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Objective: Decision-making regarding level of lower extremity amputation is sometimes challenging. Selecting an appropriate anatomic level for major amputation requires consideration of tradeoffs between postoperative function and risk of wound complications that may require additional operations, including debridement and/or conversion to above-knee amputation (AKA). We evaluated the utility of common, non-invasive diagnostic tests used in clinical practice to predict the need for reoperations among patients undergoing primary, elective, below knee-amputations (BKAs) by vascular surgeons., Methods: Patients undergoing elective BKA over a 5-year period were identified using Current Procedural Terminology codes. Medical records were reviewed to characterize demographics, pre-amputation testing transcutaneous oxygen tension (TcPO 2 ), and ankle-brachial index (ABI). The need for ipsilateral post-BKA reoperation (including BKA revision and/or conversion to AKA) regardless of indication was the primary outcome. Associations were evaluated using univariable and multivariable logistic regression models. Cutpoints for TcPO 2 values associated with amputation reoperation were evaluated using receiver operating characteristic curves., Results: We identified 175 BKAs, of which 46 (26.3%) required ipsilateral reoperation (18.9% BKA revisions and 14.3% conversions to AKA). The mean age was 63.3 ± 14.8 years. Most patients were male (65.1%) and White (72.0%). Mean pre-amputation calf TcPO 2 was 40.0 ± 20.5 mmHg, and mean ABI was 0.64 ± 0.45. In univariable models, post-BKA reoperation was associated with calf TcPO 2 (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.94-0.99; P = .013) but not ABI (OR, 0.53; 95% CI, 0.19-1.46; P = .217). Univariable associations with reoperation were also identified for age (OR, 0.97; 95% CI, 0.94-0.990; P = .003) and diabetes (OR, 0.43; 95% CI, 0.21-0.87; P = .019). No associations with amputation revision were identified for gender, race, end-stage renal disease, or preoperative antibiotics. Calf TcPO 2 remained associated with post-BKA reoperation in a multivariable model (OR, 0.97; 95% CI, 0.94-0.99; P = .022) adjusted for age (OR, 0.98; 95% CI, 0.94-1.01; P = .222) and diabetes (OR, 0.98; 95% CI, 0.94-1.01; P = .559). Receiver operating characteristic analysis suggested a TcPO 2 ≥38 mmHg as an appropriate cut-point for assessing risk for BKA revision (area under the curve = 0.682; negative predictive value, 0.91)., Conclusions: Reoperation after BKA is common, and reoperation risk was associated with pre-amputation TcPO 2 . For patients undergoing elective BKA, higher risk of reoperation should be discussed with patients with an ipsilateral TcPO 2  <38 mmHg., Competing Interests: Disclosures None., (Copyright © 2024 Society for Vascular Surgery. All rights reserved.)

Objective: To determine the rate of emergency versus elective lower extremity amputations in the United States., Background: Lower extremity amputation is a common endpoint for patients with poorly controlled diabetes and multilevel peripheral vascular disease. Although the procedure is ideally performed electively, patients with limited access may present later and require an emergency operation. To what extent rates of emergency amputation for lower extremities vary across the United States is unknown., Methods: Evaluation of Medicare beneficiaries who underwent lower extremity amputation between 2015 and 2020. The rate was determined for each zip code and placed into rank order from lowest to highest rate. We merged each beneficiary's place of residence and location of care with the American Hospital Association Annual Survey using Google Maps Application Programming Interface to determine the travel distance for patients to undergo their procedure., Results: Of 233,084 patients, 66.3% (154,597) were men, 69.8% (162,786) were White. The average age (SD) was 74 years (8). There was wide variation in rates of emergency lower extremity amputation. The lowest quintile of zip codes demonstrated an emergency amputation rate of 3.7%, whereas the highest quintile demonstrated 90%. The median travel distance in the lowest emergency surgery rate quintile was 34.6 miles compared with 10.5 miles in the highest quintile of emergency surgery ( P < 0.001)., Conclusions: There is wide variation in the rate of emergency lower extremity amputations among Medicare beneficiaries, suggesting variable access to essential vascular care. Travel distance and rate of amputation have an inverse relationship, suggesting that barriers other than travel distance are playing a role., Competing Interests: S.H.A.D. receives funding from The Fredrick A. Coller Surgical Society and is a postdoctoral fellow on grant 1T32AG062403 from the National Institute on Aging. C.A.P. also receives funding from the NIA on grant 1T32AG062403. M.A.C. receives funding from the United States Food and Drug Administration, the Vascular Cures Foundation, and Carelon Medical Benefits Management as the Vascular Expert Advisory Panelist. Also, he serves on the Vascular Expert Advisory Panel for AIM Specialty Health, Inc. A.M.I. receives funding from the Agency for Healthcare Research and Quality as a principal investigator on grant R01-HS028606 and a co-investigator on grant R18-HS028963. He also received funding from the National Institute of Diabetes and Digestive and Kidney Disease as a co-principal investigator on grant R01-DK137466. Also, he is a Principal at HOK architects, a global design and architecture firm. The remaining author reports no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Phlebectomy of large voluminous varicose veins comes with a risk of substantial blood loss. The purpose of the present study was to investigate the outcomes associated with the use of an adjunct tourniquet during varicose vein surgery of complex and large truncular varicosities., Methods: The prospectively collected registry data included anatomic and outcomes details for patients who presented with complex and large truncular varicosities with a CEAP clinical class of C2, or higher (indicating more serious venous disease) from December 2014 to December 2021. Of all patients, those treated with an adjunct tourniquet for large complex varicosities (largest diameter varicosity ≥1 cm by visual inspection) were selected for analysis. The venous clinical severity scores (VCSSs) and patient-reported outcomes (PROs) were obtained. Additional parameters, including operative time, tourniquet time, and blood loss, were obtained retrospectively via a review of the medical records. Univariate descriptive statistics of the demographic and procedural data were performed pre- and postoperatively, with comparisons performed using the Student two-tailed t test., Results: The data from 19 patients (22 limbs; 7 women and 12 men) were analyzed. Of the 22 limbs, 11 (50%) had advanced venous disease of C4 or higher preoperatively. A review of the preoperative duplex ultrasound scans confirmed the presence of large varicosities (average, 1.0 ± 0.54 cm; n = 18). All the limbs were treated using radiofrequency ablation of axial reflux and phlebectomy (a combination of powered and stab) under tourniquet control (82%) or phlebectomy under tourniquet control alone (18%). The average tourniquet time was 40 ± 12 minutes, with a median blood loss of 50 mL (interquartile range, 30-100 mL). The average follow-up was 332 ± 422 days after 19 procedures for 16 patients (2 patients moved out of state during the immediate postoperative period and 1 patient was lost to follow-up). Of the patients who completed >3 months of follow-up, 14 limbs experienced improvement in the CEAP class, 5 limbs had no change, and 3 were limbs of patients who moved or were lost to follow-up. The VCSSs significantly improved (8.8 ± 2.8 vs 3.9 ± 1.9; P < .0001). The PROs also improved significantly (16.1 ± 5.0 vs 2.2 ± 2.3; P < .0001)., Conclusions: Tourniquet use in the treatment of varicosities has only been described in the setting of high ligation and stripping. Our data suggest that in the modern era of minimally invasive endovenous treatment of axial reflux and phlebectomy, adjunct tourniquet use during the treatment of large complex varicosities can result in significant improvements in the VCSSs and PROs, with minimal blood loss., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: First-line treatment of peripheral artery disease (PAD) involves medical therapy and lifestyle modification. Multiple professional organizations such as the Society for Vascular Surgery and the American Heart Association/American College of Cardiology make Class I recommendations for medical management including antiplatelet, statin, antihypertensive, and cilostazol medications, as well as lifestyle therapy including exercise and smoking cessation. Although evidence supports up-front medical and lifestyle management prior to surgical intervention, it is unclear how well this occurs in contemporary clinical practice. It is also unclear whether variability in first-line treatment prior to revascularization is associated with postoperative outcomes. This study examined the proportion of patients with claudication actively receiving evidence-based therapy prior to surgery in a statewide surgical registry., Methods: We conducted a retrospective cohort study of adult patients undergoing elective open lower extremity bypass for claudication from 2012 to 2021 within a statewide surgical quality registry. The primary exposure was optimal medical therapy, defined as an antiplatelet agent, a statin, and an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (if the patient had hypertension) on the patient's home medication list on admission for surgery, all of which are Class I recommendations. Despite also being Class I recommendations, cilostazol was not included in the primary exposure due to its highly selective use and our inability to capture intolerance and/or contraindications that are common, and lifestyle therapies were not included as they were only recorded at the time of discharge rather than preoperatively. The primary outcomes were mortality, hospital readmission, amputation, wound complication, myocardial infarction (MI), non-patent bypass, and non-independent ambulatory status at 30 days and 1 year after surgery. Multivariable logistic regression was performed to estimate the association of receiving optimal vs non-optimal medical therapy., Results: A total of 3829 patients with claudication underwent bypass surgery during the study period, with a mean age of 64.8 years (standard deviation, 9.8 years); 2690 (70.3%) were males, and 1873 (48.9%) were current smokers. Of the patients, 1822 (47.6%) were on optimal medical therapy prior to surgery. Additionally, at discharge, 66.5% of smokers received referral to smoking cessation therapy, and 54.1% of patients received referral to exercise therapy. In a multivariable logistic regression, compared with patients not on optimal medical therapy, patients on optimal medical therapy prior to surgery had lower 30-day odds of mortality (adjusted odds ratio [aOR], 0.45; 95% confidence interval [CI], 0.26-0.78) and MI (aOR, 0.46; 95% CI, 0.28-0.76), lower 1-year odds of mortality (aOR, 0.57; 95% CI, 0.39-0.82), MI (aOR, 0.48; 95% CI, 0.32-0.74), and lower readmission (aOR, 0.79; 95% CI, 0.64-0.96)., Conclusions: Although medical and lifestyle management is recommended as first-line treatment for patients with PAD, only one-half of patients were on optimal medical therapy prior to surgery. Patients receiving optimal therapy had a lower risk of postoperative mortality, MI, and readmission. This suggests that not only are there significant opportunities to improve clinical utilization of evidence-based treatment of PAD, but that doing so can benefit patients postoperatively., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Aims: Coronary microvascular smooth muscle cells (SMCs) respond to luminal pressure by developing myogenic tone (MT), a process integral to the regulation of microvascular perfusion. The cellular mechanisms underlying poor myogenic reactivity in patients with heart valve disease are unknown and form the focus of this study., Methods and Results: Intramyocardial coronary micro-arteries (IMCAs) isolated from human and pig right atrial (RA) appendage and left ventricular (LV) biopsies were studied using pressure myography combined with confocal microscopy. All RA- and LV-IMCAs from organ donors and pigs developed circa 25% MT. In contrast, 44% of human RA-IMCAs from 88 patients with heart valve disease had poor (<10%) MT yet retained cell viability and an ability to raise cytoplasmic Ca2+ in response to vasoconstrictor agents. Comparing across human heart chambers and species, we found that based on patient medical history and six tests, the strongest predictor of poor MT in IMCAs was increased expression of the synthetic marker caldesmon relative to the contractile marker SM-myosin heavy chain. In addition, high resolution imaging revealed a distinct layer of longitudinally aligned SMCs between ECs and radial SMCs, and we show poor MT was associated with disruptions in these cellular alignments., Conclusion: These data demonstrate the first use of atrial and ventricular biopsies from patients and pigs to reveal that impaired coronary MT reflects a switch of viable SMCs towards a synthetic phenotype, rather than a loss of SMC viability. These arteries represent a model for further studies of coronary microvascular contractile dysfunction., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Heart failure is a leading cause of hospital admissions and death in the United States and worldwide. In 2016, the American Heart Association, the American College of Cardiology, and the Heart Failure Society of America released a joint focused guideline update for the management of patients with Stage C heart failure with reduced ejection fraction. An additional update released in 2017 reinforces the 2016 update's strong recommendation for substituting angiotensin-converting enzyme inhibitors or angiotensin receptor blockers with an angiotensin receptor-neprilysin inhibitor to reduce morbidity and mortality in selected patients. The 2017 and 2016 updates also support adding a sinoatrial node modulator to further reduce heart rates in patients already maximized on beta-blocker therapy. These innovative therapies can significantly improve patients' quality of life and reduce the healthcare costs associated with managing heart failure.

Objective: Prior studies identified significant racial disparities as well as regional variation in outcomes of patients with peripheral artery disease (PAD). We aimed to determine whether regional variation contributes to these racial disparities., Methods: We identified all white or black patients who underwent infrainguinal revascularization or amputation in 15 deidentified regions of the Vascular Quality Initiative between 2003 and 2017. We excluded three regions with <100 procedures. We used multivariable linear regression, allowing clustering at the hospital level to calculate the marginal effects of race and region on adjusted 30-day mortality, major adverse limb events (MALEs), and amputation. We compared long-term outcomes between black and white patients within each region and within patients of each race treated in different regions using multivariable Cox regression., Results: We identified 90,418 patients, 15,527 (17%) of whom were black. Patients underwent 31,263 bypasses, 52,462 endovascular interventions, and 6693 amputations. Black patients were younger and less likely to smoke, to have coronary artery disease, or to have chronic obstructive pulmonary disease, but they were more likely to have diabetes, limb-threatening ischemia, dialysis dependence, and hypertension and to be self-insured or on Medicaid (all P < .05). Adjusted 30-day mortality ranged from 1.2% to 2.1% across regions for white patients and 0% to 3.0% for black patients; adjusted 30-day MALE varied from 4.0% to 8.3% for white patients and 2.4% to 8.1% for black patients; and adjusted 30-day amputation rates varied from 0.3% to 1.2% for white patients and 0% to 2.1% for black patients. Black patients experienced significantly different (both higher and lower) adjusted rates of 30-day mortality and amputation than white patients did in several regions (P < .05) but not MALEs. In addition, within each racial group, we found significant variation in the adjusted rates of all outcomes between regions (all P < .01). In adjusted analyses, compared with white patients, black patients experienced consistently lower long-term mortality (hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.73-0.88; P < .001) and higher rates of MALEs (HR, 1.15; 95% CI, 1.06-1.25; P < .001) and amputation (HR, 1.33; 95% CI, 1.18-1.51; P < .001), with no statistically significant variation across the regions. However, rates of all long-term outcomes varied within both racial groups across regions., Conclusions: Significant racial disparities exist in outcomes after lower extremity procedures in patients with PAD, with regional variation contributing to perioperative but not long-term outcome disparities. Underperforming regions should use these data to generate quality improvement projects, as understanding the etiology of these disparities is critical to improving the care of all patients with PAD., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Vascular smooth muscle contraction is suppressed by feedback dilation mediated by the endothelium. In skeletal muscle arterioles, this feedback can be activated by Ca 2+ signals passing from smooth muscle through gap junctions to endothelial cells, which protrude through holes in the internal elastic lamina to make contact with vascular smooth muscle cells. Although hypothetically either Ca 2+ or inositol trisphosphate (IP 3 ) may provide the intercellular signal, it is generally thought that IP 3 diffusion is responsible. We provide evidence that Ca 2+ entry through L-type voltage-dependent Ca 2+ channels (VDCCs) in vascular smooth muscle can pass to the endothelium through positions aligned with holes in the internal elastic lamina in amounts sufficient to activate endothelial cell Ca 2+ signaling. In endothelial cells in which IP 3 receptors (IP 3 Rs) were blocked, VDCC-driven Ca 2+ events were transient and localized to the endothelium that protrudes through the internal elastic lamina to contact vascular smooth muscle cells. In endothelial cells in which IP 3 Rs were not blocked, VDCC-driven Ca 2+ events in endothelial cells were amplified to form propagating waves. These waves activated voltage-insensitive, intermediate-conductance, Ca 2+ -activated K + (IK Ca ) channels, thereby providing feedback that effectively suppressed vasoconstriction and enabled cycles of constriction and dilation called vasomotion. Thus, agonists that stimulate vascular smooth muscle depolarization provide Ca 2+ to endothelial cells to activate a feedback circuit that protects tissue blood flow., (Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The artery wall is equipped with a water permeation barrier that allows blood to flow at high pressure without significant water leak. The precise location of this barrier is unknown despite its importance in vascular function and its contribution to many vascular complications when it is compromised. Herein we map the water permeability in intact arteries, using coherent anti-Stokes Raman scattering (CARS) microscopy and isotopic perfusion experiments. Generation of the CARS signal is optimized for water imaging with broadband excitation. We identify the water permeation barrier as the endothelial basolateral membrane and show that the apical membrane is highly permeable. This is confirmed by the distribution of the AQP1 water channel within endothelial membranes. These results indicate that arterial pressure equilibrates within the endothelium and is transmitted to the supporting basement membrane and internal elastic lamina macromolecules with minimal deformation of the sensitive endothelial cell. Disruption of this pressure transmission could contribute to endothelial cell dysfunction in various pathologies., Competing Interests: The authors declare no conflict of interest.