Gastric bypass procedures

Surgical therapy to help the severely overweight has been performed for the past 40 years. As with every therapeutic modality, there have been changes, refinements and improvement as this therapy has evolved. Although the basic concept of gastric bypass remains intact, numerous variations are being performed at this time. Recent data compiled by the International Bariatric Surgery Registry have demonstrated that surgeons are moving from simple gastroplasty procedures, favouring the more complex gastric bypass procedures as the surgical treatment of choice for the morbidly obese patient. This review will discuss the evolution of the gastric bypass procedures, and the reasons for and results of the changes. Gastric bypass may represent the best surgical approach for the treatment of morbid obesity.     

Gastric bypass with biliopancreatic diversion

Gastric bypass with biliopancreatic diversion (GBBPD) is a combined restrictive and malabsorptive procedure for the treatment of morbid obesity.     

Gastric emptying after gastric bypass

Gastric emptying of two test meals, consisting of ground beef and water and ground beef with 25 percent dextrose was measured with a scintigraphic technique in patients after gastric bypass surgery and in control subjects. Solid emptying was slower and liquid emptying was more rapid after gastric bypass and 25 percent dextrose emptied as rapidly as water. The pattern of gastric emptying after gastric bypass would favour more rapid initial absorption with liquid calories and may also be implicated in the dumping syndromes sometimes seen after gastric bypass.     

Gastric bypass and glucose metabolism

Roux-en-Y gastric bypass leads to a marked improvement of glucose control. The mechanisms are only partly known. Gastrointestinal hormones may play a role. Of these, glucagon-like peptide 1 and peptide YY have been most consistently associated with the beneficial effects of gastric bypass on glucose metabolism and weight. In this paper, a short review of the topic is presented and a suggestion of the improvement of glucose metabolism is made based on the current published work.     

Gastric emptying rate after gastric bypass and gastroplasty

Fifty-seven morbidly obese patients were randomized into two surgical treatment groups, gastric bypass (n = 29) and gastroplasty (n = 28). Studies of the gastric emptying with radionuclide-labelled food were performed preoperatively (12 patients) and postoperatively at 2 months (28 patients) and 12 months (49 patients). Pouch emptying after gastric bypass was slower at 2 months than at 12 months. After gastroplasty the emptying rate was the same at 2 and 12 months and the same as that of gastric bypass at 12 months. A statistically significant correlation between stoma diameter and emptying rate was seen 1 year after gastroplasty but not after gastric bypass. No correlation between emptying rate and weight loss was shown in either group. Differences in the mechanisms of action between these two methods are apparent and are discussed.     

胃旁路术减肥同时改善糖代谢的机制

胃旁路术在平稳减肥的同时能增加胰岛素敏感性,改善糖代谢紊乱。其机制包括胃减容以减少摄入,前肠旁路致胃肠-胰岛轴改变引起多种胃肠激素如ghrelin、胰升糖素样肽-1（GLP-1）、葡萄糖依赖性促胰岛素多肽、多肽YY等变化改善了胰岛素的分泌和（或）活性,脂肪细胞因子的改变如脂联素水平升高、瘦素及酰化刺激蛋白降低和一些炎性反应因子如C反应蛋白、白细胞介素-6（IL-6）的变化等。     

胃旁路术与胆胰转流术治疗2型糖尿病机制的研究

目的 比较胃旁路术(GBP)与胆胰转流术(BPD)对非胰岛素依赖性糖尿病大鼠的治疗效果,探讨其机制.方法 40只糖尿病GK大鼠按数字表法随机分为GBP组、BPD组、饮食控制组和对照组,每组10只.GBP组、BPD组分别行GBP及BPD手术;饮食控制组大鼠每天给予基础饲料15 g,自由进水;对照组不限食量.记录手术时间、死亡率.每周测空腹体重.检测治疗前及治疗后1、2、3、4、8、16周的空腹血糖、瘦素、胰岛素样生长因子-1(IGF-1)水平.结果 GBP组平均手术时间为(25±4)min,BPD组为(35±6)min;GBP组大鼠死亡1只,BPD组死亡3只,两组差异均有统计学意义(P值均＜0.01).治疗前各组大鼠血糖、瘦素及IGF-1水平无统计学差异.治疗后对照组大鼠血糖及瘦素均无明显变化.饮食控制组大鼠治疗后2周起血糖及瘦素水平开始下降,第4周时显著降低,并持续至16周(P＜0.05),但血IGF-1水平无明显变化.GBP组与BPD组大鼠治疗后2周起血糖及瘦素水平开始下降,而血IGF-1水平开始升高,并持续至16周[血糖:(6.8±1.0)、(6.3±0.8)mmol/L比(13.9±2.6)、(14.1±2.4)mmol/L;瘦素:(16.1±3.3)、(17.2±3.2)pg/ml比(29.4±3.9)、(29.4±3.9) pg/ml;IGF-1:( 166.1±8.3)、(142.2±8.2) ng/L比(119.4±8.8)、(109.8±7.9)ng/L,P值均＜0.01],但这两组的血糖及瘦素水平无统计学差异;而GBP组大鼠血IGF-1水平较BPD组升高更显著(P＜0.05).结论 GBP和BPD均能较好地控制糖尿病大鼠的血糖水平,其机制可能与瘦素的降低及IGF-1的升高有关.GBP在手术时间、死亡率及增加血IGF-1水平等方面优于BPD.     

胃旁路术治疗2型糖尿病的研究进展

全球糖尿病的发病率逐年上升,现有的规范化内科治疗仍不能完全阻止其病情进展及其并发症的发生,其治疗已成为世界性的难题.减重手术治疗2型糖尿病已在临床使用多年,其中应用最广泛的是胃旁路术,它可引起持久的体重减轻、缓解肥胖相关并发症,尤其是2型糖尿病.然而其治疗机制、适用人群、术后部分患者糖尿病复发的机制尚不明确,有待进一步研究阐明.     

Gastric cancer after gastric bypass for obesity. Case report.

We describe a patient in whom gastric cancer developed after gastric bypass for morbid obesity. In addition, we review the literature to emphasize the technical problems involved in diagnosing disease in the excluded portion of the stomach.     

Gastric bypass and resolution of proteinuria in an obese diabetic patient.

There is few human studies evidence that suggest a role for obesity in the formation and progression of glomerular lesions. We report the case of a morbidly obese female with diabetic nephropathy that was subsequently diagnosed with renal failure. Proteinuria resolved after gastric bypass procedure. The reduction of glomerular hyperfiltration and blood pressure associated with the important weight loss may be the major contributors to the decrease of proteinuria and serum creatinine levels in our patient.     

Gastric bypass alters the dynamics and metabolic effects of insulin and proinsulin secretion.

AIMS: Hyperproinsulinaemia is associated with obesity and is a risk factor for Type 2 diabetes. We explored the dynamics of proinsulin and insulin and postprandial effects on glucose and lipids in subjects who had undergone gastric bypass (GBP) surgery compared with morbidly obese (MO) subjects and normal weight control subjects (NW). METHODS: Subjects free from diabetes were recruited: 10 previously MO subjects [body mass index (BMI) +/- sd, 34.8 +/- 6.2 kg/m2] who had undergone GBP surgery, 10 MO subjects (BMI 44 +/- 3.1 kg/m2) and 12 NW control subjects (BMI 23.2 +/- 2.4 kg/m2). After an overnight fast, a standard meal (2400 kJ) was ingested and glucose, proinsulin, insulin free fatty acids and triglycerides were determined up to 180 min. RESULTS: Fasting proinsulin was similar in the GBP group and NW control subjects, but threefold increased in MO subjects (P < 0.05). Postprandial AUC for glucose was similar in the three groups and AUC for proinsulin was high in MO, intermediate in the GBP group and lowest in NW control subjects (P for trend = 0.020). Postprandial proinsulin at 60 min was similar in the GBP group and MO subjects and twofold higher than in NW control subjects. Postprandial proinsulin at 180 min was normal in the GBP group, but fivefold increased in MO subjects (P = 0.008). Insulin increased rapidly at 30 min in the GBP group and was normal at 90 min, whereas insulin was still increased at 90-180 min in the MO subjects (P < 0.001). CONCLUSIONS: MO subjects, free from diabetes, have elevated proinsulin concentrations in the fasting as well as the postprandial phase. After GBP surgery markedly lower fasting and postprandial proinsulin concentrations were observed, although BMI was higher compared with NW control subjects.     

胃旁路术对GK大鼠糖代谢影响及其与Ghrelin的关系

目的:观察胃旁路术(gastric bypass,GBP)对非肥胖型2型糖尿病大鼠(Goto-Kakizaki rats;GK大鼠)血糖的影响,并探讨其机制.方法:GK大鼠20只,Wistar大鼠10只,均为雄性.分为GK手术组、GK假手术组和Wistar假手术组,每组10只.手术组行胃旁路术.测定术前1wk及术后第1、2、4、8、12wk各组大鼠的空腹血糖(FPG)、糖化血红蛋白(HbAlc)和血清胰岛素(INS),并同期检测血清Ghrelin水平.结果:术后第12周,GK手术组大鼠FPG和HbAlc分别由术前的11.36mmol/L±1.14mmol/L和8.91%±0.36%下降到8.36±0.62mmol/L和6.35%±0.46%,血清INS由术前32.76mIU/L±2.37mIU/L上升到55.14mIU/L±5.45mIU/L,而Ghrelin由术前928.53ng/L±58.66ng/L下降到367.83ng/L±27.78ng/L,差异均有统计学意义(P<0.05).结论:GBP可以明显改善GK大鼠的糖代谢,其作用机制可能与降低Ghrelin水平,进而促进胰岛素分泌有关.     

Gastric bypass Roux-en-Y gastrojejunostomy--conversion to distal gastrojejunoileostomy for weight loss failure--experience in 41 patients

BACKGROUND: Surgery is the only effective treatment for morbid obesity. Gastric bypass could fail in up to 10% of the patients (excess weight loss under 50%). AIMS: To evaluate the weight loss determined by reoperation performing disabsortive variation of gastric bypass. PATIENTS AND METHODS: The records of 41 patients, in whom 32 were submitted to reoperation by one of three surgical techniques (Fobi, Brolin, distal gastrojejunoileal bypass) which consisted in increasing the disabsortive length of intestinal limb. RESULTS: The patients submitted to distal gastrojejunoileal bypass showed the best results (69.7%). CONCLUSION: The distal gastric bypass as a revisional procedure could be done in selected cases with the aim to improve the weight loss. It is advisable to refer these patients to selected centers (known as center of excellence) with experience in this area of bariatric surgery, in order to perform a very close follow-up.     

Gastric bypass surgery improves metabolic and hepatic abnormalities associated with nonalcoholic fatty liver disease

BACKGROUND & AIMS: Most patients with extreme obesity have nonalcoholic fatty liver disease (NAFLD). Although gastric bypass (GBP) surgery is the most common bariatric operation performed in obese patients in the United States, the effect of GBP surgery-induced weight loss on the metabolic and hepatic abnormalities associated with NAFLD are not clear. METHODS: Whole-body glucose, fatty acid and lipoprotein kinetics, liver histology, and hepatic cellular factors involved in inflammation and fibrogenesis were evaluated in 7 extremely obese subjects (body mass index, 58 +/- 4 kg/m(2)) before and 1 year after GBP surgery. RESULTS: At 1 year after surgery, subjects lost 29% +/- 5% of initial body weight (P < .01); palmitate rate of appearance in plasma, an index of adipose tissue lipolysis, decreased by 47% +/- 4% (P < .01); endogenous glucose production rate decreased by 27% +/- 7% (P < .01); and very-low-density lipoprotein-triglyceride secretion rate decreased by 44% +/- 9% (P < .05). In addition, GBP surgery-induced weight loss decreased hepatic steatosis but did not change standard histologic assessments of inflammation and fibrosis. However, there was a marked decrease in hepatic factors involved in regulating fibrogenesis (collagen-alpha1(I), transforming growth factor-beta1, alpha-smooth muscle actin, and tissue inhibitor of metalloproteinase 1 expression and alpha-smooth muscle actin content) and inflammation (macrophage chemoattractant protein 1 and interleukin 8 expression) (P < .05, compared with values before weight loss). CONCLUSIONS: These data demonstrate that weight loss induced by GBP surgery normalizes the metabolic abnormalities involved in the pathogenesis and pathophysiology of NAFLD and decreases the hepatic expression of factors involved in the progression of liver inflammation and fibrosis.