Multidisciplinary Clinic of Metabolic & Bariatric Surgery

Weight Reduction Procedures

Risk of Surgery

Who Need Surgery

Choice of Procedures

Metabolic Surgery

Life after Surgery

Metabolic Surgery

Surgical treatment of Type 2 diabetes – Metabolic Surgery

T2DM – An Asia Problem
Obesity and type 2 diabetes mellitus (T2DM) are an ongoing health-care problem worldwide. Both diseases are closed related and very difficult to be controlled by current medical treatment, including diet, drug therapy and behavioral modification. In Asia, T2DM is a more important epidemic health problems than obesity. It was estimated that T2DM affecting more than 150 million peoples worldwide and expected to be doubled by the year 2025. However, more than half of the patients are Asian, including 31.7 million diabetes patients in India and 20.8 million diabetes patients in China while only 17.7 million patients in the USA. Numerous studies have demonstrated the high levels of metabolic risk factors at relatively low levels of BMI among Asian population because of more prone to have central obesity. There is an urgent need for prevention and treatment of T2DM in this region.

Gastrointestinal Surgery & Diabetes
Gastrointestinal surgery, such as bariatric surgery, is the most powerful ammunition for obesity treatment. There are also strong evidences that bariatric surgeries can improve and even cure most of the associated T2DM in morbidly obese patients.
The mechanism for T2DM resolution after bariatric surgery is intriguing. On one hand, a, sustained weight reduction plays the key mechanism on long-term effect of resolution of T2DM. Weight & fat reduction significantly improve the insulin resistance in T2DM patient which improves the glucose control. However, change of physiology of gastrointestinal tract also plays an important role in DM improvement. Gastrointestinal surgery may affect gastric emptying rate, proximal gut absorption and distal small bowel transit time. Recent studies suggested that these change may alter the gut hormone release, such as ghrelin, GLP-1, GIP and PYY, which are important hormone involve in glucose control. Moreover, recent researches had also showed that modulation of gastrointestinal neuronal electric signal will also affect satiety and diabetes control.

What is Metabolic Surgery
The difference between bariatric surgery and metabolic surgery is subtle. Usually we define Metabolic Surgery as if the primary aim of surgery is for diabetes control / remission (including non-morbidly obese patients), while Bariatric Surgeries are primarily for weight reduction (include only morbidly obese patients). Although traditional bariatric surgery for morbidly obese patients (patient selection) with diabetes are well accepted treatment option, application of these surgeries to NON-MORBID OBESE (BMI < 30) and use of NEW PROCEDURE in diabetic patients should not be taken lightly. These procedures are still considered as EXPERIMENTIAL as there are still insufficient data regarding its safety and effectiveness, especially in long term. When patients are going to receive metabolic surgery, it should be conduct under a professional Institute Review Board (IRB) approved protocol with adequate explanation and follow up in order to protect both the patients and physician about the unknown effect and long-term sequels.

Consensus on Metabolic Surgery in Asia
In August 2008, fifty-two professionals involved in the field of bariatric surgery, metabolic surgery, diabetes and medical research from countries across Asia were met at India. A Consensus was drawn during the meeting and these recommendations are endorsed by the Asia-Pacific of Metabolic and Bariatric Surgery Society (APMBSS) and the Asia-Pacific Chapter of International Federation of Surgery of Obesity (IFSO) regarding the use of surgery as treatment of obesity and diabetes.

Recommendations

1)	Bariatric/Gastrointestinal Metabolic surgery should be considered as a treatment option for obesity in people with Asian ethnicity with a BMI more than 35 kg/m2 with or without co-morbidities.
2)	Bariatric/Gastrointestinal Metabolic surgery should be considered as a treatment option for obesity in people with Asian ethnicity above a BMI of 32 with co-morbidities.
3)	Bariatric/Gastrointestinal Metabolic surgery should be considered as a treatment option for obesity in people with Asian ethnicity above a BMI of 30 if they have central obesity (waist circumference more than 80 cm in females and more than 90 cm in males) along with at least two of the additional criteria for metabolic syndrome: raised triglycerides, reduced HDL cholesterol levels, high blood pressure and raised fasting plasma glucose levels.
4)	Any surgeries done on diabetic patients with a BMI less than 30 kg/ m2 should be strictly done only under study protocol with an informed consent from the patient. The nature of these surgeries should be considered as yet purely experimental.

Metabolic surgery – Possible options

1)	Traditional bariatric surgery Application of traditional restrictive surgery (e.g. adjustable gastric banding, sleeve gastrectomy) and malabsorptive procedure (gastric bypass, biliopancreatic diversion) will induce weight loss and hence improve diabetic control. The surgical risk and degree of DM improvement may be different between difference procedures, and patients should be well informing on the pros and cons of these procedures before surgery. Our center are currently conducting research on the application of surgery in moderate obese (BMI 25-30) patients with poor control diabetes.
2)	Electro-modulation Application of electric stimulation to stomach (e.g. Gastric Contraction Modulator, GCM) and vagus nerve (e.g. Neuro-Blocking) in achieving weigh reduction and diabetes improvement had been studied in the last few years. "Gastric Contraction Modulator" is an implantable device which generates electrical pulses to stimulate the stomach muscles. This device is introduced by laparoscopic technique and works like a pacemaker. It enhances the activity of gastric muscles during a meal, which activates and modifies the nervous and hormonal signals. The stimulation causes the subject to feel full sooner, reduce food intake and thus take less food, resulting in weight loss. This is often accompanied by improvement in blood glucose levels, blood pressure and waist circumference. Our center had started a clinical trial since 2010, which aims to compare traditional insulin therapy against the use of "Gastric Contraction Modulator" implant in difficult-to-treat obese T2D patients. Instead of starting insulin injection therapy, moderately obese patients (BMI 25-30) will receive laparoscopic implantation of this device at the Prince of Wales hospital.
3)	New Bariatric / Metabolic Surgical Procedures Apart from traditional bariatric surgery, there are some new innovative bariatric surgical procedures developed in the recent year which designed to induce metabolic change by manipulation of gastrointestinal anatomy. These procedures include pure duodeno-jejunal bypass (without gastric diversion), sleeve gastrectomy with duodeno-jejunal bypass, ileal interposition with or without sleeve gastrectomy and greater curvature plication. Although the initial results of these procedures are promising, there are still potential surgical risks among these surgeries. The application of these procedures in diabetic patients is still experimental and the long term safety and efficacy will await further evaluation.

手術治療二型糖尿病 - 代謝手術

二型糖尿病 : 一個亞洲的問題
肥胖與二型糖尿病是一個持續的全球衛生保健問題。這兩種疾病是密切相關，目前以內科治療方法包括飲食，藥物治療和行為改變，但問題乃是非常難以控制。在亞洲，二型糖尿病是一個比肥胖較流行和重要的健康問題。據估計，全球二型糖尿病的病患者預計將在2025年翻了一翻，影響超過1.5億人。然而，這些糖尿病患者超過一半是亞裔，其中包括印度有約3170萬，中國有約2080萬，只有1770萬患者在美國。許多研究已證實了在亞洲人在相對較低的BMI水平，更容易有代謝綜合症的危險因素。目前有迫切的需要在這一地區預防和治療二型糖尿病。

胃腸外科及糖尿病
胃腸手術，如減肥手術，是有效治療病態肥胖的方法。有證據顯示，減重手術可以改善，甚至治愈病態肥胖患者的二型糖尿病。
為什甚減肥手術能治愈二型糖尿病? 現時仍在研究及有爭議。一方面，其中一個關鍵的原因是減肥手術能持續減重。減少重量及脂肪能顯著地改善二型糖尿病病人胰島素抵抗，從而改善血糖控制。然而，改變胃腸道的生理及運作，對糖尿病也起著重要的影響。胃腸手術能影響胃排空，近端腸道吸收，及遠端小腸轉運時間。最近的研究顯示，這些變化能改變腸道釋放激素，如胃飢素(ghrelin)， GLP- 1，胃抑素 (GIP) 和酪酪肽 (PYY) 能影響血糖控制的重要激素。此外，最近的研究還顯示，調節胃腸道神經信號也會影響飽足感和控制糖尿病。

何謂代謝手術?
減肥手術和代謝手術有很微妙的關係和區別。通常如果手術是主要用於減肥（只包括病態肥胖患者），便稱之為減肥手術。但如果手術的主要目的是為控制/緩解糖尿病（包括非病態肥胖患者），我們便定義猶如代謝手術。雖然現時應用傳統減肥手術於患有糖尿病之病態肥胖患者（選擇標準），是以經廣為接受的治療選擇，但當應用這些手術於非病態肥胖的糖尿病患者（身體質量指數 BMI 少於30），或使用新的手術方法時，便不宜掉以輕心。因為這些治療程序仍在研皆段，被視為實驗性。由於尚未就其長期的安全和有效性有足夠的數據，當病人將接受代謝手術，應該根據有專業性的審查委員會（IRB）批准的方案進行，作出足夠的解釋和跟進，以保護病人和醫生就這類手術未知的結果及長期影響。

代謝手術在亞洲的共識
2008年8月，亞洲各國五十二個在減肥手術，代謝手術，治療糖尿病和醫學研究的醫生及專業人士，在印度舉行會議。會議期間，對這關於使用手術作為治療肥胖和糖尿病問題，達到一種共識，這些建議並得到亞太代謝與減重外科學會（APMBSS）和國際外科

在亞洲共識建議:

1)	對於身體質量指數 BMI 超過 35 kg/m2以上肥胖的人仕，無論有相關疾病與否，減重/腸道代謝手術應被視為治療的一種選擇。
2)	對於身體質量指數 BMI 超過32 kg/m2以上及患有肥胖相關疾病的人仕，減重/腸道代謝手術應被視為治療的一種選擇。
3)	對於身體質量指數 BMI 超過30 kg/m2以上，如果他們有中央型肥胖（男性腰圍超過 80厘米，女性超過 90厘米）以及至少兩個額外的代謝綜合症標準 (高甘油三酯水平，低高密度脂蛋白膽固醇水平，高血壓，高空腹血糖水平)，減重/腸道代謝手術應被視為治療的一種選擇。
4)	對於身體質量指數BMI低於30 kg/m2糖尿病患者做任何手術，只應在有病人的知情同意，及在與嚴格研究協議內進行。這些手術的性質，應被視為純實驗性質。

代謝手術 - 可能的選擇

1)	傳統的減肥手術應用傳統的限制性手術（如可調式胃束帶手術，袖狀胃切除）和吸收不良手術（胃繞道手術，膽胰分流術）會導致體重下降，從而改善糖尿病的控制。不同手術程序之間，在手術風險和改善糖尿病能力，可能有不同程度的差異，這些程序之利弊，在手術前應清楚告知病人。本中心目前正在進行研究，傳統的減肥手術在應用於中度肥胖（身體質量指數BMI 25-30）而其糖尿病控制不良的患者。
2)	脈衝電激調整治療在過去幾年就應用脈衝電激胃腸組織從而控制體重和改善糖尿病，進行了不少研究，如「胃動力調整器」(Gastric Contraction Modulator) 和「迷走神經堵塞器」(Vagus Nerve Blocker)。其中，「胃動力調整器」是一種先進的植入式儀器，在概念上有如心臟起搏器，透過腹腔鏡手術將儀器植入體內，利用脈衝電流刺激胃部肌肉。當病人進食時，透過脈衝電流增強胃部肌肉活動，從而激活特別的神經反應及激素分泌。這刺激能使病人很有吃飽的感覺，令食量減少。其結果是能改善血糖水平，伴隨著的是減輕體重，降低血壓和縮減腰圍。本中心自2010年以來的開始了臨床試驗，目的是探討及比較「脈衝胃動力調整器」與傳統胰島素治療的利弊。此項研究仍在進行之中，現希望糖尿病患者中，篩選及招募更多合適的中度肥胖糖尿病患者 (體重質量指標介符25至35 kg/m2 ) ，參加此項研究，接受植入「脈衝胃動力調整器」之腹腔鏡手術，從而與胰島素注射治療的效用作更深入及長久的比較，以探討「脈衝胃動力調整器」為治療血糖難控之二型糖尿病的新方法。
3)	新的減肥/代謝外科手術方法除了傳統的減肥手術，最近也發展一些創新的外科手術，旨在改變消化道解剖與操縱胃腸生理運行，促使改善代謝綜合症，治療糖尿病。這些程序包括純十二指腸空腸繞道（無胃改道），袖長胃切除術連十二指腸空腸繞道術，迴腸位置轉移術 (有或無袖狀胃切除)及胃大彎折疊術。儘管這些手術的初步結果是令人鼓舞的，其中依然存在潛在的風險。這些外科手術在應用糖尿病患者，仍處於試驗階段，其長期安全性和有效性將有待進一步的評估。