A viewpoint on material and design considerations for oesophageal stents with extended lifetime

Oesophageal stents are meshed tubular implants designed to maintain patency of the oesophageal lumen and attenuate the symptoms of oesophageal cancer. Oesophageal cancers account for one in twenty cancer diagnoses and can lead to dysphasia, malnutrition and the diminishment of patient quality of life (QOL). Self-expanding oesophageal stents are the most common approach to attenuate these symptoms. Recent advances in oncological therapy have enabled patient survival beyond the lifetime of current devices. This introduces new complications for palliation, driving the need for innovation in stent design. This review identifies the factors responsible for stent failure. It explores the challenges of enhancing the longevity of stent therapies and outlines solutions to improving clinical outcomes. Discussions focus on the role of stent materials, construction methods, and coatings upon device performance. We found three key stent enhancement strategies currently used; material surface treatments, anti-migratory modifications, and biodegradable skeletons. Furthermore, radioactive and drug eluting stent designs were identified as emerging novel treatments. In conclusion, the review offers an overview of remaining key challenges in oesophageal stent design and potential solutions. It is clear that further research is needed to improve the clinical outcome of stents and patient QOL

UK guidelines on oesophageal dilatation in clinical practice

These are updated guidelines which supersede the original version published in 2004. This work has been endorsed by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG) under the auspices of the oesophageal section of the BSG. The original guidelines have undergone extensive revision by the 16 members of the Guideline Development Group with representation from individuals across all relevant disciplines, including the Heartburn Cancer UK charity, a nursing representative and a patient representative. The methodological rigour and transparency of the guideline development processes were appraised using the revised Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. Dilatation of the oesophagus is a relatively high-risk intervention, and is required by an increasing range of disease states. Moreover, there is scarcity of evidence in the literature to guide clinicians on how to safely perform this procedure. These guidelines deal specifically with the dilatation procedure using balloon or bougie devices as a primary treatment strategy for non-malignant narrowing of the oesophagus. The use of stents is outside the remit of this paper; however, for cases of dilatation failure, alternative techniques—including stents—will be listed. The guideline is divided into the following subheadings: (1) patient preparation; (2) the dilatation procedure; (3) aftercare and (4) disease-specific considerations. A systematic literature search was performed. The Grading of Recommendations Assessment, Develop­ment and Evaluation (GRADE) tool was used to evaluate the quality of evidence and decide on the strength of recommendations made

Risk of Bowel Obstruction in Patients Undergoing Neoadjuvant Chemotherapy for High-risk Colon Cancer

Objective: This study aimed to identify risk criteria available before the point of treatment initiation that can be used to stratify the risk of obstruction in patients undergoing neoadjuvant chemotherapy (NAC) for high-risk colon cancer. Background: Global implementation of NAC for colon cancer, informed by the FOxTROT trial, may increase the risk of bowel obstruction. Methods: A case-control study, nested within an international randomized controlled trial (FOxTROT; ClinicalTrials.gov: NCT00647530). Patients with high-risk operable colon cancer (radiologically staged T3-4 N0-2 M0) that were randomized to NAC and developed large bowel obstruction were identified. First, clinical outcomes were compared between patients receiving NAC in FOxTROT who did and did not develop obstruction. Second, obstructed patients (cases) were age-matched and sex-matched with patients who did not develop obstruction (controls) in a 1:3 ratio using random sampling. Bayesian conditional mixed-effects logistic regression modeling was used to explore clinical, radiologic, and pathologic features associated with obstruction. The absolute risk of obstruction based on the presence or absence of risk criteria was estimated for all patients receiving NAC. Results: Of 1053 patients randomized in FOxTROT, 699 received NAC, of whom 30 (4.3%) developed obstruction. Patients underwent care in European hospitals including 88 UK, 7 Danish, and 3 Swedish centers. There was more open surgery (65.4% vs 38.0%, P=0.01) and a higher pR1 rate in obstructed patients (12.0% vs 3.8%, P=0.004), but otherwise comparable postoperative outcomes. In the case-control–matched Bayesian model, 2 independent risk criteria were identified: (1) obstructing disease on endoscopy and/or being unable to pass through the tumor [adjusted odds ratio: 9.09, 95% credible interval: 2.34–39.66] and stricturing disease on radiology or endoscopy (odds ratio: 7.18, 95% CI: 1.84–32.34). Three risk groups were defined according to the presence or absence of these criteria: 63.4% (443/698) of patients were at very low risk (10%). Conclusions: Safe selection for NAC for colon cancer can be informed by using 2 features that are available before treatment initiation and identifying a small number of patients with a high risk of preoperative obstruction

Ultrasound-guided day-case wide-bore percutaneous mucin aspiration in advanced pseudomyxoma peritonei.

From PubMed via Jisc Publications RouterHistory: received 2022-08-18, revised 2023-01-26, accepted 2023-01-26Publication status: aheadofprintTo evaluate percutaneous ultrasound-guided day-case mucin aspiration in advanced pseudomyxoma peritonei (PMP) using a wide-bore drain with regards to its safety and efficacy. All patients who underwent percutaneous mucin aspiration for PMP between 2019-2021 at a single national peritoneal tumour service were included in this study. Under local anaesthesia, a suction-enabled 28-32 F catheter was used for drainage following wire-guided track dilatation. The volume drained and difference in abdominal girth pre- and post-procedure were measured. Patients graded difficulty in breathing and abdominal discomfort pre- and post-procedure. Histology reports were reviewed. Sixteen patients received 56 percutaneous mucin aspirations between 2019-2021. The aetiology was a low-grade appendiceal mucinous neoplasm (LAMN) in 50% of patients. The mean amount of mucin drained was 7,320 ± 3,000ml (range 300-13,500 ml). The mean reduction in abdominal girth post-procedure was 12.2 ± 5 cm (range 0-27 cm). Only grade 1 complications were observed. Percutaneous ultrasound-guided day-case aspiration of mucin for advanced and recurrent PMP using a wide-bore drain is a safe and effective procedure. It may be used in the palliative setting or as a bridge to surgery in the very symptomatic patient or if there is a reversible contraindication to surgery. [Abstract copyright: Copyright © 2023. Published by Elsevier Ltd.

Acute pancreatitis: an under-recognized risk of percutaneous transhepatic distal biliary intervention

Objective: Percutaneous transhepatic biliary intervention (PTBI) plays an important role in the management of biliary obstruction, and this may be complicated by acute pancreatitis. The aim of this study was to assess the incidence of acute pancreatitis following PTBI. Patients and methods: Patients who underwent PTBI between January 1992 and December 2003 in a tertiary referral centre were identified from the hospital database. Patients who did not have their amylase measured post-procedure were excluded, as acute pancreatitis might have been missed. Acute pancreatitis was defined as hyperamylasaemia of three times or more above normal in association with abdominal pain. Results: Over a 12-year period, 331 patients underwent 613 procedures. Serum amylase was measured after 134 procedures (21.9%) and was elevated in 26 of those (19.4%). There was no difference in the frequency of hyperamylasaemia between proximal and distal PTBI (14/73 [19.2%] vs 12/61 [19.7%] procedures, p=NS). However, acute pancreatitis developed after 4 of 61 (6.6%) distal PTBI (stent, n=3; internal–external catheter insertion, n=1) but not after proximal PTBI (cholangiography or external drainage) (p=0.041). The attacks were mild in three of the four patients. No pancreatitis-related deaths occurred. Conclusion: The risk of acute pancreatitis after distal PTBI is under-recognized and should be considered as a consent issue in patients scheduled for distal PTBI and when post-procedure abdominal pain ensues

A Formalization of ODMG Queries

The ODMG proposal has helped to focus the work on object-oriented databases (OODBs) onto a common object model and query language. Nevertheless there are several shortcomings of the current proposal stemming from the adaption of concepts of object-oriented programming and a lack of formalization. In this paper we present a formalization of the ODMG model and the OQL query language that is used in the CROQUE project as a basis for query optimization. An essential part is a complete, formally sound type system that allows us to reason about the types of intermediate query results and gives rise to fully orthogonal queries, including useful extensions of projections and set operations. 1 INTRODUCTION For a long time, the evolution of OODB seemed to disperse in quite different directions: there were rather distinct object-oriented database models (OODMs) either based on (nested) relational formalisms or OOPL-like notions, and hardly any consensus about the structure and formalization of q..