Primary Operator Research Articles

Prediction of Left Atrial Appendage occluder size based on 3D printed models

Abstract Funding Acknowledgements Type of funding sources: None. Background occlusion of the left atrial appendage (LAA) is an established method in the prevention of thromboembolic complications in patients with atrial fibrillation and high bleeding risk. There is a huge anatomical variability of LAA and choosing the right type and size of the occluder may be challenging and result in a time-consuming procedure with repeated repositioning of the selected device, or a need to use another device. These aspects may lead to a prolonged or more aggressive manipulation resulting in periprocedural complications and a suboptimal result. The current technology of 3D printing allows us to obtain a real model of the LAA and to simulate the course of implantation. Purpose in a post-hoc analysis to compare occluder sizes predicted as optimal by simulation on a 3D-printed LAA model to actually implanted LAA occluders, and analyse potential benefits of such simulations. Methods We analysed 32 consecutive patients after a TEE-guided implantation of the Amulet occluder in whom a CT cardiac scan had been performed prior to the procedure. Based on the CT, an LAA 3D model was printed out post-hoc for each patient. Two experienced operators blinded to the procedural results simulated the implantation ex-vivo and agreed on the most appropriate size of the occluder to fit in the LAA. If the simulation-based size matched the size of the primary operator`s choice and this occluder was actually implanted („intention-to-implant and implanted"), the match was considered positive; otherwise it was negative. The number of positive and negative matches and corresponding procedural characteristics were analysed. Results The positive match was found in 9 (28.1%) cases. Out of 23 (71.9%) negative matches, there were 11 (47.8%) implantations using a bigger-than-simulated and 12 (52.2%) smaller-than-simulated occluder; in 2 (8.7%) cases the actually implanted occluder matched the simulated size but was a 2nd -choice occluder. In positive-match cases compared to negative-match cases, there was a statistically significant less need for an occluder reposition (median 0.0 vs 1.0, p = 0,02), and a trend to a shorter procedural time (average 66.7+ 13.3 min vs 85.2 + 32.8 min, p = 0.112) and less contrast agent consumption (average 188.9 + 67.9ml vs 220.9 + 112.4ml, p = 0.43). Conclusion The preliminary results of our study suggest that a CT-based 3D modelling of the LAA shape and simulating the LAA occlusion procedure ex-vivo have a potential to become useful tools to reduce procedural time and complications. Our results might serve as a rational for a prospective study. Abstract Figure. Occluder in the 3D model

A Novel Catheterization Laboratory Radiation Shielding System: Results of Pre-Clinical Testing

BackgroundThis pre-clinical study evaluated the efficacy of a novel shielding system to reduce scatter radiation in the cardiac catheterization laboratory. MethodsUsing a scatter radiation phantom in a standard cardiac catheterization laboratory, a radiation physicist recorded radiation measurements at 20 reference points on the operator side of the table. Measurements were made with fluoroscopy and cine with the C-arm in the posterior-anterior (PA) and 40 degrees left anterior oblique (LAO) orientations. Scatter radiation doses were compared with and without use of the shielding system. ResultsUse of the shielding system was associated with >94.2% reduction in scatter radiation across all reference points in the PA and LAO projections with fluoroscopy and cine. With the shielding system, dose reductions at the location of the primary operator ranged from 97.8% to 99.8%. At locations of maximum scatter radiation, use of the shielding system resulted in dose reductions ranging from 97.8% to 99.8% with fluoroscopy and from 97.9% to 99.8% with cine. ConclusionsIn this pre-clinical study, a novel radiation shielding system was observed to dramatically reduce scatter radiation doses. Based on these results, clinical testing is warranted to determine whether the shielding system will enable operators and staff to perform interventional procedures with less radiation exposure that may obviate the need to wear standard lead apparel. Indexing wordsRadiation safety; occupational health; occupational hazard.

Nationwide Trends in Tube-Related Genitourinary Interventions for Medicare Beneficiaries.

To evaluate national trends in tube-related genitourinary interventions, with specific attention to primary operator specialty. Using a 5% national sample of Medicare claims data from 2005 to 2015, all claims associated with nephrostomy tube, nephro-ureteral tube, and ureteral stent placement and exchange were identified. The annual volume of the nine billable procedures were analyzed to evaluate trends in the number of procedures performed and primary operator specialty over time. The Charleston Comorbidity Index (CCI) was used to evaluate patient comorbidities and to determine differences in patient populations treated by interventional radiologists and urologists. The total volume of tube-related genitourinary interventions has increased over the course of the study period, representing 455.0 services per 100,000 Medicare Fee-for-Service beneficiaries in 2005 to 607.2 services in 2015, an increase of 33.4%. Interventional radiologists performed the majority of all procedures in all procedure types and for each year (>90%) with the exception of nephro-ureteral catheter placement or ureteral stent placement, for which urologists performed the overwhelming majority of procedures each year (>85%). Interventional radiologists performed 63% of their total number of procedures on patients with a CCI= 3 or higher, and urologists performed 42% of their total number of procedures on patients with a CCI= 3 or higher (P < .01). Tube-related genitourinary interventions have demonstrated persistent growth over the 2005 to 2015 decade. Interventional radiologists are the dominant providers for the majority of these interventions compared with urologists while delivering care to a patient population with a higher number of comorbidities.

504 Can Measuring Heart Rate Variability in The Operating Surgeon Provide Insight into Intra-Operative Stress? A Literature Review and Direction for Research

Abstract Introduction Stress affects the internal environment of the operating surgeon. Examining ways to mitigate this could prove important to the health of both surgeon, and patients. Heart rate variability (HRV) is emerging as a novel, validated measure of autonomic nervous system (ANS) function with developing accessible and non-invasive technologies. HRV parameters correlate to ANS function and can be used to measure responses to various stimuli. Method A search strategy was developed to identify 23 articles that matched inclusion criteria. These included data collected intra-operatively with ambulatory monitoring, in simulated settings and one systematic review. Results Several studies found increased sympathetic response in the operating surgeon – which correlates with subjective reporting of stress. Some studies compared variables; one study suggested that laparoscopic colorectal surgery caused higher mental strain than open, while another suggested higher stress in surgeons while teaching compared to when primary operator. There have been no comparative trials using HRV in surgeons. Conclusions We present a review of the growing literature regarding HRV measurement in surgeons. This novel tool is a promising avenue to provide psychophysiological insight into the operating surgeon. This could guide future research into optimising the theatre environment for intra-operative performance using controlled or in-situ design.

617 Does Wearing Enhanced Personal Protective Equipment (PPE) In Theatre Increase Surgeon Workload and Patient Morbidity?

IntroductionDelivery of surgical services during the Covid-19 pandemic has required the use of enhanced PPE in the operating theatre. We sought to evaluate the impact of this change on surgeon workload and intraoperative patient outcomes.MethodSurgeons performing as primary operator completed an online procedure-specific questionnaire on workload ratings for each operative case, using an extension of the validated Surgeon Task Load Index (SURG-TLX) tool (reported on a 20-point scale), together with operative details. Local approval was obtained at individual sites. Data was analysed in Stata SE v16.Results118 responses (17 surgeons, 7 specialties) were collected from June to September 2020. 77.1% used enhanced PPE. There was no association between enhanced PPE use and overall workload (p = 0.151) as measured with SURG-TLX, although surgeons wearing enhanced PPE commonly reported finding individual procedures harder than expected (37% vs 0%, p < 0.001). Communication was rated worse when using enhanced PPE use (MD -4.38, 95%CI -6.74 to 02.03; p < 0.001). There was no association between enhanced PPE use and intraoperative complications (p = 0.745).ConclusionsThe use of enhanced PPE is not associated with complications or increased surgeon workload assessed by SURG-TLX. It is, however, associated with difficulty in communicating, and subjectively experiencing more procedural challenge than anticipated.

Instability of complex CFTs with operators in the principal series

We prove the instability of d-dimensional conformal field theories (CFTs) having in the operator-product expansion of two fundamental fields a primary operator of scaling dimension h = frac{d}{2} + i r, with non-vanishing r ∈ ℝ. From an AdS/CFT point of view, this corresponds to a well-known tachyonic instability, associated to a violation of the Breitenlohner-Freedman bound in AdSd+1; we derive it here directly for generic d-dimensional CFTs that can be obtained as limits of multiscalar quantum field theories, by applying the harmonic analysis for the Euclidean conformal group to perturbations of the conformal solution in the two-particle irreducible (2PI) effective action. Some explicit examples are discussed, such as melonic tensor models and the biscalar fishnet model.

Students opinion about E-Learning in a Master course in Interventional Radiology: a survey among participants

AIM: To evaluate the opinion of students about Tele-education in a post-graduate University Master in Interventional Radiology.&#x0D; METHODS: The core curriculum of the Master is divided into 3 e-Learning modules and 2 e-Learning plus Hands-on Training modules. E-Learning is delivered through a webinar platform that allows to perform a synchronous training providing real-time lectures that are recorded for streaming on a dedicated website. The Hands-on Training is provided on site, assisting interventional radiologists in interventional procedures on patients. An online survey of 12 questions has been prepared to determine the quality of training. Students indicated their level of agreement regarding the impact of eLearning and Hands on Training using a 5-point scale. The mean score of the level of agreement was calculated.&#x0D; RESULTS: The series include 16 participants. The 62.5% work in a public non-academic Hospital and 80% have already performed 300 interventional procedures as primary operator.&#x0D; The main advantage of the eLearning module was considered the capability to facilitate the attendance to lectures (68.8%) followed by the low cost training (18.8%), with a good agreement between participants. No students scored the statements as less than 3. The Master fulfilled the learning expectations in 81.3% of cases with a good agreement between participants.&#x0D; CONCLUSIONS: The participants were highly satisfied and would recommend the Master to other colleagues. The blended type of education of our Master received high appreciation and could be a model to be follow in the future, also in IR.

Australian general surgical trainee experience with inguinal hernia surgery: a review of international training programmes and the learning curve.

There are no publications addressing the level of experience Australian surgical trainees achieve in inguinal hernia surgery. Internationally, some training boards have set minimum competency requirements, but this is not true in Australia. The longer learning curve for laparoscopic inguinal hernia repairs (LIHRs) compared to open inguinal hernia repairs (OIHRs) has placed greater demands on trainees. Logbook data on OIHR and LIHR for Australian surgical trainees who graduated as fellows between 2013 and 2018 were obtained. A literature review was performed to analyse international published logbook numbers for surgical trainees from the past decade. International training board requirements, estimations of the learning curve and hernia society guidelines for each procedure were reviewed. In total, 7946 operations were recorded from 58 trainees. On average 49.2 OIHRs (range 13-101), 21.5 LIHRs (range 1-94) and 71.1 inguinal hernia repairs overall (range 25-129) were performed during training. The European Hernia Society recommends that at least 30-50 of each procedure be performed during training. The learning curves for LIHRs (50-100 procedures) have been shown to be longer than for OIHRs (40-64 procedures). Australian general surgical trainees are achieving adequate primary operator logbook numbers for OIHRs but are not completing the required number of LIHRs. The tailored approach to inguinal hernia repair requires skill in both open and laparoscopic repairs. This may not be possible with the current training structure in Australia.

Operative experience in essential emergency general surgery procedures: is autonomy achievable during surgical training?

Readiness for practice is an ongoing concern in surgery. Surgeons who have completed general surgery training are expected to be proficient in performing common emergency procedures. The aim of this study was to assess the experience and autonomy of general surgery trainees in New Zealand in 10 emergency general surgery procedures, and identify factors associated with reaching primary operator (PO) thresholds. Operative logbook data from all New Zealand general surgery trainees from 2013 to 2017 were analysed. Data for 10 emergency general surgery procedures were extracted to determine PO and autonomous PO (mentor not scrubbed) rates. A threshold of 70% for PO and APO rates was used to define two levels of proficiency. A total of 120 trainees performed 40 865 included procedures. Trainees met the PO threshold for all procedures by Surgical Education and Training (SET) 5. The APO threshold was met for three of 10 procedures (appendicectomy, drainage of perianal abscess and perforated peptic ulcer repair). Final APO rates for the other procedures ranged from 18% to 58%. On multivariate analysis, SET year and case volume were associated with increased odds of meeting the PO and APO thresholds. Female trainees were less likely to reach the PO and APO thresholds for three of 10 and four of 10 procedures, respectively. Trainees had increasing PO and autonomous PO rates over the course of their training. Graduating New Zealand general surgeons likely have sufficient operative experience in emergency general surgery procedures. However, rates of autonomy are lower, and further research is needed to determine whether this affects readiness for independent practice.

Impact of operator experience and volume on outcomes after complete repair for tetralogy of Fallot.

The aim of this study was to assess the impact of individual operator experience on outcomes after complete repair for tetralogy of Fallot. This is a retrospective cohort study. Consecutive patients who underwent TOF repair at a single institution were included and compared according to whether the primary operator was an experienced, high-volume operator (defined as an operator who performed at least 20 surgical procedures for congenital heart disease defined as complex by the Risk Adjustment for Congenital Heart Surgery classification per year for at least 3 consecutive years). The primary outcome was defined as a composite of death, or reintervention, or significant annular peak gradient, or significant pulmonary regurgitation. Multivariable logistic regression and Cox proportional-hazards model analyses were used to assess the relationships between operator experience and outcomes. From January 2012 to December 2017, a total of 1760 patients with primary diagnosis of TOF underwent TOF repair by 37 operators. Of these, 5 operators (13.5%) were considered experienced, and 32 (86.5%) were considered less experienced. Complete follow-up data were available for 1728 complete repair for TOF patients with a median follow-up duration of 49 months; in 611 patients (35.4%), the surgery was performed by experienced operators, and in 1117 patients (64.6%), the surgery was performed by less experienced operators. Adjusted risks for the primary outcome and significant pulmonary regurgitation were lower for patients who were treated by experienced operators, both at discharge [adjusted odds ratio 0.67, 95% confidence interval (CI) 0.50-0.90; adjusted odds ratio 0.54, 95% CI 0.37-0.78, respectively] and at follow-up (adjusted hazard ratio 0.82, 95% CI 0.68-0.97; adjusted hazard ratio 0.70, 95% CI 0.56-0.87, respectively). The trend for the primary outcome during follow-up remained unchanged, even in most subgroups. Increased surgeon experience is associated with improved risk-adjusted outcomes. These results have potentially important implications for individual training, quality improvement and hospital programmes in the context of complete repair for TOF. http://www.chictr.org.cn number, ChiCTR2000033234.

The quasi-particle picture and its breakdown after local quenches: mutual information, negativity, and reflected entropy

We study the dynamics of (Rényi) mutual information, logarithmic negativity, and (Rényi) reflected entropy after exciting the ground state by a local operator. Together with recent results from ref. [1], we are able to conjecture a close-knit structure between the three quantities that emerges in states excited above the vacuum, including both local and global quantum quenches. This structure intimately depends on the chaoticity of the theory i.e. there exist distinct sets of equivalences for integrable and chaotic theories. For rational conformal field theories (RCFT), we find all quantities to compute the quantum dimension of the primary operator inserted. In contrast, we find the correlation measures to grow (logarithmically) without bound in all c > 1 conformal field theories with a finite twist gap. In comparing the calculations in the two classes of theories, we are able to identify the dynamical mechanism for the breakdown of the quasi-particle picture in 2D conformal field theories. Intriguingly, we also find preliminary evidence that our general lessons apply to quantum systems considerably distinct from conformal field theories, such as integrable and chaotic spin chains, suggesting a universality of entanglement dynamics in non-equilibrium systems.

The Impact of COVID-19 on International Tourism Flows to Italy: Evidence from Mobile Phone Data

This paper analyses the response to the COVID-19 pandemic of inbound tourism to Italy looking at variation across countries and across provinces. To this end, it uses weekly data on the number of foreign visitors in Italy from January 2019 until February 2021, as provided by a primary mobile phone operator. We document a very robust negative relation at province level between local epidemiological conditions and the inflow of foreign travellers. Moreover, provinces with a historically higher share of art tourism, and those that used to be ‘hotel intensive’ were hit the most during the pandemic, while provinces with a more prevalent orientation towards business tourism proved to be more resilient. Entry restrictions with varying degrees of strictness played a key role in explaining cross-country patterns. After controlling for these restrictions, we observed that the travellers that could arrive by their own, private, means of transportation decreased proportionally less. Overall, this evidence emphasises that contagion risk considerations played a significant role in shaping international tourism patterns during the pandemic.

The Impact of Covid-19 on International Tourism Flows to Italy: Evidence from Mobile Phone Data

This paper analyses the response to the COVID-19 pandemic of inbound tourism to Italy looking at variation across countries and across provinces. To this end, it uses weekly data on the number of foreign visitors in Italy from January 2019 until February 2021, as provided by a primary mobile phone operator. We document a very robust negative relation at province level between local epidemiological conditions and the inflow of foreign travellers. Moreover, provinces with a historically higher share of art tourism, and those that used to be ‘hotel intensive’ were hit the most during the pandemic, while provinces with a more prevalent orientation towards business tourism proved to be more resilient. Entry restrictions with varying degrees of strictness played a key role in explaining cross-country patterns. After controlling for these restrictions, we observed that the travellers that could arrive by their own, private, means of transportation decreased proportionally less. Overall, this evidence emphasises that contagion risk considerations played a significant role in shaping international tourism patterns during the pandemic.

The Impact of Experience on Fluoroscopy Time for Peripherally Inserted Central Venous Catheters in a Pediatric Population: A Retrospective Review

Background: &#x0D; It is established that radiation exposure carries a risk for children. The best approach is to use the As Low As Reasonably Achievable (ALARA) principle for medical procedures. Peripherally inserted central venous catheter (PICC) placements expose children to a variable amount of radiation. The purpose of this study was to try and determine if procedural experience plays a part in reducing radiation exposure during PICC placements. &#x0D; &#x0D; Methods: &#x0D; Pediatric PICC placements by a junior attending pediatric interventional radiologist (JrIR) were reviewed, analyzing for a primary end point of fluoroscopy time (FT). These values were also compared to those of trainees and of a senior pediatric interventional radiologist (SrIR) with 15+ years of experience. Statistical analysis included the Mann-Whitney U test. P values &lt; .05 were considered significant. &#x0D; &#x0D; Results: &#x0D; FT for 685 trainee, 459 JrIR, and 425 SrIR PICC placements were analyzed. No statistically significant decreasing trend in FT was noted for either the JrIR or SrIR over the course of the study period. Trainees required significantly more FT than the JrIR (Trainees = .80 min, JrIR = .70 min, P = .004) or the SrIR (SrIR = .60 min, P &lt; .001), but there was no significant difference between the JrIR and SrIR (P = .058). Furthermore, trainees supervised by non-pediatric IRs had even greater median FT (1.30 min). All of these differences were significantly greater in smaller patients (Age &lt;1) and cases in which increased procedural difficulty was encountered. &#x0D; &#x0D; Conclusion: &#x0D; This study suggests that the experience of the proceduralist may reduce radiation exposure in PICC placements, but it does not seem to support linear improvement early in a primary operator’s career. The results raise the question as to why the differences exist and may support the use of FT as a metric for analyzing proficiency in IR procedures.

A note on the large charge expansion in 4d CFT

In this letter, we discuss certain universal predictions of the large charge expansion in conformal field theories with U(1) symmetry, mainly focusing on four-dimensional theories. We show that, while in three dimensions quantum fluctuations are responsible for the existence of a theory-independent Q0 term in the scaling dimension ΔQ of the lightest operator with fixed charge Q≫1, in four dimensions the same mechanism provides a universal Q0log⁡Q correction to ΔQ. Previous works discussing four-dimensional theories failed in identifying this term. We also compute the first subleading correction to the OPE coefficient corresponding to the insertion of an arbitrary primary operator with small charge q≪Q in between the minimal energy states with charge Q and Q+q, both in three and four dimensions. This contribution does not depend on the operator insertion and, similarly to the quantum effects in ΔQ, in four dimensions it scales logarithmically with Q.

Distractions in the cardiac catheterisation laboratory: impact for cardiologists and patient safety

ObjectiveTo understand human factors (HF) contributing to disturbances during invasive cardiac procedures, including frequency and nature of distractions, and assessment of operator workload.MethodsSingle centre prospective observational evaluation of 194 cardiac...

Model-dependence of minimal-twist OPEs in d > 2 holographic CFTs

Following recent work on heavy-light correlators in higher-dimensional conformal field theories (CFTs) with a large central charge CT, we clarify the properties of stress tensor composite primary operators of minimal twist, [Tm], using arguments in both CFT and gravity. We provide an efficient proof that the three-point coupling leftlangle {mathcal{O}}_L{mathcal{O}}_Lleft[{T}^mright]rightrangle , where {mathcal{O}}_L is any light primary operator, is independent of the purely gravitational action. Next, we consider corrections to this coupling due to additional interactions in AdS effective field theory and the corresponding dual CFT. When the CFT contains a non-zero three-point coupling leftlangle TT{mathcal{O}}_Lrightrangle , the three-point coupling leftlangle {mathcal{O}}_L{mathcal{O}}_Lleft[{T}^2right]rightrangle is modified at large CT if leftlangle TT{mathcal{O}}_Lrightrangle sim sqrt{C_T} . This scaling is obeyed by the dilaton, by Kaluza-Klein modes of prototypical supergravity compactifications, and by scalars in stress tensor multiplets of supersymmetric CFTs. Quartic derivative interactions involving the graviton and the light probe field dual to {mathcal{O}}_L can also modify the minimal-twist couplings; these local interactions may be generated by integrating out a spin-ℓ ≥ 2 bulk field at tree level, or any spin ℓ at loop level. These results show how the minimal-twist OPE coefficients can depend on the higher-spin gap scale, even perturbatively.

Variation in Intensive Care Unit Intubation Practices in Pulmonary Critical Care Medicine Fellowship.

Background: Endotracheal intubation in the intensive care unit (ICU) is a high-risk procedure. Competence in endotracheal intubation is a requirement for Pulmonary and Critical Care Medicine (PCCM) training programs, but fellow experience as the primary operator in intubating ICU patients has not been described on a large scale.Objective: We hypothesized that significant variation surrounding endotracheal intubation practices in medical ICUs exists in U.S. PCCM training programs.Methods: We administered a survey to a convenience sample of U.S. PCCM fellows to elicit typical intubation practices in the medical ICU.Results: Eighty-nine discrete U.S. PCCM and Internal Medicine Critical Care Medicine training programs (77% response rate) were represented. At 43% of programs, the PCCM fellow was “always or almost always” designated the primary operator for intubation of a medical ICU patient, whereas at 21% of programs, the PCCM fellow was “rarely or never” the primary operator responsible for intubating in the ICU. Factors influencing this variation included time of day, hospital policies, attending skill or preference, ICU census and acuity, and patient factors. There was an association between location of the training program, but not program size, and whether the PCCM fellow was the primary operator.Conclusion: There is significant variation in whether PCCM fellows are the primary operators to intubate medical ICU patients during training. Further work should explore how this variation affects fellow career development and competence in intubation.

Association between Implant Primary Stability and Operator Experience - A Retrospective Hospital Based Study

Primary stability plays a major role in determining the success of implant therapy. The main aim of this study was to investigate the association between primary stability and operators experience. This retrospective study was conducted among operators who placed implants in Saveetha Dental College, Chennai. Data were reviewed and collected from 86,000 patient records over ten months from June 2019 to March 2020. Data collected was assessed and tabulated using Microsoft excel. The study included 990 implant sites from 476 patients with a mean age of 42.5 years and a gender distribution of 293 males and 183 females. Implants were placed by 125 operators who belonged to different years of study. The gender distribution of the operators included 73 males and 52 females. Data collected was then exported to Microsoft Excel 2010. The collected data were then subjected to statistical analysis using the Statistical Package for Social Science (SPSS). The most frequently obtained primary stability value was 30-40 Ncm with 53.8%. It was observed that clinicians with four or more years of experience place more implants when compared to others with 69.7% of the total study sample. Clinicians with four or more years of experience attain the optimum insertion torque value of 30-40 Ncm. Within the limits of the study, the implants were most frequently placed by students with four or more years of experience and the most frequent primary stability value observed was 30-40 Ncm. Insertion torque value of 30-40 Ncm was obtained by students with four or more years of experience.

Can a Primary Operator Be Separated From the Team’s Success?

Can a Primary Operator Be Separated From the Team’s Success?