Persistent correlation of ghrelin plasma levels with body mass index both in stable weight conditions and during gastric-bypass-induced weight loss.

BACKGROUND: Studies done on serial changes in plasma ghrelin levels after gastric bypass (GBP) have yielded contrasting results since decreased, unchanged, or increased levels have been reported in the literature. This study investigates whether or not GBP has an inhibitory effect on fasting ghrelin levels independently of weight loss. METHODS: Fasting ghrelin levels were measured in 115 stable body weight females, classified as normal body weight (NW; body mass index (BMI)<25 kg/m2), overweight (OW; BMI 25-30 kg/m2), and obese subjects, divided in three subgroups with increasing BMI (BMI 30-40 kg/m2; BMI 40-50 kg/m2; BMI>50 kg/m2). RESULTS: Each obese subgroup showed significantly lower ghrelin levels as compared to both NW (p<0.0001) and OW subjects (p<0.05 or 0.005); however, no significant differences were observed within the three obese subgroups. Forty-nine obese patients underwent a GBP. Plasma ghrelin, measured at 3, 6, and 12 months after GBP, significantly increased from the sixth month on (p<0.0001). When patients were classified, at each postoperative time point, according to their actual BMI, ghrelin was significantly (p=0.0002) related to postoperative BMI and not significantly different from ghrelin measured in stable body weight conditions. CONCLUSIONS: Fasting ghrelin displays an inversely significant correlation with BMI in both stable body weight conditions and after GBP. No evidence was found that GBP had an effect on fasting ghrelin levels, independent of weight loss.

Vascular invasion in pancreatic cancer: evaluation of endoscopic ultrasonography, computed tomography, ultrasonography, and angiography.

PRINCIPLES: Current methods for detecting vascular invasion in pancreatic cancer can be inaccurate, invasive, and expensive. The aim of this study is to assess the value of current imaging modalities in determining vascular invasion by pancreatic cancer. METHODS: The results of Endoscopic Ultrasonography (EUS), Computed Tomography (CT), Ultrasonography (US), and Angiography performed in 170 patients, suffering from pancreatic cancer, were retrospectively studied and correlated with intra-operative findings and surgical anatomopathological diagnosis after resection. We assessed sensitivity, specificity, positive and negative predictive values, and accuracy for detecting vascular invasion. RESULTS: EUS turned out to be the most reliable imaging technique for detecting vascular invasion in pancreatic cancer, with a sensitivity of 55%, specificity of 90%, positive predictive value of 61.1%, negative predictive value of 87.5%, and accuracy of 82.2%. CT results were 39.4%, 90%, 52%, 84.4%, and 79.1% for the respective categories, with however, better results with multislice CT. The US results were 3.7% for the sensitivity, 96.3% for the specificity, 25% for the positive predictive value, 75.2% for the negative predictive value, and 73.4% for the accuracy. For angiography, the sensitivity, the specificity, the positive predictive value, the negative predictive value, and the accuracy were 52.6%, 72.3%, 43.5%, 79.1%, and 66.7% respectively. CONCLUSION: In this study, EUS was the most valuable imaging modality in assessing vascular invasion (especially for venous invasion) for pancreatic cancer, with an accuracy of more than 80%. A further prospective study should be carried out to evaluate the combination of imaging modalities for the detection of vascular involvement, especially with multi-slice CT which almost reached the performances obtained by EUS.

Preoperative work-up in asymptomatic patients undergoing Roux-en-Y gastric bypass: is endoscopy mandatory?

BACKGROUND: We aimed to determine before Roux-en-Y gastric bypass (RYGBP) in asymptomatic morbidly obese patients: 1) the prevalence of abnormal findings at upper gastrointestinal (UGI) endoscopy; 2) Helicobacter pylori (HP) status; 3) clinical consequences of these findings; and 4) associated costs. METHODS: We retrospectively reviewed 468 consecutive patients, excluded those with UGI symptoms, drug intake or previous UGI endoscopy/surgery, and analyzed findings in the 319 remaining patients (68%). RESULTS: There were abnormal findings in 147 patients (46%), including 54 hiatal hernias and 146 parietal (i.e. mucosal or submucosal) lesions. The most significant were 7 ulcers and 2 gastric polyposis. HP was detected (using CLO-test) in 124 patients (39%). Histopathological examination of biopsies was abnormal in 109/161 patients (68%), and disclosed mainly chronic gastritis (n=98). Abnormal findings were more frequent in HP-positive compared to HP-negative patients (94 vs 51%, P<0.001). Findings had clinical implications in only 4% of patients: delayed surgery (7 ulcers), prophylactic gastrectomy (2 gastric polyposis), unnecessary work-up (3 irrelevant/false-positive diagnoses), and inclusion in a screening program (1 Barrett's esophagus). Mean cost of complete UGI work-up was 389 euro/patient. CONCLUSION: Asymptomatic morbidly obese patients frequently harbour UGI lesions warranting UGI work-up before RYGBP. However, routine endoscopy presents drawbacks. We propose a less invasive strategy which reduces costs and limits false-positive results and the subsequent investigations that they require. In our series, it would have missed two gastric polyposis only, for which no formal recommendation has yet been issued. This strategy could be a valuable alternative to routine UGI endoscopy before RYGBP in asymptomatic patients.

[Surgical treatment of obesity in 2006]. / Chirurgie de l'obésité en 2006.

Roux-en-Y gastric bypass (RYGB), mostly since it is performed laparoscopically, is presently the technique of choice for the treatment of morbid obesity. In the United States, more than 80% of all bariatric procedures are RYGB, and our country follows the same way with more than 60% of RYGB in 2004. In Switzerland, this procedure can be considered for morbidly obese patients only (Body Mass Index > or = 40 kg/m2). RYGB is both strongly restrictive and lightly malabsorptive, and induces a 60% mean excess weight loss with a dramatic resolution of comorbidities. The mortality and morbidity of this operation are very low, particularly when compared to the death and disease risks associated with obesity. These patients should be treated by a specialized multidisciplinary team.

The effect of insulin on cardiac autonomic balance predicts weight reduction after gastric bypass.

AIMS/HYPOTHESIS: The aim of this study was to assess the predictive role of autonomic reactivity in body weight loss induced by gastric bypass. METHODS: A group of 22 morbidly obese subjects, who were due to undergo a gastric bypass, were submitted, before surgery, to a euglycaemic-hyperinsulinaemic clamp, during which a continuous recording of the ECG was performed. The effect of insulin on cardiac autonomic balance was evaluated by performing power spectral analysis of heart rate variability. The low-to-high frequency ratio was calculated before and during the clamp and its modifications were expressed as % delta low-to-high frequency ratio (%Delta L: H). RESULTS: Preoperative %Delta L: H showed a significant (p=0.0009, r2=0.43), positive relationship to the reduction of body weight, measured 1 year after surgery and expressed as % excess weight loss (% EWL). Preoperative BMI was also significantly (p=0.0009, r2=0.43) negatively related to the 12-month % EWL. In a multiple regression analysis, %Delta L: H remained a significant (p=0.003), independent predictor of body weight loss, even when preoperative BMI or age, % fat mass, insulinaemia and glucose disposal were taken into account. CONCLUSIONS/INTERPRETATION: The best correction of excess body weight was achieved by those obese subjects who had a preserved capacity to shift their cardiac autonomic balance towards a sympathetic prevalence in response to an euglycaemic-hyperinsulinaemic clamp. Further studies are needed to elucidate the mechanisms through which the autonomic nervous system influences weight reduction.

Relationship between sympathetic reactivity and body weight loss in morbidly obese subjects.

OBJECTIVE: To investigate the possible role of peripheral sympathetic activity in gastric bypass-induced body weight loss. SUBJECTS AND METHODS: In 42 morbidly obese patients (sex: 36 f/6 m; BMI: 46.0+/-0.7 kg/m(2)) undergoing a gastric bypass, the skin vasoconstrictor reflex in answer to a deep inspiration was measured by laser Doppler fluximetry. The extent of vasoconstriction, measured at the second finger of the left hand, was expressed as percent reduction of the basal blood flux (% vasoconstriction). Insulin sensitivity was assessed before surgery in a subset of patients (n=11), by the method of euglycemic, hyperinsulinemic clamp. Body weight and composition were evaluated before, and 3, 6 and 12 months after surgery. At the same time points, energy intake (kJ/day) was evaluated by means of both food record diary and alimentary anamnesis. RESULTS: The % vasoconstriction, which was significantly (P=0.01) greater in normoglycemic subjects than in diabetic ones, was also significantly (P=0.03) related to the extent of insulin sensitivity measured during the euglycemic clamp. The % vasoconstriction showed a significant (P>0.0001), positive correlation with weight reduction obtained between the 6th and 12th months following surgery; as a consequence, % vasoconstriction was significantly (P=0.0004) related to the overall body weight loss achieved during the year following the operation. These correlations remained significant in multiple regression analysis with adjustment for age, initial body weight, plasma glucose and insulin (P=0.0007 and 0.006, respectively). The % vasoconstriction was also significantly (P=0.0006), negatively related to energy intake measured 12 months after surgery. CONCLUSIONS: In conditions of stable body weight, the sympathetic nervous system (SNS) reactivity is influenced by the degree of insulin resistance. A high capacity to activate the SNS, measured before surgery, is associated with both a larger gastric bypass-induced weight loss and a lower energy intake, at the phase of weight stabilization.

Factors influencing energy intake and body weight loss after gastric bypass.

OBJECTIVE: The gastric bypass-induced quantitative and qualitative modifications of energy intake (En In, kcal/day) and their impact on body weight (bw) loss were evaluated. The factors influencing energy intake and body weight loss were also investigated. DESIGN: Longitudinal study. SETTING: University Hospital of Geneva. SUBJECTS: Fifty obese women undergoing a Roux-en-Y gastric bypass. RESULTS: The reduction of EnIn was significantly related to bw loss expressed either in kg or as percentage correction of excess bw (P<0.01 for both), whereas the post-operative modifications of diet composition did not play a role. Age and initial bw significantly influenced bw loss (P<0.0001 and P<0.001, respectively), as shown by multiple regression analysis. Patients were divided into four sub-groups according to their age (under or over 35 y) and initial bw (under or over 120 kg). ANOVA showed that under 35-y-old subjects reduced their EnIn significantly more than their older counterparts having similar bw (P<0.02 and P<0.05); consequently, bw loss, expressed in kg, was significantly (P<0.0001 and P<0.0005) larger in younger patients. Subjects with an initial bw over 120 kg lost significantly (P<0.001 and P<0.02) more weight as compared to patients with a smaller degree of obesity (under 120 kg) and similar age. CONCLUSIONS: Gastric bypass-induced body weight loss is mainly due to the reduction of EnIn, whereas the qualitative modifications of the diet do not play a role. Younger subjects have a greater capacity to reduce EnIn and, therefore, lose more weight. Pre-operative high degree of obesity leads to a larger weight reduction, probably because of a greater energy deficit.

Energy economy hampers body weight loss after gastric bypass.

The impact of energy economy on body weight loss was investigated in 20 obese women, submitted to Roux-en-Y gastric bypass. Resting energy expenditure (REE), substrate oxidation rates, plasma glucose, free fatty acid, and insulin and leptin levels were measured before and 3, 6, and 12 months after surgery. Predicted REE was obtained from linear regression analysis of REE and fat free mass, in a group of 85 women, whose body mass index ranged between 20 and 60 kg/m(2). The deviation from predicted REE, calculated as area under the curve (AUC) over the 12-month period for each patient, was considered as the expression of energy economy. Energy economy AUC was significantly (P: < 0.005) negatively related to the weight lost during 12 months after surgery. Energy intake, calculated from self-reported food consumption, was also expressed as AUC. Energy intake AUC showed a significant (P: < 0.002) positive correlation with weight loss. Lipid oxidation rate, also calculated as AUC, significantly correlated, negatively, with energy economy (P: < 0. 001) and, positively, with energy intake (P: < 0.002). Preoperative leptin values were significantly (P: < 0.01) linked to individual energy economy capacity. In conclusion, after Roux-en-Y gastric bypass, energy economy hampers the weight loss process, probably through a low fat oxidation rate.

[Ischemic risk in the case of celiac trunk occlusion in patients undergoing pancreatodeodenectomy. Multicenter study and review of literature]. / Le risque ischémique en cas d'obstruction du tronc coeliaque chez les patients devant subir une duodénopancréatectomie. Enquête multicentrique et revue de la littérature.

OBJECTIVES OF THE STUDY: To assess the risk of ischemia in patients undergoing pancreatoduodenectomy and presenting celiac trunk occlusion. METHODS: Multicenter survey and review of the literature. PATIENTS: We collected data from 22 patients (15 males and 7 females), with a median age of 66 years. Indication for pancreatic resection was adenocarcinoma of the head of pancreas (N = 9), other peri-ampullary tumors (N = 7) and chronic pancreatitis (N = 6). Trial clamping of the gastroduodenal artery was performed in 16 patients and was found to be positive in 9, who underwent a revascularization procedure. Among 6 patients who did not undergo trial clamping, 4 developed ischemia during pancreatic resection and unplanned revascularization had to be performed. Five patients developed complications (morbidity = 23%), which were fatal in 2 cases (mortality = 9%). Prevalence of celiac trunk occlusion has been estimated at 2-3% of all pancreatoduodenectomies. CONCLUSIONS: The risk of supra mesocolic ischemia by obstruction of the coeliac trunk is low, but can be minimized by performing trial clamping of the gastroduodenal artery. Revascularization should be performed if trial clamping induces a reduction of blood flow.

The role of revascularization in celiac occlusion and pancreatoduodenectomy.

BACKGROUND: Performance of pancreatoduodenectomy involves sacrifice of the gastroduodenal artery (GDA), which poses an ischemic threat to the liver, stomach, pancreas, and various anastomoses in patients with celiac trunk occlusion. METHODS: A survey was conducted in surgical centers with expertise in the field of pancreatic surgery. Detailed information was collected from 17 institutions worldwide. Fifteen patients with celiac trunk obstruction were identified. The indication for resection was periampullary tumor in 10 cases and chronic pancreatitis in 5. RESULTS: The cause of occlusion was atheromatous disease in 13 cases and arcuate ligament in 2. Trial clamping of the GDA was done in 11 patients, and provoked obvious ischemia in 4. Six patients underwent vascular procedures: the arcuate ligament was severed in 2 cases, the GDA was preserved in 2 cases of chronic pancreatitis, an aorto-hepatic bypass was performed in 1 case, and the celiac trunk was reimplanted in 1 case. Complications occurred in 5 patients, with 2 fatalities. CONCLUSIONS: Occlusion of the celiac trunk in patients undergoing pancreatoduodenectomy rarely leads to significant problems. Trial clamping of the GDA is required to assess the need for revascularization.

Protective subpleural blanketing of intrathoracic esogastric anastomosis after esophagectomy.

Esophagectomy followed by intrathoracic anastomosis is threatened by leakage which may prove all the more serious that mediastinal contamination is extensive. In the technique presented, the esogastric anastomosis is slipped under the upper mediastinal pleura which is kept intact, after the azygos vein has been ligated and divided. This pleural 'blanket' may act as an efficient barrier against potential digestive spillage into the mediastinum.

[Protection of intrathoracic anastomosis by pleural tent methods after Ivor-Lewis esophagectomy]. / Protection des anastomoses intrathoraciques par le procédé de la tente pleurale après oesophagectomies selon Ivor-Lewis.

PURPOSE OF THE STUDY: Description of a technical procedure to diminish the risk of spillage into the mediastinum in case of leakage from an intrathoracic anastomosis after partial esophagectomy. METHOD: In Ivor-Lewis procedures for cancer of the middle or lower third of the esophagus, the esogastric anastomosis is slipped under ther upper mediastinal pleura which is kept intact. From 1989 to 1997, this technique has been used in 43 consecutive patients (squamous carcinoma in 22, adenocarcinoma in 21). Three patients died postoperatively (7%) and complications (in 38%) were mostly pulmonary and cardiac. No anastomotic leak was detected on routine Gastrografin swallow performed on the 7th postoperative day. Three patients required dilation for stenosis. DISCUSSION AND CONCLUSION: Subpleural blanketing of intrathoracic anastomoses after esophagectomy is safe and easy to do, and should help diminish the consequences of possible anastomotic leakage.

[Cephalic duodenopancreatectomy with pylorus preservation: for which patients?]. / Duodénopancréatectomie céphalique avec conservation du pylore: pour quels patients?

From 1984 to the end of 1993, we performed 51 duodenopancreatectomies with pylorus preservation (27 for chronic pancreatitis and 24 for tumours). We have a complete follow up for 96% of our patients with a mean range of 76 months in the first group and 33 months in the second. There was no per- or postoperative mortality and 15% immediate postoperative morbidity. We observed 5 cases (10%) of anastomotic ulceration. New surgical technics enabled us to avoid this major complication for our last 31 patients. The short and long term benefits of pylorus-preserving duodenopancreatectomy on patients' wellbeing, nutritional status and weight gain were confirmed in 22 patients (82%) with pancreatitis. The mean survival time in patients with tumors (periampullary and head of pancreas adenocarcinoma) is similar to that with the classical Whipple procedure.