Development of personalised 3D printed abdominal aortic aneurysm models with use of different materials for clinical education and training in interventional radiology

Background 3D printing is increasingly used in medical applications with studies proving its clinical value in surgical planning and simulation of complex surgical procedures. Use of patientspecific or personalised 3D printed models could serve as a useful tool in clinical education and training by practicing interventional procedures on the realistic physical models. Aims This study aimed to develop 3D printed personalised abdominal aortic aneurysm (AAA) models using different materials for the purpose of simulating interventional radiology procedure when performing endovascular aneurysm repair. Methods Anonymized Computed Tomography (CT) images of a sample case with an intrarenal AAA were selected to generate 3D volume data comprising AAA and arterial branches covering from celiac axis to common iliac arteries. The 3D segmented AAA model was printed with six different materials including resin, high impact polystyrene (HIPS), polyethylene terephthalate glycol (PETG), polylactic acid (PLA), polymethacrylate (PMMA), and thermoplastic polyurethane (TPU). The 3D printed models were scanned on a 192-slice CT scanner with and without use of contrast medium. Model accuracy in terms of AAA length and maximal transverse diameter was measured on original CT images and compared with that from these 3D printed models. Results The AAA models were successfully printed with these six different materials. 3D printed AAA models accurately replicated aortic aneurysm dimensions with mean differences less than 0.5 mm between measurements from original CT images and 3D printed models. Conclusion This study shows the feasibility of printing personalised AAA models with different materials with high accuracy of replicating aortic aneurysm. The 3D printed personalised models will be used to train interventional radiology trainees to develop their practical skills on performing endovascular aneurysm repair procedures

Clinical application of three-dimensional printed models in preoperative planning of pancoast tumour resection

BackgroundThe resection of pancoast tumours is a highly challenging procedure for cardiothoracic surgeons.  A patient-specific 3D printed model of the tumour may be useful as an adjunct to standard preoperative planning procedures.AimsThis study aims to assess the clinical value of a 3D printed pancoast tumour model as a preoperative planning tool.MethodsTwo anonymised cases of pancoast tumours were obtained and one was chosen to be 3D printed. The model was presented to two cardiothoracic surgeons with more than 10 years of experience. Interview and questionnaire sessions were conducted to sought expert opinions about the clinical value of the model as a preoperative planning tool. ResultsThe participants agreed that the 3D printed model provides an accurate representation of the exact location of the tumour in relation to surrounding structures. The hand-held model also offers a tactile approach to preoperative planning, facilitating the planning of ports placement. The model is also potentially useful in team communication and patient education, leading to improved surgical outcomes. ConclusionThis study has demonstrated the clinical value of a patient-specific 3D printed model of pancoast tumour in preoperative planning. Apart from enhancing the surgeons’ understanding of the anatomical location of the tumour, the model is also easily manipulated.  Future research could investigate the impact of 3D printed model on short to mid-term clinical outcomes

On the purported "backbone fluorescence" in protein three-dimensional fluorescence spectra

In this study, several proteins (albumin, lysozyme, insulin) and model compounds (Trp, Tyr, homopolypeptides) were used to demonstrate the origin of the fluorescence observed upon their excitation at 220–230 nm. In the last 10 years we have observed a worrying increase in the number of articles claiming that this fluorescence originates from the protein backbone, contrary to the established knowledge that UV protein emission is due to aromatic amino acids only. Overall, our data clearly demonstrate that the observed emission upon excitation at 220–230 nm is due to the excitation of Tyr and/or Trp, with subsequent emission from the lowest excited state (i.e. the same as obtained with 280 nm excitation) in agreement with Kasha's rule. Therefore, this fluorescence peak does not provide any information on backbone conformation, but simply reports on the local environment around the aromatic side chains, just as any traditional protein emission spectrum. The many papers in reputable journals erroneously reporting this peak assignment, contradicting 5 decades of prior knowledge, have led to the creation of a new dogma, where many authors and reviewers now take the purported backbone fluorescence as an established fact. We hope the current paper helps counter this new situation and leads to a reassessment of those papers that make this erroneous claim

Development of a Tissue Equivalent Gelatine Phantom for Accuracy Verification of Tissue Elasticity Measurement Using Shear Wave Elastography Ultrasound

Background Shearwave elastography ultrasound (SWE) has been increasing used in the recent decade to quantify tissue stiffness and viscoelastic properties correlate to a disease condition. Aims This study aimed to develop a low cost and reproducible gelatine phantom to verify the accuracy of tissue elasticity measurement using shear wave elastography (SWE). The effect of lesion’s size, stiffness and depth from the surface on the tissue elasticity measurement were also investigated. Methods A breast tissue-equivalent phantom embedded with spherical inclusions of different sizes, stiffness and depth from surface was constructed using gelatine. The elasticity of the spherical inclusions was determined using a commercial SWE system and compared to the elasticity determined using a high precision electromechanical microtester (gold standard for elasticity measurements). Results Statistically significant difference (p < 0.05) was found between the elasticity measured using SWE and electromechanical microtester, whereby the SWE overestimated the tissue elasticity by a mean value of 22.8 ± 15.0 kPa. The size and depth of the spherical inclusions have not imposed any effect on the elasticity measured by SWE, but the depth of shear wave detection was found limited to 8 cm from the surface. Conclusion The gelatine phantom constructed in this study could be used to verify the accuracy of the elasticity measured using SWE. The tissue elasticity measured by the SWE appeared to be overestimated compared to the gold standard. Further research would need to be carried out to determine the offset from the SWE measurement and to account for these differences

Association of maternal Vitamin D status with glucose tolerance and caesarean section in a multi-ethnic Asian cohort: the growing up in Singapore towards healthy outcomes study

10.1371/journal.pone.0142239PLoS ONE10111-16GUSTO (Growing up towards Healthy Outcomes

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Which method is best for the induction of labour?: A systematic review, network meta-analysis and cost-effectiveness analysis

Background: More than 150,000 pregnant women in England and Wales have their labour induced each year. Multiple pharmacological, mechanical and complementary methods are available to induce labour. Objective: To assess the relative effectiveness, safety and cost-effectiveness of labour induction methods and, data permitting, effects in different clinical subgroups. Methods: We carried out a systematic review using Cochrane methods. The Cochrane Pregnancy and Childbirth Group’s Trials Register was searched (March 2014). This contains over 22,000 reports of controlled trials (published from 1923 onwards) retrieved from weekly searches of OVID MEDLINE (1966 to current); Cochrane Central Register of Controlled Trials (The Cochrane Library); EMBASE (1982 to current); Cumulative Index to Nursing and Allied Health Literature (1984 to current); ClinicalTrials.gov; the World Health Organization International Clinical Trials Registry Portal; and hand-searching of relevant conference proceedings and journals. We included randomised controlled trials examining interventions to induce labour compared with placebo, no treatment or other interventions in women eligible for third-trimester induction. We included outcomes relating to efficacy, safety and acceptability to women. In addition, for the economic analysis we searched the Database of Abstracts of Reviews of Effects, and Economic Evaluations Databases, NHS Economic Evaluation Database and the Health Technology Assessment database. We carried out a network meta-analysis (NMA) using all of the available evidence, both direct and indirect, to produce estimates of the relative effects of each treatment compared with others in a network. We developed a de novo decision tree model to estimate the cost-effectiveness of various methods. The costs included were the intervention and other hospital costs incurred (price year 2012–13). We reviewed the literature to identify preference-based utilities for the health-related outcomes in the model. We calculated incremental cost-effectiveness ratios, expected costs, utilities and net benefit. We represent uncertainty in the optimal intervention using cost-effectiveness acceptability curves. Results: We identified 1190 studies; 611 were eligible for inclusion. The interventions most likely to achieve vaginal delivery (VD) within 24 hours were intravenous oxytocin with amniotomy [posterior rank 2; 95% credible intervals (CrIs) 1 to 9] and higher-dose (≥ 50 μg) vaginal misoprostol (rank 3; 95% CrI 1 to 6). Compared with placebo, several treatments reduced the odds of caesarean section, but we observed considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best three treatments, whereas vaginal misoprostol (≥ 50 μg) was most likely to increase the odds of excessive uterine activity. For other safety outcomes there were insufficient data or there was too much uncertainty to identify which treatments performed ‘best’. Few studies collected information on women’s views. Owing to incomplete reporting of the VD within 24 hours outcome, the cost-effectiveness analysis could compare only 20 interventions. The analysis suggested that most interventions have similar utility and differ mainly in cost. With a caveat of considerable uncertainty, titrated (low-dose) misoprostol solution and buccal/sublingual misoprostol had the highest likelihood of being cost-effective. Limitations: There was considerable uncertainty in findings and there were insufficient data for some planned subgroup analyses. Conclusions: Overall, misoprostol and oxytocin with amniotomy (for women with favourable cervix) is more successful than other agents in achieving VD within 24 hours. The ranking according to safety of different methods was less clear. The cost-effectiveness analysis suggested that titrated (low-dose) oral misoprostol solution resulted in the highest utility, whereas buccal/sublingual misoprostol had the lowest cost. There was a high degree of uncertainty as to the most cost-effective intervention

Protein stabilizing potential of simulated honey sugar cocktail and honey: A case study with bovine serum albumin, ovalbumin and lysozyme / Wong Yin How

The protein stabilizing potential of honey was elucidated using simulated honey sugar cocktail (SHSC) on three model proteins, namely, bovine serum albumin (BSA), ovalbumin and lysozyme. The chemical (urea and guanidine hydrochloride) and thermal denaturation curves of these proteins were shifted towards higher denaturant concentration or temperature in the presence of different SHSC concentrations (8–30%) in a concentration dependent manner, when monitored by far-UV circular dichroism (CD), fluorescence and UV-difference spectral measurements. A comparison of the spectral properties of the partially-denatured proteins (at the mid-point of transition) in the absence and the presence of SHSC using far-UV and near-UV CD, UV-difference, intrinsic fluorescence, three-dimensional fluorescence and ANS fluorescence measurements showed significant retention of globular conformation in the partially-denatured proteins in the presence of SHSC. Honey quenched the intrinsic fluorescence of BSA in a concentration dependent manner, showing complete quenching in the presence of 5% (w/v) honey. Increasing the protein concentration did not lead to any recovery in the protein fluorescence. Intrinsic fluorescence failed to produce any result in the urea denaturation of BSA in the presence of 5% (w/v) honey. Hence, chemical and thermal stabilizing potential of honey was evaluated on a model protein, BSA using far-UV CD and ANS fluorescence spectroscopy. A comparison of the chemical and thermal transition curves of BSA obtained in the absence and the presence of SHSC or honey showed greater shift of the transition curves towards higher denaturant concentration or temperature in the presence of honey compared to SHSC. Furthermore, greater retention of the globular conformation in the partially-denatured protein was also observed in the presence of honey compared to SHSC. Taken together, all these results suggested significant stabilization of native protein conformation in the presence of iv SHSC or honey against chemical and thermal denaturations, being relatively higher in the presence of honey

Patient-Specific 3D-Printed Low-Cost Models in Medical Education and Clinical Practice

3D printing has been increasingly used for medical applications with studies reporting its value, ranging from medical education to pre-surgical planning and simulation, assisting doctor–patient communication or communication with clinicians, and the development of optimal computed tomography (CT) imaging protocols. This article presents our experience of utilising a 3D-printing facility to print a range of patient-specific low-cost models for medical applications. These models include personalized models in cardiovascular disease (from congenital heart disease to aortic aneurysm, aortic dissection and coronary artery disease) and tumours (lung cancer, pancreatic cancer and biliary disease) based on CT data. Furthermore, we designed and developed novel 3D-printed models, including a 3D-printed breast model for the simulation of breast cancer magnetic resonance imaging (MRI), and calcified coronary plaques for the simulation of extensive calcifications in the coronary arteries. Most of these 3D-printed models were scanned with CT (except for the breast model which was scanned using MRI) for investigation of their educational and clinical value, with promising results achieved. The models were confirmed to be highly accurate in replicating both anatomy and pathology in different body regions with affordable costs. Our experience of producing low-cost and affordable 3D-printed models highlights the feasibility of utilizing 3D-printing technology in medical education and clinical practice