Threshold Volume Research Articles

Correlations Between Physician and Hospital Stroke Thrombectomy Volumes and Outcomes: A Nationwide Analysis.

Despite the Joint Commission’s certification requirement of ≥15 stroke thrombectomy (ST) cases per center and proceduralist annually, the relationship between ST case volumes and outcomes is uncertain. We sought to determine whether a proceduralist or hospital volume threshold exists that is associated with better outcomes among Medicare beneficiaries. Retrospective cohort study using validated International Classification of Diseases, Tenth Revision, Clinical Modification codes to identify admissions with acute ischemic stroke and treatment with ST. We used de-identified, national 100% inpatient Medicare data sets from January 1, 2016, to December 31, 2017 for US individuals aged ≥65 years. We calculated total procedures by proceduralist and hospital. We performed adjusted logistic regression of total cases as a predictor of inpatient mortality, good outcome (defined by dichotomized discharge disposition of inpatient rehabilitation or better), and 30-day readmission. We adjusted for sex, age, Charlson Comorbidity Index, availability of neurocritical care, teaching hospital status, socioeconomic status, 2-year stroke volume, and urban versus rural hospital location. We dichotomized case numbers incrementally to determine a volume threshold for better outcomes. Thirteen thousand three hundred thirty-five patients were treated with ST by 2754 proceduralists at 641 hospitals. For every 10 more proceduralist cases, patients had 4% lower adjusted odds of inpatient mortality (adjusted odds ratio, 0.96 [95% CI, 0.95–0.98], P<0.0001) and 3% greater adjusted odds of good outcome (adjusted odds ratio, 1.03 [95% CI, 1.02–1.04], P<0.0001). For every 10 more hospital cases, patients had 2% lower odds of inpatient mortality (adjusted odds ratio, 0.98 [95% CI, 0.98–0.99], P=0.0003) and 2% greater odds of good outcome (adjusted odds ratio, 1.02 [95% CI, 1.01–1.02], P<0.0001). With increasing volumes, there were higher odds of better outcomes. Nationally, higher proceduralist and hospital ST case volumes were associated with reduced inpatient mortality and better outcome. These data support volume requirements in guidelines for ST training and certification.

Value of Nomogram Incorporated Preoperative Tumor Volume and the Number of Postoperative Pathologically Lymph Node Metastasis Regions on Predicting the Prognosis of Thoracic Esophageal Squamous Cell Carcinoma.

BackgroundThe aim of this study was to explore the influence of preoperative tumor volume, length, maximum diameter and the number of postoperative pathologically lymph node metastasis (LNM) regions on survival prognosis of esophageal squamous cell carcinoma (ESCC) patients.MethodsA total of 296 patients with ESCC treated by standard curative esophagectomy were retrospectively analyzed. These patients were grouped for further analysis according to the optimal threshold of preoperative tumor volume, length, maximum diameter and the number of postoperative pathologically LNM regions. Kaplan–Meier method was used to calculate survival rate and survival comparison was performed by Log rank test. The Cox proportional hazards model was used to carry out univariate and multivariate analyses. Nomogram model was established by integrating statistically significant clinicopathological parameters, and the predictive value was further verified by calibration curve, concordance index (C-index) and decision curve.ResultsThe univariate and multivariate Cox regression analysis all showed that differentiation grade, TNM stage, adjuvant therapy, preoperative tumor volume and the number of post operative pathologically LNM regions were independent prognostic factors for PFS and OS (all P<0.05). The C-indexes of PFS and OS by nomograms were predicted to be 0.747 (95% CI: 0.717–0.777) and 0.732 (95% CI: 0.697–0.767), respectively, which were significantly higher than the 7th AJCC TNM stage, the C-indexes 0.612 (95% CI: 0.574–0.650) and 0.633 (95% CI: 0.595–0.671), separately. In addition, the calibration curves of nomogram models were highly consistent with actual observation for the five-year PFS and OS rate, and the decision curve analysis also showed that nomogram models had higher clinical application potentials than TNM staging model in predicting survival prognosis of thoracic ESCC after surgery.ConclusionThe nomograms incorporated preoperative tumor volume and the number of postoperative pathologically LNM areas are of great value in predicting survival prognosis of patients with thoracic ESCC.

The Potential of Asiatic Acid in the Reversion of Cyclophosphamide-Induced Hemorrhagic Cystitis in Rats.

The purpose of this study was to determine if asiatic acid may act efficiently in the model of cyclophosphamide (CYP)-induced cystitis in rats. We performed experiments after administration of CYP (single dose 200 mg/kg, intraperitoneally), asiatic acid (30 mg/kg/day for 14 consecutive days, by oral gavage), or CYP plus asiatic acid, during which conscious cystometry, measurements of urothelium thickness and bladder edema, as well as selected biomarkers analyses were conducted. In rats that received asiatic acid together with CYP, a drop in bladder basal pressure, detrusor overactivity index, non-voiding contraction amplitude, non-voiding contraction frequency, and the area under the pressure curve were observed, when compared to the CYP group. Furthermore, a significant increase in threshold pressure, voided volume, intercontraction interval, bladder compliance, and volume threshold to elicit NVC were found in that group accordingly. Administration of the asiatic acid successfully restored concentrations of biomarkers both in bladder urothelium (BDNF, CGRP, OCT-3, IL-1β, IL-6, NGF, nitrotyrosine, malondialdehyde, TNF-α, SV2A, SNAP23, SNAP25, PAC-1, ORM1, occludin, IGFBP-3, HB-EGF, T–H protein, Z01, and HPX) and detrusor muscle (Rho kinase and VAChT) in CYP-treated rats. Finally, asiatic acid significantly decreased urothelium thickness and bladder oedema. Asiatic acid proved to be a potent and effective drug in the rat model of CYP-induced cystitis.

Proclivity to Explore Locally Advanced Pancreas Cancer Is Not Associated with Surgeon Volume

Background and PurposeThere is limited high-level evidence to guide locally advanced pancreas cancer (LAPC) management. Recent work shows that surgeons’ preferences in LAPC management vary broadly. We sought to examine whether surgeon volume was associated with attitudes regarding LAPC management. MethodsAn electronic survey was distributed by email to an international cohort of pancreas surgeons to evaluate practice patterns regarding LAPC management. Clinical vignette-based questions evaluated surgeons’ attitudes regarding patient eligibility and the proclivity to offer exploration. Surgeons were classified into “low-“ or “high-volume” categories according to thresholds of self-reported annual pancreatectomy volume. Surgeon’s attitudes regarding LAPC management and inclination to consider exploration were compared across annual volume categories. ResultsA total of 153 eligible responses were received from 4 continents, for an estimated response rate of 10.6%. Median duration of practice was 12 years (IQR 6–20). Most respondents reported >25 cases/year (89, 58.2%), of which 34 (22.2%) reported >50. Compared to surgeons with <25 cases/year, surgeons with >25 cases/year practiced longer (median 15 vs. 7.5 years, P<0.001) and were more likely to “always” recommend neoadjuvant chemotherapy (83.2% vs. 56.3%, P=0.001). Surgeons performing >50 cases/year were more likely to offer arterial resection (70.6% vs. 43.7%, P=0.006). The willingness to offer (or defer) exploration did not differ across any categories of surgeons’ annual case volume. ConclusionsIn an international survey of pancreas surgeons, the proclivity to consider exploration for LAPC was not associated with multiple categories of surgeon volume. Better evidence is needed to define the optimal management approach to LAPC.

The prognostic role of optical coherence tomography in diabetic macular edema patients undergoing early dexamethasone implant shift.

To determine the prognostic characteristics of optical coherence tomography (OCT) parameters by evaluating diabetic macular edema (DME) patients with early dexamethasone (DEX) shift after three doses of intravitreal ranibizumab (RNB) injection. Fifty-four eyes of 34 patients who had DEX implant after three doses of RNB were included in this retrospective study. Early DEX shift includes patients who received direct DEX implant replacement after three doses of RNB load. Baseline OCT values and factors affecting best corrected visual acuity (BCVA) and central macular thickness (CMT) response were analyzed with logistic regression analyses. The presence of subretinal fluid and hyperreflective spot (HRS) >20 were found to be a negative predictive factor for anatomical response. (p = 0.009, p = 0.001, respectively) Low initial BCVA creates a positive effect on visual gain.( p = 0.041) Giant outer nuclear layer cysts, completely disrupted inner segment-outer segment and HRS > 20 have a negative effect on visual gain. (p = 0.025, p = 0.043, p = 0.023, respectively) According to the receiver operating characteristic analysis, the subretinal fluid volume threshold at which >20% reduction in CMT occurs was determined to be 0.85 mm3. (sensitivity 70%, specificity 84% area under the curve 0.817, p = 0.021). The presence of high number of HRS and high subretinal fluid volume at the baseline negatively affect prognosis even in patient groups with early DEX shift.

Optimal Threshold for the Volume–Outcome Relationship After Open AAA Repair in the Endovascular Era: Analysis of the International Consortium of Vascular Registries

As open abdominal aortic aneurysm (AAA) repair (OAR) rates decline in the endovascular era, the endorsement of minimum volume thresholds for OAR is increasingly controversial, as this may affect credentialing and training. The purpose of this analysis was to identify an optimal centre volume threshold that is associated with the most significant mortality reduction after OAR, and to determine how this reflects contemporary practice. This was an observational study of OARs performed in 11 countries (2010 – 2016) within the International Consortium of Vascular Registry database (n = 178 302). The primary endpoint was post-operative in hospital mortality. Two different methodologies (area under the receiving operating curve optimisation and Markov chain Monte Carlo procedure) were used to determine the optimal centre volume threshold associated with the most significant mortality improvement. In total, 154 912 (86.9%) intact and 23 390 (13.1%) ruptured AAAs were analysed. The majority (63.1%; n = 112 557) underwent endovascular repair (EVAR) (OAR 36.9%; n = 65 745). A significant inverse relationship between increasing centre volume and lower peri-operative mortality after intact and ruptured OAR was evident (p < .001) but not with EVAR. An annual centre volume of between 13 and 16 procedures per year was associated with the most significant mortality reduction after intact OAR (adjusted predicted mortality < 13 procedures/year 4.6% [95% confidence interval 4.0% – 5.2%] vs. ≥ 13 procedures/year 3.1% [95% CI 2.8% – 3.5%]). With the increasing adoption of EVAR, the mean number of OARs per centre (intact + ruptured) decreased significantly (2010 – 2013 = 35.7; 2014 – 2016 = 29.8; p < .001). Only 23% of centres (n = 240/1 065) met the ≥ 13 procedures/year volume threshold, with significant variation between nations (Germany 11%; Denmark 100%). An annual centre volume of 13 – 16 OARs per year is the optimal threshold associated with the greatest mortality risk reduction after treatment of intact AAA. However, in the current endovascular era, achieving this threshold requires significant re-organisation of OAR practice delivery in many countries, and would affect provision of non-elective aortic services. Low volume centres continuing to offer OAR should aim to achieve mortality results equivalent to the high volume institution benchmark, using validated data from quality registries to track outcomes.

Volume-outcome relationship for adrenalectomy: analysis of an administrative dataset for the Getting It Right First Time Programme.

A minimum volume threshold of at least six procedures per annum per surgeon has been set in UK and European guidelines for adrenal surgery. The aim of this study was to investigate outcomes for adrenal surgery in England relative to annual surgeon and hospital trust volume. Data were extracted from the Hospital Episodes Statistics database for England. A 6-year period (January 2013 to December 2018 inclusive) for all adult admissions for unilateral adrenal surgery was used. The primary outcome measure was an emergency readmission within 30 days of discharge following surgery. Procedures were categorized as open or minimally invasive surgery for analysis. Multilevel modelling was used to adjust for hierarchy and potential confounders. Data for 4189 adrenalectomies were identified. Only one third of surgeons (who operated on just over a half of all patients) performed at least six procedures in the year prior to the index procedure. For open surgery, emergency readmission rates fell significantly from 15.2 to 6.4 per cent for surgeons and from 13.2 to 6.1 per cent for trusts between the lowest- and highest-volume categories. Significant, but less dramatic falls were also seen for minimally invasive surgery. A volume-outcome effect was identified for adrenal surgery in England. Minimum volume thresholds should be set, although these may need to be more ambitious than the current threshold if outcomes are to be optimized. Surgery for disease of the adrenal gland can be complex. In many cases the skill and experience of the surgeon and the wider surgical team is thought to be important in determining the success of the procedure. The relative rarity of adrenal surgery means that there is little evidence to support this view. This study looked at outcomes for all 4189 patients who underwent adrenal surgery in England over a 6-year period. There was evidence that outcomes were better for patents when the surgeon and hospital trust had performed a larger number of adrenal surgery procedures in the year prior to the procedure. This was, however, dependent on which patient outcomes were studied and the type of procedure. These findings will inform the ongoing debate as to whether adrenal surgery in England should only be performed in regional centres by experienced teams.

Effect of ethanol extract of Punica granatum L against Freund’s complete adjuvant-induced arthritis in rats

Purpose: To investigate the protective effect of ethanol extract of P. granatum against arthritis in rat model.&#x0D; Methods: Twenty-six adult male Wistar rats (120 - 150 g) were separated into four groups (n = 6): normal control, arthritic control and two treatment groups. With the exception of normal control group, arthritis was induced by intraplantar administration of Freund’s complete adjuvant (FCA) on the 1st day of drug administration. The arthritic control group was not treated, while the treatment groups received extract orally at 500 or 750 mg/kg for the period of 4 weeks and at the end of each week, paw volume, thermal hyperalgesia, arthritic score and mechanical nociceptive threshold were performed to assess arthritis. Biochemical indicators and inflammatory cytokines in serum were determined using standard procedures.&#x0D; Results: There was significant decrease in paw volume and arthritic score; paw withdrawal latency was enhanced in extract-treated groups, compared to arthritic control group (p &lt; 0.05). Furthermore, ALT, AST and ALP levels, as well as RF and MDA activities decreased significantly with extract treatment, compared with arthritic control group (p &lt; 0.05). Treatment with the extract attenuated the altered level of interleukin 1β (IL-1β) and TNF-α levels in arthritic rats. Histological examination showed that treatment with the extract significantly reversed histological changes induced by arthritis.&#x0D; Conclusion: The results reveal that the beneficial effect of ethanol extract of P. granatum against FCAinduced arthritis is due to its ability to reduce the levels of inflammatory cytokines.

A Better Way to Assess Quality of TAVR Care in the U.S.

Quality of care in transcatheter aortic-valve replacement (TAVR) is currently measured by volume thresholds or arbitrarily chosen complications. These

The effects of microstructural parameters on the electrochemical properties of LSM-LSCF composite cathode by the particle-based discrete element method

In this paper, the particle packing-based discrete element method is applied to study the correlations between the microstructural parameters and electrochemical performances of LSM-LSCF composite electrodes. Firstly, through the verification of domain size independence and the comparison with the percolation theory, the computational domain size and effectiveness of the particle packing are determined. Then, the changes of the electrochemical reaction sites in the composite electrode with the LSM volume fraction under two different ratios of particle radius are investigated, including the LSM-LSCF-pore three-phase boundaries (TPBs) per electrode volume, TPBs per electrolyte surface, and percolated LSCF-pore double phase boundaries (DPBs). The distribution characteristics of the LSM-LSCF-pore TPBs within and outside the threshold volume fraction zone at different particle size ratio cases are obtained. When the particles are of equal radius, the formation of both percolated e−, O2−, and O2 transport paths is in the LSM volume fraction range of 0 to 0.7, due to the electronic conducting path is fully connected. The distribution characteristics of the LSCF-pore DPBs within the electrode in the percolation area and outside the percolation area are obtained respectively. This work is of great significance for the follow-up study of the physical and electrochemical processes within porous composite electrodes based on large-scale complex morphology.

QRS Duration During Follow-Up of Tetralogy of Fallot: How Valuable is it? Analysis of ECG Changes in Relation to Pulmonary Valve Implantation.

Long-term results after tetralogy of Fallot (TOF) repair are determined by the extent of right ventricular remodeling to chronic pulmonary regurgitation entailing progressive RV dysfunction and a risk of developing ventricular arrhythmia. Pulmonary valve replacement (PVR) can alleviate this burden. As a predictor of ventricular arrhythmia, QRS duration remains a strong parameter in this decision. We performed a retrospective analysis of all PVR patients between 2005 and 2018, studying the time evolution of electrocardiographic parameters before and after PVR through linear mixed model analysis. 42 TOF patients underwent PVR. The median timespan between primary repair and PVR was 18years (IQR 13-30). The indication for PVR was primarily based on the association of exercise intolerance (67%) and significant RV dilation on cMRI (median RVEDVi 161ml/m2 IQR 133-181). Median QRS length was 155ms (IQR 138-164), 4 (10%) patients had a QRS > 180ms. QRS duration increased significantly before PVR, but barely showed regression after PVR. Changes of QRS duration after PVR were independent of RV dilation. In conclusion, when the decision for PVR in TOF patients is primarily based on RV volume and/or function threshold, QRS duration > 180ms is rarely observed. In contrast with the significant increase of QRS duration before PVR, QRS length regression appears to be independent of the extent of RV dilation or QRS > 160ms. Considering that the decision for PVR is based on mechanical RV characteristics, the utility of serial follow-up of QRS duration in contemporary operated TOF patients becomes questionable in absence of clinical arguments for ventricular arrhythmia.

Are global gold futures returns volatilities and trading activities threshold cointegrated?

Purpose This study aims to examine whether global gold futures returns volatilities and trading activities are threshold cointegrated. Design/methodology/approach This study considers 11 gold futures markets, including 3 developed futures markets and 8 developing futures markets. This study also analyzes futures trading activities for speculators and hedgers. This study uses a nonlinear threshold vector error correction model (TVECM) and a threshold Lagrange multiplier (LM) test proposed by Hansen and Seo (2002). Findings The findings show that global gold futures return volatilities (FRV) and trading activities are not always threshold cointegrated. Most developed futures markets exhibit threshold cointegrated of gold FRV and trading activities for speculators and hedgers, whereas some developing futures markets exhibit threshold cointegrated. It suggests that speculators and hedgers trading activity conveys valuable information about changes in market volatility dynamics. On the other hand, responses to error-correction effect among gold FRV and trading activities for speculators and hedgers are dramatically different for developed and developing gold futures markets, respectively, particular in the unusual regime. Research limitations/implications Research results show that threshold cointegration between global gold FRV and trading activities matters but not always. Thus, threshold relations have improved the authors’ understanding of global gold futures price discovery process with a threshold. For research limitations, this study uses only near month futures contracts, as it contains more information but not using far month contracts. Practical implications The findings may have important trading implications with additional insights in a(n) (un)usual regime further regulation may be detrimental to the price responsiveness in futures markets if increased price volatility and trading volume are attributed to liquid and efficient markets. Social implications The findings may have important policy implications with additional insights. For example, in a(n) (un)usual regime greater regulatory restrictions may be warranted to decrease market inefficiencies if increased price fluctuations are caused by increased trading volume. Policymakers could enhance futures trading liquidity or restrict speculating positions. Originality/value This study examines whether global gold futures returns volatilities and trading activities are threshold cointegrated by using a nonlinear TVECM. The authors detect that some global gold futures returns volatilities and trading activities are threshold cointegrated but some are not. Hence, the findings determine whether the volatility–volume threshold relation holds across countries and investigate the determinants of cross-country differences in different traders.

The Impact of Center Volume on Outcomes in Lung Transplantation

BackgroundStudies in lung transplantation have shown variable association between hospital volume and clinical outcomes. We aimed to identify the pattern of effect of hospital volume on individual patient survival after lung transplantation. MethodsWe performed a retrospective analysis using the United Network for Organ Sharing national thoracic organ transplantation database. Adult patients who underwent lung transplantation between January 2013 and December 2017 were included. The association between mean annual center volume and 1-year overall survival was examined using restricted cubic splines in a random effects multivariable Cox model. The volume threshold for optimal 1-year overall survival was subsequently approximated by the maximum likelihood approach using segmented linear splines in the same model. ResultsThe study included 10,007 patients at 71 transplant centers. Median annual center volume was 22 cases (interquartile range, 10.6 to 38). A center volume threshold was identified at 33 cases per year (95% confidence interval, 28 to 37). Higher center volume, to 33 cases per year, was associated with better 1-year survival (hazard ratio 0.989, 95% confidence interval, 0.980 to 0.999 every additional case). Further increase in center volume above 33 cases per year showed no additional benefit (hazard ratio 1.000, 95% confidence interval, 0.996 to 1.003 every additional case). Twenty-three centers (32.4%) reached the volume threshold of 33 cases per year. ConclusionsOne-year survival after lung transplantation improved with increasing center volume to as many as 33 cases per year. Low volume centers below the 33 cases per year threshold had large variations in their outcomes and had a higher risk of performing poorly, although many of them maintained good performance.

Association of Infarct Volume Before Hemicraniectomy and Outcome After Malignant Infarction.

To determine the impact of infarct volume before hemicraniectomy in malignant middle cerebral artery infarction (MMI) as an independent predictor for patient selection and outcome prediction, we retrospectively analyzed data of 140 patients from a prospective multicenter study. Patients from the Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery (DESTINY) Registry who underwent hemicraniectomy after ischemic infarction of >50% of the middle cerebral artery territory were included. Functional outcome according to the modified Rankin Scale (mRS) was assessed at 12 months. Unfavorable outcome was defined as mRS score of 4 to 6. Infarct size was quantified semiautomatically from CT or MRI before hemicraniectomy. Subgroup analyses in patients fulfilling inclusion criteria of randomized trials in younger patients (age ≤60 years) were predefined. Among 140 patients with complete datasets (34% female, mean [SD] age 54 [11] years), 105 (75%) had an unfavorable outcome (mRS score >3). Mean (SD) infarct volume was 238 (63) mL. Multivariable logistic regression identified age (odds ratio [OR] 1.08 per 1-year increase, 95% confidence interval [CI] 1.02-1.13, p = 0.004), infarct size (OR 1.27 per 10-mL increase, 95% CI 1.12-1.44, p < 0.001), and NIH Stroke Scale score (OR 1.10, 95% CI 1.01-1.20, p = 0.030) before hemicraniectomy as independent predictors of unfavorable outcome. Findings were reproduced in patients fulfilling inclusion criteria of randomized trials in younger patients. Infarct volume thresholds for prediction of unfavorable outcome with high specificity (94% in overall cohort and 92% in younger patients) were >258 mL before hemicraniectomy. Outcome in MMI depends strongly on age and infarct size before hemicraniectomy. Standardized volumetry may be helpful in the process of decision-making concerning hemicraniectomy.

Optimal surgeon and hospital volume thresholds to reduce mortality and length of stay for CABG

ObjectiveWe used nationwide population-based data to identify optimal hospital and surgeon volume thresholds and to discover the effects of these volume thresholds on operative mortality and length of stay (LOS) for coronary artery bypass surgery (CABG).DesignRetrospective cohort study.SettingGeneral acute care hospitals throughout Taiwan.ParticipantsA total of 12,892 CABG patients admitted between 2011 and 2015 were extracted from Taiwan National Health Insurance claims data.Main Outcome MeasuresOperative mortality and LOS. Restricted cubic splines were applied to discover the optimal hospital and surgeon volume thresholds needed to reduce operative mortality. Generalized estimating equation regression modeling, Cox proportional-hazards modeling and instrumental variables analysis were employed to examine the effects of hospital and surgeon volume thresholds on the operative mortality and LOS.ResultsThe volume thresholds for hospitals and surgeons were 55 cases and 5 cases per year, respectively. Patients who underwent CABG from hospitals that did not reach the volume threshold had higher operative mortality than those who received CABG from hospitals that did reach the volume threshold. Patients who underwent CABG with surgeons who did not reach the volume threshold had higher operative mortality and LOS than those who underwent CABG with surgeons who did reach the volume threshold.ConclusionsThis is the first study to identify the optimal hospital and surgeon volume thresholds for reducing operative mortality and LOS. This supports policies regionalizing CABG at high-volume hospitals. Identifying volume thresholds could help patients, providers, and policymakers provide optimal care.

Analysis of the relationship between surgeon procedure volume and complications after total knee arthroplasty using a propensity-matched cohort study

ObjectivesThis study aimed to identify a threshold in annual surgeon volume associated with increased risk of revision (for any cause) and deep infection requiring surgery following primary elective total knee...

Complete fully automatic segmentation and 3-dimensional measurement of mediastinal lymph nodes for a new response evaluation criteria for solid tumors

We aimed to automatically detect and segment mediastinal lymph nodes, and to establish an objective method and reliable new response evaluation criteria to monitor the effectiveness of cancer treatment. The image processing techniques were applied and developed 3D measurement of the mediastinal lymph nodes based on automatic settings when segmenting the lymph node image. A repeatable and consistent lymph node evaluation system was created based on such features as the position of occurrence, grayness, and number of serial sections of lymph nodes. A total of 200 lymph node samples from Tri-Service General Hospital, Taiwan, were examined for statistical analysis. The proposed approach used weighted k-nearest neighbors for classification, achieving superior results with an accuracy and specificity of 97.5% and 99.4%, respectively. The volume of the lymph nodes was used as the reference index for tumor invasiveness evaluation. The error in the lymph node volume was 1.71% according to the verification results. Receiver operating characteristic (ROC) curves for each analysis were constructed and the area under the curve (AUC) was calculated with histopathology diagnosis as outcome for determining the optimal volume threshold of benign and malignant lymph nodes. It was observed that the lymph node volume was highly correlated with tumor invasion (p-value was less than 0.05). The experiment showed that the volume for the area under the ROC curve was 0.90 of tumor invasion evaluation. The lymph node volume was most effective in predicting tumor invasiveness, with the value 798.53 mm3 used as the standard for judging benignity and malignancy.

Upper Threshold for Resistance Training Volume in Trained Women-RETRACTION.

Medicine & Science in Sports & Exercise: June 2021 - Volume 53 - Issue 6 - p 1318 doi: 10.1249/MSS.0000000000002672

Pediatric subperiosteal orbital abscess characterization and prediction of size, location, and management

IntroductionSubperiosteal orbital abscess (SPOA) is a serious suppurative complication of pediatric sinusitis. The objective of this study is to stratify patient selection into those best treated medically versus surgically based on clinical outcomes. MethodsThis is a retrospective review of patients diagnosed with SPOA complicating sinusitis treated at a tertiary care pediatric hospital from 2002 through 2016. SPOA was diagnosed by CT scan. Characteristics evaluated include demographics, abscess size, location, and measurements, length of hospital stay, medical and surgical interventions, presenting symptoms, and complications. ResultsA total of 108 total SPOA secondary to sinusitis patients were included. A majority, 72.2%, were male with an average age at presentation of 6.8 years. The mean ± standard deviation abscess cubic volume was 0.98 ± 1.27 cm3 (median(range) = 0.44(0.01–7.34 cmcm3)). With an abscess volume of 0.510 cm3, there was a sensitivity of 71.2% and a specificity of 84.4% for needing surgical drainage. Those with large abscesses at our volume threshold were 13 times more likely to require surgery than those with small abscesses, OR: 13.41, 95%CI: 5.02–35.86, p < .001. Patients that required surgery had an abscess closer to the orbital apex with the majority, 25 (61.0%), being the most proximal to the apex, p = .004. The likelihood of surgery decreased with increased distance from the orbital apex in medial abscesses (OR:.92, 95%CI: 0.86-0.98, p = .009). ConclusionIn the pediatric population, SPOA is a serious consequence of sinusitis. This study provides evidence supporting that larger abscess size is a significant risk factor for requiring surgery. The appeal of our study is that it provides evidence and support that employ clinical parameters already assessed as standard practice in evaluating these patients. In summarizing the clinical translational relevance of our study, when determining whether to treat a patient with surgery and antimicrobial/medical therapy vs. non-surgical medical therapy alone, the clinician should focus on size of 0.510 cm3 or larger for abscesses in any location as a relative indication for surgery.

Small Pre-Implant LV Size Mediates Worse Post-Implant Outcomes in Female CF-LVAD Recipients

<h3>Purpose</h3> Females have an increased risk of post-operative right ventricular failure (RVF) and early 3-month mortality after LVAD implantation, however the underlying mechanisms are unclear. We hypothesize that LV size-LVAD pump speed mismatch driven by smaller LVEDDs in females results in shifting of the interventricular septum (IVS), which contributes to the sex-differences in outcomes post-LVAD. <h3>Methods</h3> In this translational study, we utilized clinical and bench-top approaches. Adult CF-LVAD recipients from the ISHLT Mechanically Assisted Circulatory Support (IMACS) registry (n=15,498, Implant years: 2013-17, age: 56 + 13 yrs, 21% female) were studied to determine association of female sex with outcomes of 3-month post-implant mortality and RVF (RVAD/ >14 days post-LVAD inotropes), with and without LVEDD in the models. On the benchtop, four bi-ventricular patient-specific silicone heart phantoms (LVEDD = 6.1, 6.3, 8.1, 8.3 cm) were subjected to variable bi-ventricular loading states (Δ volume = LV volume - RV volume), while observing IVS position. <h3>Results</h3> There were 1,466 deaths (9.5%) within 3 months of implant, and 2,550 patients (16.5%) with RVF. Female sex was associated with 42% increased odds of 3-month mortality (p<0.001), and 18% increased odds of RVF (p=0.005) post-LVAD. Females had a smaller pre-implant LVEDD than males (6.49 ± 1.08 vs 6.93 ± 1.32 cm, p<0.001). Smaller LVEDD was independently predictive of worse outcomes after LVAD (adjusted OR per cm decrease in LVEDD for mortality: 1.20, p<0.001; RVF: 1.09, p<0.001). Addition of LVEDD to the regression models attenuated the effect size of female sex on 3-month mortality post-LVAD by 14% and RVF by 13%. In the phantoms, the IVSs of the two smaller hearts (blue) were abnormally shifted to the left at smaller Δ volume compared to the IVSs of the two larger hearts (orange) (Figure 1). <h3>Conclusion</h3> Smaller LV size partially mediates worse post-LVAD outcomes for female patients, due to lower Δ volume thresholds for leftward shift of the IVS in smaller hearts.