Rendezvous endovascular common carotid artery stenting (RECCAS) technique for symptomatic steno-occlusive disease.

This report describes a patient who presented with acute but transient right arm weakness and altered sensation secondary to severe stenosis of the left common carotid artery (CCA) origin. Endovascular stenting of the stenosed origin was achieved utilising a novel rendezvous technique through combined retrograde common carotid artery and anterograde transfemoral approaches. This technique has numerous potential advantages over traditional transfemoral endovascular and open retrograde common carotid artery approaches. It allows increased procedural control and success in traversing the stenosis and provides a smooth transition for the stent delivery catheter. An open cutdown procedure or open surgical technique is not required. Our patient recovered well from the procedure with no complications within the three-month follow up period.

Contemporary endovascular management of splenic vascular pathologies.

The spleen is a commonly injured organ and the splenic vasculature is also susceptible to inflammation and trauma, often resulting in aneurysm formation. Splenic artery aneurysms carry a high risk of rupture and are associated with high mortality and morbidity. Due to the advances in endovascular techniques and devices, endovascular management of splenic vascular pathologies is now considered a first-line strategy. Endovascular embolisation and advance techniques including balloon- or stent-assisted coil embolisation enables minimally invasive management option while preserving splenic function.

A density functional study on the formaldehyde recognition by Al-doped ZnO nanosheet.

Experimental works have shown that doping ZnO nanosheets by the Al atom meaningfully increases their sensitivity toward HCHO gas. Here, we applied density functional theory calculations to study the Al-doping effect on the sensitivity of a ZnO nanosheet to HCHO gas, explaining the experimental results. We found that the pristine ZnO nanosheet weakly interacts with the HCHO with adsorption energy (Ead) of -9.3 kcal/mol, and the sensing response (S) value of 2.2 at 623 K. After the Al-doping process, the Ead and S values increase to -40.7 kcal/mol and 83.9, respectively, indicating an excellent agreement with the experimental results. We showed a relation between the HOMO-LUMO gap and the S value, confirming with the experimental results. Also, the proposed Al-doped ZnO nanosheet shows a good selectivity to HCHO gas at the presence of H2, NH3, C2H5OH, CO, and CH4 gases. A short recovery time of 18 s is predicted for Al-ZnO-based sensor which is comparable with the experimental value of 26 s. Finally, we conclude that the Al-doping makes the ZnO nanosheet a promising HCHO gas sensor with a high sensitivity, an excellent selectivity, and short recovery time.

Women in interventional radiology: insights into Australia's gender gap.

AIM: To assess differences in the exposure, teaching, knowledge, appreciation, and interest in interventional radiology (IR) between male and female doctors prior to specialisation and to identify potential predisposing factors to the gender inequality in interventional radiology. MATERIALS AND METHODS: A prospective cross-sectional multicentre study was conducted using in-person and web-based distribution of a voluntary, anonymous questionnaire to junior doctors yet to commence specialisation at 11 health services across two Australian states. RESULTS: Complete responses were provided by 333 junior doctors (21.9% response rate). Women were significantly less likely than men to consider a career in IR (13.1% versus 29.7%, p < 0.001). No other statistically significant gender disparities were identified, as both men and women reported low levels of prior teaching and exposure to IR, strong belief in the importance of IR, and suboptimal knowledge of IR. CONCLUSIONS: The gender gap amongst practising Australian interventional radiologists is perpetuated by a consistent gender gap in upcoming junior doctors' desire to pursue IR. This disparity exists despite junior doctors receiving the same exposure and opportunities in interventional radiology, possibly suggesting that preconceived stereotypes or psychosocial factors deter females from pursuing this procedural, male-dominated subspecialty. Future qualitative studies are required to confirm this hypothesis, in conjunction with prospective, experimental trials to determine whether changes in education, mentorship, and advocacy can promote gender equality.

Kernicterus with abnormal high-signal changes bilaterally in the globus pallidus: A case report.

Kernicterus is a relatively rare consequence of hyperbilirubinemia. There is an important role for MRI imaging for this entity in the appropriate clinical context as there are distinct signal changes in the globus pallidus. A case report and image findings are presented

eDoctor: machine learning and the future of medicine.

Machine learning (ML) is a burgeoning field of medicine with huge resources being applied to fuse computer science and statistics to medical problems. Proponents of ML extol its ability to deal with large, complex and disparate data, often found within medicine and feel that ML is the future for biomedical research, personalized medicine, computer-aided diagnosis to significantly advance global health care. However, the concepts of ML are unfamiliar to many medical professionals and there is untapped potential in the use of ML as a research tool. In this article, we provide an overview of the theory behind ML, explore the common ML algorithms used in medicine including their pitfalls and discuss the potential future of ML in medicine.

Current evidence for endovascular therapy in stroke and remaining uncertainties.

Class 1 level A evidence now supports endovascular thrombectomy as best practice in the management of large vessel occlusion acute ischaemic stroke. However, significant questions pertaining to initial imaging, radiological assessment, patient selection and therapeutic limits remain unanswered. A specific cohort of patients who benefit from endovascular thrombectomy has been established, although current uncertainties regarding selection of those not meeting top-tier evidence criteria may potentially deny certain patients the benefit of intervention. This is of particular relevance in patients presenting in a delayed manner. Whilst superior outcomes are achieved with reduced time to endovascular reperfusion, denying patients intervention based on symptom duration alone may not be appropriate. Advanced understanding of ischaemic stroke pathophysiology supports an individualized approach to patient evaluation, given variance in the rate of ischaemic core progression and the extent of salvageable penumbra. Physiological imaging techniques may therefore be utilized to better inform patient selection for endovascular thrombectomy and evidence suggests that a transition from time-based to tissue-based therapeutic thresholds may be of greater value. Multiple ongoing randomized controlled trials aim to further define the benefit of endovascular thrombectomy and it is hoped that these results will advance, and possibly broaden, patient selection criteria to ensure that maximum benefit from the intervention may be achieved.

Vertebroplasty and Kyphoplasty for Osteoporotic Vertebral Fractures: What Are the Latest Data?

Osteoporotic vertebral compression fractures frequently result in significant morbidity and health care resource use. For patients with severe and disabling pain, vertebral augmentation (vertebroplasty and kyphoplasty) is often considered. Although vertebroplasty was introduced >30 years ago, there are conflicting opinions regarding the role of these procedures in the treatment of osteoporotic vertebral compression fractures. This review article updates clinicians on the published prospective randomized controlled data, including the most recent positive trials that followed initial negative trials in 2009. Analysis of multiple national claim datasets has also provided further insight into the utility of these procedures. Finally, we considered the recent recommendations of national organizations and medical societies that advise on the use of vertebral augmentation procedures for osteoporotic vertebral compression fractures.

Outcomes of endovascular treatment for acute large-vessel ischaemic stroke more than 6 h after symptom onset.

BACKGROUND AND OBJECTIVES: Benefit from endovascular thrombectomy (EVT) for large-vessel occlusion (LVO) acute ischaemic stroke (AIS) is well demonstrated. Furthermore, emerging evidence supports efficacy in appropriately selected patients treated beyond current recommendations of 6 h. We evaluated clinical outcomes in patients undergoing late EVT at our institution. METHODS: Retrospective review of prospectively collected clinical database on 355 patients who underwent EVT for LVO AIS. Data collected consisted of patient demographics, radiological findings and outcome details. Outcomes, including 90-day functional status, recanalization, symptomatic intracranial haemorrhage (sICH) and 90-day mortality, for patients undergoing EVT <6 h, >6 h, and >7.3 h, were compared. RESULTS: A total of 355 patients underwent EVT for LVO AIS at our institution during the review period, with 74 (21%) patients treated ≥6 h from symptom onset. Successful recanalization was achieved in 285 (80%) patients, with 228 (81%) achieving a mTICI ≥2b in the <6 h group, and 57 (77%) in the >6 h group (P = 0.429). Ninety-day functional independence (mRS 0-2) was achieved in 162 (46%) patients, with 130 (46%) achieving a mRS of 0-2 in the <6 h group, and 32 (43%) in the >6 h group (P = 0.643). No significant differences were found in rates of sICH or 90-day mortality. No significant differences in functional independence, recanalization rates, sICH or mortality were identified in patients treated with EVT >7.3 h compared to <7.3 h. CONCLUSIONS: In appropriately selected patients, EVT >6 h was associated with comparable outcomes to those treated <6 h. These data support a physiological approach to patient selection.

Endovascular Therapy Research in Lower Limb Peripheral Arterial Disease Published Over a 5-Year Period: Who is Publishing and Where?

INTRODUCTION: Peripheral arterial disease (PAD) is being increasingly managed by endovascular therapies. In this study, we identified the clinical services publishing research as well as the journals of publication over a 5-year period. METHODS: Twenty keywords and phrases related to endovascular intervention were identified, and a literature search was performed through the PubMed database from January 2009 to January 2014. Inclusion criteria were English language, study population more than five patients, and matching the keyword search. Eligible studies were collated into a database and classified by journal of publication, PubMed number, article title, publishing clinical service, type of publication, country of origin, and authors. RESULTS: 825 studies from 114 different journals were identified. 297 papers were excluded. Of the 528 included papers, 204 (39%) were published by Vascular Surgery (VS), 157 (30%) by Interventional Radiology (IR), 101 (19%) by Cardiology, 43 (8%) by Angiology, 6 (1%) by Vascular Medicine, and 17 (3%) from miscellaneous services. 283 (54%) studies originated from Europe, 157 (30%) from North America, 76 (14%) from Asia, 6 from Australia, 3 each from South America and Africa. IR published the most papers on PAD endovascular intervention in Europe with VS second while this trend was reversed in the USA. The 528 papers were published in 98 different journals with retrospective case series (72%), the majority. CONCLUSION: IR continues to play a significant research role in endovascular intervention in PAD, particularly in Europe, and specifically in below the knee intervention, pedal intervention, and drug-eluting technologies.

A review of percutaneous transhepatic biliary drainage at a tertiary referral centre.

AIM: To review percutaneous biliary drainage (PBD) procedures performed in Beaumont Hospital, Dublin, Ireland, over a 6-year period, to determine the 30-day morbidity and mortality. MATERIALS AND METHODS: A total of 119 patients undergoing 193 PBD procedures were identified over a 6 year period. Of the patients, 6.7% (eight patients) had stone disease, 63% (75 patients) had a malignancy, and the remainder were diagnosed with other conditions. Standard techniques of PBD and biliary stent insertion were applied, with 73 patients (61%) having same-day procedures and all undergoing gelfoam embolisation of percutaneous tracts. All patients received intravenous prophylactic antibiotics and intravenous hydration prior to PBD. RESULTS: The technical success rate was 97%, with a mean drop of 105 mmol/l between pre- and post-procedure bilirubin. Thirty-day mortality was 10.9% (13 deaths), with major and minor morbidities of 5% (six patients) and 7.6% (nine patients), respectively. Major complications included sepsis in two patients, major haemorrhage in two patients, and renal failure in two patients. Minor complications included infection in seven patients, bile leak causing self-limiting pain in one patient, and minor haemorrhage in one patient. CONCLUSION: The study confirms that PBD and stent insertion is a safe and effective technique in Beaumont Hospital, associated with an overall acceptable morbidity and mortality comparable with other studies.

The Introduction of an Undergraduate Interventional Radiology (IR) Curriculum: Impact on Medical Student Knowledge and Interest in IR.

INTRODUCTION: Interventional radiology (IR) plays a vital role in modern medicine, with increasing demand for services, but with a shortage of experienced interventionalists. The aim of this study was to determine the impact of a recently introduced IR curriculum on perception, knowledge, and interest of medical students regarding various aspects of IR. METHODS: In 2014, an anonymous web-based questionnaire was sent to 309 4th year medical students in a single institution within an EU country, both before and after delivery of a 10-h IR teaching curriculum. RESULTS: Seventy-six percent (236/309) of the respondents participated in the pre-IR module survey, while 50% (157/309) responded to the post-IR module survey. While 62% (147/236) of the respondents reported poor or no knowledge of IR compared to other medical disciplines in the pre-IR module survey, this decreased to 17% (27/157) in the post-IR module survey. The correct responses regarding knowledge of selected IR procedures improved from 70 to 94% for venous access, 78 to 99% for uterine fibroid embolization, 75 to 97% for GI bleeding embolization, 60 to 92% for trauma embolization, 71 to 92% for tumor ablation, and 81 to 94% for angioplasty and stenting in peripheral arterial disease. With regard to knowledge of IR clinical roles, responses improved from 42 to 59% for outpatient clinic review of patients and having inpatient beds, 63-76% for direct patient consultation, and 43-60% for having regular ward rounds. The number of students who would consider a career in IR increased from 60 to 73%. CONCLUSION: Delivering an undergraduate IR curriculum increased the knowledge and understanding of various aspects of IR and also the general enthusiasm for pursuing this specialty as a future career choice.

Double Stent-Retriever Technique in Endovascular Treatment of Middle Cerebral Artery Saddle Embolus.

Ischemic stroke is a major public health problem worldwide, considered as the third most costly health condition in developed countries, with urgent reperfusion remaining the paramount goal for its treatment. In line with the results of recent randomized control trials, the introduction of stent retrievers was a major advancement in the treatment of stroke; however, interventionalists sometimes encounter thrombi not-retrievable by applying conventional techniques. In this article, we present a case treated by an innovative double-stent retrieval in Y-configuration that may potentially help other clinicians in similar situations.

Advances in endovascular treatment of acute ischaemic stroke.

Over the past decade, there have been rapid advancements in ischaemic stroke reperfusion treatments. However, clear clinical benefit is yet to be shown in large clinical trials. In this review, the major studies in different types of endovascular treatments including intra-arterial thrombolysis, aspiration devices, mechanical clot retrievers and the new stent retrievers are discussed. First-generation mechanical thrombectomy devices such as the MERCI Retriever (Stryker, Kalamazoo, MI, USA) and Penumbra aspiration device (Penumbra Inc., Alameda, CA, USA) demonstrated safety and higher rates of recanalisation in the MERCI and Penumbra Pivotal Stroke Trial; however, there was no significant improvement in clinical outcome. Second-generation endovascular stent retrieval devices Solitaire (ev3 Neurovascular, Irvine, CA, USA) and Trevo (Stryker) have shown promising results. In preliminary trials, SOLITAIRE with the Intention for Thrombectomy (SWIFT) and Thrombectomy Revascularization of Large Vessel Occlusions (TREVO), both showed rates of recanalisation close to 90% and significantly improved clinical outcomes compared with the MERCI study, but the recent landmark studies for endovascular treatment (Interventional Management of Stroke (IMS III), Mechanical Retrieval and Recanalisation of Stroke Clots Using Embolectomy (MR-RESCUE) and SYNTHESIS) did not show any clinical benefit from endovascular treatment compared with standard intravenous therapy. However, moving forward, the recent Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischaemic Stroke in the Netherlands (MR-CLEAN) study results have shown marked improvements in recanalisation, reperfusion and functional outcome in patients receiving endovascular treatment (97% using stent retrievers) within 6 h in addition to standard medical care. Overall, although evidence regarding the efficacy of endovascular treatment in acute stroke has been equivocal, recent publications of large multicentre randomised controlled trials indicate benefit of intra-arterial stent retriever reperfusion in patients selected by appropriate imaging and treated early by experienced operators, and it will likely remain an important adjunct to established medical treatment with intravenous tPA.

Advances in medical revascularisation treatments in acute ischemic stroke.

Urgent reperfusion of the ischaemic brain is the aim of stroke treatment and there has been ongoing research to find a drug that can promote vessel recanalisation more completely and with less side effects. In this review article, the major studies which have validated the use and safety of tPA are discussed. The safety and efficacy of other thrombolytic and anticoagulative agents such as tenecteplase, desmoteplase, ancrod, tirofiban, abciximab, eptifibatide, and argatroban are also reviewed. Tenecteplase and desmoteplase are both plasminogen activators with higher fibrin affinity and longer half-life compared to alteplase. They have shown greater reperfusion rates and improved functional outcomes in preliminary studies. Argatroban is a direct thrombin inhibitor used as an adjunct to intravenous tPA and showed higher rates of complete recanalisation in the ARTTS study with further studies which are now ongoing. Adjuvant thrombolysis techniques using transcranial ultrasound are also being investigated and have shown higher rates of complete recanalisation, for example, in the CLOTBUST study. Overall, development in medical therapies for stroke is important due to the ease of administration compared to endovascular treatments, and the new treatments such as tenecteplase, desmoteplase, and adjuvant sonothrombolysis are showing promising results and await further large-scale clinical trials.

Preparation of biodegradable nanoparticles of tri-block PLA-PEG-PLA copolymer and determination of factors controlling the particle size using artificial neural network.

The purpose of this study was to prepare nanoparticles made of tri-block poly(lactide)-poly(ethylene glycol)-poly (lactide) (PLA-PEG-PLA) with controlled size as drug carrier. Artificial neural networks (ANNs) were used to identify factors which influence particle size. In this way, PLA-PEG-PLA was synthesized and was made into nanoparticles by nanoprecipitation under different conditions. The copolymer and the resulting nanoparticles were characterized by various techniques such as proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, photon correlation spectroscopy and scanning electron microscopy. The developed model was assessed and found to be of high quality. The model was then used to survey the effects of processing factors including polymer concentration, amount of drug, solvent ratio and mixing rate on particle size of polymeric nanoparticles. It was observed that polymer concentration is the most affecting parameter on nanoparticle size distribution. The results demonstrate the potential of ANNs in modelling and identification of critical parameters effective on final particle size.

Preparation and characterization of tri-block poly(lactide)-poly(ethylene glycol)-poly(lactide) nanogels for controlled release of naltrexone.

Tri-block poly(lactide)-poly(ethylene glycol)-poly(lactide) (PLA-PEG-PLA) copolymers and related acrylated derivative were synthesized and used to prepare micelles and nanogels for controlled release of naltrexone. The resulting copolymers, micelles and nanogels were characterized by various techniques such as proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, fluorescence spectrometry, differential scanning calorimetry, photon correlation spectroscopy and scanning electron microscopy. The nanogels exhibited high encapsulation efficiency around 60% and excellent stability for long periods of time. The drug release profiles of micelles and nanogels were compared and it was found that the naltrexone loaded nanogels offered a steady and long-term release pattern for different periods of time up to 35 days, depending on the crosslinker concentration, compared to the micelles. The size of nanogels could be manipulated easily in the range of 128-200nm by variations in polymer concentration used in the nanogels preparation step. From the results obtained it can be concluded that PLA-PEG-PLA nanogels can be considered as a promising carrier for drug delivery purpose.

Particle swarm optimization on threshold exponential gain of stimulated Brillouin scattering in single mode fibers.

We implement a particle swarm optimization (PSO) algorithm to characterize stimulated Brillouin scattering phenomena in optical fibers. The explicit and strong dependence of the threshold exponential gain on the numerical aperture, the pump laser wavelength and the optical loss coefficient are presented. The proposed PSO model is also evaluated with the localized, nonfluctuating source model and the distributed (non-localized) fluctuating source model. Using our model, for fiber lengths from 1 km to 29 km, the calculated threshold exponential gain of stimulated Brillouin scattering is gradually decreased from 17.4 to 14.6 respectively. The theoretical results of Brillouin threshold power predicted by the proposed PSO model show a good agreement with the experimental results for different fiber lengths from 1 km to 12 km.