Surgery for morbid obesity

Transcription

1 Surgery for morbid obesity Stephen Pollard Consultant Surgeon St James s University Hospital Medicine for members Thackray Medical Museum April 2016

2 Classification by Body Mass Index (BMI; kg/m 2 ) <18 underweight desirable overweight obese with med problems or >40 morbidly obese >50 superobese >60 super-super obese >70 ultra-obese

3 BMI = wt/ht 2 What is BMI? Weight is proportionate to mass which is a function of volume not area Volume = height x width x breadth Persons of shorter stature have a disproportionately higher BMI Adopted for medical use from furniture manufacturers

4 Recent history where are we now? Prevalence of obesity: Male Female Overall, 3% of adults are morbidly obese 30-50,000 deaths attributed to obesity per annum 1.2 million fulfil NICE criteria for surgery

5

6 European Charter on Counteracting Obesity (WHO) Recognised surgery as the only effective treatment for morbidly obese patients Reported European data: 150,000,000 obese adults 15,000,000 obese children 1,000,000 deaths per annum

7 The size of the problem worldwide >1 billion people are overweight >Quarter of a billion are obese 2016: More people now suffer from obesity than from malnutrition Obesity is escalating in countries with a previously low incidence as they adopt Western diet such as Japan.

8 The cost of obesity In the UK 50,000 deaths per year (Registrar General) = 1 every 12 minutes Quoted healthcare costs of billion per year likely to be an under-estimate

9 Indirect costs are not just due to loss of productivity

10 Socio-economic class % of adult population with BMI>30 SE class 1 5 Male Female 14 28

11 Even our dogs are getting fatter

12 The future of bariatric surgery Predictions are risky, particularly when made about the future Senator Dan Quayle, Former U.S. Vice President

13 Obesity in Children 8.5% of 6 year olds are obese 15% of 15 years olds are obese 90% of obese children become obese adults But Average intake of calories per meal has remained unchanged since 1945 So what has changed? Snacking on energy dense high calorie foods between meals and a more sedentary lifestyle % of children walked or cycled to school % of children walked or cycled to school Dec 2006 NICE consider children suitable for surgery

14

15

16 Weight is regulated with great precision. For example, during a lifetime, the average person consumes at least 60 million kcal. A gain or loss of 10Kg, representing approximately 90,000 kcal, involves an error of no more than 0.001%. The results of adoption and family studies show a heritability of obesity of about 33%. Genetic influences may be more important in determining regional fat distribution than total body fat, particularly the critical visceral fat depot.

17 The issues of obesity What has history told us? Mixed messages

18 Idolised as a thing of beauty, prosperity and health

19

20 A sign of good health

21

22

23

24 Cardiac risk of obesity Based on Framingham Heart Study Risk of death within study period (26 yrs) increases by: 1% per pound overweight for year olds 2% per pound overweight for year olds BMI equates to 3 years loss of life BMI >30 equates to 7 years loss of life BMI >40 equates to 15 years loss of life 10 BMI units equate to 20 cigarettes per day (cardiac + cancer risk)

25 Risk of type 2 diabetes In males increase waist from <87.5cm to >101.6cm increases risk of type 2 diabetes 12 fold If BMI>25, risk increases 5 fold If BMI>35, risk increases 93 fold

26

27 Obesity Related Comorbidity Diabetes mellitus Hypertension Dyslipidaemia Some cancers uterus, ovary, cervix, colon, prostate, lower oesophagus Hypoventilation syndromes (OHS and OSA) Asthma Gastro-oesophageal Reflux Gallstones and NAFLD Osteoarthritis Abdominal wall herniae Neurological disorders Androgenisation, polycystic ovaries and infertility Psoriasis Venous stasis and varicose veins Affective disorders

28

29

30 Pickwickian Syndrome Comprises 2 syndromes: Obesity Hypoventilation Syndrome Obstructive Sleep Apneoa They often occur together some degree of overlap but 2 distinct conditions

31 Obesity Hypoventilation Syndrome Restrictive ventilatory failure Characterised by daytime hypoxia due to alveolar hypoventilation reduced ventilatory excursion Progresses to respiratory failure and right heart failure Diagnosed by arterial blood gas measurement PaO2< or = 7.3 kpa (55 mmhg)

32 Obstructive Sleep Apnoea Periods of hypoventilation/apnoea whilst sleeping Caused by airway narrowing and collapse when asleep, reduced ventilation from weight of chest and some central suppression of ventilation Characterised by snoring, waking headache from CO2 retention, and daytime sleepiness Diagnosed by polysomnography (sleep studies) apnoea/hypopnoea index (AHI) 30% of RTAs due to falling asleep at the wheel DVLA regards untreated sleep apnoea a contra-indication to driving.

33

34

35 Non-Alcoholic Fatty Liver Disease 2015: NAFLD has now overtaken alcohol and hepatitis C as commonest cause of cirrhosis in the UK. and we are not drinking less Spectrum from bland steatosis (ok) to steatohepatitis (bad)

36 Risk factors for Steatohepatitis (non-alcoholic fatty liver disease) Male sex Central obesity with high waist/hip ratio Hyperlipidaemia Diabetes with insulin resistance In the obese, alcohol increases risk of FLD up to 5 fold

37

38

39 Weight Loss What s the point?

40

41 Weight loss How to do it

42

43

44

45

46 Orlistat (Xenical, Alli) Not absorbed lumenal lipase inhibitor Prevents absorption of around 30% of ingested fat. Causes weight loss by malabsorption and behaviour modification as oral fat will induce bloating, steatorrhoea and faecal incontinence. Theoretical concern about fat soluble vitamin absorption (A, D, E and K) Average 10% weight loss in 12 month; weight loss may not be maintained when it is stopped. Other drugs e.g. Fenfluramine (Adifax, Ponderax), Sibutramine (Reductil), Rimonabant (Acomplia) have all now withdrawn on safety grounds

47 Bariatric surgery Origin: Greek Baros, weight or pressure + iatreia, medical treatment

48 Technology Appraisal: Nice Recommendations (1) Reported July 2002; reviewed 2006; Consider surgery if BMI>40, or >35 with significant comorbid conditions that could be improved by weight loss Recommend surgery provided that: Have been receiving treatment in a specialised obesity clinic Over 18 years old* Evidence that all appropriate non-surgical measures have been tried but have failed to maintain weight loss** No specific clinical or psychological contra-indication to surgery Fit for anaesthesia and surgery Understand the need for long term follow-up *revised in Dec 2006 to physiologically mature **revised in Dec 2006 to unless BMI>50

49 Technology Appraisal: Nice Recommendations (2) Only undertake surgery after comprehensive multidisciplinary assessment Arrangements to be made for support and counselling Choice of surgical procedure not specified base decision on facilities, equipment available and experience of surgeon Establish database NBSR (through BOMSS)

50 Surgery for obesity

51 Surgical techniques Broadly, surgical procedures for morbid obesity are divided into restrictive, malabsorptive and combined procedures. Approx 7000 undertaken in the UK per annum 250,000 per year in the US ( 6 x population of UK)

52 Jejuno-ileal bypass Kremen & Linner 1954

53 Jejuno-ileal bypass Works purely by impairing absorption Many reports of good weight loss appeared in 1970 s BUT Major long term problems with diarrhoea, fluid and electrolyte disturbances, and excessive weight loss with protein calorie malnutrition Dermatitis and arthritis (?blind loop syndrome) Gallstones and renal calculi Liver failure profound steatohepatitis 10% mortality led to stomach stapling procedures to reduce intake

54 Stomach stapling Vertical banded gastroplasty

55 Problems with the vertical banded gastroplasty Unbanded, the restriction is short lived as the pouch and outlet stretch Band causes scarring and narrowing of outlet, vomiting and staple line disruption

56 Led to Roux-en-Y gastric bypass Gastric restriction Modest degree of malabsorption Hypoglycaemic dumping in response to refined carbohydrates

57 Roux-en-Y gastric bypass Generally performed laparoscopically Need to take supplements (iron, vit D, B12 injections) Low maintenance Risk of anastomotic leak, stomal ulcers at new gastric outlet (bleed or stenose), internal hernias Can run into problems of malnutrition if vomiting/non compliant

58

59 Laparoscopic Band (1) Laparoscopically inserted balloon catheter to encircle upper stomach Subsequent inflation of balloon in steps to create a small gastric pouch with controlled but adjustable outlet Works by gastric restriction alone

60

61

62 Laparoscopic Band(2) Good safety record; minimally invasive, and little tendency to nutritional deficiencies Relatively high maintenance Up to 30% fail to lose adequate weight (40% in adolescents). Requires good compliance from patient 10-15% end up being removed? issues with flying and pregnancy Relatively high re-operation rate Band slippage Band erosion through stomach wall Port site infection/ulceration

63

64

65

66 Sleeve gastrectomy

67 Sleeve gastrectomy Employed as first stage of DS, or as a stand alone procedure Laparoscopic (or open) Risk of post-op staple line leakage Purely restrictive No adjustment or maintenance needed Tube diameter crucial to prevent dilatation Tendency to weight regain after 2-3 years

68 Sleeve gastrectomy/ds

69 DS Combines a sleeve gastrectomy with biliopancreatic bypass Can be performed as 1 or 2 stage operation Greater weight loss than gastric bypass Creates significant malabsorption Can eat more than with a gastric bypass No dumping as gastric outlet is preserved ( duodenal switch ) Greater risk of malnutrition and diarrhoea Greater need for compliance with high protein diet and supplements

70 Intra-gastric balloon BIB (Bioenterics Intra-Gastric Balloon)

71 BIB - Complications Bleeding / perforation during insertion Vomiting / Aspiration pneumonitis Gastric erosions Migration and obstruction Weight regain if stand alone treatment 48% of patient unsatisfied or very unsatisfied

72 Aftercare (1) Dietary choices high protein, low fat, low carbohydrate, similar to South Beach Diet. May struggle with fibrous meat early on, and long term with band Dietary habits avoid snacking between meals and excess alcohol Supplements assume they will be needed long term Follow-up at least 2 years; systems now in place to manage defaulters Measure Ferritin, B12, trace elements, LFTs Exercise -

73 Making the right choices

74

75 Exercise

76

77 Exercise Need to keep doing it

78 What happens to all the loose skin? Cosmetic surgery rarely available on the NHS and needs to be passed by the Cosmetic Exclusions Panel, as medically necessary with BMI stable and under 30.

79

80

81

82

83 Results excess weight loss, treatment failure and resolution of type 2 diabetes Procedure EWL TF T2DM LAGB 49% 30% 57% SG 54% 15% 58% RYGBP 63% 15% 80% DS 73% 10% 90% (Systematic review, Buchwald, Am J Surg 2009; )

84 Impact on Diabetes Bariatric surgery alters energy balance Independent metabolic benefit? Through incretins and other hormonal/neural changes Meta-analysis 135,000 patients; 621 studies 103 studies report remission of type 2 diabetes of 78.1% Only one randomised study investigating bariatric surgery versus no surgery for type 2 diabetes. 73% versus 13% after 2 years. Dixon et al. Diabetic Medicine 2011

85 Impact on hypertension 95 patients with established hypertension undergoing RYGBP 72% female, Mean BMI 47 Mean excess body weight loss = 66% at 12 months Mean systolic BP fell from 140+/-17 to 120+/-18 Mean diastolic BP fell from 80+/-11 to 71+/-8 46% complete resolution (related to shorter duration of disease) Hinojosa. J Gastroint Surg 2009; 13: 793-7

86 Impact on lipids Retrospective study of 101 RYGBP patients using Framingham risk equation Systolic BP 143+/-20 to 123 +/-18 Diastolic BP 81+/-10 to 71 +/-11 Total cholesterol 202 to 165 LDL-C 118 to 97 HDL-C 45 to 51 Kligman et al. Surgery 2008; 143: 533-8

87 Impact on cardiac risk factors Framingham risk scores applied to calculate 10 year CV risk in 197 RYGBP patients and 163 controls Framingham 10 year risk score 7.0 to 3.5% in RYGBP patient 7.1 to 6.5% in controls Batsis et al. Am J Cardiol 2008; 102:

88 Impact on NAFLD 16 patients undergoing liver biopsies at RYGBP and subsequent incisional hernia repair Initial Biopsy Post-op biopsy % improved Steatosis 16 (100%) 15 (94%), resolved in 78% Inflammation 15 (94%) 12 (80%) Ballooning 14 (88%) 12 (86%) Perisinusoidal fibrosis 14 (88%) 6 (42%) Portal fibrosis 13 (82%) 6 (48%) Clark Obes Res 2005

89

90

91 Summary (1) Bariatric surgery is the fastest growing surgical speciality with good outcomes Cost effective within a year MDT approach now widespread Safe and effective but in some ways palliative Massive disparity between the need and the capacity Rationing and a utilitarian approach - who do we treat? the best or the worst Well regulated; national database Current UK wide trail GBP vs LB vs SG

92 Summary (2) Bariatric surgery is not magic Patients must commit to lifelong lifestyle changes Patients and healthcare professionals must accept what is and is not possible and balance risks with benefits