight • Obesity prevalence has increased across all education levels and is higher for persons with less education
Weight gain • Fat is deposited throughout the subcutaneous and visceral areas fairly evenly • Fat is initially accumulated in existing adipocytes • When total body fat>40kg or BMI>35 then new fat cells are produced (hyperplastic obesity). This is more resistant to dieting and exercise.
Limitation of BMI : does not provide a description regarding distribution of adipose tissue. Subcutaneous vs visceral fat mass. most accurate definition of fat distribution relies on the instrumental imaging (CT, MRI) Fat Distribution
Central obesity • mainly located in the abdomimal viscera, whereas limbs and face are often normal. • frequently associated with metabolic and vascular disorders • requires dietological, exercise, and possibly psychological therapy.
Peripheral obesity • mainly located in limbs and in regions below navel • infrequently associated with metabolic disorder • Often resistant to dieting
Diffuse obesity • most common form • consists of a homogenous increase of adipose tissue in the whole body. • ideal therapy should be a synergic approach by the dietologist, the bariatric surgeon and the plastic surgeon.
Localised obesity • rare forms of obesity, such as Barraquer-Simons Syndrome, Madelung’s disease or Launaois-Bensaude syndrome and other lipodystrophic disorders, • resistant to the dietologist or bariatric surgery.
Formerly obese • redundant cutaneous mantle secondary to massive fat loss
Bariatric Surgery • Indications: • BMI>40 • BMI> 35 who have significant comorbidities. • most effective therapy for long-term significant weight loss in morbidly obese patients. • number of procedures performed in the US increased 500% between 1993 and 2003.
Bariatric Surgery • Metaanalysis of 22,000 patients • Lipid disorders improved in 70% • Diabetes improved in 76.8% • Hypertension improved in 78.5% • Obstructive sleep apnea improved in 86% Buchwald et al, JAMA 2004
Obesity comorbidities • Hypertension • Dyslipidemia, Type 2 diabetes, Insulin resistance, glucose intolerance, Hyperinsulinemia • Atrial fibrillation, Coronary heart disease, Congestive heart failure • Stroke • Reflux oesophagitis, Gallstones, Cholecystitis and cholelithiasis • Gout, osteoarthritis • Obstructive sleep apnea and respiratory problems • Malignancies - endometrial, breast, prostate, and colon cancer • Complications of pregnancy • Poor female reproductive health (such as menstrual irregularities, infertility, and irregular ovulation) • Stress incontinence, Uric acid nephrolithiasis • Psychological disorders (such as depression, eating disorders, distorted body image, and low self-esteem)
Obesity and Surgery • Studies from multiple coronary artery bypass surgery shows: • In hospital mortality unchanged compared to normal population • Increased risk of perioperative morbidity, sternal infections, prolonged mechanical ventilation and increased length of stay
Obesity and Surgery • DVT and PE • Mechanisms • increased intra-abdominal pressure • venous stasis • hypercoagulable state (higher levels of factor VIII and factor IX, but not of fibrinogen ) • Poor mobility • Relative risk (obese vs nonobese) Am J Med 2004 • DVT – 2.5x • PE – 2.2x • In obese(BMI>25) women on OCP – 10x risk of DVT (Thromb Haemost 2003)
Obesity and Surgery • Nosocomial infection • 3x increase risk in obese • 4x increase risk in severe obese • Mostly due to increase in surgical site infection • Also increase risk of pneumonia and UTI
Obesity and Surgery • Surgical site infection • Mechanisms • decreased oxygen tension • immune impairment • tension along suture line • longer operative time • Relative risk = 2-3x
Surgical Site infection • Obesity Research 2003 • Prospective study of 395 patients in a general surgery unit
Surgical Site infection • Olsen, J Thorac Cardiovasc Surg 2002 • Retrospective study • Obesity: OR 3.1x for superficial surgical-site infection • Vilar-Compte (World J Surg 2004) • Prospective study, 280 patients in a breast oncological surgery unit • Obesity: OR 2.5x for surgical site infection
Surgical Site infection • Barber (Arch Surg 1995) • MSKC oncological service N=1226 • Surgical site infection rates were 3.8% in class I; 8.8% in class II; 20.7% in class III; and 46.9% in class IV procedures. • obesity contributed as strongly as the surgical procedure category to a patient's likelihood of acquiring a surgical site infection.
Obesity and Breast Reduction • Only 20% of women undergoing reduction mammoplasty are of normal weight • Strombeck 1964 • systemic and local complications • 4.4% for the nonobese • 13.5% for those > 10 kg overweight. • Zubowski (PRS 2000; retrospective n=395) • Major local complications (skin loss, nipple loss, abscess, and hematoma ) • 6.2% for the nonobese • 9.2% for those > 10 kg overweight. • Complications correlated with increasing weight of reduction
Obesity and Breast Reduction • Platt (Ann Plast Surg 2003 prospective n=30) • BMI > 26.3, 33% wound breakdown rate • BMI < 26.3, 10% wound breakdown rate; P < 0.05 • Wagner (PRS 2005, retrospective n=186) • no increase in the complication rate in the obese patients • O’Grady (PRS 2005, retrospective n=133) • BMI not associated with nipple necrosis, hematoma formation, fat necrosis, cyst formation, nipple sensation, or hypertrophic scarring • Higher BMI predicted a delayed healing, wound dehiscence, and infection. (relative risk 1.2x)
Obesity and Breast Reduction Summary In reduction mammaplasty, obesity leads to an increased risk (1.5-3x) of • delayed healing • wound dehiscence • infection • Stronger correlation with size of reduction
Obesity and TRAM • Paige, Bostwick PRS 1998 • Pedicled TRAM, retrospective n=257 • Obesity significantly associated with • Donor site complications • Fat necrosis • Partial flap loss • Breast mound infection
Obesity and TRAM • Chang PRS 2000 • Free TRAM, retrospective n=939 flaps (718 patients) • Flap complications: Obese vs normal weight • overall flap complications (39.1 vs 20.4%;p = 0.001), • total flap loss (3.2 versus 0%;p = 0.001) • flap seroma (10.9 versus 3.2%;p = 0.004) • mastectomy flap necrosis (21.9 versus 6.6%;p = 0.001). • Flap complications: Overweight vs normal weight • overall flap complications (27.8 versus 20.4%;p = 0.033) • total flap loss (1.9 versus 0%p = 0.004) • flap hematoma (0 versus 3.2%;p = 0.007) • mastectomy flap necrosis (15.1 versus 6.6%;p = 0.001)
Obesity and TRAM • Donor complications: Obese vs normal weight • overall donor-site complications (23.4 versus 11.1%;p = 0.005) • infection (4.7 versus 0.5%;p = 0.016) • seroma (9.4 versus 0.9%;p <0.001) • hernia (6.3 versus 1.6%;p = 0.039). • Donor complications: Overweight vs normal weight • overall donor-site complications (19.8 versus 11.1%;p = 0.003) • infection (2.4 versus 0.5%;p = 0.039) • bulge (5.2 versus 1.8%;p = 0.016) • hernia (4.3 versus 1.6%;p = 0.039)
Obesity and TRAM • Moran PRS 2001 • Free vs Pedicled TRAM, retrospective n=114 • no significant difference in the overall complication rates • Free TRAMs: 14% of nonobese, 17% of moderately obese, and 33% of severely obese (p=0.08) • Pedicled: 27%, 37% and 29% (not significant) • Overall, free TRAM flap reconstructions had a lower incidence of partial flap loss. • enhanced blood supply, dominant DIEA vessel • more freedom in positioning the flap
Obesity and TRAM • Wang PRS 2005 • Retrospective study n=107, delayed pedicle • nonflap complications increased with increasing obesity (8 vs 31.6%) • no difference in flap related complications between obese and nonobese groups after delayed pedicled TRAM
Obesity and TRAM Summary • In TRAM reconstructions, obesity leads to an increased risk of • Flap complications (2x) • Donor site complications (2x) • Systemic complications • Risks reduced with free TRAM or delayed pedicled TRAM
Obesity and Abdominoplasty • Vastine (Ann Plast Surg 99) • Retrospective study, n=90 • 80% of obese patients had complications compared with the borderline and nonobese patients, who had complication rates of 33% and 32.5% respectively • Previous gastric bypass surgery had no significant effect on the incidence of postabdominoplasty complications.
Obesity and Body Contouring • Taylor (Obese Surg 2004) • Retrospective study, n=30 post massive weight loss • Overall morbidity 42% • 20% wound breakdown • 17% seroma • 1 patient died from PE • Challenging surgery requiring individualized approaches with intensive follow-up.
Obesity and Body Contouring • Sanger (Ann Plast Surg 2006) • Retrospective study, n=26 post massive weight loss • 27% wound complications(seromas, hematoma, infection, and fat necrosis) • increase in wound complications attributed to the inherent complications seen with obese patients.
Obesity and Body Contouring Summary • Preliminary evidence suggests that incidence of local complications in body contouring operations remain unchanged despite weight loss.