The human brain stands out among mammals by being unusually large. The expensive-tissue hypothesis explains its evolution by proposing a trade-off between the size of the brain and that of the digestive tract, which is smaller than expected for a primate of our body size. Although this hypothesis is widely accepted, empirical support so far has been equivocal. Here we test it in a sample of 100 mammalian species, including 23 primates, by analysing brain size and organ mass data. We found that, controlling for fat-free body mass, brain size is not negatively correlated with the mass of the digestive tract or any other expensive organ, thus refuting the expensive-tissue hypothesis. Nonetheless, consistent with the existence of energy trade-offs with brain size, we find that the size of brains and adipose depots are negatively correlated in mammals, indicating that encephalization and fat storage are compensatory strategies to buffer against starvation. However, these two strategies can be combined if fat storage does not unduly hamper locomotor efficiency. We propose that human encephalization was made possible by a combination of stabilization of energy inputs and a redirection of energy from locomotion, growth and reproduction.

Energetics and the evolution of human brain size

Deficiencies in micronutrients after bariatric operations are frequent, despite routine supplementation. Main outcome measures were pre- and postoperative frequency of nutrient deficiencies and success rate of their treatment. Between 5/2004 and 12/2006, 136 patients (m:f = 0:4) with an average body mass index of 45 (35–58) kg/m2 and age of 53 (21–66) years were prospectively analysed. Laparoscopic Roux-Y-gastric bypass (LRYGB) was performed in 86 patients and laparoscopic sleeve gastrectomy (LSG) was performed in 50 patients. The patients were examined before surgery as well as 3, 6, 12, 24, 30, and 36 months postoperatively using a standard protocol including laboratory tests. The mean follow-up time was 24.4 (12–40) months; the follow-up rate was 100%. Prior to surgery, 57% of the patients had at least one deficiency, 23% of whom had vitamin D3 deficiency. Frequent postoperative deficiencies after LSG were zinc, vitamin D3, folic acid, iron, and vitamin B12; after LRYGB, vitamin B12, vitamin D3, zinc, and secondary hyperparathyroidism. No vitamin B1 or B6 deficiencies were found. Calcium levels were normal in all patients. Treatment of the deficiencies was mostly successful. Preoperatively, 57% of morbidly obese patients already had a deficiency. Postoperatively, significantly more vitamin B12 and vitamin D deficiencies and hyperparathyroidism were found in patients who had undergone LRYGB. After LSG, folate deficiency was more frequent (but not significantly so). Calcium levels were normal in all patients; therefore, parathyroid hormone and vitamin D3 levels are more sensitive markers for early detection of disorders of calcium metabolism. Iron deficiency anaemia is most efficiently treated by IV therapy.

Fewer Nutrient Deficiencies After Laparoscopic Sleeve Gastrectomy (LSG) than After Laparoscopic Roux-Y-Gastric Bypass (LRYGB)—a Prospective Study

Sleeve gastrectomy is a rapid and less traumatic operation, which thus far is showing good resolution of comorbidities and good weight loss if a narrower channel is constructed than for the duodenal switch There are potential intraoperative complications, which must be recognized and treated promptly Like other bariatric operations, there are variations in the technique used The laparoscopic sleeve gastrectomy (LSG) is being performed for superobese and high-risk patients, but its indications have been increasing A second-stage bariatric operation may be performed if necessary, with increased safety Long-term results of LSG and further networking are anxiously awaited

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The First International Consensus Summit for Sleeve Gastrectomy (SG), New York City, October 25–27, 2007

https://www.soard.org/article/S1550-7289(11)00597-1/pdf

Third International Summit: current status of sleeve gastrectomy

Sleeve gastrectomy (SG) has been accepted as an option for surgical treatment for obesity. This operation could be associated with motor gastric dysfunction and abnormal gastric emptying. The purpose of this prospective study is to present the results of gastric emptying to liquids and solids using scintigraphy in patients who underwent SG compared to normal subjects. Twenty obese patients were submitted to laparoscopic SG and were compared to 18 normal subjects. Gastric emptying of liquids and solids was measured by scintigraphic technique. Results were expressed as half time of gastric emptying and the percentage of retention at 20, 30, and 60 min for liquids and at 60, 90, and 120 min for solids. In the group of operated patients, 70% of them (n = 14) presented accelerated emptying for liquids and 75% (n = 15) for solids compared to 22.2% and 27.7%, respectively, in the control group. The half time of gastric emptying (T
1/2) in patients submitted to SG both for liquids and solids were significantly more accelerated compared to the control group (34.9 ± 24.6 vs 13.6 ± 11.9 min for liquids and 78 ± 15.01 vs 38.3 ± 18.77 min for solids; p < 0.01). The gastric emptying for liquids expressed as the percentage of retention at 20, 30, and 60 min was 30.0 ± 0.25%, 15.4 ± 0.18%, and 5.7 ± 0.10%, respectively, in operated patients, significantly less than the control subjects (p < 0.001). For solids, the percentage of retention at 60, 90, and 120 min was 56 ± 28%, 34 ± 22%, and 12 ± 8%, respectively, for controls, while it was 25.3 ± 0.20%, 9 ± 0.12%, and 3 ± 0.05%, respectively, in operated patients (p < 001). Gastric emptying after SG is accelerated either for liquids as well as for solids in the majority of patients. These results could be taken in consideration for the dietary indications after surgery and could play a significant role in the definitive results during the late follow-up.

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Scintigraphic Evaluation of Gastric Emptying in Obese Patients Submitted to Sleeve Gastrectomy Compared to Normal Subjects

Objective:To present 5-year results of sleeve gastrectomy (SG) with transit bipartition (TB) as a metabolic intervention for obesity.Background:Recent data suggest that high glycemic index foods may lead to a hormonally hyperactive proximal gut and a hypoactivate distal gut, which are linked to meta

Sleeve gastrectomy with transit bipartition: a potent intervention for metabolic syndrome and obesity.

Background
Recent physiological knowledge allows the design of bariatric procedures that aim at neuroendocrine changes instead of at restriction and malabsorption. Digestive adaptation is a surgical technique for obesity based in this rationale.

Enterohormonal Changes After Digestive Adaptation: Five-Year Results of a Surgical Proposal to Treat Obesity and Associated Diseases

Background: Mechanical obstacles to food ingestion, nutrient-excluded segments and malabsorption are common strategies of bariatric surgery which are a potential cause of symptoms or complications. We describe an operation "Digestive Adaptation with Intestinal Reserve" (DAIR) that does not utilize these tools, aiming fundamentally at neuroendocrine changes. Methods: The operation includes sleeve gastrectomy, omentectomy and enterectomy, maintaining the initial 40 cm of jejunum and final 260 cm of ileum (keeping the bowel length at the lower limit for adaptation to normal). Jejunum is laterally anastomosed to ileum 80 cm proximal to the cecum. A gastroileostomy creates a transit bipartition (ileum and proximal bowel in transit). 55 patients are presented whose follow-up is >12 months (12-34 months). Fasting ghrelin and resistin, and postprandial GLP-1 and PYY were measured. Results: Mean BMI reduction was 4.8, 9.5, 15.4 and 20.1 kg/m2 respectively at 1, 3, 6 and 12 months. Patients have early satiety and major improvement in pre-surgical co-morbidities, especially diabetes and hypertension. GLP-1 and PYY response to food ingestion were enhanced; fasting ghrelin and resistin were significantly reduced (P<0.05). Radiographic studies show nutrient transit through the pylorus and through the gastroileostomy. Early surgical complications (2 in 55 patients) resolved without sequelae. There were no signals of malabsorption, no deaths, and most patients present no symptoms at all. Conclusions: DAIR amplifies postprandial neuroendocrine response and provokes intense weight loss. DAIR reduces production of ghrelin and resistin and enables more nutrients to be absorbed distally enhancing GLP-1 and PYY secretion. Diabetes improved significantly without duodenal exclusion.

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Digestive Adaptation with Intestinal Reserve: a neuroendocrine-based operation for morbid obesity.

CONTEXT AND OBJECTIVE: Most bariatric surgical techniques include essentially non-physiological features like narrowing anastomoses or bands, or digestive segment exclusion, especially the duodenum. This potentially causes symptoms or complications. The aim here was to report on the preliminary results from a new surgical technique for treating morbid obesity that takes a physiological and evolutionary approach. DESIGN AND SETTING: Case series description, in Hospital Israelita Albert Einstein and Hospital da Policia Militar, Sao Paulo, and Hospital Vicentino, Ponta Grossa, Parana. METHODS: The technique included vertical (sleeve) gastrectomy, omentectomy and enterectomy that retained three meters of small bowel (initial jejunum and most of the ileum), i.e. the lower limit for normal adults. The operations on 100 patients are described. RESULTS: The mean follow-up was nine months (range: one to 29 months). The mean reductions in body mass index were 4.3, 6.1, 8.1, 10.1 and 10.7 kg/m2, respectively at 1, 2, 4, 6 and 12 months. All patients reported early satiety. There was major improvement in comorbidities, especially diabetes. Operative complications occurred in 7% of patients, all of them resolved without sequelae. There was no mortality. CONCLUSIONS: This procedure creates a proportionally reduced gastrointestinal tract, leaving its basic functions unharmed and producing adaptation of the gastric chamber size to hypercaloric diet. It removes the sources of ghrelin, plasminogen activator inhibitor-1 (PAI-1) and resistin production and leads more nutrients to the distal bowel, with desirable metabolic consequences. Patients do not need nutritional support or drug medication. The procedure is straightforward and safe.

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Preliminary results from digestive adaptation: a new surgical proposal for treating obesity, based on physiology and evolution

Objective Sleeve gastrectomy is the fastest growing surgical procedure to treat obesity in the world but it may cause or worsen gastroesophageal reflux disease. This article originally aimed to describe the addition of anti-reflux procedures (removal of periesophageal fats pads, hiatoplasty, a small plication and fixation of the gastric remnant in position) to the usual sleeve gastrectomy and to report early and late results. Methods Eighty-eight obese patients that also presented symptoms of gastroesophageal reflux disease were submitted to sleeve gastrectomy with anti-reflux procedures. Fifty of them were also submitted to a transit bipartition. The weight loss of these patients was compared to consecutive 360 patients previously submitted to the usual sleeve gastrectomy and to 1,140 submitted to sleeve gastrectomy + transit bipartition. Gastroesophageal reflux disease symptoms were specifically inquired in all anti-reflux sleeve gastrectomy patients and compared to the results of the same questionnaire applied to 50 sleeve gastrectomy patients and 60 sleeve gastrectomy + transit bipartition patients that also presented preoperative symptoms of gastroesophageal reflux disease. Results In terms of weight loss, excess of body mass index loss percentage after anti-reflux sleeve gastrectomy is not inferior to the usual sleeve gastrectomy and anti-reflux sleeve gastrectomy + transit bipartition is not inferior to sleeve gastrectomy + transit bipartition. Anti-reflux sleeve gastrectomy did not add morbidity but significantly diminished gastroesophageal reflux disease symptoms and the use of proton pump inhibitors to treat this condition. Conclusion The addition of anti-reflux procedures, such as hiatoplasty and cardioplication, to the usual sleeve gastrectomy did not add morbidity neither worsened the weight loss but significantly reduced the occurrence of gastroesophageal reflux disease symptoms as well as the use of proton pump inhibitors.

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Carlos Eduardo Malzoni

Papers

Sleeve gastrectomy with transit bipartition: a potent intervention for metabolic syndrome and obesity.

Enterohormonal Changes After Digestive Adaptation: Five-Year Results of a Surgical Proposal to Treat Obesity and Associated Diseases

Digestive Adaptation with Intestinal Reserve: a neuroendocrine-based operation for morbid obesity.

Preliminary results from digestive adaptation: a new surgical proposal for treating obesity, based on physiology and evolution

Sleeve gastrectomy with anti-reflux procedures