Socioeconomic status as a predictor of post-operative mortality and outcomes in carotid artery stenting vs. carotid endarterectomy.

Background: The association between low socioeconomic status (SES) and worse surgical outcomes has become an emerging area of interest. Literature has demonstrated that carotid artery stenting (CAS) poses greater risk of postoperative complications, particularly stroke, than carotid endarterectomy (CEA). This study aims to compare the impact of low SES on patients undergoing CAS vs. CEA. Methods: The National Inpatient Sample (NIS) was queried for patients undergoing CAS and CEA from 2010 to 2015. Patients were stratified by highest and lowest median income quartiles by zip code and compared through demographics, hospital characteristics, and comorbidities defined by the Charlson Comorbidity Index (CCI). Primary outcome was in-hospital mortality. Secondary outcomes included acute kidney injury (AKI), post-operative stroke, sepsis, and bleeding requiring reoperation.Multivariable logistic regression was used to determine the effect of SES on outcomes. Results: Five thousand four hundred twenty-five patients underwent CAS (Low SES: 3,516 (64.8%); High SES: 1,909 (35.2%) and 38,399 patients underwent CEA (Low SES: 22,852 (59.5%); High SES: 15,547 (40.5%). Low SES was a significant independent predictor of mortality [OR = 2.07 (1.25-3.53); p = 0.005] for CEA patients, but not for CAS patients [OR = 1.21 (CI 0.51-2.30); p = 0.68]. Stroke was strongly associated with low SES, CEA patients (Low SES = 1.5% vs. High SES = 1.2%; p = 0.03), while bleeding was with high SES, CAS patients (Low SES = 5.3% vs. High SES = 7.1%; p = 0.01). CCI was a strong predictor of mortality for both procedures [CAS: OR1.45 (1.17-1.80); p < 0.001. CEA: OR1.60 (1.45-1.77); p < 0.001]. Advanced age was a predictor of mortality post-CEA [OR = 1.03 (1.01-1.06); p = 0.01]. While not statistically significant, advanced age and increased mortality trended towards a positive association in CAS [OR = 1.05 (1.00-1.10); p = 0.05]. Conclusions: Low SES is a significant independent predictor of post-operative mortality in patients who underwent CEA, but not CAS. CEA is also associated with higher incidence of stroke in low SES patients. Findings demonstrate the impact of SES on outcomes for patients undergoing carotid revascularization procedures. Prospective studies are warranted to further evaluate this disparity.

Early Discharge After Minimally Invasive Aortic and Mitral Valve Surgery.

BACKGROUND: We investigated patient outcomes in relation to their postoperative length of stay after minimally invasive valve surgery. METHODS: All adults who survived elective, uncomplicated minimally invasive aortic or mitral valve surgery at a single center between 2012 and 2019 were classified by postoperative length of stay: early discharge (≤3 days) or late discharge (>3 days). The trend in early discharge was investigated over the study period, predictors of early discharge were identified using multivariate logistic regression modeling, and 1:1 propensity score matching was used to determine which patients in the late-discharge cohort had similar health to patients discharged early. Adjusted outcomes of 30-day mortality, readmission, and direct costs were analyzed. RESULTS: Among 1262 consecutive patients undergoing minimally invasive valve surgery, 618 were elective and uncomplicated, 25% (n = 162) of whom were discharged early. The proportion of early-discharge patients increased over time (P for trend < .05). A history of congestive heart failure, stroke, or smoking and higher Society of Thoracic Surgeons predictive risk of mortality score negatively predicted early discharge (P < .05). Propensity score matching identified 101 (22%) late-discharge patients comparable with early-discharge patients. Adjusted 30-day mortality and readmission rates were comparable between cohorts. The median direct costs per patient ($20,046 vs $22,124, P < .05) were significantly lower in the early-discharge cohort. CONCLUSIONS: In well-selected patients early discharge after minimally invasive valve surgery was associated with lower costs but comparable postoperative outcomes. About one-fifth of patients who remain in the hospital beyond postoperative day 3 may be candidates for earlier discharge.

Optic Nerve Head Measurements With Optical Coherence Tomography: A Phantom-Based Study Reveals Differences Among Clinical Devices.

PURPOSE: Optical coherence tomography (OCT) can monitor for glaucoma by measuring dimensions of the optic nerve head (ONH) cup and disc. Multiple clinical studies have shown that different OCT devices yield different estimates of retinal dimensions. We developed phantoms mimicking ONH morphology as a new way to compare ONH measurements from different clinical OCT devices. METHODS: Three phantoms were fabricated to model the ONH: One normal and two with glaucomatous anatomies. Phantoms were scanned with Stratus, RTVue, and Cirrus clinical devices, and with a laboratory OCT system as a reference. We analyzed device-reported ONH measurements of cup-to-disc ratio (CDR) and cup volume and compared them with offline measurements done manually and with a custom software algorithm, respectively. RESULTS: The mean absolute difference between clinical devices with device-reported measurements versus offline measurements was 0.082 vs. 0.013 for CDR and 0.044 mm3 vs. 0.019 mm3 for cup volume. Statistically significant differences between devices were present for 16 of 18 comparisons of device-reported measurements from the phantoms. Offline Cirrus measurements tended to be significantly different from those from Stratus and RTVue. CONCLUSIONS: The interdevice differences in CDR and cup volume are primarily caused by the devices' proprietary ONH analysis algorithms. The three devices yield more similar ONH measurements when a consistent offline analysis technique is applied. Scan pattern on the ONH also may be a factor in the measurement differences. This phantom-based study has provided unique insights into characteristics of OCT measurements of the ONH.

Retina-simulating phantom for optical coherence tomography.

Optical coherence tomography (OCT) is a rapidly growing imaging modality, particularly in the field of ophthalmology. Accurate early diagnosis of diseases requires consistent and validated imaging performance. In contrast to more well-established medical imaging modalities, no standardized test methods currently exist for OCT quality assurance. We developed a retinal phantom which mimics the thickness and near-infrared optical properties of each anatomical retinal layer as well as the surface topography of the foveal pit. The fabrication process involves layer-by-layer spin coating of nanoparticle-embedded silicone films followed by laser micro-etching to modify the surface topography. The thickness of each layer and dimensions of the foveal pit are measured with high precision. The phantom is embedded into a commercially available, water-filled model eye to simulate ocular dispersion and emmetropic refraction, and for ease of use with clinical OCT systems. The phantom was imaged with research and clinical OCT systems to assess image quality and software accuracy. Our results indicate that this phantom may serve as a useful tool to evaluate and standardize OCT performance.

Multilayer thin-film phantoms for axial contrast transfer function measurement in optical coherence tomography.

In optical coherence tomography (OCT), axial resolution is one of the most critical parameters impacting image quality. It is commonly measured by determining the point spread function (PSF) based on a specular surface reflection. The contrast transfer function (CTF) provides more insights into an imaging system's resolving characteristics and can be readily generated in a system-independent manner, without consideration for image pixel size. In this study, we developed a test method for determination of CTF based on multi-layer, thin-film phantoms, evaluated using spectral- and time-domain OCT platforms with different axial resolution values. Phantoms representing six spatial frequencies were fabricated and imaged. The fabrication process involved spin coating silicone films with precise thicknesses in the 8-40 µm range. Alternating layers were doped with a specified concentration of scattering particles. Validation of layer optical properties and thicknesses were achieved with spectrophotometry and stylus profilometry, respectively. OCT B-scans were used to calculate CTFs and results were compared with convetional PSF measurements based on specular reflections. Testing of these phantoms indicated that our approach can provide direct access to axial resolution characteristics highly relevant to image quality. Furthermore, tissue phantoms based on our thin-film fabrication approach may have a wide range of additional applications in optical imaging and spectroscopy.