Towards quantum simulations in particle physics and beyond on noisy intermediate-scale quantum devices

We review two algorithmic advances that bring us closer to reliable quantum simulations of model systems in high-energy physics and beyond on noisy intermediate-scale quantum (NISQ) devices. The first method is the dimensional expressivity analysis of quantum circuits, which allows for constructing minimal but maximally expressive quantum circuits. The second method is an efficient mitigation of readout errors on quantum devices. Both methods can lead to significant improvements in quantum simulations, e.g. when variational quantum eigensolvers are used. This article is part of the theme issue 'Quantum technologies in particle physics'.

Assessing the position of pacemaker leads via transthoracic echocardiography: a prospective study

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND/ INTRODUCTION

Lead-induced tricuspid regurgitation (TR) in patients with cardiac implantable electronic devices (CIED) is associated with increased morbidity and mortality. Mechanisms proposed to explain CIED-induced TR can be classified as primary (implantation-related, lead-related) and secondary (pacing related). Primary CIED-induced TR results from the direct interaction of the lead with the tricuspid valve (TV). Determination of exact lead position via echocardiography is crucial however often difficult via standard views. Previous research has shown the value of an atypical subcostal 2D en-face view to describe the exact anatomy of the TV (Figure 1) (1-3).

PURPOSE

In this prospective observational investigation, we aimed to demonstrate the feasibility of the subcostal 2D en-face view of the TV to determine RV lead position at the level of TV passage and thereby to unmask potentially unfavorable lead-positions and interactions with the TV, which might otherwise remain unnoted.

METHODS

Consecutive patients who underwent implantation of CIED with at least one RV lead were prospectively included. Comprehensive transthoracic echocardiography (TTE) was performed before and after the procedure. An en-face view of the TV by an approximately 90° counter-clockwise rotation of the transducer from a standard subcostal 4-chamber view was attempted in all patients. Exact lead-position (e.g. postero-septal commissural, central, etc., see Figure 1) was described whenever possible.

RESULTS

A total of  35 patients were included in the final analysis, median age was 62 years, 27/35 (77%) were male.

Thirteen patients (37%) already had an RV lead prior to the recent procedure and therefore showed 2 or more leads passing the TV in post-procedural controls.

Implanted devices included cardiac contractility modulation (CCM) (7/35 patients, 20%), implantable cardioverter-defibrillator (ICD) (11/35 patients, 31%), cardiac resynchronization therapy (CRT) (7/35 patients 20%) and pacemaker (PM) (7/35 patients, 20%). Three patients (9%) received an additional RV lead due to RV lead dysfunction.

The exact position of the RV lead could be determined applying the en-face view in 27/35 patients (77%). In the majority of cases (20/35 patients, 57%), the RV lead passed through the tricuspid plane in a postero-septal commissural position. Central trajectory was observed in 5/35 patients (14%). Anteroseptal and anteroposterior passage were each found in one patient.

In the remaining 8/35 patients (23%), lead position could not be determined due to inferior image quality from the subcostal view.

CONCLUSIONS

RV lead position can be determined from a subcostal en-face view of the TV in a majority of patients after CIED implantation. Hereby, 2D-TTE can add significant value to the management, follow-up, and monitoring and should therefore be included in the standard TTE protocol of every patient with CIED. Abstract Figure 1

Peri- and intraoperative EEG signatures in newborns and infants

OBJECTIVE

The electroencephalographic derived indices have been developed for adult patients, however these monitors have not been validated for infants.

METHODS

Frontal EEGs were recorded in 115 infants aged <1 year [0-3-months (N = 27), 4-6-months (N = 30), 7-9-months (N = 29) and 10-12-months (N = 29)] who received general anaesthesia with sevoflurane. Total power (µV²) and relative β-, α-, θ-, δ-power (%) were analyzed. Additionally, in 20 EEGs event marker were added (baseline, loss of consciousness, intraoperative situation, extubation) to assess perioperative EEG dynamics.

RESULTS

Newborns show a mean relative δ-power at 80% in intraoperative EEG compared to infants (10-12 months) showing 47.5%. Relative β-power and α-power are low in newborns (mean 3.2% and 4.6%; respectively), with a marked increase in the older infants (4-6 months) (mean 10.9% and 14.4%; respectively). EEG dynamic in newborns from baseline (relative δ-power of 88%) to the intraoperative situation (80.5%) are discrete. In contrast infants >6-months have a strong reduction of relative δ-power from baseline to the intraoperative situation, which corresponds to an increase of faster frequencies.

CONCLUSIONS

Age dependent perioperative EEG signatures can be demonstrated in infants younger than one year.

SIGNIFICANCE

We demonstrate significant differences in EEG readouts between newborns and infants which questions our monitoring systems in paediatric anaesthesia.

Right ventricular longitudinal strain on cardiovascular magnetic resonance imaging predicts outcome in patients undergoing transcatheter mitral valve repair

Background

The prognostic value of left and right ventricular global longitudinal strain (LV and RV GLS) derived from cardiovascular magnetic resonance (CMR) feature tracking in patients with severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR) is unknown.

Methods

Consecutive patients scheduled for TMVR underwent pre-procedural and follow-up CMR imaging including feature tracking strain analysis. Kaplan-Meier estimates and multivariate Cox-regression analyses were used to identify the prognostic impact of LV and RV GLS on CMR using a composite of heart failure hospitalization and death.

Results

A total of 62 patients (78.3±7.0y/o, 45% female, EuroSCORE II: 9.7±7.2%) with severe MR underwent CMR prior to TMVR. 23 (37%) patients presented with right ventricular dysfunction (RVD) defined by RV GLS &gt;−20% on CMR. At baseline, RVD was associated with NT-proBNP levels (9510 vs. 4064pg/mL, p=0.030). On CMR, RVD was associated with reduced left and RV ejection fraction (LVEF: 39.2 vs. 48.7%, p=0.011, RVEF: 35.1 vs. 46.7%, p&lt;0.001), as well as increased LV GLS (−14.0 vs. −19.5%, p=0.003).

A total of 18 events (12 deaths, 6 hospitalizations for heart failure) occurred during follow-up (mean 11.4±9.1months). While LV GLS was not significantly associated with outcome (HR 0.95, 95% CI: 0.90–1.01, p=0.082), RV GLS showed a strong and independent association with event-free survival by multivariate Cox-regression analysis (adj.HR 0.91, 95% CI: 0.83–0.99, p=0.033) after adjustment for relevant baseline and procedural data (EuroSCORE II, post-procedural residual MR), imaging parameters (TAPSE, LV and RVEF on CMR), and cardiac biomarkers (NT-proBNP). When compared with the “gold standard” RVEF on CMR (RVEF &lt;45%: adj.HR 0.86, 95% CI: 0.23–3.20, p=0.825) and TAPSE on echo (TAPSE &lt;17mm: adj.HR: 2.77, 95% CI: 0.72–10.70, p=0.140), only RVD (RV GLS &gt;−20%: adj.HR 5.05, 95% CI: 1.23–20.63, p=0.024) was significantly associated with the composite endpoint (Figure 1). Follow-up CMR was performed in 21 (34%) patients. RV GLS significantly improved after TMVR (−20.6 to −25.2%, p=0.016, Figure 2).

Conclusions

RV rather than LV GLS, as determined on CMR, is an important predictor of outcome in patients undergoing TMVR. At 1 year follow-up, RV function significantly improved, and thus might add useful prognostic information on top of established risk factors.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Prevalence of cardiac amyloidosis in patients undergoing transcatheter edge-to edge mitral valve repair

Introduction

Cardiac amyloidosis (CA) is associated with severe aortic stenosis, however, its prevalence in patients with severe mitral regurgitation in elderly patients is unknown.

Methods

Patients scheduled for transcatheter edge-to edge mitral valve repair (TMVR) were prospectively screened for CA using 99m technetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) bone scintigraphy and subsequent serum as well as urine free light-chain quantification in case of a positive DPD scan, defined as visual cardiac update based on the Perugini grading scale.

Results

Out of 100 patients undergoing TMVR, 28 patients (28.0%) had a positive DPD-scan (DPD+). 14 patients (14.0%) showed Perugini grade I enhancement, 9 patients (9.0%) grade II enhancement, and in 5 patients (5.0%), grade III enhancement was present. 28 patients suffered from TTR and two from AL- amyloidosis (one patient had a combination of TTR and AL-amyloidosis). When compared to patients with a negative scan (DPD-), DPD+ patients presented with similar baseline characteristics such as age (DPD- vs DPD+ 76y/o vs 77y/o, p=0.44), gender (female; 62.7% vs 50.0%, p=0.25), coronary artery disease (59.7% vs 42.9%, p=0.13), previous valve surgery (25.4% vs 14.3%, p=0.24) and atrial fibrillation (68.7% vs 78.6%, p=0.33). Also, NYHA functional class and EuroScore II were similar (NYHA ≥ III; 85.1% vs 82.1%, p=0.72, and EuroScore II 9.9±9.8% vs 7.0±4.8%, p=0.21, respectively). On echocardiography, DPD+ patients presented with more pronounced left and right ventricular hypertrophy (interventricular septum: 15mm vs 13mm, p&lt;0.01) but similar left ventricular ejection fraction (44.9% vs 42.3%, p=0.34). At 3-months after TMVR, DPD+ patients showed significant improvement in BNP serum levels when compared to DPD- patients (DPD+ vs DPD-: +315±2569pg/ml vs −2404±8696pg/ml, p=0.03), while NYHA functional class remained unchanged (NYHA improvement ≥1 class: 57.6% vs 50.0%, p=0.52)

Conclusions

In this single centre experience, CA was highly prevalent among elderly patients with severe mitral regurgitation scheduled for TMVR. TMVR in CA patients resulted in significant improvement of NT-pro BNP levels. Future studies need to clarify the prognostic relevance of CA in this specific patient population.

Funding Acknowledgement

Type of funding sources: None.

Transcatheter versus surgical valve repair in patients with severe mitral regurgitation

Background

Transcatheter edge-to-edge mitral valve repair (TMVR) is increasingly performed, however, its efficacy in comparison with surgical MV treatment (SMV) is unknown.

Methods

Consecutive patients with severe mitral regurgitation (MR) undergoing TMVR (68% functional, 32% degenerative) or SMV (9% functional, 91% degenerative; 23% MV replacement) were enrolled. To account for differences in baseline characteristics, propensity score-matching including age, EuroSCORE-II, left ventricular ejection fraction, and NT-proBNP was performed. A composite of heart failure (HF) hospitalization/death was defined as primary endpoint. Kaplan-Meier curves and Cox-regression analyses were used to investigate associations between baseline, imaging, and procedural parameters and outcome.

Results

Between July 2017 and April 2020, 245 patients were enrolled, of which 102 patients could be adequately matched (73y/o, 61% females, EuroSCORE-II: 5.7%, p&gt;0.05 for all). Despite matching, TMVR patients were sicker at baseline (higher rates of prior myocardial infarction, coronary revascularization, pacemakers/defibrillators, and diabetes mellitus, p&lt;0.009 for all).

Patients were followed for 28.3±27.2 months, during which 27 events (17 deaths, 10 HF hospitalizations) occurred.Postprocedural MR reduction (MR grade &lt;2: TMVR vs. SMV: 88% vs. 94%, p=0.487) and freedom from HF hospitalization/death (log-rank: p=0.221) were similar at two years. By multivariable Cox analyses, EuroSCORE-II (adj.HR 1.07 [95% CI: 1.00–1.13], p=0.027) and postprocedural MR severity (adj.HR 1.85 [95% CI: 1.17–2.92], p=0.009) emerged as independent predictors of outcome.

Conclusions

In this propensity matched, all-comers cohort, 2-year outcomes after TMVR versus SMV were similar. Given the reported favorable long-term durability of TMVR, the interventional approach emerges as valuable alternative for a substantial number of patients with functional and degenerative MR at high/prohibitive surgical risk.

Funding Acknowledgement

Type of funding sources: None.

Quantitative characterization of AEB pulses across the modern fleet

OBJECTIVE

Characteristics of specific Automatic Emergency Braking (AEB) pulses can result in increased motion of the occupant, which can lead to the occupant being out-of-position such that when a crash occurs protection may be compromised. Quantifying these variations across the modern fleet is crucial to understand the loading environment to which vehicle occupants are exposed. Therefore, we categorized the AEB pulses based on acceleration pulse features such as deceleration magnitude, jerk, and ramp time.

METHODS

A total of 2278 AEB vehicle tests (years 2013-2019) were extracted from the Insurance Institute for Highway Safety (IIHS) database and analyzed. The following pulse characteristics were extracted: Jerk (g/s), Ramp-time (s), and Maximum deceleration (g). A subset of tests in which the tested vehicle did not contact the foam target (n = 1665) was analyzed further, with the following additional variables extracted: Deceleration time (s), Steady-state deceleration (g), and Duration (s). Other non-pulse related features were also considered: Test speed (20 and 40 km/h), Curb weight (Kg), and Vehicle Model Year. Using machine learning methods, the pulses were categorized into clusters. One-way ANOVAs for continuous variables and X² for categorical features were used to assess differences between clusters (p ≤ 0.05).

RESULTS

Using the entirety of the AEB vehicle tests extracted (n = 2278), a total of 3 clusters were selected. The three clusters showed significantly different Jerk, Ramp-time, and Maximum deceleration (p < 0.001). Target contact decreased in AEB tests with more recent vehicle model years (rate of contact 66% in 2014 vs 1.7% in 2019). In one cluster, Jerk and Maximum deceleration increased with vehicle model year. Using the subset of tests in which there was no contact with the foam target (n = 1665), 4 categories of pulses were selected. In both sets of clusters, Ramp-time and Jerk showed moderate inverse correlation (r = -0.7), while all other features showed a low correlation.

CONCLUSIONS

These results show that AEB technology improved over the years in obstacle avoidance. The identification of AEB pulse clusters is important in order to describe distinct approaches to achieving AEB and to be able to reproduce representative AEB pulses in the laboratory and understand the influences of those pulses on occupants' motion.

AB0341 SLE PREGNANCIES AT HIGH RISK FOR PRE-ECLAMPSIA BENEFIT MOST FROM COMBINATION OF LOW DOSE ASPIRIN AND HYDROXYCHLOROQUINE

Background:

Women with SLE face a high risk of preeclampsia (PE). Low dose Aspirin (LDA) is known to protect against PE in non-autoimmune patients and is recommended for SLE patients1. Besides, a beneficial effect of hydroxychloroquine (HCQ) on the occurrence of PE has recently been discussed2.

Objectives:

To investigate the influence of LDA and HCQ on the occurrence of PE in SLE patients.

Methods:

Pregnancies of women with SLE from an outpatient pregnancy clinic were prospectively evaluated. Clinical characteristics, medication use and pregnancy outcomes were analysed. Association of LDA use (latest from gestational week 16 on) and HCQ use (from 1st trimester on) with PE were analysed using a multiple logistic regression model (adjustment for age, BMI, hypertension, disease activity in 1st trimester, lupus nephritis, nulliparity, history of PE and high-risk aPL profile3).

Results:

We enrolled 190 lupus pregnancies (148 women, 1995-2019). Additional risk factors for PE were present in 83.7%: 55.8% showed a high-risk profile (HRP) for PE according to ACOG4 (history of PE, hypertension, lupus nephritis or aPL), another 27.9% had at least one moderate risk factor (nulliparous, BMI>30 or age>35) (see table 1).

Each 20.5% of pregnancies received HCQ only or LDA only, while 22.6% were prescribed both drugs. 36.3% took neither HCQ nor LDA. Women with HRP were more likely to take LDA alone or in combination with HCQ (28.3% and 35.8%, respectively).

PE occurred in 13.2% of pregnancies (7.7% in HCQ only, 15.4% in LDA only, 14.0% in HCQ and LDA, 14.5% in no HCQ or LDA). Most pregnancies affected by PE carried a HRP (88.0%).

Use of LDA was significantly associated with a lower risk for PE [aOR 0.21 (95%-CI 0.05-0.99), p<0.05]. HCQ use also had a moderating effect on the incidence of PE, but this effect did not reach significance [aOR 0.47 (95%-CI 0.15-1.52), p=0.21]. If only pregnancies with HRP were considered, the effect size increased for HCQ (LDA [aOR 0.18 (95%-CI 0.04-0.96), p<0.05], HCQ [aOR 0.28 (95%-CI 0.07-1.14), p=0.075]).

Conclusion:

In this prospective real-life cohort, timely LDA medication was associated with a lower risk of PE in SLE pregnancies. In a multiple regression model taking LDA and HCQ into account, the favourable effect on the occurrence of PE was partially explained by HCQ. In particular, SLE patients at high risk for PE seem to benefit from HCQ during pregnancy. Future research may reveal mechanisms by which HCQ might lower the incidence of PE.

References:

[1]doi: 10.1136/annrheumdis-2016-209770

[2]doi: 10.1111/bcp.14131

[3]doi: 10.1136/annrheumdis-2019-215213

[4]doi: 10.1097/AOG.0000000000002708

Table 1.

Patient characteristics and risk profile

HCQ only (n=39)LDA only (n=39)HCQ + LDA (n=43)no HCQor LDA(n=69)Patient characteriticsAge (years), median (IQR)29 (25-33)32 (30-33)30 (28.5-33.5)31 (28-35)BMI, median (IQR)23.5 (22-25)23 (22-24)22 (22-24)23 (22-24)Chronic Hypertension, n (%)7 (17.9%)9 (23.1%)6 (14.0%)9 (13.0%)Preconception counselling, n (%)23 (59.0%)28 (71.8%)35 (81.4%)41 (59.4 %)Obstetrical historyNulliparous, n (%)20 (51.3%)26 (66.7%)33 (76.7%)36 (52.2%)Previous fetal loss, n (%)1 (2.6%)10 (25.6%)14 (32.6%)10 (14.5%)Previous PE, n (%)2 (5.1%)4 (10.3%)4 (9.3%)5 (7.2%)SLE characteristicsand therapyDisease duration (years), median (IQR)7.0 (2.0-11.0)7.5 (3.0-11.5)6.7 (3.4-10.0)6.0 (3.0-9.2)SLEDAI, median (IQR)2.0 (1.0-4.3)2.0 (0-2.5)4.0 (2.0-4.0)2.0 (0-4.0)Lupus nephritis, n (%)9 (23.1%)13 (33.3%)18 (41.9%)14 (20.3%)Anti-dsDNA antibodies, n (%)22 (56.4%)15 (38.5%)36 (83.7%)33 (47.8%)Prednisolone therapy, n (%)26 (66.7%)15 (38.5%)25 (58.1%)29 (42.0%)Prednisolone (mg/d), median (IQR)5.0 (5.0-8.0)5.0 (5.0-7.5)5.0 (4.0-5.0)5.0 (5.0-8.0)aPL statusAPS, n (%)-12 (30.8%)14 (32.6%)2 (2.9%)Any positive aPL, n (%)-20 (51.3%)19 (44.2%)5 (7.2%)LAC, n (%)-15 (38.5%)13 (30.2%)3 (4.3%)ACL, n (%)-14 (35.9%)13 (30.2%)4 (5.8%)β2-GP1, n (%)-12 (30.8%)12 (27.9%)2 (2.9%)

LAC = Lupus anticoagulant, ACL = Anticardiolipin antibody, β2-GP1 = β2-Glycoprotein I antibody

Disclosure of Interests:

None declared

OP0296 THE 2021 DORIS DEFINITION OF REMISSION IN SLE – FINAL RECOMMENDATIONS FROM AN INTERNATIONAL TASK FORCE

Background:

Remission is the stated goal for both patient and care-giver (1), but consensus on a definition of remission has been lacking. Previously, an international task force consisting of patient representatives and medical specialists published a frame-work for such a definition (2), but without making a final recommendation.

Objectives:

To achieve consensus around a definition of remission in SLE (DORIS).

Methods:

The DORIS task force met annually from 2015 to 2020 and consisted of patient representatives and specialists in rheumatology, nephrology, dermatology, and clinical immunology. Systemic literature reviews of several key topics were done and specific research questions were examined in suitably chosen datasets. The findings were discussed, reformulated as recommendations, and voted upon. Level of evidence (LoE), strength of recommendation (SoR), and agreement were determined in standard fashion. The final recommendation for the DORIS definition of remission was established by electronic vote after finalization of the minutes of the most recent task force meeting.

Results:

Based on data from the literature and from several SLE-specific data sets, five key recommendations were endorsed (Table 1) that should be seen as additions to those published previously (2). Literature reviews identified strong support for the face-, content-, construct- and criterion validity of the definition based on the clinical SLEDAI (not including anti-DNA and complement) equal to zero plus low physician global assessment and allowing stable medical treatment. Thus, the DORIS Task Force recommended a single definition of remission in SLE, based on clinical SLEDAI = 0, evaluator’s global assessment <0.5 (0-3), prednisone 5 mg/day or less, and stable antimalarials, immunosuppressives and biologics.

Table 1.Vote in favorLoESoRAgreement1.Inclusion of serology [anti-DNA, complement] in the DORIS definition of remission-on-treatment does not meaningfully alter the construct validity and therefore it is not recommended to include it90%2aB8.382.While the goal of treatment is sustained remission, a definition of remission should be able to be met at any point in time; therefore, duration should not be included in the definition100%5C9.023.To date, the SLEDAI-based definitions of remission have formally been investigated more extensively than BILAG-or ECLAM-based definitions. The SLEDAI-based definitions can therefore more confidently be recommended91%2aB9.254.Remission off treatment, while the ultimate goal for many patients and providers, is achieved very rarely. In clinical research and as an outcome in clinical trials, the definition for remission-on-treatment is recommended92%2aB9.525.In clinical trials, the LLDAS definition for low disease activity and the DORIS definition of remission are both recommended as outcomes100%5C9.25

The 2021 DORIS definition of remission in SLE:

Conclusion:

The 2021 DORIS definition of remission in SLE was established. It is recommended for use as an aspirational treatment target in clinical care, a clear concept in education, and a key outcome in research including clinical trials and observational studies.

References:

[1]van Vollenhoven RF, Mosca M, Bertsias G, et al. Treat-to-target in systemic lupus erythematosus: recommendations from an international task force. Ann Rheum Dis 2014;73:958-67.

[2]van Vollenhoven R, Voskuyl A, Bertsias G, et al. A framework for remission in SLE: consensus findings from a large international task force on definitions of remission in SLE (DORIS). Ann Rheum Dis 2016.

Disclosure of Interests:

Ronald van Vollenhoven Speakers bureau: AbbVie, Galapagos, GSK, Janssen, Pfizer, UCB, Consultant of: AbbVie, AstraZeneca, Biogen, Biotest, Celgene, Galapagos, Gilead, Janssen, Pfizer, Sanofi, Servier, UCB, Vielabo, Grant/research support from: BMS, GSK, Lilly, UCB, George Bertsias: None declared, Andrea Doria: None declared, David Isenberg: None declared, Eric F. Morand: None declared, Michelle A Petri: None declared, Bernardo Pons-Estel Consultant of: GSK, Janssen, Anisur Rahman: None declared, Manuel Ugarte-Gil Grant/research support from: Janssen, Pfizer, Alexandre Voskuyl: None declared, Laurent Arnaud Consultant of: Alexion, Amgen, Astra-Zeneca, BMS, GSK, Janssen-Cilag, LFB, Lilly, Menarini France, Medac, Novartis, Pfizer, Roche-Chugaï, UCB., Ian N. Bruce: None declared, Ricard Cervera Consultant of: GSK, Alexion, Eli Lilly, Astra Zeneca, Termo-Fisher, Rubió, Nathalie Costedoat-Chalumeau: None declared, Caroline Gordon Speakers bureau: UCB, Consultant of: Center for Disease Control, Astra-Zeneca, MGP, Sanofi, UCB, Frederic Houssiau: None declared, Marta Mosca: None declared, Matthias Schneider: None declared, Michael Ward: None declared, Cynthia Aranow: None declared.

Sarcopenia and surgical outcomes in patients undergoing oncologic colonic surgery

Objective

Sarcopenia is a marker for malnutrition and frailty which could lead to higher complication rate and prolonged length of stay (LOS) after surgery. The study aim was to assess the correlation between sarcopenia and clinical outcomes in oncologic colonic surgery.

Methods

This retrospective study included consecutive patients operated between 2014 and 2019. Three radiological indices of sarcopenia were measured at the level of the third lumbar vertebra on preoperative CT scans: Skeletal Muscle Area (SMA), Skeletal Muscle Radiation Attenuation (SMRA), and Skeletal Muscle Index (SMI). Patients with major complications (&gt; grade 3a) according to Clavien classification were compared to those without. Statistical correlation between sarcopenia indices, LOS and Comprehensive Complication Index (CCI) was tested by use of the Pearson correlation.

Results

A total of 325 patients were included, 50 (15.4%) with and 275 (84.6%) without major complications. SMA and SMI were comparable between both groups (respectively 126.0 vs 125.2 cm2, p = 0.974, and 43.4 vs 44.3 cm2/m2, p = 0.636), while SMRA was significantly lower in patients with major complications (33.6 vs 37.3 HU, p = 0.018). A lower SMRA was correlated with prolonged LOS (r=-0.207, p &lt; 0.01) and higher CCI (r=-0.144, p &lt; 0.01), while the other sarcopenia indices had no influence on surgical outcomes.

Conclusion

Preoperative SMRA or muscle quality appears to be a weak predictor for adverse outcomes after oncologic colectomy.

External validation of three nomograms predicting survival using an international cohort of patients with resected pancreatic head ductal adenocarcinoma

Objective

Lymph node ratio (LNR, positive lymph nodes/collected lymph nodes during surgery) was identified as an important prognostic factor of survival in resected pancreatic cancer. Several nomograms based on LNR were recently proposed to predict survival after pancreatoduodenectomy (PD). The present study aimed to externally validate 3 published nomograms using an international cohort.

Methods

Consecutive patients with ductal adenocarcinoma of the pancreatic head who underwent PD without neoadjuvant treatment from 6 tertiary centers in Europe and the USA were retrospectively collected from 2000 to 2017. Patients with metastases at diagnosis, R2 resection, missing data regarding LNR, and who died within 90 postoperative days were excluded. The 3 selected nomograms were the updated Amsterdam nomogram (including LNR, adjuvant therapy, margin status, and tumor grade), the nomogram by Pu et al. (including LNR, age, tumor grade, and T stage) and the nomogram by Li et al. (including LNR, age, tumor location, grade, size, and TNM stage). Overall survivals (OS) were calculated using Kaplan-Meier method. For the validation, calibration (Hosmer-Lemeshow test), discrimination capacity (ROC curves for 3-year OS), and clinical utility (sensitivity and specificity at the value of Youden index) were assessed.

Results

After exclusion of 95 patients with metastases, R2 resection, and who died within 90 postoperative days, 1167 patients were included. Median OS of the entire cohort was 23 months (95% confidence interval: 21-24).

For the 3 nomograms, Kaplan-Meier curves showed significant diminution of OS with increasing scores (p &lt; 0.01 for the 3 nomograms). All nomograms showed good calibration (non significant Hosmer-Lemeshow goodness-of-fit tests). For the updated Amsterdam nomogram, the area under the ROC curve (AUROC) for 3-year OS was 0.66. Sensitivity and specificity were 73% and 50%. Regarding the nomogram by Pu et al., the AUROC was 0.67. Sensitivity and specificity were 65% and 60%. For the nomogram by Li et al., the AUROC was 0.67, while sensitivity and specificity were 56% and 71%.

Conclusion

The 3 selected nomograms were validated using an external international cohort and displayed interesting and comparable predictive values. Those nomograms may be used in clinical practice to estimate survival after PD for ductal adenocarcinoma.

Technical advances in surgery for pancreatic cancer

BACKGROUND

Multimodal treatment concepts enhance options for surgery in locally advanced pancreatic ductal adenocarcinoma (PDAC). This review provides an overview of technical advances to facilitate curative-intent resection in PDAC.

METHODS

A review of the literature addressing current technical advances in surgery for PDAC was performed, and current state-of-the-art surgical techniques summarized.

RESULTS

Artery-first and uncinate-first approaches, dissection of the anatomical triangle between the coeliac and superior mesenteric arteries and the portomesenteric vein, and radical antegrade modular pancreatosplenectomy were introduced to enhance the completeness of resection and reduce the risk of local recurrence. Elaborated techniques for resection and reconstruction of the mesenteric-portal vein axis and a venous bypass graft-first approach frequently allow resection of PDAC with venous involvement, even in patients with portal venous congestion and cavernous transformation. Arterial involvement does not preclude surgical resection per se, but may become surgically manageable with recent techniques of arterial divestment or arterial resection following neoadjuvant treatment.

CONCLUSION

Advanced techniques of surgical resection and vessel reconstruction provide a toolkit for curative-intent surgery in borderline resectable and locally advanced PDAC. Effects of these surgical approaches on overall survival remain to be proven with high-level clinical evidence.

[Assessment of energy density during laser photoselective vaporisation of the prostate: A retrospective monocentric study]

INTRODUCTION

Greenlight XPS-180W® (AMS, San José, USA) photoselective vaporisation of the prostate (PVP) is considered as an alternative to transurethral resection of the prostate. The objective of this study was to assess the effect of energy density applied on adenoma during PVP treatment for benign prostate hyperplasia (BPH) on postoperative outcomes.

METHODS

A single-centre retrospective study has been conducted in the department of Urology of Colmar Hospital, in patients with symptomatic BPH, treated by PVP, between January 2016 and January 2019. Patients were stratified into two groups according to energy delivered and prostate volume as determined preoperatively: Low density (<4kJ/mL) and high density (>4kJ/mL). Perioperative complications, PSA evolution and functional outcomes (International Prostate Symptom Score, quality of life, maximum urinary flow rate, post-void residual urine volume) were compared with a minimal delay of 6 months. The retreatment rate was similar in the two groups.

RESULTS

A total of 215 patients were included with median follow-up of 25 months. High energy density was associated with less glandular volume. There were no statistically significant differences between the two groups concerning the perioperative complications and the functional outcomes. The postoperative reduction of the PSA level was more significant in the high-energy group (41% vs. 28%, P=0.03).

CONCLUSION

The perioperative complications and functional outcomes of PVP with Greenlight XPS-180W® laser are equivalent depending on the energy density delivered. The greater decrease in postoperative PSA for high-energy density could nevertheless suggest better quality tissue destruction.

LEVEL OF PROOF

3.

A new class of focusing crystal shapes for Bragg spectroscopy of small, point-like, x-ray sources in laser produced plasmas

This paper describes a new class of focusing crystal forms for the x-ray Bragg crystal spectroscopy of small, point-like, x-ray sources. These new crystal forms are designed with the aid of sinusoidal spirals, a family of curves, whose shapes are defined by only one parameter, which can assume any real value. The potential of the sinusoidal spirals for the design x-ray crystal spectrometers is demonstrated with the design of a toroidally bent crystal of varying major and minor radii for measurements of the extended x-ray absorption fine structure near the Ta-L3 absorption edge at the National Ignition Facility.

Rhizomucor hepatosplenic abscesses in a patient with renal and pancreatic transplantation

Fungal infections are generally observed in immunosuppressed patients only, with a diagnostic challenge due to non-specific symptoms. For this reason, appropriate management may be delayed. This case report concerns a 36-year-old man with history of pancreas and kidney transplantation. He had chemotherapy for post-transplant B-cell lymphoma and presented with left upper abdominal pain and fever. Multiple investigations led to a final diagnosis of disseminated abdominal mucormycosis with multiple Rhizomucor abscesses in the liver, spleen and kidney transplant. Treatment was antifungal therapy and laparotomy with splenectomy, wedge resection of two fungal abscesses in segments II and IVb, and segmental left colic resection.

Controlling the Nonlinear Relaxation of Quantized Propagating Magnons in Nanodevices

Relaxation of linear magnetization dynamics is well described by the viscous Gilbert damping processes. However, for strong excitations, nonlinear damping processes such as the decay via magnon-magnon interactions emerge and trigger additional relaxation channels. Here, we use space- and time-resolved microfocused Brillouin light scattering spectroscopy and micromagnetic simulations to investigate the nonlinear relaxation of strongly driven propagating spin waves in yttrium iron garnet nanoconduits. We show that the nonlinear magnon relaxation in this highly quantized system possesses intermodal features, i.e., magnons scatter to higher-order quantized modes through a cascade of scattering events. We further show how to control such intermodal dissipation processes by quantization of the magnon band in single-mode devices, where this phenomenon approaches its fundamental limit. Our study extends the knowledge about nonlinear propagating spin waves in nanostructures which is essential for the construction of advanced spin-wave elements as well as the realization of Bose-Einstein condensates in scaled systems.