Alexis retractor efficacy in transthoracic thoracoscopically assisted discectomy for thoracic disc herniations.

PURPOSE: A transthoracic anterior or lateral approach for giant thoracic disc herniations is a complex operation which requires optimal exposure and maximal visualisation. Traditional metal rigid retractors may inflict significant skin trauma especially with prolonged operative use and limit the working angles of endoscopic instrumentation at depth. We pioneer the use of the Alexis retractor in transthoracic thoracoscopically assisted discectomy for the first time. METHODS: The authors describe and demonstrate the technical use of the Alexis retractor during operative cases. Patient positioning, clinical rationale and operative nuances are elucidated for readers to gain an appreciation of the transthoracic approach to thoracic disc herniations. RESULTS: The advantages of the Alexis retractor include minimally invasive circumferential flexible retraction, facilitation of bimanual instrument use, diminished risk of surgical site infections and reduced rib retraction leading to less postoperative pain. CONCLUSION: Use of the flexible and intuitive Alexis retractor maximises operative exposure and is an effective adjunct when performing complex transthoracic approaches for thoracic disc herniations.

CHIME-GP trial of online education for prescribing, pathology and imaging ordering in general practice - how did it bring about behaviour change?

BACKGROUND: There is a need for scalable clinician education in rational medication prescribing and rational ordering of pathology and imaging to help improve patient safety and enable more efficient utilisation of healthcare resources. Our wider study evaluated the effectiveness of a multifaceted education intervention for general practitioners (GPs) in rational prescribing and ordering of pathology and imaging tests, in the context of Australia's online patient-controlled health record system, My Health Record (MHR), and found evidence for measurable behaviour change in pathology ordering among participants who completed the educational activities. This current study explored the mechanisms of behaviour change brought about by the intervention, with a view to informing the development of similar interventions in the future. METHODS: This mixed methods investigation used self-reported questionnaires at baseline and post-education on MHR use and rational prescribing and test ordering. These were analysed using multi-level ordinal logistic regression models. Semi-structured interviews pre- and post-intervention were also conducted and were analysed thematically using the COM-B framework. RESULTS: Of the 106 GPs recruited into the study, 60 completed baseline and 37 completed post-education questionnaires. Nineteen participants were interviewed at baseline and completion. Analysis of questionnaires demonstrated a significant increase in confidence using MHR and in self-reported frequency of MHR use, post-education compared with baseline. There were also similar improvements in confidence across the cohort pre-post education in deprescribing, frequency of review of pathology ordering regimens and evidence-based imaging. The qualitative findings showed an increase in GPs' perceived capability with, and the use of MHR, at post-education compared with baseline. Participants saw the education as an opportunity for learning, for reinforcing what they already knew, and for motivating change of behaviour in increasing their utilisation of MHR, and ordering fewer unnecessary tests and prescriptions. CONCLUSIONS: Our education intervention appeared to provide its effects through providing opportunity, increasing capability and enhancing motivation to increase MHR knowledge and usage, as well as rational prescribing and test ordering behaviour. There were overlapping effects of skills acquisition and confidence across intervention arms, which may have contributed to wider changes in behaviour than the specific topic area addressed in the education. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12620000010998) (09/01/2020).

Textbook outcomes after oesophagectomy: a single-centre observational study.

BACKGROUND: Textbook outcomes is a composite quality assurance tool assessing the ideal perioperative and postoperative course as a unified measure. Currently, its definition and application in the context of oesophagectomy in Australia is unknown. The aim of this study was to assess the textbook outcomes after oesophagectomy in a single referral centre of Australia and investigate the association between textbook outcomes and patient, tumour, and treatment characteristics. METHODS: An observational study was retrospectively performed on patients undergoing open, laparoscopic, or hybrid oesophagectomy between January 2010 and December 2019 in a single cancer referral centre. A textbook outcome was defined as the fulfillment of 10 criteria: R0 resection, retrieval of at least 15 lymph nodes, no intraoperative complications, no postoperative complications greater than Clavien-Dindo grade III, no anastomotic leak, no readmission to the ICU, no hospital stay beyond 21 days, no mortality within 90 days, no readmission related to the surgical procedure within 30 days from admission and no reintervention related to the surgical procedure. The proportion of patients who met each criterion for textbook outcome was calculated and compared. Selected patient-related parameters (age, gender, BMI, ASA score, CCI score), tumour-related factors (tumour location, tumour histology, AJCC clinical T and N stage and treatment-related factor [neoadjuvant chemotherapy and surgical approach]) were assessed. Disease recurrence and one year survival were also evaluated. RESULTS: 110 patients who underwent oesophagectomy were included. The overall textbook outcome rate was 24%. The difference in rates across the years was not statistically significant. The most achieved textbook outcome parameters were 'no mortality in 90 days' (96%) and 'R0 resection' (89%). The least frequently met textbook outcome parameter was 'no severe postoperative complications' (58%), followed by 'no hospital stays over 21 days' (61%). No significant association was found between patient, tumour and treatment characteristics and the rate of textbook outcome. Tumour recurrence rate and overall long term survival was similar between textbook outcome and non-textbook outcome groups. Patients with R0 resection, no intraoperative complication and a hospital stay less than 21 days had reduced mortality rates. CONCLUSIONS: Textbook outcome is a clinically relevant indicator and was achieved in 24% of patients. Severe complications and a prolonged hospital stay were the key criteria that limited the achievement of a textbook outcome. These findings provide meticulous evaluation of oesophagectomy perioperative care and provide a direction for the utilisation of this concept in identifying and improving surgical and oncological care across multiple healthcare levels.

Generally Applicable Holographic Torque Measurement for Optically Trapped Particles.

We present a method to measure the optical torque applied to particles of arbitrary shape such as micrometer-sized micro-organisms or cells held in an optical trap, inferred from the change of angular momentum of light induced by the particle. All torque components can be determined from a single interference pattern recorded by a camera in the back focal plane of a high-NA condenser lens provided that most of the scattered light is collected. We derive explicit expressions mapping the measured complex field in this plane to the torque components. The required phase is retrieved by an iterative algorithm, using the known position of the optical traps as constraints. The torque pertaining to individual particles is accessible, as well as separate spin or orbital parts of the total torque.

Quantum Nonlocal Aberration Cancellation.

Phase distortions, or aberrations, can negatively influence the performance of an optical imaging system. Through the use of position-momentum entangled photons, we nonlocally correct for aberrations in one photon's optical path by intentionally introducing the complementary aberrations in the optical path of the other photon. In particular, we demonstrate the simultaneous nonlocal cancellation of aberrations that are of both even and odd order in the photons' transverse degrees of freedom. We also demonstrate a potential application of this technique by nonlocally canceling the effect of defocus in a quantum imaging experiment and thereby recover the original spatial resolution.

Mechanical chiral resolution.

Mechanical interactions of chiral objects with their environment are well-established at the macroscale, like a propeller on a plane or a rudder on a boat. At the colloidal scale and smaller, however, such interactions are often not considered or deemed irrelevant due to Brownian motion. As we will show in this tutorial review, mechanical interactions do have significant effects on chiral objects at all scales, and can be induced using shearing surfaces, collisions with walls or repetitive microstructures, fluid flows, or by applying electrical or optical forces. Achieving chiral resolution by mechanical means is very promising in the field of soft matter and to industry, but has not received much attention so far.

Relativistic Electron Vortices.

The desire to push recent experiments on electron vortices to higher energies leads to some theoretical difficulties. In particular the simple and very successful picture of phase vortices of vortex charge ℓ associated with ℓℏ units of orbital angular momentum per electron is challenged by the facts that (i) the spin and orbital angular momentum are not separately conserved for a Dirac electron, which suggests that the existence of a spin-orbit coupling will complicate matters, and (ii) that the velocity of a Dirac electron is not simply the gradient of a phase as it is in the Schrödinger theory suggesting that, perhaps, electron vortices might not exist at a fundamental level. We resolve these difficulties by showing that electron vortices do indeed exist in the relativistic theory and show that the charge of such a vortex is simply related to a conserved orbital part of the total angular momentum, closely related to the familiar situation for the orbital angular momentum of a photon.

Will a Decaying Atom Feel a Friction Force?

We show how a simple calculation leads to the surprising result that an excited two-level atom moving through a vacuum sees a tiny friction force of first order in v/c. At first sight this seems to be in obvious contradiction to other calculations showing that the interaction with the vacuum does not change the velocity of an atom. It is even more surprising that this change in the atom's momentum turns out to be a necessary result of energy and momentum conservation in special relativity.

Surgery for limited-stage small-cell lung cancer.

BACKGROUND: Current treatment guidelines for limited-stage small-cell lung cancer (SCLC) recommend concomitant platinum-based chemo-radiotherapy plus prophylactic cranial irradiation, based on the premise that SCLC disseminates early, and is chemosensitive. However, although there is usually a favourable initial response, relapse is common and the cure rate for limited-stage SCLC remains relatively poor. Some recent clinical practice guidelines have recommended surgery for stage 1 (limited) SCLC followed by adjuvant chemotherapy, but this recommendation is largely based on the findings of observational studies. OBJECTIVES: To determine whether, in patients with limited-stage SCLC, surgical resection of cancer improves overall survival and treatment-related deaths compared with radiotherapy or chemotherapy, or a combination of radiotherapy and chemotherapy, or best supportive care. SEARCH METHODS: We performed searches on CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science up to 11 January 2017. We handsearched review articles, clinical trial registries, and reference lists of retrieved articles. SELECTION CRITERIA: We included randomised controlled trials (RCTs) with adults diagnosed with limited-stage SCLC, confirmed by cytology or histology, and radiological assessment, considered medically suitable for resection and radical radiotherapy, which randomised participants to surgery versus any other intervention. DATA COLLECTION AND ANALYSIS: We imported studies identified by the search into a reference manager database. We retrieved the full-text version of relevant studies, and two review authors independently extracted data. The primary outcome measures were overall survival and treatment-related deaths; and secondary outcome measures included loco-regional progression, quality of life, and adverse events. MAIN RESULTS: We included three trials with 330 participants. We judged the quality of the evidence as very low for all the outcomes. The quality of the data was limited by the lack of complete outcome reporting, unclear risk of bias in the methods in which the studies were conducted, and the age of the studies (> 20 years). The methods of cancer staging and types of surgical procedures, which do not reflect current practice, reduced our confidence in the estimation of the effect.Two studies compared surgery to radiation therapy, and in one study chemotherapy was administered to both arms. One study administered initial chemotherapy, then responders were randomised to surgery versus control; following, both groups underwent chest and whole brain irradiation.Due to the clinical heterogeneity of the trials, we were unable to pool results for meta-analysis.All three studies reported overall survival. One study reported a mean overall survival of 199 days in the surgical arm, compared to 300 days in the radiotherapy arm (P = 0.04). One study reported overall survival as 4% in the surgical arm, compared to 10% in the radiotherapy arm at two years. Conversely, one study reported overall survival at two years as 52% in the surgical arm, compared to 18% in the radiotherapy arm. However this difference was not statistically significant (P = 0.12).One study reported early postoperative mortality as 7% for the surgical arm, compared to 0% mortality in the radiotherapy arm. One study reported the difference in mean degree of dyspnoea as -1.2 comparing surgical intervention to radiotherapy, indicating that participants undergoing radiotherapy are likely to experience more dyspnoea. This was measured using a non-validated scale. AUTHORS' CONCLUSIONS: Evidence from currently available RCTs does not support a role for surgical resection in the management of limited-stage small-cell lung cancer; however our conclusions are limited by the quality of the available evidence and the lack of contemporary data. The results of the trials included in this review may not be generalisable to patients with clinical stage 1 small-cell lung cancer carefully staged using contemporary staging methods. Although some guidelines currently recommend surgical resection in clinical stage 1 small-cell lung cancer, prospective randomised controlled trials are needed to determine if there is any benefit in terms of short- and long-term mortality and quality of life compared with chemo-radiotherapy alone.

A mixed-methods feasibility study of routinely weighing patients in general practice to aid weight management.

BACKGROUND: The optimal role of general practice in population weight management remains unclear. The aim of this mixed-methods study was to test the feasibility of routinely weighing all adult patients attending their general practice as an intervention to aid weight management in clinical practice. METHODS: Consenting patients in six general practices were weighed at each presentation over a 12-month period. Data were analysed using linear mixed growth models. Participants' interviews at the completion of the study were thematically analysed. RESULTS: The overall weight loss in patients who completed the study (n = 217) was 0.51 kg (P = 0.26; not significant); in patients who were obese (n = 106) there was a greater weight loss of 1.79 kg (P = 0.04). Patients were receptive to the intervention; however, there was disruption to clinical workflow. DISCUSSION: Routinely weighing adult patients in general practice is feasible, requires resources and may be associated with weight loss in patients who are obese. Further research is required to inform support for implementation within practices.

The role of sponge-bacteria interactions: the sponge Aplysilla rosea challenged by its associated bacterium Streptomyces ACT-52A in a controlled aquarium system.

Sponge-associated bacteria play a critical role in sponge biology, metabolism and ecology, but how they interact with their host sponges and the role of these interactions are poorly understood. This study investigated the role of the interaction between the sponge Aplysilla rosea and its associated actinobacterium, Streptomyces ACT-52A, in modifying sponge microbial diversity, metabolite profile and bioactivity. A recently developed experimental approach that exposes sponges to bacteria of interest in a controlled aquarium system was improved by including the capture and analysis of secreted metabolites by the addition of an absorbent resin in the seawater. In a series of controlled aquaria, A. rosea was exposed to Streptomyces ACT-52A at 106 cfu/ml and monitored for up to 360 h. Shifts in microbial communities associated with the sponges occurred within 24 to 48 h after bacterial exposure and continued until 360 h, as revealed by TRFLP. The metabolite profiles of sponge tissues also changed substantially as the microbial community shifted. Control sponges (without added bacteria) and Streptomyces ACT-52A-exposed sponges released different metabolites into the seawater that was captured by the resin. The antibacterial activity of compounds collected from the seawater increased at 96 and 360 h of exposure for the treated sponges compared to the control group due to new compounds being produced and released. Increased antibacterial activity of metabolites from treated sponge tissue was observed only at 360 h, whereas that of control sponge tissue remained unchanged. The results demonstrate that the interaction between sponges and their associated bacteria plays an important role in regulating secondary metabolite production.

Positive Clinical Outcomes Are Synergistic With Positive Educational Outcomes When Using Telehealth Consulting in General Practice: A Mixed-Methods Study.

BACKGROUND: The use of telehealth technology to enable real-time consultations between patients and specialist services (to whom travel may be an impediment to the patient's care) has recently been encouraged in Australia through financial incentives. However, the uptake has been both fragmented and inconsistent. The potential benefits for patients include access to a broader range of specialist referral services, cost and time saving, and more rapid access to specialist services and a continuum of care through the triangulation of interaction between patient, primary health care providers (general practitioners and nurses), and specialists. Enhanced broadband connectivity and higher-grade encryption present an opportunity to trial the use of telehealth consulting as an intrinsic element of medical education for both medical students and doctors-in-training within rural practices and Aboriginal Medical Services. OBJECTIVE: This paper discusses the reported, and varied, benefits of telehealth consulting arising from a multisite trial in New South Wales, Australia. The purpose of this study is to encourage the use of selected telehealth consultations between patients in a primary care setting with a specialist service as an integral aspect of medical education. METHODS: The trial closely followed the protocol developed for this complex and multiaspect intervention. This paper discusses one aspect of the research protocol--using telehealth consultations for medical education--in detail. RESULTS: Qualitative and quantitative analyses were conducted. In the quantitative analysis, free-text comments were made on aspects of Telehealth Consulting for the patient, concerning the quality of the interactions, and the time and cost saving, and also on the leaning opportunities. Students commented that their involvement enhanced their learning. All respondents agreed or strongly agreed that that the interpersonal aspects were satisfactory, with some brief comments supporting their views. In the analysis of the qualitative data, five themes emerged from the analyses concerning the educational benefits of Telehealth Consulting for different levels of learners, while three themes were identified concerning clinical benefits. CONCLUSIONS: The results demonstrated strong synergies between the learning derived from the telehealth consulting and the clinical benefits to the patient and clinicians involved.

Video-assisted thoracic surgery for left upper lobectomy for complex lesions: how to extend the indication with optimal safety?

The feasibility of extending the VATS approach to locally advanced NSCLC has been described with good clinical outcome. These complex resections are still technically challenging and patient safety must remain the highest priority. In this article, we describe our routine VATS approach for left upper lobectomy in proximal, locally advanced lesions. Both surgical and anaesthesiology teams are trained during simulation sessions to respond rapidly in case of urgent thoracotomy. Encircling arterial and venous vessels allow control of inadvertent bleeding during difficult dissection. Also, whenever needed the double vessel control technique is a time saver waiting for conversion to thoracotomy.

Experimental implementation of a quantum optical state comparison amplifier.

We present an experimental demonstration of a practical nondeterministic quantum optical amplification scheme that employs two mature technologies, state comparison and photon subtraction, to achieve amplification of known sets of coherent states with high fidelity. The amplifier uses coherent states as a resource rather than single photons, which allows for a relatively simple light source, such as a diode laser, providing an increased rate of amplification. The amplifier is not restricted to low amplitude states. With respect to the two key parameters, fidelity and the amplified state production rate, we demonstrate significant improvements over previous experimental implementations, without the requirement of complex photonic components. Such a system may form the basis of trusted quantum repeaters in nonentanglement-based quantum communications systems with known phase alphabets, such as quantum key distribution or quantum digital signatures.

Respiratory-gated (4D) FDG-PET detects tumour and normal lung response after stereotactic radiotherapy for pulmonary metastases.

BACKGROUND: Response assessment after stereotactic ablative body radiotherapy (SABR) in lung can be confounded by radiation-induced inflammation, fibrosis and subsequent alteration of tumour motion. The purpose of this prospective pilot study was to evaluate the utility of four-dimensional (4D) FDG-PET/CT for post-SABR tumour and normal lung response assessment in pulmonary oligometastases. MATERIAL AND METHODS: Patients enrolled from February 2010 to December 2011 in this prospective ethics approved study had 1-2 pulmonary metastases on staging FDG-PET. Serial contemporaneous 3D and 4D FDG-PET/CT scans were performed at baseline, 14 days and 70 days after a single fraction of 26 Gy SABR. Tumour response was evaluated in 3D and 4D using SUVmax, RECIST and PERCIST criteria. Normal lung radiotoxicity was evaluated using SUVmean within 0-2 Gy, 2-5 Gy, 5-10 Gy, 10-20 Gy and 20 + Gy isodose volumes. RESULTS: In total, 17 patients were enrolled of which seven were ineligible due to interval progression from staging PET to baseline 4D-PET. The mean time between scans was 62 days. At a median follow-up of 16 months, 10 patients with 13 metastases received SABR, with no patient having local progression. The vector of tumour motion was larger in patients with discordant 3D and 4D PET PERCIST response (p < 0.01), with a mean (± SEM) motion of 10.5 mm (± 0.96 mm) versus 6.14 mm (± 0.81 mm) in those patients with concordant 3D and 4D response. Surrounding normal lung FDG uptake at 70 days was strongly correlated to delivered radiation dose (r(2) = 0.99, p < 0.01), with significant elevations across all dose levels (p ≤ 0.05), except the < 2 Gy volume (p = 0.30). CONCLUSIONS: We demonstrate high rates of interval progression between staging PET scans in patients with oligometastases. We found that tumour response on conventional 3D PET is not concordant with 4D PET for tumours with large motion. Normal lung metabolic uptake is strongly dose dependent after SABR, a novel finding that should be further validated.

Development of an Australian practice-based research network as a community of practice.

There are many aspects of the communities of practice (CoP) framework that are applicable to the development of a practice-based research network (PBRN), where the focus is upon building primary health-care workers' research capacity and research questions. However, there is limited literature focussed on the application of CoP principles applied to research capacity building in Australia. The purpose of this paper is to demonstrate, through a case study, how a developing PBRN, the Illawarra and Southern Practice Research Network, successfully applied the theoretical foundation of CoP to develop a PBRN in a time- and resource-limited context.

Optical angular momentum in a rotating frame.

It is well established that light carrying orbital angular momentum (OAM) can be used to induce a mechanical torque causing an object to spin. We consider the complementary scenario: will an observer spinning relative to the beam axis measure a change in OAM as a result of their rotational velocity? Remarkably, although a linear Doppler shift changes the linear momentum of a photon, the angular Doppler shift induces no change in the angular momentum. Further, we examine the rotational Doppler shift in frequency imparted to the incident light due to the relative motion of the beam with respect to the observer and consider what must happen to the measured wavelength if the speed of light c is to remain constant. We show specifically that the OAM of the incident beam is not affected by the rotating observer and that the measured wavelength is shifted by a factor equal and opposite to that of the frequency shift induced by the rotational Doppler effect.

Is the angular momentum of an electron conserved in a uniform magnetic field?

We show that an electron moving in a uniform magnetic field possesses a time-varying "diamagnetic" angular momentum. Surprisingly this means that the kinetic angular momentum of the electron may vary with time, despite the rotational symmetry of the system. This apparent violation of angular momentum conservation is resolved by including the angular momentum of the surrounding fields.

Optical activity in the scattering of structured light.

We observe that optical activity in light scattering can be probed using types of illuminating light other than single plane (or quasi plane) waves and that this introduces new possibilities for the study of molecules and atoms. We demonstrate this explicitly for natural Rayleigh optical activity which, we suggest, could be exploited as a new form of spectroscopy for chiral molecules through the use of illuminating light comprised of two plane waves that are counter propagating.