Jan Willem M. Greve

Preoperative biliary drainage for cancer of the head of the pancreas

BACKGROUND The benefits of preoperative biliary drainage, which was introduced to improve the postoperative outcome in patients with obstructive jaundice caused by a tumor of the pancreatic head, are unclear. METHODS In this multicenter, randomized trial, we compared preoperative biliary drainage with surgery alone for patients with cancer of the pancreatic head. Patients with obstructive jaundice and a bilirubin level of 40 to 250 micromol per liter (2.3 to 14.6 mg per deciliter) were randomly assigned to undergo either preoperative biliary drainage for 4 to 6 weeks, followed by surgery, or surgery alone within 1 week after diagnosis. Preoperative biliary drainage was attempted primarily with the placement of an endoprosthesis by means of endoscopic retrograde cholangiopancreatography. The primary outcome was the rate of serious complications within 120 days after randomization. RESULTS We enrolled 202 patients; 96 were assigned to undergo early surgery and 106 to undergo preoperative biliary drainage; 6 patients were excluded from the analysis. The rates of serious complications were 39% (37 patients) in the early-surgery group and 74% (75 patients) in the biliary-drainage group (relative risk in the early-surgery group, 0.54; 95% confidence interval [CI], 0.41 to 0.71; P<0.001). Preoperative biliary drainage was successful in 96 patients (94%) after one or more attempts, with complications in 47 patients (46%). Surgery-related complications occurred in 35 patients (37%) in the early-surgery group and in 48 patients (47%) in the biliary-drainage group (relative risk, 0.79; 95% CI, 0.57 to 1.11; P=0.14). Mortality and the length of hospital stay did not differ significantly between the two groups. CONCLUSIONS Routine preoperative biliary drainage in patients undergoing surgery for cancer of the pancreatic head increases the rate of complications. (Current Controlled Trials number, ISRCTN31939699.)

Lipopolysaccharide (LPS)-Binding Protein Mediates LPS Detoxification by Chylomicrons

Chylomicrons have been shown to protect against endotoxin-induced lethality. LPS-binding protein (LBP) is involved in the inactivation of bacterial toxin by lipoproteins. The current study examined the interaction among LBP, chylomicrons, and bacterial toxin. LBP was demonstrated to associate with chylomicrons and enhance the amount of LPS binding to chylomicrons in a dose-dependent fashion. In addition, LBP accelerated LPS binding to chylomicrons. This LBP-induced interaction of LPS with chylomicrons prevented endotoxin toxicity, as demonstrated by reduced cytokine secretion by PBMC. When postprandial circulating concentrations of chylomicrons were compared with circulating levels of low density lipoprotein, very low density lipoprotein, and high density lipoprotein, chylomicrons exceeded the other lipoproteins in LPS-inactivating capacity. Furthermore, highly purified lipoteichoic acid, an immunostimulatory component of Gram-positive bacteria, was detoxified by incubation with LBP and chylomicrons. In conclusion, our results indicate that LBP associates with chylomicrons and enables chylomicrons to rapidly bind bacterial toxin, thereby preventing cell activation. Besides a role in the detoxification of bacterial toxin present in the circulation, we believe that LBP-chylomicron complexes may be part of a local defense mechanism of the intestine against translocated bacterial toxin.

Human intestinal microbiota composition is associated with local and systemic inflammation in obesity

Intestinal microbiota have been suggested to contribute to the development of obesity, but the mechanism remains elusive. The relationship between microbiota composition, intestinal permeability, and inflammation in nonobese and obese subjects was investigated.

Revisional Surgery After Failed Vertical Banded Gastroplasty: Restoration of Vertical Banded Gastroplasty or Conversion to Gastric Bypass

Background: An increasing number of patients with a failed primary bariatric procedure present themselves for secondary treatment. Only a few studies have investigated critically the success of revisional surgery. In the present study, the effectiveness of revisional surgery for failed vertical banded gastroplasty (VBG) is analyzed: restoration of the VBG (reVBG) is compared to conversion to a Roux-en-Y gastric bypass (RYGB). Patients and Methods: From 1980 to 1996, 136 consecutive morbidly obese patients underwent primary RYGB (n = 20) or VBG (n = 16). Weight loss, indications and complications after revisional surgery were registered. The rate of revisional surgery after primary and secondary bariatric procedures was estimated by means of a Kaplan-Meier analysis. Results: Kaplan-Meier analysis revealed that 56% of the patients will eventually require revisional surgery after initial VBG over a 12-year period compared to 12% after initial RYGB (P < 0.01). After reVBG 68% will need revisional surgery over a 5-year period, while no further revisional surgery was required after conversion to a RYGB (P < 0.05). Body mass index dropped significantly after reVBG or conversion to RYGB for insufficient weight loss (P < 0.05), however, more revisional surgery was necessary after reVBG to achieve this result. The complication rate was comparable between reVBG and conversion to RYGB (33%). Conclusion: Conversion of a failed VBG to a RYGB is more effective than a reVBG, because conversion to RYGB provides satisfactory weight loss without requiring further revisional surgery.

Neutrophil Activation in Morbid Obesity, Chronic Activation of Acute Inflammation

Recent studies show that morbid obesity is associated with activation of the innate immune response. Neutrophil activation is a fundamental process in the innate immune response. Therefore, the activation state of neutrophils in severely obese subjects and the effect of bariatric surgery on neutrophil activation was evaluated. Neutrophil activation was assessed by measuring circulating concentrations of myeloperoxidase (MPO) and calprotectin in 37 severely obese and 9 control subjects (enzyme‐linked immunosorbent assay). Moreover, membrane expression of CD66b on circulating neutrophils was measured using flow cytometry in a group of seven severely obese and six control subjects. Immunohistochemical detection of MPO was performed in adipose and muscle tissue. Plasma MPO and calprotectin levels were significantly increased in severely obese subjects as compared to healthy controls, 27.1 ± 10.8 vs. 17.3 ± 5.5 ng/ml (P < 0.001) and 115.5 ± 43.5 vs. 65.1 ± 23.1 ng/ml (P < 0.001) for MPO and calprotectin, respectively. In line, CD66b expression was significantly increased in severely obese individuals, 177.3 ± 43.7 vs. 129.7 ± 9.2 (mean fluorescence intensity) (P < 0.01). Bariatric surgery resulted in decreased calprotectin, but MPO plasma levels remained elevated. Adipose and muscle tissue did not contain increased numbers of MPO expressing cells in severely obese individuals. These results point out that circulating neutrophils are activated to a greater extent in severely obese subjects. Our data support the finding that the innate immune system is activated in severely obese individuals. Moreover, because neutrophils have a short life span, this indicates that the chronic inflammatory condition associated with morbid obesity is characterized by a continuous activation of the innate immune system.

Meta-analysis of hemodynamic optimization: relationship to methodological quality

IntroductionTo review systematically the effect of interventions aimed at hemodynamic optimization and to relate this to the quality of individual published trials.MethodsA systematic, computerized bibliographic search of published studies and citation reviews of relevant studies was performed. All randomized clinical trials in which adult patients were included in a trial deliberately aiming at an optimized or maximized hemodynamic condition of the patients (with oxygen delivery, cardiac index, oxygen consumption, mixed venous oxygen saturation and/or stroke volume as end-points) were selected. A total of 30 studies were selected for independent review. Two reviewers extracted data on population, intervention, outcome and methodological quality. Agreement between reviewers was high: differences were eventually resolved by third-party decision. The methodological quality of the studies was moderate (mean 9.0, SD 1.7), and the outcomes of the randomized clinical trials were not related to their quality.ResultsEfforts to achieve an optimized hemodynamic condition resulted in a decreased mortality rate (relative risk ratio (RR) 0.75 (95% confidence interval (CI) 0.62 to 0.90) in all studies combined. This was due to a significantly decreased mortality in peri-operative intervention studies (RR 0.66 (95% CI 0.54 to 0.81). Overall, patients with sepsis and overt organ failure do not benefit from this method (RR 0.92 (95% CI 0.75 to 1.11)).ConclusionThis systematic review showed that interventions aimed at hemodynamic optimization reduced mortality. In particular, trials including peri-operative interventions aimed at the hemodynamic optimization of high-risk surgical patients reduce mortality. Overall, this effect was not related to the trial quality.

De novo lipogenesis in human fat and liver is linked to ChREBP-β and metabolic health

Clinical interest in de novo lipogenesis has been sparked by recent studies in rodents demonstrating that de novo lipogenesis specifically in white adipose tissue produces the insulin-sensitizing fatty acid palmitoleate. By contrast, hepatic lipogenesis is thought to contribute to metabolic disease. How de novo lipogenesis in white adipose tissue versus liver is altered in human obesity and insulin resistance is poorly understood. Here we show that lipogenic enzymes and the glucose transporter-4 are markedly decreased in white adipose tissue of insulin-resistant obese individuals compared with non-obese controls. By contrast, lipogenic enzymes are substantially upregulated in the liver of obese subjects. Bariatric weight loss restored de novo lipogenesis and glucose transporter-4 gene expression in white adipose tissue. Notably, lipogenic gene expression in both white adipose tissue and liver was strongly linked to the expression of carbohydrate-responsive element-binding protein-β and to metabolic risk markers. Thus, de novo lipogenesis predicts metabolic health in humans in a tissue-specific manner and is likely regulated by glucose-dependent carbohydrate-responsive element-binding protein activation.

Degradation of mesh coatings and intraperitoneal adhesion formation in an experimental model

In laparoscopic ventral hernia repair a mesh is placed in direct contact with the viscera, often leading to substantial adhesions. In this experimental study the ability of different coated and uncoated meshes to attenuate adhesion formation was examined.

Increased Hepatic Myeloperoxidase Activity in Obese Subjects with Nonalcoholic Steatohepatitis

Inflammation and oxidative stress are considered critical factors in the progression of nonalcoholic fatty liver disease. Myeloperoxidase (MPO) is an important neutrophil enzyme that can generate aggressive oxidants; therefore, we studied the association between MPO and nonalcoholic fatty liver disease. The distribution of inflammatory cells containing MPO in liver biopsies of 40 severely obese subjects with either nonalcoholic steatohepatitis (NASH) (n = 22) or simple steatosis (n = 18) was investigated by immunohistochemistry. MPO-derived oxidative protein modifications were identified by immunohistochemistry and correlated to hepatic gene expression of CXC chemokines and M1/M2 macrophage markers as determined by quantitative PCR. MPO plasma levels were determined by ELISA. The number of hepatic neutrophils and MPO-positive Kupffer cells was increased in NASH and was accompanied by accumulation of hypochlorite-modified and nitrated proteins, which can be generated by the MPO-H2O2 system. Liver CXC chemokine expression was higher in patients with accumulation of MPO-mediated oxidation products and correlated with hepatic neutrophil sequestration. Plasma MPO levels were elevated in NASH patients. Interestingly, neutrophils frequently surrounded steatotic hepatocytes, resembling the crown-like structures found in obese adipose tissue. Furthermore, hepatic M2 macrophage marker gene expression was increased in NASH. Our data indicate that accumulation of MPO-mediated oxidation products, partly derived from Kupffer cell MPO, is associated with induction of CXC chemokines and hepatic neutrophil infiltration and may contribute to the development of NASH.

Inter-disciplinary European guidelines on surgery of severe obesity.

In 2005, for the first time in European history, an extraordinary Expert panel named ‘The BSCG’ (Bariatric Scientific Collaborative Group), was appointed through joint effort of the major European Scientific Societies which are active in the field of obesity management. Societies that constituted this panel were: IFSO – International Federation for the Surgery of Obesity, IFSO-EC – International Federation for the Surgery of Obesity – European Chapter, EASO – European Association for Study of Obesity, ECOG – European Childhood Obesity Group, together with the IOTF (International Obesity Task Force) which was represented during the completion process by its representative. The BSCG was composed not only of the top officers representing the respective Scientific Societies (four acting presidents, two past presidents, one honorary president, two executive directors), but was balanced with the presence of many other key opinion leaders in the field of obesity. The BSCG composition allowed the coverage of key disciplines in comprehensive obesity management, as well as reflecting European geographical and ethnic diversity. This joint BSCG expert panel convened several meetings which were entirely focused on guidelines creation, during the past two years. There was a specific effort to develop clinical guidelines, which will reflect current knowledge, expertize and evidence based data on morbid obesity treatment.