Chronic venous insufficiency (CVI) affects >40% of the U.S. population; thus, intervention for symptomatic venous disease comprises a large portion of many vascular practices. The treatment of ...superficial CVI has evolved from open surgical treatment to minimally invasive endovenous closure, including both thermal and nonthermal techniques. Thrombotic complications of thermal ablation have been well reported, with an overall complication rate of <2%. However, a paucity of high-powered, real-world data is available on the thrombotic outcomes of nonthermal techniques. In the present study, we compared the incidence of endovenous heat-induced thrombosis (EHIT) and endovenous glue-induced thrombosis (EGIT) in a large cohort of patients with CVI.
A retrospective review was conducted at two tertiary-level institutions of patients who had undergone superficial endovenous ablation from 2018 to 2021. The patient demographics, comorbidities, and periprocedural outcomes were collected through medical record review. A Caprini risk assessment model score was assigned using the information available from the electronic medical records. The patients were categorized by procedure type (ClosureFast Medtronic Inc, Minneapolis, MN radiofrequency ablation RFA vs VenaSeal Medtronic Inc cyanoacrylate glue closure CAG). The primary end point was the incidence of EHIT or EGIT. The secondary end point was the incidence of deep vein thrombosis and/or pulmonary embolism.
A total of 803 patients had undergone 1096 procedures during the study period. Their mean age was 62 ± 15 years, and 67% were women. Of the 1096 procedures, 700 were RFA and 396 were CAG procedures, with a combined closure rate of 98% by postprocedure duplex ultrasound at 7 days. The average Caprini score was 5.2 ± 1.8 (RFA, 5.0; vs CAG, 5.4; P < .001). The incidence of EHIT and EGIT was 1.9% and 1.3%, respectively (P = .57). The deep vein thrombosis rate was 0.1% in the RFA cohort and 0.3% in the CAG cohort (P = .81). A comparative analysis of thermal vs nonthermal techniques was performed. A univariate analysis of the risk factors for EHIT and EGIT revealed no significant factors predisposing to thrombotic events.
The results from the present study have demonstrated the safety of RFA and CAG closure techniques for CVI, with lower thrombotic rates than previously reported. Further work might help to identify how these results can be achieved across all venous ablative techniques for CVI, even for patient populations with advanced venous disease and possibly a greater than average risk of thrombotic events.
Aromatic stacks formed through self-assembly are promising building blocks for the construction of molecular electronic devices with adjustable electronic functions, in which noncovalently bound ...π-stacks act as replaceable modular components. Here we describe the electron-transport properties of single-molecule aromatic stacks aligned in a self-assembled cage, using scanning probe microscopic and break junction methods. Same and different modular aromatic pairs are noncovalently bound and stacked within the molecular cage holder, which leads to diverse electronic functions. The insertion of same pairs induces high electronic conductivity (10–3–10–2 G 0, G 0 = 2e 2/h), while different pairs develop additional electronic rectification properties. The rectification ratio was, respectively, estimated to be 1.4–2 and >10 in current–voltage characteristics and molecular orientation-dependent conductance measurements at a fixed bias voltage. Theoretical calculations demonstrate that this rectification behavior originates from the distinct stacking order of the internal aromatic components against the electron-transport direction and the corresponding lowest unoccupied molecular orbital conduction channels localized on one side of the molecular junctions.
Bowl-shaped π-conjugated compounds, or buckybowls, are a novel class of sp2-hybridized nanocarbon materials. In contrast to tubular carbon nanotubes and ball-shaped fullerenes, the buckybowls feature ...structural flexibility. Bowl-to-bowl structural inversion is one of the unique properties of the buckybowls in solutions. Bowl inversion on a surface modifies the metal–molecule interactions through bistable switching between bowl-up and bowl-down states on the surface, which makes surface-adsorbed buckybowls a relevant model system for elucidation of the mechano-electronic properties of nanocarbon materials. Here, we report a combination of scanning tunneling microscopy (STM) measurements and ab initio atomistic simulations to identify the adlayer structure of the sumanene buckybowl on Au(111) and reveal its unique bowl inversion behavior. We demonstrate that the bowl inversion can be induced by approaching the STM tip toward the molecule. By tuning the local metal–molecule interaction using the STM tip, the sumanene buckybowl exhibits structural bistability with a switching rate that is two orders of magnitude faster than that of the stochastic inversion process.
By use of the reversible trimerization of boronic acids, the series of boroxine cages 3-mer, 6-mer, and 12-mer were constructed from rationally designed diboronic acids whose bond angles between two ...C–B bonds are 60°, 84°, and 117°, respectively. Boroxine cages 6-mer and 12-mer have 1.5 and 2.5 nm sized cavities, respectively.
Biases and gender disparities influence career pathways within medicine, and vascular surgery is no exception. Venous disease comprises an estimated 1% to 3% of total health care expenditures. ...However, its value among vascular surgeons is poorly understood. This study aims to investigate the factors that influence vascular surgeons' current perceptions of superficial and deep venous disease treatments.
An anonymous survey was distributed electronically to practicing vascular surgeons in December 2021. The respondents were stratified by gender and practice breakdown. A venous-heavy practice was defined as a practice with venous work comprising ≥25% of the total volume. Changes in practice patterns over the respondent's career were also explored. Descriptive, univariate, and multivariate analyses were performed using STATA (StataCorp).
A total of 315 practicing vascular surgeons responded, with 81.5% from the United States. Their mean age was 46.6 ± 9.6 years, and most identified as men (63.3%). The race and ethnicity breakdown was as follows: White (non-Hispanic), 63.0%; Asian or Asian Indian, 17.1%; Hispanic, Latinx, or Spanish, 8.4%; Black, 1.6%; and unknown, 9.9%. The practice settings were academic for 47.0%, private practice for 26.5%, hospital employed for 23.3%, and other for 3.2%. The female respondents were significantly younger (P < .0001), with fewer years in practice (P < .0001) and were more likely to perceive a gender bias within a career encompassing venous disease compared with the male respondents (P = .02). Of the 315 participants, 143 (45.4%) had a venous-heavy practice. No differences were found in age or gender between the venous-heavy and venous-light practices. Those with a venous-heavy practice had significantly more years in practice statistically (P = .02), had sought more venous training after graduation (P < .0001), were more likely to be in private practice (P < .0001), and were more likely to desire a practice change (P = .001) compared with those with a venous-light practice. Overall, 74.3% of respondents indicated that venous work might be less “valued” than arterial work in the field of vascular surgery. On multivariable regression, the predictors for the perception of venous work being less valued were female gender (odds ratio, 2.01; 95% confidence interval, 1.14-4.03) and completion of a vascular surgery fellowship (odds ratio, 2.0; 95% confidence interval, 1.15-3.57).
Vascular surgeons overwhelmingly perceived the management of venous disease to be of less value than that of arterial disease, particularly by women and fellowship-trained vascular surgeons. The prevalence of venous disease, as measured by its proportion of the U.S. healthcare budget, cannot be overstated. Thus, efforts to elevate the importance of chronic venous disease within the scope of vascular surgery practices are essential to ensure patients are provided with appropriate specialty care.
A single molecular resistive (conductance) switch via control of anchoring positions was examined by using a molecule consisting of more than two same anchors. For this purpose, we adopted the ...covered quaterthiophene (QT)-based molecular wire junction. The QT-based wire consisted of two thiophene ring anchors on each side; thus, shift of anchors was potentially possible without a change in the binding modes and distortion of the intramolecular structure. We observed three distinct conductance states by using scanning tunneling microscope-based break junction technique. A detailed analysis of the experimental data and first-principles calculations revealed that the mechanism of the resistive switch could be explained by standard length dependence (exponential decay) of conductance. Here, the length is the distance between the anchoring points, i.e., length of the bridged π-conjugated backbone. Most importantly, this effective tunneling length was variable via only controlling the anchoring positions in the same molecule. Furthermore, we experimentally showed the possibility of a dynamic switch of anchoring positions by mechanical control. The results suggested a distinct strategy to design functional devices via contact engineering.
The organometallic Ru molecular wires 1-3 Ru(PR3)4(Ctriple bond, length as m-dashCC5H5N)2 (PR3)4 = (dppe)2 (1), P(OMe3)4 (2), and (dmpe)2 (3) show significantly higher conductance compared to their ...organic counterpart, 1,4-dipyridyl butadiyne (4). CV and UV-Vis measurements and DFT calculations suggest that the high-lying HOMOs of the Ru wires are the key factor for the high conductance.
Delayed referral of venous ulcers increases resource usage Kiguchi, Misaki M.; Reynolds, Kyle B.; Biagetti, Gina M. ...
Journal of vascular surgery. Venous and lymphatic disorders (New York, NY),
January 2022, 2022-01-00, 20220101, Letnik:
10, Številka:
1
Journal Article
Venous insufficiency is often not readily recognized as a contributing etiology to nonhealing wounds by nonvascular surgery specialists, potentially delaying appropriate treatment to achieve wound ...healing and increasing healthcare costs. The objective of the present study was to understand the time and resources used before the definitive treatment of venous ulcers.
A single-institution retrospective medical record review of C6 patients undergoing radiofrequency saphenous and perforator vein ablation from May 2016 to January 2018 identified 56 patients with 67 diseased limbs. The numbers of inpatient, emergency department, and wound care visits and the intervals to vein ablation from the initial evaluation of the ulceration by a healthcare provider were collected. The demographics, comorbidities, previous venous interventions, wound characteristics, duplex ultrasound imaging, and available wound healing follow-up through July 2018 were assessed for all patients.
For the 67 limbs examined, 588 total healthcare visits were performed for wound assessment before a referral to a vascular surgeon, with 413 visits at a wound care center (70% of all visits). Other specialty visits included emergency medicine (17.9% of limbs) and rheumatology (22.4% of limbs). Six patients (nine limbs) were admitted to inpatient services for treatment of their ulceration. Overall, the patients were seen an average of 8.6 ± 9.7 times for their ulcer with the wound center before determination of a contributing venous etiology and subsequent treatment. These visits translated to a median of 230 days (interquartile range, 86.5-1088 days) between the first identification of the ulcer by healthcare providers and subsequent accurate diagnosis and definitive treatment of their venous disease with radiofrequency saphenous and perforator vein ablation. After intervention, 18.64% of the limbs had healed at 1 month, 33.92% had healed at 3 months, 50% had healed at 6 months, and 82.92% had healed by 12 months.
An earlier and accurate diagnosis of the venous contribution to ulcers and subsequent appropriate treatment of venous etiologies in wound formation by a vascular venous specialist could significantly improve healing and minimize resource usage.
The influence of hydrothermal treatment (HTT) on the hemicellulose, i.e. glucomannan/galactoglucomannan (GM/GGM) and arabinoglucurono-xylan (AGX) in Japanese cedar was examined using mild ...temperatures (95 °C and 120 °C) for its kiln drying. Based on infrared spectra, only a slight change due to HTT was observed in the hemicellulose chemical structure. The quantitative changes of the major chemical components including lignin, cellulose, and hemicellulose also exhibited slight differences among samples. However, the molecular chain-length composition of GM/GGM and AGX in the cell walls decreased clearly with HTT, as well as with an increase in temperature. Also, it was found that the strength of the interaction between cellulose and hemicellulose molecules such as GM/GGM and AGX in cell walls decreased depending on the increase in HTT temperature. These results showed that the polymeric structure of GM/GGM and AGX was degraded by hydrolysis at 95 °C of HTT and proceeded further at 120 °C of HTT.
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