177 research outputs found
Substrate Effect on the High Temperature Oxidation Behavior of a Pt-modified Aluminide Coating. Part II: Long-term Cyclic-oxidation Tests at 1,050 C
This second part of a two-part study is devoted to the effect of the substrate on the long-term, cyclic-oxidation behavior at 1,050 C of RT22 industrial coating deposited on three Ni-base superalloys (CMSX-4, SCB, and IN792). Cyclicoxidation tests at 1,050 C were performed for up to 58 cycles of 300 h (i.e., 17,400 h of heating at 1,050 C). For such test conditions, interdiffusion between the coating and its substrate plays a larger role in the damage process of the system than during isothermal tests at 900, 1,050, and 1,150 C for 100 h and cyclicoxidation tests at 900 C which were reported in part I [N. Vialas and D. Monceau,
Oxidation of Metals 66, 155 (2006)]. The results reported in the present paper show that interdiffusion has an important effect on long-term, cyclic-oxidation resistance, so that clear differences can be observed between different superalloys protected with the same aluminide coating. Net-mass-change (NMC) curves show the better cyclic-oxidation behavior of the RT22/IN792 system whereas uncoated CMSX-4 has the best cyclic-oxidation resistance among the three superalloys studied. The importance of the interactions between the superalloy substrate and its coating is then demonstrated. The effect of the substrate on cyclic-oxidation behavior is related to the extent of oxide scale spalling and to the evolution of microstructural
features of the coatings tested. SEM examinations of coating surfaces and cross sections show that spalling on RT22/CMSX-4 and RT22/SCB was favored by the presence of deep voids localized at the coating/oxide interface. Some of these voids can act as nucleation sites for scale spallation. The formation of such interfacial
voids was always observed when the b to c0 transformation leads to the formation of a two-phase b/c0 layer in contact with the alumina scale. On the contrary, no voids
were observed in RT22/IN792, since this b to c0 transformation occurs gradually by an inward transformation of b leading to the formation of a continuous layer of c0
phase, parallel to the metal/scale interface
Health economic analysis of laparoscopic lavage versus Hartmann's procedure for diverticulitis in the randomized DILALA trial
BACKGROUND: Open surgery with resection and colostomy (Hartmann's procedure) has been the standard treatment for perforated diverticulitis with purulent peritonitis. In recent years laparoscopic lavage has emerged as an alternative, with potential benefits for patients with purulent peritonitis, Hinchey grade III. The aim of this study was to compare laparoscopic lavage and Hartmann's procedure with health economic evaluation within the framework of the DILALA (DIverticulitis – LAparoscopic LAvage versus resection (Hartmann's procedure) for acute diverticulitis with peritonitis) trial. METHODS: Clinical effectiveness and resource use were derived from the DILALA trial and unit costs from Swedish sources. Costs were analysed from the perspective of the healthcare sector. The study period was divided into short‐term analysis (base‐case A), within 12 months, and long‐term analysis (base‐case B), from inclusion in the trial throughout the patient's expected life. RESULTS: The study included 43 patients who underwent laparoscopic lavage and 40 who had Hartmann's procedure in Denmark and Sweden during 2010–2014. In base‐case A, the difference in mean cost per patient between laparoscopic lavage and Hartmann's procedure was €–8983 (95 per cent c.i. –16 232 to –1735). The mean(s.d.) costs per patient in base‐case B were €25 703(27 544) and €45 498(38 928) for laparoscopic lavage and Hartmann's procedure respectively, resulting in a difference of €–19 794 (95 per cent c.i. –34 657 to –4931). The results were robust as demonstrated in sensitivity analyses. CONCLUSION: The significant cost reduction in this study, together with results of safety and efficacy from RCTs, support the routine use of laparoscopic lavage as treatment for complicated diverticulitis with purulent peritonitis
Two-year results of the randomized clinical trial DILALA comparing laparoscopic lavage with resection as treatment for perforated diverticulitis
Abstract
Background
Traditionally, perforated diverticulitis with purulent peritonitis was treated with resection and colostomy (Hartmann's procedure), with inherent complications and risk of a permanent stoma. The DILALA (DIverticulitis – LAparoscopic LAvage versus resection (Hartmann's procedure) for acute diverticulitis with peritonitis) and other randomized trials found laparoscopic lavage to be a feasible and safe alternative. The medium-term follow-up results of DILALA are reported here.
Methods
Patients were randomized during surgery after being diagnosed with Hinchey grade III perforated diverticulitis at diagnostic laparoscopy. The primary outcome was the proportion of patients with one or more secondary operations from 0 to 24 months after the index procedure in the laparoscopic lavage versus Hartmann's procedure groups. The trial was registered as ISRCTN82208287.
Results
Forty-three patients were randomized to laparoscopic lavage and 40 to Hartmann's procedure. Patients in the lavage group had a 45 per cent reduced risk of undergoing one or more operations within 24 months (relative risk 0·55, 95 per cent c.i. 0·36 to 0·84; P = 0·012) and had fewer operations (ratio 0·51, 95 per cent c.i. 0·31 to 0·87; P = 0·024) compared with those in the Hartmann's group. No difference was found in mean number of readmissions (1·37 versus 1·50; P = 0·221) or mortality between patients randomized to laparoscopic lavage or Hartmann's procedure. Three patients in the lavage group and nine in the Hartmann's group had a colostomy at 24 months.
Conclusion
Laparoscopic lavage is a better option for perforated diverticulitis with purulent peritonitis than open resection and colostomy.
</jats:sec
Quality of life in a randomized trial of early closure of temporary ileostomy after rectal resection for cancer (EASY trial)
Early Closure of a Temporary Ileostomy in Patients With Rectal Cancer:A Multicenter Randomized Controlled Trial
The objective was to study morbidity and mortality associated with early closure (8-13 days) of a temporary stoma compared with standard procedure (closure after > 12 weeks) after rectal resection for cancer.A temporary ileostomy may reduce the risk of pelvic sepsis after anastomotic dehiscence. However, the temporary ileostomy is afflicted with complications and requires a second surgical procedure (closure) with its own complications. Early closure of the temporary ileostomy could reduce complications for rectal cancer patients.Early closure (8-13 days after stoma creation) of a temporary ileostomy was compared with late closure (>12 weeks) in a multicenter randomized controlled trial, EASY (www.clinicaltrials.gov, NCT01287637) including patients undergoing rectal resection for cancer. Patients with a temporary ileostomy without signs of postoperative complications were randomized to closure at 8 to 13 days or late closure (>12 weeks after index surgery). Clinical data were collected up to 12 months. Complications were registered according to the Clavien-Dindo Classification of Surgical Complications, and Comprehensive Complication Index was calculated.The trial included 127 patients in eight Danish and Swedish surgical departments, and 112 patients were available for analysis. The mean number of complications after index surgery up to 12 months follow up was significantly lower in the intervention group (1.2) compared with the control group (2.9), P < 0.0001.It is safe to close a temporary ileostomy 8 to 13 days after rectal resection and anastomosis for rectal cancer in selected patients without clinical or radiological signs of anastomotic leakage.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/4.0
Management of intra-abdominal infections : recommendations by the WSES 2016 consensus conference
This paper reports on the consensus conference on the management of intra-abdominal infections (IAIs) which was held on July 23, 2016, in Dublin, Ireland, as a part of the annual World Society of Emergency Surgery (WSES) meeting. This document covers all aspects of the management of IAIs. The Grading of Recommendations Assessment, Development and Evaluation recommendation is used, and this document represents the executive summary of the consensus conference findings.Peer reviewe
Treatment of acute diverticulitis laparoscopic lavage vs. resection (DILALA): study protocol for a randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>Perforated diverticulitis is a condition associated with substantial morbidity. Recently published reports suggest that laparoscopic lavage has fewer complications and shorter hospital stay. So far no randomised study has published any results.</p> <p>Methods</p> <p>DILALA is a Scandinavian, randomised trial, comparing laparoscopic lavage (LL) to the traditional Hartmann's Procedure (HP). Primary endpoint is the number of re-operations within 12 months. Secondary endpoints consist of mortality, quality of life (QoL), re-admission, health economy assessment and permanent stoma. Patients are included when surgery is required. A laparoscopy is performed and if Hinchey grade III is diagnosed the patient is included and randomised 1:1, to either LL or HP. Patients undergoing LL receive > 3L of saline intraperitoneally, placement of pelvic drain and continued antibiotics. Follow-up is scheduled 6-12 weeks, 6 months and 12 months. A QoL-form is filled out on discharge, 6- and 12 months. Inclusion is set to 80 patients (40+40).</p> <p>Discussion</p> <p>HP is associated with a high rate of complication. Not only does the primary operation entail complications, but also subsequent surgery is associated with a high morbidity. Thus the combined risk of treatment for the patient is high. The aim of the DILALA trial is to evaluate if laparoscopic lavage is a safe, minimally invasive method for patients with perforated diverticulitis Hinchey grade III, resulting in fewer re-operations, decreased morbidity, mortality, costs and increased quality of life.</p> <p>Trial registration</p> <p>British registry (ISRCTN) for clinical trials <a href="http://www.controlled-trials.com/ISRCTN82208287">ISRCTN82208287</a><url>http://www.controlled-trials.com/ISRCTN82208287</url></p
Survivorship issues in long-term survivors of locally recurrent rectal cancer: A qualitative study
Aim
There are increasing numbers of long-term survivors following curative treatment for locally recurrent rectal cancer (LRRC); however, their experiences remain relatively underreported. The aim of this qualitative study was to identify the long-term survivorship issues relevant to these patients.
Method
Adults who remained disease free >3 years following treatment for LRRC were invited to participate in an international multicentre study. Semistructured qualitative interviews were conducted either in person, via telephone or via Microsoft Teams and were analysed using a framework method of thematic analysis.
Results
A total of 26 participants were recruited from 11 sites in seven countries. Sixteen (61.5%) participants were male, the median age was 70.5 (33.0–85.0) years, participants were a median of 5.0 (3.0–17.0) years posttreatment, most had undergone surgery for LRRC (n = 24, 92.3%), two participants received neoadjuvant chemo/radiation for LRRC with a complete response. Eight major survivorship themes were identified: (1) experience of long-term follow-up care, (2) unmet needs and areas for improvement, (3) long-term physical effects of cancer and treatment, (4) living with a stoma, urostomy or other urinary device, (5) long-term psychological impact, (6) impact on sexual function and intimate relationships, (7) impact on daily life and (8) feelings surrounding life now, adapting and the future.
Conclusion
Participants experienced a wide range of long-term survivorship issues, reflecting the complexity of both LRRC and its treatment. Despite this, most had adapted well. Further work regarding survivorship care in LRRC is required to address the unmet needs and issues highlighted in this study, such as support regarding sexual function
Inhibition of dendritic cell migration by transforming growth factor-β1 increases tumor-draining lymph node metastasis
<p>Abstract</p> <p>Background</p> <p>Transforming growth factor (TGF)-β is known to be produced by progressor tumors and to immobilize dendritic cells (DCs) within those tumors. Moreover, although TGF-β1 has been shown to promote tumor progression, there is still no direct, in vivo evidence as to whether TGF-β1 is able to directly induce distant metastasis.</p> <p>Methods</p> <p>To address that issue and investigate the mechanism by which TGF-β1 suppresses DC activity, we subdermally inoculated mouse ears with squamous cell carcinoma cells stably expressing TGF-β1 or empty vector (mock).</p> <p>Results</p> <p>The numbers of DCs within lymph nodes draining the resultant TGF-β1-expressing tumors was significantly lower than within nodes draining tumors not expressing TGF-β1. We then injected fluorescently labeled bone marrow-derived dendritic cells into the tumors, and subsequent analysis confirmed that the tumors were the source of the DCs within the tumor-draining lymph nodes, and that there were significantly fewer immature DCs within the nodes draining TGF-β1-expressing tumors than within nodes draining tumors not expressing TGF-β1. In addition, 14 days after tumor cell inoculation, lymph node metastasis occurred more frequently in mice inoculated with TGF-β1 transfectants than in those inoculated with the mock transfectants.</p> <p>Conclusions</p> <p>These findings provide new evidence that tumor-derived TGF-β1 inhibits migration of DCs from tumors to their draining lymph nodes, and this immunosuppressive effect of TGF-β1 increases the likelihood of metastasis in the affected nodes.</p
Microvessel density as new prognostic marker after radiotherapy in rectal cancer
<p>Abstract</p> <p>Background</p> <p>The extent of angiogenesis is an important prognostic factor for colorectal carcinoma, however, there are few studies concerning changes in angiogenesis with radiotherapy (RTX). Our aim was to investigate changes in tumor angiogenesis influenced by radiotherapy to assess the prognostic value of angiogenesis the microvessel density (MVD) in overall survival after radiotherapy.</p> <p>Methods</p> <p>Tumor specimens were taken from 101 patients resected for rectal cancer. The patients were divided into three groups according to the treatment they received before surgery (not treated, a short course, or long course of RTX). Tumor specimens were paraffin-embedded and immunohistochemistry was performed with primary antibody against CD-34 to count MVD.</p> <p>Results</p> <p>MVD was significantly lower in the group of patients treated with a long course of RTX (p <0.025). The mean MVD for the long RTX group was 134.8; for the short RTX group – 192.5; and for those not treated with RTX – 193.0. There were no significant statistical correlations between MVD and age, sex, grade of tumor differentiation (G) and tumor size (T) in those untreated with RTX. In long RTX group we found a significant prognostic rate for MVD when the density cut off was near 130 with 92.3% sensitivity and 64.7% specificity. When the MVD was lower than a cut off of 130, the survival period significantly increased (p = 0.001), the mortality rate is significantly higher if the MVD is higher than 130 (microvessel/mm<sup>2</sup>) (1953.047; p = 0.002), if the histological grade is moderate/poor (127.407; p = 0.013), if the tumor is T3/T4 (111.618; p = 0.014), and if the patient is male (17.92; p = 0.034) adjusted by other variable in model.</p> <p>Conclusion</p> <p>Our results show that a long course of radiotherapy significantly decreased angiogenesis in rectal cancer tissue. MVD was found to be a favourable marker for tumor behaviour during RTX and a predictor of overall survival after long course of RTX. Further investigations are now needed to determine the changes in angiogenesis during a shorter course of RTX.</p
- …
