Comparing Five New Polymer Barriers for the Prevention of Intra-abdominal Adhesions in a Rat Model

Background: Intra-abdominal adhesions affect up to 93% of the patients after abdominal surgery, causing small-bowel obstruction, infertility, chronic abdominal pain, and iatrogenic bowel injury at reoperation. The efficacy of five new polymer antiadhesive barriers to avoid adhesion formation is evaluated in an ischemic button model in rats. Materials and methods: Five new, biodegradable polyurethane and copolyester-based, anti-adhesive barriers (A1, A2, A3, B1, and B2) were evaluated in separate experimental groups and compared with two control groups (hyaluronate carboxymethylcellulose barrier and no antiadhesive barrier) in an ischemic button model (n = 11 per group operated). After 14 d, the quantity and quality of the adhesions were scored macroscopically. The Kruskal-Wallis with ManneWhitney U post hoc and the Fisher's exact tests were used for data analysis. The Bonferroni correction method was applied, and a P-value <0.007 was considered significant. Results: Two animals died during surgery and follow-up. A significant reduction of adhesions to ischemic buttons was found in the A2 group (median, 3.5; interquartile range, 2.25) compared with no adhesive barrier (median, 8.0; interquartile range, 2.0) (P = 0.001). The remaining groups did not differ significantly regarding adhesion quantity or quality. Adverse events were observed in the A2, A3, and B2 groups. Conclusions: The A2 antiadhesive barrier reduced the adhesion formation significantly compared with no anti-adhesive barrier, but applicability is questionable because of extensive adverse events observed due to implantation of the anti-adhesive barrier. The Nair score appears not to be sensitive enough to detect differences in adhesion formation in this model. Future research should focus on anti-adhesive barriers that are self-adhering. (C) 2019 Published by Elsevier Inc

Brown Adipose Tissue in Morbidly Obese Subjects

BACKGROUND: Cold-stimulated adaptive thermogenesis in brown adipose tissue (BAT) to increase energy expenditure is suggested as a possible therapeutic target for the treatment of obesity. We have recently shown high prevalence of BAT in adult humans, which was inversely related to body mass index (BMI) and body fat percentage (BF%), suggesting that obesity is associated with lower BAT activity. Here, we examined BAT activity in morbidly obese subjects and its role in cold-induced thermogenesis (CIT) after applying a personalized cooling protocol. We hypothesize that morbidly obese subjects show reduced BAT activity upon cold exposure. METHODS AND FINDINGS: After applying a personalized cooling protocol for maximal non-shivering conditions, BAT activity was determined using positron-emission tomography and computed tomography (PET-CT). Cold-induced BAT activity was detected in three out of 15 morbidly obese subjects. Combined with results from lean to morbidly obese subjects (n = 39) from previous study, the collective data show a highly significant correlation between BAT activity and body composition (P<0.001), respectively explaining 64% and 60% of the variance in BMI (r = 0.8; P<0.001) and BF% (r = 0.75; P<0.001). Obese individuals demonstrate a blunted CIT combined with low BAT activity. Only in BAT-positive subjects (n = 26) mean energy expenditure was increased significantly upon cold exposure (51.5±6.7 J/s versus 44.0±5.1 J/s, P = 0.001), and the increase was significantly higher compared to BAT-negative subjects (+15.5±8.9% versus +3.6±8.9%, P = 0.001), indicating a role for BAT in CIT in humans. CONCLUSIONS: This study shows that in an extremely large range of body compositions, BAT activity is highly correlated with BMI and BF%. BAT-positive subjects showed higher CIT, indicating that BAT is also in humans involved in adaptive thermogenesis. Increasing BAT activity could be a therapeutic target in (morbid) obesity

Near-Infrared Fluorescence Imaging for Real-Time Intraoperative Guidance in Anastomotic Colorectal Surgery:A Systematic Review of Literature

Purpose: The aims of this review are to determine the feasibility of near-infrared fluorescence (NIRF) angiography in anastomotic colorectal surgery and to determine the effectiveness of the technique in improving imaging and quantification of vascularization, thereby aiding in decision making as to where to establish the anastomosis. Methods: A systematic literature search of PubMed and EMBASE was conducted. Searching through the reference lists of selected articles identified additional studies. All English language articles presenting original patient data regarding intraoperative NIRF angiography were included without restriction of type of study, except for case reports, technical notes, and video vignettes. The intervention consisted of intraoperative NIRF angiography during anastomotic colorectal surgery to assess perfusion of the colon, sigmoid, and/or rectum. Primary outcome parameters included ease of use, added surgical time, complications related to the technique, and costs. Other relevant outcomes were whether this technique changed intraoperative decision making, whether effort was taken by the authors to quantify the signal and the incidence of postoperative complications. Results: Ten studies were included. Eight of these studies make a statement about the ease of use. In none of the studies complications due to the use of the technique occurred. The technique changed the resection margin in 10.8% of all NIRF cases. The anastomotic leak rate was 3.5% in the NIRF group and 7.4% in the group with conventional imaging. Two of the included studies used an objective quantification of the fluorescence signal and perfusion, using ROIs (Hamamatsu Photonics) and IC-Calc® respectively. Conclusions: Although the feasibility of the technique seems to be agreed on by all current research, large clinical trials are mandatory to further evaluate the added value of the technique

Impact of Duodenal-Jejunal Exclusion on Satiety Hormones

OBJECTIVE: Bariatric procedures that exclude the proximal small intestine lead to significant weight loss which is probably mediated by changes in hormones that alter appetite, such as peptide YY (PYY), ghrelin, cholecystokinin (CCK), and leptin. Here, the effect of the non-surgical duodenal-jejunal bypass liner (DJBL) on concentrations of hormones implicated in appetite control was investigated. SUBJECTS: A two-center prospective study was conducted between January and December 2010. Seventeen obese subjects with type 2 diabetes were treated with the DJBL for 24 weeks. Fasting concentrations of leptin and meal responses of plasma PYY, CCK, and ghrelin were determined prior to and after implantation of the DJBL. RESULTS: At baseline, subjects had an average body weight of 116.0 +/- 5.8 kg. One week after implantation, subjects had lost 4.3 +/- 0.6 kg (p < 0.01), which progressed to 12.7 +/- 1.3 kg at week 24 (p < 0.01). Postprandial concentrations of PYY and ghrelin increased (baseline vs. week 1 vs. week 24 PYY: 2.6 +/- 0.2 vs. 4.1 +/- 0.4 vs. 4.1 +/- 0.7 nmol/L/min and ghrelin: 7.8 +/- 1.8 vs. 11.0 +/- 1.8 vs. 10.6 +/- 1.8 ng/mL/min, all p < 0.05). In parallel, the CCK response decreased (baseline vs. week 1 vs. week 24: 434 +/- 51 vs. 229 +/- 52 vs. 256 +/- 51pmol/L/min, p < 0.01). Fasting leptin concentrations also decreased (baseline vs. week 24: 98 +/- 17 vs. 53 +/- 10 ng/mL, p < 0.01). CONCLUSIONS: DJBL treatment induces weight loss paralleled by changes in concentrations of hormones involved in appetite control

Robot-Assisted vs. Conventional Laparoscopic Rectopexy for Rectal Prolapse: A Comparative Study on Costs and Time

PURPOSE: Laparoscopic rectopexy has become one of the most advocated treatments for full-thickness rectal prolapse, offering good functional results compared with open surgery and resulting in less postoperative pain and faster convalescence. However, laparoscopic rectopexy can be technically demanding. Once having mastered dexterity, with robotic assistance, laparoscopic rectopexy can be performed faster. Moreover, it shortens the learning curve in simple laparoscopic tasks. This may lead to faster and safer laparoscopic surgery. Robot-assisted rectopexy has been proven safe and feasible; however, until now, no study has been performed comparing costs and time consumption in conventional laparoscopic rectopexy vs. robot-assisted rectopexy. METHODS: Our first 14 cases of robot-assisted laparoscopic rectopexy were reviewed and compared with 19 patients who underwent conventional laparoscopic rectopexy in the same period. RESULTS: Robot-assisted laparoscopic rectopexy did not show more complications. However, the average operating time was 39 minutes longer, and costs were 557.29 (or: $745.09) higher. CONCLUSION: Robot-assisted laparoscopic rectopexy is a safe and feasible procedure but results in increased time and higher costs than conventional laparoscopy. AD - Department of Surgery, Maastricht University Hospital, Maastricht, The Netherlands

Improving Outcome in Gastrointestinal and Hepatopancreaticobiliary Surgical Oncology by Preoperative Risk Assessment and Optimization of Perioperative Care

This chapter discusses the most important challenges in the perioperative phase of the oncology patient undergoing surgery of the gastrointestinal tract. Because of the aging population, the surgeon is ever more confronted with frail patients at risk for an adverse surgical outcome. The chapter therefore reviews factors contributing to an impaired postoperative outcome such as sarcopenia, frailty, cachexia, and malnutrition and gives an insight into their pathophysiology. Next, it provides an overview of validated preoperative classification systems to identify the patients at risk for surgical complications. Furthermore, it discusses the most essential recommendations of standardized care for patients undergoing hepatopancreaticobiliary, gastric, and colorectal surgery. Special attention is paid to the use of clinical pathways in the perioperative phase that are aimed at a multimodal approach of reducing surgical morbidity by lowering the perioperative physiological and psychological stress. Recent literature is discussed regarding care in the intensive care unit, and the final paragraph focuses on improving postoperative outcome by means of prehabilitation or exercise as well as dietary interventions and optimized nutrition

Development of a Supramolecular Hydrogel for Intraperitoneal Injections

Local intraperitoneal drug administration is considered a challenging drug delivery route. The therapeutic efficiency is low, mainly due to rapid clearance of drugs. To increase the intraperitoneal retention time of specific drugs, a pH-sensitive supramolecular hydrogel that can act as a drug delivery vehicle is developed. To establish the optimal formulation of the hydrogel and to study its feasibility, safety, and tissue compatibility, in vitro, postmortem, and in vivo experiments are performed. In vitro tests reveal that a hydrogelator formulation with pH ≥ 9 results in a constant viscosity of 0.1 Pa·s. After administration postmortem, the hydrogel covers the parietal and visceral peritoneum with a thin, soft layer. In the subsequent in vivo experiments, 14 healthy rats are subjected to intraperitoneal injection with the hydrogel. Fourteen and 28 days after implantation, the animals are euthanized. Intraperitoneal exposure to the hydrogel is not resulted in significant weight loss or discomfort. Moreover, no macroscopic adverse effects or signs of organ damage are detected. In several intra-abdominal tissues, vacuolated macrophages are found indicating a physiological degradation of the synthetic hydrogel. This study demonstrates that the supramolecular hydrogel is safe for intraperitoneal application and that the hydrogel shows good tissue compatibility in rats.</p