Operative Candidates Research Articles

Cross-Sectional Analysis of Patients Referred to a Tertiary Lymphatic Surgery Center.

Secondary lymphedema has become an increasingly common reason for referral to plastic surgery. Understanding referral patterns for lymphedema patients is crucial to optimizing care. Patients referred to plastic surgery for lymphedema at a lymphatic surgery center between January 2016 and 2023 were identified. Primary outcomes of interest included clinical lymphedema staging and characteristics, patient demographics, and referral sources. Secondary outcomes were prior lymphedema treatment, agreement between referring provider and plastic surgeon's diagnosis, and patient disposition after surgical evaluation. Descriptive statistics and multivariate logistic regression analysis were performed. A total of 285 patients with extremity edema were referred to plastic surgery; 60.0% of patients had prior malignancy, 45.6% of patients had undergone a prior lymph node procedure, and 40% had received radiation, while 56.8% of patients had previously seen occupational therapy. Body mass index (BMI, OR 1.09, p = 0.013), age (OR 1.25, p = 0.005), and prior physical oroccupational therapy (OR 1.23, p = 0.011) were associated with later stages of lymphedema upon presentation, while prior radiation (OR 0.79, p = 0.006) and malignancy (OR 0.85, p = 0.034) were associated with earlier stages of lymphedema. Self-referral (27.4%), primary care (17.9%), and medical oncology (14.7%) were the most common referral sources. Lymphedema was confirmed in 68.1% of referrals, and 28.5% of these patients proceeded to surgery. Patients were more likely to be operative candidates if referred by primary care (RR 2.1, p = 0.006) or occupational therapy (RR 4.6, p = 0.010). Referred patients ultimately undergo lymphedema surgery at relatively low rates, indicating that most referred patients are not ideal surgical candidates. Optimizing referral patterns through multidisciplinary education may enhance the referral process and improve access to lymphedema surgery.

Risk of mortality in patients requiring reoperative open-heart surgery

BackgroundImprovements in surgical techniques and perioperative care as well as increased patient life expectancies have led cardiothoracic surgeons to perform more complex operations, including reoperative open-heart surgeries. However, there is debate as to which patients are appropriate operative candidates for reoperative procedures. MethodsThis is a retrospective, single-center study of patients who underwent reoperative open-heart surgery via median sternotomy or thoracotomy over a 10-year period. Patients with previous ventricular assist device or heart transplant were excluded. Patients were stratified by age <65 years compared with age ≥65 years for analysis. Survival was assessed using Kaplan-Meier curves and log-rank tests. Multivariate analysis was performed with Cox proportional hazards regression. ResultsA total of 250 patients underwent reoperative open-heart surgery at our center from 2012 to 2022. In total, 176 patients underwent valve surgery, 53 underwent coronary artery bypass grafting, 31 underwent aortic surgery, and 29 underwent other operations. The overall mortality rate was 13.6% at 30 days and 21.2% at 1-year postoperatively. Patients ≥65 years old had a greater average survival compared with patients <65 years old (5.0 vs 4.1 years, P = .046). However, there were no differences in survival by age when patients were stratified by procedure, either coronary artery bypass grafting (P = .29) or valve surgery (P = .16). On multivariate analysis, reoperative valve surgery, intraoperative use of extracorporeal membrane oxygenation, and a greater number of reoperative surgeries were associated with lower survival. ConclusionPatients undergoing reoperative open-heart surgery are clinically complex and had lower survival with each subsequent reoperation.

Hexagonal Boron Nitride Quantum Simulator: Prelude to Spin and Photonic Qubits.

The quest for qubit operation at room temperature is accelerating the field of quantum information science and technology. Solid state quantum defects with spin-optical properties are promising spin- and photonic qubit candidates for room temperature operations. In this regard, a single boron vacancy within hexagonal boron nitride (h-BN) lattice such as VB- defect has coherent quantum interfaces for spin and photonic qubits owing to the large band gap of h-BN (6 eV) that can shield a computational subspace from environmental noise. However, for a VB- defect in h-BN to be a potential quantum simulator, the design and characterization of the Hamiltonian involving mutual interactions of the defect and other degrees of freedom are needed to fully understand the effect of defects on the computational subspace. Here, we studied the key coupling tensors such as zero-field splitting, Zeeman effect, and hyperfine splitting in order to build the Hamiltonian of the VB- defect. These eigenstates are spin triplet states that form a computational subspace. To study the phonon-assisted single photon emission in the VB- defect, the Hamiltonian is characterized by electron-phonon interaction with Jahn-Teller distortions. A theoretical demonstration of how the VB- Hamiltonian is utilized to relate these quantum properties to spin- and photonic-quantum information processing. For selecting promising host 2D materials for spin and photonic qubits, we present a data-mining perspective based on the proposed Hamiltonian engineering of the VB- defect in which h-BN is one of four materials chosen to be room temperature qubit candidates.

A and B Site Doped Barium Niobates with Improved Electrical Properties of Electrochemical Oxidative Coupling of Methane

Electrochemical oxidative coupling of methane (E-OCM) to produce ethylene is gaining renewed interest due the ability to control the conversion rate and product selectivity though temperature and applied potential. We previously demonstrate Mg, Fe and Ca, Fe codoped barium niobates have remarkable methane activation properties coupled with good chemical stability. Nevertheless, their electrical conductivity remained less than 50 mScm-1 that is low for electrode application. Hence, we attempted both A and B site doping on barium niobates with various dopants such as Sr, La (A site), and Ca, Mg, Fe, Co, Ni, Y (B site) to improve their electrical properties. These doped niobates showed enhanced thermochemical stability in SOFC relevant conditions and catalytic activity towards methane activation. The redox behavior of the Nb4+/5+ couple seem to be at a key reason behind this redox stability while the size and electronegativity of the dopants affect the electrical properties. The chemical stability was analyzed by TGA measurements followed by analysis of the perovskite powders using PXRD measurements. Impedance measurements under difference gas environments were utilized to analyze their electrical conductivity. Chronoamperometric measurements were utilized to evaluate the E-OCM properties of these catalysts. Our results demonstrate doped barium niobates as a promising candidate for stable operation in high temperature electrochemical applications. References H. Denoyer, A. Benavidez, A. Brearley, K. P. Ramaiyan*, F. H. Garzon*, “Electrochemical oxidative coupling of methane: deciphering the exceptional properties of BaMg0.33Nb0.67-xFexO3-δ for enhanced electrocatalysis and durable operation” Under revision J. Electrochem. Soc, (December 2023).H. Denoyer, A. Benavidez, F. H. Garzon*, K. P. Ramaiyan*, “Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene” Adv. Mater. Interfaces, 2022, 2200796 (1-9). Ramaiyan, L. H. Denoyer, A. Benavidez, F. H. Garzon*, “Role of Dopants in Fine-Tuning the Electrical and Catalytic Properties of Barium Niobate Perovskites Towards High-Temperature Electrolyzer Application” ECS Transactions 2023, 111, 1139.H. Denoyer, A. Benavidez, A. Brearley, K. Ramaiyan, F. H. Garzon*, “Chemical Stability of BaMg0.33Nb0.67-XFexO3-δ in High Temperature Methane Conversion Environments” ECS Transactions, 2023, 111, 587.

Antena Dwi Port Dwi Pengutuban Bulat terinspirasi Bahan Meta untuk Sistem Komunikasi Satelit Kecil

This paper presents a dual circular polarized C-band patch antenna for a small satellite communication system The antenna consists of two different annular patch structure with three split ring resonators. The antenna is designed considering space environment and the smallest form of satellite structure. The antenna is fabricated space qualified substrate material Rogers 5880 with overall dimension of 85.22× 48.59 × 1.575 mm3. The antenna achieves circular polarization at 5.1 GHz and 5.2 GHz frequency for port 2 and port 1, respectively. The split ring resonator structures contribute to enhance antenna gain and axial beamwidth. Realized gain of 7.29 dB and 7.33 dB are achieved at 5.1 GHz and 5.2 GHz operating frequency with 3dB axial beamwidth of 170 ̊ and 153 ̊ , respectively. Antenna size and performance show that the antenna can be a potential candidate for smooth operation of small satellite communication system.

Pancreaticoduodenectomy in high-grade pancreatic and duodenal trauma

IntroductionHigh-grade pancreaticoduodenal injuries are highly morbid and may require complex surgical management. Pancreaticoduodenectomy (Whipple procedure) is sometimes utilized in the management of these injuries, but guidelines on its use are lacking. This paper aims to present our 14-year experience in management of high-grade pancreaticoduodenal injuries at our busy, urban trauma center. MethodsA retrospective review was performed on patients (ages >15 years) presenting with high-grade (AAST-OIS Grades IV and V) injuries to the pancreas or duodenum at our Southeastern Level 1 trauma center. Inclusion criteria included high-grade injury and requirement of Whipple procedure based on surgeon discretion. Patients were divided into two groups: (1) those who underwent Whipple procedures during the index operation and (2) Whipple candidates. Whipple candidates included patients who received Whipples in a staged fashion or who would have benefited from the procedure but either died or were salvaged to another procedure. Demographics, injury patterns, management, and outcomes were compared. Primary outcome was survival to discharge. ResultsOf 66,272 trauma patients in this study period, 666 had pancreatic or duodenal injuries, and 20 met inclusion criteria. Of these, 6 had Whipples on the index procedure and 14 were Whipple candidates (among whom 7 had staged Whipples, 6 died before completing a Whipple, and 1 was salvaged). Median (IQR) age was 28 (22.75–40) years. Patients were 85 % male, 70 % Black. GSWs comprised 95 % of injuries. All patients had at least one concomitant injury, most commonly major vascular injury (75 %), colonic injury (65 %), and hepatic injury (60 %). In-hospital mortality among Whipple patients was 15 %. ConclusionsComplex pancreaticoduodenal injuries requiring pancreaticoduodenectomy are rare but life-threatening. In such patients, hemorrhage was the leading cause of death in the first 24 h. Approximately half underwent damage control surgery with staged Whipple Procedures. However, pancreaticoduodenectomy at the initial operation is feasible in highly selective patients, depending on the extent of injury, physiologic status, and resuscitation.

Spin-Lattice Relaxation and Spin-Phonon Coupling of ns1 Metal Ions at the Surface.

To use transition metal ions for spin-based applications, it is essential to understand fundamental contributions to electron spin relaxation in different ligand environments. For example, to serve as building blocks for a device, transition metal ion-based molecular qubits must be organized on surfaces and preserve long electron spin relaxation times, up to room temperature. Here we propose monovalent group 12 ions (Zn+ and Cd+) as potential electronic metal qubits with an ns1 ground state. The relaxation properties of Zn+ and Cd+, stabilized at the interface of porous aluminosilicates, are investigated and benchmarked against vanadium (3d1) and copper (3d9) ions. The spin-phonon coupling has been evaluated through DFT modeling and found to be negligible for the ns1 states, explaining the long coherence time, up to 2 μs, at room temperature. These so far unexplored metal qubits may represent viable candidates for room temperature quantum operations and sensing.

Decoupled differentiable graph neural architecture search

The differentiable graph neural architecture search (GNAS) effectively designs graph neural networks (GNNs) efficiently and automatically with excellent performance based on different graph data distributions. Given a GNN search space containing multiple GNN component operation candidates, the differentiable GNAS method builds a mixed supernet using learnable architecture parameters multiplied by the GNN component operation candidates. When the mixed supernet completes optimization, the mixed supernet is pruned based on the best architecture parameters to efficiently identify the optimal GNN architecture in the GNN search space. However, the multiplicative relationship between the architecture parameters and the GNN component operation candidates introduces a coupled optimization bias into the weight optimization process of the mixed supernet GNN component operation candidates. This bias results in differentiable GNAS performance degradation. To solve the problem of coupled optimization bias in the previous differentiable GNAS method, we propose the Decoupled Differentiable Graph Neural Architecture Search (D2GNAS). It utilizes the Gumbel distribution as a bridge to decouple the weights optimization of supernet GNN component candidate operation and architecture parameters for constructing the decoupled differentiable GNN architecture sampler. The sampler is capable of selecting promising GNN architectures based on architecture parameters treated as sampling probabilities, and it is further optimized through the validation gradients derived from the sampled GNN architectures. Simultaneously, D2GNAS builds a single-path supernet with a pruning strategy to compress the supernet progressively to improve search efficiency further. We conduct extensive experiments on multiple benchmark graphs. The experimental findings demonstrate that D2GNAS outperforms all established baseline methods, both manual GNN and GNAS methods, in terms of performance. Additionally, D2GNAS has a lower time complexity than previous differentiable GNAS methods. Based on the fair GNN search space, it achieves an average 5x efficiency improvement. Codes are available at https://github.com/AutoMachine0/D2GNAS.

Cost-effectiveness of Rapid On-site Evaluation During Navigational Bronchoscopy

BackgroundPeripheral pulmonary lesions (PPL) are common, with more than 1.6 million PPLs incidentally identified in the United States annually. Navigational bronchoscopy (NB) is a cornerstone of the diagnostic evaluation of PPLs. Intraprocedural rapid on-site evaluation (ROSE) of biopsies obtained during NB is widely used, but the data for its utility are contradictory. The cost-effectiveness of ROSE has yet to be established and as such, ROSE currently has variable implementation between institutions and is not adequately reimbursed by payors. Research QuestionIs ROSE cost-effective during NB for PPL from a third-party payor perspective? Study Design and MethodsA cost-effectiveness model was constructed comparing NB for PPL with versus without ROSE from a third-party payor perspective. The base case is a 60-year-old operative candidate with a 2 cm pulmonary nodule without radiographic mediastinal or hilar lymphadenopathy referred for NB. Cost per quality adjusted life-year gained was the primary outcome. Inputs for the model were estimated from published literature. One-way deterministic sensitivity analyses were conducted on all parameters. Probabilistic sensitivity analysis was performed. ResultsThe use of ROSE resulted in a gain of 0.01 quality-adjusted life years and cost an additional $466. At a willingness to pay (WTP) threshold of $100,000/life-year, ROSE was cost-effective with an incremental cost effectiveness ratio (ICER) of $44,465.88. Sensitivity analyses on the sensitivity of NB with and without ROSE show that ROSE must increase the diagnostic sensitivity of the procedure by 3% to become cost-effective. InterpretationThe use of ROSE during navigational bronchoscopy for PPL is cost-effective for third-party payors at a WTP threshold of $100,000/life year and should be reimbursed at a higher rate. The cost-effectiveness of ROSE hinges on the additional diagnostic sensitivity gained by using ROSE.

A Green High-k Dielectric from Modified Carboxymethyl Cellulose-Based with Dextrin.

Many crucial components inside electronic devices are made from non-renewable, non-biodegradable, and potentially toxic materials, leading to environmental damage. Finding alternative green dielectric materials is mandatory to align with global sustainable goals. Carboxymethyl cellulose (CMC) is a bio-polymer derived from cellulose and has outstanding properties. Herein, citric acid, dextrin, and CMC based hydrogels are prepared, which are biocompatible and biodegradable and exhibit rubber-like mechanical properties, with Young modulus values of 0.89 MPa. Hence, thin film CMC-based hydrogel is explored as a suitable green high-k dielectric candidate for operation at low voltages, demonstrating a high dielectric constant of up to 78. These fabricated transistors reveal stable high capacitance (2090 nF cm-2) for ≈±3V operation. Using a polyelectrolyte-type approach and poly-(2-vinyl anthracene) (PVAn) surface modification, this study demonstrates a thin dielectric layer (d ≈30 nm) with a small voltage threshold (Vth ≈-0.8 V), moderate transconductance (gm ≈65 nS), and high ON-OFF ratio (≈105). Furthermore, the dielectric layer exhibits stable performance under bias stress of ± 3.5 V and 100 cycles of switching tests. The modified CMC-based hydrogel demonstrates desirable performance as a green dielectric for low-voltage operation, further highlighting its biocompatibility.

Locoregional Therapies for Hepatobiliary Tumors: Contemporary Strategies and Novel Applications.

A large majority of primary hepatobiliary tumors are hepatocellular carcinomas (HCC), with the remainer being cholangiocarcinoma. While surgical resection remains the gold standard treatment for hepatobiliary tumors, relatively few patients are operative candidates, and systemic treatments have limited effectiveness. Locoregional therapies offer significant promise in the management of HCC. Ablation and radioembolization may offer similar outcomes to surgery for early-stage hepatocellular carcinoma while radioembolization and chemoembolization are valuable in the management of advanced disease. There is significantly less evidence for the role of locoregional therapy in the treatment of cholangiocarcinoma, although it appears to be well tolerated.

A decade of experience with minimally invasive anti-reflux operations: robot vs. LESS.

The increasing use of robotic systems for anti-reflux operations prompted this study to evaluate and compare the efficacy of robotic and Laparo-Endoscopic Single-Site (LESS) approaches. From 2012, 228 robotic fundoplication and 518 LESS fundoplication patients were prospectively followed, analyzing perioperative metrics. Data are presented as median (mean ± SD); significance at p ≤ 0.05. Patients undergoing a robotic vs. LESS fundoplication were 67 (64 ± 13.7) vs. 61 (59 ± 15.1) years-old with BMIs of 25 (25 ± 3.2) vs. 26 (25 ± 3.9) kg/m2 (p = 0.001 and 1.00, respectively). 72% of patients who underwent the robotic approach had a previous abdominal operation(s) vs 44% who underwent the LESS approach (p = 0.0001). 38% vs. 8% had a re-operative fundoplication (p = 0.0001), 59% vs. 45% had a type IV hiatal hernia (p = 0.0004). Operative duration was 160 (176 ± 76.7) vs. 130 (135 ± 50.5) min (p = 0.0001). There were 0 (robotic) vs. 5 (LESS) conversions to a different approach (p = 0.33). 5 Patients vs. 3 patients experienced postoperative complications (p = 0.06), and length of stay (LOS) was 1 (2 ± 2.6) vs. 1 (1 ± 3.2) days (p = 0.0001). Patient symptomatic dysphagia preoperatively for the robotic vs. LESS approach was scored as 2 (2.4 ± 1.9) vs. 1 (1.9 ± 1.6). Postoperatively, symptomatic dysphagia was scored as 1 (1.5 ± 1.6) vs. 1 (1.7 ± 1.7). The change in these scores was - 1 (- 1 ± 2.2) vs. 0 (- 0.5 ± 2.2) (p = 0.004). Despite longer operative times and LOS in older patients, the robotic approach is efficient in undertaking very difficult operations, including patients with type IV or recurrent hiatal hernias. Furthermore, preoperative anti-reflux operations were more likely to be undertaken with the robotic approach than the LESS approach. The patient's postoperative symptomatic dysphagia improved relatively more than after the LESS approach. The vast majority of patients who underwent the LESS approach enjoyed improved cosmesis, thus, making LESS a stronger candidate for more routine operations. Despite patient selection bias, the robotic and LESS approaches to anti-reflux operations are safe, efficacious, and should be situationally utilized.

Analysis of Field Data Using Microsoft Excel and MATLAB Software to Evaluate Reservoir and Well Damage

Reservoir formation damage is a drop in a well's productivity caused by a decrease in reservoir rock permeability. To tackle this issue and maximize well production, obtained pressure build-up time data at a steady production rate from a vertical producing oil WELL 20A, was analysed to establish the wellbore and reservoir characteristics. A numerical well test simulator (Matlab) is used to simulate damage in the area close to the wellbore, a Microsoft Excel sheet and an analytical approach to calculate the impact of wellbore and reservoir factors such as skin, wellbore storage, and average reservoir permeability. In order to determine whether the numerical well test simulator was successful at performing pressure transient analysis on observed data, the findings from the analytical solutions using Microsoft Excel Sheet and numerical well test simulator Matlab were compared. Comparable outcomes for the permeability and skin values were obtained from the build-up test data analysis generated; hence, the negative skin values for wells 20A acquired after the analysis suggest that the formation is not damaged. This indicate that well 20A is not a candidate for workover operations.

Open-heart surgery in patients with cirrhosis: Variables associated with survival outcomes

BackgroundUnderstanding the risks of performing open-heart surgery in patients with cirrhosis is of critical importance given increased risks of morbidity and mortality. We analyzed the variables and risk scoring systems associated with survival and postoperative outcomes among patients with cirrhosis after open-heart surgery. MethodsThis is a single-center retrospective study of 32 patients with cirrhosis who underwent open-heart surgery at our institution between August 2020 – September 2022. Patients were stratified by mortality status to compare demographic and clinical variables. Survival was assessed using Kaplan-Meier curves and log-rank tests for the following variables: Model for End-Stage Liver Disease (MELD) score (<11 vs ≥11), Child-Turcotte-Pugh (CTP) class (A vs B vs C), Society of Thoracic Surgeons (STS) score (predicted mortality <4 vs 4 to 8 vs ≥8), European System for Cardiac Operative Risk Evaluation (EuroSCORE) II (<3.3 vs ≥3.3), and cardiopulmonary bypass (off pump vs on pump). ResultsOverall survival for our patient cohort was 93.8% at 30 days, 81.3% at 1 year, and 78.1% at 2 years postoperatively. Increased preoperative creatinine (p = 0.049), preoperative total bilirubin (p = 0.017), intraoperative blood products (p = 0.016), and intensive care unit length of stay (p = 0.001) were significantly associated with decreased survival. Among the risk scoring systems, only CTP class was significantly associated with survival (p < 0.0001). ConclusionsWe demonstrated high short-term and long-term survival among patients with cirrhosis after open-heart surgery, suggesting that select patients may be operative candidates. Among risk-scoring systems, only CTP was significantly associated with survival, which may guide future risk stratification strategies.

ASSESSMENT OF PATIENTS' QUALITY OF LIFE AFTER DAVID SURGERY

Modern cardiac surgery increasingly requires rapid physical and mental rehabilitation of the patient. Today, more and more attention is paid to the peculiarities of psycho-emotional indicators in patients who are planned or have undergone surgical interventions. The quality of life of patients after David's operation for aneurysm of the root and ascending aorta remains unexplored. The aim: assessment of the quality of life of patients with aortic aneurysm who underwent David's valve-preserving operation. Materials and methods. From December 2015 to April 2023, 38 patients were operated on using the technique of aortic valve reimplantation with direct Dacron prosthesis "David" and 40 patients with prosthetic aortic valve and ascending aorta "Bentall operation". The mean age of patients was 46.97 ± 12.2 years in group 1 and 52.08 ± 12.08 in group 2, respectively. The share of men is 92.1% in group 1 and 97.5% in group 2. The average observation period is 31.89 ± 22.42 months. Results.Not a single fatal case was recorded within 30 days of the postoperative period. The percentage of survival after the observation period is 97.36% in group 1 and 92.5% in group 2. We analyzed the quality of life of all patients according to eight scales: physical functioning (PH), role functioning (RP), pain intensity (BP), general health (GH), vital activity (VT), social functioning (SF), emotional condition (RE) and mental health (MH). When analyzing patient questionnaires in the scale of physical functioning, we calculated a sufficiently high indicator, which was 94.59 ± 6.71% in group 1 and 79.5% ± 8.46% in group 2. On all other scales, there was also an advantage in the group patients who underwent David's operation. Conclusions. From the obtained results, it can be stated that patients after David's operation in the medium term have excellent physical and mental health indicators and are completely adapted to daily life compared to the results after Bentall's operation. David's valve-sparing operation, especially in isolated, planned situations, ensures normal functioning of the aortic valve with no regurgitation. This operation can be performed with very low rates of complications and postoperative mortality. Thus, in our center, all patients with aortic root aneurysms are potential candidates for valve-sparing operations.

Real-time, chirped-pulse heterodyne detection at room temperature with 100 GHz 3-dB-bandwidth mid-infrared quantum-well photodetectors

Thanks to intrinsically short electronic relaxation on the ps time scale, III-V semiconductor unipolar devices are ideal candidates for ultrahigh-speed operation at mid-infrared frequencies. In this work, antenna-coupled, GaAs-based multi-quantum-well photodetectors operating in the 10–11 µm range are demonstrated, with a responsivity of 0.3 A/W and a 3-dB-cutoff bandwidth of 100 GHz at room temperature. The frequency response is measured up to 220 GHz: beyond 100 GHz we find a roll-off dominated by the 2.5-ps-long recombination time of the photo-excited electrons. The potential of the detectors is illustrated by setting up an experiment where the time dependent emission frequency of a quantum cascade laser operated in pulsed mode is measured electronically and in real time, over a frequency range &gt;60GHz. By exploiting broadband electronics, and thanks to its high signal-to-noise ratio, this technique allows the acquisition, in a single-shot, of frequency-calibrated, mid-infrared molecular spectra spanning up to 100 GHz and beyond, which is particularly attractive for fast, active remote sensing applications in fields such as environmental or combustion monitoring.

Long-term prognostic value of [15O]H2O PET imaging in patients suspected for cerebral hemodynamic insufficiency

ObjectivesQuantitative regional cerebral perfusion (rCBF) measurements using [15O]H2O PET with arterial cannulation and acetazolamide (ACZ) challenge have been reserved to identify high-risk patients that are candidates for by-pass operation. We aimed to assess the prognostic value of various parameters in quantitative [15O]H2O PET measurements in patients not subsequently undergoing surgery. MethodsWe identified 32 eligible patients who underwent [15O]H2O brain PET imaging for suspicion of hemodynamic insufficiency between 2009 and 2020. Cerebrovascular events were defined as new ischemic lesions on MRI, stroke, transient ischemic attack, vascular dementia. Follow-up period was 91 months (range: 26-146). rCBF before (rCBFbase) and after (rCBFacz) ACZ challenge and the relative increase (CVR), were examined in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral artery territories of the affected hemisphere, and the most recent MRI scans were scored for infarcts and white matter lesions. ResultsReceiver operating characteristic (ROC) curve analysis showed higher prognostic accuracy for rCBFacz(AUC:0.82) compared to CVR (AUC:0.72) and rCBFbase (AUC:0.77). ROC AUC, optimal thresholds (and corresponding sensitivity/specificity/accuracy) for rCBFacz after ACZ in individual territories were 0.79 and 37.8 mL 100g−1 min−1 (0.81/0.63/0.72) for the ACA, 0.84 and 32 mL 100g−1 min−1 (0.81/0.75/0.78) for the MCA, and 0.70 and 43.9 ml/(mL 100g−1 min−1 (0.81/0.43/0,62) for the PCA. Kaplan Meier survival curve showed longer event-free survival in patients with rCBFacz below cut-off (p=0.007). In multivariate analysis rCBFacz remained a significant predictor when correcting for age. ConclusionQuantitative rCBF measurements after ACZ challenge with [15O]H2O PET provided high prognostic value for future cerebrovascular events.

Post-Face Lift Facial Paralysis: A 20-Year Experience.

Facial nerve (FN) injury during a face lift is a relatively rare but potentially devastating complication. Despite extensive literature discussing FN anatomy and danger zones, few studies describe detailed management, FN exploration intraoperative findings, and outcome after post-face lift facial paralysis (PFFP). The authors reviewed a 20-year experience in managing iatrogenic PFFP. Patients with PFFP were retrospectively identified between 2002 and 2022. Demographic data, operative details from the face lift procedure, facial function after face lift, medical and surgical management, intraoperative findings, and long-term outcomes were analyzed. A total of 25 patients who experienced PFFP were referred for evaluation over the past 20 years. Eight patients required FN exploration, 6 of whom underwent nerve repair; all recovered to some degree, with 50% achieving essentially normal facial function. Fourteen patients underwent nonsurgical management, including physical therapy, chemodenervation, and filler therapy. Of these nonsurgical patients who were not lost to follow-up, 50% achieved normal facial function and 42% achieved nearly normal facial function. The single patient who had no spontaneous improvement presented outside the reinnervation window and was not an operative candidate. PFFP outcome depends on injury type and location, accurate assessment, and appropriate treatment; however, the overall prognosis is favorable. FN exploration is warranted when nerve transection is suspected. Observation is suitable for patients demonstrating early signs of recovery. Patients presenting beyond a reasonable reinnervation window will need other facial reanimation techniques. When FN exploration is required, outcomes may be superior in a facial nerve center setting. Adjunctive interventions for symmetry improvement while awaiting recovery are available. Therapeutic, IV.

Incidence of Underreferral to Multidisciplinary Evaluation in Severe Primary Mitral Regurgitation

BackgroundSevere primary mitral regurgitation (MR) warrants multidisciplinary evaluation involving cardiac surgeons and structural interventional cardiologists. The incidence and potential impact on outcomes of missed evaluation remain unknown. MethodsWe conducted a retrospective cohort study of patients with new diagnoses of severe primary MR from an echocardiography database within a large health care network. Of 37,749 unique patients with echocardiograms, 126 had severe primary MR. We compared the 2-year survival of patients who did and did not undergo multidisciplinary evaluation. Propensity score matching was performed on the basis of The Society of Thoracic Surgeons Predicted Risk of Mortality for mitral repair. ResultsOf 126 patients with severe primary MR (median age, 79 years [interquartile range, 68-89 years]; 60% women), 37 (29%) underwent multidisciplinary evaluation. Evaluated patients were younger (71 [58-79] years vs 84 [73-90] years), and of those, 26 (70%) underwent operations within 37 days of evaluation. The Society of Thoracic Surgeons Predicted Risk of Mortality median was 1% (1%-5%) and 4% (1%-10%) for evaluated and unevaluated patients, respectively. Of the 74 patients matched, the mortality rate was lower in evaluated patients at 90 days (11% [n = 4] vs 27% [n = 10]; P = .08) and 2 years (16% [n = 6] vs 35% [n = 13]; P = .06). ConclusionsThe multidisciplinary referral rate for newly identified severe primary MR was low at 29%, with underreferral of low-risk, potentially operative candidates. The observed improved survival with multidisciplinary evaluation calls for efforts to maximize referral of this group of patients.

Workspace, Singularity, and Dexterity Analyses of a Six-Degrees-of-Freedom SDelta Robot With an Orthogonal Base Platform

Abstract The SDelta is a three-limb, six-degrees-of-freedom parallel kinematics machine, a pertinent candidate for high-speed operations by virtue of its simple architecture. The original design of the SDelta includes a planar base and moving platforms. Here, we propose a novel architecture for an improved SDelta, the orthogonal SDelta (OSD), with a cube-shaped orthogonal base platform. Inverse and forward position models are reported, along with singularity and dexterity analyses. Moreover, design parameters and mechanical constraints leading to a singularity-free workspace are provided. An evaluation of the system translational workspace and orientational capability, upon consideration of volume and dexterity, is included. The SDelta as well as a generic 6SPS mechanism (C, P, and S denote, respectively, the cylindrical, prismatic, and spherical kinematic pairs, the actuated pair is represented underlined, as P) are designed with the same parameters, then the performance of the SDelta, the OSD, and the 6SPS mechanisms are being compared. The results show that the orientational capability of the OSD is better than those of the 6SPS and the SDelta. Furthermore, the OSD has an average condition number of 2.9 over its translational workspace and 1.69 over a predefined effective regular workspace, which make the OSD a good candidate for operations that need both a high orientational capability and high dexterity.