1. Obesity Risks in Plastic Surgery Lip Teh Plastic Surgery December 2006

2. 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

3. 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.

4. Classification

5. Fat Distribution 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)

6. 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.

7. Peripheral obesity  mainly located in limbs and in regions below navel  infrequently associated with metabolic disorder  Often resistant to dieting

8. 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.

9. 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.

10. Formerly obese  redundant cutaneous mantle secondary to massive fat loss

11. 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.

12. Bariatric Surgery Metaanalysis of 22,000 patients 1.Lipid disorders improved in 70% 2.Diabetes improved in 76.8% 3.Hypertension improved in 78.5% 4.Obstructive sleep apnea improved in 86% Buchwald et al, JAMA 2004

13. 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)

14. 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

15. 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)

16. 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

17. Obesity and Surgery Surgical site infection –Mechanisms decreased oxygen tension immune impairment tension along suture line longer operative time –Relative risk = 2-3x

18. Surgical Site infection Obesity Research 2003 –Prospective study of 395 patients in a general surgery unit

19. 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

20. 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.

21. 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

22. 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)

23. Obesity and Breast Reduction Summary In reduction mammaplasty, obesity leads to an increased risk (1.5-3x) of 1.delayed healing 2.wound dehiscence 3.infection –Stronger correlation with size of reduction

24. 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

25. Obesity and TRAM Chang PRS 2000 –Free TRAM, retrospective n=939 flaps (718 patients) –Flap complications: Obese vs normal weight 1.overall flap complications (39.1 vs 20.4%;p = 0.001), 2.total flap loss (3.2 versus 0%;p = 0.001) 3.flap seroma (10.9 versus 3.2%;p = 0.004) 4.mastectomy flap necrosis (21.9 versus 6.6%;p = 0.001). –Flap complications: Overweight vs normal weight 1.overall flap complications (27.8 versus 20.4%;p = 0.033) 2.total flap loss (1.9 versus 0%p = 0.004) 3.flap hematoma (0 versus 3.2%;p = 0.007) 4.mastectomy flap necrosis (15.1 versus 6.6%;p = 0.001)

26. Obesity and TRAM –Donor complications: Obese vs normal weight 1.overall donor-site complications (23.4 versus 11.1%;p = 0.005) 2.infection (4.7 versus 0.5%;p = 0.016) 3.seroma (9.4 versus 0.9%;p <0.001) 4.hernia (6.3 versus 1.6%;p = 0.039). –Donor complications: Overweight vs normal weight 1.overall donor-site complications (19.8 versus 11.1%;p = 0.003) 2.infection (2.4 versus 0.5%;p = 0.039) 3.bulge (5.2 versus 1.8%;p = 0.016) 4.hernia (4.3 versus 1.6%;p = 0.039)

27. 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

28. 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

29. Obesity and TRAM Summary In TRAM reconstructions, obesity leads to an increased risk of 1.Flap complications (2x) 2.Donor site complications (2x) 3.Systemic complications Risks reduced with free TRAM or delayed pedicled TRAM

30. 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.

31. 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.

32. 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.

33. Obesity and Body Contouring Summary Preliminary evidence suggests that incidence of local complications in body contouring operations remain unchanged despite weight loss.