Abstract Arteries exhibit a remarkable ability to adapt to diverse genetic defects and sustained alterations in mechanical loading. For example, changes in blood flow induced wall shear stress tend ...to control arterial caliber and changes in blood pressure induced circumferential wall stress tend to control wall thickness. We submit, however, that the axial component of wall stress plays a similarly fundamental role in controlling arterial geometry, structure, and function, that is, compensatory adaptations. This observation comes from a review of findings reported in the literature and a comparison of four recent studies from our laboratory that quantified changes in the biaxial mechanical properties of mouse carotid arteries in cases of altered cell-matrix interactions, extracellular matrix composition, blood pressure, or axial extension. There is, therefore, a pressing need to include the fundamental role of axial wall stress in conceptual and theoretical models of arterial growth and remodeling and, consequently, there is a need for increased attention to evolving biaxial mechanical properties in cases of altered genetics and mechanical stimuli.
Patients with locally advanced colon cancer have worse outcomes. Guidelines of various organizations are conflicting about the use of laparoscopic colectomy (LC) in locally advanced colon cancer. We ...determined whether patient outcomes of LC and open colectomy (OC) for locally advanced (T4) colon cancer are comparable in all colon cancer patients, T4a versus T4b patients, obese versus non-obese patients, and tumors located in the ascending, descending, and transverse colon. We used data from the 2013-2015 American College of Surgeons' National Surgical Quality Improvement Program. Patients were diagnosed with nonmetastatic pT4 colon cancer, with or without obstruction, and underwent LC (n = 563) or OC (n = 807). We used a composite outcome score (mortality, readmission, re-operation, wound infection, bleeding transfusion, and prolonged postoperative ileus); length of stay; and length of operation. Patients undergoing LC exhibited a composite outcome score that was 9.5% lower (95% CI - 15.4; - 3.5) versus those undergoing OC. LC patients experienced a 11.3% reduction in postoperative ileus (95% CI - 16.0; - 6.5) and an average of 2 days shorter length of stay (95% CI - 2.9; - 1.0). Patients undergoing LC were in the operating room an average of 13.5 min longer (95% CI 1.5; 25.6). We found no evidence for treatment heterogeneity across subgroups (p > 0.05). Patients with locally advanced colon cancer who receive LC had better overall outcomes and shorter lengths of stay compared with OC patients. LC was equally effective in obese/nonobese patients, in T4a/T4b patients, and regardless of the location of the tumor.
ObjectivesWe examined the utility of January 2004 to April 2014 Google Trends data from information searches for cancer screenings and preparations as a complement to population screening data, which ...are traditionally estimated through costly population-level surveys.SettingState-level data across the USA.ParticipantsPersons who searched for terms related to cancer screening using Google, and persons who participated in the Behavioral Risk Factor Surveillance System (BRFSS).Primary and secondary outcome measures(1) State-level Google Trends data, providing relative search volume (RSV) data scaled to the highest search proportion per week (RSV100) for search terms over time since 2004 and across different geographical locations. (2) RSV of new screening tests, free/low-cost screening for breast and colorectal cancer, and new preparations for colonoscopy (Prepopik). (3) State-level breast, cervical, colorectal and prostate cancer screening rates.ResultsCorrelations between Google Trends and BRFSS data ranged from 0.55 for ever having had a colonoscopy to 0.14 for having a Pap smear within the past 3 years. Free/low-cost mammography and colonoscopy showed higher RSV during their respective cancer awareness months. RSV for Miralax remained stable, while interest in Prepopik increased over time. RSV for lung cancer screening, virtual colonoscopy and three-dimensional mammography was low.ConclusionsGoogle Trends data provides enormous scientific possibilities, but are not a suitable substitute for, but may complement, traditional data collection and analysis about cancer screening and related interests.
Summary
Homozygous and compound heterozygous Miniature horses for ACAN alleles D1, D2, D3* and D4 exhibit chondrodysplastic dwarfism (OMIA 001271‐9796). In a previous study, the carrier rate for ...these four alleles, combined, was 26.2%. The purpose of this study was to investigate whether carriers of these dwarfism‐causing alleles had a shorter withers height than non‐carriers. A total of 245 Miniature horses were tested for these four ACAN alleles and also were measured for withers height. Of these horses, 98 were carriers and 147 were non‐carriers. A statistically significant difference of 1.43 inches was observed with the carriers being shorter (P = 1.72E − 11). The range of heights for the two groups overlapped, indicating that other factors, including genes, have an impact on withers height. However, the high carrier rate of these dwarfism‐causing variants may be due to selection for decreased height.
The structural protein elastin endows large arteries with unique biological functionality and mechanical integrity, hence its disorganization, fragmentation, or degradation can have important ...consequences on the progression and treatment of vascular diseases. There is, therefore, a need in arterial mechanics to move from materially uniform, phenomenological, constitutive relations for the wall to those that account for separate contributions of the primary structural constituents: elastin, fibrillar collagens, smooth muscle, and amorphous matrix. In this paper, we employ a recently proposed constrained mixture model of the arterial wall and show that prestretched elastin contributes significantly to both the retraction of arteries that is observed upon transection and the opening angle that follows the introduction of a radial cut in an unloaded segment. We also show that the transmural distributions of elastin and collagen, compressive stiffness of collagen, and smooth muscle tone play complementary roles. Axial prestresses and residual stresses in arteries contribute to the homeostatic state of stress in vivo as well as adaptations to perturbed loads, disease, or injury. Understanding better the development of and changes in wall stress due to individual extracellular matrix constituents thus promises to provide considerable clinically important insight into arterial health and disease.
The continuing lack of longitudinal histopathological and biomechanical data for human arteries in health and disease highlights the importance of studying the many genetic, pharmacological, and ...surgical models that are available in mice. As a result, there has been a significant increase in the number of reports on the biomechanics of murine arteries over the past decade, particularly for the common carotid artery. Whereas most of these studies have focused on wild-type controls or comparing controls vs. a single model of altered hemodynamics or vascular disease, there is a pressing need to compare results across many different models to understand more broadly the effects of genetic mutations, pharmacological treatments, or surgical alterations on the evolving hemodynamics and the microstructure and biomechanical properties of these vessels. This paper represents a first step toward this goal, that is, a biomechanical phenotyping of common carotid arteries from control mice and seven different mouse models that represent alterations in elastic fiber integrity, collagen remodeling, and smooth muscle cell functionality.
Abstract Intraluminal exposure of the infrarenal aorta to porcine pancreatic elastase represents one of the most commonly used experimental models of the development and progression of abdominal ...aortic aneurysms. Morphological and histological effects of elastase on the aortic wall have been well documented in multiple rodent models, but there has been little attention to the associated effects on mechanical properties. In this paper, we present the first biaxial mechanical data on, and associated nonlinear constitutive descriptors of, the effects of elastase on the infrarenal aorta in mice. Quantification of the dramatic, acute effects of elastase on wall behavior in vitro is an essential first step toward understanding the growth and remodeling of aneurysms in vivo, which depends on both the initial changes in the mechanics and the subsequent inflammation-mediated turnover of cells and extracellular matrix that contributes to the evolving mechanics.
Background
We compared patient outcomes of robot-assisted surgery (RAS) and laparoscopic colectomy without robotic assistance for colon cancer or nonmalignant polyps, comparing all patients, obese ...versus nonobese patients, and male versus female patients.
Methods
We used the 2013–2015 American College of Surgeons National Surgical Quality Improvement Program data to examine a composite outcome score comprised of mortality, readmission, reoperation, wound infection, bleeding transfusion, and prolonged postoperative ileus. We used propensity scores to assess potential heterogeneous treatment effects of RAS by patient obesity and sex.
Results
In all, 17.1% of the 10,844 of patients received RAS. Males were slightly more likely to receive RAS. Obese patients were equally likely to receive RAS as nonobese patients. In comparison to nonRAS, RAS was associated with a 3.1% higher adverse composite outcome score. Mortality, reoperations, wound infections, sepsis, pulmonary embolisms, deep vein thrombosis, myocardial infarction, blood transfusions, and average length of hospitalization were similar in both groups. Conversion to open surgery was 10.1% lower in RAS versus nonRAS patients, but RAS patients were in the operating room an average of 52.4 min longer.
We found no statistically significant differences (p > 0.05) by obesity status and gender.
Conclusions
Worse patient outcomes and no differential improvement by sex or obesity suggest more cautious adoption of RAS.
Abstract Quantifying the time course of load-induced changes in arterial wall geometry, microstructure, and properties is fundamental to developing mathematical models of growth and remodeling. ...Arteries adapt to altered pressure and flow by modifying wall thickness, inner diameter, and axial length via marked cell and matrix turnover. To estimate particular biomaterial implications of such adaptations, we used a 4-fiber family constitutive relation to quantify passive biaxial mechanical behaviors of mouse carotid arteries 0 (control), 7–10, 10–14, or 35–56 days after an aortic arch banding surgery that increased pulse pressure and pulsatile flow in the right carotid artery. In vivo circumferential and axial stretches at mean arterial pressure were, for example, 11% and 26% lower, respectively, in hypertensive carotids 35–56 days after banding than in normotensive controls; this finding is consistent with observations that hypertension decreases distensibility. Interestingly, the strain energy W stored in the carotids at individual in vivo conditions was also less in hypertensive compared with normotensive carotids. For example, at 35–56 days after banding, W was 24%, 39%, and 47% of normal values at diastolic, mean, and systolic pressures, respectively. The energy stored during the cardiac cycle, W sys – W dias , also tended to be less, but this reduction did not reach significance. When computed at normal in vivo values of biaxial stretch, however, W was well above normal for the hypertensive carotids. This net increase resulted from an overall increase in the collagen-related anisotropic contribution to W despite a decrease in the elastin-related isotropic contribution. The latter was consistent with observed decreases in the mass fraction of elastin.
Purpose
Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new, palliative approach for patients with peritoneal surface malignancies (PSMs). Its main goals are to control symptoms and ...ascites. For this experimental procedure, treatment efficacy and patient safety need to be closely monitored.
Methods
We performed a prospective registry study for patients with PSMs. Cisplatin (C) (7.5 mg/m
2
body surface) and doxorubicin (D) (1.5 mg/m
2
) were administered laparoscopically via PIPAC.
Results
Between November 2015 and June 2020, we recorded data from 108 patients and 230 scheduled procedures. Tumor burden, patient fitness, quality of life, operating time and in-hospital stay remained stable over consecutive procedures. We recorded 21 non-access situations and 14 intraoperative complications (11 intestinal injuries, and three aspirations while inducing anesthesia). Three or more previous abdominal surgeries or cytoreductive surgery (CRS) with intraperitoneal hyperthermic chemoperfusion (HIPEC) were risk factors for non-access and intestinal injuries (χ
2
,
p
≤ 0.01). Five Grade IV and three Grade V postoperative complications according to the Clavien–Dindo Classification (CDC) occurred. Median overall survival was 264 days (interquartile range 108–586). Therapies were primarily discontinued because of death (34%), progressive (26%), or regressive (16%) disease.
Conclusion
PIPAC is effective in stabilizing PSMs and retaining quality of life in selected patients. Earlier abdominal surgeries and CRS with HIPEC should be considered when determining the indication for PIPAC. Randomized controlled studies are needed to evaluate PIPAC’s therapeutic benefits compared to systemic chemotherapy (sCHT) alone.
Trial registration
NCT03100708 (April 2017).
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